AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE RENO NV 940 PM PST FRI MAR 7 2008 .UPDATE... ONGOING SHORT TERM FORECAST IS IN GOOD SHAPE THIS EVENING. HAVE MADE A FEW MINOR EDITS TO CLOUD COVER BASED ON SATELLITE TRENDS...WHICH SHOW AN AREA OF THICK MID-LEVEL CLOUDS ROLLING ACROSS THE CWA ATTM. UPSTREAM RADARS ARE SHOWING A FEW LIGHT SHOWERS ACROSS SRN OREGON...SO WILL CONTINUE LOW CHC POPS IN OUR FAR NORTHERN ZONES OVERNIGHT. WINDS HAD INCREASED EARLIER ON THE RIDGES AT SLIDE MTN AND SQUAW SUMMIT (~40 MPH)...BUT HAVE SINCE DECREASED A BIT. STILL BASED ON THE LATEST RUC 700MB WIND FORECASTS...WE SHOULD SEE RIDGE GUSTS PICK BACK UP AGAIN AFTER MIDNIGHT AS MID LEVEL SHORT WAVE AND ASSOC WIND SPEED MAX MOVE INTO THE AREA. WE MAY SEE A PERIOD OF GUSTY WINDS (20-25KTS) NEAR LAKE TAHOE IN THE MORNING. SOMETHING TO WATCH. INTO THE WRN NV VALLEYS...IF WE CAN MIX UP TO 700MB ON SATURDAY THEN GUSTS MAY BE A BIT HIGHER THAN CURRENTLY FORECAST. FORECAST UPDATES OUT BY 10 PM PST. CS && .PREVIOUS DISCUSSION... /ISSUED 230 PM PST FRI MAR 7 2008/ SHORT TERM... A WEAK SYSTEM APPROACHING THE SOUTHERN OREGON COAST IS SPREADING HIGH CLOUDS ACROSS THE CWA...WITH PERHAPS A FEW MID CLOUDS FAR NORTH. A FEW LIGHT SHOWERS ARE POSSIBLE TONIGHT NORTH OF A SUSANVILLE TO GERLACH LINE. TONIGHT`S GLANCING BLOW SYSTEM WILL KICK THROUGH SATURDAY MORNING... BRINGING NORTHWEST WINDS AS A COOL SURFACE HIGH BUILDS INTO THE GREAT BASIN. THE HIGH WILL KNOCK HIGHS BACK DOWN TO SEASONABLE NORMALS (50S FOR THE LOWER VALLEYS) EVERYWHERE FOR SATURDAY. SATURDAY NIGHT THROUGH SUNDAY NIGHT...AN UPPER RIDGE BUILDS BACK IN TO RAISE HIGHS TO A FEW DEGREES ABOVE NORMAL FOR SUNDAY AFTERNOON. MONDAY AFTERNOON AND MONDAY NIGHT...ANOTHER WEAK GLANCING SYSTEM MOVES INTO THE MEAN UPPER RIDGE AND THROUGH THE REGION. THIS WILL BRING THE SLIGHT CHANCE OF SHOWERS DOWN TO INTERSTATE 80...WITH A CHANCE FAR NORTH. SNYDER LONG TERM...TUESDAY THROUGH FRIDAY... NORTHWEST FLOW ALOFT IN POST FRONTAL AIR MASS ON TUESDAY WILL PRODUCE TEMPS ABOUT 4-8 DEGREES COOLER TO NEAR SEASONAL NORMALS OF UPPER 50S IN MOST VALLEYS ON TUESDAY. ANY LINGERING SHOWERS WILL BE SHORT LIVED AND LIMITED TO THE NORTH ZONES. FLAT RIDGE REBUILDS INTO THE REGION ON WEDNESDAY WITH AREAS OF HIGH CLOUDS AND TEMPS REBOUNDING A FEW DEGREES. BY THE END OF NEXT WEEK...A PATTERN CHANGE TO COLDER AND WETTER IS LOOKING MORE LIKELY AS BOTH THE 12Z GFS AND ECMWF BUILD A LONGWAVE TROF ALONG THE WEST COAST...WITH A FEW OF THE ENSEMBLE MEMBERS ALSO FAVORING THIS SCENARIO. THE TRANSITION WILL BEGIN ON THURSDAY AS FLOW ALOFT BECOMES MORE ZONAL...BRINGING AN INCREASE IN WINDS AND MORE OVERRUNNING MID-HIGH LEVEL MOISTURE ESPECIALLY IN THE NORTH WHERE A FEW SHOWERS MAY DEVELOP. WITH THE COLD AIR MASS STILL NORTH OF THE REGION...TEMPS SHOULD REMAIN ABOVE NORMAL WITH IMPROVED MIXING...AND REMAIN MILD THURS NIGHT AS WINDS ARE LESS LIKELY TO DECOUPLE. THE COOLING TREND SHOULD BECOME MORE NOTICEABLE ON FRIDAY AS TROF AND COLD FRONT ARE PROJECTED TO PASS THRU THE REGION WITH PRECIP CHANCES INCREASING IN THE SIERRA AND PARTS OF WRN NV. BY NEXT FRI NIGHT AND INTO NEXT WEEKEND THE POTENTIAL FOR ACCUMULATING SNOW WILL INCREASE EVEN IN LOWER VALLEYS. IF THE LATEST ECMWF SHOWING OVER-WATER TRAJECTORY IN THE 500 MB FLOW WITH FAVORABLE JET DYNAMICS AND PLENTY OF COLD UNSTABLE AIR IN PLACE...SNOW AMOUNTS COULD BE SIGNIFICANT ESPECIALLY IN THE SIERRA. MJD AVIATION... WEST WIND GUSTS TO 20-25 KT AHEAD OF COLD FRONT FOR LEE SIDE VALLEYS OF WRN NV WILL CONTINUE UNTIL AROUND 06Z TONIGHT...WITH NORTHWEST GUSTS NEAR 25 KT ON SATURDAY MAINLY AFT 18Z. GUSTS ON SIERRA RIDGES UP TO 60 KT THRU SATURDAY PRODUCING SOME MOUNTAIN WAVE ACTIVITY. OTHERWISE VFR CIGS/VSBY EXPECTED THRU THIS WEEKEND WITH WDSPRD MID-HI LVL CLOUD COVER DECREASING LATE TONIGHT. MJD && .REV WATCHES/WARNINGS/ADVISORIES... NV...NONE. CA...NONE. && $$ HTTP://WEATHER.GOV/RENO ca AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PUEBLO CO 717 AM MDT SUN MAR 9 2008 .UPDATED... CANCELLED THE FINAL PORTION OF THE SNOW ADVISORY ACROSS THE WET MOUNTAINS...SANGRE DE CRISTO MOUNTAINS...AND SOUTHERN FOOTHILLS BASED ON DECREASING COVERAGE AND INTENSITY OF SNOWFALL PER PUB RADAR DATA. && .PREV DISCUSSION... /ISSUED 601 AM MDT SUN MAR 9 2008/ UPDATE... (THIS MORNING) SNOW HAS BEEN QUICKLY WANING ACROSS CHAFFEE AND FREMONT COUNTY EARLY THIS MORNING. THUS AS ANTICIPATED IN DISCUSSION BELOW...HAVE BEGUN THE PROCESS OF PARING OUT NORTHERN SECTIONS OF THE ADVISORY AREA. SHORT TERM... (TODAY AND TONIGHT) UPPER LOW BACK OVER NRN AZ/NW NM WILL CONTINUE TO DROP SOUTHEASTWARD INTO EXTREME SOUTHERN NM BY 00Z MON. CURRENT RADAR INDICATES SOME FAIRLY WIDESPREAD PRECIPITATION ECHOES ALONG THE EASTERN SLOPES OF THE SE MTS...MAINLY WETS...SANGRES...AND THE ARKANSAS RIVER VALLEY OF FREMONT COUNTY. MYP HAS BEEN REPORTING +SN OFF AND ON...AND WEB CAMS FROM UP THAT WAY SUGGEST A COUPLE INCHES OR SO MAY HAVE ACCUMULATED SINCE AROUND MIDNIGHT. OVERALL...SYSTEM NOT THAT IMPRESSIVE IN SATELLITE LOOPS. BEST DYNAMICS/ISENTROPIC LIFT IS OCCURRING NOW THROUGH AROUND 15Z...THEN IT WANES QUICKLY THROUGH THE LATE MORNING AS THE SYSTEM CONTINUES TO DROP SOUTHWARD. DEFORMATION BAND APPEARS PRETTY FRAGMENTED AND ILL DEFINED. WILL MAINTAIN THE SNOW ADVISORY FOR MOST AREAS...THOUGH WILL BEGIN TO SHAVE OFF SOME OF THE NORTHERN SECTIONS OF LAKE AND EASTERN CHAFFEE COUNTIES. H7 WINDS DON`T APPEAR ALL THAT STRONG IN EITHER MODEL NOW...NAM OR GFS...SO DON`T THINK WESTERN SECTIONS OF THE SAN LUIS VALLEY WILL RECEIVE MUCH IN THE WAY OF HEAVY SNOW...SO WILL ALSO REMOVE THE ADVISORY FOR ZONE 65. FOR THE REMAINDER OF THE ADVISORY AREA...TOTAL ACCUMULATIONS OF 3 TO 8 INCHES CAN BE EXPECTED...WITH THE HEAVIEST ACCUMS ALONG THE EAST SLOPES OF THE WETS AND SANGRES. SNOW WILL GRADUALLY END BY THIS AFTERNOON FOR MOST AREAS AS WEAK EASTERLY UPSLOPE FLOW BECOMES MORE SOUTHWESTERLY. LEE TROF REDEVELOPS TOWARDS DAWN...AND H7 TEMPS BEHIND THIS SYSTEM ARE NOT ALL THAT COLD. MIN TEMPS MAY BE HIT AROUND/BEFORE MIDNIGHT...WITH WESTERLY DRAINAGE FLOW KICKING IN ACROSS THE LOWER EASTERN SLOPES AFTER 06Z CAUSING TEMPS TO STAY STEADY...OR EVEN WARM SLIGHTLY. -KT LONG TERM... (MONDAY THROUGH SATURDAY) ..ACTIVE WEATHER PATTERN TO CONTINUE THIS WEEK... MONDAY...INTERESTING LITTLE WEATHER FEATURE TO DROP SOUTHWARD ON THE BACKSIDE OF THE WEATHER SYSTEM CURRENTLY MOVING THROUGH THE GREAT BASIN. THE WEATHER FEATURE...UPPER LEVEL JET STREAK AND ASSOCIATED LOW/SHORTWAVE TROUGH...IS CURRENTLY OVER WESTERN MT PER WATER VAPOR AND RUC MODEL UPPER AIR ANALYSES. GFS/ECMWF HAS THIS FEATURE DROPPING THROUGH WESTERN CO DURING MONDAY AFTERNOON. NAM- WRF KIND OF HAS THIS FEATURE...BUT NOT PRINTING OUT MUCH IN THE WAY OF QPF. WEATHER FEATURE SHOULD BE MOVING THROUGH THE CENTRAL ROCKIES DURING PEAK HEATING AND INSTABILITY...MIDLEVEL LAPSE RATE OF 7-8 C/KM WOULD SUPPORT AT LEAST A SMALL CHANCE FOR CONVECTIVE PRECIPITATION OVER THE MOUNTAINS/HIGH VALLEYS. THE CURRENT FORECAST HAS SOMETHING TO THIS EXTENT...BUT POPS MIGHT NEED TO BE BUMPED UP A LITTLE OVER THE MOUNTAINS/HIGH VALLEYS IF FUTURE MODELS CONTINUE THIS TREND. TUESDAY THROUGH SATURDAY...OVERALL A PROGRESSIVE WESTERLY FLOW PATTERN APPEARS TO BE TAKING SHAPE WITH WEATHER FEATURES MOVING RAPIDLY THROUGH THE CENTRAL ROCKIES. IN GENERAL...TEMPERATURES ARE FORECAST TO BE AT OR SLIGHTLY ABOVE MARCH AVERAGE READINGS. THE BETTER CHANCE FOR PRECIPITATION SHOULD BE ACROSS THE MOUNTAINS... ESPECIALLY THE CONTINENTAL DIVIDE WEDNESDAY AND AGAIN FRIDAY AND SATURDAY. POTENTIAL EXISTS FOR MORE SNOWFALL ACROSS THE CONTINENTAL DIVIDE FRIDAY AND SATURDAY. BREEZY/WINDY CONDITIONS WILL BE LIKELY TUESDAY THROUGH SATURDAY. 17 AVIATION... MVFR/VFR CIGS EXPECTED ACROSS KCOS/KPUB TAF SITES THROUGH THE MORNING...WITH CLEARING SKIES BY LATE AFTERNOON AND EVENING. FOR THE SOUTHERN MTS/FOOTHILLS/HIGH VALLEYS...WIDESPREAD SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING WITH IFR TO LIFR CIGS ALONG THE EASTERN SLOPES AND HIGHER TERRAIN WHERE EASTERLY UPSLOPE FLOW WILL CONTINUE. KALS MAY SEE SOME MVFR TO BRIEF IFR UNDER SNOW SHOWERS THROUGH THE MORNING. IMPROVING CONDITIONS EXPECTED FOR ALL OF THE AREA DURING THE AFTERNOON AND EVENING WITH SOME PERSISTENT ISOLATED TO SCATTERED SNOW SHOWERS CONTINUING ALONG THE CONTDVD THROUGH THE EVENING. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 17/17 co AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PUEBLO CO 601 AM MDT SUN MAR 9 2008 .UPDATE... (THIS MORNING) SNOW HAS BEEN QUICKLY WANING ACROSS CHAFFEE AND FREMONT COUNTY EARLY THIS MORNING. THUS AS ANTICIPATED IN DISCUSSION BELOW...HAVE BEGUN THE PROCESS OF PARING OUT NORTHERN SECTIONS OF THE ADVISORY AREA. && .SHORT TERM... (TODAY AND TONIGHT) UPPER LOW BACK OVER NRN AZ/NW NM WILL CONTINUE TO DROP SOUTHEASTWARD INTO EXTREME SOUTHERN NM BY 00Z MON. CURRENT RADAR INDICATES SOME FAIRLY WIDESPREAD PRECIPITATION ECHOES ALONG THE EASTERN SLOPES OF THE SE MTS...MAINLY WETS...SANGRES...AND THE ARKANSAS RIVER VALLEY OF FREMONT COUNTY. MYP HAS BEEN REPORTING +SN OFF AND ON...AND WEB CAMS FROM UP THAT WAY SUGGEST A COUPLE INCHES OR SO MAY HAVE ACCUMULATED SINCE AROUND MIDNIGHT. OVERALL...SYSTEM NOT THAT IMPRESSIVE IN SATELLITE LOOPS. BEST DYNAMICS/ISENTROPIC LIFT IS OCCURRING NOW THROUGH AROUND 15Z...THEN IT WANES QUICKLY THROUGH THE LATE MORNING AS THE SYSTEM CONTINUES TO DROP SOUTHWARD. DEFORMATION BAND APPEARS PRETTY FRAGMENTED AND ILL DEFINED. WILL MAINTAIN THE SNOW ADVISORY FOR MOST AREAS...THOUGH WILL BEGIN TO SHAVE OFF SOME OF THE NORTHERN SECTIONS OF LAKE AND EASTERN CHAFFEE COUNTIES. H7 WINDS DON`T APPEAR ALL THAT STRONG IN EITHER MODEL NOW...NAM OR GFS...SO DON`T THINK WESTERN SECTIONS OF THE SAN LUIS VALLEY WILL RECEIVE MUCH IN THE WAY OF HEAVY SNOW...SO WILL ALSO REMOVE THE ADVISORY FOR ZONE 65. FOR THE REMAINDER OF THE ADVISORY AREA...TOTAL ACCUMULATIONS OF 3 TO 8 INCHES CAN BE EXPECTED...WITH THE HEAVIEST ACCUMS ALONG THE EAST SLOPES OF THE WETS AND SANGRES. SNOW WILL GRADUALLY END BY THIS AFTERNOON FOR MOST AREAS AS WEAK EASTERLY UPSLOPE FLOW BECOMES MORE SOUTHWESTERLY. LEE TROF REDEVELOPS TOWARDS DAWN...AND H7 TEMPS BEHIND THIS SYSTEM ARE NOT ALL THAT COLD. MIN TEMPS MAY BE HIT AROUND/BEFORE MIDNIGHT...WITH WESTERLY DRAINAGE FLOW KICKING IN ACROSS THE LOWER EASTERN SLOPES AFTER 06Z CAUSING TEMPS TO STAY STEADY...OR EVEN WARM SLIGHTLY. -KT .LONG TERM... (MONDAY THROUGH SATURDAY) ...ACTIVE WEATHER PATTERN TO CONTINUE THIS WEEK... MONDAY...INTERESTING LITTLE WEATHER FEATURE TO DROP SOUTHWARD ON THE BACKSIDE OF THE WEATHER SYSTEM CURRENTLY MOVING THROUGH THE GREAT BASIN. THE WEATHER FEATURE...UPPER LEVEL JET STREAK AND ASSOCIATED LOW/SHORTWAVE TROUGH...IS CURRENTLY OVER WESTERN MT PER WATER VAPOR AND RUC MODEL UPPER AIR ANALYSES. GFS/ECMWF HAS THIS FEATURE DROPPING THROUGH WESTERN CO DURING MONDAY AFTERNOON. NAM- WRF KIND OF HAS THIS FEATURE...BUT NOT PRINTING OUT MUCH IN THE WAY OF QPF. WEATHER FEATURE SHOULD BE MOVING THROUGH THE CENTRAL ROCKIES DURING PEAK HEATING AND INSTABILITY...MIDLEVEL LAPSE RATE OF 7-8 C/KM WOULD SUPPORT AT LEAST A SMALL CHANCE FOR CONVECTIVE PRECIPITATION OVER THE MOUNTAINS/HIGH VALLEYS. THE CURRENT FORECAST HAS SOMETHING TO THIS EXTENT...BUT POPS MIGHT NEED TO BE BUMPED UP A LITTLE OVER THE MOUNTAINS/HIGH VALLEYS IF FUTURE MODELS CONTINUE THIS TREND. TUESDAY THROUGH SATURDAY...OVERALL A PROGRESSIVE WESTERLY FLOW PATTERN APPEARS TO BE TAKING SHAPE WITH WEATHER FEATURES MOVING RAPIDLY THROUGH THE CENTRAL ROCKIES. IN GENERAL...TEMPERATURES ARE FORECAST TO BE AT OR SLIGHTLY ABOVE MARCH AVERAGE READINGS. THE BETTER CHANCE FOR PRECIPITATION SHOULD BE ACROSS THE MOUNTAINS... ESPECIALLY THE CONTINENTAL DIVIDE WEDNESDAY AND AGAIN FRIDAY AND SATURDAY. POTENTIAL EXISTS FOR MORE SNOWFALL ACROSS THE CONTINENTAL DIVIDE FRIDAY AND SATURDAY. BREEZY/WINDY CONDITIONS WILL BE LIKELY TUESDAY THROUGH SATURDAY. METZE && .AVIATION... MVFR/VFR CIGS EXPECTED ACROSS KCOS/KPUB TAF SITES THROUGH THE MORNING...WITH CLEARING SKIES BY LATE AFTERNOON AND EVENING. FOR THE SOUTHERN MTS/FOOTHILLS/HIGH VALLEYS...WIDESPREAD SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING WITH IFR TO LIFR CIGS ALONG THE EASTERN SLOPES AND HIGHER TERRAIN WHERE EASTERLY UPSLOPE FLOW WILL CONTINUE. KALS MAY SEE SOME MVFR TO BRIEF IFR UNDER SNOW SHOWERS THROUGH THE MORNING. IMPROVING CONDITIONS EXPECTED FOR ALL OF THE AREA DURING THE AFTERNOON AND EVENING WITH SOME PERSISTENT ISOLATED TO SCATTERED SNOW SHOWERS CONTINUING ALONG THE CONTDVD THROUGH THE EVENING. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... SNOW ADVISORY UNTIL NOON MDT TODAY FOR COZ072>075-078>080-087- 088. && $$ 31/17 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 349 AM MDT SUN MAR 9 2008 .SHORT TERM... (TODAY AND TONIGHT) UPPER LOW BACK OVER NRN AZ/NW NM WILL CONTINUE TO DROP SOUTHEASTWARD INTO EXTREME SOUTHERN NM BY 00Z MON. CURRENT RADAR INDICATES SOME FAIRLY WIDESPREAD PRECIPITATION ECHOES ALONG THE EASTERN SLOPES OF THE SE MTS...MAINLY WETS...SANGRES...AND THE ARKANSAS RIVER VALLEY OF FREMONT COUNTY. MYP HAS BEEN REPORTING +SN OFF AND ON...AND WEB CAMS FROM UP THAT WAY SUGGEST A COUPLE INCHES OR SO MAY HAVE ACCUMULATED SINCE AROUND MIDNIGHT. OVERALL...SYSTEM NOT THAT IMPRESSIVE IN SATELLITE LOOPS. BEST DYNAMICS/ISENTROPIC LIFT IS OCCURRING NOW THROUGH AROUND 15Z...THEN IT WANES QUICKLY THROUGH THE LATE MORNING AS THE SYSTEM CONTINUES TO DROP SOUTHWARD. DEFORMATION BAND APPEARS PRETTY FRAGMENTED AND ILL DEFINED. WILL MAINTAIN THE SNOW ADVISORY FOR MOST AREAS...THOUGH WILL BEGIN TO SHAVE OFF SOME OF THE NORTHERN SECTIONS OF LAKE AND EASTERN CHAFFEE COUNTIES. H7 WINDS DON`T APPEAR ALL THAT STRONG IN EITHER MODEL NOW...NAM OR GFS...SO DON`T THINK WESTERN SECTIONS OF THE SAN LUIS VALLEY WILL RECEIVE MUCH IN THE WAY OF HEAVY SNOW...SO WILL ALSO REMOVE THE ADVISORY FOR ZONE 65. FOR THE REMAINDER OF THE ADVISORY AREA...TOTAL ACCUMULATIONS OF 3 TO 8 INCHES CAN BE EXPECTED...WITH THE HEAVIEST ACCUMS ALONG THE EAST SLOPES OF THE WETS AND SANGRES. SNOW WILL GRADUALLY END BY THIS AFTERNOON FOR MOST AREAS AS WEAK EASTERLY UPSLOPE FLOW BECOMES MORE SOUTHWESTERLY. LEE TROF REDEVELOPS TOWARDS DAWN...AND H7 TEMPS BEHIND THIS SYSTEM ARE NOT ALL THAT COLD. MIN TEMPS MAY BE HIT AROUND/BEFORE MIDNIGHT...WITH WESTERLY DRAINAGE FLOW KICKING IN ACROSS THE LOWER EASTERN SLOPES AFTER 06Z CAUSING TEMPS TO STAY STEADY...OR EVEN WARM SLIGHTLY. -KT .LONG TERM... (MONDAY THROUGH SATURDAY) ...ACTIVE WEATHER PATTERN TO CONTINUE THIS WEEK... MONDAY...INTERESTING LITTLE WEATHER FEATURE TO DROP SOUTHWARD ON THE BACKSIDE OF THE WEATHER SYSTEM CURRENTLY MOVING THROUGH THE GREAT BASIN. THE WEATHER FEATURE...UPPER LEVEL JET STREAK AND ASSOCIATED LOW/SHORTWAVE TROUGH...IS CURRENTLY OVER WESTERN MT PER WATER VAPOR AND RUC MODEL UPPER AIR ANALYSES. GFS/ECMWF HAS THIS FEATURE DROPPING THROUGH WESTERN CO DURING MONDAY AFTERNOON. NAM- WRF KIND OF HAS THIS FEATURE...BUT NOT PRINTING OUT MUCH IN THE WAY OF QPF. WEATHER FEATURE SHOULD BE MOVING THROUGH THE CENTRAL ROCKIES DURING PEAK HEATING AND INSTABILITY...MIDLEVEL LAPSE RATE OF 7-8 C/KM WOULD SUPPORT AT LEAST A SMALL CHANCE FOR CONVECTIVE PRECIPITATION OVER THE MOUNTAINS/HIGH VALLEYS. THE CURRENT FORECAST HAS SOMETHING TO THIS EXTENT...BUT POPS MIGHT NEED TO BE BUMPED UP A LITTLE OVER THE MOUNTAINS/HIGH VALLEYS IF FUTURE MODELS CONTINUE THIS TREND. TUESDAY THROUGH SATURDAY...OVERALL A PROGRESSIVE WESTERLY FLOW PATTERN APPEARS TO BE TAKING SHAPE WITH WEATHER FEATURES MOVING RAPIDLY THROUGH THE CENTRAL ROCKIES. IN GENERAL...TEMPERATURES ARE FORECAST TO BE AT OR SLIGHTLY ABOVE MARCH AVERAGE READINGS. THE BETTER CHANCE FOR PRECIPITATION SHOULD BE ACROSS THE MOUNTAINS... ESPECIALLY THE CONTINENTAL DIVIDE WEDNESDAY AND AGAIN FRIDAY AND SATURDAY. POTENTIAL EXISTS FOR MORE SNOWFALL ACROSS THE CONTINENTAL DIVIDE FRIDAY AND SATURDAY. BREEZY/WINDY CONDITIONS WILL BE LIKELY TUESDAY THROUGH SATURDAY. METZE && .AVIATION... MVFR/VFR CIGS EXPECTED ACROSS KCOS/KPUB TAF SITES THROUGH THE MORNING...WITH CLEARING SKIES BY LATE AFTERNOON AND EVENING. FOR THE SOUTHERN MTS/FOOTHILLS/HIGH VALLEYS...WIDESPREAD SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING WITH IFR TO LIFR CIGS ALONG THE EASTERN SLOPES AND HIGHER TERRAIN WHERE EASTERLY UPSLOPE FLOW WILL CONTINUE. KALS MAY SEE SOME MVFR TO BRIEF IFR UNDER SNOW SHOWERS THROUGH THE MORNING. IMPROVING CONDITIONS EXPECTED FOR ALL OF THE AREA DURING THE AFTERNOON AND EVENING WITH SOME PERSISTENT ISOLATED TO SCATTERED SNOW SHOWERS CONTINUING ALONG THE CONTDVD THROUGH THE EVENING. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... SNOW ADVISORY UNTIL NOON MDT TODAY FOR COZ060>062-072>080-087- 088. && $$ 31/17 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 956 PM EST SAT MAR 8 2008 .SYNOPSIS... LOW PRESSURE IN SOUTHERN NEW YORK STATE EARLY TONIGHT WILL MOVE UP INTO NORTHERN NEW ENGLAND BY SUNDAY MORNING. THIS WILL CAUSE STRONG AND GUSTY WEST WINDS FOR OUR AREA OVERNIGHT AND SUNDAY. HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST LATE SUNDAY, BUT MOVE OFFSHORE SUNDAY NIGHT. A WEAK LOW PRESSURE SYSTEM AND ASSOCIATED FRONTAL BOUNDARY MAY CROSS THE AREA MONDAY, WITH ANOTHER ONE POSSIBLE WEDNESDAY. THESE SYSTEMS ARE EXPECTED TO BE WEAK AND NOT PRODUCE MUCH IN THE WAY OF PRECIPITATION. HIGH PRESSURE IS FORECAST TO RETURN BRIEFLY THURSDAY, FOLLOWED WITH ANOTHER LOW PRESSURE SYSTEM AND COLD FRONT BY THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... THE LOW IS MOVING UP THROUGH NEW YORK STATE, AND THE GRADIENT, WHILE MAYBE BECOMING EVEN A SMIDGEN TIGHTER THAN IT IS AT 02Z, IS NOT EXPECTED TO PRODUCE WIND GUSTS UP TO HIGH WIND LEVELS. SO, THE HIGH WIND WARNING FOR THE NORTHERN HALF OF THE AREA WAS DOWNGRADED TO A WIND ADVISORY, WHICH IS UP EVERYWHERE UNTIL 11Z (7 AM EDT). CYCLONIC FLOW AT THE SURFACE AND THE MID LEVEL TROF AXIS LINGER FOR A WHILE ONCE THE COLD FRONT IS THROUGH AND THE SURFACE LOW IS WELL NORTH OF US, SO WE`LL MAINTAIN A SLIGHT CHANCE OF SNOW SHOWERS IN THE FAR NORTHWEST OVERNIGHT. ACKNOWLEDGING THAT THERE WILL BE FLOODING FOR A WHILE AFTER THE BULK OF THE RAIN, WE`VE ALLOWED THE FLOOD WATCH TO EXPIRE AT 6 PM AND WILL HANDLE FLOODING WITH WARNINGS, ADVISORIES AND STATEMENTS. THE WEATHER STORY HAS TRANSITIONED TO THE WIND. MODELS SHOW H8 WINDS AT OR ABOVE 50 KT BY 00Z AND CONTINUING THROUGH 06Z, WITH VERY SIGNIFICANT PRESSURE RISES SWEEPING ACROSS THE AREA NEAR AND NORTHWEST OF THE INTERSTATE 95 CORRIDOR. STRONG NVA ACCOMPANIES A JET AT H5 IN EXCESS OF 100 KTS, AND THAT JET RUNS ALONG THE EAST SIDE OF A NEGATIVE TILT TROF AXIS EMANATING FROM THE H5 CUTOFF. THIS, ACCORDING TO AN IN-HOUSE DECISION TREE, SPELLS WIND GUSTS AROUND 50 KT. THE BUFKIT SOUNDINGS SUPPORT GUSTS TO AROUND 45 KT IN THE SAME AREA. WINDS SHOULD BEGIN TO DIMINISH DURING THE PRE-DAWN HOURS. WE HAVEN`T DEVIATED TOO MUCH FROM THE PREVIOUS FORECAST REGARDING TEMPERATURES, AS THAT DOESN`T SEEM TO BE WHERE THE BULK OF THE ACTION IS IN THE FIRST PERIOD. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... FRANKLY, THE BULK OF THE ACTION IS IN THE NEAR TERM. WINDS WILL DIMINISH GRADUALLY DURING THE DAY ON SUNDAY, AS A SURFACE HIGH PRESSURE RIDGE WILL DRIFT ACROSS THE AREA SUNDAY NIGHT AND EARLY MONDAY. A CONSIDERABLY WEAKER MID LEVEL IMPULSE WILL MOVE TOWARD US MONDAY AND CROSS THE AREA MONDAY NIGHT. WE HAVE PUT IN SOME CHANCE POPS FOR THE SOUTHERN ZONES ON MONDAY NIGHT, BUT THE AMOUNT OF PRECIPITATION EXPECTED IS VIRTUALLY NIL. WE`VE STAYED CLOSE TO A COMBINATION OF GUIDANCE AND CONTINUITY ON TEMPERATURES THROUGH THE PERIOD. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THE FORECAST LOOKS RELATIVELY DRY THROUGH THE MAJORITY OF THE EXTENDED PERIOD. THE PERIOD STARTS OFF WITH HIGH PRESSURE OFF TO THE SOUTHWEST. THIS HIGH STAYS JUST TO THE SOUTHWEST OF THE REGION WEDNESDAY AS A WEAK TROUGH MOVES ACROSS THE AREA. THIS TROUGH COULD BRING SOME LIGHT SHOWERS ON WEDNESDAY, MAINLY JUST TO THE POCONOS AND LEHIGH VALLEY, BUT NOTHING SIGNIFICANT IS EXPECTED AT THIS TIME. A BRIEF PERIOD OF HIGH PRESSURE WILL FOLLOW FOR THURSDAY AND THURSDAY NIGHT. THE NEXT WEATHER MAKER LOOKS TO BE AT THE END OF THE WORK WEEK AS A TROUGH APPROACHES THE REGION FROM THE WEST. A LOW PRESSURE SYSTEM LOCATED OVER NORTHEASTERN CANADA, WILL TRY TO DRAG A COLD FRONT ACROSS THE REGION EARLY FRIDAY. HOWEVER, ANOTHER LOW OVER THE MISSISSIPPI VALLEY WILL MAKE ITS WAY NORTHEAST AND PASS RIGHT OVER THE REGION LATE FRIDAY INTO SATURDAY. FOLLOWED ALONG THE LINES OF HPC FOR THE MOST PART BUT DID MAKE OCCASIONAL ADJUSTMENTS BASED ON MOS GUIDANCE. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... SHOWERS AND THUNDERSTORMS HAD EXITED THE AREA AND TAF SITES HAD RETURNED MOSTLY TO VFR (KABE HAD A MARGINAL VFR CEILING), WITH JUST A COUPLE OF LIGHT LEFTOVER ECHOES ON RADAR. NOW, STRONG WINDS AND WIND GUSTS WILL BE THE STORY FOR THE NEXT 36 HOURS OR SO. THE RUC WAS QUITE GOOD IN DEPICTING STRONG DEVELOPMENT OF WINDS (AND, IN RETROSPECT, THUNDERSTORM DEVELOPMENT) BETWEEN 22Z AND 23Z. WINDS WILL BE QUITE STRONG, WITH GUSTS REACHING 40 TO 45 KNOTS TONIGHT, AND PERHAPS SLACKING OFF A BIT LATE TONIGHT AND A BIT MORE SUNDAY, BEFORE REALLY DROPPING OFF LATER SUNDAY AFTERNOON AS THE GRADIENT MOVES OUT OF THE AREA AND HIGH PRESSURE BRIEFLY BUILDS INTO THE REGION. BEYOND THE TAF PERIOD, THERE ARE SEVERAL WEAK SYSTEMS THAT ARE FORECAST TO MOVE THROUGH THE AREA. ONE BEING ON MONDAY, ANOTHER ON WEDNESDAY, AND ANOTHER BEING NEXT FRIDAY. THE SYSTEM NEXT FRIDAY WILL LIKELY HAVE THE GREATEST IMPACT, ALTHOUGH THE FIRST TWO COULD PRODUCE SOME SHOWER ACTIVITY ACROSS THE AREA. && .MARINE... A COLD FRONT WILL MOVE ACROSS THE WATERS TONIGHT, WITH A STRONG WEST TO NORTHWEST FLOW BEHIND IT. WE HAVE CONTINUED THE GALE WARNING FOR THE DELAWARE BAY AND COASTAL WATERS SOUTH OF LITTLE EGG INLET. NORTH OF LITTLE EGG INLET, WE HAVE ISSUED A STORM WARNING FOR THE OVERNIGHT HOURS AS THERE MAY BE A PERIOD OF STORM FORCE WINDS IN THE NORTHERN SECTIONS OVERNIGHT TONIGHT. THESE WINDS SHOULD BEGIN TO DIMINISH TOWARD DAYBREAK TOMORROW, BUT EVERYONE SHOULD STILL EXPERIENCE GALES THROUGH THE MORNING SUNDAY. BY SUNDAY AFTERNOON, WINDS SHOULD DIMINISH TO SMALL CRAFT CRITERIA AND WILL LIKELY LAST THROUGH SUNDAY EVENING. SMALL CRAFT CRITERIA ARE NOT EXPECTED THROUGH THE REST OF THE FORECAST PERIOD, ALTHOUGH THERE ARE A COUPLE OF WEAK SYSTEMS THAT MAY MOVE THROUGH THE AREA MONDAY OR WEDNESDAY. THEY SHOULD NOT CAUSE ANY PROBLEMS HOWEVER. && .HYDROLOGY... THE FLOOD WATCH HAS EXPIRED, AND ALL SUBSEQUENT FLOODING CONCERNS FROM THIS SYSTEM WILL BE HANDLED BY WARNINGS, ADVISORIES AND STATEMENTS. && .TIDES/COASTAL FLOODING... LOW TIDE WAS APPROACHING FOR THE EASTERN MARYLAND SHORE AREAS AS OF 0145Z, AND THAT`S FORTUNATE BECAUSE THE ANOMALIES HAVE MAINTAINED ABOUT PLUS 2 FEET. HOWEVER, THIS SHOULD NOT PRODUCE ANY MORE MINOR TIDAL FLOODING, AND AS WINDS VEER OVER THE NEXT FEW HOURS, ANOMALIES SHOULD DIMINISH. A LOW WATER ADVISORY HAS BEEN ISSUED FOR THE COASTAL WATERS AND DELAWARE BAY FOR THE LOW TIDE CYCLE SUNDAY MORNING. WITH THE STRONG WEST TO NORTHWEST WINDS, BLOW-OUT TIDES ARE EXPECTED. PLEASE REFER TO THE LATEST MARINE WEATHER STATEMENT FOR DETAILS. THE LOW TIDE ON SUNDAY NIGHT COULD POSSIBLY REACH BLOW- OUT CONDITIONS AGAIN, SO WE WILL NEED TO CONTINUE TO MONITOR THE FORECAST FOR FUTURE UPDATES. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 AM EDT SUNDAY FOR PAZ054-055-060>062- 067>071. NJ...WIND ADVISORY UNTIL 7 AM EDT SUNDAY FOR NJZ001-007>010-012>027. DE...WIND ADVISORY UNTIL 7 AM EDT SUNDAY FOR DEZ001>004. MD...WIND ADVISORY UNTIL 7 AM EDT SUNDAY FOR MDZ008-012-015-019-020. MARINE...LOW WATER ADVISORY UNTIL 7 AM EDT SUNDAY FOR ANZ450>455. GALE WARNING UNTIL 2 PM EDT SUNDAY FOR ANZ430-431-452>455. STORM WARNING UNTIL 7 AM EDT SUNDAY FOR ANZ450-451. GALE WARNING FROM 7 AM TO 2 PM EDT SUNDAY FOR ANZ450-451. LOW WATER ADVISORY FROM 4 AM TO 10 AM EDT SUNDAY FOR ANZ430- 431. && $$ SYNOPSIS.../ MEOLA NEAR TERM.../ DELISI SHORT TERM...DELISI LONG TERM...MEOLA AVIATION.../ MARINE.../ HYDROLOGY... TIDES/COASTAL FLOODING.../ MPD de AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 735 PM EST SAT MAR 8 2008 .SYNOPSIS... AN AREA OF LOW PRESSURE OVER PENNSYLVANIA LATE THIS AFTERNOON WILL INTENSIFY AND LIFT NORTHEAST INTO MAINE BY DAYBREAK SUNDAY. HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST ON SUNDAY AND REMAIN INTO MONDAY. A WEAK SYSTEM WILL MOVE ACROSS THE AREA MONDAY NIGHT. ANOTHER WEAK SYSTEM WILL MOVE ACROSS THE AREA ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... WHAT SEEMS TO BE A PENULTIMATE LINE OF CONVECTION WAS READY TO MOVE OUT OF NORTHERN NEW JERSEY AT 615 PM EST. THE LAST OF THE CONVECTION ASSOCIATED WITH THE SURFACE SYSTEM WAS LIFTING INTO NORTHERN NEW JERSEY AT 615 PM. IT WAS MIXING DOWN SOME STRONG WIND GUSTS AS IT LIFTED NORTHEAST. WE ARE CARRYING SCATTERED SHOWERS OR THUNDERSTORMS NORTH AND CENTRAL THIS EVENING. CYCLONIC FLOW AT THE SURFACE AND THE MID LEVEL TROF AXIS LINGER FOR A WHILE ONCE THE COLD FRONT IS THROUGH AND THE SURFACE LOW IS WELL NORTH OF US, SO WE MAINTAIN A CHANCE OF RAIN OR SNOW SHOWERS IN THE NORTHWEST FOR A LONGER TIME TONIGHT THAN ELSEWHERE. ACKNOWLEDGING THAT THERE WILL BE FLOODING FOR A WHILE AFTER THE BULK OF THE RAIN, WE`VE ALLOWED THE FLOOD WATCH TO EXPIRE AT 6 PM AND WILL HANDLE FLOODING WITH WARNINGS, ADVISORIES AND STATEMENTS. THE WEATHER STORY WAS TRANSITIONING TO THE WIND. MODELS SHOW H8 WINDS AT OR ABOVE 50 KT BY 00Z AND CONTINUING THROUGH 06Z, WITH VERY SIGNIFICANT PRESSURE RISES SWEEPING ACROSS THE AREA NEAR AND NORTHWEST OF THE INTERSTATE 95 CORRIDOR. STRONG NVA ACCOMPANIES A JET AT H5 IN EXCESS OF 100 KTS, AND THAT JET RUNS ALONG THE EAST SIDE OF A NEGATIVE TILT TROF AXIS EMANATING FROM THE H5 CUTOFF. THIS, ACCORDING TO AN IN-HOUSE DECISION TREE, SPELLS WIND GUSTS AT OR ABOVE 50 KT. THE BUFKIT SOUNDINGS SUPPORT GUSTS TO AROUND 45 KT IN THE SAME AREA, AND WE`VE DECIDED TO GO WITH A HIGH WIND WARNING FOR THE AREA IN QUESTION AND A WIND ADVISORY SOUTHEAST OF THERE. WINDS SHOULD BEGIN TO DIMINISH DURING THE PRE-DAWN HOURS. WE HAVEN`T DEVIATED TOO MUCH FROM THE PREVIOUS FORECAST REGARDING TEMPERATURES, AS THAT DOESN`T SEEM TO BE WHERE THE BULK OF THE ACTION IS IN THE FIRST PERIOD. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... FRANKLY, THE BULK OF THE ACTION IS IN THE NEAR TERM. WINDS WILL DIMINISH GRADUALLY DURING THE DAY ON SUNDAY, AS A SURFACE HIGH PRESSURE RIDGE WILL DRIFT ACROSS THE AREA SUNDAY NIGHT AND EARLY MONDAY. A CONSIDERABLY WEAKER MID LEVEL IMPULSE WILL MOVE TOWARD US MONDAY AND CROSS THE AREA MONDAY NIGHT. WE HAVE PUT IN SOME CHANCE POPS FOR THE SOUTHERN ZONES ON MONDAY NIGHT, BUT THE AMOUNT OF PRECIPITATION EXPECTED IS VIRTUALLY NIL. WE`VE STAYED CLOSE TO A COMBINATION OF GUIDANCE AND CONTINUITY ON TEMPERATURES THROUGH THE PERIOD. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THE FORECAST LOOKS RELATIVELY DRY THROUGH THE MAJORITY OF THE EXTENDED PERIOD. THE PERIOD STARTS OFF WITH HIGH PRESSURE OFF TO THE SOUTHWEST. THIS HIGH STAYS JUST TO THE SOUTHWEST OF THE REGION WEDNESDAY AS A WEAK TROUGH MOVES ACROSS THE AREA. THIS TROUGH COULD BRING SOME LIGHT SHOWERS ON WEDNESDAY, MAINLY JUST TO THE POCONOS AND LEHIGH VALLEY, BUT NOTHING SIGNIFICANT IS EXPECTED AT THIS TIME. A BRIEF PERIOD OF HIGH PRESSURE WILL FOLLOW FOR THURSDAY AND THURSDAY NIGHT. THE NEXT WEATHER MAKER LOOKS TO BE AT THE END OF THE WORK WEEK AS A TROUGH APPROACHES THE REGION FROM THE WEST. A LOW PRESSURE SYSTEM LOCATED OVER NORTHEASTERN CANADA, WILL TRY TO DRAG A COLD FRONT ACROSS THE REGION EARLY FRIDAY. HOWEVER, ANOTHER LOW OVER THE MISSISSIPPI VALLEY WILL MAKE ITS WAY NORTHEAST AND PASS RIGHT OVER THE REGION LATE FRIDAY INTO SATURDAY. FOLLOWED ALONG THE LINES OF HPC FOR THE MOST PART BUT DID MAKE OCCASIONAL ADJUSTMENTS BASED ON MOS GUIDANCE. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... SHOWERS AND THUNDERSTORMS HAD EXITED THE AREA AND TAF SITES HAD RETURNED MOSTLY TO VFR (KABE HAD A MARGINAL VFR CEILING), WITH JUST A COUPLE OF LIGHT LEFTOVER ECHOES ON RADAR. NOW, STRONG WINDS AND WIND GUSTS WILL BE THE STORY FOR THE NEXT 36 HOURS OR SO. THE RUC WAS QUITE GOOD IN DEPICTING STRONG DEVELOPMENT OF WINDS (AND, IN RETROSPECT, THUNDERSTORM DEVELOPMENT) BETWEEN 22Z AND 23Z. WINDS WILL BE QUITE STRONG, WITH GUSTS REACHING 40 TO 50 KNOTS EARLY TONIGHT, AND PERHAPS SLACKING OFF A BIT LATER TONIGHT AND A BIT MORE SUNDAY, BEFORE REALLY DROPPING OFF LATER SUNDAY AFTERNOON AS THE GRADIENT MOVES OUT OF THE AREA AND HIGH PRESSURE BRIEFLY BUILDS INTO THE REGION. BEYOND THE TAF PERIOD, THERE ARE SEVERAL WEAK SYSTEMS THAT ARE FORECAST TO MOVE THROUGH THE AREA. ONE BEING ON MONDAY, ANOTHER ON WEDNESDAY, AND ANOTHER BEING NEXT FRIDAY. THE SYSTEM NEXT FRIDAY WILL LIKELY HAVE THE GREATEST IMPACT, ALTHOUGH THE FIRST TWO COULD PRODUCE SOME SHOWER ACTIVITY ACROSS THE AREA. && .MARINE... A COLD FRONT WILL MOVE ACROSS THE WATERS TONIGHT, WITH A STRONG WEST TO NORTHWEST FLOW BEHIND IT. WE HAVE CONTINUED THE GALE WARNING FOR THE DELAWARE BAY AND COASTAL WATERS SOUTH OF LITTLE EGG INLET. NORTH OF LITTLE EGG INLET, WE HAVE ISSUED A STORM WARNING FOR THE OVERNIGHT HOURS AS THERE MAY BE A PERIOD OF STORM FORCE WINDS IN THE NORTHERN SECTIONS OVERNIGHT TONIGHT. THESE WINDS SHOULD BEGIN TO DIMINISH TOWARD DAYBREAK TOMORROW, BUT EVERYONE SHOULD STILL EXPERIENCE GALES THROUGH THE MORNING SUNDAY. BY SUNDAY AFTERNOON, WINDS SHOULD DIMINISH TO SMALL CRAFT CRITERIA AND WILL LIKELY LAST THROUGH SUNDAY EVENING. SMALL CRAFT CRITERIA ARE NOT EXPECTED THROUGH THE REST OF THE FORECAST PERIOD, ALTHOUGH THERE ARE A COUPLE OF WEAK SYSTEMS THAT MAY MOVE THROUGH THE AREA MONDAY OR WEDNESDAY. THEY SHOULD NOT CAUSE ANY PROBLEMS HOWEVER. && .HYDROLOGY... THE FLOOD WATCH HAS EXPIRED, AND ALL SUBSEQUENT FLOODING CONCERNS FROM THIS SYSTEM WILL BE HANDLED BY WARNINGS, ADVISORIES AND STATEMENTS. && .TIDES/COASTAL FLOODING... TIDE HEIGHTS AT CAMBRIDGE JUST REACHED FLOOD LEVEL EARLY THIS EVENING, AND THEY DID SO ABOUT 90 MINUTES AFTER ASTRONOMICAL HIGH TIDE THANKS TO THE STRONG WEST-SOUTHWEST FLOW. THE WINDS MAY VEER ENOUGH TO MAKE THIS ISOLATED IN NATURE OVER THE NEXT FEW HOURS, BUT TO ERR ON THE CAUTIOUS SIDE WE ISSUED A STATEMENT ABOUT MINOR TIDAL FLOODING FOR THE NORTHERN MARYLAND EASTERN SHORE. A LOW WATER ADVISORY HAS BEEN ISSUED FOR THE COASTAL WATERS AND DELAWARE BAY FOR THE LOW TIDE CYCLE SUNDAY MORNING. WITH THE STRONG WEST TO NORTHWEST WINDS, BLOW-OUT TIDES ARE EXPECTED. PLEASE REFER TO THE LATEST MARINE WEATHER STATEMENT FOR DETAILS. THE LOW TIDE ON SUNDAY NIGHT COULD POSSIBLY REACH BLOW- OUT CONDITIONS AGAIN, SO WE WILL NEED TO CONTINUE TO MONITOR THE FORECAST FOR FUTURE UPDATES. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...HIGH WIND WARNING UNTIL 5 AM EDT SUNDAY FOR PAZ054-055-060>062- 067>071. NJ...HIGH WIND WARNING UNTIL 5 AM EDT SUNDAY FOR NJZ001-007>010- 012>020-026-027. WIND ADVISORY UNTIL 5 AM EDT SUNDAY FOR NJZ021>025. DE...HIGH WIND WARNING UNTIL 5 AM EDT SUNDAY FOR DEZ001. WIND ADVISORY UNTIL 5 AM EDT SUNDAY FOR DEZ002>004. MD...HIGH WIND WARNING UNTIL 5 AM EDT SUNDAY FOR MDZ008. WIND ADVISORY UNTIL 5 AM EDT SUNDAY FOR MDZ012-015-019-020. MARINE...LOW WATER ADVISORY FROM MIDNIGHT EST TONIGHT TO 7 AM EDT SUNDAY FOR ANZ450>455. GALE WARNING UNTIL 2 PM EDT SUNDAY FOR ANZ430-431-452>455. STORM WARNING UNTIL 7 AM EDT SUNDAY FOR ANZ450-451. GALE WARNING FROM 7 AM TO 2 PM EDT SUNDAY FOR ANZ450-451. LOW WATER ADVISORY FROM 4 AM TO 10 AM EDT SUNDAY FOR ANZ430- 431. && $$ SYNOPSIS...MEOLA NEAR TERM...DELISI SHORT TERM...DELISI LONG TERM...MEOLA AVIATION.../ LR MARINE...LR HYDROLOGY...DELISI TIDES/COASTAL FLOODING...ROBERTSON/DELISI de AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE ID 852 AM MST SAT MAR 8 2008 .DISCUSSION...PCPN FADING AS MAIN ENERGY ALOFT TURNS SSEWD INTO NEVADA AND WEAKENS THE SURFACE COLD FRONT IN SCENTRAL IDAHO. 15Z SAPIX SHOWED ENHANCED HIGHER CLOUDS FURTHER EAST IN WRN WY AND ALONG THE UT/CO BORDER BUT THE PCPN WAS IN THE UN-ENHANCED CLOUDS IN SRN IDAHO/NERN NEVADA. AMOUNTS HAVE BEEN LESS THAN .10 INCH SO FAR AND EVEN LESS THAN THAT IS EXPECTED THE REST OF TODAY... MOST OF IT OCCURRING IN THE SW IDAHO HIGHLANDS AND SRN TWIN FALLS COUNTY. OREGON ZONES ARE ALREADY DRYING AS NEXT PACIFIC UPPER RIDGE COMES IN. FOG WILL LIKELY DEVELOP IN OUR NRN CWA VALLEYS OVERNIGHT AS LOWER LEVELS REMAIN MOIST. MOSTLY SUNNY AND MILDER SUNDAY AS UPPER RIDGE COMES OVER CWA. NO MORE PCPN UNTIL LATE MONDAY NIGHT. CURRENT FORECAST LOOKS ABOUT RIGHT...NO UPDATES. && .AVIATION...WEAK SURFACE COLD FRONT CONTINUES TO MOVE EAST OVER THE FORECAST AREA. PRECIPITATION HAS ENDED OVER SOUTHEAST OREGON BUT WILL CONTINUE TO SEE LOCAL MVFR AND ISOLATED IFR CONDITIONS AND MOUNTAIN OBSCURATION THIS MORNING OVER SOUTHWEST IDAHO. CONDITIONS HAVE IMPROVED FROM THE WEST OVER SOUTHEAST OREGON AND WILL CONTINUE TO MOVE TO THE WEST THIS AFTERNOON. EXPECT MOSTLY CLEAR SKIES AND VFR CONDITIONS BY THIS EVENING. SURFACE WINDS TODAY WILL BE LIGHT TO MODERATE FROM THE WEST TO NORTHWEST WITH MODERATE WEST TO NORTHWEST WINDS ALOFT. && .PREV DISCUSSION... SHORT TERM...TODAY THROUGH SUNDAY...COLD FRONT AT 3 AM EXTENDED FROM THE HELLS CANYON AREA THROUGH THE LOWER TREASURE VALLEY WHERE A TRACE OF RAIN HAD FALLEN AT ONTARIO. BURNS HAD CHANGED OVER TO SNOW CLOSER TO THE COOL DEVELOPING UPPER LOW. THE H4 TROUGH AND VORTICITY CENTER WHICH HAVE BEEN MOVING INLAND/EAST EARLY THIS SATURDAY MORNING LINE UP WELL WITH THE WATERVAPOR IMAGERY OVER OREGON AND RUC ANALYSES. THE TROUGH IS EXPECTED TO TURN SOUTHEAST BY 6 AM AS THE RIDGE TO ITS WEST AMPLIFIES - IN FACT JET ENERGY HAD FINALLY TURNED FROM WESTERLY TO NW OVER CALIFORNIA AS OF 3 AM BLASTING HIGH CLOUDS SOUTHEASTWARD. THE RUC CUTS OFF THE H4 LOW OVER JORDAN VALLEY /WITH THE BEST PRECIP/ BY 8 AM AND DIGS IT SE INTO NE NV BY 2 PM TAKING NUMEROUS RAIN SHOWERS /SNOW ABOVE 5K FT/ INTO THE SOUTHERN MOUNTAINS. HAVE KEPT NUMEROUS SHOWERS IN THE OROGRAPHICALLY FAVORED WEST CENTRAL/BOISE MOUNTAINS THIS MORNING AS WELL. DRY AIR ACROSS THE UPPER TREASURE VALLEY EXPECTED TO KEEP POPS LIMITED TO SCATTERED TODAY. HIGH PRESSURE BUILDS IN WITH DRYING NORTH FLOW ALOFT THIS AFTERNOON THEN THE DRY SURFACE HIGH CENTER BUILDS OVER SW IDAHO TONIGHT. WITH IT - CLEAR SKIES WILL ALLOW STRONG RADIATIONAL COOLING AND HAVE CUT MOS TEMPERATURES SLIGHTLY. ALSO HAVE LEFT PATCHY FOG IN THE FORECAST IN MOST MOIST /MAXRH- WISE/ AREAS. THE HIGH RETREATS SUNDAY AS THE NEXT SYSTEM /OUT AT THE DATELINE AT 3 AM THIS MORNING/ SLOWLY APPROACHES...FOR A SUNNY DAY WITH ABOVE NORMAL TEMPERATURES TO START THE SWITCH TO DAYLIGHT TIME...ALTHOUGH EXPECT INCREASING SE TO SW WINDS BY AFTERNOON. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...ACTIVE PATTERN TO CONTINUE THROUGH NEXT WEEK. SHORTWAVE RIDGE BUILDS OVER THE INTERMOUNTAIN WEST ON MONDAY IN RESPONSE TO A DEEPENING LOW OFF OF THE NORTH PACIFIC COAST. THIS WILL BRING A BRIEF PERIOD OF WARMER AND DRIER CONDITIONS ON MONDAY. BREEZY SOUTHEAST WINDS MONDAY WILL ALLOW HIGH TEMPERATURES TO CLIMB 4 TO 6 DEGREES ABOVE NORMAL. A WARM FRONT WILL MOVE ACROSS THE CWA EARLY TUESDAY MORNING...KEEPING LOWS ON THE MILD SIDE...FOLLOWED BY A COLD FRONT DURING THE DAY ON TUESDAY. PRECIPITATION WILL MAINLY BE FOCUSED ALONG THE COLD FRONT DURING THE DAY TUESDAY...AS MUCH OF THE DYNAMICS/MOISTURE WILL BE FURTHER NORTH OFF THE WASHINGTON STATE COAST. UPPER TROUGH SHIFTS SOUTHEAST ACROSS THE INTERMOUNTAIN WEST TUESDAY AFTERNOON INTO EARLY WEDNESDAY. THE TROUGH WILL PROVIDE ENOUGH INSTABILITY AND UPPER DYNAMICS...WITH EXIT REGION OF 300 MB JET OVER ID/NV BORDER FOR CONVECTIVE SHOWERS. ANOTHER BREAK IN THE PRECIPITATION WEDNESDAY AS UPPER RIDGE BUILDS ACROSS THE AREA IN RESPONSE TO ANOTHER SERIES OF SYSTEMS FOR THURSDAY AND FRIDAY. THESE SYSTEM ARE ASSOCIATED WITH A BROAD LONGWAVE TROUGH FROM THE NORTHERN PACIFIC WHICH IS FORECAST TO SETTLE OVER THE WESTERN U.S. FRIDAY. TEMPERATURES THROUGH THE PERIOD WILL BE AROUND NORMAL. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...NONE. OR...NONE. && $$ WEATHER.GOV/BOISE DISCUSSION...LC AVIATION.....JA PREV SHORT TERM...VM PREV LONG TERM....JS id AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE ID 356 AM MST SAT MAR 8 2008 .SHORT TERM...TODAY THROUGH SUNDAY...COLD FRONT AT 3 AM EXTENDED FROM THE HELLS CANYON AREA THROUGH THE LOWER TREASURE VALLEY WHERE A TRACE OF RAIN HAD FALLEN AT ONTARIO. BURNS HAD CHANGED OVER TO SNOW CLOSER TO THE COOL DEVELOPING UPPER LOW. THE H4 TROUGH AND VORTICITY CENTER WHICH HAVE BEEN MOVING INLAND/EAST EARLY THIS SATURDAY MORNING LINE UP WELL WITH THE WATERVAPOR IMAGERY OVER OREGON AND RUC ANALYSES. THE TROUGH IS EXPECTED TO TURN SOUTHEAST BY 6 AM AS THE RIDGE TO ITS WEST AMPLIFIES - IN FACT JET ENERGY HAD FINALLY TURNED FROM WESTERLY TO NW OVER CALIFORNIA AS OF 3 AM BLASTING HIGH CLOUDS SOUTHEASTWARD. THE RUC CUTS OFF THE H4 LOW OVER JORDAN VALLEY /WITH THE BEST PRECIP/ BY 8 AM AND DIGS IT SE INTO NE NV BY 2 PM TAKING NUMEROUS TO RAIN SHWOERS /SNOW ABOVE 5K FT/ INTO THE SOUTHERN MOUNTAINS. HAVE KEPT NUMEROUS SHOWERS IN THE OROGRAPHICALLY FAVORED WEST CENTRAL/BOISE MOUNTAINS THIS MORNING AS WELL. DRY AIR ACROSS THE UPPER TREASURE VALLEY EXPECTED TO KEEP POPS LIMITED TO SCATTERED TODAY. HIGH PRESSURE BUILDS IN WITH DRYING NORTH FLOW ALOFT THIS AFTERNOON THEN THE DRY SURFACE HIGH CENTER BUILDS OVER SW IDAHO TONIGHT. WITH IT - CLEAR SKIES WILL ALLOW STRONG RADIATIONAL COOLING AND HAVE CUT MOS TEMPERATURES SLIGHTLY. ALSO HAVE LEFT PATCHY FOG IN THE FORECAST IN MOST MOIST /MAXRH- WISE/ AREAS. THE HIGH RETREATS SUNDAY AS THE NEXT SYSTEM /OUT AT THE DATELINE AT 3 AM THIS MORNING/ SLOWLY APPROACHES...FOR A SUNNY DAY WITH ABOVE NORMAL TEMPERATURES TO START THE SWITCH TO DAYLIGHT TIME...ALTHOUGH EXPECT INCREASING SE TO SW WINDS BY AFTERNOON. .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...ACTIVE PATTERN TO CONTINUE THROUGH NEXT WEEK. SHORTWAVE RIDGE BUILDS OVER THE INTERMOUNTAIN WEST ON MONDAY IN RESPONSE TO A DEEPENING LOW OFF OF THE NORTH PACIFIC COAST. THIS WILL BRING A BRIEF PERIOD OF WARMER AND DRIER CONDITIONS ON MONDAY. BREEZY SOUTHEAST WINDS MONDAY WILL ALLOW HIGH TEMPERATURES TO CLIMB 4 TO 6 DEGREES ABOVE NORMAL. A WARM FRONT WILL MOVE ACROSS THE CWA EARLY TUESDAY MORNING...KEEPING LOWS ON THE MILD SIDE...FOLLOWED BY A COLD FRONT DURING THE DAY ON TUESDAY. PRECIPITATION WILL MAINLY BE FOCUSED ALONG THE COLD FRONT DURING THE DAY TUESDAY...AS MUCH OF THE DYNAMICS/MOISTURE WILL BE FURTHER NORTH OFF THE WASHINGTON STATE COAST. UPPER TROUGH SHIFTS SOUTHEAST ACROSS THE INTERMOUNTAIN WEST TUESDAY AFTERNOON INTO EARLY WEDNESDAY. THE TROUGH WILL PROVIDE ENOUGH INSTABILITY AND UPPER DYNAMICS...WITH EXIT REGION OF 300 MB JET OVER ID/NV BORDER FOR CONVECTIVE SHOWERS. ANOTHER BREAK IN THE PRECIPITATION WEDNESDAY AS UPPER RIDGE BUILDS ACROSS THE AREA IN RESPONSE TO ANOTHER SERIES OF SYSTEMS FOR THURSDAY AND FRIDAY. THESE SYSTEM ARE ASSOCIATED WITH A BROAD LONGWAVE TROUGH FROM THE NORTHERN PACIFIC WHICH IS FORECAST TO SETTLE OVER THE WESTERN U.S. FRIDAY. TEMPERATURES THROUGH THE PERIOD WILL BE AROUND NORMAL. && .AVIATION...MOSTLY VFR CONDITIONS WITH MOUNTAIN OBSCURATION WITH COLD FRONTAL PASSAGE THIS MORNING ACROSS SE OREGON. AS THIS MOIST SYSTEM CONTINUES ACROSS THE INTERMOUNTAIN WEST TODAY...EXPECT ISOLATED MVFR AND LOCAL IFR CONDITIONS IN RAIN AND SNOW SHOWERS MAINLY IN THE MOUNTAINS. THE TREASURE AND MAGIC VALLEYS AS WELL AS LOWER ELEVATIONS OF SOUTHEAST OREGON WILL REMAIN MOSTLY VFR. CONDITIONS WILL IMPROVE FROM THE WEST AFTER 18Z SATURDAY WITH SKIES CLEAR FOR VFR. SURFACE WINDS WILL BE MODERATE WEST TO NORTHWEST THROUGH SATURDAY AFTERNOON DIMINISHING BY EVENING. WINDS ALOFT WILL BE MODERATE WEST TO NORTHWEST. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...NONE. OR...NONE. && $$ WEATHER.GOV/BOISE SHORT TERM...VM LONG TERM....JS AVIATION.....JS id AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1158 AM CST SAT MAR 8 2008 .DISCUSSION... ISSUED 1021 AM CST SAT MAR 8 2008 WINDS ACROSS THE AREA WILL SLOWLY DIMINISH AND BACK AROUND TO THE NORTHWEST TODAY AS STRONG STORM SYSTEM OVER THE OHIO VALLEY RETREATS... AND NARROW RIDGE OF HIGH PRESSURE BUILDS IN FROM THE WEST. HOWEVER... 12Z ILX RAOB INDICATES SHALLOW MOIST LAYER STILL EXISTS BETWEEN 2-4K FEET... AND VISIBLE SATELLITE SHOWS CU POPPING UP AGAIN IN THIS MOIST AREA... WHICH THE NAM AND RUC SEEM TO BE HANDLING PRETTY WELL. ALSO... PROFILER OBS SUGGEST STILL GETTING A FETCH OFF LAKE MICHIGAN WHICH IS HELPING TO ENHANCE CLOUD COVER EAST OF THE I-57 CORRIDOR... DNV AWOS EVEN REPORTED A FEW FLURRIES NOT TOO LONG AGO. AS LOW LEVEL WINDS CONTINUE TO BACK...DRIER AIR WILL MOVE INTO THE AREA. THIS COMBINED WITH DIURNAL MIXING SHOULD ALLOW CLOUDS TO DECREASE EARLY THIS AFTERNOON ACROSS THE I-55 CORRIDOR. HOWEVER... NAM/RUC AND LOCAL WRF SUGGEST ELEVATED MOIST LAYER WILL KEEP SOME CLOUDS AROUND THE FAR NORTHEAST THROUGH LATE AFTERNOON. WILL EDIT GRIDS TO REFLECT SHORT TERM FORECAST EVOLUTION... AND SHOULD HAVE PFM OUT BEFORE 11 AM. WILL REISSUE ZFP TO INCREASE SKY COVER ACROSS THE FAR EAST. HARDIMAN && .AVIATION... ISSUED 1155 AM CST SAT MAR 8 2008 SHALLOW MOIST LAYER LEFT OVER FROM YESTERDAY CAUSING CU TO FLARE UP AGAIN ACROSS MOST TERMINALS. CIGS SHOULD MIX UP TO VFR BETWEEN 18Z-20Z FOR ALL TERMINALS EXCEPT CMI. LOW LEVEL WIND PROFILERS SUGGEST WE ARE STILL SEEING A COMPONENT OFF LAKE MICHIGAN AT CMI... AND THIS IS ENHANCING CU DEVELOPMENT... AND KEEPING CIGS BETWEEN 020-030 THROUGH THIS AFTERNOON. A FEW REPORTS OF 7SM WITH FLURRIES HAVE ALSO BEEN NOTED IN THE AREA... BUT RISK/IMPACTS LOW EVEN IF A FEW FLAKES FELL AT CMI...SO NOT WORTH MENTIONING IN TAF. BACKING WINDS SHOULD PULL LOWER CLOUDS OUT OF CMI THIS EVENING... ALONG WITH DIURNAL DECREASE IN COVERAGE. MID-LEVEL CLOUDS WILL THICKEN FROM WEST TO EAST AHEAD OF WEAK CLIPPER WHICH WILL APPROACH THE AREA BY MORNING WITH LITTLE IN THE WAY OF IMPACTS OUTSIDE OF MID-LEVEL CLOUDS AND SHIFTING WINDS. HARDIMAN && .PREV DISCUSSION... ISSUED 310 AM CST SAT MAR 8 2008 SURFACE LOW PRESSURE SYSTEM SLOWLY MAKING ITS WAY UP THE ERN SEABOARD THIS MORNING. PERSISTENT CLOUD COVER OVER THE FAR SE REMAINING IN PLACE ON SATELLITE IMAGERY...THOUGH THE ASSOCIATED PRECIP WAS SLOWLY ERODED BACK IN THE OVERNIGHT HOURS. WINDS COMING AROUND TO MORE NWRLY THIS MORNING...AND SHOULD ASSIST IN KEEPING THE TEMPERATURES AROUND AND JUST BELOW YESTERDAYS HIGHS...DESPITE THE AMPLE SUNSHINE IN THE MORNING. MODELS DIFFERING HERE AND THERE AS THE FLOW WEAKENS SOMEWHAT ON THE OTHER SIDE OF THE WEEKEND...ALMOST SPLITTING FROM TIME TO TIME WITH CENTRAL ILLINOIS CAUGHT BTWN TWO TRACKS OF UPPER LEVEL DISTURBANCES. GOING WITH AN ECMWF/GFS BLEND...KEEPING VERY CLOSE TO LAST FCST ISSUANCE. SHORT TERM...TODAY AND TOMORROW... LITTLE IN THE WAY OF CLOUDS AS LOW CONTINUES TO SLOWLY PULL THE CLOUDS IN THE SE ALONG WITH IT OUT TO THE EAST. LITTLE IN THE WAY OF MOISTURE ON WV SATELLITE THIS MORNING TO THE NW. WHAT IS THERE WILL NOT ARRIVE IN CENTRAL ILLINOIS UNTIL LATER IN THE AFTERNOON...EVEN THEN SHOULD BE CONFINED TO MID LEVEL CLOUDS AT LEAST UNTIL THE OVERNIGHT HOURS AHEAD OF THE NEXT SYSTEM. DISTURBANCE IN S CENTRAL CANADA THIS MORNING ON TRACK TO DIVE INTO THE REGION TONIGHT...AND PASS ACROSS THE NRN TIER OF THE STATE SUNDAY. CHANCE POPS WARRANTED FOR I-74 CORRIDOR NWD. TRACK OF THE DISTURBANCE IS A BIT OF A QUESTION MARK AS THE WAVE PATTERN IS SPLITTING WITH THIS PULSE IN MOST OF THE MODELS. CHANCE POPS MAY BE SPREAD SWD WITH NEXT ISSUANCES AS A RESULT. LONG TERM...MONDAY THROUGH WEDNESDAY... GENERAL WARMING TREND THROUGH THE FIRST HALF OF THE WEEK AS HIGH PRESSURE TAKES OVER AT THE SFC. FORECAST REMAINS DRY...AT LEAST UNTIL WEDNESDAY NIGHT AND INTO THURSDAY AS A COLD FRONT BTWN TWO LOWS MOVES ACROSS THE CONUS. BEST DYNAMICS APPEAR TO REMAIN ALONG THE GULF COAST...BRINGING RAIN TO ILX. WILL HAVE TO KEEP AN EYE OUT FOR THUNDER CHANCES IN NEXT FEW RUNS. HJS && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 1112 PM CST FRI MAR 7 2008 .DISCUSSION... 822 PM CST NO MAJOR CHANGES PLANNED TO GOING FORECAST FOR TONIGHT...THOUGH WORKING TO MASSAGE GRIDS SOME TO SHIFT HEAVIER QPF/SNOW AND HIGHER POPS A BIT FARTHER EAST/SOUTHEAST. LAKE EFFECT FLURRIES AND LIGHT SNOW SHOWERS CONTINUE OFF SOUTHERN PORTIONS OF THE LAKE INTO THE CITY AND SE SUBURBS AS WELL AS NW IN. INCREASINGLY COLDER AIR SPREADING SOUTHWARD HAS ALREADY STEEPENED UP LOW LEVEL LAPSE RATES OVER THE LAKE AND RESULTED IN AN INCREASE IN THE ORGANIZATION/INTENSITY OF THE LAKE EFFECT SNOW OVER NORTHERN PORTIONS OF LAKE MICHIGAN AND EASTERN LAKE SUPERIOR NOTED BY THE TREND FOR COOLING CLOUD TOPS OVER THE PAST FEW HOURS. ALREADY SEEING THE COOLING CLOUD TOPS WORKING SOUTH DOWN THE LAKE WHICH SUPPORTS THE LATEST SUITE OF NUMERICAL GUIDANCE WHICH GETS THE LAKE EFFECT REALLY CRANKING LATE THIS EVENING AND OVERNIGHT. BIGGEST SHORT TERM FORECAST CHALLENGE REMAINS DETERMINING WHERE THE LAKE EFFECT BAND WILL EVENTUALLY BECOME QUASI-STATIONARY OVERNIGHT INTO EARLY SATURDAY MORNING. LOCALLY RUN WRF-ARW IS THE ROGUE MODEL AT THIS POINT SUGGESTING THAT THE LAKE EFFECT BAND WILL SET UP OVER LAKE COUNTY IL SOUTHWARD INTO COOK COUNTY. THE 18Z WRF-NMM IS SIMILAR TO ITS 18Z AND 00Z RUNS YESTERDAY...AND ALSO IN AGREEMENT WITH THE LATEST HI-RES RUC WHICH SUGGESTS THE ORGANIZED LAKE BAND WILL SET UP LARGELY PARALLEL TO THE SHORE AND JUST OFF SHORE...MAKING LANDFALL IN NORTHERN COOK COUNTY AND STRETCHING THROUGH EASTERN COOK INTO EASTERN WILL COUNTY AND CLIPPING WESTERN PORTIONS OF LAKE COUNTY IN. REALLY ONLY TALKING A DIFFERENCE OF 15-25 MILES...WHICH IS REALLY PROBABLY NOT MUCH ABOVE THE NOISE LEVEL WHEN IT COMES TO MODELING. WHERE EVER THE BAND SETS UP...EXPECT IT TO SHIFT SLOWLY WESTWARD FOR A TIME LATE TONIGHT BEFORE WINDS BEGIN TO VEER AND IT STARTS AN EVENTUAL MIGRATION EAST FOCUSING MORE IN INDIANA BY SAT AFTERNOON. STILL APPEARS AS THOUGH THE LAKE EFFECT WILL BE MOST ORGANIZED AND HEAVIEST FROM 06 OR 08Z THROUGH ABOUT 15Z SATURDAY MORNING BEFORE SLOWLY WEAKENING. GOING SNOWFALL AMOUNTS LOOK RIGHT ON TARGET WITH SOME LOCATIONS LIKELY ENDING UP WITH 3-6 INCHES BY THE TIME THE SNOW ENDS SATURDAY AFTERNOON OR EVENING. STILL CANT COMPLETELY RULE OUT ISOLATED AMOUNTS OVER 6 INCHES SHOULD THE BAND SIT IN PLACE TOO LONG...WHILE OTHER PORTIONS OF COOK AND LAKE COUNTIES LIKELY END UP WITH JUST FLURRIES. MIDNIGHT SHIFT WILL NEED TO WATCH HOW THE BAND BEHAVES TONIGHT...WITH IT POSSIBLE THAT THE LAKE EFFECT SNOW ADVISORY MAY NEED TO BE EXPANDED TO INCLUDE LAKE COUNTY INDIANA. WOULD LIKE TO SEE THE WHITES OF THE LAKE EFFECTS EYES BEFORE MAKING ANY CHANGES LIKE THAT. IZZI && .AVIATION... 1111 PM CST RE 06Z TAFORS...LIGHT LAKE EFFECT SNOW CONTINUES ACROSS FAR SE WI...NE IL...NW IN AT LATE EVENING. IR SATELLITE INDICATING AN INCREASINGLY WELL DEFINED BAND FROM NORTHERN LAKE MI S ALONG THE SE WI SHORELINE AND INTO NE IL. KMKX 88D ALSO BEGINNING TO DETECT A DOUBLE BAND OVER THE LAKE AS THE COLD AIR DEEPENS AND DEPTH OF LAKE EFFECT INCREASES ENOUGH TO BE PICKED UP BY 0.5 DEG SLICE. PROBLEM IS WHERE THE TAIL END OF THE NARROW LES BAND WILL RESIDE OVER THE FORECAST PERIOD. MODELS STILL MAINTAIN BAND ALONG THE WI SHORE AND INLAND S ACROSS COOK CO. VARIATIONS ON JUST HOW FAR INLAND WILL GET BUT CONSENSUS OF MODELS IS WILL MAINLY RESIDE ACROSS KMDW WITH KORD ON THE EDGE OF BAND. HAVE MVFR CIGS AND VSBYS THRU 12Z AT KORD AND 14Z AT KMDW WITH TEMPO IFR FOR KMDW AS EXPECTED TO BE UNDER MAIN LAKE EFFECT PLUME. MODELS INDICATE THAT LES WILL SHIFT TO THE E OUT OVER THE LAKE AS LOW LEVEL FLOW BACKS TO NNW-NW. TRS && .MARINE... 159 PM CST HIGH PRESSURE 30.6 INCHES WAS OVER NORTHERN MINNESOTA THIS AFTERNOON. THIS HIGH WILL MOVE EAST AND SPREAD FROM NORTHERN QUEBEC THROUGH WISCONSIN AND IOWA TO EASTERN TEXAS BY SATURDAY MORNING. A LOW WILL MOVE INTO NORTH DAKOTA WITH A PRESSURE OF 29.5 INCHES. AS THE HIGH MOVES EAST THE WIND OVER NORTHERN LAKE MICHIGAN WILL DECREASE IN SPEED. HOWEVER THE WIND WILL BE 10 TO 20 KNOTS ON THE SOUTH HALF OF LAKE MICHIGAN THROUGH SATURDAY. THE DIRECTION OF THE WIND WILL BE NORTH TO NORTHEAST THIS EVENING AND OVERNIGHT. THE FETCH OF THE WIND WILL PRODUCE SOME SIGNIFICANT WAVES ON THE SOUTH END OF THE LAKE. && .LOT WATCHES/WARNINGS/ADVISORIES... IL...LAKE EFFECT SNOW ADVISORY UNTIL 2 PM CST SATURDAY FOR ILZ006-014. IN...NONE. LM...SMALL CRAFT ADVISORY UNTIL 7 PM CST SATURDAY FOR LMZ740>745. && $$ il AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PADUCAH KY 1212 PM CDT SUN MAR 9 2008 .UPDATE... SENSIBLE WEATHER UPDATE FOR TODAY AND TONIGHT. && .DISCUSSION... COMPARED TO YESTERDAYS RUNS...THE CLOUD COVER IS MUCH SLOWER AND THINNER THAN EXPECTED. WITH THAT IN MIND...SLOWED THE SEWD PROGRESSION OF OPAQUE CLOUD COVER ACROSS THE WFO PAH FORECAST AREA FOR THE REMAINDER OF THIS AFTERNOON AND INTO THE EARLY EVENING. DUE TO AVERAGING TECHNIQUES...TEXT FORECASTS WILL STILL SHOW PARTLY CLOUDY/SUNNY FOR CLOUD TRENDS THIS AFTERNOON. WITH THE SHARPLY DIMINISHED SNOW COVER...EVEN THE TURBULENT MIXING ASSOCIATED WITH THE INCREASED WARM AIR ADVECTION IS RETARDING TIMELY DEVELOPMENT OF CUMULUS THIS AFTERNOON. DESPITE THE SNOW COVER...WARM AIR ADVECTION AND GOOD INSOLATION SHOULD HELP TEMPERATURES OVER SOUTHWESTERN INDIANA AND THE PENNYRILE REGION OF WEST KENTUCKY RECOVER INTO THE LOWER 40S...WITH 50S EXPECTED IN THE SNOW FREE AREAS OF SOUTHEAST MISSOURI...SOUTHERN ILLINOIS AND THE PURCHASE AREA OF WEST KENTUCKY. UTILIZED A BLEND OF SREF/NAM/RUC GUIDANCE FOR MAX TEMPERATURES TODAY...WITH A BLEND OF THE RUC/NAM FOR DEWPOINTS AND WINDS THIS AFTERNOON. && .PREV DISCUSSION... /ISSUED 316 AM CDT SUN MAR 9 2008/ DISCUSSION... MAIN FORECAST ISSUES ARE TEMPERATURES AND WEAK SYSTEM MOVING THROUGH SUNDAY NIGHT/MONDAY. TEMPERATURES TODAY WERE BASED ON SEVERAL PARAMETERS...THE LATEST VISIBLE SATELLITE IMAGE TO SEE WHERE SNOW WAS STILL ON THE GROUND...THE PREVIOUS FORECAST...AND A HEDGE TOWARD THE GFS MODEL. SOME OF THE MODEL GUIDANCE IS OUT TO LUNCH...CLEARLY MISSING THE FACT THERE IS SNOW ON THE GROUND. LATEST IR IMAGES AND TIME-HEIGHT CROSS SECTIONS SUGGEST THAT A MID LEVEL CLOUD DECK MAY ALSO PLAY A ROLE ACROSS THE AREA. A MAJORITY OF THE SNOW SHOULD MELT TODAY...BUT IN THE HEAVIER BANDS...THERE STILL MAY BE A LINGERING EFFECT ON MONDAY...SO WILL KEEP TEMPERATURES A BIT LOWER IN THE EAST. TEMPERATURE ADVECTION NOT VERY IMPRESSIVE AHEAD OR BEHIND THE SYSTEM ON MONDAY. SHORTWAVE OF CONCERN CURRENTLY OVER THE UPPER MIDWEST AND IS FORECAST TO REACH THE AREA JUST BEFORE 06Z MONDAY. THE NAM IS WEAKER AND A BIT SLOWER WITH THE SHORTWAVE. LEANED MORE TOWARD THE GFS FOR THIS PART OF THE FORECAST AS IT HAS BEEN A PERSISTENT SIGNAL. THE LATEST RUN HAS THIS SYSTEM A BIT STRONGER...BUT STILL WEAK. NOW RH INCREASES AS THE SYSTEM MOVES THROUGH. WILL THEREFORE BRING THE SLIGHT CHANCE DOWN TO THE TENNESSEE BORDER. BOTH MODELS HAVE THE SYSTEM OUT OF OUR AREA BY NOON MONDAY. WARM UP FINALLY GETS GOING IN EARNEST BY THE MIDDLE OF THE WEEK AS LOW PRESSURE DEVELOPS OUT OVER THE PLAINS AND SOUTHERLY WINDS INCREASE. WILL LIKELY SEE MEX MOS TEMPS IN THE 60S REALIZED WED AFTERNOON. NEXT COLD FRONT AND H50 TROF MOVE IN THU/THU EVENING AND BRING THE NEXT GOOD CHANCE OF SHOWERS WITH IT. RIGHT NOW...ECMWF AND GFS DIFFER ON HOW THE SFC PRESSURE FIELDS EVOLVE...WITH THE ECMWF HAVING MORE OF A CIRCULATION OVER NRN AL/MS WHILE THE GFS HAS MORE OF AN OPEN ELONGATED SFC TROF COMING THROUGH THU. WILL SPLIT THE DIFFERENCE FOR RIGHT NOW. ENOUGH INSTABILITY ALOFT ARRIVES THU AFTERNOON TO WARRANT SLIGHT CHC THUNDERSTORMS...BUT EVEN THE SHOWALTER INDICES STAY ABOVE 0 EXCEPT IN THE MO BOOTHEEL REGION. ALSO...NO APPRECIABLE CONVERGENCE PROGGED ALONG THE FRONT. THUS...SEVERE ASPECT OF THE SYSTEM LOOKS TO BE QUITE LOW AT THIS TIME. THE FRONT WILL SWEEP THROUGH THU NIGHT AND MAINLY SERVE TO BRING US BACK DOWN TO SEASONAL TEMPS FOR EARLY/MID MARCH. WILL STAY CLOSE TO MEX MOS TEMPS IN THE THU/FRI TIME FRAME. NO CHANGES MADE TO THE FORECAST BEYOND FRI. AVIATION... EXPECT VFR CONDITIONS MOST OF THE TAF PERIOD AS WEAK HIGH PRESSURE CONTINUES ACROSS THE REGION. MAY BE SOME VFR CEILINGS IN THE 5-10K FT RANGE...WITH S-SW WINDS 10 MPH DURING THE DAY. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...NONE. MO...NONE. IL...NONE. IN...NONE. && $$ SHORTL/LONG TERM....SMITH AVIATION...DH ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 406 PM CST SAT MAR 8 2008 .DISCUSSION... MAIN CHALLENGE IN THE VERY NEAR TERM IS DEALING WITH ANTICIPATED TEMPERATURE/DEWPOINT/CLOUD COVER ISSUES ASSOCIATED WITH THE DEPARTING UPPER LOW AND THE INITIAL WEAK WARM AIR ADVECTION IN ITS WAKE. FOR SPATIAL ORIENTATION...I UTILIZED THE 13KM RUC TO HANDLE THE ORIENTATION OF TEMPERATURES AND DEWPOINTS ASSOCIATED WITH THE SLOWLY DECAYING SNOW COVER TODAY. TEMPERATURES/DEWPOINTS HAVE BEEN SUPPRESSED 3-4 DEGREES BELOW GUIDANCE VALUES IN THE DEEPEST SNOW COVER OVER THE PENNYRILE REGION OF WEST KENTUCKY AND INTO SOUTHWEST INDIANA. I MAY BE TOO QUICK ON THE TEMPERATURE/DEWPOINT REBOUND OVER THE SAME AREA...BUT WITH STRONG MARCH SUN AND SLIGHTLY LONGER DAYLIGHT/ GIVEN DAYLIGHT SAVINGS TIME/...MAY A MORE RAPID REDUCTION IN THE SNOW COVER. I WAS MORE AGGRESSIVE WITH THE CLOUD COVER SUNDAY GIVEN THE INCREASED WARM AIR ADVECTION OVER THE COOL/MOIST BOUNDARY LAYER AND SHRINKING SNOW COVER FIELD...AS WELL AS WITH THE ANTICIPATED LIFT LATER IN THE DAY ASSOCIATED THE FORECAST CLIPPER SYSTEM MOVING THROUGH THE AREA SUNDAY NIGHT INTO EARLY MONDAY. THE GFS/NAM APPEAR TO BE MORE CONSISTENT WITH THIS CLIPPER IN LOCATION AND TIMING VS. THE ECMWF. THE SREF DOES SUGGEST SOME MEASURABLE PRECIPITATION WITH THIS CLIPPER...BUT IS FURTHER SOUTH AND WEST THAN THE NAM/GFS. ALL OF THE SHORT AND MEDIUM RANGE MODELS TAKE THE PROMINENT SHORTWAVE MOVING TOWARD NWRN CANADA AND DIVE IT SOUTHWARD TOWARD THE FOUR CORNERS REGION AND DAMPEN AND PHASE IT IN WITH THE PROGRESSIVE TROUGH ASSOCIATED WITH THE CLIPPER SYSTEM SUNDAY NIGHT INTO MONDAY. BEYOND MONDAY...ALL OF THE MEDIUM RANGE MODELS DEVELOP AND LOW AMPLITUDE RIDGE AND PUSH IT OVER THE WFO PAH FORECAST AREA BY WEDNESDAY...INCREASING THICKNESS AND OVERALL SURFACE TEMPERATURES 5 TO 10 DEGREES ABOVE NORMAL. THE ECMWF/GFS PHASE THE NEXT SHORTWAVE THROUGH THE MID/LOWER MS VALLEY WITH A CLOSED LOW IN THE UPPER GREAT LAKE REGION...SETTING UP A HIGHER AMPLITUDE TROUGH ACROSS THE WFO PAH FORECAST AREA BY 12Z THURSDAY. TIMING BETWEEN THESE MODELS VARIES...AS ECMWF DEVELOPS A NEGATIVE TILT WITH THE TROUGH...PLACING A GREATER EMPHASIS WITH THE SHORTWAVE MOVING THROUGH THE LOWER MS VALLEY. AT THIS TIME...WILL BLEND THE GFS/ECMWF SOLUTIONS FOR A MORE PROLONGED SHOWERY EVENT ON THURSDAY AND FRIDAY. THERE IS SOME DIVERGENCE IN SOLUTIONS ON THE IMPACT OF SHORTWAVES THAT DEVELOP ALONG A BUILDING RIDGE BEHIND THE THURSDAY/FRIDAY SYSTEM. FOR NOW...I HAVE INTRODUCED A SMALL CHANCE PRECIPITATION EVENT FOR SATURDAY. && .AVIATION... LINGERING MVFR CIGS SHOULD RAPIDLY DEPART KEVV AND KOWB AS 500MB UPPER LOW ACCELERATES NE AND SURFACE HIGH PRESSURE BUILDS IN BEHIND. LIKEWISE WITH RELAXING PRESSURE GRADIENT WINDS SHOULD GO BELOW 10 KNOTS AT ALL TAF SITES BY 22-00Z AND REMAIN THERE THRU LATE MORNING SUNDAY. COLD AIR STRATOCU...INCLUDING NEAR KCGI...SHOULD DISSIPATE TOWARD SUNSET AS WELL. TIME-HEIGHT PLOTS SHOW MEAN RH VALUES NEAR OR ABOVE 70% IN THE 1000-850 MB LAYER AT ALL SITES NEXT 24 HOURS OR SO...SO WILL KEEP AT LEAST SCATTERED MVFR LAYER IN TAFS. IN ADDITION...ANOTHER MOISTURE MAX MOVES IN FROM WEST TO EAST AT ABOUT THE 700-750MB LEVEL STARTING AT KCGI AT 06Z TO 10Z AT OWB. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...NONE. MO...NONE. IL...NONE. IN...NONE. && $$ SHORT/LONG TERM....SMITH AVIATION...SHANKLIN ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 1044 AM CST SAT MAR 8 2008 ZONE PACKAGE IS ON TARGET. && .PREV DISCUSSION... /ISSUED 336 AM CST SAT MAR 8 2008/ SHORT TERM... UPPER WAVE CURRENTLY MOVING ACROSS AREA PER WATER VAPOR IMAGERY IS GENERATING SOME VERY LIGHT RAIN AS SHOWN ON AREA RADARS AND SURFACE OBS. PER KLCH 00Z SOUNDING AND RUC FORECAST SOUNDINGS...PRECIP IS FALLING FROM AROUND 8-10K FEET THROUGH A FAIRLY DRY LAYER BENEATH...AND MUCH OF THIS ACTIVITY IS NOT REACHING THE GROUND. HOWEVER SOME POCKETS OF LIGHT RAIN WILL CONTINUE TO BE POSSIBLE THE NEXT FEW HOURS IN AREAS OF HIGHER REFLECTIVITIES...AND SOME VERY LIGHT SNOW COULD EVEN MIX IN AS PROFILE REMAINS SUPPORTIVE AND SURFACE TEMPERATURES ARE GENERALLY IN THE 30S. HOWEVER WITH ACTIVITY MOVING RAPIDLY EASTWARD AND ONLY TRACE AMOUNTS EXPECTED WILL NOT MENTION IN GRIDS OR ZONES FOR TODAY. OTHERWISE...HIGH PRESSURE WILL SETTLE OVER OUR REGION TODAY WITH CLEARING SKIES ALLOWING FOR TEMPERATURES TO WARM INTO THE 50S. THE HIGH WILL SHIFT EAST OF THE REGION TONIGHT INTO TOMORROW...WITH SOUTHERLY WINDS RETURNING LEADING TO MUCH WARMER TEMPERATURES FOR SUNDAY. MOISTURE LEVELS WILL BEGIN INCREASING SUNDAY NIGHT INTO MONDAY AS A POSITIVE-TILTED TROUGH DIGS SOUTHWARD INTO TEXAS. A WEAK SURFACE LOW IS EXPECTED TO DEVELOP NEAR BROWNSVILLE...WITH UPPER LIFT INCREASING ACROSS THE AREA AHEAD OF THE TROUGH ALONG WITH RISING PWATS. THIS WILL PROMPT THE DEVELOPMENT OF SHOWERS AND A FEW THUNDERSTORMS ACROSS SOUTHEAST TEXAS FROM MONDAY MORNING INTO THE AFTERNOON...WITH ACTIVITY SPREADING EASTWARD ACROSS THE FORECAST AREA MONDAY NIGHT INTO TUESDAY. HAVE LEANED TOWARDS GFS THIS PERIOD BUT NOT GONE AS HIGH ON POPS. FORECAST SOUNDINGS DEPICT A MOIST ADIABATIC PROFILE WITH LITTLE INSTABILITY...THUS NO STRONG THUNDERSTORMS ARE EXPECTED. MODEL QPF FIELDS AND HPC GUIDANCE INDICATE AFTER PRECIP TAPERS OFF LATE TUESDAY...FINAL RAINFALL TOTALS WITH THIS SYSTEM SHOULD RANGE BETWEEN ONE QUARTER INCH IN NORTHEAST ZONES TO AROUND ONE INCH IN SOUTHWEST ZONES. LONG TERM... AFOREMENTIONED SYSTEM WILL MOVE EAST OF THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY...WITH A BRIEF RESPITE IN THE RAIN CHANCES. MODELS THEN DIVERGE SIGNIFICANTLY WITH 00Z GFS INDICATING A DEEP UPPER TROF DIGGING SOUTHWARD INTO THE REGION AND ROBUST SURFACE LOW DEVELOPMENT TO OUR WEST ON THURSDAY...LEADING TO A SIGNIFICANT CHANCE OF SHOWERS AND STORMS. ON THE OTHER HAND...00Z ECMWF IS MUCH LESS AMPLIFIED AND FURTHER NORTH WITH THE TROF AND THUS GENERATES LITTLE TO NO PRECIP ACROSS THE CWA. WITH THE LARGE DISCREPANCIES WILL CONTINUE THE INHERITED LOW CHANCE POPS FOR THE WEDNESDAY NIGHT TO FRIDAY TIMEFRAME AND KEEP TEMPS NEAR AVERAGE. ACTIVE WEATHER PATTERN LOOKS TO CONTINUE WITH ANOTHER STORM SYSTEM POTENTIALLY AFFECTING OUR REGION LATE NEXT WEEKEND. AVIATION... OTHER THAN A FEW SPRINKLES POSSIBLE THROUGH 12Z AT AREA TERMINALS...VFR CONDITIONS ARE EXPECTED TODAY WITH LIGHT WINDS AND MOSTLY SUNNY SKIES. MARINE... MSAS ANALYSIS INDICATES WINDS HAVE FALLEN BELOW SCA CRITERIA ACROSS ALL WATERS AND WILL LOWER SCA FLAGS. GENERALLY LIGHT WINDS AND SEAS EXPECTED TODAY BEFORE SOUTHERLY FLOW RETURNS TONIGHT INTO TOMORROW. WINDS AND SEAS WILL INCREASE EARLY NEXT WEEK AS THE NEXT STORM SYSTEM IMPACTS THE AREA...WITH SURFACE LOW DEVELOPMENT IN THE GULF LEADING TO GUSTY EAST WINDS MONDAY AND TUESDAY ALONG WITH SCATTERED SHOWERS AND A FEW THUNDERSTORMS. ANOTHER STORM SYSTEM WILL POTENTIALLY AFFECT THE COASTAL WATERS LATE WEDNESDAY INTO FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... KLCH 58 37 69 51 / 0 0 0 0 KBPT 59 38 69 53 / 0 0 0 0 KAEX 53 32 68 46 / 0 0 0 0 KLFT 56 36 68 49 / 0 0 0 0 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 336 AM CST SAT MAR 8 2008 .SHORT TERM... UPPER WAVE CURRENTLY MOVING ACROSS AREA PER WATER VAPOR IMAGERY IS GENERATING SOME VERY LIGHT RAIN AS SHOWN ON AREA RADARS AND SURFACE OBS. PER KLCH 00Z SOUNDING AND RUC FORECAST SOUNDINGS...PRECIP IS FALLING FROM AROUND 8-10K FEET THROUGH A FAIRLY DRY LAYER BENEATH...AND MUCH OF THIS ACTIVITY IS NOT REACHING THE GROUND. HOWEVER SOME POCKETS OF LIGHT RAIN WILL CONTINUE TO BE POSSIBLE THE NEXT FEW HOURS IN AREAS OF HIGHER REFLECTIVITIES...AND SOME VERY LIGHT SNOW COULD EVEN MIX IN AS PROFILE REMAINS SUPPORTIVE AND SURFACE TEMPERATURES ARE GENERALLY IN THE 30S. HOWEVER WITH ACTIVITY MOVING RAPIDLY EASTWARD AND ONLY TRACE AMOUNTS EXPECTED WILL NOT MENTION IN GRIDS OR ZONES FOR TODAY. OTHERWISE...HIGH PRESSURE WILL SETTLE OVER OUR REGION TODAY WITH CLEARING SKIES ALLOWING FOR TEMPERATURES TO WARM INTO THE 50S. THE HIGH WILL SHIFT EAST OF THE REGION TONIGHT INTO TOMORROW...WITH SOUTHERLY WINDS RETURNING LEADING TO MUCH WARMER TEMPERATURES FOR SUNDAY. MOISTURE LEVELS WILL BEGIN INCREASING SUNDAY NIGHT INTO MONDAY AS A POSITIVE-TILTED TROUGH DIGS SOUTHWARD INTO TEXAS. A WEAK SURFACE LOW IS EXPECTED TO DEVELOP NEAR BROWNSVILLE...WITH UPPER LIFT INCREASING ACROSS THE AREA AHEAD OF THE TROUGH ALONG WITH RISING PWATS. THIS WILL PROMPT THE DEVELOPMENT OF SHOWERS AND A FEW THUNDERSTORMS ACROSS SOUTHEAST TEXAS FROM MONDAY MORNING INTO THE AFTERNOON...WITH ACTIVITY SPREADING EASTWARD ACROSS THE FORECAST AREA MONDAY NIGHT INTO TUESDAY. HAVE LEANED TOWARDS GFS THIS PERIOD BUT NOT GONE AS HIGH ON POPS. FORECAST SOUNDINGS DEPICT A MOIST ADIABATIC PROFILE WITH LITTLE INSTABILITY...THUS NO STRONG THUNDERSTORMS ARE EXPECTED. MODEL QPF FIELDS AND HPC GUIDANCE INDICATE AFTER PRECIP TAPERS OFF LATE TUESDAY...FINAL RAINFALL TOTALS WITH THIS SYSTEM SHOULD RANGE BETWEEN ONE QUARTER INCH IN NORTHEAST ZONES TO AROUND ONE INCH IN SOUTHWEST ZONES. .LONG TERM... AFOREMENTIONED SYSTEM WILL MOVE EAST OF THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY...WITH A BRIEF RESPITE IN THE RAIN CHANCES. MODELS THEN DIVERGE SIGNIFICANTLY WITH 00Z GFS INDICATING A DEEP UPPER TROF DIGGING SOUTHWARD INTO THE REGION AND ROBUST SURFACE LOW DEVELOPMENT TO OUR WEST ON THURSDAY...LEADING TO A SIGNIFICANT CHANCE OF SHOWERS AND STORMS. ON THE OTHER HAND...00Z ECMWF IS MUCH LESS AMPLIFIED AND FURTHER NORTH WITH THE TROF AND THUS GENERATES LITTLE TO NO PRECIP ACROSS THE CWA. WITH THE LARGE DISCREPANCIES WILL CONTINUE THE INHERITED LOW CHANCE POPS FOR THE WEDNESDAY NIGHT TO FRIDAY TIMEFRAME AND KEEP TEMPS NEAR AVERAGE. ACTIVE WEATHER PATTERN LOOKS TO CONTINUE WITH ANOTHER STORM SYSTEM POTENTIALLY AFFECTING OUR REGION LATE NEXT WEEKEND. && .AVIATION... OTHER THAN A FEW SPRINKLES POSSIBLE THROUGH 12Z AT AREA TERMINALS...VFR CONDITIONS ARE EXPECTED TODAY WITH LIGHT WINDS AND MOSTLY SUNNY SKIES. && .MARINE... MSAS ANALYSIS INDICATES WINDS HAVE FALLEN BELOW SCA CRITERIA ACROSS ALL WATERS AND WILL LOWER SCA FLAGS. GENERALLY LIGHT WINDS AND SEAS EXPECTED TODAY BEFORE SOUTHERLY FLOW RETURNS TONIGHT INTO TOMORROW. WINDS AND SEAS WILL INCREASE EARLY NEXT WEEK AS THE NEXT STORM SYSTEM IMPACTS THE AREA...WITH SURFACE LOW DEVELOPMENT IN THE GULF LEADING TO GUSTY EAST WINDS MONDAY AND TUESDAY ALONG WITH SCATTERED SHOWERS AND A FEW THUNDERSTORMS. ANOTHER STORM SYSTEM WILL POTENTIALLY AFFECT THE COASTAL WATERS LATE WEDNESDAY INTO FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... KLCH 58 37 69 51 / 0 0 0 0 KBPT 59 38 69 53 / 0 0 0 0 KAEX 53 32 68 46 / 0 0 0 0 KLFT 56 36 68 49 / 0 0 0 0 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ SHAMBURGER la AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 140 PM EDT SUN MAR 9 2008 UPDATED AVIATION SECTION FOR 18Z TAFS .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD TROUGH STRETCHING FROM NEW ENGLAND INTO THE GREAT LAKES REGION. WEAK ENE FLOW AHEAD OF SFC RIDGE OVER ONTARIO LOOKS LIKE IT MAY STILL BE PRODUCING FLURRIES IN DOWNTOWN MQT BUT OTHERWISE DRY CONDITIONS PREVAIL OVER THE REST OF THE CWA. && .DISCUSSION... TODAY...SOME LIGHT LES IS STILL POSSIBLE OVER NCNTRL AREAS FAVORED BY A ENE FLOW AS 850 MB TEMPS ARE AROUND -15C. SOME INCREASE IN LOW LEVEL MOISTURE COMBINED WITH DIURNAL HEATING AND FAIRLY STEEP SFC-850 MB LAPSE RATES OF 7C/KM OR GREATER COULD LEAD TO SOME ISOLATED DIURNAL SNOW SHOWERS OVER THE INTERIOR WEST HALF THIS AFTERNOON AS A WEAK SFC TROF MOVES ACROSS THE AREA. IF THE WRF-ARW QPF VERIFIES...A FEW LOCATIONS UNDER THE HEAVIER SNOW SHOWERS COULD SEE CLOSE TO AN INCH OF SNOW ACCUMULATION USING A 25/1 SNOW/WATER RATIO. TONIGHT...EXPECT CLEARING SKIES AS THE SFC RIDGE FROM ONTARIO DESCENDS OVER THE AREA. WITH LIGHT WINDS AND PCPN WATER AROUND .1 INCH...LOOK FOR IDEAL RADIATIONAL COOLING CONDITIONS. I FOLLOWED THE COLDER GFS BIAS-CORRECTED MOS GUIDANCE WHICH HIGHLIGHTED MIN TEMPS REACHING AROUND -15F IN SOME INTERIOR LOCATIONS OF THE EAST HALF. THESE FCST TEMPS SEEM TOTALLY REASONABLE GIVEN READINGS OBSERVED UPSTREAM THIS MORNING OVER ONTARIO IN PROXIMITY TO THE RIDGE. LOWS COULD EVEN DROP CLOSE TO -10F FOR FAVORED COLD SPOTS IN THE WESTERN INTERIOR BEFORE BOUNDARY LYR WINDS INCREASE OVERNIGHT ON BACK SIDE OF RIDGE AND AHEAD OF NEXT APPROACHING CLIPPER SYSTEM. AFTER A DRY MONDAY WITH TEMPERATURES WARMING BACK TOWARD THE FREEZING MARK IN WSW RETURN FLOW...CLOUDS WILL BE ON THE INCREASE MONDAY NIGHT. MODELS INDICATE TROUGH WILL NOT DIG ENOUGH TO THE SOUTHWEST TO BRING MUCH PCPN INTO UPR MI. BETTER CHANCES FOR PCPN WILL BE OVR LAKE SUPERIOR AND THE ERN FCST AREA CLOSER TO THE TRACK OF THE SHORTWAVE AND ASSOC SFC LOW. KEPT IN A SLIGHT CHC FOR NRN AND ERN TIER COUNTIES MON NIGHT WITH A SLIGHT CHC FOR ALL OF THE CWA ON TUE EXCEPT FOR LOW CHC POPS IN THE EAST. MODELS 1000-850MB THICKNESSES AND FCST SNDGS SUPPORT MORE SNOW AS PREDOMINANT PCPN TYPE MON NIGHT AND TUE. A VERY SHALLOW WARM LAYER NEAR SFC WITH DOWNSLOPING NW WINDS COULD SUPPORT A RAIN/SNOW MIX IN THE FAR SOUTH CENTRAL CWA. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... SCT-BKN LK SC/CU AT EACH SITE. NE-E WINDS KEEP A VERY SMALL CHANCE OF SOME LIGHT SNOW SHOWERS REDEVELOPING AT KSAW...BUT EXPECT MOST OF THE SNOW SHOWERS WILL OCCUR FARTHER INLAND. SKIES WILL CLEAR THIS EVENING AND SHOULD REMAIN CLEAR THROUGH TOMORROW AS HIGH PRESSURE RIDGE IS OVER THE AREA. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... 30.4 INCH HIGH PRESSURE WILL MOVE OVERHEAD LATE THIS AFTERNOON...BEFORE SLOWLY SHIFTING SOUTH TO WESTERN KENTUCKY BY LATE TUESDAY NIGHT. 29.8 INCH LOW PRESSURE FROM MANITOBA MONDAY AFTERNOON...WILL MOVE TO JUST NORTH OF LAKE SUPERIOR TUESDAY MORNING BEFORE SLIDING ACROSS UPPER MICHIGAN TUESDAY AFTERNOON. THIS LOW WILL BRING ABOUT THE NEXT CHANCE OF WINDS AT OR ABOVE 25 KTS. HIGH PRESSURE OF 30.0 INCHES WILL THEN BRIEFLY TAKE OVER TUESDAY NIGHT INTO EARLY WEDNESDAY. A 29.4 INCH LOW WILL MOVE INTO MANITOBA WEDNESDAY AND THROUGH CENTRAL LAKE SUPERIOR ON THURSDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/DISCUSSION...VOSS AVIATION...JLA MARINE...KF mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1241 PM EDT SUN MAR 9 2008 .AVIATION...SCT (VFR CIGS) LAKE CLOUDS WILL BE FOUND AT TVC EARLY IN THE AFTERNOON. OTHERWISE...DRY AIR ACROSS NRN MICHIGAN AND HIGH PRESSURE BUILDING SOUTH OUT OF ONTARIO...WILL LEAD TO VFR CONDITIONS AT TVC/PLN/APN THROUGH THE NEXT 24 HOURS (AND BEYOND)...WITH SOME SCT MID AND HIGH CLOUD MOVING THROUGH. ADAM && .UPDATE...ISSUED AT 1036 AM. VERY DRY BUT COLD AIRMASS REMAINS THE DOMINANT PLAYER ACROSS NORTHERN MICHIGAN THIS MORNING WITH SOLID BELOW ZERO LOW TEMPERATURES AT MANY INLAND AREAS. VERY WEAK SFC TROUGH BISECTING NRN LOWER MICHIGAN WHILE HIGH PRESSURE REBUILDING SOUTHWARD OUT OF ONTARIO. LIGHT NW FLOW OFF LAKE MICHIGAN HAS MANAGED TO GENERATE NARROW AREA OF LAKE SNOW SHOWERS OVERNIGHT AND THIS MORNING... IMPACTING THE SW COUNTIES WITH VSBYS STILL BRIEFLY DIPPING TO AROUND A MILE OR SO AT FKS/CAD. MINOR OVERNIGHT FLUFFY ACCUMULATIONS OF AN INCH OR LESS REPORTED BY SPOTTERS IN THOSE AREAS. FINALLY...MID LEVEL SHEAR AXIS STRETCHES FROM THE PLAINS INTO THE LOWER LAKES GENERATING SOME LIGHT SNOW NEAR CHICAGO AND THROWING HIGH CLOUD COVER INTO NRN MICHIGAN. REST OF TODAY...SIMILAR STORY TO THE LAST FEW DAYS WITH MINOR LAKE EFFECT CLOUDS/PRECIP STARTING OFF THE DAY. HOWEVER...WEAKENING MEAN LOW LEVEL FLOW/A DRY ANTECEDENT AIRMASS OVER THE REGION/DAYTIME MIXING AND MODERATING LOW LEVEL TEMPS SHOULD AGAIN DISSIPATE LAKE STCU AND SNOW SHOWER ACTIVITY BY EARLY AFTERNOON. MID LEVEL SHEAR AXIS TO THE SOUTH WILL CONTINUE TO TOSS THICKER MID-HIGH CLOUD COVER INTO NRN MICHIGAN...MAINLY THE SRN COUNTIES...BUT MAY HAVE ONLY MINIMAL IMPACT ON PERCEIVED SKY CONDITIONS. OVERALL...PLAN ON HAVING SUNNY/MOSTLY SUNNY SKIES FOR MOST AREAS THIS AFTERNOON...PARTLY SUNNY SKIES OVER THE FAR SRN COUNTIES EXCEPT FOR A FEW MORE HOURS OF CLOUDY SKIES/LIGHT SNOW SHOWERS IN THE SW AREAS. BELOW NORMAL AFTERNOON HIGH TEMPS ONCE AGAIN...ALTHOUGH WITH MODERATING LOW LEVEL TEMPS...READINGS EXPECTED TO BREAK INTO THE 20S JUST ABOUT EVERYWHERE. ADAM && .PREV DISCUSSION... /ISSUED 422 AM EDT SUN MAR 9 2008/ DISCUSSION...03Z SURFACE/RUC ANALYSIS AND IR/WV/RADAR IMAGERY SHOW A PERSISTENT AMPLIFIED PATTERN (POSITIVE PNA) ACROSS NORTH AMERICA...WITH THE EASTERN TROUGH CONSISTING OF DUAL 500MB CLOSED LOWS...ONE OVER MINNESOTA...AND THE OTHER OVER UPSTATE NEW YORK. WHILE THE LATTER IS EXITING TO THE NE...SMALLER SCALE SHORTWAVES ROTATING AROUND THE WESTERN UPPER LOW IS SUPPORTING LIGHT SNOW OVER MN AND IA IN A REGION OF MODEST 850-500MB -DIVQ. AIR ACROSS NORTHERN LOWER MICHIGAN IS MUCH DRIER JUDGING BY THE 00Z SOUNDINGS ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION THANKS TO LOW LEVEL RIDGING AND A POLAR CONTINENTAL AIRMASS. BECAUSE OF THIS DRY AIR...5-10KFT CLOUD DECK SPREADING EAST ACROSS WI/IL IS HAVING A DEVIL OF A TIME EXTENDING INTO NORTHERN MICHIGAN...RATHER PREFERRING TAKING A MORE SOUTHERN TRACK ACROSS SOUTHERN LOWER. ONLY A FEW LAKE EFFECT SNOW SHOWERS EXIST FROM MANISTEE TO THE LEELANAU PENINSULA AT THIS HOUR. FORECAST CONCERNS ARE MINIMAL FOR THIS TIME OF THE YEAR...AND CONSISTENT OF NUISANT LAKE EFFECT SNOW SHOWER POTENTIAL FIRST...THEN SKY AND TEMPS SECOND OVER THE NEXT 24 HOURS. TODAY...CLOSED LOW OVER MN WILL SHEAR OUT AS IT MIGRATES TOWARDS THE SOUTHERN GREAT LAKES. MID/UPPER LEVEL MOISTURE WILL ROTATE AROUND THE WEAK IOWA SHORTWAVE...PROGGED TO TRACK ACROSS NORTHERN IL/IN/OH...AND SPREAD MID/HIGH CLOUDS ACROSS NORTHERN MICHIGAN...THICKER AS YOU HEAD SOUTH. HOWEVER...VERY DRY AIR CENTERED AROUND 750MB WITH TRAJECTORIES ORIGINATING OUT OF NE ONTARIO AND QUEBEC WILL KEEP THE AREA PRECIP FREE. LAKE EFFECT WILL CONTINUE TO STRUGGLE TO REV UP ESPECIALLY WITH 850MB TEMPS MODERATING FROM -15C TO -13C AND LOW LEVEL WIND FLOW DIMINISHING TO LESS THAN 10KTS BY THIS AFTERNOON. THINK THAT ANY LIGHT SNOW SHOWER AND FLURRY ACTIVITY WILL BE CONFINED TO THE MORNING HOURS FROM THE MANISTEE TO GRAND TRAVERSE BAY CORRIDOR AND BE MOSTLY CONFINED TO THE LAKE SHORES. AS A RESULT...MOST LOCATIONS AWAY FROM THE AFOREMENTIONED AREA WILL SEE PARTLY IF NOT MOSTLY SUNNY SKIES FOR MUCH OF THE DAY. HIGHS IN THE LOW TO MID 20S LOOK FINE. TONIGHT...SHEARED TROUGH AXIS WILL PASS ACROSS THE STATE AND MID/UPPER LEVEL MOISTURE WILL THIN AS A RESULT. DO NOT BELIEVE THESE CLOUDS WILL HAVE MUCH OF AN IMPACT ON TEMPERATURES AND EXPECT ANOTHER EXCELLENT RADIATIONAL COOLING NIGHT IS IN STORE WITH SURFACE HIGH PRESSURE MAINTAINING ITS DOMINANCE ACROSS THE AREA. ONLY POSSIBLE PITFALL IS THAT LOW LEVEL WINDS INCREASE LATE AND SHALLOW INSTABILITY MAY BE ENOUGH FOR A COUPLE FLURRIES ALONG THE LAKE MICHIGAN SHORELINE. BUT THINK DRY AIR (850-700MB RH AROUND 10-20 PCT) AND LAND BREEZE INTERACTION WILL BE ENOUGH TO THWART ANY FLURRY ACTIVITY. LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. MONDAY AND MONDAY NIGHT...SHORTWAVE RIDGING MOVES IN ON MONDAY WHILE THE BROAD SURFACE HIGH PRESSURE SHIFTS SOUTH OF THE GREAT LAKES. WEAK WARM ADVECTION WILL ENSUE...ENOUGH TO BUMP UP TEMPS INTO THE LOW 30S. OUTSIDE OF SOME MORNING LAKE CLOUDS AND RESULTING DIURNAL CU (WHICH SHOULD MIX OUT BY EARLY AFTERNOON) AS WEST FLOW STRENGTHENS...MOST AREAS WILL SEE MOSTLY SUNNY SKIES BY MID TO LATE AFTERNOON. MID/UPPER LEVEL CLOUDS WILL BE ON THE INCREASE TOWARDS EVENING AS MOISTURE SPREADS IN AHEAD OF THE NEXT CLIPPER SHORTWAVE. ISENTROPIC ASCENT INCREASES AS WELL...BUT LIMITED MOISTURE BELOW 700MB WILL PREVENT ANY PRECIP FROM REACHING THE GROUND. WITH STRENGTHENING SW FLOW AND INVASION OF WARMER AIR...LOWS WILL BE 15 TO 20 DEGREES WARMER THAN SUNDAY NIGHT. TUESDAY THROUGH THURSDAY...APPROACHING CLIPPER SHORTWAVE PASSES ACROSS LAKE SUPERIOR AND NORTHERN LAKE HURON ON TUESDAY. BEST QG FORCING WILL LIE AHEAD AND TO THE NORTH OF THE SHORTWAVE. GFS IS AN OUTLIER IN THIS REGARD...AND BRINGS A WEAK ASSOCIATED SURFACE LOW AND WIDE SWATH OF PRECIP ACROSS NORTHERN LOWER...WHILE OTHER LEADING MODELS KEEP PRECIP CHANCES NORTH OF THE STRAITS. REGARDLESS...THERMAL PROFILES SUGGEST PRECIP WILL FALL AS ALL SNOW...EVEN IN THE SOUTHERN GFS SOLUTION AND HAVE REMOVED RAIN MENTION. WILL KEEP LOW CHANCE POP ALL THE WAY TO M-55 HOWEVER...BUT WOULDN/T BE SURPRISED IF PRECIP CHANCES ARE REMOVED ACROSS THE SOUTHERN CWA. SHORTWAVE RIDGING AND SURFACE HIGH PRESSURE RETURN TUESDAY NIGHT INTO WEDNESDAY. A CHANCE OF PRECIP THEN ARRIVES WEDNESDAY NIGHT INTO THURSDAY. HIGH TEMPERATURES IN THE UPPER 30S TO LOW 40S OVER THIS PERIOD. MPC && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. LH...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1036 AM EDT SUN MAR 9 2008 .UPDATE...VERY DRY BUT COLD AIRMASS REMAINS THE DOMINANT PLAYER ACROSS NORTHERN MICHIGAN THIS MORNING WITH SOLID BELOW ZERO LOW TEMPERATURES AT MANY INLAND AREAS. VERY WEAK SFC TROUGH BISECTING NRN LOWER MICHIGAN WHILE HIGH PRESSURE REBUILDING SOUTHWARD OUT OF ONTARIO. LIGHT NW FLOW OFF LAKE MICHIGAN HAS MANAGED TO GENERATE NARROW AREA OF LAKE SNOW SHOWERS OVERNIGHT AND THIS MORNING... IMPACTING THE SW COUNTIES WITH VSBYS STILL BRIEFLY DIPPING TO AROUND A MILE OR SO AT FKS/CAD. MINOR OVERNIGHT FLUFFY ACCUMULATIONS OF AN INCH OR LESS REPORTED BY SPOTTERS IN THOSE AREAS. FINALLY...MID LEVEL SHEAR AXIS STRETCHES FROM THE PLAINS INTO THE LOWER LAKES GENERATING SOME LIGHT SNOW NEAR CHICAGO AND THROWING HIGH CLOUD COVER INTO NRN MICHIGAN. REST OF TODAY...SIMILAR STORY TO THE LAST FEW DAYS WITH MINOR LAKE EFFECT CLOUDS/PRECIP STARTING OFF THE DAY. HOWEVER...WEAKENING MEAN LOW LEVEL FLOW/A DRY ANTECEDENT AIRMASS OVER THE REGION/DAYTIME MIXING AND MODERATING LOW LEVEL TEMPS SHOULD AGAIN DISSIPATE LAKE STCU AND SNOW SHOWER ACTIVITY BY EARLY AFTERNOON. MID LEVEL SHEAR AXIS TO THE SOUTH WILL CONTINUE TO TOSS THICKER MID-HIGH CLOUD COVER INTO NRN MICHIGAN...MAINLY THE SRN COUNTIES...BUT MAY HAVE ONLY MINIMAL IMPACT ON PERCEIVED SKY CONDITIONS. OVERALL...PLAN ON HAVING SUNNY/MOSTLY SUNNY SKIES FOR MOST AREAS THIS AFTERNOON...PARTLY SUNNY SKIES OVER THE FAR SRN COUNTIES EXCEPT FOR A FEW MORE HOURS OF CLOUDY SKIES/LIGHT SNOW SHOWERS IN THE SW AREAS. BELOW NORMAL AFTERNOON HIGH TEMPS ONCE AGAIN...ALTHOUGH WITH MODERATING LOW LEVEL TEMPS...READINGS EXPECTED TO BREAK INTO THE 20S JUST ABOUT EVERYWHERE. ADAM && .AVIATION...ISSUED AT 705 AM. VERY FEW CONCERNS OVER THE NEXT 24 HOURS. LAKE CLOUDS WILL PRODUCE MVFR CIGS AND FLURRIES AT TVC THIS MORNING. WEAKENING WIND FIELDS COMBINED WITH MIXING SHOULD HELP CIGS RISE AND SCATTER BY MIDDAY OR NOT TOO LONG THEREAFTER. OUTSIDE OF POSSIBLE DIURNAL CU AROUND MIDDAY AT APN...ALL TAF SITES SHOULD SEE VFR CONDITIONS PREVAIL. MPC && .PREV DISCUSSION... /ISSUED 422 AM EDT SUN MAR 9 2008/ DISCUSSION...03Z SURFACE/RUC ANALYSIS AND IR/WV/RADAR IMAGERY SHOW A PERSISTENT AMPLIFIED PATTERN (POSITIVE PNA) ACROSS NORTH AMERICA...WITH THE EASTERN TROUGH CONSISTING OF DUAL 500MB CLOSED LOWS...ONE OVER MINNESOTA...AND THE OTHER OVER UPSTATE NEW YORK. WHILE THE LATTER IS EXITING TO THE NE...SMALLER SCALE SHORTWAVES ROTATING AROUND THE WESTERN UPPER LOW IS SUPPORTING LIGHT SNOW OVER MN AND IA IN A REGION OF MODEST 850-500MB -DIVQ. AIR ACROSS NORTHERN LOWER MICHIGAN IS MUCH DRIER JUDGING BY THE 00Z SOUNDINGS ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION THANKS TO LOW LEVEL RIDGING AND A POLAR CONTINENTAL AIRMASS. BECAUSE OF THIS DRY AIR...5-10KFT CLOUD DECK SPREADING EAST ACROSS WI/IL IS HAVING A DEVIL OF A TIME EXTENDING INTO NORTHERN MICHIGAN...RATHER PREFERRING TAKING A MORE SOUTHERN TRACK ACROSS SOUTHERN LOWER. ONLY A FEW LAKE EFFECT SNOW SHOWERS EXIST FROM MANISTEE TO THE LEELANAU PENINSULA AT THIS HOUR. FORECAST CONCERNS ARE MINIMAL FOR THIS TIME OF THE YEAR...AND CONSISTENT OF NUISANT LAKE EFFECT SNOW SHOWER POTENTIAL FIRST...THEN SKY AND TEMPS SECOND OVER THE NEXT 24 HOURS. TODAY...CLOSED LOW OVER MN WILL SHEAR OUT AS IT MIGRATES TOWARDS THE SOUTHERN GREAT LAKES. MID/UPPER LEVEL MOISTURE WILL ROTATE AROUND THE WEAK IOWA SHORTWAVE...PROGGED TO TRACK ACROSS NORTHERN IL/IN/OH...AND SPREAD MID/HIGH CLOUDS ACROSS NORTHERN MICHIGAN...THICKER AS YOU HEAD SOUTH. HOWEVER...VERY DRY AIR CENTERED AROUND 750MB WITH TRAJECTORIES ORIGINATING OUT OF NE ONTARIO AND QUEBEC WILL KEEP THE AREA PRECIP FREE. LAKE EFFECT WILL CONTINUE TO STRUGGLE TO REV UP ESPECIALLY WITH 850MB TEMPS MODERATING FROM -15C TO -13C AND LOW LEVEL WIND FLOW DIMINISHING TO LESS THAN 10KTS BY THIS AFTERNOON. THINK THAT ANY LIGHT SNOW SHOWER AND FLURRY ACTIVITY WILL BE CONFINED TO THE MORNING HOURS FROM THE MANISTEE TO GRAND TRAVERSE BAY CORRIDOR AND BE MOSTLY CONFINED TO THE LAKE SHORES. AS A RESULT...MOST LOCATIONS AWAY FROM THE AFOREMENTIONED AREA WILL SEE PARTLY IF NOT MOSTLY SUNNY SKIES FOR MUCH OF THE DAY. HIGHS IN THE LOW TO MID 20S LOOK FINE. TONIGHT...SHEARED TROUGH AXIS WILL PASS ACROSS THE STATE AND MID/UPPER LEVEL MOISTURE WILL THIN AS A RESULT. DO NOT BELIEVE THESE CLOUDS WILL HAVE MUCH OF AN IMPACT ON TEMPERATURES AND EXPECT ANOTHER EXCELLENT RADIATIONAL COOLING NIGHT IS IN STORE WITH SURFACE HIGH PRESSURE MAINTAINING ITS DOMINANCE ACROSS THE AREA. ONLY POSSIBLE PITFALL IS THAT LOW LEVEL WINDS INCREASE LATE AND SHALLOW INSTABILITY MAY BE ENOUGH FOR A COUPLE FLURRIES ALONG THE LAKE MICHIGAN SHORELINE. BUT THINK DRY AIR (850-700MB RH AROUND 10-20 PCT) AND LAND BREEZE INTERACTION WILL BE ENOUGH TO THWART ANY FLURRY ACTIVITY. LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. MONDAY AND MONDAY NIGHT...SHORTWAVE RIDGING MOVES IN ON MONDAY WHILE THE BROAD SURFACE HIGH PRESSURE SHIFTS SOUTH OF THE GREAT LAKES. WEAK WARM ADVECTION WILL ENSUE...ENOUGH TO BUMP UP TEMPS INTO THE LOW 30S. OUTSIDE OF SOME MORNING LAKE CLOUDS AND RESULTING DIURNAL CU (WHICH SHOULD MIX OUT BY EARLY AFTERNOON) AS WEST FLOW STRENGTHENS...MOST AREAS WILL SEE MOSTLY SUNNY SKIES BY MID TO LATE AFTERNOON. MID/UPPER LEVEL CLOUDS WILL BE ON THE INCREASE TOWARDS EVENING AS MOISTURE SPREADS IN AHEAD OF THE NEXT CLIPPER SHORTWAVE. ISENTROPIC ASCENT INCREASES AS WELL...BUT LIMITED MOISTURE BELOW 700MB WILL PREVENT ANY PRECIP FROM REACHING THE GROUND. WITH STRENGTHENING SW FLOW AND INVASION OF WARMER AIR...LOWS WILL BE 15 TO 20 DEGREES WARMER THAN SUNDAY NIGHT. TUESDAY THROUGH THURSDAY...APPROACHING CLIPPER SHORTWAVE PASSES ACROSS LAKE SUPERIOR AND NORTHERN LAKE HURON ON TUESDAY. BEST QG FORCING WILL LIE AHEAD AND TO THE NORTH OF THE SHORTWAVE. GFS IS AN OUTLIER IN THIS REGARD...AND BRINGS A WEAK ASSOCIATED SURFACE LOW AND WIDE SWATH OF PRECIP ACROSS NORTHERN LOWER...WHILE OTHER LEADING MODELS KEEP PRECIP CHANCES NORTH OF THE STRAITS. REGARDLESS...THERMAL PROFILES SUGGEST PRECIP WILL FALL AS ALL SNOW...EVEN IN THE SOUTHERN GFS SOLUTION AND HAVE REMOVED RAIN MENTION. WILL KEEP LOW CHANCE POP ALL THE WAY TO M-55 HOWEVER...BUT WOULDN/T BE SURPRISED IF PRECIP CHANCES ARE REMOVED ACROSS THE SOUTHERN CWA. SHORTWAVE RIDGING AND SURFACE HIGH PRESSURE RETURN TUESDAY NIGHT INTO WEDNESDAY. A CHANCE OF PRECIP THEN ARRIVES WEDNESDAY NIGHT INTO THURSDAY. HIGH TEMPERATURES IN THE UPPER 30S TO LOW 40S OVER THIS PERIOD. MPC && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. LH...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 741 AM EDT SUN MAR 9 2008 .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD TROUGH STRETCHING FROM NEW ENGLAND INTO THE GREAT LAKES REGION. WEAK ENE FLOW AHEAD OF SFC RIDGE OVER ONTARIO LOOKS LIKE IT MAY STILL BE PRODUCING FLURRIES IN DOWNTOWN MQT BUT OTHERWISE DRY CONDITIONS PREVAIL OVER THE REST OF THE CWA. && .DISCUSSION... TODAY...SOME LIGHT LES IS STILL POSSIBLE OVER NCNTRL AREAS FAVORED BY A ENE FLOW AS 850 MB TEMPS ARE AROUND -15C. SOME INCREASE IN LOW LEVEL MOISTURE COMBINED WITH DIURNAL HEATING AND FAIRLY STEEP SFC-850 MB LAPSE RATES OF 7C/KM OR GREATER COULD LEAD TO SOME ISOLATED DIURNAL SNOW SHOWERS OVER THE INTERIOR WEST HALF THIS AFTERNOON AS A WEAK SFC TROF MOVES ACROSS THE AREA. IF THE WRF-ARW QPF VERIFIES...A FEW LOCATIONS UNDER THE HEAVIER SNOW SHOWERS COULD SEE CLOSE TO AN INCH OF SNOW ACCUMULATION USING A 25/1 SNOW/WATER RATIO. TONIGHT...EXPECT CLEARING SKIES AS THE SFC RIDGE FROM ONTARIO DESCENDS OVER THE AREA. WITH LIGHT WINDS AND PCPN WATER AROUND .1 INCH...LOOK FOR IDEAL RADIATIONAL COOLING CONDITIONS. I FOLLOWED THE COLDER GFS BIAS-CORRECTED MOS GUIDANCE WHICH HIGHLIGHTED MIN TEMPS REACHING AROUND -15F IN SOME INTERIOR LOCATIONS OF THE EAST HALF. THESE FCST TEMPS SEEM TOTALLY REASONABLE GIVEN READINGS OBSERVED UPSTREAM THIS MORNING OVER ONTARIO IN PROXIMITY TO THE RIDGE. LOWS COULD EVEN DROP CLOSE TO -10F FOR FAVORED COLD SPOTS IN THE WESTERN INTERIOR BEFORE BOUNDARY LYR WINDS INCREASE OVERNIGHT ON BACK SIDE OF RIDGE AND AHEAD OF NEXT APPROACHING CLIPPER SYSTEM. AFTER A DRY MONDAY WITH TEMPERATURES WARMING BACK TOWARD THE FREEZING MARK IN WSW RETURN FLOW...CLOUDS WILL BE ON THE INCREASE MONDAY NIGHT. MODELS INDICATE TROUGH WILL NOT DIG ENOUGH TO THE SOUTHWEST TO BRING MUCH PCPN INTO UPR MI. BETTER CHANCES FOR PCPN WILL BE OVR LAKE SUPERIOR AND THE ERN FCST AREA CLOSER TO THE TRACK OF THE SHORTWAVE AND ASSOC SFC LOW. KEPT IN A SLIGHT CHC FOR NRN AND ERN TIER COUNTIES MON NIGHT WITH A SLIGHT CHC FOR ALL OF THE CWA ON TUE EXCEPT FOR LOW CHC POPS IN THE EAST. MODELS 1000-850MB THICKNESSES AND FCST SNDGS SUPPORT MORE SNOW AS PREDOMINANT PCPN TYPE MON NIGHT AND TUE. A VERY SHALLOW WARM LAYER NEAR SFC WITH DOWNSLOPING NW WINDS COULD SUPPORT A RAIN/SNOW MIX IN THE FAR SOUTH CENTRAL CWA. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... A STREAM OF MVFR CEIGS THE DEVELOPED OVER UPPER MICHIGAN PRIOR TO 09Z...BUT HAS SIGNIFICANTLY WEAKENED SINCE THEN. SO MOSTLY VFR CONDITIONS WILL CONTINUE...BUT HAVE TO WORRY ABOUT MVFR CIGS POSSIBLY COMING IN FROM THE LAKE WITH NE FLOW AND POSSIBLE UPSLOPE THROUGH THIS AFTERNOON. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... 30.4 INCH HIGH PRESSURE WILL MOVE OVERHEAD LATE THIS AFTERNOON...BEFORE SLOWLY SHIFTING SOUTH TO WESTERN KENTUCKY BY LATE TUESDAY NIGHT. 29.8 INCH LOW PRESSURE FROM MANITOBA MONDAY AFTERNOON...WILL MOVE TO JUST NORTH OF LAKE SUPERIOR TUESDAY MORNING BEFORE SLIDING ACROSS UPPER MICHIGAN TUESDAY AFTERNOON. THIS LOW WILL BRING ABOUT THE NEXT CHANCE OF WINDS AT OR ABOVE 25 KTS. HIGH PRESSURE OF 30.0 INCHES WILL THEN BRIEFLY TAKE OVER TUESDAY NIGHT INTO EARLY WEDNESDAY. A 29.4 INCH LOW WILL MOVE INTO MANITOBA WEDNESDAY AND THROUGH CENTRAL LAKE SUPERIOR ON THURSDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...HEAVY FREEZING SPRAY WARNING THROUGH 8 AM EDT SUNDAY FOR LSZ267. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/DISCUSSION...VOSS AVIATION...KF MARINE...KF mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 705 AM EDT SUN MAR 9 2008 .AVIATION...VERY FEW CONCERNS OVER THE NEXT 24 HOURS. LAKE CLOUDS WILL PRODUCE MVFR CIGS AND FLURRIES AT TVC THIS MORNING. WEAKENING WIND FIELDS COMBINED WITH MIXING SHOULD HELP CIGS RISE AND SCATTER BY MIDDAY OR NOT TOO LONG THEREAFTER. OUTSIDE OF POSSIBLE DIURNAL CU AROUND MIDDAY AT APN...ALL TAF SITES SHOULD SEE VFR CONDITIONS PREVAIL. MPC && .PREV DISCUSSION... /ISSUED 422 AM EDT SUN MAR 9 2008/ DISCUSSION...03Z SURFACE/RUC ANALYSIS AND IR/WV/RADAR IMAGERY SHOW A PERSISTENT AMPLIFIED PATTERN (POSITIVE PNA) ACROSS NORTH AMERICA...WITH THE EASTERN TROUGH CONSISTING OF DUAL 500MB CLOSED LOWS...ONE OVER MINNESOTA...AND THE OTHER OVER UPSTATE NEW YORK. WHILE THE LATTER IS EXITING TO THE NE...SMALLER SCALE SHORTWAVES ROTATING AROUND THE WESTERN UPPER LOW IS SUPPORTING LIGHT SNOW OVER MN AND IA IN A REGION OF MODEST 850-500MB -DIVQ. AIR ACROSS NORTHERN LOWER MICHIGAN IS MUCH DRIER JUDGING BY THE 00Z SOUNDINGS ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION THANKS TO LOW LEVEL RIDGING AND A POLAR CONTINENTAL AIRMASS. BECAUSE OF THIS DRY AIR...5-10KFT CLOUD DECK SPREADING EAST ACROSS WI/IL IS HAVING A DEVIL OF A TIME EXTENDING INTO NORTHERN MICHIGAN...RATHER PREFERRING TAKING A MORE SOUTHERN TRACK ACROSS SOUTHERN LOWER. ONLY A FEW LAKE EFFECT SNOW SHOWERS EXIST FROM MANISTEE TO THE LEELANAU PENINSULA AT THIS HOUR. FORECAST CONCERNS ARE MINIMAL FOR THIS TIME OF THE YEAR...AND CONSISTENT OF NUISANT LAKE EFFECT SNOW SHOWER POTENTIAL FIRST...THEN SKY AND TEMPS SECOND OVER THE NEXT 24 HOURS. TODAY...CLOSED LOW OVER MN WILL SHEAR OUT AS IT MIGRATES TOWARDS THE SOUTHERN GREAT LAKES. MID/UPPER LEVEL MOISTURE WILL ROTATE AROUND THE WEAK IOWA SHORTWAVE...PROGGED TO TRACK ACROSS NORTHERN IL/IN/OH...AND SPREAD MID/HIGH CLOUDS ACROSS NORTHERN MICHIGAN...THICKER AS YOU HEAD SOUTH. HOWEVER...VERY DRY AIR CENTERED AROUND 750MB WITH TRAJECTORIES ORIGINATING OUT OF NE ONTARIO AND QUEBEC WILL KEEP THE AREA PRECIP FREE. LAKE EFFECT WILL CONTINUE TO STRUGGLE TO REV UP ESPECIALLY WITH 850MB TEMPS MODERATING FROM -15C TO -13C AND LOW LEVEL WIND FLOW DIMINISHING TO LESS THAN 10KTS BY THIS AFTERNOON. THINK THAT ANY LIGHT SNOW SHOWER AND FLURRY ACTIVITY WILL BE CONFINED TO THE MORNING HOURS FROM THE MANISTEE TO GRAND TRAVERSE BAY CORRIDOR AND BE MOSTLY CONFINED TO THE LAKE SHORES. AS A RESULT...MOST LOCATIONS AWAY FROM THE AFOREMENTIONED AREA WILL SEE PARTLY IF NOT MOSTLY SUNNY SKIES FOR MUCH OF THE DAY. HIGHS IN THE LOW TO MID 20S LOOK FINE. TONIGHT...SHEARED TROUGH AXIS WILL PASS ACROSS THE STATE AND MID/UPPER LEVEL MOISTURE WILL THIN AS A RESULT. DO NOT BELIEVE THESE CLOUDS WILL HAVE MUCH OF AN IMPACT ON TEMPERATURES AND EXPECT ANOTHER EXCELLENT RADIATIONAL COOLING NIGHT IS IN STORE WITH SURFACE HIGH PRESSURE MAINTAINING ITS DOMINANCE ACROSS THE AREA. ONLY POSSIBLE PITFALL IS THAT LOW LEVEL WINDS INCREASE LATE AND SHALLOW INSTABILITY MAY BE ENOUGH FOR A COUPLE FLURRIES ALONG THE LAKE MICHIGAN SHORELINE. BUT THINK DRY AIR (850-700MB RH AROUND 10-20 PCT) AND LAND BREEZE INTERACTION WILL BE ENOUGH TO THWART ANY FLURRY ACTIVITY. LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. MONDAY AND MONDAY NIGHT...SHORTWAVE RIDGING MOVES IN ON MONDAY WHILE THE BROAD SURFACE HIGH PRESSURE SHIFTS SOUTH OF THE GREAT LAKES. WEAK WARM ADVECTION WILL ENSUE...ENOUGH TO BUMP UP TEMPS INTO THE LOW 30S. OUTSIDE OF SOME MORNING LAKE CLOUDS AND RESULTING DIURNAL CU (WHICH SHOULD MIX OUT BY EARLY AFTERNOON) AS WEST FLOW STRENGTHENS...MOST AREAS WILL SEE MOSTLY SUNNY SKIES BY MID TO LATE AFTERNOON. MID/UPPER LEVEL CLOUDS WILL BE ON THE INCREASE TOWARDS EVENING AS MOISTURE SPREADS IN AHEAD OF THE NEXT CLIPPER SHORTWAVE. ISENTROPIC ASCENT INCREASES AS WELL...BUT LIMITED MOISTURE BELOW 700MB WILL PREVENT ANY PRECIP FROM REACHING THE GROUND. WITH STRENGTHENING SW FLOW AND INVASION OF WARMER AIR...LOWS WILL BE 15 TO 20 DEGREES WARMER THAN SUNDAY NIGHT. TUESDAY THROUGH THURSDAY...APPROACHING CLIPPER SHORTWAVE PASSES ACROSS LAKE SUPERIOR AND NORTHERN LAKE HURON ON TUESDAY. BEST QG FORCING WILL LIE AHEAD AND TO THE NORTH OF THE SHORTWAVE. GFS IS AN OUTLIER IN THIS REGARD...AND BRINGS A WEAK ASSOCIATED SURFACE LOW AND WIDE SWATH OF PRECIP ACROSS NORTHERN LOWER...WHILE OTHER LEADING MODELS KEEP PRECIP CHANCES NORTH OF THE STRAITS. REGARDLESS...THERMAL PROFILES SUGGEST PRECIP WILL FALL AS ALL SNOW...EVEN IN THE SOUTHERN GFS SOLUTION AND HAVE REMOVED RAIN MENTION. WILL KEEP LOW CHANCE POP ALL THE WAY TO M-55 HOWEVER...BUT WOULDNT BE SURPRISED IF PRECIP CHANCES ARE REMOVED ACROSS THE SOUTHERN CWA. SHORTWAVE RIDGING AND SURFACE HIGH PRESSURE RETURN TUESDAY NIGHT INTO WEDNESDAY. A CHANCE OF PRECIP THEN ARRIVES WEDNESDAY NIGHT INTO THURSDAY. HIGH TEMPERATURES IN THE UPPER 30S TO LOW 40S OVER THIS PERIOD. MPC AVIATION.../ISSUED 1112 PM EST SAT MAR 8 2008/ A QUIET 24 HOURS COMING UP WITH LIGHT WINDS AND CLEAR SKIES. THE ONLY CLOUDS THAT WILL BE AROUND WILL BE SCT HIGH CLOUDS ABOVE 20000 FT OR SOME SCT LAKE CLOUDS AROUND 3500 FT. NO PRECIPITATION IS EXPECTED AT ANY OF THE TAF SITES DURING THE NEXT 24 HOURS. LUTZ && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. LH...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 422 AM EDT SUN MAR 9 2008 .DISCUSSION...03Z SURFACE/RUC ANALYSIS AND IR/WV/RADAR IMAGERY SHOW A PERSISTENT AMPLIFIED PATTERN (POSITIVE PNA) ACROSS NORTH AMERICA...WITH THE EASTERN TROUGH CONSISTING OF DUAL 500MB CLOSED LOWS...ONE OVER MINNESOTA...AND THE OTHER OVER UPSTATE NEW YORK. WHILE THE LATTER IS EXITING TO THE NE...SMALLER SCALE SHORTWAVES ROTATING AROUND THE WESTERN UPPER LOW IS SUPPORTING LIGHT SNOW OVER MN AND IA IN A REGION OF MODEST 850-500MB -DIVQ. AIR ACROSS NORTHERN LOWER MICHIGAN IS MUCH DRIER JUDGING BY THE 00Z SOUNDINGS ACROSS THE UPPER MIDWEST AND GREAT LAKES REGION THANKS TO LOW LEVEL RIDGING AND A POLAR CONTINENTAL AIRMASS. BECAUSE OF THIS DRY AIR...5-10KFT CLOUD DECK SPREADING EAST ACROSS WI/IL IS HAVING A DEVIL OF A TIME EXTENDING INTO NORTHERN MICHIGAN...RATHER PREFERRING TAKING A MORE SOUTHERN TRACK ACROSS SOUTHERN LOWER. ONLY A FEW LAKE EFFECT SNOW SHOWERS EXIST FROM MANISTEE TO THE LEELANAU PENINSULA AT THIS HOUR. FORECAST CONCERNS ARE MINIMAL FOR THIS TIME OF THE YEAR...AND CONSISTENT OF NUISANT LAKE EFFECT SNOW SHOWER POTENTIAL FIRST...THEN SKY AND TEMPS SECOND OVER THE NEXT 24 HOURS. TODAY...CLOSED LOW OVER MN WILL SHEAR OUT AS IT MIGRATES TOWARDS THE SOUTHERN GREAT LAKES. MID/UPPER LEVEL MOISTURE WILL ROTATE AROUND THE WEAK IOWA SHORTWAVE...PROGGED TO TRACK ACROSS NORTHERN IL/IN/OH...AND SPREAD MID/HIGH CLOUDS ACROSS NORTHERN MICHIGAN...THICKER AS YOU HEAD SOUTH. HOWEVER...VERY DRY AIR CENTERED AROUND 750MB WITH TRAJECTORIES ORIGINATING OUT OF NE ONTARIO AND QUEBEC WILL KEEP THE AREA PRECIP FREE. LAKE EFFECT WILL CONTINUE TO STRUGGLE TO REV UP ESPECIALLY WITH 850MB TEMPS MODERATING FROM -15C TO -13C AND LOW LEVEL WIND FLOW DIMINISHING TO LESS THAN 10KTS BY THIS AFTERNOON. THINK THAT ANY LIGHT SNOW SHOWER AND FLURRY ACTIVITY WILL BE CONFINED TO THE MORNING HOURS FROM THE MANISTEE TO GRAND TRAVERSE BAY CORRIDOR AND BE MOSTLY CONFINED TO THE LAKE SHORES. AS A RESULT...MOST LOCATIONS AWAY FROM THE AFOREMENTIONED AREA WILL SEE PARTLY IF NOT MOSTLY SUNNY SKIES FOR MUCH OF THE DAY. HIGHS IN THE LOW TO MID 20S LOOK FINE. TONIGHT...SHEARED TROUGH AXIS WILL PASS ACROSS THE STATE AND MID/UPPER LEVEL MOISTURE WILL THIN AS A RESULT. DO NOT BELIEVE THESE CLOUDS WILL HAVE MUCH OF AN IMPACT ON TEMPERATURES AND EXPECT ANOTHER EXCELLENT RADIATIONAL COOLING NIGHT IS IN STORE WITH SURFACE HIGH PRESSURE MAINTAINING ITS DOMINANCE ACROSS THE AREA. ONLY POSSIBLE PITFALL IS THAT LOW LEVEL WINDS INCREASE LATE AND SHALLOW INSTABILITY MAY BE ENOUGH FOR A COUPLE FLURRIES ALONG THE LAKE MICHIGAN SHORELINE. BUT THINK DRY AIR (850-700MB RH AROUND 10-20 PCT) AND LAND BREEZE INTERACTION WILL BE ENOUGH TO THWART ANY FLURRY ACTIVITY. LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. MONDAY AND MONDAY NIGHT...SHORTWAVE RIDGING MOVES IN ON MONDAY WHILE THE BROAD SURFACE HIGH PRESSURE SHIFTS SOUTH OF THE GREAT LAKES. WEAK WARM ADVECTION WILL ENSUE...ENOUGH TO BUMP UP TEMPS INTO THE LOW 30S. OUTSIDE OF SOME MORNING LAKE CLOUDS AND RESULTING DIURNAL CU (WHICH SHOULD MIX OUT BY EARLY AFTERNOON) AS WEST FLOW STRENGTHENS...MOST AREAS WILL SEE MOSTLY SUNNY SKIES BY MID TO LATE AFTERNOON. MID/UPPER LEVEL CLOUDS WILL BE ON THE INCREASE TOWARDS EVENING AS MOISTURE SPREADS IN AHEAD OF THE NEXT CLIPPER SHORTWAVE. ISENTROPIC ASCENT INCREASES AS WELL...BUT LIMITED MOISTURE BELOW 700MB WILL PREVENT ANY PRECIP FROM REACHING THE GROUND. WITH STRENGTHENING SW FLOW AND INVASION OF WARMER AIR...LOWS WILL BE 15 TO 20 DEGREES WARMER THAN SUNDAY NIGHT. TUESDAY THROUGH THURSDAY...APPROACHING CLIPPER SHORTWAVE PASSES ACROSS LAKE SUPERIOR AND NORTHERN LAKE HURON ON TUESDAY. BEST QG FORCING WILL LIE AHEAD AND TO THE NORTH OF THE SHORTWAVE. GFS IS AN OUTLIER IN THIS REGARD...AND BRINGS A WEAK ASSOCIATED SURFACE LOW AND WIDE SWATH OF PRECIP ACROSS NORTHERN LOWER...WHILE OTHER LEADING MODELS KEEP PRECIP CHANCES NORTH OF THE STRAITS. REGARDLESS...THERMAL PROFILES SUGGEST PRECIP WILL FALL AS ALL SNOW...EVEN IN THE SOUTHERN GFS SOLUTION AND HAVE REMOVED RAIN MENTION. WILL KEEP LOW CHANCE POP ALL THE WAY TO M-55 HOWEVER...BUT WOULDNT BE SURPRISED IF PRECIP CHANCES ARE REMOVED ACROSS THE SOUTHERN CWA. SHORTWAVE RIDGING AND SURFACE HIGH PRESSURE RETURN TUESDAY NIGHT INTO WEDNESDAY. A CHANCE OF PRECIP THEN ARRIVES WEDNESDAY NIGHT INTO THURSDAY. HIGH TEMPERATURES IN THE UPPER 30S TO LOW 40S OVER THIS PERIOD. MPC && AVIATION.../ISSUED 1112 PM EST SAT MAR 8 2008/ A QUIET 24 HOURS COMING UP WITH LIGHT WINDS AND CLEAR SKIES. THE ONLY CLOUDS THAT WILL BE AROUND WILL BE SCT HIGH CLOUDS ABOVE 20000 FT OR SOME SCT LAKE CLOUDS AROUND 3500 FT. NO PRECIPITATION IS EXPECTED AT ANY OF THE TAF SITES DURING THE NEXT 24 HOURS. LUTZ && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. LH...NONE. && $$ mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1203 AM EST SUN MAR 9 2008 UPDATED FOR 06Z AVIATION .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD TROUGH OVER THE ERN CONUS WITH A MID LEVEL LOW OVER WV/OH ERN MANITOBA INTO NW MN. THIS LEFT UPPER MI BETWEEN THE TWO SYSTEMS WITH MID LEVEL AND SFC RIDGING. VIS SATELLITE AND RADAR SHOWED THAT THE COMBINATION OF VERY DRY AIR UPSTREAM AND DAYTIME HEATING/MIXING HAD HELPED REDUCE REMAINING ENE FLOW LAKE EFFECT SNOW SHOWERS TO ONLY A FEW FLURRIES VCNTY MARQUETTE. LIGHT SNOW ACROSS NW MN ASSOCIATED WITH THE MID LEVEL LOW AND SFC TROF SLIDING MAINLY TO THE SSE. && .SHORT TERM...(TONIGHT AND SUNDAY) EXPECT SOME INCREASE IN MID/UPPER LEVEL MOISTURE AS THE MID LEVEL LOW MOVES THROUGH MN. HOWEVER...SFC-700 MB MOISTURE WILL REMAIN SCARCE. RADIATIONAL COOLING WILL NOT BE QUITE AS FAVORABLE AS LAST NIGHT BUT STILL SHOULD ALLOW TEMPS TO DROP OFF TO -5 TO -10F INLAND WITH READINGS 0 TO 10F NEAR THE LAKE SUPERIOR N CNTRL. 850 MB TEMPS NEAR -16C...INCREASING ENE 950 WIND INTO THE 10 TO 20 KT RANGE ALONG WITH LAND BREEZE DEVELOPMENT SHOULD ALLOW LES TO REGENERATE WITH SOME SCT -SHSN INTO N CNTRL UPPER MI. HOWEVER...GIVEN THE VERY DRY LOW LEVEL AIR REMAINING AND GENERAL ACYC FLOW ANY ACCUMULATIONS SHOULD BE MINIMAL...UNDER AN INCH. LES MAY AGAIN BE POSSIBLE...MAINLY IN THE MORNING N CNTRL IN AREAS FAVORED BY ENE FLOW. SOME INCREASE IN LOW LEVEL MOISTURE ALONG WITH DIURNAL HEATING COULD LEAD TO A FEW FLURRIES IN ADDITION TO SCT-BKN SC INLAND. WITH NO ACCUMULATION EXPECTED...FCST DOES NOT INCLUDE POPS FOR NOW. .LONG TERM (SUNDAY NIGHT THROUGH NEXT SATURDAY)... RELATIVELY TRANQUIL FOR MUCH OF THE PERIOD. ALONG WITH A PERSISTENT WARM UP...STILL APPEARS THAT TWO MAIN NORTHERN BRANCH ORIGIN TROUGHS WILL AFFECT THE AREA WITH CHANCES FOR MAINLY LIGHT PCPN. AFTER A DRY MONDAY WITH TEMPERATURES WARMING BACK TOWARD NORMAL...CLOUDS WILL BE ON THE INCREASE MONDAY NIGHT. TROUGH APPEARS TO NOT DIG ENOUGH TO THE SOUTHWEST TO BRING MUCH PCPN INTO UPR MI. BETTER CHANCES FOR PCPN RESIDE OVR LK SUPERIOR CLOSER TO THE TRACK OF THE SHORTWAVE. BASED ON TRENDS FM 1000-850MB THICKNESSES FM GFS/ECMWF SCALED BACK THE CHANCE OF ANY RAIN ON TUE. SOUNDINGS SHOW A VERY SHALLOW WARM LAYER NEAR SFC...ESPECIALLY WHERE NW WINDS DOWNSLOPE IN SOUTH CENTRAL CWA. GRADUAL HEIGHT RISES FIRST COUPLE DAYS OF THE WEEK ARE REPLACED BY MUCH MORE SIGNIFICANT HEIGHT RISES/WARM AIR ADVECTION ON WED. GFS NOW JOINS EARLIER RUNS OF ECMWF/UKMET/CANADIAN IN TRENDING MUCH SHARPER WITH TROUGH DEVELOPING OVR NORTHERN PLAINS BY 00Z THU. 1000-500MB THICKNESSES ABOVE 540DAM...H9 TEMPS NEAR ZERO...AND INCREASING SOUTH WINDS AHEAD OF LOW PRESSURE TROUGH SUPPORT TEMPS INTO THE MID-UPR 30S. TRICK TO FORECAST THEN ARRIVES WED NIGHT AS PCPN DRIVEN BY RIGHT ENTRANCE OF JET OVR ONTARIO AND ISENTROPIC LIFT WILL BE POISED TO CROSS THE REGION. GFS WARMER THAN ECMWF BUT ECMWF IS COOLER THAN 00Z RUN YDY. CONFIDENCE INCREASING THAT PCPN WILL OCCUR (LATEST ECMWF SHOWS QPF UP TO A HALF INCH 00Z THU THROUGH 00Z FRI)...BUT STILL UNCERTAINTY FOR EXPECTED PTYPE. EXPECT A MIX OF RAIN/SNOW...PERHAPS FOR THE ENTIRE TIME OR MAYBE AFTER A PERIOD OF SNOW INITIALLY ON WED NIGHT. IF TEMPS WARM AS EXPECTED ON WED...THEN NOT TOO CONCERNED WITH POTENTIAL FOR FREEZING RAIN AS IT WOULD NOT BE A CASE OF AN ELEVATED WARM LAYER JUST A RAIN OR SNOW QUESTION BASED ON THE TEMPERATURE IN THE BLYR. TIMING AND EXACT PTYPE WILL LIKELY CHANGE BEFORE WED NIGHT AS MODELS HAVE NOT HONED IN ON EXACT IDEA QUITE YET. PCPN TAPERS OFF THU NIGHT ONCE TEMPS BECOME SUFFICIENTLY COLDER FOR JUST SNOW. TROUGH WITH MARGINALLY COLD AIR FOR DIURNAL AND/OR LK EFFECT SNOW SHOWERS REMAINS OVER THE GREAT LAKES FRIDAY INTO SATURDAY. SO...AFTER A BRIEF WARMING TREND THE MIDDLE OF THIS WEEK...TEMPS WILL RETURN TO NORMAL OR SLIGHTLY BLO NORMAL VALUES BY NEXT WEEKEND. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... LAKE EFFECT SNOW WILL CONTINUE A WHILE LONGER AT KSAW OVERNIGHT WITH NE FLOW OFF THE LAKE. WITH DRY AIR ON SUN...THINK VFR CONDITIONS WILL CONTINUE...BUT HAVE TO WORRY ABOUT MVFR CIGS POSSIBLY COMING IN FROM THE LAKE WITH NE FLOW AND POSSIBLE UPSLOPE. WILL GO WITH THE DRY AIR WINNING OUT AND KEEPING IT VFR FOR NOW. MVFR CIGS WILL MOVE BACK INTO KCMX WITH EAST WIND LATE TONIGHT...THEN AS THE WIND BECOMES LIGHT AND VAR LATE SUN...SHOULD GO BACK TO VFR. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... HEAVY FREEZING SPRAY WILL CONTINUE TONIGHT OVER EASTERN LAKE SUPERIOR AS NORTHEAST WINDS INCREASE INTO THE 15 TO 25 KNOT RANGE IN A TIGHTENING GRADIENT BTWN HIGH PRESSURE OVER NORTHERN ONTARIO AND A TROUGH INTO LOWER MI. THE HIGH SHOULD SHIFT TO OUR SOUTH ON MONDAY...MAKING WAY FOR A 29.8 INCH LOW OVER CENTRAL MANITOBA MONDAY NIGHT TO MOVE INTO NORTHERN ONTARIO TUESDAY. THE LOW WILL BRING INCREASED WRLY WINDS...UP TO 30 KNOTS. HIGH PRESSURE OF 30.0 INCHES WILL BRIEFLY TAKE OVER TUESDAY NIGHT AND WEDNESDAY...AS A 29.5 INCH LOW DEVELOPS OVER MANITOBA. && UPPER MICHIGAN...NONE. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING THROUGH 8 AM EDT SUNDAY FOR LSZ267. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/SHORT TERM...JLB LONG TERM...JLA AVIATION...GJM MARINE...JLB mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 630 PM EST SAT MAR 8 2008 UPDATED FOR 00Z AVIATION .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD TROUGH OVER THE ERN CONUS WITH A MID LEVEL LOW OVER WV/OH ERN MANITOBA INTO NW MN. THIS LEFT UPPER MI BETWEEN THE TWO SYSTEMS WITH MID LEVEL AND SFC RIDGING. VIS SATELLITE AND RADAR SHOWED THAT THE COMBINATION OF VERY DRY AIR UPSTREAM AND DAYTIME HEATING/MIXING HAD HELPED REDUCE REMAINING ENE FLOW LAKE EFFECT SNOW SHOWERS TO ONLY A FEW FLURRIES VCNTY MARQUETTE. LIGHT SNOW ACROSS NW MN ASSOCIATED WITH THE MID LEVEL LOW AND SFC TROF SLIDING MAINLY TO THE SSE. && .SHORT TERM...(TONIGHT AND SUNDAY) EXPECT SOME INCREASE IN MID/UPPER LEVEL MOISTURE AS THE MID LEVEL LOW MOVES THROUGH MN. HOWEVER...SFC-700 MB MOISTURE WILL REMAIN SCARCE. RADIATIONAL COOLING WILL NOT BE QUITE AS FAVORABLE AS LAST NIGHT BUT STILL SHOULD ALLOW TEMPS TO DROP OFF TO -5 TO -10F INLAND WITH READINGS 0 TO 10F NEAR THE LAKE SUPERIOR N CNTRL. 850 MB TEMPS NEAR -16C...INCREASING ENE 950 WIND INTO THE 10 TO 20 KT RANGE ALONG WITH LAND BREEZE DEVELOPMENT SHOULD ALLOW LES TO REGENERATE WITH SOME SCT -SHSN INTO N CNTRL UPPER MI. HOWEVER...GIVEN THE VERY DRY LOW LEVEL AIR REMAINING AND GENERAL ACYC FLOW ANY ACCUMULATIONS SHOULD BE MINIMAL...UNDER AN INCH. LES MAY AGAIN BE POSSIBLE...MAINLY IN THE MORNING N CNTRL IN AREAS FAVORED BY ENE FLOW. SOME INCREASE IN LOW LEVEL MOISTURE ALONG WITH DIURNAL HEATING COULD LEAD TO A FEW FLURRIES IN ADDITION TO SCT-BKN SC INLAND. WITH NO ACCUMULATION EXPECTED...FCST DOES NOT INCLUDE POPS FOR NOW. .LONG TERM (SUNDAY NIGHT THROUGH NEXT SATURDAY)... RELATIVELY TRANQUIL FOR MUCH OF THE PERIOD. ALONG WITH A PERSISTENT WARM UP...STILL APPEARS THAT TWO MAIN NORTHERN BRANCH ORIGIN TROUGHS WILL AFFECT THE AREA WITH CHANCES FOR MAINLY LIGHT PCPN. AFTER A DRY MONDAY WITH TEMPERATURES WARMING BACK TOWARD NORMAL...CLOUDS WILL BE ON THE INCREASE MONDAY NIGHT. TROUGH APPEARS TO NOT DIG ENOUGH TO THE SOUTHWEST TO BRING MUCH PCPN INTO UPR MI. BETTER CHANCES FOR PCPN RESIDE OVR LK SUPERIOR CLOSER TO THE TRACK OF THE SHORTWAVE. BASED ON TRENDS FM 1000-850MB THICKNESSES FM GFS/ECMWF SCALED BACK THE CHANCE OF ANY RAIN ON TUE. SOUNDINGS SHOW A VERY SHALLOW WARM LAYER NEAR SFC...ESPECIALLY WHERE NW WINDS DOWNSLOPE IN SOUTH CENTRAL CWA. GRADUAL HEIGHT RISES FIRST COUPLE DAYS OF THE WEEK ARE REPLACED BY MUCH MORE SIGNIFICANT HEIGHT RISES/WARM AIR ADVECTION ON WED. GFS NOW JOINS EARLIER RUNS OF ECMWF/UKMET/CANADIAN IN TRENDING MUCH SHARPER WITH TROUGH DEVELOPING OVR NORTHERN PLAINS BY 00Z THU. 1000-500MB THICKNESSES ABOVE 540DAM...H9 TEMPS NEAR ZERO...AND INCREASING SOUTH WINDS AHEAD OF LOW PRESSURE TROUGH SUPPORT TEMPS INTO THE MID-UPR 30S. TRICK TO FORECAST THEN ARRIVES WED NIGHT AS PCPN DRIVEN BY RIGHT ENTRANCE OF JET OVR ONTARIO AND ISENTROPIC LIFT WILL BE POISED TO CROSS THE REGION. GFS WARMER THAN ECMWF BUT ECMWF IS COOLER THAN 00Z RUN YDY. CONFIDENCE INCREASING THAT PCPN WILL OCCUR (LATEST ECMWF SHOWS QPF UP TO A HALF INCH 00Z THU THROUGH 00Z FRI)...BUT STILL UNCERTAINTY FOR EXPECTED PTYPE. EXPECT A MIX OF RAIN/SNOW...PERHAPS FOR THE ENTIRE TIME OR MAYBE AFTER A PERIOD OF SNOW INITIALLY ON WED NIGHT. IF TEMPS WARM AS EXPECTED ON WED...THEN NOT TOO CONCERNED WITH POTENTIAL FOR FREEZING RAIN AS IT WOULD NOT BE A CASE OF AN ELEVATED WARM LAYER JUST A RAIN OR SNOW QUESTION BASED ON THE TEMPERATURE IN THE BLYR. TIMING AND EXACT PTYPE WILL LIKELY CHANGE BEFORE WED NIGHT AS MODELS HAVE NOT HONED IN ON EXACT IDEA QUITE YET. PCPN TAPERS OFF THU NIGHT ONCE TEMPS BECOME SUFFICIENTLY COLDER FOR JUST SNOW. TROUGH WITH MARGINALLY COLD AIR FOR DIURNAL AND/OR LK EFFECT SNOW SHOWERS REMAINS OVER THE GREAT LAKES FRIDAY INTO SATURDAY. SO...AFTER A BRIEF WARMING TREND THE MIDDLE OF THIS WEEK...TEMPS WILL RETURN TO NORMAL OR SLIGHTLY BLO NORMAL VALUES BY NEXT WEEKEND. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... MVFR CIGS SHOULD DISSIPATE THIS EVENING AS WINDS BECOME LIGHT AND LAKE EFFECT SNOW DIMINISHES. NE FLOW WILL PICK UP ENOUGH LATE TONIGHT INTO SUN MORNING FOR ADDITIONAL MVFR CIGS TO RETURN AND LAST THROUGH THE DAY. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... HEAVY FREEZING SPRAY WILL CONTINUE TONIGHT OVER EASTERN LAKE SUPERIOR AS NORTHEAST WINDS INCREASE INTO THE 15 TO 25 KNOT RANGE IN A TIGHTENING GRADIENT BTWN HIGH PRESSURE OVER NORTHERN ONTARIO AND A TROUGH INTO LOWER MI. THE HIGH SHOULD SHIFT TO OUR SOUTH ON MONDAY...MAKING WAY FOR A 29.8 INCH LOW OVER CENTRAL MANITOBA MONDAY NIGHT TO MOVE INTO NORTHERN ONTARIO TUESDAY. THE LOW WILL BRING INCREASED WRLY WINDS...UP TO 30 KNOTS. HIGH PRESSURE OF 30.0 INCHES WILL BRIEFLY TAKE OVER TUESDAY NIGHT AND WEDNESDAY...AS A 29.5 INCH LOW DEVELOPS OVER MANITOBA. && UPPER MICHIGAN...NONE. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING THROUGH 8 AM EDT SUNDAY FOR LSZ267. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/SHORT TERM...JLB LONG TERM...JLA AVIATION...TAG MARINE...JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 410 PM EST SAT MAR 8 2008 .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD TROUGH OVER THE ERN CONUS WITH A MID LEVEL LOW OVER WV/OH ERN MANITOBA INTO NW MN. THIS LEFT UPPER MI BETWEEN THE TWO SYSTEMS WITH MID LEVEL AND SFC RIDGING. VIS SATELLITE AND RADAR SHOWED THAT THE COMBINATION OF VERY DRY AIR UPSTREAM AND DAYTIME HEATING/MIXING HAD HELPED REDUCE REMAINING ENE FLOW LAKE EFFECT SNOW SHOWERS TO ONLY A FEW FLURRIES VCNTY MARQUETTE. LIGHT SNOW ACROSS NW MN ASSOCIATED WITH THE MID LEVEL LOW AND SFC TROF SLIDING MAINLY TO THE SSE. && .SHORT TERM...(TONIGHT AND SUNDAY) EXPECT SOME INCREASE IN MID/UPPER LEVEL MOISTURE AS THE MID LEVEL LOW MOVES THROUGH MN. HOWEVER...SFC-700 MB MOISTURE WILL REMAIN SCARCE. RADIATIONAL COOLING WILL NOT BE QUITE AS FAVORABLE AS LAST NIGHT BUT STILL SHOULD ALLOW TEMPS TO DROP OFF TO -5 TO -10F INLAND WITH READINGS 0 TO 10F NEAR THE LAKE SUPERIOR N CNTRL. 850 MB TEMPS NEAR -16C...INCREASING ENE 950 WIND INTO THE 10 TO 20 KT RANGE ALONG WITH LAND BREEZE DEVELOPMENT SHOULD ALLOW LES TO REGENERATE WITH SOME SCT -SHSN INTO N CNTRL UPPER MI. HOWEVER...GIVEN THE VERY DRY LOW LEVEL AIR REMAINING AND GENERAL ACYC FLOW ANY ACCUMULATIONS SHOULD BE MINIMAL...UNDER AN INCH. LES MAY AGAIN BE POSSIBLE...MAINLY IN THE MORNING N CNTRL IN AREAS FAVORED BY ENE FLOW. SOME INCREASE IN LOW LEVEL MOISTURE ALONG WITH DIURNAL HEATING COULD LEAD TO A FEW FLURRIES IN ADDITION TO SCT-BKN SC INLAND. WITH NO ACCUMULATION EXPECTED...FCST DOES NOT INCLUDE POPS FOR NOW. .LONG TERM (SUNDAY NIGHT THROUGH NEXT SATURDAY)... RELATIVELY TRANQUIL FOR MUCH OF THE PERIOD. ALONG WITH A PERSISTENT WARM UP...STILL APPEARS THAT TWO MAIN NORTHERN BRANCH ORIGIN TROUGHS WILL AFFECT THE AREA WITH CHANCES FOR MAINLY LIGHT PCPN. AFTER A DRY MONDAY WITH TEMPERATURES WARMING BACK TOWARD NORMAL...CLOUDS WILL BE ON THE INCREASE MONDAY NIGHT. TROUGH APPEARS TO NOT DIG ENOUGH TO THE SOUTHWEST TO BRING MUCH PCPN INTO UPR MI. BETTER CHANCES FOR PCPN RESIDE OVR LK SUPERIOR CLOSER TO THE TRACK OF THE SHORTWAVE. BASED ON TRENDS FM 1000-850MB THICKNESSES FM GFS/ECMWF SCALED BACK THE CHANCE OF ANY RAIN ON TUE. SOUNDINGS SHOW A VERY SHALLOW WARM LAYER NEAR SFC...ESPECIALLY WHERE NW WINDS DOWNSLOPE IN SOUTH CENTRAL CWA. GRADUAL HEIGHT RISES FIRST COUPLE DAYS OF THE WEEK ARE REPLACED BY MUCH MORE SIGNIFICANT HEIGHT RISES/WARM AIR ADVECTION ON WED. GFS NOW JOINS EARLIER RUNS OF ECMWF/UKMET/CANADIAN IN TRENDING MUCH SHARPER WITH TROUGH DEVELOPING OVR NORTHERN PLAINS BY 00Z THU. 1000-500MB THICKNESSES ABOVE 540DAM...H9 TEMPS NEAR ZERO...AND INCREASING SOUTH WINDS AHEAD OF LOW PRESSURE TROUGH SUPPORT TEMPS INTO THE MID-UPR 30S. TRICK TO FORECAST THEN ARRIVES WED NIGHT AS PCPN DRIVEN BY RIGHT ENTRANCE OF JET OVR ONTARIO AND ISENTROPIC LIFT WILL BE POISED TO CROSS THE REGION. GFS WARMER THAN ECMWF BUT ECMWF IS COOLER THAN 00Z RUN YDY. CONFIDENCE INCREASING THAT PCPN WILL OCCUR (LATEST ECMWF SHOWS QPF UP TO A HALF INCH 00Z THU THROUGH 00Z FRI)...BUT STILL UNCERTAINTY FOR EXPECTED PTYPE. EXPECT A MIX OF RAIN/SNOW...PERHAPS FOR THE ENTIRE TIME OR MAYBE AFTER A PERIOD OF SNOW INITIALLY ON WED NIGHT. IF TEMPS WARM AS EXPECTED ON WED...THEN NOT TOO CONCERNED WITH POTENTIAL FOR FREEZING RAIN AS IT WOULD NOT BE A CASE OF AN ELEVATED WARM LAYER JUST A RAIN OR SNOW QUESTION BASED ON THE TEMPERATURE IN THE BLYR. TIMING AND EXACT PTYPE WILL LIKELY CHANGE BEFORE WED NIGHT AS MODELS HAVE NOT HONED IN ON EXACT IDEA QUITE YET. PCPN TAPERS OFF THU NIGHT ONCE TEMPS BECOME SUFFICIENTLY COLDER FOR JUST SNOW. TROUGH WITH MARGINALLY COLD AIR FOR DIURNAL AND/OR LK EFFECT SNOW SHOWERS REMAINS OVER THE GREAT LAKES FRIDAY INTO SATURDAY. SO...AFTER A BRIEF WARMING TREND THE MIDDLE OF THIS WEEK...TEMPS WILL RETURN TO NORMAL OR SLIGHTLY BLO NORMAL VALUES BY NEXT WEEKEND. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... AT KSAW...MVFR CIG WITH DIRUNAL SC AIDED BY WEAK ADVECTION OF LAKE MOISTURE INTO THE AREA ON LIGHT NE WINDS WILL PERSIST MUCH OF THE AFTERNOON BUT SHOULD DISSIPATE THIS EVENING AS WINDS BECOME LIGHT. NE FLOW WILL PICK UP ENOUGH LATE TONIGHT INTO SUN MORNING FOR ADDITIONAL MVFR CIGS. VFR CONDITIONS WILL PREVAIL AT KCMX UNTIL EARLY SUNDAY WHEN SOME MVFR CIGS ARE EXPECTED AS LAKE MOISTURE PUSHES TOWARD THE AREA AS LOW LEVEL NE WINDS INCREASE SLIGHTLY. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... HEAVY FREEZING SPRAY WILL CONTINUE TONIGHT OVER EASTERN LAKE SUPERIOR AS NORTHEAST WINDS INCREASE INTO THE 15 TO 25 KNOT RANGE IN A TIGHTENING GRADIENT BTWN HIGH PRESSURE OVER NORTHERN ONTARIO AND A TROUGH INTO LOWER MI. THE HIGH SHOULD SHIFT TO OUR SOUTH ON MONDAY...MAKING WAY FOR A 29.8 INCH LOW OVER CENTRAL MANITOBA MONDAY NIGHT TO MOVE INTO NORTHERN ONTARIO TUESDAY. THE LOW WILL BRING INCREASED WRLY WINDS...UP TO 30 KNOTS. HIGH PRESSURE OF 30.0 INCHES WILL BRIEFLY TAKE OVER TUESDAY NIGHT AND WEDNESDAY...AS A 29.5 INCH LOW DEVELOPS OVER MANITOBA. && UPPER MICHIGAN...NONE. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING THROUGH 8 AM EDT SUNDAY FOR LSZ267. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/SHORT TERM...JLB LONG TERM...JLA AVIATION...JLB MARINE...JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1250 PM EST SAT MAR 8 2008 UPDATED FOR 18Z TAF ISSUANCE .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS INDICATED AN AMPLIFIED PATTERN WITH A MID LEVEL TROUGH AXIS FROM E OF HUDSON BAY THROUGH THE WRN GREAT LAKES INTO THE LOWER MISSISSIPPI VALLEY. AN UPSTREAM SHORTWAVE IN NW FLOW WAS DESCENDING SOUTH THROUGH MANITOBA INTO NORTH DAKOTA EARLY THIS MORNING. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY INTO WRN LAKE SUPERIOR AND WRN WI. WEAK NRLY LOW LEVEL FLOW AHEAD OF THE RIDGE AXIS COMBINED WITH 850 MB TEMPS AROUND -21C CONTINUED TO SUPPORT WEAK MULTIPLE WIND PARALLEL LES BANDS INTO ALGER-LUCE AND NRN SCHOOLCRAFT COUNTIES. VERY DRY AIR AND EXTENSIVE ICE COVER HAS LIMITED LES INTO NW UPPER MI WITH ONLY WEAK BANDS OVER THE KEWEENAW PENINSULA NORTH OF HOUGHTON PER IR SATELLITE LOOP. IDEAL RADIATIONAL COOLING CONDITIONS HAS ALLOWED TEMPS TO NOSEDIVE THIS MORNING. -24F TEMPS WERE REPORTED AT BOTH THE WAKEFIELD AND STONINGTON RAWS SITES WITHIN THE PAST HR WITH -19F AT THE NWS MQT. .DISCUSSION... MAIN FCST CONCERNS ARE LES TRENDS AND MIN TEMPS. WIDELY-SPACED AND WEAK LES BANDS OVER THE ERN AND NCNTRL COUNTIES OF THE FCST AREA WILL CONTINUE TO BE NEGATIVELY IMPACTED INTO SUNDAY BY ANTICYCLONIC N-NE FLOW AND VERY DRY AIR UPSTREAM. WILL KEEP CHC POPS IN FOR NCNTRL COUNTIES INTO SUNDAY BUT EXPECT ACCUMULATIONS TO BE LESS THAN INCH FOR ANY 12 HR PERIOD. DIURNAL HEATING AND VERY LIGHT WIND FIELD WILL ALSO FURTHER DISRUPT WEAK LES BANDS DURING THE DAYTIME. EVENTUALLY...TEMPS WARMING TO -13/-14C AT TOP OF THE INVERSION AND LIGHT WIND FIELD SHOULD ALLOW LES TO END BY SUN EVENING. CONTINUED RIDGING WILL KEEP THE FCST AREA DRY INTO MONDAY. TEMPS SLOWLY MODERATE OVER THE WEEKEND AS DAYTIME HIGHS REACH INTO THE UPPER TEENS TO AROUND 20F ON SATURDAY AND LOW TO MID 20S ON SUNDAY. WAA IN WRLY FLOW AHEAD OF NEXT CLIPPER SYSTEM WILL BRING HIGHS ON MONDAY INTO THE LOW 30S. DESPITE THE SLOWLY MODERATING AIRMASS...IDEAL RADIATIONAL COOLING WITH LIGHT WINDS...CLEAR SKIES AND LOW PCPN WATER VALUES AROUND .1 INCH OR LESS WILL ALLOW INLAND READINGS TO FALL INTO THE SINGLE DIGITS BLO ZERO SAT NIGHT AND SUN NIGHT. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... AT KSAW...MVFR CIG WITH DIRUNAL SC AIDED BY WEAK ADVECTION OF LAKE MOISTURE INTO THE AREA ON LIGHT NE WINDS WILL PERSIST MUCH OF THE AFTERNOON BUT SHOULD DISSIPATE THIS EVENING AS WINDS BECOME LIGHT. NE FLOW WILL PICK UP ENOUGH LATE TONIGHT INTO SUN MORNING FOR ADDITIONAL MVFR CIGS. VFR CONDITIONS WILL PREVAIL AT KCMX UNTIL EARLY SUNDAY WHEN SOME MVFR CIGS ARE EXPECTED AS LAKE MOISTURE PUSHES TOWARD THE AREA AS LOW LEVEL NE WINDS INCREASE SLIGHTLY. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... FREEZING SPRAY WILL REMAIN THE MAIN CONCERN AS A COLD AIRMASS REMAINS. A HIGH PRESSURE RIDGE AVERAGING 30.4 INCHES WILL DOMINATE THE GREAT LAKES AREA THROUGH THE WEEKEND....WITH LIGHT WINDS LESS THAN 20KTS EXPECTED. THIS HIGH SHOULD SHIFT TO OUR SOUTH ON MONDAY...MAKING WAY FOR A 29.8 INCH LOW OVER CENTRAL MANITOBA MONDAY NIGHT TO CROSS LAKE SUPERIOR TUESDAY. INCREASED WINDS MONDAY...BUT STILL BELOW 30KTS. HIGH PRESSURE OF 30.0 INCHES WILL BRIEFLY TAKE OVER TUESDAY NIGHT AND WEDNESDAY...AS A 29.5 INCH LOW DEVELOPS OVER MANITOBA. && UPPER MICHIGAN...NONE. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING FROM 7 PM EST THIS EVENING TO 8 AM EDT SUNDAY FOR LSZ267. LAKE MICHIGAN...NONE. && $$ SYNOPSIS...VOSS DISCUSSION...VOSS AVIATION...KF MARINE...KF mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1225 PM EST SAT MAR 8 2008 .AVIATION...PERSISTENT NORTHEAST WIND FLOW WILL CONTINUE TO PROVIDE PERIODIC MVFR CIGS/VISBYS FOR KAPN AS LIGHT LAKE EFFECT SNOW SHOWERS HEAD ONSHORE THROUGH MID AFTERNOON. HOWEVER...THINK OVERLAND MIXING WILL EVENTUALLY OVERCOME THIS...SO IMPROVING CONDITIONS EXPECTED...AIDED BY FLOW TURNING MORE NORTHERLY BY 00Z TONIGHT. FOR KTVC/KPLN...PLENTY OF DRY AIR IN PLACE AND NORTH/NORTHEAST DOWNSLOPING WIND FLOW WILL ENSURE A CONTINUATION OF MAINLY CLEAR SKIES INTO THE EVENING. FLOW EXPECTED TO TURN MORE NORTHWESTERLY OVERNIGHT...WHICH SHOULD BRING BACK THE STRATOCU TOWARD KTVC ALONG WITH PERHAPS A FEW FLURRIES...BUT OVERALL VERY DRY AIRMASS SHOULD HELP KEEP THINGS IN CHECK. LAWRENCE && .PREV DISCUSSION... /ISSUED 1003 AM EST SAT MAR 8 2008/ FEW CHANGES NEEDED TO GOING FCST...WITH YET ANOTHER MAINLY QUIET WX DAY ON TAP FOR NORTHERN MICHIGAN. CLOSED UPR LOW ADVANCING THRU CENTRAL KENTUCKY THIS MORNING WILL MAINTAIN WEAK MID LEVEL SHORTWAVE RIDGING OVR THE REGION INTO THE AFTN...AS ASSOCIATED SFC LOW TRACKS TOWARD SOUTHERN NEW YORK BY 00Z TONIGHT. THIS SHOULD HOLD THE LOW LEVEL FLOW REGIME OUT OF THE NORTHEAST THRU EARLY AFTN...BEFORE FLOW BACKS MORE NORTHERLY BY EVENING IN THE WAKE OF THIS SYSTEM. DESPITE OVERALL PATHETIC BOUNDARY LAYER MOISTURE PROFILES (900-700MB RH ONLY AROUND 25%)...DECENT TRAJECTORIES ACROSS LAKE HURON AND NEARLY PERFECT TEMP PROFILES (900-800MB TEMPS RUNNING RIGHT AROUND -15C) FOR SNOW GROWTH SHOULD MAINTAIN LIGHT SNOW SHOWERS/FLURRIES INTO THE AFTN ACROSS MAINLY NORTHEAST LOWER COUNTIES. IN FACT...EXPECT AN UPTICK IN FLURRIES THRU LATE MORNING/ EARLY AFTN AS GRADIENT TIGHTENS AND FLOW INCREASES (H85 WINDS PROGGED 20 KNOTS BY 18Z)...AIDING IN AN INCREASING MOISTURE FLUX FURTHER INTO THE HIGHER TERRAIN. COUPLED WITH MARCH SUNSHINE... SHOULD AGAIN SEE A STRATOCU RESPONSE BEFORE ENTRAINMENT OF VERY AIR PER 12Z APX RAOB LIKELY WINS OUT TO YIELD MOSTLY SUNNY CONDITIONS BY AFTN. AS FOR TEMPS... CERTAINLY ANOTHER COOL ONE FOR EARLY MARCH AS MODIFIED ARCTIC AIRMASS REMAINS FIRMLY ENTRENCHED OVER THE REGION...WITH H85 TEMPS AROUND -15C THRU THE DAY AND ANALOG TO YESTERDAY (WHEN H85 TEMPS JUST A HAIR COLDER) SUGGESTING HIGHS IN THE UPR TEENS HIGHER TERRAIN TO MID 20S NEAR THE COASTS. LAWRENCE DISCUSSION... /ISSUED 532 AM EST SAT MAR 8 2008/ UPDATE...A QUICK UPDATE TO REFLECT DEVELOPMENT OF LIGHT SNOW AND FLURRIES OVER THE HIGHER TERRAIN. MOISTURE FLUXES DUE TO NE FLOW OFF LAKE HURON COMBINED WITH UPSLOPE FLOW OVER NORTH CENTRAL LOWER HAS HELPED AN AREA OF LIGHT SNOW AND FLURRIES TO GENERATE OVER THE PAST HOUR OR SO. WITH LITTLE CHANGE IN CONDITIONS EXPECTED TO OCCUR...HAVE UPDATED GRIDS TO INCLUDE A CHANCE OF LIGHT SNOW AND FLURRIES FARTHER WEST THROUGH THE MORNING. LITTLE TO NO ACCUMULATIONS ARE EXPECTED. NEW ZONES OUT SHORTLY. MPC PREV DISCUSSION... /ISSUED 400 AM EST SAT MAR 8 2008/ DISCUSSION...03Z SURFACE/RUC ANALYSIS AND IR/WV/RADAR IMAGERY CONTINUE TO SHOW A AMPLIFIED PATTERN ACROSS NORTH AMERICA...WITH A WESTERN NOAM RIDGE AND A DEEP TROUGH RANGING FROM HUDSON BAY TO THE GREAT LAKES TO THE GULF COAST. CIRRUS SHIELD JUST AHEAD OF THE TROUGH AXIS WITHIN CONFLUENT MID-LEVEL FLOW CONTINUES TO SCRAPE BY THE SE CWA...WHILE SW-NE ORIENTATED SURFACE RIDGE AXIS IS SUPPLYING THE AREA WITH EXCEPTIONALLY DRY AIR (PWAT 0.06 IN) THAT HAS PREVENTED ANY PRECIP RELATED FROM THE POTENT STORM OVER THE MID-ATLANTIC REGION FROM REACHING THIS FAR NORTH. HOWEVER...THIS SURFACE HIGH IS ALSO PROVIDING THE AREA WITH AN ARCTIC AIRMASS (850MB TEMP -19C) AND INSTABILITY NEEDED TO GENERATE LAKE EFFECT SNOW (LES). THIS SNOW HAS BEEN MOSTLY CONFINED TO AREAS ALONG THE WEST ARM OF GRAND TRAVERSE BAY AND THE LEELANAU PENINSULA AND WHITEFISH POINT...BUT LITTLE IN THE WAY OF ACTIVITY ALONG THE LAKE HURON SHORELINE. WITH THE MODELS IN GOOD AGREEMENT THAT THE EAST COAST STORM WILL PASS WELL EAST OF THE AREA...LIGHT LAKE EFFECT PRECIP IS THE MAIN CONCERN OVER THE NEXT 24 HOURS. TODAY...POTENT MID-ATLANTIC STORM WILL STRENGTHEN FURTHER AS IT MOVES TOWARDS NEW ENGLAND BY THIS EVENING. AS THE PRESSURE GRADIENT TIGHTENS A BIT...LOW LEVEL WINDS WILL SHIFT FROM THE NORTH TO NE THROUGH MIDDAY...THEN BACK TO THE NORTH BY EARLY THIS EVENING. ALTHOUGH 850MB TEMPS MODERATE FROM THE UPPER NEG TEENS TO THE MID NEG TEENS...LOW-MID LEVEL WIND TRAJECTORIES ORIGINATE FROM A HUDSON BAY HIGH WHICH WILL MAINTAIN VERY DRY AIR (850-700MB RH 15-25 PCT) ACROSS NORTHERN MICHIGAN. THIS DRY AIR WILL KEEP A CAP ON LES POTENTIAL OFF LAKE HURON DESPITE THE REASONABLY LONG FETCHES. AS A RESULT...LOW CHANCY POPS ARE STILL WARRANTED FOR THE MORNING FROM ALPENA TO TAWAS BEFORE DIURNAL MIXING AND BACKING WINDS HELP TO DIMINISH LES ACTIVITY DURING THE AFTERNOON. LITTLE TO NO ACCUMULATIONS ARE EXPECTED. OTHERWISE...ACROSS THE REMAINDER OF NORTHERN MICHIGAN...LOOK FOR PLENTY OF SUNSHINE TO BE HAD...ESPECIALLY ACROSS DOWNSLOPING AREAS OF NW LOWER AND EASTERN UPPER. UPSLOPE FLOW ALONG WITH MOISTURE FLUX OFF HURON WILL HELP DIURNAL CU FORM OVER THE EASTERN FRINGES OF THE HIGHER TERRAIN...BUT THINK MIXING WILL ERODE THIS CLOUD COVER TOWARDS MID AND LATE AFTERNOON. HIGHS WILL RANGE FROM THE UPPER TEENS NORTH TO MID 20S SOUTH. TONIGHT...SURFACE HIGH PRESSURE WILL REMAIN THE DOMINANT FEATURE WHICH WOULD PLACE NORTHERN MICHIGAN BETWEEN THE DEEP LOW TO OUR EAST...AND A SHORTWAVE TROUGH TO OUR WEST. THIS LATTER FEATURE WILL SLIDE FROM THE UPPER GREAT PLAINS TO THE SOUTHERN MN/WISCONSIN BORDER AND WILL SPREAD UPPER LEVEL MOISTURE ACROSS THE AREA. HOWEVER...VERY DRY LOW/MID LEVEL AIR (850-700MB RH 10-20 PCT) WILL REMAIN ACROSS THE AREA WHILE ALL ISENTROPIC ASCENT WILL RESIDE TO OUR SW. THIS WILL KEEP ALL SYNOPTIC PRECIP AWAY FROM THE REGION...WHICH LEAVES LAKE EFFECT PROCESSES AS THE PRIMARY SNOW CHANCE. 850MB TEMPS WILL HOLD STEADY AROUND -15C AND CYCLONIC LOW LEVEL FLOW WILL REMAIN IN PLACE. GIVEN THE OVERWHELMING DRY AIR IN PLACE...HARD TO IMAGINE ANYTHING MORE THAN FLURRIES ALONG THE LAKE MICHIGAN SHORELINE AND NEAR APN AS WIND BECOME LOCKED IN THE NNW DIRECTION. ADDITIONALLY...GIVEN THE EXPECTED THINNESS OF THE CIRRUS...DO NOT BELIEVE THE CLOUD COVER WILL HAVE MUCH OF AN IMPACT ON LOW TEMPS OUTSIDE OF THE SW CWA. THEREFORE...THE TYPICAL COLD SPOTS ACROSS EASTERN UPPER AND NE LOWER STILL LOOK TO GO BELOW ZERO ONCE AGAIN. SUNDAY AND SUNDAY NIGHT...VERY LITTLE TO CHANGE OVER THESE PERIODS. SHORTWAVE TROUGH AND ASSOCIATED FORCING WILL PIVOT ACROSS THE SOUTHERN GREAT LAKES AND NORTHERN OHIO RIVER VALLEY...WHILE HIGH PRESSURE WILL CONTINUE ITS DOMINANCE OVER THE NORTHERN GREAT LAKES. 850MB TEMPS DO MODERATE A COUPLE DEGREES BY SUNDAY AFTERNOON WHILE VERY DRY AIR (850-700MB RH 10-20 PCT) WILL REMAIN PRESENT. WILL KEEP A CHANCE OF FLURRIES DURING THE MORNING AROUND THE GTV BAY REGION AND VICINITY BEFORE NNW WINDS SUBSIDE TO 10KTS OR LESS AS THE PRESSURE GRADIENT SLACKENS. OUTSIDE OF SOME HIGH CLOUDS...ANOTHER NICE DAY WITH TEMPS IN THE LOWER TO MID 20S. COULD BE ANOTHER GOOD RADIATIONAL COOLING NIGHT IF THE HIGH CLOUDS DISSIPATE. WILL LOWER TEMPS A FEW DEGREES SINCE BELIEVE THE HIGH CLOUDS WONT IMPACT THE COOLING CURVE THAT MUCH. MONDAY THROUGH WEDNESDAY...POSITIVE PNA PATTERN FINALLY BREAKS DOWN DURING THIS PERIODS AS A BARRAGE OF PACIFIC SHORTWAVES WITHIN FAST ZONAL FLOW BEAT DOWN THE WESTERN NOAM RIDGE. AS A RESULT...WARMER AIR OF PACIFIC ORIGIN WILL TRY TO WARM THE TEMPERATURES ACROSS THE GREAT LAKES CLOSER TO THE NORM. FIRST OF THE PACIFIC WAVES IS DUE TO PASS OVER THE NORTHERN GREAT LAKES ON TUESDAY. GFS BRINGS A MORE SOUTHERLY TRACK WITH THIS WAVE...WHICH WOULD PROVIDE NORTHERN MICHIGAN WITH PRECIP...WHILE THE ECMWF KEEPS THE FORCING NORTH OF THE AREA. WILL KEEP CONTINUITY FOR NOW. REGARDLESS...FORCING AND MOISTURE ARE LESS THAN IMPRESSIVE AND IT DOESNT LOOK TO BE A BIG DEAL. OUTSIDE OF THIS SYSTEM...MONDAY AND WEDNESDAY LOOK DRY. MPC && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. LH...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR LHZ348-349. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1003 AM EST SAT MAR 8 2008 .UPDATE...FEW CHANGES NEEDED TO GOING FCST...WITH YET ANOTHER MAINLY QUIET WX DAY ON TAP FOR NORTHERN MICHIGAN. CLOSED UPR LOW ADVANCING THRU CENTRAL KENTUCKY THIS MORNING WILL MAINTAIN WEAK MID LEVEL SHORTWAVE RIDGING OVR THE REGION INTO THE AFTN...AS ASSOCIATED SFC LOW TRACKS TOWARD SOUTHERN NEW YORK BY 00Z TONIGHT. THIS SHOULD HOLD THE LOW LEVEL FLOW REGIME OUT OF THE NORTHEAST THRU EARLY AFTN...BEFORE FLOW BACKS MORE NORTHERLY BY EVENING IN THE WAKE OF THIS SYSTEM. DESPITE OVERALL PATHETIC BOUNDARY LAYER MOISTURE PROFILES (900-700MB RH ONLY AROUND 25%)...DECENT TRAJECTORIES ACROSS LAKE HURON AND NEARLY PERFECT TEMP PROFILES (900-800MB TEMPS RUNNING RIGHT AROUND -15C) FOR SNOW GROWTH SHOULD MAINTAIN LIGHT SNOW SHOWERS/FLURRIES INTO THE AFTN ACROSS MAINLY NORTHEAST LOWER COUNTIES. IN FACT...EXPECT AN UPTICK IN FLURRIES THRU LATE MORNING/ EARLY AFTN AS GRADIENT TIGHTENS AND FLOW INCREASES (H85 WINDS PROGGED 20 KNOTS BY 18Z)...AIDING IN AN INCREASING MOISTURE FLUX FURTHER INTO THE HIGHER TERRAIN. COUPLED WITH MARCH SUNSHINE... SHOULD AGAIN SEE A STRATOCU RESPONSE BEFORE ENTRAINMENT OF VERY AIR PER 12Z APX RAOB LIKELY WINS OUT TO YIELD MOSTLY SUNNY CONDITIONS BY AFTN. AS FOR TEMPS... CERTAINLY ANOTHER COOL ONE FOR EARLY MARCH AS MODIFIED ARCTIC AIRMASS REMAINS FIRMLY ENTRENCHED OVER THE REGION...WITH H85 TEMPS AROUND -15C THRU THE DAY AND ANALOG TO YESTERDAY (WHEN H85 TEMPS JUST A HAIR COLDER) SUGGESTING HIGHS IN THE UPR TEENS HIGHER TERRAIN TO MID 20S NEAR THE COASTS. LAWRENCE && .AVIATION... /ISSUED 605 AM EST SAT MAR 8 2008/ NE WINDS OFF LAKE HURON WILL KEEP MVFR CIGS AND LIGHT SNOW SHOWER ACTIVITY THROUGH THIS MORNING FOR APN...BEFORE MIXING WILL PROVIDE MORE BREAKS IN THE CLOUDS THIS AFTERNOON. MVFR DECK AT PLN SHOULD BE TEMPORARY DUE TO THE LIMITED FETCH OFF LAKE HURON AND THE DRIER DRAINAGE FLOW OUT OF ONTARIO POSSIBLY MOVING IN...AND WILL RETURN VFR CONDITIONS AN HOUR OR TWO AFTER TAF ISSUANCE. TVC LOOKS TO BE IN THE CLEAR UNTIL LATE THIS AFTERNOON WHEN WINDS SHIFT TO THE NW AND BRINGS LAKE CLOUDS INLAND. HOWEVER...THINK CIGS WILL REMAIN VFR THROUGH THE TAF PERIOD FOR TVC. MPC && PREV DISCUSSION... /ISSUED 532 AM EST SAT MAR 8 2008/ UPDATE...A QUICK UPDATE TO REFLECT DEVELOPMENT OF LIGHT SNOW AND FLURRIES OVER THE HIGHER TERRAIN. MOISTURE FLUXES DUE TO NE FLOW OFF LAKE HURON COMBINED WITH UPSLOPE FLOW OVER NORTH CENTRAL LOWER HAS HELPED AN AREA OF LIGHT SNOW AND FLURRIES TO GENERATE OVER THE PAST HOUR OR SO. WITH LITTLE CHANGE IN CONDITIONS EXPECTED TO OCCUR...HAVE UPDATED GRIDS TO INCLUDE A CHANCE OF LIGHT SNOW AND FLURRIES FARTHER WEST THROUGH THE MORNING. LITTLE TO NO ACCUMULATIONS ARE EXPECTED. NEW ZONES OUT SHORTLY. MPC PREV DISCUSSION... /ISSUED 400 AM EST SAT MAR 8 2008/ DISCUSSION...03Z SURFACE/RUC ANALYSIS AND IR/WV/RADAR IMAGERY CONTINUE TO SHOW A AMPLIFIED PATTERN ACROSS NORTH AMERICA...WITH A WESTERN NOAM RIDGE AND A DEEP TROUGH RANGING FROM HUDSON BAY TO THE GREAT LAKES TO THE GULF COAST. CIRRUS SHIELD JUST AHEAD OF THE TROUGH AXIS WITHIN CONFLUENT MID-LEVEL FLOW CONTINUES TO SCRAPE BY THE SE CWA...WHILE SW-NE ORIENTATED SURFACE RIDGE AXIS IS SUPPLYING THE AREA WITH EXCEPTIONALLY DRY AIR (PWAT 0.06 IN) THAT HAS PREVENTED ANY PRECIP RELATED FROM THE POTENT STORM OVER THE MID-ATLANTIC REGION FROM REACHING THIS FAR NORTH. HOWEVER...THIS SURFACE HIGH IS ALSO PROVIDING THE AREA WITH AN ARCTIC AIRMASS (850MB TEMP -19C) AND INSTABILITY NEEDED TO GENERATE LAKE EFFECT SNOW (LES). THIS SNOW HAS BEEN MOSTLY CONFINED TO AREAS ALONG THE WEST ARM OF GRAND TRAVERSE BAY AND THE LEELANAU PENINSULA AND WHITEFISH POINT...BUT LITTLE IN THE WAY OF ACTIVITY ALONG THE LAKE HURON SHORELINE. WITH THE MODELS IN GOOD AGREEMENT THAT THE EAST COAST STORM WILL PASS WELL EAST OF THE AREA...LIGHT LAKE EFFECT PRECIP IS THE MAIN CONCERN OVER THE NEXT 24 HOURS. TODAY...POTENT MID-ATLANTIC STORM WILL STRENGTHEN FURTHER AS IT MOVES TOWARDS NEW ENGLAND BY THIS EVENING. AS THE PRESSURE GRADIENT TIGHTENS A BIT...LOW LEVEL WINDS WILL SHIFT FROM THE NORTH TO NE THROUGH MIDDAY...THEN BACK TO THE NORTH BY EARLY THIS EVENING. ALTHOUGH 850MB TEMPS MODERATE FROM THE UPPER NEG TEENS TO THE MID NEG TEENS...LOW-MID LEVEL WIND TRAJECTORIES ORIGINATE FROM A HUDSON BAY HIGH WHICH WILL MAINTAIN VERY DRY AIR (850-700MB RH 15-25 PCT) ACROSS NORTHERN MICHIGAN. THIS DRY AIR WILL KEEP A CAP ON LES POTENTIAL OFF LAKE HURON DESPITE THE REASONABLY LONG FETCHES. AS A RESULT...LOW CHANCY POPS ARE STILL WARRANTED FOR THE MORNING FROM ALPENA TO TAWAS BEFORE DIURNAL MIXING AND BACKING WINDS HELP TO DIMINISH LES ACTIVITY DURING THE AFTERNOON. LITTLE TO NO ACCUMULATIONS ARE EXPECTED. OTHERWISE...ACROSS THE REMAINDER OF NORTHERN MICHIGAN...LOOK FOR PLENTY OF SUNSHINE TO BE HAD...ESPECIALLY ACROSS DOWNSLOPING AREAS OF NW LOWER AND EASTERN UPPER. UPSLOPE FLOW ALONG WITH MOISTURE FLUX OFF HURON WILL HELP DIURNAL CU FORM OVER THE EASTERN FRINGES OF THE HIGHER TERRAIN...BUT THINK MIXING WILL ERODE THIS CLOUD COVER TOWARDS MID AND LATE AFTERNOON. HIGHS WILL RANGE FROM THE UPPER TEENS NORTH TO MID 20S SOUTH. TONIGHT...SURFACE HIGH PRESSURE WILL REMAIN THE DOMINANT FEATURE WHICH WOULD PLACE NORTHERN MICHIGAN BETWEEN THE DEEP LOW TO OUR EAST...AND A SHORTWAVE TROUGH TO OUR WEST. THIS LATTER FEATURE WILL SLIDE FROM THE UPPER GREAT PLAINS TO THE SOUTHERN MN/WISCONSIN BORDER AND WILL SPREAD UPPER LEVEL MOISTURE ACROSS THE AREA. HOWEVER...VERY DRY LOW/MID LEVEL AIR (850-700MB RH 10-20 PCT) WILL REMAIN ACROSS THE AREA WHILE ALL ISENTROPIC ASCENT WILL RESIDE TO OUR SW. THIS WILL KEEP ALL SYNOPTIC PRECIP AWAY FROM THE REGION...WHICH LEAVES LAKE EFFECT PROCESSES AS THE PRIMARY SNOW CHANCE. 850MB TEMPS WILL HOLD STEADY AROUND -15C AND CYCLONIC LOW LEVEL FLOW WILL REMAIN IN PLACE. GIVEN THE OVERWHELMING DRY AIR IN PLACE...HARD TO IMAGINE ANYTHING MORE THAN FLURRIES ALONG THE LAKE MICHIGAN SHORELINE AND NEAR APN AS WIND BECOME LOCKED IN THE NNW DIRECTION. ADDITIONALLY...GIVEN THE EXPECTED THINNESS OF THE CIRRUS...DO NOT BELIEVE THE CLOUD COVER WILL HAVE MUCH OF AN IMPACT ON LOW TEMPS OUTSIDE OF THE SW CWA. THEREFORE...THE TYPICAL COLD SPOTS ACROSS EASTERN UPPER AND NE LOWER STILL LOOK TO GO BELOW ZERO ONCE AGAIN. SUNDAY AND SUNDAY NIGHT...VERY LITTLE TO CHANGE OVER THESE PERIODS. SHORTWAVE TROUGH AND ASSOCIATED FORCING WILL PIVOT ACROSS THE SOUTHERN GREAT LAKES AND NORTHERN OHIO RIVER VALLEY...WHILE HIGH PRESSURE WILL CONTINUE ITS DOMINANCE OVER THE NORTHERN GREAT LAKES. 850MB TEMPS DO MODERATE A COUPLE DEGREES BY SUNDAY AFTERNOON WHILE VERY DRY AIR (850-700MB RH 10-20 PCT) WILL REMAIN PRESENT. WILL KEEP A CHANCE OF FLURRIES DURING THE MORNING AROUND THE GTV BAY REGION AND VICINITY BEFORE NNW WINDS SUBSIDE TO 10KTS OR LESS AS THE PRESSURE GRADIENT SLACKENS. OUTSIDE OF SOME HIGH CLOUDS...ANOTHER NICE DAY WITH TEMPS IN THE LOWER TO MID 20S. COULD BE ANOTHER GOOD RADIATIONAL COOLING NIGHT IF THE HIGH CLOUDS DISSIPATE. WILL LOWER TEMPS A FEW DEGREES SINCE BELIEVE THE HIGH CLOUDS WONT IMPACT THE COOLING CURVE THAT MUCH. MONDAY THROUGH WEDNESDAY...POSITIVE PNA PATTERN FINALLY BREAKS DOWN DURING THIS PERIODS AS A BARRAGE OF PACIFIC SHORTWAVES WITHIN FAST ZONAL FLOW BEAT DOWN THE WESTERN NOAM RIDGE. AS A RESULT...WARMER AIR OF PACIFIC ORIGIN WILL TRY TO WARM THE TEMPERATURES ACROSS THE GREAT LAKES CLOSER TO THE NORM. FIRST OF THE PACIFIC WAVES IS DUE TO PASS OVER THE NORTHERN GREAT LAKES ON TUESDAY. GFS BRINGS A MORE SOUTHERLY TRACK WITH THIS WAVE...WHICH WOULD PROVIDE NORTHERN MICHIGAN WITH PRECIP...WHILE THE ECMWF KEEPS THE FORCING NORTH OF THE AREA. WILL KEEP CONTINUITY FOR NOW. REGARDLESS...FORCING AND MOISTURE ARE LESS THAN IMPRESSIVE AND IT DOESNT LOOK TO BE A BIG DEAL. OUTSIDE OF THIS SYSTEM...MONDAY AND WEDNESDAY LOOK DRY. MPC && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. LH...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR LHZ348-349. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 615 AM EST SAT MAR 8 2008 UPDATED FOR 12Z TAF ISSUANCE .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS INDICATED AN AMPLIFIED PATTERN WITH A MID LEVEL TROUGH AXIS FROM E OF HUDSON BAY THROUGH THE WRN GREAT LAKES INTO THE LOWER MISSISSIPPI VALLEY. AN UPSTREAM SHORTWAVE IN NW FLOW WAS DESCENDING SOUTH THROUGH MANITOBA INTO NORTH DAKOTA EARLY THIS MORNING. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY INTO WRN LAKE SUPERIOR AND WRN WI. WEAK NRLY LOW LEVEL FLOW AHEAD OF THE RIDGE AXIS COMBINED WITH 850 MB TEMPS AROUND -21C CONTINUED TO SUPPORT WEAK MULTIPLE WIND PARALLEL LES BANDS INTO ALGER-LUCE AND NRN SCHOOLCRAFT COUNTIES. VERY DRY AIR AND EXTENSIVE ICE COVER HAS LIMITED LES INTO NW UPPER MI WITH ONLY WEAK BANDS OVER THE KEWEENAW PENINSULA NORTH OF HOUGHTON PER IR SATELLITE LOOP. IDEAL RADIATIONAL COOLING CONDITIONS HAS ALLOWED TEMPS TO NOSEDIVE THIS MORNING. -24F TEMPS WERE REPORTED AT BOTH THE WAKEFIELD AND STONINGTON RAWS SITES WITHIN THE PAST HR WITH -19F AT THE NWS MQT. .DISCUSSION... MAIN FCST CONCERNS ARE LES TRENDS AND MIN TEMPS. WIDELY-SPACED AND WEAK LES BANDS OVER THE ERN AND NCNTRL COUNTIES OF THE FCST AREA WILL CONTINUE TO BE NEGATIVELY IMPACTED INTO SUNDAY BY ANTICYCLONIC N-NE FLOW AND VERY DRY AIR UPSTREAM. WILL KEEP CHC POPS IN FOR NCNTRL COUNTIES INTO SUNDAY BUT EXPECT ACCUMULATIONS TO BE LESS THAN INCH FOR ANY 12 HR PERIOD. DIURNAL HEATING AND VERY LIGHT WIND FIELD WILL ALSO FURTHER DISRUPT WEAK LES BANDS DURING THE DAYTIME. EVENTUALLY...TEMPS WARMING TO -13/-14C AT TOP OF THE INVERSION AND LIGHT WIND FIELD SHOULD ALLOW LES TO END BY SUN EVENING. CONTINUED RIDGING WILL KEEP THE FCST AREA DRY INTO MONDAY. TEMPS SLOWLY MODERATE OVER THE WEEKEND AS DAYTIME HIGHS REACH INTO THE UPPER TEENS TO AROUND 20F ON SATURDAY AND LOW TO MID 20S ON SUNDAY. WAA IN WRLY FLOW AHEAD OF NEXT CLIPPER SYSTEM WILL BRING HIGHS ON MONDAY INTO THE LOW 30S. DESPITE THE SLOWLY MODERATING AIRMASS...IDEAL RADIATIONAL COOLING WITH LIGHT WINDS...CLEAR SKIES AND LOW PCPN WATER VALUES AROUND .1 INCH OR LESS WILL ALLOW INLAND READINGS TO FALL INTO THE SINGLE DIGITS BLO ZERO SAT NIGHT AND SUN NIGHT. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... VFR CEIGS AND VIS WILL DOMINATE FOR THE MOST PART. NORTHERLY WINDS WILL ASSIST IN BRINGING SMALL BANDS OF LES TO THE REGION. HOWEVER...A STEADY DIRECTION WILL BE DIFFICULT TO COME BY...LEADING TO SHIFTING LES POSSIBLY BREAKING UP A LITTLE MORE THAN SHOWN OF THE CURRENT RADAR IMG. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... FREEZING SPRAY WILL REMAIN THE MAIN CONCERN AS A COLD AIRMASS REMAINS. A HIGH PRESSURE RIDGE AVERAGING 30.4 INCHES WILL DOMINATE THE GREAT LAKES AREA THROUGH THE WEEKEND....WITH LIGHT WINDS LESS THAN 20KTS EXPECTED. THIS HIGH SHOULD SHIFT TO OUR SOUTH ON MONDAY...MAKING WAY FOR A 29.8 INCH LOW OVER CENTRAL MANITOBA MONDAY NIGHT TO CROSS LAKE SUPERIOR TUESDAY. INCREASED WINDS MONDAY...BUT STILL BELOW 30KTS. HIGH PRESSURE OF 30.0 INCHES WILL BRIEFLY TAKE OVER TUESDAY NIGHT AND WEDNESDAY...AS A 29.5 INCH LOW DEVELOPS OVER MANITOBA. && UPPER MICHIGAN...NONE. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING FROM 7 PM EST THIS EVENING TO 8 AM EDT SUNDAY FOR LSZ267. LAKE MICHIGAN...NONE. && $$ SYNOPSIS...VOSS DISCUSSION...VOSS AVIATION...KF MARINE...KF mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 605 AM EST SAT MAR 8 2008 .AVIATION...NE WINDS OFF LAKE HURON WILL KEEP MVFR CIGS AND LIGHT SNOW SHOWER ACTIVITY THROUGH THIS MORNING FOR APN...BEFORE MIXING WILL PROVIDE MORE BREAKS IN THE CLOUDS THIS AFTERNOON. MVFR DECK AT PLN SHOULD BE TEMPORARY DUE TO THE LIMITED FETCH OFF LAKE HURON AND THE DRIER DRAINAGE FLOW OUT OF ONTARIO POSSIBLY MOVING IN...AND WILL RETURN VFR CONDITIONS AN HOUR OR TWO AFTER TAF ISSUANCE. TVC LOOKS TO BE IN THE CLEAR UNTIL LATE THIS AFTERNOON WHEN WINDS SHIFT TO THE NW AND BRINGS LAKE CLOUDS INLAND. HOWEVER...THINK CIGS WILL REMAIN VFR THROUGH THE TAF PERIOD FOR TVC. MPC && .PREV DISCUSSION... /ISSUED 532 AM EST SAT MAR 8 2008/ UPDATE...A QUICK UPDATE TO REFLECT DEVELOPMENT OF LIGHT SNOW AND FLURRIES OVER THE HIGHER TERRAIN. MOISTURE FLUXES DUE TO NE FLOW OFF LAKE HURON COMBINED WITH UPSLOPE FLOW OVER NORTH CENTRAL LOWER HAS HELPED AN AREA OF LIGHT SNOW AND FLURRIES TO GENERATE OVER THE PAST HOUR OR SO. WITH LITTLE CHANGE IN CONDITIONS EXPECTED TO OCCUR...HAVE UPDATED GRIDS TO INCLUDE A CHANCE OF LIGHT SNOW AND FLURRIES FARTHER WEST THROUGH THE MORNING. LITTLE TO NO ACCUMULATIONS ARE EXPECTED. NEW ZONES OUT SHORTLY. MPC && PREV DISCUSSION... /ISSUED 400 AM EST SAT MAR 8 2008/ DISCUSSION...03Z SURFACE/RUC ANALYSIS AND IR/WV/RADAR IMAGERY CONTINUE TO SHOW A AMPLIFIED PATTERN ACROSS NORTH AMERICA...WITH A WESTERN NOAM RIDGE AND A DEEP TROUGH RANGING FROM HUDSON BAY TO THE GREAT LAKES TO THE GULF COAST. CIRRUS SHIELD JUST AHEAD OF THE TROUGH AXIS WITHIN CONFLUENT MID-LEVEL FLOW CONTINUES TO SCRAPE BY THE SE CWA...WHILE SW-NE ORIENTATED SURFACE RIDGE AXIS IS SUPPLYING THE AREA WITH EXCEPTIONALLY DRY AIR (PWAT 0.06 IN) THAT HAS PREVENTED ANY PRECIP RELATED FROM THE POTENT STORM OVER THE MID-ATLANTIC REGION FROM REACHING THIS FAR NORTH. HOWEVER...THIS SURFACE HIGH IS ALSO PROVIDING THE AREA WITH AN ARCTIC AIRMASS (850MB TEMP -19C) AND INSTABILITY NEEDED TO GENERATE LAKE EFFECT SNOW (LES). THIS SNOW HAS BEEN MOSTLY CONFINED TO AREAS ALONG THE WEST ARM OF GRAND TRAVERSE BAY AND THE LEELANAU PENINSULA AND WHITEFISH POINT...BUT LITTLE IN THE WAY OF ACTIVITY ALONG THE LAKE HURON SHORELINE. WITH THE MODELS IN GOOD AGREEMENT THAT THE EAST COAST STORM WILL PASS WELL EAST OF THE AREA...LIGHT LAKE EFFECT PRECIP IS THE MAIN CONCERN OVER THE NEXT 24 HOURS. TODAY...POTENT MID-ATLANTIC STORM WILL STRENGTHEN FURTHER AS IT MOVES TOWARDS NEW ENGLAND BY THIS EVENING. AS THE PRESSURE GRADIENT TIGHTENS A BIT...LOW LEVEL WINDS WILL SHIFT FROM THE NORTH TO NE THROUGH MIDDAY...THEN BACK TO THE NORTH BY EARLY THIS EVENING. ALTHOUGH 850MB TEMPS MODERATE FROM THE UPPER NEG TEENS TO THE MID NEG TEENS...LOW-MID LEVEL WIND TRAJECTORIES ORIGINATE FROM A HUDSON BAY HIGH WHICH WILL MAINTAIN VERY DRY AIR (850-700MB RH 15-25 PCT) ACROSS NORTHERN MICHIGAN. THIS DRY AIR WILL KEEP A CAP ON LES POTENTIAL OFF LAKE HURON DESPITE THE REASONABLY LONG FETCHES. AS A RESULT...LOW CHANCY POPS ARE STILL WARRANTED FOR THE MORNING FROM ALPENA TO TAWAS BEFORE DIURNAL MIXING AND BACKING WINDS HELP TO DIMINISH LES ACTIVITY DURING THE AFTERNOON. LITTLE TO NO ACCUMULATIONS ARE EXPECTED. OTHERWISE...ACROSS THE REMAINDER OF NORTHERN MICHIGAN...LOOK FOR PLENTY OF SUNSHINE TO BE HAD...ESPECIALLY ACROSS DOWNSLOPING AREAS OF NW LOWER AND EASTERN UPPER. UPSLOPE FLOW ALONG WITH MOISTURE FLUX OFF HURON WILL HELP DIURNAL CU FORM OVER THE EASTERN FRINGES OF THE HIGHER TERRAIN...BUT THINK MIXING WILL ERODE THIS CLOUD COVER TOWARDS MID AND LATE AFTERNOON. HIGHS WILL RANGE FROM THE UPPER TEENS NORTH TO MID 20S SOUTH. TONIGHT...SURFACE HIGH PRESSURE WILL REMAIN THE DOMINANT FEATURE WHICH WOULD PLACE NORTHERN MICHIGAN BETWEEN THE DEEP LOW TO OUR EAST...AND A SHORTWAVE TROUGH TO OUR WEST. THIS LATTER FEATURE WILL SLIDE FROM THE UPPER GREAT PLAINS TO THE SOUTHERN MN/WISCONSIN BORDER AND WILL SPREAD UPPER LEVEL MOISTURE ACROSS THE AREA. HOWEVER...VERY DRY LOW/MID LEVEL AIR (850-700MB RH 10-20 PCT) WILL REMAIN ACROSS THE AREA WHILE ALL ISENTROPIC ASCENT WILL RESIDE TO OUR SW. THIS WILL KEEP ALL SYNOPTIC PRECIP AWAY FROM THE REGION...WHICH LEAVES LAKE EFFECT PROCESSES AS THE PRIMARY SNOW CHANCE. 850MB TEMPS WILL HOLD STEADY AROUND -15C AND CYCLONIC LOW LEVEL FLOW WILL REMAIN IN PLACE. GIVEN THE OVERWHELMING DRY AIR IN PLACE...HARD TO IMAGINE ANYTHING MORE THAN FLURRIES ALONG THE LAKE MICHIGAN SHORELINE AND NEAR APN AS WIND BECOME LOCKED IN THE NNW DIRECTION. ADDITIONALLY...GIVEN THE EXPECTED THINNESS OF THE CIRRUS...DO NOT BELIEVE THE CLOUD COVER WILL HAVE MUCH OF AN IMPACT ON LOW TEMPS OUTSIDE OF THE SW CWA. THEREFORE...THE TYPICAL COLD SPOTS ACROSS EASTERN UPPER AND NE LOWER STILL LOOK TO GO BELOW ZERO ONCE AGAIN. SUNDAY AND SUNDAY NIGHT...VERY LITTLE TO CHANGE OVER THESE PERIODS. SHORTWAVE TROUGH AND ASSOCIATED FORCING WILL PIVOT ACROSS THE SOUTHERN GREAT LAKES AND NORTHERN OHIO RIVER VALLEY...WHILE HIGH PRESSURE WILL CONTINUE ITS DOMINANCE OVER THE NORTHERN GREAT LAKES. 850MB TEMPS DO MODERATE A COUPLE DEGREES BY SUNDAY AFTERNOON WHILE VERY DRY AIR (850-700MB RH 10-20 PCT) WILL REMAIN PRESENT. WILL KEEP A CHANCE OF FLURRIES DURING THE MORNING AROUND THE GTV BAY REGION AND VICINITY BEFORE NNW WINDS SUBSIDE TO 10KTS OR LESS AS THE PRESSURE GRADIENT SLACKENS. OUTSIDE OF SOME HIGH CLOUDS...ANOTHER NICE DAY WITH TEMPS IN THE LOWER TO MID 20S. COULD BE ANOTHER GOOD RADIATIONAL COOLING NIGHT IF THE HIGH CLOUDS DISSIPATE. WILL LOWER TEMPS A FEW DEGREES SINCE BELIEVE THE HIGH CLOUDS WONT IMPACT THE COOLING CURVE THAT MUCH. MONDAY THROUGH WEDNESDAY...POSITIVE PNA PATTERN FINALLY BREAKS DOWN DURING THIS PERIODS AS A BARRAGE OF PACIFIC SHORTWAVES WITHIN FAST ZONAL FLOW BEAT DOWN THE WESTERN NOAM RIDGE. AS A RESULT...WARMER AIR OF PACIFIC ORIGIN WILL TRY TO WARM THE TEMPERATURES ACROSS THE GREAT LAKES CLOSER TO THE NORM. FIRST OF THE PACIFIC WAVES IS DUE TO PASS OVER THE NORTHERN GREAT LAKES ON TUESDAY. GFS BRINGS A MORE SOUTHERLY TRACK WITH THIS WAVE...WHICH WOULD PROVIDE NORTHERN MICHIGAN WITH PRECIP...WHILE THE ECMWF KEEPS THE FORCING NORTH OF THE AREA. WILL KEEP CONTINUITY FOR NOW. REGARDLESS...FORCING AND MOISTURE ARE LESS THAN IMPRESSIVE AND IT DOESNT LOOK TO BE A BIG DEAL. OUTSIDE OF THIS SYSTEM...MONDAY AND WEDNESDAY LOOK DRY. MPC && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. LH...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR LHZ348-349. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 532 AM EST SAT MAR 8 2008 .UPDATE...A QUICK UPDATE TO REFLECT DEVELOPMENT OF LIGHT SNOW AND FLURRIES OVER THE HIGHER TERRAIN. MOISTURE FLUXES DUE TO NE FLOW OFF LAKE HURON COMBINED WITH UPSLOPE FLOW OVER NORTH CENTRAL LOWER HAS HELPED AN AREA OF LIGHT SNOW AND FLURRIES TO GENERATE OVER THE PAST HOUR OR SO. WITH LITTLE CHANGE IN CONDITIONS EXPECTED TO OCCUR...HAVE UPDATED GRIDS TO INCLUDE A CHANCE OF LIGHT SNOW AND FLURRIES FARTHER WEST THROUGH THE MORNING. LITTLE TO NO ACCUMULATIONS ARE EXPECTED. NEW ZONES OUT SHORTLY. MPC && .PREV DISCUSSION... /ISSUED 400 AM EST SAT MAR 8 2008/ DISCUSSION...03Z SURFACE/RUC ANALYSIS AND IR/WV/RADAR IMAGERY CONTINUE TO SHOW A AMPLIFIED PATTERN ACROSS NORTH AMERICA...WITH A WESTERN NOAM RIDGE AND A DEEP TROUGH RANGING FROM HUDSON BAY TO THE GREAT LAKES TO THE GULF COAST. CIRRUS SHIELD JUST AHEAD OF THE TROUGH AXIS WITHIN CONFLUENT MID-LEVEL FLOW CONTINUES TO SCRAPE BY THE SE CWA...WHILE SW-NE ORIENTATED SURFACE RIDGE AXIS IS SUPPLYING THE AREA WITH EXCEPTIONALLY DRY AIR (PWAT 0.06 IN) THAT HAS PREVENTED ANY PRECIP RELATED FROM THE POTENT STORM OVER THE MID-ATLANTIC REGION FROM REACHING THIS FAR NORTH. HOWEVER...THIS SURFACE HIGH IS ALSO PROVIDING THE AREA WITH AN ARCTIC AIRMASS (850MB TEMP -19C) AND INSTABILITY NEEDED TO GENERATE LAKE EFFECT SNOW (LES). THIS SNOW HAS BEEN MOSTLY CONFINED TO AREAS ALONG THE WEST ARM OF GRAND TRAVERSE BAY AND THE LEELANAU PENINSULA AND WHITEFISH POINT...BUT LITTLE IN THE WAY OF ACTIVITY ALONG THE LAKE HURON SHORELINE. WITH THE MODELS IN GOOD AGREEMENT THAT THE EAST COAST STORM WILL PASS WELL EAST OF THE AREA...LIGHT LAKE EFFECT PRECIP IS THE MAIN CONCERN OVER THE NEXT 24 HOURS. TODAY...POTENT MID-ATLANTIC STORM WILL STRENGTHEN FURTHER AS IT MOVES TOWARDS NEW ENGLAND BY THIS EVENING. AS THE PRESSURE GRADIENT TIGHTENS A BIT...LOW LEVEL WINDS WILL SHIFT FROM THE NORTH TO NE THROUGH MIDDAY...THEN BACK TO THE NORTH BY EARLY THIS EVENING. ALTHOUGH 850MB TEMPS MODERATE FROM THE UPPER NEG TEENS TO THE MID NEG TEENS...LOW-MID LEVEL WIND TRAJECTORIES ORIGINATE FROM A HUDSON BAY HIGH WHICH WILL MAINTAIN VERY DRY AIR (850-700MB RH 15-25 PCT) ACROSS NORTHERN MICHIGAN. THIS DRY AIR WILL KEEP A CAP ON LES POTENTIAL OFF LAKE HURON DESPITE THE REASONABLY LONG FETCHES. AS A RESULT...LOW CHANCY POPS ARE STILL WARRANTED FOR THE MORNING FROM ALPENA TO TAWAS BEFORE DIURNAL MIXING AND BACKING WINDS HELP TO DIMINISH LES ACTIVITY DURING THE AFTERNOON. LITTLE TO NO ACCUMULATIONS ARE EXPECTED. OTHERWISE...ACROSS THE REMAINDER OF NORTHERN MICHIGAN...LOOK FOR PLENTY OF SUNSHINE TO BE HAD...ESPECIALLY ACROSS DOWNSLOPING AREAS OF NW LOWER AND EASTERN UPPER. UPSLOPE FLOW ALONG WITH MOISTURE FLUX OFF HURON WILL HELP DIURNAL CU FORM OVER THE EASTERN FRINGES OF THE HIGHER TERRAIN...BUT THINK MIXING WILL ERODE THIS CLOUD COVER TOWARDS MID AND LATE AFTERNOON. HIGHS WILL RANGE FROM THE UPPER TEENS NORTH TO MID 20S SOUTH. TONIGHT...SURFACE HIGH PRESSURE WILL REMAIN THE DOMINANT FEATURE WHICH WOULD PLACE NORTHERN MICHIGAN BETWEEN THE DEEP LOW TO OUR EAST...AND A SHORTWAVE TROUGH TO OUR WEST. THIS LATTER FEATURE WILL SLIDE FROM THE UPPER GREAT PLAINS TO THE SOUTHERN MN/WISCONSIN BORDER AND WILL SPREAD UPPER LEVEL MOISTURE ACROSS THE AREA. HOWEVER...VERY DRY LOW/MID LEVEL AIR (850-700MB RH 10-20 PCT) WILL REMAIN ACROSS THE AREA WHILE ALL ISENTROPIC ASCENT WILL RESIDE TO OUR SW. THIS WILL KEEP ALL SYNOPTIC PRECIP AWAY FROM THE REGION...WHICH LEAVES LAKE EFFECT PROCESSES AS THE PRIMARY SNOW CHANCE. 850MB TEMPS WILL HOLD STEADY AROUND -15C AND CYCLONIC LOW LEVEL FLOW WILL REMAIN IN PLACE. GIVEN THE OVERWHELMING DRY AIR IN PLACE...HARD TO IMAGINE ANYTHING MORE THAN FLURRIES ALONG THE LAKE MICHIGAN SHORELINE AND NEAR APN AS WIND BECOME LOCKED IN THE NNW DIRECTION. ADDITIONALLY...GIVEN THE EXPECTED THINNESS OF THE CIRRUS...DO NOT BELIEVE THE CLOUD COVER WILL HAVE MUCH OF AN IMPACT ON LOW TEMPS OUTSIDE OF THE SW CWA. THEREFORE...THE TYPICAL COLD SPOTS ACROSS EASTERN UPPER AND NE LOWER STILL LOOK TO GO BELOW ZERO ONCE AGAIN. SUNDAY AND SUNDAY NIGHT...VERY LITTLE TO CHANGE OVER THESE PERIODS. SHORTWAVE TROUGH AND ASSOCIATED FORCING WILL PIVOT ACROSS THE SOUTHERN GREAT LAKES AND NORTHERN OHIO RIVER VALLEY...WHILE HIGH PRESSURE WILL CONTINUE ITS DOMINANCE OVER THE NORTHERN GREAT LAKES. 850MB TEMPS DO MODERATE A COUPLE DEGREES BY SUNDAY AFTERNOON WHILE VERY DRY AIR (850-700MB RH 10-20 PCT) WILL REMAIN PRESENT. WILL KEEP A CHANCE OF FLURRIES DURING THE MORNING AROUND THE GTV BAY REGION AND VICINITY BEFORE NNW WINDS SUBSIDE TO 10KTS OR LESS AS THE PRESSURE GRADIENT SLACKENS. OUTSIDE OF SOME HIGH CLOUDS...ANOTHER NICE DAY WITH TEMPS IN THE LOWER TO MID 20S. COULD BE ANOTHER GOOD RADIATIONAL COOLING NIGHT IF THE HIGH CLOUDS DISSIPATE. WILL LOWER TEMPS A FEW DEGREES SINCE BELIEVE THE HIGH CLOUDS WONT IMPACT THE COOLING CURVE THAT MUCH. MONDAY THROUGH WEDNESDAY...POSITIVE PNA PATTERN FINALLY BREAKS DOWN DURING THIS PERIODS AS A BARRAGE OF PACIFIC SHORTWAVES WITHIN FAST ZONAL FLOW BEAT DOWN THE WESTERN NOAM RIDGE. AS A RESULT...WARMER AIR OF PACIFIC ORIGIN WILL TRY TO WARM THE TEMPERATURES ACROSS THE GREAT LAKES CLOSER TO THE NORM. FIRST OF THE PACIFIC WAVES IS DUE TO PASS OVER THE NORTHERN GREAT LAKES ON TUESDAY. GFS BRINGS A MORE SOUTHERLY TRACK WITH THIS WAVE...WHICH WOULD PROVIDE NORTHERN MICHIGAN WITH PRECIP...WHILE THE ECMWF KEEPS THE FORCING NORTH OF THE AREA. WILL KEEP CONTINUITY FOR NOW. REGARDLESS...FORCING AND MOISTURE ARE LESS THAN IMPRESSIVE AND IT DOESNT LOOK TO BE A BIG DEAL. OUTSIDE OF THIS SYSTEM...MONDAY AND WEDNESDAY LOOK DRY. MPC PREV DISCUSSION... /ISSUED 1152 PM EST FRI MAR 7 2008/ AVIATION...LOW LEVEL WINDS HAVE REMAINED BRISK ENOUGH TO WARD OFF LAND BREEZE FORMATION ACROSS TVC...AND LIGHT LAKE EFFECT SNOW SHOWERS HAVE FLIRTED WITH THE AIRPORT. STILL FEEL THAT THESE SNOW SHOWERS WILL REMAIN TO THE WEST THROUGH THE NIGHT. PLN IS CLEAR...AND SEE NO REAL CHANGE IN THOSE CONDITIONS INTO TOMORROW. AT APN...LAKE EFFECT STRATO CU SHOULD CONTINUE TO DEVELOP ACROSS MUCH OF NE LOWER...AS LOW LEVEL WINDS VEER AROUND TO NE AND INCREASE THE FETCH LENGTH. WILL JUST BACK OFF A BIT ON THE TIMING IF THIS...AND THE ASSOCIATED VCSH THAT WILL LIKELY DEVELOP IN THE AREA. WILL BE FIGHTING STRATO CU AND LIGHT LAKE EFFECT INTO TOMORROW AS WELL. SMD && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. LH...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR LHZ348-349. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 420 AM EST SAT MAR 8 2008 .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS INDICATED AN AMPLIFIED PATTERN WITH A MID LEVEL TROUGH AXIS FROM E OF HUDSON BAY THROUGH THE WRN GREAT LAKES INTO THE LOWER MISSISSIPPI VALLEY. AN UPSTREAM SHORTWAVE IN NW FLOW WAS DESCENDING SOUTH THROUGH MANITOBA INTO NORTH DAKOTA EARLY THIS MORNING. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY INTO WRN LAKE SUPERIOR AND WRN WI. WEAK NRLY LOW LEVEL FLOW AHEAD OF THE RIDGE AXIS COMBINED WITH 850 MB TEMPS AROUND -21C CONTINUED TO SUPPORT WEAK MULTIPLE WIND PARALLEL LES BANDS INTO ALGER-LUCE AND NRN SCHOOLCRAFT COUNTIES. VERY DRY AIR AND EXTENSIVE ICE COVER HAS LIMITED LES INTO NW UPPER MI WITH ONLY WEAK BANDS OVER THE KEWEENAW PENINSULA NORTH OF HOUGHTON PER IR SATELLITE LOOP. IDEAL RADIATIONAL COOLING CONDITIONS HAS ALLOWED TEMPS TO NOSEDIVE THIS MORNING. -24F TEMPS WERE REPORTED AT BOTH THE WAKEFIELD AND STONINGTON RAWS SITES WITHIN THE PAST HR WITH -19F AT THE NWS MQT. .DISCUSSION... MAIN FCST CONCERNS ARE LES TRENDS AND MIN TEMPS. WIDELY-SPACED AND WEAK LES BANDS OVER THE ERN AND NCNTRL COUNTIES OF THE FCST AREA WILL CONTINUE TO BE NEGATIVELY IMPACTED INTO SUNDAY BY ANTICYCLONIC N-NE FLOW AND VERY DRY AIR UPSTREAM. WILL KEEP CHC POPS IN FOR NCNTRL COUNTIES INTO SUNDAY BUT EXPECT ACCUMULATIONS TO BE LESS THAN INCH FOR ANY 12 HR PERIOD. DIURNAL HEATING AND VERY LIGHT WIND FIELD WILL ALSO FURTHER DISRUPT WEAK LES BANDS DURING THE DAYTIME. EVENTUALLY...TEMPS WARMING TO -13/-14C AT TOP OF THE INVERSION AND LIGHT WIND FIELD SHOULD ALLOW LES TO END BY SUN EVENING. CONTINUED RIDGING WILL KEEP THE FCST AREA DRY INTO MONDAY. TEMPS SLOWLY MODERATE OVER THE WEEKEND AS DAYTIME HIGHS REACH INTO THE UPPER TEENS TO AROUND 20F ON SATURDAY AND LOW TO MID 20S ON SUNDAY. WAA IN WRLY FLOW AHEAD OF NEXT CLIPPER SYSTEM WILL BRING HIGHS ON MONDAY INTO THE LOW 30S. DESPITE THE SLOWLY MODERATING AIRMASS...IDEAL RADIATIONAL COOLING WITH LIGHT WINDS...CLEAR SKIES AND LOW PCPN WATER VALUES AROUND .1 INCH OR LESS WILL ALLOW INLAND READINGS TO FALL INTO THE SINGLE DIGITS BLO ZERO SAT NIGHT AND SUN NIGHT. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... VFR CONDITIONS WILL CONTINUE AT KCMX THROUGH SAT EVENING. KSAW WILL HAVE VFR FOR MOST OF THE TIME...EXCEPT AS THE WIND GOES NE LATE SAT MORNING THROUGH SAT AFTERNOON...MVFR CONDITIONS ARE POSSIBLE WITH LAKE EFFECT SNOW SHOWERS WITH A FAVORABLE WIND FOR LAKE EFFECT SNOW GETTING THAT FAR INLAND. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... FREEZING SPRAY WILL REMAIN THE MAIN CONCERN AS A COLD AIRMASS REMAINS. A HIGH PRESSURE RIDGE AVERAGING 30.4 INCHES WILL DOMINATE THE GREAT LAKES AREA THROUGH THE WEEKEND....WITH LIGHT WINDS LESS THAN 20KTS EXPECTED. THIS HIGH SHOULD SHIFT TO OUR SOUTH ON MONDAY...MAKING WAY FOR A 29.8 INCH LOW OVER CENTRAL MANITOBA MONDAY NIGHT TO CROSS LAKE SUPERIOR TUESDAY. INCREASED WINDS MONDAY...BUT STILL BELOW 30KTS. HIGH PRESSURE OF 30.0 INCHES WILL BRIEFLY TAKE OVER TUESDAY NIGHT AND WEDNESDAY...AS A 29.5 INCH LOW DEVELOPS OVER MANITOBA. && UPPER MICHIGAN...NONE. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING FROM 7 PM EST THIS EVENING TO 8 AM EDT SUNDAY FOR LSZ267. LAKE MICHIGAN...NONE. && $$ SYNOPSIS...VOSS DISCUSSION...VOSS AVIATION...GJM MARINE...KF mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 400 AM EST SAT MAR 8 2008 .DISCUSSION...03Z SURFACE/RUC ANALYSIS AND IR/WV/RADAR IMAGERY CONTINUE TO SHOW A AMPLIFIED PATTERN ACROSS NORTH AMERICA...WITH A WESTERN NOAM RIDGE AND A DEEP TROUGH RANGING FROM HUDSON BAY TO THE GREAT LAKES TO THE GULF COAST. CIRRUS SHIELD JUST AHEAD OF THE TROUGH AXIS WITHIN CONFLUENT MID-LEVEL FLOW CONTINUES TO SCRAPE BY THE SE CWA...WHILE SW-NE ORIENTATED SURFACE RIDGE AXIS IS SUPPLYING THE AREA WITH EXCEPTIONALLY DRY AIR (PWAT 0.06 IN) THAT HAS PREVENTED ANY PRECIP RELATED FROM THE POTENT STORM OVER THE MID-ATLANTIC REGION FROM REACHING THIS FAR NORTH. HOWEVER...THIS SURFACE HIGH IS ALSO PROVIDING THE AREA WITH AN ARCTIC AIRMASS (850MB TEMP -19C) AND INSTABILITY NEEDED TO GENERATE LAKE EFFECT SNOW (LES). THIS SNOW HAS BEEN MOSTLY CONFINED TO AREAS ALONG THE WEST ARM OF GRAND TRAVERSE BAY AND THE LEELANAU PENINSULA AND WHITEFISH POINT...BUT LITTLE IN THE WAY OF ACTIVITY ALONG THE LAKE HURON SHORELINE. WITH THE MODELS IN GOOD AGREEMENT THAT THE EAST COAST STORM WILL PASS WELL EAST OF THE AREA...LIGHT LAKE EFFECT PRECIP IS THE MAIN CONCERN OVER THE NEXT 24 HOURS. TODAY...POTENT MID-ATLANTIC STORM WILL STRENGTHEN FURTHER AS IT MOVES TOWARDS NEW ENGLAND BY THIS EVENING. AS THE PRESSURE GRADIENT TIGHTENS A BIT...LOW LEVEL WINDS WILL SHIFT FROM THE NORTH TO NE THROUGH MIDDAY...THEN BACK TO THE NORTH BY EARLY THIS EVENING. ALTHOUGH 850MB TEMPS MODERATE FROM THE UPPER NEG TEENS TO THE MID NEG TEENS...LOW-MID LEVEL WIND TRAJECTORIES ORIGINATE FROM A HUDSON BAY HIGH WHICH WILL MAINTAIN VERY DRY AIR (850-700MB RH 15-25 PCT) ACROSS NORTHERN MICHIGAN. THIS DRY AIR WILL KEEP A CAP ON LES POTENTIAL OFF LAKE HURON DESPITE THE REASONABLY LONG FETCHES. AS A RESULT...LOW CHANCY POPS ARE STILL WARRANTED FOR THE MORNING FROM ALPENA TO TAWAS BEFORE DIURNAL MIXING AND BACKING WINDS HELP TO DIMINISH LES ACTIVITY DURING THE AFTERNOON. LITTLE TO NO ACCUMULATIONS ARE EXPECTED. OTHERWISE...ACROSS THE REMAINDER OF NORTHERN MICHIGAN...LOOK FOR PLENTY OF SUNSHINE TO BE HAD...ESPECIALLY ACROSS DOWNSLOPING AREAS OF NW LOWER AND EASTERN UPPER. UPSLOPE FLOW ALONG WITH MOISTURE FLUX OFF HURON WILL HELP DIURNAL CU FORM OVER THE EASTERN FRINGES OF THE HIGHER TERRAIN...BUT THINK MIXING WILL ERODE THIS CLOUD COVER TOWARDS MID AND LATE AFTERNOON. HIGHS WILL RANGE FROM THE UPPER TEENS NORTH TO MID 20S SOUTH. TONIGHT...SURFACE HIGH PRESSURE WILL REMAIN THE DOMINANT FEATURE WHICH WOULD PLACE NORTHERN MICHIGAN BETWEEN THE DEEP LOW TO OUR EAST...AND A SHORTWAVE TROUGH TO OUR WEST. THIS LATTER FEATURE WILL SLIDE FROM THE UPPER GREAT PLAINS TO THE SOUTHERN MN/WISCONSIN BORDER AND WILL SPREAD UPPER LEVEL MOISTURE ACROSS THE AREA. HOWEVER...VERY DRY LOW/MID LEVEL AIR (850-700MB RH 10-20 PCT) WILL REMAIN ACROSS THE AREA WHILE ALL ISENTROPIC ASCENT WILL RESIDE TO OUR SW. THIS WILL KEEP ALL SYNOPTIC PRECIP AWAY FROM THE REGION...WHICH LEAVES LAKE EFFECT PROCESSES AS THE PRIMARY SNOW CHANCE. 850MB TEMPS WILL HOLD STEADY AROUND -15C AND CYCLONIC LOW LEVEL FLOW WILL REMAIN IN PLACE. GIVEN THE OVERWHELMING DRY AIR IN PLACE...HARD TO IMAGINE ANYTHING MORE THAN FLURRIES ALONG THE LAKE MICHIGAN SHORELINE AND NEAR APN AS WIND BECOME LOCKED IN THE NNW DIRECTION. ADDITIONALLY...GIVEN THE EXPECTED THINNESS OF THE CIRRUS...DO NOT BELIEVE THE CLOUD COVER WILL HAVE MUCH OF AN IMPACT ON LOW TEMPS OUTSIDE OF THE SW CWA. THEREFORE...THE TYPICAL COLD SPOTS ACROSS EASTERN UPPER AND NE LOWER STILL LOOK TO GO BELOW ZERO ONCE AGAIN. SUNDAY AND SUNDAY NIGHT...VERY LITTLE TO CHANGE OVER THESE PERIODS. SHORTWAVE TROUGH AND ASSOCIATED FORCING WILL PIVOT ACROSS THE SOUTHERN GREAT LAKES AND NORTHERN OHIO RIVER VALLEY...WHILE HIGH PRESSURE WILL CONTINUE ITS DOMINANCE OVER THE NORTHERN GREAT LAKES. 850MB TEMPS DO MODERATE A COUPLE DEGREES BY SUNDAY AFTERNOON WHILE VERY DRY AIR (850-700MB RH 10-20 PCT) WILL REMAIN PRESENT. WILL KEEP A CHANCE OF FLURRIES DURING THE MORNING AROUND THE GTV BAY REGION AND VICINITY BEFORE NNW WINDS SUBSIDE TO 10KTS OR LESS AS THE PRESSURE GRADIENT SLACKENS. OUTSIDE OF SOME HIGH CLOUDS...ANOTHER NICE DAY WITH TEMPS IN THE LOWER TO MID 20S. COULD BE ANOTHER GOOD RADIATIONAL COOLING NIGHT IF THE HIGH CLOUDS DISSIPATE. WILL LOWER TEMPS A FEW DEGREES SINCE BELIEVE THE HIGH CLOUDS WONT IMPACT THE COOLING CURVE THAT MUCH. MONDAY THROUGH WEDNESDAY...POSITIVE PNA PATTERN FINALLY BREAKS DOWN DURING THIS PERIODS AS A BARRAGE OF PACIFIC SHORTWAVES WITHIN FAST ZONAL FLOW BEAT DOWN THE WESTERN NOAM RIDGE. AS A RESULT...WARMER AIR OF PACIFIC ORIGIN WILL TRY TO WARM THE TEMPERATURES ACROSS THE GREAT LAKES CLOSER TO THE NORM. FIRST OF THE PACIFIC WAVES IS DUE TO PASS OVER THE NORTHERN GREAT LAKES ON TUESDAY. GFS BRINGS A MORE SOUTHERLY TRACK WITH THIS WAVE...WHICH WOULD PROVIDE NORTHERN MICHIGAN WITH PRECIP...WHILE THE ECMWF KEEPS THE FORCING NORTH OF THE AREA. WILL KEEP CONTINUITY FOR NOW. REGARDLESS...FORCING AND MOISTURE ARE LESS THAN IMPRESSIVE AND IT DOESNT LOOK TO BE A BIG DEAL. OUTSIDE OF THIS SYSTEM...MONDAY AND WEDNESDAY LOOK DRY. MPC && .PREV DISCUSSION... /ISSUED 1152 PM EST FRI MAR 7 2008/ AVIATION...LOW LEVEL WINDS HAVE REMAINED BRISK ENOUGH TO WARD OFF LAND BREEZE FORMATION ACROSS TVC...AND LIGHT LAKE EFFECT SNOW SHOWERS HAVE FLIRTED WITH THE AIRPORT. STILL FEEL THAT THESE SNOW SHOWERS WILL REMAIN TO THE WEST THROUGH THE NIGHT. PLN IS CLEAR...AND SEE NO REAL CHANGE IN THOSE CONDITIONS INTO TOMORROW. AT APN...LAKE EFFECT STRATO CU SHOULD CONTINUE TO DEVELOP ACROSS MUCH OF NE LOWER...AS LOW LEVEL WINDS VEER AROUND TO NE AND INCREASE THE FETCH LENGTH. WILL JUST BACK OFF A BIT ON THE TIMING IF THIS...AND THE ASSOCIATED VCSH THAT WILL LIKELY DEVELOP IN THE AREA. WILL BE FIGHTING STRATO CU AND LIGHT LAKE EFFECT INTO TOMORROW AS WELL. SMD && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. LH...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR LHZ348-349. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 337 PM CST SAT MAR 8 2008 .DISCUSSION... MAIN ISENTROPIC LIFT WITH THIS SYSTEM LOOKS TO BE OVER SOUTH CENTRAL MINNESOTA THIS EVENING...WITH WEAKENING LIFT OVER THE REST OF THE AREA OVERNIGHT AS THE MID LEVEL LOW SPINS SSE. SREF UVV AND POPS INDICATE THIS GENERAL TREND OVERNIGHT INTO MIDDAY SUNDAY. CLOUDS WILL LINGER OVER MOST OF THE AREA ON SUNDAY WITH THE CYCLONIC FLOW. WONDER IF MOS GUIDANCE LOOKS A LITTLE COOL IN A FEW AREAS TONIGHT. WITH NOT MUCH CLEARING...GFS LAMP NUMBERS MAY LOOK A LITTLE BETTER. LOOKS LIKE WE WILL BE WARMING MONDAY INTO WEDNESDAY AHEAD OF THE PACIFIC SYSTEM FOR WEDNESDAY NIGHT AND THURSDAY. NAEFS CHARTS SHOWING HIGHEST PROBS FOR RAIN INITIALLY WITH THIS SYSTEM WHICH MAKES SENSE...WITH THE WARM 850 MB TEMPS THAT ARE FORECAST. WILL INDICATE CHANGE TO SNOW WITH THE COLD FRONT AND POSSIBLE VORT PASSING JUST SOUTH OF THE AREA WEDNESDAY NIGHT OR EARLY THURSDAY. TEMPS COOLING TO NEAR OR A LITTLE BELOW NORMAL BEHIND THE SYSTEM FOR A DAY OR TWO. MODELS STILL SHOWING THE POTENTIAL FOR A SIG SYSTEM DEVELOPING IN THE PLAINS MONDAY AND TUESDAY. && .AVIATION.../18Z TAF ISSUANCE/ AFOREMENTIONED STRONG CIRCULATION ALOFT NOW INTO NW MN. SFC LOW REMAINS A LITTLE BIT STRONGER THAN MODELS HAD BEEN INDICATING. INITIAL AREA OF SNOW HAS BEEN DROPPING SSE THROUGH WESTERN MN. 12Z NAM AND GFS CONTINUE THE TREND OF SLOWING DOWN THE EASTWARD PROGRESSION OF THE SNOW...AND 15Z RUC IS EVEN LATER. THUS HAVE CONTINUED THE FORECAST OF SNOW THIS AFTERNOON/EVENING AT AXN AND RWF... BUT DELAYED IT ELSEWHERE. IN FACT...IT SEEMS AS IF STC AND MSP MAY NOT SEE MUCH SNOW OUT OF THIS INITIAL WAVE. MEANWHILE NAM AND GFS HINT AT DEVELOPMENT OF DEFORMATION ZONE THIS EVENING AND THROUGH THE NIGHT FROM NW/NC MN ACROSS THE MSP REGION... TO THE ESE OF MSP...PROBABLY AFFECTING STC AND MSP. BAND MAY THEN PIVOT AROUND THE MSP METRO OR SE MN INTO SUNDAY MORNING...WITH SNOW POSSIBLE AT RNH AND EAU. HAVE THEREFORE PLACED LOWEST VSBY FOR MSP STARTING AROUND 06Z FOR SEVERAL HOURS. SAID DEFORMATION MAY BE RATHER NARROW SO WILL INDICATE SNOW FOR ONLY A FEW HOURS SINCE IT WILL LIKELY SHIFT A LITTLE. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ 99/JPR/TDK mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1207 PM CST SAT MAR 8 2008 .DISCUSSION... A RIDGE OF HIGH PRESSURE COVERED THE EASTERN CWA EARLY THIS MORNING WITH DOUBLE DIGIT BELOW ZERO TEMPERATURES FROM LAKEVILLE TO LADYSMITH AND EAU CLAIRE. A STRONG CIRCULATION ALOFT IS MOVING INTO ND AND NW MN ATTM. ASSOCIATED SURFACE LOW OVER ND IS ABOUT 2 MILLIBARS DEEPER OVER THE NAM FORECAST. THE NAM IS ALSO NOT DEEP ENOUGH NOR FAR ENOUGH WEST WITH THE LOW IN SOUTHWEST VA EARLY THIS MORNING. THE CIRCULATION TO OUR NW WILL DROP SLOWLY SOUTHEAST TODAY AND TONIGHT WITH A CLOSED LOW ALOFT JUST ABOUT OVER THE TWIN CITIES SUNDAY MORNING. PARAMETERS LOOK VERY GOOD FOR LIGHT SNOW AND WILL KEEP LIKELY POPS IN PLAY DESPITE MINIMAL POPS FROM MOS. NAM BEST LAYER MOISTURE AND Q-VECTOR CONVERGENCE SPREADS ACROSS THE EASTERN TWO-THIRDS OF THE CWA BETWEEN 18Z AND 06Z. THIS ALSO LINES UP WELL WITH THE SATURATION AND ADIABATIC OMEGA SEEN ON THE 280K THETA SURFACE. MIXING RATIOS DURING THIS TIME FRAME AVERAGE AROUND 1.5 G/KG. NET VERTICAL DISPLACEMENT TODAY A RESPECTABLE 20 MILLIBARS. OVERALL...EXPECT FROM A HALF INCH TO 1.5 INCHES OF SNOW THROUGH TONIGHT WITH THE 1.5 INCHES BEING ACROSS CENTRAL MN IN THE LITTLE FALLS...ST CLOUD AND MORA AREAS. LINGERING FLURRIES ON SUNDAY AS THE UPPER LOW MOVES SLOWLY SOUTHEAST. A WESTERLY FLOW ALOFT THEN DEVELOPS EARLY NEXT WEEK ALONG WITH A WARMING TREND. A SMALL THREAT FOR SOME RAIN STILL LOOKS GOOD BEGINNING WEDNESDAY FROM CENTRAL MN ON NORTHWARD AND ACROSS WEST CENTRAL WI. BETTER CHANCES FOR RAIN OR RAIN CHANGING TO SNOW WEDNESDAY NIGHT AND EARLY THURSDAY AS A SHORT WAVE AND SURFACE COLD FRONT MOVE ACROSS THE REGION. && .AVIATION.../18Z TAF ISSUANCE/ AFOREMENTIONED STRONG CIRCULATION ALOFT NOW INTO NW MN. SFC LOW REMAINS A LITTLE BIT STRONGER THAN MODELS HAD BEEN INDICATING. INITIAL AREA OF SNOW HAS BEEN DROPPING SSE THROUGH WESTERN MN. 12Z NAM AND GFS CONTINUE THE TREND OF SLOWING DOWN THE EASTWARD PROGRESSION OF THE SNOW...AND 15Z RUC IS EVEN LATER. THUS HAVE CONTINUED THE FORECAST OF SNOW THIS AFTERNOON/EVENING AT AXN AND RWF... BUT DELAYED IT ELSEWHERE. IN FACT...IT SEEMS AS IF STC AND MSP MAY NOT SEE MUCH SNOW OUT OF THIS INITIAL WAVE. MEANWHILE NAM AND GFS HINT AT DEVELOPMENT OF DEFORMATION ZONE THIS EVENING AND THROUGH THE NIGHT FROM NW/NC MN ACROSS THE MSP REGION... TO THE ESE OF MSP...PROBABLY AFFECTING STC AND MSP. BAND MAY THEN PIVOT AROUND THE MSP METRO OR SE MN INTO SUNDAY MORNING...WITH SNOW POSSIBLE AT RNH AND EAU. HAVE THEREFORE PLACED LOWEST VSBY FOR MSP STARTING AROUND 06Z FOR SEVERAL HOURS. SAID DEFORMATION MAY BE RATHER NARROW SO WILL INDICATE SNOW FOR ONLY A FEW HOURS SINCE IT WILL LIKELY SHIFT A LITTLE. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ RAH/TDK mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 239 PM CST SAT MAR 8 2008 .SHORT TERM...TONIGHT THROUGH TUESDAY. PRIMARY CONCERN FOR THE SHORT TERM WILL BE TEMPS...THEN POTENTIAL FOR FLURRIES AND CLDS. A SURFACE TROF OF LOW PRES EAST OF WAYNE AND NEAR COLUMBUS HIGHLIGHTED THE WIND SHIFT FM SW TO NORTHWEST AND MORE SUBSTANTIAL CLD COVER TO THE N. IN THE WARM SECTOR...TEMPERATURES WERE WARMING INTO THE 40S AND 50S AROUND ALBION TO ODX TO EAR AND MUCH OF SOUTH CNTRL NEBRASKA. THE SNOW WAS CLOSER TO THE NRN SFC LOW AROUND FARGO AND WATERTOWN IN ERN SD...THEN SE INTO MN AND IA. VISIBLE STLT IMAGERY HAD AN EXTENSIVE AREA OF LOW AND MID CLDS WITH THIS WEATHER SYSTEM. AT 20Z...THE RUC HAD A LARGE CLOSED H5 LOW FM LAKE WINNIPEG INTO NRN MN...AND THIS WAS NOTED ON WATER VAPOR STLT IMAGERY AS WELL. A SERIES OF SHORTWAVES WERE DROPPING S AROUND THE LOW. THE AREA OF LOW PRES OVR THE EASTERN DAKOTAS WILL MOVE INTO IA BY MORNING...DRAGGING THE COLD FRONT THRU AND COLD AIR INTO THE REGION. THE STRATOCU SHOULD CONTINUE TO EXPAND INTO THE FCST AREA TONIGHT AND SUNDAY. THE MORE ORGANIZED LIGHT SNOW SHOULD BE CLOSER TO THE SFC LOW TO THE EAST OF THE FCST AREA. AS COLDER AIR AND SUFFICIENT RH IN THE DENDRITIC LAYER MOVE IN AND SOME WEAK UVV LATER TONIGHT...IT SHOULD BE EASIER TO GET FLURRIES AND POSSIBLY LIGHT SNOW. BY SUNDAY EVENING...WE ARE STILL UNDER THE INFLUENCE OF CYCLONIC FLOW AND THE COLD TEMPS. HAVE HIGHS SUNDAY 10 TO 20 DEGREES BELOW NORMAL...AROUND FREEZING FOR PARTS OF WESTERN IOWA TO THE LOWER 40S AROUND ALBION AND WEST OF BIE. LINGERED SOME FLURRIES INTO THE EVENING...ALTHOUGH COLDER TEMPS WILL BE WELL TO OUR EAST. SFC HIGH PRES AND LIGHT WINDS SHOULD ALLOW TEMPS TO DROP BACK INTO THE TEENS MONDAY MORNING...WITH COLDER TEMPS FOR THOSE WITH DEEPER SNOWPACK. THE SURFACE HIGH IS A LITTLE SLOW TO MOVE OUT OF THE REGION...SO HAVE COOLER HIGHS IN THE LOWER 40S EAST...WITH LOWER 50S WEST. STILL ON TRACK TO BE MUCH WARMER TUESDAY WITH HIGHS IN THE 50S AND 60S. .LONG TERM...TUESDAY NIGHT THROUGH SATURDAY. CAN NOT SEEM TO SHAKE THE HOLD OF OVERALL LA NINA PATTERN OF THIS WINTER...AND THE FORECAST FOR LATER IN THE WEEK BEARS THIS OUT. AFTER SHORT WAVE RIDGING BRINGS WARM WEATHER TO THE REGION ON TUESDAY AND THE FIRST PART OF WEDNESDAY...UPPER TROUGH WILL SWEEP THROUGH THE REGION...REINFORCING MEAN LONG WAVE TROUGH POSITION OVER THE EASTERN HALF OF THE COUNTRY. THIS LEAVES OUR PART OF THE COUNTRY IN NORTHWEST FLOW ALOFT WITH...WITH MUCH OF THE CWA ON THE COLD SIDE OF LOW LEVEL BAROCLINIC ZONE. SO BOTTOM LINE IS THAT TEMPERATURES WERE TRIMMED EACH DAY WITH THURSDAY THROUGH SATURDAY REMAINING BELOW 50 DEGREES. PRECIPITATION CHANCES WILL BE TOUGH TO DETERMINE AFTER MAIN COLD FRONT SWEEPS THROUGH ON WEDNESDAY. HAVE KEPT A CHANCE FOR RAIN OR A RAIN/SNOW MIX WITH THAT COLD FRONT WEDNESDAY NIGHT AND EARLY THURSDAY. MODELS ARE SIMILAR IN KEEPING MOST OF THURSDAY AND FRIDAY DRY. THEN LATE FRIDAY AFTERNOON THROUGH SATURDAY...PRECIPITATION FORECAST CONFIDENCE WANES. HOWEVER...BOTH 12Z GFS AND 00Z ECMWF BRING SURFACE LOW PRESSURE THROUGH THE PLAINS SOUTH OF NEBRASKA. EAST OR NORTHEAST LOW LEVEL FLOW WILL BRING RELATIVELY COOL SURFACE AIR INTO THE REGION AS PACIFIC MOISTURE OVERRIDES IT FROM THE WEST AND NORTHWEST. BOTH MODELS GENERATE PRECIPITATION...BUT ECMWF IS FASTER IN MOVING IT IN AND OUT...AND IS QUITE A BIT COLDER. HAVE FOLLOWED GFS FOR THE MOST PART AS ITS ENSEMBLE MEMBERS WERE RELATIVELY CONSISTENT ON TIMING OF PRECIPITATION BEGINNING LATE FRIDAY...AND ENDING IT SATURDAY. ALSO...TEMPERATURE PROFILES WERE A BIT WARMER AND SEEMED MORE REASONABLE GIVEN ASSUMED UPPER AIR FLOW. HAVE INTRODUCED A CHANCE FOR RAIN OR SNOW TO THE FRIDAY NIGHT AND SATURDAY PERIODS...WITH ALL SNOW IN THE NORTH. IF ECMWF VERIFIES...MOST OF THE PRECIPITATION SHOULD BE ALL SNOW AND WILL LIKELY BE EAST OF THE AREA ON SATURDAY. && .AVIATION... FOR TAF SITES KOMA/KLNK/KOFK. SOUTHWARD MOVEMENT OF MVFR CIGS OVER THE DAKOTAS IN ASSOCIATION WITH FROPA WILL AFFECT ALL TAF SITES THRU 09/18Z. MODELS SUGGEST POSSIBLE OCCASIONAL IFR CONDITIONS...MAINLY AT OFK BTW 12Z-18Z TIMEFRAME. HAVE OPTED THOUGH TO LEAVE OUT OF TAFS FOR NOW DUE TO LOW CONFIDENCE OF IT OCCURRING. OTHERWISE...LIGHT NW WINDS EXPECTED ALL SITES. MOISTURE NOT DEEP AND DO NOT ANTICIPATE ANY PCPN DVLPG. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ ZAPOTOCNY/DERGAN/DEE ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 113 PM EDT SUN MAR 9 2008 .SYNOPSIS... THE LOW PRESSURE SYSTEM THAT BROUGHT THE WINTRY PRECIPITATION TO THE REGION WILL MOVE AWAY TO THE NORTHEAST TODAY. GUSTY SOUTHWEST TO WEST WINDS WILL BE QUITE STRONG THROUGH MIDDAY...ESPECIALLY IN THE CENTRAL ADIRONDACKS AND CENTRAL AND SOUTHERN VERMONT. LINGERING SNOW SHOWERS IN THE MOUNTAINS WILL TAPER OFF TONIGHT. TEMPERATURES WILL BE BELOW NORMAL THROUGH MIDWEEK...THEN A WARMING TREND WILL MOVE TEMPERATURES ABOVE NORMAL AT THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 929 AM EDT SUNDAY...THE NORTH COUNTRY REMAINS IN DEEP-LAYER CYCLONIC FLOW ON UPSTREAM SIDE OF DEPARTING LOW OVER NRN ME AT 1315Z. LATEST RUC ANALYSIS INDICATES BAND OF 45-55KT 850MB WINDS ACROSS OUR SRN ZONES...AND THIS SHOULD HELP CONTRIBUTE TO SOME WLY SFC WIND GUSTS OF 35-40 MPH IN THE ADVISORY AREA THROUGH LATE THIS MORNING. OVERALL GRADIENT WEAKENS THIS AFTERNOON...SO CURRENT PLAN IS TO DROP THE WIND ADVISORY ON TIME AT 15Z. BY 21Z...850MB FLOW BECOMES NWLY AND DECREASES TO 30-35 KTS. OTHERWISE...EXPECT A FEW SUNNY BREAKS TO DEVELOP...ESPECIALLY THIS AFTN. DOWNSLOPE FLOW COMPONENT SHOULD ALSO FAVOR DIMINISHING CLOUDS EAST OF THE ADIRONDACKS IN THE CHAMPLAIN VALLEY AND EAST OF THE GREEN MTNS TOWARD/WITHIN THE CONNECTICUT RIVER VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... AS OF 0412 AM EDT SUNDAY...RIDGE OF HIGH PRESSURE POKING NORTHEAST OUT OF OHIO VALLEY INTO THE NORTHEAST WILL BRING FAIR WEATHER FOR THE FIRST PART OF THE WEEK. HOWEVER LOW HEIGHTS IN THE EASTERN US WILL KEEP TEMPS BELOW NORMAL. LOW RH AIR OVER THE REGION...SO SOME SUN EXPECTED. HOWEVER WITH TROFINESS OVER EASTERN US AND VICINITY OF JET...DON`T THINK IT WILL BE QUITE AS CLOUD FREE AS MOS WOULD LIKE. WENT A DEGREE OR TWO WARMER THAN GUIDANCE MONDAY AND TUESDAY COUNTING ON SOME MORE SUNSHINE TO WARM US UP. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 0412 AM EDT SUNDAY...CLIPPER TYPE SYSTEM TO DIVE DOWN IN NORTHWEST FLOW LATE TUESDAY INTO WEDNESDAY. TEMPS COLD ENOUGH FOR SNOW...BUT WITH LESS MOISTURE TO WORK WITH ONLY CHC POPS. SHORTWAVE RIDGING FOLLOWS...THEN A WARM FRONT THURSDAY FOLLOWED BY COLD FRONT ON FRIDAY. CHC POPS...WITH SOME RAIN MIXED IN ON THURSDAY WITH WARMER TEMPS. && .AVIATION /18Z SUNDAY THROUGH THURSDAY/... THROUGH 18Z MONDAY...MAINLY VFR/MVFR COND EXPECTED AT ALL FORECAST SITES THRU 00Z MON. KSLK MAY SEE SOME IFR -SW FROM 18Z-21Z THAT MAY REDUCE VSBY TO LESS THAN 3SM AT TIMES. OTHERWISE...CEILINGS THRU 00Z MON WILL VARY FROM VFR TO MVFR. AFT 00Z MON...MAINLY VFR COND FOR ALL SITES AS HIGH PRESSURE BUILDS IN FROM THE WEST...AND EVENTUALLY NEAR SCT BY 18Z MONDAY. SOME MVFR CEILINGS AT KSLK FROM 00Z-04Z MON. WINDS CURRENTLY WNW 10-20KTS WITH SOME HIR GUSTS...WILL BECM LIGHTER THRU FORECAST PERIOD TO 10KTS OR LESS BY 00Z MON. HIR TRRN OBSCD AT TIMES. 18Z MONDAY THROUGH THURSDAY...VFR CONDITIONS EXPECTED OVER THE REGION MONDAY AND TUESDAY...AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION FROM THE GREAT LAKES. A WEAK AREA OF LOW PRESSURE WILL MOVE SOUTHEAST FROM THE GREAT LAKES TUESDAY NIGHT AND WEDNESDAY...BRINGING A CHANCE FOR SOME LIGHT SNOW SHOWERS ALONG WITH MVFR/IFR CONDITIONS. ANOTHER RIDGE OF HIGH PRESSURE WILL BUILD EAST FROM THE GREAT LAKES WEDNESDAY NIGHT...BRINGING VFR CONDITIONS TO THE REGION WEDNESDAY NIGHT AND THURSDAY. && .HYDROLOGY... AS OF 0412 AM EDT SUNDAY...WILL EXTEND FLOOD WATCH TO UNTIL THIS AFTERNOON. SMALLER TRIBS CRESTING ONLY NOW...AND OTTER CREEK AT CENTER RUTLAND AND OTHER MAINSTEM RIVERS CONTINUE TO RISE. SOUTHERN VERMONT RECEIVED 1.5 TO 2 INCHES ALL LIQUID OVER THE PAST 24 HOURS...AND WATERWAYS RUNNING HIGH. IN ADDITION TO OPEN WATER FLOOD POTENTIAL...THESE RISES HAVE RIVER ICE BREAKING UP AND MOVING ON CENTRAL AND SOUTHERN VT RIVERS. KNOWN ICE JAM ON THE MAD RIVER AT MORETOWN VT...AND VT HIGHWAY DEPT REPORTS A JAM MOVING DOWN THE FIRST BRANCH OF THE WHITE RIVER ALONG ROUTE 110 IN THE CHELSEA/TUNBRIDGE/SOUTH ROYALTON AREA. COLD AIR SPREADING OVER REGION IS A HELP BY FREEZING UP THE RUNOFF...AND WILL ALLOW RIVERS TO BEGIN TO RECEDE. IN EXTENDED...FORECAST LOOKS GOOD FOR END OF WEEK FOR SOME WELL REGULATED SNOWMELT RUNOFF...40S IN THE DAY AND 20S AT NIGHT WILL HELP MELT SOME SNOW AND GET THE WATER INTO THE RIVERS IN AN ORDERLY FASHION. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...FLOOD WATCH UNTIL 5 PM EDT THIS AFTERNOON FOR VTZ009>012-018- 019. NY...NONE. && $$ SYNOPSIS...HANSON NEAR TERM...BANACOS SHORT TERM...HANSON LONG TERM...HANSON AVIATION...WGH/JN HYDROLOGY...BANACOS ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 1252 PM EST SAT MAR 8 2008 .SYNOPSIS... LOW PRESSURE MOVING INTO NORTHEAST PENNSYLVANIA LATE TODAY WILL BRING A MIXED BAG OF PRECIPITATION TO THE REGION. AS THE LOW MOVES INTO NEW ENGLAND TONIGHT, RAIN AND MIXED PRECIPITATION WILL CHANGE OVER TO SNOW SHOWERS AS GUSTY WINDS BRING IN COLDER AIR. THE SNOW SHOWERS WILL PERSIST ACROSS UPSTATE NEW YORK ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATED...LTL CHG TO CRNT FCST AND WILL LEAVE ALL FLAGS AS IS. AREAS ALONG AND W OF I-81 HAVE SFC TEMPS GNRLY IN THE 30-32 RNG, AND XPCT LTL CHG THIS AFTN. ACRS THESE AREAS, A MIX OF RAIN/FZRA AND SLEET CAN BE XPCTD. AREAS TO THE SE WILL SEE RAIN AS THE PRIMARY PCPN TYPE. POTNL FOR CONVECTION THIS AFTN ACRS THE POCONOS AND SRN CATSKILLS MAY POSE SOME FLASHY HYDRO PRBLMS THIS AFTN/EVNG AND WILL KEEP A CLOSE EYE ON THIS. WINDS WILL PICK UP THIS EVNG BEHIND THE LOW. ISALLOBARIC FIELD LOOKS PRETTY GOOD BUT INITIAL BUFKIT PROFILES SUGGEST LOW END ADVISORY. IN AGREEMENT WITH BUF/ALY TO HOLD OFF ON ANY WIND HEADLINES ATTM...INITIAL THOUGHT IS THAT 20-30G4O WOULD WORK FOR MOST OF THE AREA. GIVEN COMPLEXITY OF FCST ATTM WILL LEAVE HEADLINES AS IS BUT WILL CONSIDER WIND HEADLINES THIS AFTN. PREV BLO... WK SFC LOW THAT DEVELOPED OVR THE DELMARVA EARLY THIS MRNG HAS MVD TO A POSN OFF OF CAPE COD. THIS HAS SERVED TO PULL IN A LITTLE BIT CLDR AIR FOR THE TIME BEING BUT HAS ALSO TAKEN PCPN WITH IT AS IT EXITS. RESPITE FROM THE PCPN WILL BE SHORT-LIVED AS MORE IS MVG QUICKLY NORTH THRU PA WITH LIGHTNING STRIKES ALREADY NOTED OVR CPA. UPPER LOW HAS CLOSED OFF OVR THE TN VALLEY WITH ASSOC SFC LOW MAKING RAPID PROGRESS TO THE NORTH...CURRENTLY LOCATED OVR VA/TN/NC BORDER. SFC TROF AXIS EXTENDS NORTH OF THE CTR AND TWD FA WITH GREATEST PRESSURE FALLS OVR WV AT PRESENT. EXPECT THIS LOW WILL CONTINUE MVG NORTH AND EAST TODAY ALONG BOUNDARY. BOTH NAM/GFS ARE IN GOOD AGREEMENT ON EVENTUAL POSN OF LOW THIS AFTN. ONLY DIFFERENCE RMNS IN THE NAM DEVELOPING SECONDARY LOW ALONG THE COAST THIS AFTN. HOWEVER...WITHIN 6 HRS THE PRIMARILY SFC LOW TAKES OVR. GFS/SUPER ENSEMBLES/RUC DO NOT SEEM TO BE BUYING INTO THIS SOLN AND HAVE THUS SIDED TWD GFS SOLN IN THE PLACEMENT OF THE LOW CTR FOR TODAY. H5 LOW WILL EJECT NORTH TODAY AS NEXT S/WV DROPS INTO NRN PLAINS AND KICKS IT OUT. LOW IS PROGGED TO TAKE ON NEGATIVE TILT AS IT HEADS UP INTO THE OH VALLEY. ALL SHORT AND MEDIUM RANGE GUIDANCE INDICATES THE LOW CTR TRACKING WEST OF THE FA TODAY. H8/H7 CENTERS ALSO EXPECTED TO TRACK THRU WRN NY/FINGER LAKES TODAY. AS H8 LOW TRACKS NORTH...WINDS WILL BACK ARND TO THE SOUTHEAST DRAWING WARMER AIR INTO CNY AFTR ABOUT 15Z. CURRENTLY TEMPS ARE SITTING RIGHT ARND FZG. INITIAL BATCH OF PCPN WILL MV IN BTWN 12Z-15Z. BUFKIT PROFILES FROM THE NAM/GFS/RUC INDICATE A MIX OF SLEET OR FZRA EARLY THIS MRNG...POSSIBLY MIXED WITH SNOW ACROSS THE FAR NORTH AS PROFILE RMNS ISOTHERMAL PER ACARS DATA. AS WARM ADVECTION KICKS IN THE WARM LAYER AT 800MB INCRS TO ARND +5C. FAR SRN AND ERN ZONES WILL RMN ABV FRZG AND EXPECT ALL RAIN TODAY. SOME ELEVATED CONVECTION CAN BE EXPECTED WITH SHOWALTERS DROPPING BLO ZERO AND LAPSE RATES INCRSG TO 6.5-7 FROM 15Z-21Z. FURTHER NORTH...SLEET AND FREEZING RAIN WILL GIVE WAY TO ALL RAIN AFTER ABOUT 15Z ACROSS PARTS OF CNY. HIGHER ELEVATIONS MAY RMN ARND FRZG FOR A GOOD PART OF THE DAY. WITH TEMPS ARND 32F...PCPN MAY HAVE A HARD TIME ACCUMULATING ON SFCS AND EXPECT ICING OF ONLY ONE TENTH OF AN INCH OR SO THRU THE DAY ACROSS THE HILLTOPS. ACROSS THE FINGER LAKES AND FAR NORTH...FREEZING RAIN MAY HOLD ON A LITTLE LONGER AS TEMPS WILL STRUGGLE INTO THE MIDDLE 30S. UP TO ONE QUARTER OF AN INCH WILL BE POSSIBLE ALTHO VALLEY LOCATIONS SHUD WARM UP ENUF TO SEE PLAIN RAIN. THUS...HAVE LEFT WINTER WX ADVISORIES IN PLACE WHERE THEY PREVIOUSLY WERE. DELAWARE COUNTY MAY BE A QUESTION MARK AS TO WHETHER SOME SPOTS MAY SEE SOME ICING BUT HAVE OPTED NOT TO INCLUDE THEM AS OF YET AS MOST OF THE COUNTY SHUD WARM UP FAIRLY QUICKLY ALOFT. WINTER STORM WARNINGS FOR STEUBEN...SCHUYLER... MADISON AND SRN ONEIDA HAVE BEEN DROPPED TO WINTER WX ADVISORIES. VRY LITTLE SNOW IS EXPECTED TODAY AND ICING AMNTS WILL NOT BE ENUF TO PUSH THESE AREAS TO WARNING CRITERIA. REGARDING THE HEAVY RAIN THREAT...H8 JET INCREASES TO 40-50KTS THIS AFTN WITH A SOUTH-SOUTHEAST TRAJECTORY AS H8 LOW MVS NORTH. THIS IN CONJUNCTION WITH SRN STREAM SPEED MAX AND POSSIBLE ELEVATED CONVECTION WILL CONTINUE THE THREAT FOR FLOODING TODAY. CUD SEE SOME URBAN AND SMALL STREAM FLOODING BUT FEEL THE BETTER CHC FOR HVY RAIN HAS SHIFTED A LITTLE TO THE EAST BASED ON TRACK OF SFC LOW AND H8 SPEED MAX. MODELS HV COME IN LIGHTER ON QPF WITH 0.50-1.00 INCHES EXPECTED FROM I-81 CORRIDOR EAST. WITH RIVERS STILL HIGH AND PROGGED TO RISE TO NR/ABV FLOOD STAGE ON THE SUSQUEHANNA AND DELAWARE BEST COURSE OF ACTION IS TO KEEP FLOOD WATCH GOING THRU SUNDAY MORNING. LATER SHIFTS MAY NEED TO CANCEL IT EARLY GIVEN PROGRESS OF HVY RAIN TO THE EAST. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... FCST FOR TONIGHT COMPLICATED WITH REGARD TO SNOWFALL AMNTS/WARNING CRITERIA PCPN. SFC LOW PASSES THRU THIS EVENING AND DRAWS COLD AIR IN VRY QUICKLY. TEMPS ALOFT PLUMMET BHND THE STORM WITH H8 TEMPS DOWN TO NR -15C AFTER 06Z. PCPN WILL CHG TO ALL SNOW OVR MOST OF CNY AFTER 00Z. QPF FROM 00Z NAM/GFS BOTH GIVE ABOUT ONE HALF INCH ACROSS THE FINGER LKS/MOHAWK VALLEY OVERNIGHT. TREMENDOUS LIFT BEING ADVERTISED ALONG WITH RAPIDLY LOWERING SNOW GROWTH LAYER. INITIAL PLAN WAS TO DROP WARNING FOR THE ENTIRE AREA. HOWEVER...WRAP- ROUND OCCASIONALLY HAS A TENDENCY TO INTENSIFY DUE TO THE LAKE INFLUENCE. WITH FAVORABLE SNOW GROWTH AREA...INTENSE LIFT AND PLENTY OF MOISTURE AVAILABLE OVR NRN SECTIONS...HAVE OPTED TO KEEP WARNING GOING FROM YATES THRU ONONDAGA AND NRN ONEIDA. THE BEST CHC FOR 12-HR WARNING CRITERIA ACCUMS WILL BE FROM PENN YAN TO SYRACUSE TO BOONVILLE WITH 5-8 INCHES POSSIBLE. LIMITING FACTOR IN ALL THIS WILL BE THE SPEED AT WHICH THE STORM DEPARTS THE AREA. PCPN WILL ONLY HV ABOUT A 4-6 HR WINDOW TO WORK WITH IN ORDER TO GET WARNING CRITERIA. THE ADVISORY AREA WILL ONLY SEE ABOUT 1-3 INCHES OF SNOW ACCUMS OVRNGT BUT SLEET AND FZRA EXPECTED SAT AFTN WARRANTS KEEPING HEADLINE RUNNING. NEXT CONCERN FOR TONIGHT WILL BE WINDS BHND THE STORM. TIGHT PRESSURE GRADIENT WILL EXIST ARND LOW AS IT CONTINUES TO DEEPEN INTO NRN VT. MODELS HINTING AT H8 WINDS OF 50KTS BLOWING THRU ON BACKSIDE OF SFC LOW. WUD NOT BE SURPRISED TO SEE GUSTS UP TO 45 KTS OVERNIGHT OVR THE HILLTOPS. WIND ADVISORY MAY NEED TO BE HOISTED LATER ON. FOR THE TIME BEING...PREFER TO CVR POTENTIAL IN SUBSEQUENT WINTER WX HEADLINES AND THE HWO. AREAS OF SNOW AND BLOWING SNOW CAN BE EXPECTED TONIGHT - ONE MORE FACTOR IN FAVOR OF KEEPING SOME PORTIONS OF THE WINTER STORM WARNING GOING. THE SNOW SHUD BEGIN TO TAPER OFF AFTER MIDNIGHT AS LOW RAPIDLY MVS NORTH AND EAST. LAKE EFFECT SNOW SHOWERS WILL BE POSSIBLE ON SUNDAY BUT CONDS DO NOT APPEAR TO BE FAVORABLE FOR ADVISORY ACCUMS WITH THE SNOWS. LAKE EFFECT WILL SLOWLY COME TO AN END ON MONDAY AS HIPRES TRIES TO BUILD IN. && .LONG TERM /TUESDAY THROUGH FRIDAY/... WITH FOCUS ON THE SHORT TERM MIXED EVENT ABOUT TO GET UNDERWAY... WE HAVE FOLLOWED THE HPC GUIDANCE WITH THIS FCST UPDATE. IN GENERAL...MED RANGE MODELS SUGGEST THAT THE NORTHERN STREAM WILL INFLUENCE WX ACROSS CNY/NEPA WITH TRANSIENT WEAK SYSTEMS PASSING THROUGH THE AREA. NOTHING AT THIS TIME LOOKS SIGNIFICANT. COLD ENOUGH FOR CHC SOME LAKE EFFECT SNOW SHOWERS LINGERING SUN NITE AND MONDAY. LACK OF SYNOPTIC MOISTURE SHOULD MAKE ANY LES A LIGHT EVENT. WEAK TROF/FRONT PASSAGES TUESDAY NIGHT AND THURSDAY NIGHT INTO FRIDAY WITH CHANCES FOR SNOW SHOWERS AT NIGHT...RAIN SHOWERS DURING THE DAY. HIGH PRESSURE AND DRY CONDITIONS TUESDAY AND WEDS INTO THURS. TEMPS START OFF BELOW NORMAL...THEN DECENT WAA AHEAD OF FRONT THURSDAY NIGHT AND FRIDAY SHOULD BRING TEMPS ABOVE. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... WDSPRD IFR CIGS/VSBYS WILL CONTINUE WITH PERIODS OF RAIN AND FREEZING RAIN THIS AFTERNOON. AS DEEPENING LOW PRESSURE NEARS THE AREA...A DRY SLOT MOVES NORTH FROM CENTRAL VIRGINIA AFTER 21Z. THIS MAY ALLOW FOR BRIEF IMPROVEMENT OF CIGS/VSBYS TO MVFR AND PSBLY VFR AT AVP...ELM AND BGM. SHALLOW COLD LAYER MAY HOLD IN THE IFR FURTHER NORTH AND WEST...ESPLY AS WINDS COME AROUND TO THE NORTH OFF THE LAKE AT ITH. ALSO EXPECT A LULL IN THE PRECIPITATION AFTER 21Z. COLD AIR CHANGES PRECIP TO SNOW SHOWERS TONIGHT. CIGS SHOULD IMPROVE TO MVFR...BUT VSBYS OCNLY MVFR-IFR IN ANY SNOW SHOWERS. LOW PRESSURE MOVES NORTHEAST TONIGHT AND SUNDAY WITH IMPROVEMENT TO VFR. MAIN FLIGHT PROBLEM BEGINNING BY MID EVENING AND CONTINUING INTO SUNDAY WILL BE STRONG WEST-NORTHWEST WINDS. WINDS LIKELY SUSTAINED 20-30 KTS...GUSTING OCNLY 35-40 KTS. OUTLOOK... SUN NITE...MVFR CHC LAKE SNOW SYR-RME. ELSEWHERE VFR. MON...VFR. NO SIG WX. TUES...VFR. NO SIG WX. WED...MVFR-VFR. CHC RAIN OR SNOW SHOWERS. THU...VFR. NO SIG WX. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH SUNDAY MORNING FOR PAZ038>040-043-044-047- 048-072. WINTER WEATHER ADVISORY UNTIL 8 AM EDT SUNDAY FOR PAZ038-039. NY...FLOOD WATCH THROUGH SUNDAY MORNING FOR NYZ009-037-045-046- 055>057-062. WINTER WEATHER ADVISORY UNTIL 8 AM EDT SUNDAY FOR NYZ022>025- 036-037-044>046-055-056. WINTER STORM WARNING UNTIL 8 AM EDT SUNDAY FOR NYZ009-015>018. && $$ AVIATION...JAB ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 638 AM EST SAT MAR 8 2008 .SYNOPSIS... A STORM SYSTEM MOVING UP FROM THE TENNESSEE VALLEY WILL SPREAD A MIX OF SLEET AND FREEZING RAIN INTO CENTRAL NEW YORK THIS MORNING...WITH RAIN EXPECTED OVER NORTHEAST PENNSYLVANIA. AS WARM AIR GETS WRAPPED UP AROUND THE STORM THE MIXED PRECIPITATION IS EXPECTED TO SWITCH OVER TO ALL RAIN BY NOON. SOME HIGHER HILLTOP LOCATIONS MAY EXPERIENCE FREEZING RAIN OFF AND ON THROUGH THE AFTERNOON AS TEMPERATURES HOVER AROUND FREEZING. THE RAIN WILL CHANGE OVER TO SNOW THIS EVENING BEGINNING IN THE FINGER LAKES...AND WORKING SOUTH OVERNIGHT. SNOW ACCUMULATIONS OF 5 TO 8 INCHES WILL BE POSSIBLE OVER PORTIONS OF THE FINGER LAKES TONIGHT...WITH SEVERAL INCHES EXPECTED ACROSS THE SOUTHERN TIER AND SUSQUEHANNA BASIN. NORTHWEST WINDS WILL STRENGTHEN TONIGHT WITH WIND GUSTS OF 35 TO 45 MPH POSSIBLE. THE SNOW WILL TAPER OFF BY MORNING...WITH ONLY A FEW LINGER LAKE EFFECT SNOW SHOWERS EXPECTED EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... WK SFC LOW THAT DEVELOPED OVR THE DELMARVA EARLY THIS MRNG HAS MVD TO A POSN OFF OF CAPE COD. THIS HAS SERVED TO PULL IN A LITTLE BIT CLDR AIR FOR THE TIME BEING BUT HAS ALSO TAKEN PCPN WITH IT AS IT EXITS. RESPITE FROM THE PCPN WILL BE SHORT-LIVED AS MORE IS MVG QUICKLY NORTH THRU PA WITH LIGHTNING STRIKES ALREADY NOTED OVR CPA. UPPER LOW HAS CLOSED OFF OVR THE TN VALLEY WITH ASSOC SFC LOW MAKING RAPID PROGRESS TO THE NORTH...CURRENTLY LOCATED OVR VA/TN/NC BORDER. SFC TROF AXIS EXTENDS NORTH OF THE CTR AND TWD FA WITH GREATEST PRESSURE FALLS OVR WV AT PRESENT. EXPECT THIS LOW WILL CONTINUE MVG NORTH AND EAST TODAY ALONG BOUNDARY. BOTH NAM/GFS ARE IN GOOD AGREEMENT ON EVENTUAL POSN OF LOW THIS AFTN. ONLY DIFFERENCE RMNS IN THE NAM DEVELOPING SECONDARY LOW ALONG THE COAST THIS AFTN. HOWEVER...WITHIN 6 HRS THE PRIMARILY SFC LOW TAKES OVR. GFS/SUPER ENSEMBLES/RUC DO NOT SEEM TO BE BUYING INTO THIS SOLN AND HAVE THUS SIDED TWD GFS SOLN IN THE PLACEMENT OF THE LOW CTR FOR TODAY. H5 LOW WILL EJECT NORTH TODAY AS NEXT S/WV DROPS INTO NRN PLAINS AND KICKS IT OUT. LOW IS PROGGED TO TAKE ON NEGATIVE TILT AS IT HEADS UP INTO THE OH VALLEY. ALL SHORT AND MEDIUM RANGE GUIDANCE INDICATES THE LOW CTR TRACKING WEST OF THE FA TODAY. H8/H7 CENTERS ALSO EXPECTED TO TRACK THRU WRN NY/FINGER LAKES TODAY. AS H8 LOW TRACKS NORTH...WINDS WILL BACK ARND TO THE SOUTHEAST DRAWING WARMER AIR INTO CNY AFTR ABOUT 15Z. CURRENTLY TEMPS ARE SITTING RIGHT ARND FZG. INITIAL BATCH OF PCPN WILL MV IN BTWN 12Z-15Z. BUFKIT PROFILES FROM THE NAM/GFS/RUC INDICATE A MIX OF SLEET OR FZRA EARLY THIS MRNG...POSSIBLY MIXED WITH SNOW ACROSS THE FAR NORTH AS PROFILE RMNS ISOTHERMAL PER ACARS DATA. AS WARM ADVECTION KICKS IN THE WARM LAYER AT 800MB INCRS TO ARND +5C. FAR SRN AND ERN ZONES WILL RMN ABV FRZG AND EXPECT ALL RAIN TODAY. SOME ELEVATED CONVECTION CAN BE EXPECTED WITH SHOWALTERS DROPPING BLO ZERO AND LAPSE RATES INCRSG TO 6.5-7 FROM 15Z-21Z. FURTHER NORTH...SLEET AND FREEZING RAIN WILL GIVE WAY TO ALL RAIN AFTER ABOUT 15Z ACROSS PARTS OF CNY. HIGHER ELEVATIONS MAY RMN ARND FRZG FOR A GOOD PART OF THE DAY. WITH TEMPS ARND 32F...PCPN MAY HAVE A HARD TIME ACCUMULATING ON SFCS AND EXPECT ICING OF ONLY ONE TENTH OF AN INCH OR SO THRU THE DAY ACROSS THE HILLTOPS. ACROSS THE FINGER LAKES AND FAR NORTH...FREEZING RAIN MAY HOLD ON A LITTLE LONGER AS TEMPS WILL STRUGGLE INTO THE MIDDLE 30S. UP TO ONE QUARTER OF AN INCH WILL BE POSSIBLE ALTHO VALLEY LOCATIONS SHUD WARM UP ENUF TO SEE PLAIN RAIN. THUS...HAVE LEFT WINTER WX ADVISORIES IN PLACE WHERE THEY PREVIOUSLY WERE. DELAWARE COUNTY MAY BE A QUESTION MARK AS TO WHETHER SOME SPOTS MAY SEE SOME ICING BUT HAVE OPTED NOT TO INCLUDE THEM AS OF YET AS MOST OF THE COUNTY SHUD WARM UP FAIRLY QUICKLY ALOFT. WINTER STORM WARNINGS FOR STEUBEN...SCHUYLER... MADISON AND SRN ONEIDA HAVE BEEN DROPPED TO WINTER WX ADVISORIES. VRY LITTLE SNOW IS EXPECTED TODAY AND ICING AMNTS WILL NOT BE ENUF TO PUSH THESE AREAS TO WARNING CRITERIA. REGARDING THE HEAVY RAIN THREAT...H8 JET INCREASES TO 40-50KTS THIS AFTN WITH A SOUTH-SOUTHEAST TRAJECTORY AS H8 LOW MVS NORTH. THIS IN CONJUNCTION WITH SRN STREAM SPEED MAX AND POSSIBLE ELEVATED CONVECTION WILL CONTINUE THE THREAT FOR FLOODING TODAY. CUD SEE SOME URBAN AND SMALL STREAM FLOODING BUT FEEL THE BETTER CHC FOR HVY RAIN HAS SHIFTED A LITTLE TO THE EAST BASED ON TRACK OF SFC LOW AND H8 SPEED MAX. MODELS HV COME IN LIGHTER ON QPF WITH 0.50-1.00 INCHES EXPECTED FROM I-81 CORRIDOR EAST. WITH RIVERS STILL HIGH AND PROGGED TO RISE TO NR/ABV FLOOD STAGE ON THE SUSQUEHANNA AND DELAWARE BEST COURSE OF ACTION IS TO KEEP FLOOD WATCH GOING THRU SUNDAY MORNING. LATER SHIFTS MAY NEED TO CANCEL IT EARLY GIVEN PROGRESS OF HVY RAIN TO THE EAST. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... FCST FOR TONIGHT COMPLICATED WITH REGARD TO SNOWFALL AMNTS/WARNING CRITERIA PCPN. SFC LOW PASSES THRU THIS EVENING AND DRAWS COLD AIR IN VRY QUICKLY. TEMPS ALOFT PLUMMET BHND THE STORM WITH H8 TEMPS DOWN TO NR -15C AFTER 06Z. PCPN WILL CHG TO ALL SNOW OVR MOST OF CNY AFTER 00Z. QPF FROM 00Z NAM/GFS BOTH GIVE ABOUT ONE HALF INCH ACROSS THE FINGER LKS/MOHAWK VALLEY OVERNIGHT. TREMENDOUS LIFT BEING ADVERTISED ALONG WITH RAPIDLY LOWERING SNOW GROWTH LAYER. INITIAL PLAN WAS TO DROP WARNING FOR THE ENTIRE AREA. HOWEVER...WRAP- ROUND OCCASIONALLY HAS A TENDENCY TO INTENSIFY DUE TO THE LAKE INFLUENCE. WITH FAVORABLE SNOW GROWTH AREA...INTENSE LIFT AND PLENTY OF MOISTURE AVAILABLE OVR NRN SECTIONS...HAVE OPTED TO KEEP WARNING GOING FROM YATES THRU ONONDAGA AND NRN ONEIDA. THE BEST CHC FOR 12-HR WARNING CRITERIA ACCUMS WILL BE FROM PENN YAN TO SYRACUSE TO BOONVILLE WITH 5-8 INCHES POSSIBLE. LIMITING FACTOR IN ALL THIS WILL BE THE SPEED AT WHICH THE STORM DEPARTS THE AREA. PCPN WILL ONLY HV ABOUT A 4-6 HR WINDOW TO WORK WITH IN ORDER TO GET WARNING CRITERIA. THE ADVISORY AREA WILL ONLY SEE ABOUT 1-3 INCHES OF SNOW ACCUMS OVRNGT BUT SLEET AND FZRA EXPECTED SAT AFTN WARRANTS KEEPING HEADLINE RUNNING. NEXT CONCERN FOR TONIGHT WILL BE WINDS BHND THE STORM. TIGHT PRESSURE GRADIENT WILL EXIST ARND LOW AS IT CONTINUES TO DEEPEN INTO NRN VT. MODELS HINTING AT H8 WINDS OF 50KTS BLOWING THRU ON BACKSIDE OF SFC LOW. WUD NOT BE SURPRISED TO SEE GUSTS UP TO 45 KTS OVERNIGHT OVR THE HILLTOPS. WIND ADVISORY MAY NEED TO BE HOISTED LATER ON. FOR THE TIME BEING...PREFER TO CVR POTENTIAL IN SUBSEQUENT WINTER WX HEADLINES AND THE HWO. AREAS OF SNOW AND BLOWING SNOW CAN BE EXPECTED TONIGHT - ONE MORE FACTOR IN FAVOR OF KEEPING SOME PORTIONS OF THE WINTER STORM WARNING GOING. THE SNOW SHUD BEGIN TO TAPER OFF AFTER MIDNIGHT AS LOW RAPIDLY MVS NORTH AND EAST. LAKE EFFECT SNOW SHOWERS WILL BE POSSIBLE ON SUNDAY BUT CONDS DO NOT APPEAR TO BE FAVORABLE FOR ADVISORY ACCUMS WITH THE SNOWS. LAKE EFFECT WILL SLOWLY COME TO AN END ON MONDAY AS HIPRES TRIES TO BUILD IN. && .LONG TERM /TUESDAY THROUGH FRIDAY/... WITH FOCUS ON THE SHORT TERM MIXED EVENT ABOUT TO GET UNDERWAY... WE HAVE FOLLOWED THE HPC GUIDANCE WITH THIS FCST UPDATE. IN GENERAL...MED RANGE MODELS SUGGEST THAT THE NORTHERN STREAM WILL INFLUENCE WX ACROSS CNY/NEPA WITH TRANSIENT WEAK SYSTEMS PASSING THROUGH THE AREA. NOTHING AT THIS TIME LOOKS SIGNIFICANT. COLD ENOUGH FOR CHC SOME LAKE EFFECT SNOW SHOWERS LINGERING SUN NITE AND MONDAY. LACK OF SYNOPTIC MOISTURE SHOULD MAKE ANY LES A LIGHT EVENT. WEAK TROF/FRONT PASSAGES TUESDAY NIGHT AND THURSDAY NIGHT INTO FRIDAY WITH CHANCES FOR SNOW SHOWERS AT NIGHT...RAIN SHOWERS DURING THE DAY. HIGH PRESSURE AND DRY CONDITIONS TUESDAY AND WEDS INTO THURS. TEMPS START OFF BELOW NORMAL...THEN DECENT WAA AHEAD OF FRONT THURSDAY NIGHT AND FRIDAY SHOULD BRING TEMPS ABOVE. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... PRECIP MOVING BACK INTO ALL TAF SITES THIS MORNING. CONDITIONS WILL BE A CHALLENGE, BOTH FOR FLYING AND FOR FORECASTING. WILL LIKELY SEE AN AVERAGE OF IFR CONDITIONS TODAY, ALTHOUGH FLUCTUATIONS ON EITHER SIDE ARE EXPECTED. LOWEST CONDITIONS LIKELY AT HIGHER ELEVATIONS OF KBGM AND KITH WHERE LIFR WILL BE COMMON. A MIX OF PRECIP THIS MORNING AT KSYR, KITH, KELM, KBGM...CHANGING TO ALL RAIN BY LATE THIS MORNING. AT KAVP, ALL RAIN...BUT THERE ARE A FEW TSRA TO THE SOUTH AND WEST OF THE STATION, SO HAVE INCLUDED A CB GROUP FOR A FEW HOURS THIS MORNING. PRECIP CHANGES OVER TO SNOW THIS EVENING AND TAPERS OFF, WITH GENERAL IMPROVEMENT TO MVFR, AND POSSIBLY EVEN VFR DURING THE OVERNIGHT. NORTH TO NORTHEAST WINDS TODAY, 10 KTS OR LESS...WILL INCREASE OUT OF THE NORTHWEST TONIGHT, 15 TO 25 KTS WITH GUSTS TO 30 KTS. OUTLOOK... SUN...VFR. NO SIG WX. MON...VFR. NO SIG WX. TUES...MVFR...CHC SNOW SHOWERS. WED...VFR. NO SIG WX. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH SUNDAY MORNING FOR PAZ038>040-043-044-047- 048-072. WINTER WEATHER ADVISORY UNTIL 8 AM EDT SUNDAY FOR PAZ038-039. NY...FLOOD WATCH THROUGH SUNDAY MORNING FOR NYZ009-037-045-046- 055>057-062. WINTER WEATHER ADVISORY UNTIL 8 AM EDT SUNDAY FOR NYZ022>025- 036-037-044>046-055-056. WINTER STORM WARNING UNTIL 8 AM EDT SUNDAY FOR NYZ009-015>018. && $$ SYNOPSIS...PVB NEAR TERM...PVB SHORT TERM...PVB LONG TERM...JAB AVIATION...JML/TAC ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 845 PM CST SAT MAR 8 2008 .SHORT TERM... FORECAST CHALLENGE CONCERNS CLOUD TRENDS/TEMPERATURES AND RESIDUAL SNOW CHANCES. RETURNS FROM KMVX-88D CONTINUE TO DIMINISH AS WAVE ROTATING AROUND UPPER LOW SHIFTS SOUTH. ANY MINOR RESTRICTION TO VISIBILITY CONFINED TO EASTERN FORECAST AREA. WILL CONTINUE ONGOING TRENDS OF DIMINISHING ANY SNOWFALL TO FLURRIES AS EVENING GOES ON. CLOUD TRENDS A LITTLE MORE TRICKY. BINOVC EARLIER THIS EVENING BEGINNING TO FILL IN AND CLOUDS LIKELY TO HOLD IN MOST OF OVERNIGHT. RUC DOES SHOW SOME SUBTLE DRYING ACROSS NORTHERN FA LATE TONIGHT. THERMAL ADVECTION PRETTY NEUTRAL AS UPPER LOW DRIFTS SOUTHWARD AND TEMPERATURES WILL HINGE GREATLY ON CLOUD COVER. WILL NUDGE TEMPERATURES UP A FEW DEGREES BUT WILL KEEP COLDEST TEMPERATURES ACROSS NORTH WHICH WILL SEE BEST CHANCES FOR CLEARING. && .AVIATION...CIGS AND VSBY IMPROVING WITH ANY MVFR CIGS CONFINED TO AREAS EAST OF VALLEY. EXPECT IMPROVING TRENDS TO CONTINUE OVERNIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ VOELKER nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 1014 PM CDT SUN MAR 9 2008 .UPDATE... CONVECTIVE COMPLEX ASSOCIATED WITH LEAD SHRTWV HAS MOVED EAST OF AREA WITH STRONGEST CONVECTION VCNTY STALLED FRONT STRETCHING FROM SOUTH OF MIDLAND TO NEAR WICHITA FALLS INTO SOUTH CENTRAL OK. THIS ACTIVITY SUPPORTED BY SOUTHERLY LLJ AS SEEN ON VWP/PROFILER NETWORK ACROSS WEST CENTRAL AND CENTRAL TX. TRAILING LOBE OF ENERGY WEST OF EL PASO WILL ROTATE ACROSS BIG BEND OVERNIGHT KEEPING FOCUS FOR ASCENT ACROSS THE TRANS PECOS INTO THE CONCHO VALLEY AND HILL COUNTRY. LOCALLY...OUTFLOW FROM CONVECTION HAS PUSHED HIGHER DEWPOINT AIR WESTWARD INTO SOUTHEAST CORNER. MODELS BRING THIS MOISTURE WESTWARD ALONG SOUTHERN EDGE OF CAPROCK BY MORNING DESPITE BEING OPPOSED BY MORE NORTHERLY SURFACE WINDS. AS PRESSURES FALL ALONG THE LEE OF THE ROCKIES IN RESPONSE TO NEXT SHRTWV DIVING QUICKLY SOUTHWARD ON MON...SOME OF THIS MOISTURE COULD BE PULLED NORTHWARD ACROSS THE SOUTH PLAINS. EXPECT LITTLE AFFECT ON LATER PERIODS OF FORECAST SO HAVE UPDATED NIGHTTIME PERIOD TO REDUCE POPS ACROSS SE CORNER AND BRING SLIGHTLY HIGHER DEWPOINTS/WARMER OVERNIGHT LOWS ACROSS SMALL SECTION WHERE MOISTURE HAS INCREASED. && .AVIATION... LIKELHOOD OF MVFR CIGS AT KLBB CONTINUE TO BE POSSIBLE DESIPITE PERSISTENT DRYING IN NORTHERLY SURFACE FLOW ON THE CAPROCK. SOME LOW LEVEL MOISTURE HAS BEEN ENRICHED COURTESY OF OUTFLOW FROM CONVECTIVE COMPLEXT ACROSS BIG COUNTRY. SHORT TERM MODELS NAM/RUC BRING MOISTURE WESTWARD OVERNIGHT AT 850 MB ON CONTINUED E/NE WINDS IN VERY WEAK UPGLIDE. ANY LOW CLOUD FORMATION SHOULD BE SHORT LIVED AND SCATTERED AND WITH THAT CURRENTLY IN TAF WILL LEAVE IT FOR 06Z ISSUANCE. && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 24 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 908 PM CST SAT MAR 8 2008 .UPDATE...WATER VAPOR DEPICT/NWP MODELS PROG THE APPROACH OF AN UPPER LEVEL DISTURBANCE. THE GFS PROGS THE DEVELOPMENT OF THE LOW LEVEL JET OVERNIGHT AND ANTICIPATE VERTICAL MIXING OVR THE WATERS. FURTHER...THE NAM/GFS/RUC PROG 20KT SFC WIND OVR THE WATERS BY 06Z SUN. WL INTRODUCE SCA FOR THE COASTAL WATERS FOR TNGT...AND ANTICIPATE SCEC CONDITIONS FOR THE BAYS. WL MAKE SLIGHT UPWARD ADJUSTMENTS TO OVERNIGHT TEMPS FOR THE ERN CWFA BASED ON CURRENT/EXPECTED DEW POINTS. BASED ON THE THERMODYNAMIC PROFILE OVERNIGHT (INCREASING SFC THETA-E VALUES COUPLED WITH EXTREMELY DRY ALOFT) PATCHY FOG COULD OCCUR OVR THE ERN CWFA OVERNIGHT. HWR...EXPECT WIND TO PRECLUDE SUCH. && .AVIATION...UPPER TROF WILL MOVE INTO THE SOUTHERN ROCKIES AND RESULTANT PRESSURE OVER WEST TEXAS WILL LOWER FURTHER OVERNIGHT INTO SUNDAY. AS A RESULT...SOUTHERLY LOW LEVEL WINDS WILL ADVECT LOWER TROPOSPHERIC MOISTURE INTO THE REGION DURING THE NEXT 48 HOURS. 35 TO 40 KNOT LLJ WILL DEVELOP ACROSS DEEP SOUTH TEXAS...SOUTHERN COASTAL PLAINS AND SOUTHERN COASTAL BEND BY 12Z. BKN TO OVC SKIES WILL QUICKLY DEVELOP DURING THE PRE-DAWN HOURS SUNDAY...MAINLY EAST OF HIGHWAY 281. THIS LOW LEVEL MOISTURE IS EVIDENT RIDING UP NORTHWARD ALONG THE COAST OF TAMAULIPAS MEXICO THIS EVENING. VFR CONDITIONS WILL PREVAIL THRU SUNRISE. BOTH CIRRIFORM CLOUDS WILL INCREASE FROM THE WEST SUNDAY IN CONCERT WITH AREAS OF MVFR LOW LVL CIGS JUST BEFORE SUNRISE...MAINLY EAST OF A LINE FROM FALFURRIAS TO THREE RIVERS. BKN CIGS OF 3-5 THOUSAND FEET WILL PREVAIL THRU THE MORNING DAYLIGHT HOURS THROUGH THE EARLY EVENING WITH SOUTHEASTERLY SURFACE WINDS AT 15 TO 25 KNOTS EXPECTED AFT 15Z WITH SOME HIGHER GUSTS BETWEEN 30 AND 35 KNOTS OVER THE COASTAL BEND AND COASTAL PLAINS. COULD SEE A FEW LIGHT STRAY SHOWERS OR SPRINKLES ON SUN... BUT NOT WIDESPREAD ENOUGH TO MENTION IN THE TAF. WEST OF HIGHWAY 16...VFR CONDITIONS ARE ANTICIPATED THROUGH THE ENTIRE TAF PERIOD AT COTULLA AND LAREDO WITH BREEZY WINDS DEVELOPING AFT 15Z. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 52 73 62 74 57 / 10 10 40 60 60 VICTORIA 45 70 59 70 53 / 10 20 50 80 60 LAREDO 54 82 62 78 58 / 0 0 20 50 20 ALICE 47 74 59 75 55 / 10 10 30 60 50 ROCKPORT 55 70 63 69 58 / 10 10 40 70 70 COTULLA 44 77 61 75 51 / 0 10 30 60 30 KINGSVILLE 50 74 60 75 58 / 10 10 30 50 50 NAVY CORPUS 56 71 64 72 59 / 10 10 40 60 60 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY FROM MIDNIGHT CST TONIGHT TO 7 AM CDT SUNDAY FOR THE FOLLOWING ZONES: COASTAL WATERS BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS BAFFIN BAY TO PORT ARANSAS 20 TO 60 NM...WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL 20 TO 60 NM. && $$ WC/87...SHORT TERM SC/70...AVIATION tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE SPOKANE WA 1112 AM PDT SUN MAR 9 2008 .SYNOPSIS... HIGH PRESSURE WILL BE OVER THE INLAND NORTHWEST TODAY. A PACIFIC STORM SYSTEM WILL PASS THROUGH THE REGION TONIGHT THROUGH TUESDAY WITH WARMER YET WETTER CONDITIONS. A RIDGE WILL RETURN BY WEDNESDAY ...ALTHOUGH A MOIST WESTERLY FLOW WILL MOVE INTO THE REGION BY THE END OF THE WORK WEEK. && .DISCUSSION... REST OF TODAY...HIGH PRESSURE IS SITUATED AT THE SFC (CENTERED OVER IDAHO/GREAT BASIN AREA). COUPLED WITH A MOIST BL (UP TO ABOUT 900 MB)...A LIGHT SE FLOW AT THE SFC AND WEAK WAA AT 850 HELPING TO MAINTAIN AN INVERSION....THIS SET-UP LED TO THE DEVELOPMENT STRATUS AND FOG (LOCALLY DENSE) A LITTLE PAST MIDNIGHT ACROSS PORTIONS OF THE SPOKANE/C`DA AREA AND SOME NRN VALLEYS...AS WELL AS ACROSS THE L-C AREA. THE MOIST LAYER IS ABOUT 400-500 FEET DEEP. THE NAM AND RUC MODEL SOUNDINGS (WHICH INITIALIZED WELL COMPARED TO THE 12Z SOUNDING) INDICATE THE INVERSION BREAKING TOWARD 18Z AND BETTER MIXING TO BREAK UP THIS FOG/STRATUS. SOME OF THE DEEPER VALLEYS MAY TAKE UNTIL LATE AFTERNOON TO COMPLETELY LIFT OUT THE STRATUS. HOWEVER MID TO HIGH CLOUDS ARE STREAMING IN ALOFT. ON LARGER A SCALE...A LONG-WAVE TROUGH IN THE GULF OF AK HAS THE PACIFIC NW IN A WSW FLOW. A STREAM OF MOISTURE AND A COUPLE SHORT-WAVE SYSTEMS ARE PIVOTING AROUND THAT FEATURE. ONE SHORT-WAVE IS SLIPPING INTO BC. MID AND HIGH MOISTURE AND ASSOCIATED CLOUDS ARE SPREADING IN FROM THE WEST WITH THIS FEATURE. MOST OF THE SYNOPTIC SCALE LIFT ASSOCIATED WITH THE SHORT-WAVE REMAINS NORTH OF THE CANADIAN BORDER. AN ELONGATED/WEAK VORT MAX WAS PASSING EAST OF THE CASCADES AND A SECOND WEAK VORT MAX ONTO THE WA COAST TOWARD 00Z. THIS COMES WITH SOME DEEPENING ON MOISTURE INTO THE CASCADES AND SOME ISENTROPIC ASCENT AS A WARM FRONT STARTS TO LIFT NORTH. THIS WILL MEAN A SLIGHT CHANCE FOR SHOWERS NEAR THE CASCADES LATE. OTHERWISE THE REST OF TODAY WILL BE DRY. TEMPERATURES ARE RUNNING BELOW GUIDANCE AND FORECAST. VALUES WERE CUT BACK 2-3 DEGREES /J && .AVIATION... FOG/STRATUS WILL LIFT TO MAINLY VFR/LCL MVFR CIGS SUNDAY AFTERNOON. THE NEXT SYSTEM MOVING IN TONIGHT AND MONDAY WILL BRING IN MID/HIGH CLOUDS...GRADUALLY LOWERING BY LATE AM TO MIDDAY MONDAY. HOWEVER...PRIMARILY VFR CONDITIONS FCST TO 18Z. RISK FOR LIGHT PRECIP WILL BEGIN TO SPREAD IN FROM THE WEST AFTER 12-15Z...WITH LCL MVFR CIGS WITH PRECIP. /J && .PRELIMINARY POINT TEMPS/POPS... SPOKANE 49 37 53 42 46 29 / 0 0 20 80 40 20 COEUR D`ALENE 46 35 53 42 46 29 / 10 0 20 80 60 30 PULLMAN 52 38 56 44 48 31 / 0 0 10 80 50 20 LEWISTON 57 40 63 47 54 35 / 0 0 10 80 50 10 COLVILLE 50 34 50 39 46 28 / 0 10 40 70 40 20 SANDPOINT 47 33 49 40 46 29 / 10 10 30 80 60 40 KELLOGG 46 34 55 41 47 30 / 10 0 20 90 60 50 MOSES LAKE 56 39 55 41 55 31 / 0 0 30 40 10 10 WENATCHEE 52 39 52 42 55 33 / 0 10 30 40 10 10 OMAK 51 34 50 38 53 26 / 0 20 50 50 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...NONE. WA...NONE. && $$ wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 252 PM CDT SUN MAR 9 2008 .SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT FORECAST CONCERNS ARE ON SNOW CHANCES TONIGHT AS WELL AS CLOUD TRENDS...THEN TEMPERATURES THROUGH WEDNESDAY. 18Z SURFACE ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE NEAR KDBQ WITH A TRAILING COLD FRONT SOUTH INTO NORTHERN MISSOURI. MEANWHILE A TROUGH OF LOW PRESSURE STRETCHES FROM THE LOW NORTHWEST ACROSS THE FORECAST AREA AND INTO SOUTHERN MINNESOTA. THIS TROUGH HAS BEEN THE FOCUS FOR VERY LIGHT SNOW AND FLURRIES ACROSS THE AREA TODAY. 09.12Z SHORT RANGE MODELS IN GOOD AGREEMENT THROUGH THE PERIOD. GFS CONTINUES TO HAVE MORE MOISTURE AND RESULTANT QPF ON TUESDAY AS A SHORT WAVE TROUGH MOVES ACROSS NORTHERN MINNESOTA/WISCONSIN INTO THE GREAT LAKES. IT IS THE ONLY ONE WITH QPF INTO THE AREA AND THUS DISCOUNTING THIS SOLUTION. IN THE NEAR TERM...BOTH THE GFS/NAM AS WELL AS THE RUC SHOWING VERY WEAK QG CONVERGENCE THIS EVENING ALONG THE TROUGH ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN. ALL THE MODELS CONTINUE TO SHOW VERY LIGHT QPF IN THIS REGION. HOWEVER...WITH LATEST RADAR TRENDS HAVE BACKED OFF TO JUST FLURRIES THROUGH THE EVENING HOURS. NEXT QUESTION IS CLOUDS. SATELLITE TRENDS SHOWING QUITE A FEW HOLES IN THE CLOUDS OVERHEAD WITH CLEARING SKIES ALREADY TAKING PLACE ACROSS THE NORTHERN ZONES.. MODEL RELATIVE HUMIDITY TRENDS SHOW A SLOW DECREASE IN THE CLOUDS OVERNIGHT AS THE TROUGH SAGS SOUTHWARD. HIGH PRESSURE THEN DOMINATES THE WEATHER MONDAY AND MONDAY NIGHT WITH QUIET WEATHER EXPECTED. A SHORTWAVE MOVES ACROSS NORTHERN MINNESOTA AND NORTHERN WISCONSIN TUESDAY...BUT MOISTURE VERY LIMITED SO ANY PRECIPITATION WILL REMAIN WELL NORTH OF THE AREA. AS THE HIGH SLIDES SOUTHEAST OF THE AREA WARM ADVECTION WILL BEGIN... DRAWING WARMER AIR BACK INTO THE REGION FOR TUESDAY AND WEDNESDAY. 850MB TEMPERATURES WARM TO THE PLUS SIDE OF ZERO AND WITH A DECENT AMOUNT OF SUN WILL SEE TEMPERATURES REBOUND BACK TO NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS FOR BOTH TUESDAY AND WEDNESDAY. GUIDANCE VALUES SHOWING ALL AREAS TO RISE INTO THE 40S BOTH DAYS. WITH THE CLEAR SKIES OVERNIGHT LOWS WILL DROP BACK BELOW THE FREEZING MARK SO MELTING TEMPERATURES TO BE CONFINED TO DAYTIME HOURS. .LONG TERM...THURSDAY THROUGH SUNDAY MEDIUM RANGE MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THIS PERIOD. NORTHWEST FLOW TO DOMINATE THROUGH SATURDAY BEFORE LARGE TROUGH PUSHES INTO THE WESTERN CONUS...BUCKLING THE FLOW ACROSS THE CENTRAL CONUS. ENSEMBLES AND DETERMINISTIC 09.06Z GFS AND 09.00Z ECMWF SHOW SHORTWAVE ADVANCING ALONG THE CANADIAN BORDER ON THURSDAY...DRAGGING A COLD FRONT ACROSS THE GREAT LAKES... WHICH WILL USHER IN ANOTHER SHOT OF COOLER AIR FOR THE WEEKEND. THERMAL PROFILES INDICATE SOME WARMER AIR BEING ADVECTED INTO THE AREA THURSDAY AND THURSDAY NIGHT AND WILL CONTINUE TO MENTION RAIN OR SNOW CHANCES...ALBEIT ANY PRECIPITATION THAT FALLS LOOKS TO BE IN THE LIGHT SIDE. RABERDING && .AVIATION... AN INVERTED TROUGH CONTINUES TO RESIDE ACROSS SOUTHEAST MINNESOTA... NORTHEAST IOWA...AND THE SOUTHERN HALF OF WISCONSIN. THIS TROUGH WAS PRODUCING A SCATTERED TO BROKEN MVFR DECK /1500 TO 2500 FEET/ AND SCATTERED SNOW SHOWERS WHICH REDUCED VISIBILITIES TO 3 MILES IN A FEW PLACES. THE 09.12Z MODELS CONTINUE TO SHOW THAT THIS TROUGH WILL MOVE SLOWLY SOUTHEAST OUT OF THE AREA ON MONDAY MORNING. AS THIS OCCURS...THE FLOW WILL GRADUALLY BECOME ANTICYCLONIC AND THE CLOUDS WILL GRADUALLY BREAK UP. AT THIS TIME...IT LOOKS LIKE THIS SHOULD OCCUR BETWEEN 10Z AND 14Z MONDAY. HOWEVER...I AM A BIT CONCERNED THAT THIS MAY BECOME SOONER...BECAUSE THERE ARE SOME HOLES IN THE CLOUDS. ONCE THESE CLOUDS BREAK UP...WE SHOULD VFR CONDITIONS THROUGH THE REMAINDER OF MONDAY. BOYNE && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ wi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 829 AM CST SAT MAR 8 2008 .UPDATE...HAVE ISSUED A LAKE EFFECT SNOW ADVISORY FOR MILWAUKEE...RACINE AND KENOSHA COUNTIES AS IMPRESSIVE LAKE SNOW BAND WITH TERMINAL DOPPLER RETURNS AROUND 30DBZ TO PERSIST OVER THESE COUNTIES INTO EARLY AFTERNOON. CURRENT WRF4G MAINTAINS SNOW BAND ALONG LAKESHORE AREAS INTO EARLY AFTERNOON. WITH HIGH SNOW RATIOS EXPECT 3 TO 6 INCHES WITH HIGHER AMOUNTS CLOSE TO LAKE SHORE. && .PREV DISCUSSION... /ISSUED 316 AM CST SAT MAR 8 2008/ .DISCUSSION...FORECAST FOCUS IS ON LAKE EFFECT SNOW SHOWERS THIS MORNING...THEN ON GENERALLY QUIET WEATHER THROUGH WEDNESDAY. IT APPEARS THAT HEAVY LAKE EFFECT SNOW SHOWERS ARE UNLIKELY TO OCCUR THIS MORNING FOR A VARIETY OF REASONS. RUC AND GFS SOUNDINGS INDICATE A LOW LEVEL INVERSION AT AROUND 1K FEET...AND ANOTHER INVERSION AROUND 4K FEET. THE COLUMN APPEARS TO BE QUITE DRY ABOVE 4K FEET WITH LITTLE OR NO OMEGA. ALSO...THE FETCH IS NOT OPTIMAL AND LAKE INDUCED MOISTURE IS VERY LIMITED. THERE IS NO ORGANIZED BANDS SHOWING ON RADAR AT THIS TIME...JUST MULTIPLE VERY WEAK BANDS GENERALLY NORTH OF CWA. THESE CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE MORNING HOURS...WITH ONLY WEAK UNORGANIZED SNOW BANDS AFFECTING THE AREAS CLOSE TO LAKE MICHIGAN. WITH A 25 TO 1 RATIO...I EXPECT AREAS NEAR LAKE MICHIGAN COULD SEE AN INCH OR 2 AT MOST THIS MORNING...AND ONLY SCATTERED VERY LIGHT SNOW SHOWERS THIS AFTERNOON. A VERY WEAK AREA OF LOW PRESSURE IS FORECAST TO DRIFT ACROSS SOUTHERN SECTIONS OF THE CWA TONIGHT AND SUNDAY. HOWEVER...THERE IS VERY LITTLE DYNAMICS AND QPF ASSOCIATED WITH THE SYSTEM. THERE MAY BE A BRIEF PERIOD OF ISENT LIFT BETWEEN 00Z AND 06Z THIS EVENING...BUT LITTLE ELSE TO RECOMMEND THE SYSTEM. I THINK SOME LIGHT SNOW AND FLURRIES WILL OCCUR...BUT WIDESPREAD MEASURABLE SNOW IS UNLIKELY AT THIS TIME. POPS WILL REMAIN LOW. QUIET WEATHER IS EXPECTED SUNDAY NIGHT THROUGH WEDNESDAY. THE COLUMN REMAINS QUITE DRY WITH NO DYNAMICS. MODELS ARE CONSISTENT WITH STRONG WARMING TREND BEGINING MONDAY...WITH TEMPERATURES TUESDAY AND WEDNESDAY ABOVE SEASONAL NORMALS. AVIATION...PREDOMINANT SINGLE LAKE EFFECT SNOW BAND IS PUSHING INLAND AS NE GRADIENT FLOW OVERCOMING WEAKER NNW FLOW ON WRN SIDE OF LK MI. SINGLE BAND IS EVOLVING INTO SHORTER MULITPLE BANDS...MAINLY FROM SHEBOYGAN NORTH. EXPECT VFR CIGS AND VSBYS WITH BRIEF MVFR CONDITIONS AS THE LIGHT SNOW BANDS MOVE ACROSS KMKE AND KENW THROUGH 18Z...THEN BANDS AND CLOUDS PUSH OUT OVER LAKE MICHIGAN. KMSN SHOULD SEE PREVAILING VFR CONDITIONS THROUGH THE PERIOD. MARINE...ALTERED GENERAL SMALL CRAFT ADVISORY TO A SMALL CRAFT FOR HAZARDOUS SEAS UNTIL 00Z SAT AS WINDS HAVE FALLEN BELOW CRITERIA...BUT WAVES TO REMAIN ABOVE CRITERIA AT 4 TO 6 FEET...MAINLY TOWARD OPEN WATER THEN SUBSIDE THROUGH THE AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...LAKE EFFECT SNOW ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR WIZ066-071-072. LM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM CST THIS AFTERNOON FOR LMZ643>646. && $$ SHORT/LONG TERM...17/ZAJDEL AVIATION/MARINE...20/GEHRING wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 447 AM CST SAT MAR 8 2008 .SHORT TERM...TODAY THROUGH SUNDAY. SOME LAKE EFFECT SNOW SHOWERS LIKELY TODAY IN MANITOWOC COUNTY. RUC SUGGESTS WINDS WILL REMAIN SOMEWHAT FAVORABLE THROUGH ABOUT 18Z THEN BACK ENOUGH SO THAT SNOW MOVES OFFSHORE. PARTLY SUNNY AND COLD ELSEWHERE. COMPACT SYSTEM OVER EASTERN NORTH DAKOTA LOOKS LIKE IT WANTS TO MOVE SOUTHEAST TOWARDS OUR FORECAST AREA ACCORDING TO SATELLITE PICTURES. BUT MODELS INSIST THAT BIG SORM MOVING THROUGH EASTERN UNITED STATES KEEPS IT FROM MOVING EAST...AND EASTERN WISCONSIN IS MORE OR LESS IN SUBSIDENCE AREA BETWEEN THE STORM SYSTEMS. SO EASTERN DAKOTA STORM SHOULD DIG MORE TO THE SOUTH AND WEAKEN. SOME LIGHT SNOW POSSIBLE IN THE WESTERN PART OF THE FORECAST AREA TONIGHT AND SUNDAY BUT NOTHING SIGIFICANT EXPECTED. CLOUDS WILL HAVE A LARGE EFFECT ON LOW TEMPERATURES TONIGHT. & .LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY NIGHT. TEMPERATURES WILL BE THE MAIN CONCERN ON SUNDAY NIGHT. 00Z GFS AND 00Z ECMWF HAD A SURFACE HIGH FORECAST TO MOVE FROM THE NORTHERN PLAINS TO IOWA DURING THE DAY. THIS SHOULD BRING DRIER AIR AND WEAK SURFACE FLOW TO THE AREA...ALLOWING TEMPERATURES TO FALL BELOW ZERO IN THE NORTH TO THE 10 TO 15 DEGREE RANGE ALONG THE LAKESHORE. THE NEXT CONCERN IS THE CHANCE FOR PRECIPITATION TUESDAY WITH A 500MB SHORT WAVE IN NORTHWEST FLOW THAT MODELS SHOWED PASSING THROUGH THE REGION AS A SURFACE LOW MOVED ACROSS ONTARIO. HAVE GONE WITH A CHANCE OF SNOW ONLY IN NORTHERN DOOR COUNTY AND A SLIGHT CHANCE OF RAIN AND SNOW FOR MOST OTHER LOCATIONS NORTHEAST OF A LINE FROM TOMAHAWK TO OSHKOSH. PRECIPITATION TYPE IS STILL IN QUESTION WITH WARM ADVECTION EARLY...AND THEN COLD ADVECTION IN THE NORTH LATER IN THE DAY. A WEAK 500MB RIDGE AND A SURFACE RIDGE SHOULD THEN KEEP THE AREA FREE OF PRECIPITATION THROUGH WEDNESDAY AS THEY PASS THROUGH WISCONSIN. PRECIPITATION CHANCES RETURN STARTING ON WEDNESDAY NIGHT AS A 500MB TROUGH APPROACHES FROM THE PLAINS ALONG WITH A SERIES OF SURFACE LOWS ALONG A TROUGH AXIS FROM HUDSON BAY TO MEXICO. POPS WERE INCREASED INTO THE CHANCE CATEGORY ON WEDNESDAY NIGHT BUT PRECIPITATION TYPE IS UNCERTAIN OVER MOST OF THE AREA AS SURFACE TEMPERATURES DROP DURING THE EVENING. THE FOX VALLEY EAST TO THE LAKE SHOULD BE WARM ENOUGH FOR RAIN DURING THE EVENING...BUT SUB-FREEZING TEMPERATURES ARE EXPECTED BY MORNING SO A MIX WAS MENTIONED FOR LATER IN THE NIGHT. && .AVIATION...LOCAL MVFR CIGS AND SNOW SHOWERS POSSIBLE AROUND MTW THROUGH 18Z TODAY...BUT VFR EXPECTED ELSEWHERE TODAY AND TONIGHT. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ RDM/MG wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 316 AM CST SAT MAR 8 2008 ..DISCUSSION...FORECAST FOCUS IS ON LAKE EFFECT SNOW SHOWERS THIS MORNING...THEN ON GENERALLY QUIET WEATHER THROUGH WEDNESDAY. IT APPEARS THAT HEAVY LAKE EFFECT SNOW SHOWERS ARE UNLIKELY TO OCCUR THIS MORNING FOR A VARIETY OF REASONS. RUC AND GFS SOUNDINGS INDICATE A LOW LEVEL INVERSION AT AROUND 1K FEET...AND ANOTHER INVERSION AROUND 4K FEET. THE COLUMN APPEARS TO BE QUITE DRY ABOVE 4K FEET WITH LITTLE OR NO OMEGA. ALSO...THE FETCH IS NOT OPTIMAL AND LAKE INDUCED MOISTURE IS VERY LIMITED. THERE IS NO ORGANIZED BANDS SHOWING ON RADAR AT THIS TIME...JUST MULTIPLE VERY WEAK BANDS GENERALLY NORTH OF CWA. THESE CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE MORNING HOURS...WITH ONLY WEAK UNORGANIZED SNOW BANDS AFFECTING THE AREAS CLOSE TO LAKE MICHIGAN. WITH A 25 TO 1 RATIO...I EXPECT AREAS NEAR LAKE MICHIGAN COULD SEE AN INCH OR 2 AT MOST THIS MORNING...AND ONLY SCATTERED VERY LIGHT SNOW SHOWERS THIS AFTERNOON. A VERY WEAK AREA OF LOW PRESSURE IS FORECAST TO DRIFT ACROSS SOUTHERN SECTIONS OF THE CWA TONIGHT AND SUNDAY. HOWEVER...THERE IS VERY LITTLE DYNAMICS AND QPF ASSOCIATED WITH THE SYSTEM. THERE MAY BE A BRIEF PERIOD OF ISENT LIFT BETWEEN 00Z AND 06Z THIS EVENING...BUT LITTLE ELSE TO RECOMMEND THE SYSTEM. I THINK SOME LIGHT SNOW AND FLURRIES WILL OCCUR...BUT WIDESPREAD MEASURABLE SNOW IS UNLIKELY AT THIS TIME. POPS WILL REMAIN LOW. QUIET WEATHER IS EXPECTED SUNDAY NIGHT THROUGH WEDNESDAY. THE COLUMN REMAINS QUITE DRY WITH NO DYNAMICS. MODELS ARE CONSISTENT WITH STRONG WARMING TREND BEGINING MONDAY...WITH TEMPERATURES TUESDAY AND WEDNESDAY ABOVE SEASONAL NORMALS. && .AVIATION...PREDOMINANT SINGLE LAKE EFFECT SNOW BAND IS PUSHING INLAND AS NE GRADIENT FLOW OVERCOMING WEAKER NNW FLOW ON WRN SIDE OF LK MI. SINGLE BAND IS EVOLVING INTO SHORTER MULITPLE BANDS...MAINLY FROM SHEBOYGAN NORTH. EXPECT VFR CIGS AND VSBYS WITH BRIEF MVFR CONDITIONS AS THE LIGHT SNOW BANDS MOVE ACROSS KMKE AND KENW THROUGH 18Z...THEN BANDS AND CLOUDS PUSH OUT OVER LAKE MICHIGAN. KMSN SHOULD SEE PREVAILING VFR CONDITIONS THROUGH THE PERIOD. && .MARINE...ALTERED GENERAL SMALL CRAFT ADVISORY TO A SMALL CRAFT FOR HAZARDOUS SEAS UNTIL 00Z SAT AS WINDS HAVE FALLEN BELOW CRITERIA...BUT WAVES TO REMAIN ABOVE CRITERIA AT 4 TO 6 FEET...MAINLY TOWARD OPEN WATER THEN SUBSIDE THROUGH THE AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM CST THIS AFTERNOON FOR LMZ643>646. && $$ SHORT/LONG TERM...35 AVIATION/MARINE...09 wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 950 AM EDT MON MAR 10 2008 .SYNOPSIS... HIGH PRESSURE OVER THE MID ATLANTIC AND SOUTHEAST STATES TODAY WILL DRIFT OFF THE COAST THIS EVENING. A WEAK DRY COLD FRONT WILL CROSS THE AREA TONIGHT. HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE GULF STATES TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 950 AM MONDAY... THIS AFTERNOON...WV IMAGERY AND RUC ANALYSIS SUGGEST SOME STRENGTHENING OF PJ THAT EXTENDS SW TO NE FROM THE TN VALLEY TO OFF THE MID ATLANTIC COAST...AIDING IN SOME ENHANCEMENT OF CIRRUS ACROSS THE REGION. THIS IN RESPONSE TO THE NORTHERN STREAM IMPULSE...DIVING SE THROUGH THE OHIO VALLEY...WHICH IS PROGGED TO MOVE THROUGH THE AREA OVERNIGHT. OTHERWISE...MOSTLY SKIES ARE EXPECTED THROUGH THE MAJORITY OF THE AFTERNOON...WITH AN INCREASE IN MID AND HIGH CLOUDS LATE IN THE AFTERNOON/EARLY EVENING IN ADVANCE OF THE SHORTWAVE TROUGH. WEAK LOW-LEVEL WAA WILL ENSUE THIS AFTERNOON AS LOW-LEVEL WIND PROFILE VEERS AROUND TO SW. THICKNESSES THIS MORNING VERIFIED AT 1320M THIS MORNING AT KGSO...VERY CLOSE TO THE NORMAL THICKNESS (1324M)FOR THIS DATE...ARE EXPECTED TO INCREASE TO AROUND 1335M. THIS WOULD YIELD A 5 TO 6 DEGREE INCREASE FROM SUNDAY`S HIGH TEMPERATURES...SUPPORTING HIGHS IN THE UPPER 50S TO LOWER 60S. TONIGHT... ALTHOUGH THERE WILL BE UPPER LEVEL LIFT IN THE FORM OF DPVA...AND SFC LIFT ASSOC/W A WEAK COLD FRONTAL PASSAGE (PRIMARILY BETWEEN 00-09Z TONIGHT)...THE LIFT WILL BE RATHER WEAK BECAUSE THE UPPER LEVEL WAVE WILL BE DE-AMPLIFYING AND THE SFC BOUNDARY ASSOC/W THE WEAK LOW MOVING EAST THROUGH THE DELMARVA WILL BRING ONLY WEAK/SHALLOW LOW LEVEL CONVERGENCE. ADDITIONALLY...WITH WESTERLY FLOW GENERALLY THROUGHOUT MOST OF THE COLUMN...THE ATMOSPHERE WILL BE RATHER DRY TONIGHT...WITH FCST PWAT VALUES OF 0.50" OR LESS. BOTH THE GFS/NAM KEEP ANY LIGHT MEASURABLE PRECIP ASSOC/W THIS SYSTEM WELL NORTH OF CENTRAL NC...AND ALONG THE FAVORABLE UPSLOPE AREAS ALONG/WEST OF THE RIDGELINE IN WV/VA. THEREFORE...ALTHOUGH WE WILL LIKELY SEE CLOUDY SKIES AT TIMES...WILL KEEP THE FORECAST DRY DUE TO THE ANEMIC AMOUNT OF MOISTURE/LIFT PROGGED. LOW TEMPS MAY BE A BIT TRICKY DEPENDING ON THE TIMING/EXTENT OF ANY CLOUD COVER...BUT A RANGE OF 35-41F SUGGESTED BY THE LATEST MOS GUIDANCE APPEARS REASONABLE. -VINCENT && .SHORT TERM /TUESDAY THROUGH THURSDAY/... AS OF 245 AM MONDAY... TUESDAY AND TUESDAY NIGHT: WNW/NW FLOW ALOFT WILL GENERALLY BE PRESENT IN THE UPPER LEVELS BEHIND THE DEPARTING UPPER LEVEL WAVE DURING THE DAY TUESDAY. THERE MAY BE SOME VERY WEAK SFC AND UPPER LEVEL TROUGHING PERSISTING OVER THE CAROLINAS DURING THE DAY (LOOKS LIKE A PIECE OF ENERGY FROM THE UPPER LEVEL WAVE PASSING THROUGH THE AREA TONIGHT BREAKS OFF AND LINGERS)...AND THE NAM IS A BIT MORE AGGRESSIVE IN SHOWING THIS THAN THE GFS. THE GFS PROGS PWAT VALUES AROUND 0.20" ON TUESDAY...WHILE THE NAME IS OVER TWICE AS MOIST WITH PWAT VALUES IN THE 0.45" RANGE. THE ONLY REAL DIFFERENCE THIS COULD MAKE IN THE FORECAST IS WITH TEMPS AND WHETHER OR NOT DIURNAL CU WILL DEVELOP DURING THE AFTERNOON HOURS TUE. W/REGARDS TO TEMPS...THE NAM FCST SOUNDINGS ARE SHOWING DEEP MIXING ON TUE...UP TO 750MB...WHILE THE GFS FCST SOUNDINGS ARE QUITE A BIT SHALLOWER...MIXING UP TO ONLY 850-900MB. THICKNESSES ARE PROGGED TO RANGE FROM 1315-1340 METERS 12Z TUE... INCREASING TO 1330-1350 METERS DURING THE AFTERNOON. THE GFS THICKNESSES ARE COLDER THAN THE NAM BY 5-15 METERS. LOCAL TEMP RESEARCH SUGGEST A RANGE FROM THE UPPER 50S TO LOWER 60S ON TUE BASED ON THESE THICKNESSES. THE 850MB TEMPS OFF THE GFS/NAM VARY BY ABOUT 4C TUE AFTERNOON...WITH THE GFS BEING COLDER THAN THE NAM...AND USING THE DRY-ADIABATIC METHOD...THIS RESULTS IN A 5-8F DIFFERENCE IN HIGH TEMPS (UPPER 50S VERSUS LOWER/MID 60S). MOS GUIDANCE IS INDICATING HIGH TEMPS IN THE LOWER/MID 60S ON TUE. BEARING ALL OF THIS IN MIND...WILL TRY TO BLEND THE RESULTS FROM THESE DIFFERENT METHODS AND MOS GUIDANCE...AND FORECAST A RANGE OF 61-64F ACROSS THE AREA. OVERNIGHT...WITH CLEAR SKIES AND A RELATIVELY DRY AIRMASS IN PLACE...RADIATIONAL COOLING SHOULD BE CLOSE TO OPTIMAL...ALTHOUGH THE FCST MSLP GRADIENT SUGGESTS THERE MAY BE VERY LIGHT WINDS IN SOME LOCATIONS. LOW TEMPS IN THE MID 30S TO LOWER 40S LOOK REASONABLE...AND THIS IS WHAT MOS GUIDANCE IS SUGGESTING. WEDNESDAY AND WEDNESDAY NIGHT: A WEAK SOUTHERN STREAM TROUGH IS PROGGED TO TRANSLATE EAST ALONG THE GULF COAST ON WEDNESDAY...WHILE AN UPPER LEVEL TROUGH OVER NEW ENGLAND IS PROGGED TO LIFT ENE TOWARD NOVA SCOTIA. NORTH CAROLINA WILL REMAIN IN-BETWEEN THESE UPPER LEVEL SYSTEMS...AND BENIGN WEATHER IS EXPECTED TO CONTINUE DURING THE DAY WED...WITH MOSTLY SUNNY SKIES. ADDITIONALLY...WEAK SHORTWAVE RIDGING ALOFT IS PROGGED TO APPROACH THE STATE FROM THE WEST BY WED EVENING. THICKNESSES OFF THE GFS/NAM ON WED ARE VERY SIMILAR TO TUE...AND FCST SOUNDINGS OFF THE GFS/NAM ARE MUCH MORE IN-LINE WITH EACH OTHER THAN THEY ARE FOR TUE...BOTH SHOWING MIXING UP TO 850MB WITH 2-3C TEMPS AT THAT LEVEL. BASED ON THE THICKNESSES AND H85 TEMPS...WILL FORECAST MAX TEMPS A FEW DEGREES WARMER THAN TUE...RANGING FROM 63-67F...SLIGHTLY LOWER THAN MOS GUIDANCE IN MOST LOCATIONS. GOOD RADIATIONAL COOLING NIGHT APPEARS ON TAP WED NIGHT...AND WILL FORECAST LOW TEMPS RANGING FROM THE MID 30S TO LOWER 40S (COOLEST TEMPS IN RURAL AREAS). THURSDAY: WEAK SHORTWAVE RIDGING ALOFT IS PROGGED BY THE 00Z GFS/12Z ECMWF (NEWEST ECMWF NOT IN YET) TO CROSS OVER THE STATE ON THU. THE ECMWF SHOWS A NARROW SFC RIDGE AXIS (WEAK/DRY CAD SIGNATURE) IN THE LEE OF THE SOUTHERN APPALACHIANS THU MORNING...ASSOC/W 1025MB HIGH PRESSURE IN QUEBEC. THE GFS IS WEAKER WITH THE SFC HIGH IN CANADA...AND SHOWS NO HINT OF A SFC RIDGE AXIS IN THE LEE OF THE MOUNTAINS THU MORNING. THIS DIFFERENCE COULD HAVE AN IMPACT ON HIGH TEMPS THU...ALTHOUGH EVEN IF THE 12Z 03/09 ECMWF IS ON TO SOMETHING...NO DIABATIC ENHANCEMENT OF THE POTENTIAL WEDGE WOULD OCCUR...AND A VERY WEAK/DRY CAD SIGNAL WOULD NOT MAKE TOO MUCH OF A DIFFERENCE IN MAX TEMPS OVER CENTRAL NC ANYWAYS. BASED ON THE OVERALL SYNOPTIC PATTERN...MOSTLY SUNNY SKIES ARE EXPECTED ON THU (EXCEPT PERHAPS A FEW MID/UPPER LEVEL CLOUDS MOVING INTO THE AREA FROM UPSTREAM). HIGH TEMPS ON THU LOOK TO BE A FEW DEGREES WARMER THAN ON WED GIVEN THICKNESSES IN THE 1340-1360 METER RANGE...AND WILL FORECAST ABOVE NORMAL HIGH TEMPS RANGING FROM 65-69F ACROSS THE AREA. -VINCENT && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... AS OF 400 AM MONDAY... A COUPLE OF WAVES IN RAPID SUCCESSION WITHIN FAST WESTERLY FLOW APPROACH LATE IN THE WEEK AND APPEAR TO ORIGINATE IN A STRONG PERTURBATION OVER THE NORTH PAC NOW BETWEEN 160-180W. THOUGH BOTH GFS AND ECMWF SHOW GENERALLY THE SAME TWO-WAVE PATTERN... CONFIDENCE REMAINS LOW FOR DETAILS ON THE TIMING AND IMPACT OF THESE DISTURBANCES ON SENSIBLE WEATHER OVER CENTRAL NC THU NIGHT THROUGH SAT NIGHT. FORECASTS WILL SHOW AN INCREASE IN CLOUDINESS THU NIGHT AND VARIABLY TO MOSTLY CLOUDY SKIES FRI THROUGH SAT THEN DECREASING CLOUDINESS SAT NIGHT INTO SUN. RAIN CHANCES WILL BE MAINLY IN THE 20-30 PERCENT RANGE FRI-SAT. TEMPERATURES SHOULD AVERAGE CLOSE TO NORMAL WITH A SOMEWHAT NARROWED DIURNAL RANGE BECAUSE OF EXPECTED CLOUDINESS. -RFG && .AVIATION /11Z MONDAY THROUGH FRIDAY/... AS OF 950 AM MONDAY... CONFLUENT WESTERLY FLOW ALOFT AND A COUPLE OF DRY COLD FRONTS LEADING DRY CONTINENTAL AIR THROUGH CENTRAL NC SHOULD MAINTAIN VFR CONDITIONS THROUGH THU NIGHT. A STRONGER SOUTHERN STREAM WAVE AND ASSOCIATED TRANSIENT LOW PRESSURE SYSTEM MAY LOWER CIGS AND VSBY TO MVFR OR IFR WITH AREAS OF RAIN FRI. -RFG && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CBL/VINCENT NEAR TERM...VINCENT SHORT TERM...VINCENT LONG TERM...RFG AVIATION...RFG nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 415 PM EDT MON MAR 10 2008 .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW INTO THE WESTERN GREAT LAKES BTWN A TROF OVER ERN CANADA AND A RIDGE OVER WRN NOAM. THE MAIN UPSTREAM FEATURE WAS...A SHORTWAVE TROUGH MOVING FROM NORTHERN ALBERTA INTO SASKATCHEWAN. AT THE SFC...WRLY FLOW WAS INCREASING BTWN HIGH PRES OVER IA/KS/MO AND A TROUGH/FRONT OVER NRN ONTARIO. WITH THE VERY DRY AIRMASS IN PLACE...THE WAA PATTERN INTO UPPER MI WAS ONLY BRINGING AN INCREASE IN HIGH CLOUDS. .SHORT TERM (TONIGHT AND TUESDAY)... ALTHOUGH RADIATIONAL COOLING MAY ALLOW TEMPS TO FALL OFF THIS EVENING...INCREASING WINDS AND HIGH CLOUDS OVERNIGHT MAY RESULT IN STEADY OR SLOWLY RISING TEMPS FROM MIN VALUES IN THE UPPER TEENS. DOWNSLOPE WSW WINDS WILL ALSO KEEP TEMPS UP OVER PORTIONS OF WEST AND N CNTRL UPPER MI. TUE...MODERATE TO STRONG 700-500 MB QVECTOR CONV ALONG WITH FAIRLY STEEP 700-500 MB LAPSE RATES(AROUND 7 TO 7.5 C/KM) SHOULD BE ENOUGH TO SUPPORT SOME LIGHT SNOW FROM NRN LAKE SUPERIOR INTO THE NE CWA IN SPITE OF THE ANTECEDENT DRY AIR. SO...THE FCST LEANED A BIT MORE TOWARD THE GFS AND CANADIAN REGIONAL GEM WITH LIKELY POPS NE AND CHANCE N CNTRL COMPARED TO THE NAM WHICH DOES NOT PRODUCE ANY PCPN OVER UPPER MI. ANY PCPN SHOULD TAPER OFF IN THE AFTERNOON. MODEL SOUNDINGS AND LOW LEVEL WET-BULB ZERO VALUES WOULD KEEP PCPN AS SNOW. QPF VALUES SUGGEST ANY SNOWFALL WILL BE LESS THAN INCH. .LONG TERM (TUESDAY NIGHT THROUGH NEXT MONDAY)... NW WINDS ON BACK SIDE OF LOW ALONG WITH H85 TEMPS NEAR -10C GOOD ENOUGH FOR CHANCE POPS EARLY TUE NIGHT OVR FAR EAST CWA. OTHERWISE...EXPECT CLEARING SKIES WITH TEMPORARY RIDGING. PWAT MIN MOVING THROUGH SUGGESTS SOME RADIATIONAL COOLING CAN TAKE PLACE. WENT BLO GUIDANCE FOR MIN TEMPS. INCREASING CLOUDS BY MIDDAY WED THEN MIXED PRECIPITATION STILL ON TRACK FOR LATE WEDNESDAY INTO WEDNESDAY EVENING. GFS/ECMWF/CANADIAN IN VERY GOOD AGREEMENT IN TRACKING A NORTHERN STREAM WAVE (A PIECE OF ENERGY EMERGING FM THE STRONGER SHORTWAVE NOW OFFSHORE OF BRITISH COLUMBIA) AND SFC LOW JUST NORTH OF LK SUPERIOR ON THU. DESPITE FACT THAT GFS SHOWS H3 JET STREAKING INTO GREAT LAKES ON WED NIGHT AND THE ECMWF NOT HAVING ANY SUCH FEATURE...MAJORITY OF PCPN THAT OCCURS WED NIGHT IS TIED TO LIFTING ALONG ADVANCING SFC TROUGH AND ISENTROPIC LIFT ON THE 280-290K SFCS. GFS/ECMWF SHOW MUCH BETTER AGREEMENT ON THESE FEATURES ALONG WITH RESULTING QPF. HAVE INCREASED POPS TO LIKELY. PTYPE ALSO SEEMING TO COME INTO SOME AGREEMENT. DEPENDING ON HOW QUICKLY PCPN ARRIVES ON WED POTENTIAL FOR RAIN/SNOW MIX EXISTS INTO EARLY WED EVENING DUE TO RESIDUAL WARM AIR NEAR SFC. 1000-850MB THICKNESSES AND 2M TEMPS FM ECMWF/GFS SUGGEST ANY MIXED RAIN/SNOW WOULD CHANGE TO SNOW BY 06Z THU. COULD SEE UP TO 2 INCHES OF SNOW WITH THE SYSTEM ON WED NIGHT. IN WAKE OF THE SFC TROUGH...DRY AIR SHOULD LIMIT PCPN CHANCES THU. ECMWF/GFS/CANADIAN ALL SHOW A MINIMUM IN QPF IN THE 12 HR PERIOD ENDING AT 00Z FRI. PACIFIC AIR PUSHING IN BEHIND THE TROUGH ALLOWS TEMPS TO WARM INTO THE 30S. SO...IF ANY PCPN DOES OCCUR IT WOULD LIKELY BE IN FORM OF A RAIN/SNOW MIX OR STRICTLY RAIN. PREFERRED LESS AMPLIFIED/WARMER ECMWF/CANADIAN COMPARED TO GFS INTO THE WEEKEND. 12Z GFS IS COMING AROUND TO LESS TROUGHING OVR THE WESTERN GREAT LAKES. H9-H85 TEMPS LOOK MARGINAL FOR LK EFFECT BUT WITH A NORTH WIND AND WEAK CYCLONIC FLOW LINGERING NEED TO KEEP SOME POPS NEAR LAKE SUPERIOR FRI INTO SAT. LK EFFECT ENDS BY SUNDAY AS WINDS BECOME SE WITH SFC RIDGE MOVING ACROSS THE AREA. GFS/ECMWF CONSISTENT ON DEVELOPING SIGNIFICANT STORM SYSTEM OVR NATIONS MID SECTION BY NEXT MONDAY. ECMWF HAS LATCHED ONTO THIS SOLUTION AND BEEN FAIRLY CONSISTENT WITH IT FOR THE LAST FEW DAYS. DETAILS SHOULD BE TAKEN WITH GRAIN OF SALT AT THIS POINT AS THE SHORTWAVES THAT ARE PROGGED TO MORPH INTO THIS LARGE SYSTEM ARE STILL OUT IN THE PACIFIC...NEAR THE GULF OF ALASKA AND EXITING JAPAN. WILL NEED TO WAIT TIL THE UPCOMING WEEKEND WHEN ENERGY REACHES THE WEST COAST BEFORE IT BECOMES SAMPLED BY RAOB NETWORK. IT IS PRETTY INTERESTING THOUGH HOW CONSISTENT THE MODELS HAVE BEEN WITH A SYSTEM THIS FAR OUT IN TIME. STRONG NEGATIVELY TILTED SYSTEMS EJECTING OUT OF THE SOUTHWEST CONUS CAN END UP SLOWER THAN PROGGED SO DECIDED TO KEEP PCPN OUT OF CWA ON SUN NIGHT. FOR NOW...HAVE CHANCE POPS OVER ALL AREAS BY LATE ON DAY 7. TRACK OF STORM SUGGESTS SNOW FOR PTYPE BUT A FARTHER WEST TRACK WOULD RESULT IN LIQUID PCPN. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... EXPECT VFR CONDITIONS AT BOTH TAF SITES THROUGH TONIGHT AS HIGH PRES RIDGE DOMINATES THE REGION. LOW LEVEL WIND SHEAR SHOULD DEVELOP AS A WRLY LOW LEVEL JET DEVELOPS BETWEEN THE DEPARTING RIDGE AND LOW PRES MOVING INTO NRN ONTARIO. WAA AHEAD OF THE LOW ILL LEAD TO THE CONTINUED LOWERING OF A MID-LVL CLOUD DECK FROM THIS EVENING INTO THE OVERNIGHT HOURS. MVFR CIGS AREA EXPECTED AS A COLD FRONT MOVES INTO UPPER MI TUE MORNING. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... SOUTHWEST WINDS TO 30 KT ARE EXPECTED OVER PORTIONS PORTIONS OF LAKE SUPERIOR TONIGHT AHEAD OF THE NEXT APPROACHING LOW PRES TROUGH FROM CANADA. AS THE TROUGH PASSES ON TUESDAY WINDS WILL SHIFT NORTHWEST TO 25 KT OVER THE ERN HALF OF THE LAKE TUESDAY AFTERNOON AND EVENING. WINDS DIE OFF BRIEFLY LATE TUESDAY NIGHT AND EARLY WEDNESDAY BUT THEN INCREASE AGAIN TO 30 KT FROM THE SOUTH-SOUTHEAST WED EVENING AHEAD OF YET ANOTHER CLIPPER LOW WED NIGHT. WINDS SHIFT WEST-NORTHWEST BY FRIDAY BEHIND THE TROUGH PASSAGE AND MAY APPROACH 30 KT OVER THE FAR ERN PORTION OF THE LAKE. DUE TO EXTENSIVE ICE COVERAGE OVER THE WEST HALF OF THE LAKE AND WARMING TEMPERATURES...FREEZING SPRAY WILL NOT BE MUCH OF A FACTOR. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION/MARINE...JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 340 PM EDT MON MAR 10 2008 .SHORT TERM...THIS AFTERNOON AND TONIGHT THE QUALITY OF MOISTURE HAS REMAINED POOR...KEEPING THE SNOW ACTIVITY TO PREDOMINATELY FLURRIES. LATEST TAMDAR SOUNDINGS DEPICT A SATURATED ENVIRONMENT LIMITED TO THE 900-700MB LAYER. THIS AFTERNOONS WATER VAPOR IMAGERY/RUC GUIDANCE EXITS THE SHORTWAVE RESPONSIBLE FOR THE CLOUDS/FLURRIES MOMENTARILY. WILL CARRY NO HYDROMETEORS THIS EVENING AND OVERNIGHT WITH SUBSIDENCE/ANTICYCLONIC VORTICITY ADVECTION AND LOSS OF ANY DIURNALLY ENHANCED LAPSE RATES. TEMPERATURES SHOULD DIP RATHER QUICKLY THIS EVENING AS WINDS REMAIN SUBDUED AND CLOUDS SCATTER QUICKLY. MAINLY GONE A DEGREE OR TWO BELOW GUIDANCE GIVEN FAVORABLE RADIATING CONDITIONS...AROUND 20 FOR MOST AREAS. SHOULD NOT GET QUITE AS COLD TONIGHT SINCE RETURN FLOW WILL DEVELOP ALLOWING FOR SOME WARM AIR ADVECTION. && .LONG TERM...TUESDAY THROUGH MONDAY THE 12Z MODEL SUITE ARE IN GOOD AGREEMENT WITH RESPECT TO A NORTHERN STREAM WAVE EXPECTED TO MOVE ACROSS THE STATE FROM CENTRAL CANADA TUESDAY AFTERNOON AND EVENING. THE CURRENT WATER VAPOR LOOP ALREADY INDICATES A STRONG UPPER JET OVER WESTERN CANADA. THIS JET IS FORECAST TO DIVE INTO THE WESTERN GREAT LAKES REGION TUESDAY AFTERNOON...STRENGTHENING TO 110 KTS. UPPER DIVERGENCE ASSOCIATED WITH THE LEFT EXIT REGION OF THIS JET WILL BE FOCUSED ACROSS SOUTHERN MICHIGAN BY 00Z WED. THE UPPER JET WILL ALSO ALLOW THE MID LEVEL WAVE TO AMPLIFY AS IT CROSSES THE STATE. THE ASSOCIATED SURFACE LOW IS EXPECTED TO PASS NORTH OF THE STATE...WHILE A SURFACE TROUGH AXIS SWINGS THROUGH SE MI BETWEEN 00Z AND 03Z WED. THIS SYSTEM IS EXPECTED TO HAVE GOOD DYNAMICS...WITH A STRONG YET BRIEF SHOT OF DCVA AND UPPER DIVERGENCE. MODEL SOUNDINGS SHOW LACK OF DEEP MOISTURE TO BE THE MAIN LIMITING FACTOR FOR PRECIP. ALL MODEL SOLUTIONS DO HOWEVER SHOW A NARROW RIBBON HIGHER 850-700MB THETA E AIR ADVECTING AHEAD OF THE SURFACE TROUGH. THIS COMBINED WITH THE DYNAMICS WILL WARRANT A LOW CHANCE OF PRECIP BETWEEN THE 21Z TUE AND 03Z WED TIME FRAME. WITH SURFACE TEMPS FORECAST TO RISE INTO THE UPPER 30S/NEAR 40 TUES AFTERNOON...THE BOUNDARY LAYER LOOKS TO BE WARM ENOUGH TO SUPPORT A MIX OF RAIN AND SNOW. MID LEVEL HEIGHTS WILL QUICKLY REBOUND ACROSS THE STATE ON WEDNESDAY IN THE WAKE OF TUESDAY EVENINGS WAVE. SKIES SHOULD ALSO CLEAR OUT BY WEDNESDAY MORNING AS SURFACE HIGH PRESSURE BUILDS ACROSS THE REGION. A BACK DOOR COLD FRONT...ASSOCIATED WITH THE DEPARTING LOW IS FORECAST TO SINK S-SE ACROSS LAKE HURON LATE TUES NIGHT INTO WEDNESDAY...CAUSING 850MB TEMPS TO DROP TO -8 TO -10C OVER THE THUMB REGION BY WED MORNING. THUS...HAVE BACKED OFF WED HIGHS A BIT...CARRYING MAX TEMPS ONLY IN THE LOWER 30S IN THE THUMB TO NEAR 40 WEST OF THE I-75 CORRIDOR. BY WEDNESDAY EVENING THE NEXT WAVE IS ALREADY FORECAST TO BE ADVANCING INTO THE WESTERN GREAT LAKES REGION IN THE VERY PROGRESSIVE NORTHERN STREAM. WHILE THE MAIN SURFACE LOW IS FORECAST TO PASS NORTH OF THE STATE...MODELS DO SHOW AN OCCLUDED FRONT MOVING ACROSS SOUTHERN MI EARLY THURS MORNING. STRONG LOW TO MID LEVEL THETA E ADVECTION LATE WED NIGHT AND THURSDAY MORNING WILL AGAIN WARRANT A CHANCE OF PRECIP. MODELS ARE NOT OVERLY ROBUST WITH THE QPF. HOWEVER GIVEN THE MAGNITUDE OF ISENTROPIC ASCENT...WILL CONTINUE WITH HIGH CHANCE POPS OVERNIGHT WED THROUGH THURS MORNING. A WARMING BOUNDARY LAYER SHOULD SUPPORT MAINLY RAIN AROUND THE DETROIT AREA. LOWER WET BULB ZERO HEIGHTS FARTHER NORTH SHOULD HOWEVER SUPPORT A RAIN/SNOW MIX...POSSIBLY EVEN SOME SLEET. WITH THE FLOW ALOFT TRANSITIONING TO MORE ZONAL ACROSS THE CONUS BY LATE IN THE WEEK...THE AMOUNT OF COLD AIR ADVECTION IS NOT OVERLY IMPRESSIVE IN THE WAKE OF THURSDAYS SYSTEM. THE CURRENT FORECAST HAS HIGHS IN THE LOW TO MID 40S THURS AND FRI WHICH STILL LOOKS REASONABLE. THE NEXT SYSTEM TO MONITOR IS A WAVE IN THE SOUTHERN STREAM FORECAST TO MOVE ACROSS THE OHIO VALLEY ON SATURDAY. THE GFS HAS BEEN TRENDING MORE AMPLIFIED WITH THIS WAVE...AS WELL AS WITH MID LEVEL FGEN OVER THE SOUTHERN GREAT LAKES. THIS MORE AMPLIFIED SOLUTION SOLUTION WOULD BRING COLDER AIR INTO THE STATE ON SATURDAY ALONG WITH THE POTENTIAL FOR ACCUMULATING SNOWFALL ACROSS THE METRO DETROIT AREA AND POINTS SOUTH. THE 12Z ECMWF ALONG WITH SEVERAL GFS ENSEMBLE MEMBERS KEEP THE BULK OF QPF SOUTH OF THE STATE. SO AT THIS TIME A CHANCE OF SNOW ACROSS THE SOUTHERN 1/3RD OF THE CWA SEEMS REASONABLE. && .MARINE... SURFACE LOW PRESSURE IS FORECAST TO PASS JUST NORTH OF LAKE HURON LATE TUESDAY AFTERNOON AND EVENING...SENDING A COLD FRONT ACROSS THE LAKE AROUND 00Z. SOUTHWESTERLY WINDS WILL INCREASE ACROSS THE LAKES TUES AFTERNOON. MODEL SOUNDINGS ONLY SHOW LIMITED MIXING HEIGHTS OVER LAKE HURON. THE SHALLOW INSTABILITY HOWEVER SHOULD BE ENOUGH TO PROVIDE FREQUENT GUSTS OF 25 TO 30 KNOTS TUES AFTERNOON. MIXING HEIGHTS WILL INCREASE OVER THE LAKES WED NIGHT IN THE WAKE OF THE SURFACE FRONT. THE GRADIENT WILL HOWEVER BEGIN TO WEAKEN...THUS WIND GUSTS SHOULD REMAIN AROUND 25 KNOTS ACROSS THE OPEN WATERS OF LAKE HURON. HIGH PRESSURE WILL BUILD INTO THE REGION BY WED AFTERNOON...ALLOWING THE WINDS TO BECOME LIGHT AND VARIABLE. && .PREV DISCUSSION...ISSUED 144 PM EDT MON MAR 10 2008 AVIATION... OUTSIDE OF SCATTERED SNOW SHOWERS THIS AFTERNOON AT KDET/KDTW AND A TEMPORARY MVFR DECK AT KFNT...TRANQUIL CONDITIONS ARE EXPECTED AS SURFACE HIGH PRESSURE BUILDS INTO THE REGION. LIGHT AND VARIABLE SURFACE WINDS WILL SLOWLY TREND WESTERLY THIS EVENING AS RETURN FLOW ARRIVES. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... BRISK WIND ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS FROM PORT AUSTIN TO HARBOR BEACH...FROM 8 AM TUESDAY TO 8 PM TUESDAY. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...CB LONG TERM....SC MARINE.......SC AVIATION.....CB YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi