AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 630 AM EST SAT FEB 4 2006 .AVIATION... DEEPENING SFC LOW PRESSURE WAS LOCATED OVER SERN KENTUCKY AT 11Z THIS MORNING. THIS IS ON TARGET WITH PREVIOUS 00Z GFS MODEL RUN AND CURRENT 06Z GFS MODEL RUN. WILL USE A BLEND OF THE LATEST RUC AND 00Z/06Z GFS MODEL RUNS FOR THIS TAF PACKAGE. SFC LOW IS FCST TO MOVE TO A POSITION OVER SE OHIO BY 18Z... CNTRL LAKE ERIE BY 00Z...THEN OVER SRN ONTARIO BY 12Z. LARGE SCALE ASCENT ASSOCD WITH LEFT EXIT REGION OF UPR LVL JET...ALONG WITH DEVELOPING MID LVL DEFORMATION ASSOCD WITH 700 MB LOW...WILL PRODUCE THE HEAVIEST SNOW AT KFWA THIS AFTN. SNOW WILL NOT BE AS INTENSE AT KSBN AS THIS TAF SITE WILL REMAIN ON THE WRN PERIPHERY OF GREATEST UPWARD VERTICAL MOTION. EITHER WAY...CIGS AND VSBYS WILL DETERIORATE THROUGH THIS AFTN INTO THE IFR/LIFR CATEGORIES. FOR TONIGHT...SNOW WILL CONTINUE TO WRAP AROUND AFOREMENTIONED LOW...WITH LAKE ENHANCEMENT ADDING MOISTURE TO THE SYNOPTIC SCALE SYSTEM. IN ADDITION...A STRONG PRESSURE GRADIENT WILL PRODUCE SUSTAINED NORTHWEST WINDS AROUND 20 KNOTS WITH GUSTS AROUND 30 KNOTS. THE SNOW AND WIND WILL CAUSE CONSIDERABLE BLOWING OF SNOW...SO HAVE INCLUDED THIS IN THE TAFS AFTER 00Z. CIGS/VSBYS WILL REMAIN IN IFR CATEGORY. && .PREV DISCUSSION... SHORT TERM... TODAY AND TONIGHT CONCERNS ARE MANY AND REVOLVE AROUND UPGRADE OF CURRENT WATCH AND WESTWARD EXTENT OF ACCUMULATING SNOW...AS WELL AS POSSIBLE LAKE ENHANCEMENT LATE THIS AFTERNOON AND TONIGHT. WATER VAPOR IMAGERY EARLY THIS MORNING VERY IMPRESSIVE WITH NUMEROUS SHORTWAVES CARVING OUT A FULL LATITUDE TROUGH ACROSS THE CENTRAL CONUS. QUICKLY EVOLVING BAROCLINIC LEAF SIGNATURE ON SATELLITE INDICATIVE OF A RAPIDLY DEEPENING MID LATITUDE CYCLONE. EVERY SINGLE RUN OF THE GFS SINCE THE 00Z/03 ITERATION HAS TRENDED STEADILY WEST WITH SURFACE AND MID LEVEL FEATURES. HAND SURFACE ANALYSIS AND 3 HOUR PRESSURE FALLS WOULD SUGGEST A TRACK ALONG THE WESTERN EDGE OF THE GUIDANCE ENVELOPE. DYNAMIC NATURE OF THE EVOLVING TROUGH AND STEADILY INCREASING LOW LEVEL BAROCLINICITY ACROSS THE OHIO VALLEY WOULD ALSO SUGGEST LEANING TOWARDS THE DEEPER SOLUTIONS...THE 00Z GEM AND GFS WITH A HIGH 970S MB LOW JUST WEST OF TORONTO AT 12Z SUN. EVERYTHING IS COMING TOGETHER FOR A MAJOR WINTER STORM IN THE OHIO VALLEY AND GREAT LAKES. REGIONAL RADAR IMAGERY SHOWING INTENSE MESOSCALE BANDING STRUCTURE TAKING SHAPE OVER SOUTHEAST INDIANA EARLY THIS MORNING. FOLLOWING THE LEAD OF THE MORE CONSISTENT GFS SOLUTION...H7 LOW WILL QUICKLY CLOSE OFF AND DEEPEN TODAY AS IT MOVES ALONG A TRACK FROM NEAR FINDLAY TO SANDUSKY OHIO THIS AFTERNOON. THIS WILL PLACE NW OHIO AND EXTREME EASTERN INDIANA IN THE FAVORED AREA FOR HEAVY SNOW JUST LEFT OF THE H7 LOW TRACK. GFS FORECAST DEFORMATION FIELDS SUPPORT THE OLD RULE OF THUMB WITH THE H7 AXIS OF DILATATION PASSING OVER OUR EASTERN ZONES. EXPECT MID LEVEL TROUGH AXIS TO TAKE ON A SLIGHTLY NEGATIVE TILT BEFORE CLOSING OFF FULLY TONIGHT. BELIEVE THIS WILL HELP PULL MORE SIGNIFICANT PRECIP WEST INTO OUR CENTRAL ZONES AS WELL. TONIGHT AS SYSTEM CLOSES OFF AND CONTINUES TO RAPIDLY DEEPEN A SECONDARY DEFORMATION AXIS WILL LIKELY FORM FROM OUR NW COUNTIES ACROSS THE NORTH CENTRAL AND EASTERN CWA. DEEP CYCLONIC FLOW WILL PULL IN MARGINALLY COLD AIR FOR LAKE ENHANCEMENT BY LATE AFTERNOON THROUGH TONIGHT. THIS WILL LIKELY HELP TO PRODUCE HIGHER SNOWFALL TOTALS SE OF LAKE MICHIGAN THAN WOULD OTHERWISE BE EXPECTED FROM SYNOPTIC SCALE SYSTEM. WINDS WILL INCREASE LATE THIS AFTERNOON THROUGH TONIGHT WITH GUSTS TO AROUND 35 MPH TONIGHT. INITIALLY WARM BOUNDARY LAYER TEMPS WILL CREATE A WET SNOWPACK TODAY...BUT COOLING TEMPS TONIGHT COUPLED WITH STRENGTHENING WINDS WILL ALLOW CONSIDERABLE BLOWING/DRIFTING TO DEVELOP. BREAKING IT DOWN...WILL BE UPGRADING THE ENTIRE WATCH TO A WINTER STORM WARNING. PREVIOUS WATCH HIGHLIGHTED EASTERN HALF OF THE WATCH AREA FOR HEAVIER SNOW ACCUMS. PROBLEM HERE IS BOUNDARY LAYER TEMPS WILL LIKELY BE WARM ENOUGH FOR RAIN AT THE START...THEN SLOWLY COOLING ENOUGH TO ALLOW SNOW TO BEGIN TO ACCUMULATE. FARTHER WEST IN THE WATCH WHILE QPF WILL BE LOWER PRECIP WILL GO ALL SNOW EARLIER. HAVE DECIDED TO JUST GO WITH 4 TO 8 INCHES TOTAL ACROSS THE ENTIRE WARNING AREA. WEST OF THE WARNING WILL HOIST A SNOW AND BLOWING SNOW ADVISORY ACROSS THE CENTRAL ZONES. FINALLY...WILL ALSO HOIST A SNOW AND BLOWING SNOW ADVISORY FOR THE NW ZONES. THIS ADVISORY WILL HAVE A LATER START TIME...THIS AFTERNOON...AS BEST LAKE ENHANCEMENT DOES NOT SET UP UNTIL VERY LATE THIS AFTERNOON OR THIS EVENING. SNOW TOTALS IN THE ADVISORY AREA WILL BE 3 TO 5 ACROSS CENTRAL ZONES...WITH 4 TO 6 IN THE NW AND NORTH CENTRAL ZONES IN FAVORED LAKE ENHANCEMENT AND SECONDARY DEFORMATION AXIS AREAS. THANKS TO GRR...DTX...CLE...ILN...IND AND HPC FOR THE EXTENSIVE COLLABORATION ON HEADLINES AND SNOW AMOUNTS. LONG TERM... SUNDAY THROUGH FRIDAY. WITH ITS BETTER RUN TO RUN CONTINUITY...HAVE FOLLOWED THE 00Z GFS IN THE FIRST PART OF THE EXTENDED PERIOD. A DEEP SFC LOW IS FCST TO BE OVER SRN ONTARIO BY SUNDAY MORNING. GIVEN THE DEEPENING NATURE OF THE SYSTEM...ALONG WITH BROAD CYCLONIC FLOW WRAPPING AROUND IT...AM INCLINE TO CONTINUE WITH LIKELY POPS ACRS THE NORTHEAST CWFA AS SYSTEM MAY BE SLOW TO DEPART TO THE NORTHEAST. IN ADDITION...LONG FETCH OVER LAKE MICHIGAN...COMBINED WITH DELTA T/S APPROACHING 15 C...SHOULD RESULT IN LAKE EFFECT SNOW SHOWERS DOWNWIND OF THE LAKE (MEAN 310-320 LOW LVL FLOW AS IT CURVES INWARD OVER THE SRN HALF OF THE LAKE). AS A RESULT...LIKELY POPS WILL BE PLACE IN ROUGHLY THE NORTHEASTERN 2/3 OF THE CWFA...WITH CHC POPS ELSEWHERE. ACCUMULATING SNOW IS EXPECTED TO BE LIGHTER...RANGING FROM A HALF INCH FAR SWRN CWFA TO NEAR 1.5 INCHES IN THE FAR NORTHEAST. HOWEVER...A STRONG PRESSURE GRADIENT WILL CONTINUE...RESULTING IN SUSTAINED WINDS OF 20 TO 25 MPH WITH GUSTS UP TO 35 MPH...CAUSING CONSIDERABLE DRIFTING AND BLOWING OF SNOW. TEMPERATURES WILL NOT WARM THAT MUCH FROM SUNDAY MORNINGS LOWS...RANGING FROM THE UPPER 20S NORTH TO NEAR 30 SOUTH. FOR SUNDAY NIGHT...LOW PRESSURE WILL CONTINUE TO TRACK NORTHEAST INTO QUEBEC. THUS...SYNOPTIC SCALE SNOWS SHOULD COME TO END...ALTHOUGH A FEW FLURRIES MAY LINGER ON ACRS THE NE CWFA DURING THE EVENING HOURS. WILL CONTINUE WITH A SMALL CHC OF LAKE EFFECT SNOW SHOWERS DOWNWIND OF LAKE MICHIGAN THROUGH SUNDAY NIGHT AS DELTA/TS REMAIN FAVORABLE...ALTHOUGH INVERSION HEIGHTS BEGIN TO DROP SOME. OVERNIGHT LOWS NEAR 20 ALONG THE LAKE MICHIGAN SHORELINE TO THE UPPER TEENS ELSEWHERE APPEAR ON TRACK. FOR MONDAY INTO TUESDAY...UPR LVL CYCLONIC FLOW WILL CONTINUE ACRS SOUTHEASTERN CANADA AND THE NORTHERN GREAT LAKES. THE POTENTIAL EXITS FOR PERHAPS LINGERING LAKE EFFECT SNOW SHOWERS DURING THIS PERIOD...BUT TIMING OF WEAK S/WVS IN THE FLOW ALOFT AND DEPTH OF MOISTURE ARE STILL IN QUESTION AT THIS POINT...SO HAVE OPTED FOR A DRY FORECAST ATTM. FOR WEDNESDAY THROUGH FRIDAY...A FEW CLIPPER SYSTEMS WILL DIVE SOUTHEAST INTO THE GREAT LAKES REGION...BRINGING A CHANCE FOR SNOW. IT LOOKS LIKE AN ARCTIC OUTBREAK IS IN THE OFFING BY NEXT WEEKEND AS THE UPPER LVL PATTERN WILL FEATURE A RIDGE OF HIGH PRESSURE ALL THE WAY UP INTO WRN CANADA...WITH A DEEP POLAR VORTEX OVER HUDSON BAY. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER STORM WARNING FROM 9 AM THIS MORNING TO 7 AM EST SUNDAY FOR INZ007-INZ009-INZ018-INZ026-INZ027-INZ033-INZ034. SNOW AND BLOWING SNOW ADVISORY FROM 9 AM THIS MORNING TO 7 AM EST SUNDAY FOR INZ005-INZ006-INZ008-INZ016-INZ017-INZ024- INZ025-INZ032. SNOW AND BLOWING SNOW ADVISORY FROM 2 PM EST /1 PM CST/ THIS AFTERNOON TO 7 AM EST /6 AM CST/ SUNDAY FOR INZ003-INZ004- INZ014. MI...WINTER STORM WARNING FROM 9 AM THIS MORNING TO 7 AM EST SUNDAY FOR MIZ081. SNOW AND BLOWING SNOW ADVISORY FROM 9 AM THIS MORNING TO 7 AM EST SUNDAY FOR MIZ079-MIZ080. SNOW AND BLOWING SNOW ADVISORY FROM 2 PM THIS AFTERNOON TO 7 AM EST SUNDAY FOR MIZ077-MIZ078. OH...WINTER STORM WARNING FROM 9 AM THIS MORNING TO 7 AM EST SUNDAY FOR OHZ001-OHZ002-OHZ004-OHZ005-OHZ015-OHZ016-OHZ024-OHZ025. LM...GALE WARNING FROM 4 PM THIS AFTERNOON TO 6 PM EST SUNDAY FOR LMZ043-LMZ046. && $$ SHORT TERM...HITCHCOCK LONG TERM....HICKMAN AVIATION...HICKMAN in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1020 PM EST SAT FEB 4 2006 .UPDATE...XTRMLY BUSY SHIFT. STILL SORTING THRU REPORTS IN FREDERICK/CARROLL MD TRYING TO DETERMINE WHAT HAPPENED. COLDER AIR NOW MOVG IN. WSW RMNS INTACT...AS DOES SCA. WOODY! .SHORT TERM (TONIGHT THROUGH SUNDAY)... LOW PRES OVR THE NRN WV PANHANDLE WILL LIFT NORTH INTO SRN ONTARIO TONIGHT WITH STRONG CDFNT SWEEPING THRU THE AREA EARLY THIS EVENING. LATEST GFS AND RUC40 SHOWS A FORCED LINE OF CONVECTION ACCOMPANYING FRONT AROUND 00Z. THIS LINE CAN BE SEEN ALREADY ON REGIONAL RADARS OVER SWRN VA. MODEL GUIDANCE SHOWS THIS BAND OF SHRA/TSRA LIFTING NORTH INTO SRN PA BY 03Z. AFTER THAT EXPECT PARTIAL CLEARING E OF THE MTNS WITH UPSLOPE SHSN PICKING UP OVER THE HIGHLANDS. WINTER WX ADVISORY ISSUED FOR THOSE AREAS AS FLOW MAINLY WESTERLY NOT TOO CONDUCIVE FOR BIG SNOWS. CYCLONIC FLOW AND CAA WILL CONTINUE TO SUPPORT MTN SHSN. A FEW FLURRIES COULD ALSO MAKE IT EAST OF THE MTNS AS UPPER LVL ENERGY PASSES BY AROUND H5 LOW OVER SRN ONTARION. TEMPS BACK TO SEASONABLE NORMS. && .LONG TERM (SUNDAY NIGHT THROUGH SATURDAY)... SUN NGT WILL FEATURE SCTD SN SHWRS CONTINUING IN THE WEST...PRIMARILY IN THE ALLEG FRONT REGION...DUE TO WEAK U/L IMPULSES IN THE BASE OF MAJOR TROUGH AS WELL AS UPSLOPE AND LAKE ENHANCEMENTS. E OF THE BLUE RIDGE SHOULD REMAIN DRY. ALTHOUGH PATTERN SHIFT IS GOING TO BE A SHOCK TO THE SYSTEM...IN REALITY TEMPS WILL GNRLY BE AROUND NORMAL THROUGH THIS EXTENDED PERIOD FOR LATE WINTER. HIGHS IN THE 30S AND 40S AND LOWS IN THE 20S. THIS IS NORMAL. DEEP TROUGHING HWVR WILL BE PERSISTENT BASICALLY THROUGH THIS PERIOD...AND WE SEE NO REASON FOR THIS PATTERN TO CHANGE ANY TIME SOON. HWVR W/O ANY MAJOR SYSTEMS TO MOVE INTO THE REGION...DO NOT SEE ANY BIG SNOW MAKERS. NEXT WEEKEND WILL CONTINUE TO ADVERTISE A LITTLE BETTER CHANCE FOR SN SWRS HWVR DUE TO CLIPPER SYSTEM DROPPING OUT THE GRT LKS. && .AVIATION...IFR CONDTIONS THRU 03Z WITH A CHANCE OF A TSTM THRU 00Z. VFR CONDITIONS AFTER 03Z WITH A SW WIND 10-15KT. && .MARINE...SCA ALL WATERS LOOKS TO PERSIST THROUGH AT LEAST MONDAY DUE TO RATHER STRONG PRES GRAD DUE TO CAA FLOW AND WRLYS. SCA MAY NEED TO BE EXTENDED THROUGH MIDWEEK IF PATTERN HOLDS. TIDE/WATER LEVELS ARE STILL RUNNING ABOUT 1 FT ABOVE PREDICTED LEVELS BUT THESE LEVELS ARE NOW BELOW OUR LOCALLY DEFINED THRESHOLDS FOR MINOR COASTAL FLOODING...THEREFORE WE HAVE ALLOWED THE CSTL FLD STMT TO EXPIRE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...SNOW ADVISORY FOR MDZ002 FROM 7 PM SATURDAY TO 1 AM MONDAY. VA...SNOW ADVISORY FOR VAZ021 FROM 7 PM SATURDAY TO 1 AM MONDAY. WV...SNOW ADVISORY FOR WVZ048-049-054 FROM 7 PM SATURDAY TO 1 AM MONDAY. MARINE...SMALL CRAFT ADVISORY FOR ANZ530>537 UNTIL MONDAY AFTERNOON. && $$ md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 255 PM EST SAT FEB 4 2006 .SHORT TERM (TONIGHT THROUGH SUNDAY)... LOW PRES OVR THE NRN WV PANHANDLE WILL LIFT NORTH INTO SRN ONTARIO TONIGHT WITH STRONG CDFNT SWEEPING THRU THE AREA EARLY THIS EVENING. LATEST GFS AND RUC40 SHOWS A FORCED LINE OF CONVECTION ACCOMPANYING FRONT AROUND 00Z. THIS LINE CAN BE SEEN ALREADY ON REGIONAL RADARS OVER SWRN VA. MODEL GUIDANCE SHOWS THIS BAND OF SHRA/TSRA LIFTING NORTH INTO SRN PA BY 03Z. AFTER THAT EXPECT PARTIAL CLEARING E OF THE MTNS WITH UPSLOPE SHSN PICKING UP OVER THE HIGHLANDS. WINTER WX ADVISORY ISSUED FOR THOSE AREAS AS FLOW MAINLY WESTERLY NOT TOO CONDUCIVE FOR BIG SNOWS. CYCLONIC FLOW AND CAA WILL CONTINUE TO SUPPORT MTN SHSN. A FEW FLURRIES COULD ALSO MAKE IT EAST OF THE MTNS AS UPPER LVL ENERGY PASSES BY AROUND H5 LOW OVER SRN ONTARION. TEMPS BACK TO SEASONABLE NORMS. && .LONG TERM (SUNDAY NIGHT THROUGH SATURDAY)... SUN NGT WILL FEATURE SCTD SN SHWRS CONTINUING IN THE WEST...PRIMARILY IN THE ALLEG FRONT REGION...DUE TO WEAK U/L IMPULSES IN THE BASE OF MAJOR TROUGH AS WELL AS UPSLOPE AND LAKE ENHANCEMENTS. E OF THE BLUE RIDGE SHOULD REMAIN DRY. ALTHOUGH PATTERN SHIFT IS GOING TO BE A SHOCK TO THE SYSTEM...IN REALITY TEMPS WILL GNRLY BE AROUND NORMAL THROUGH THIS EXTENDED PERIOD FOR LATE WINTER. HIGHS IN THE 30S AND 40S AND LOWS IN THE 20S. THIS IS NORMAL. DEEP TROUGHING HWVR WILL BE PERSISTENT BASICALLY THROUGH THIS PERIOD...AND WE SEE NO REASON FOR THIS PATTERN TO CHANGE ANY TIME SOON. HWVR W/O ANY MAJOR SYSTEMS TO MOVE INTO THE REGION...DO NOT SEE ANY BIG SNOW MAKERS. NEXT WEEKEND WILL CONTINUE TO ADVERTISE A LITTLE BETTER CHANCE FOR SN SWRS HWVR DUE TO CLIPPER SYSTEM DROPPING OUT THE GRT LKS. && .AVIATION...IFR CONDTIONS THRU 03Z WITH A CHANCE OF A TSTM THRU 00Z. VFR CONDITIONS AFTER 03Z WITH A SW WIND 10-15KT. && .MARINE...SCA ALL WATERS LOOKS TO PERSIST THROUGH AT LEAST MONDAY DUE TO RATHER STRONG PRES GRAD DUE TO CAA FLOW AND WRLYS. SCA MAY NEED TO BE EXTENDED THROUGH MIDWEEK IF PATTERN HOLDS. TIDE/WATER LEVELS ARE STILL RUNNING ABOUT 1 FT ABOVE PREDICTED LEVELS BUT THESE LEVELS ARE NOW BELOW OUR LOCALLY DEFINED THRESHOLDS FOR MINOR COASTAL FLOODING...THEREFORE WE HAVE ALLOWED THE CSTL FLD STMT TO EXPIRE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...SNOW ADVISORY FOR MDZ002 FROM 7 PM SATURDAY TO 1 AM MONDAY. VA...SNOW ADVISORY FOR VAZ021 FROM 7 PM SATURDAY TO 1 AM MONDAY. WV...SNOW ADVISORY FOR WVZ048-049-054 FROM 7 PM SATURDAY TO 1 AM MONDAY. MARINE...SMALL CRAFT ADVISORY FOR ANZ530>537 UNTIL MONDAY AFTERNOON. && $$ SHORT TERM...ROSA LONG TERM...JB AVIATION...ROSA MARINE...JB md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1100 AM EST SAT FEB 4 2006 FCST GENERALLY IN GOOD SHAPE BUT UPDATED SECOND PERIOD TO ADD THUNDER AND INCREASE POPS FOR THE EARLY EVENING AS LATEST GFS AND RUC SHOW A FORCED LINE OF CONVECTION ACCOMPANYING FRONT AROUND 00Z. THIS LINE IS ALREADY SEEN ON RADAR IMAGERY AFFECTING SRN WV AND SWRN VA. REST OF THE FCST LEFT ALONE. ROSA PREVIOUS AFD... .SHORT TERM (TODAY THROUGH TONIGHT)... SURFACE ANALYSIS FROM 06Z SHOWS LOW PRESSURE CENTERED OVER THE GREAT LAKES...WITH A FRONT EXTENDING SOUTH INTO INDIANA. ANOTHER LOW WAS LOCATED OVER FAR NORTHEASTERN GEORGIA...WITH A FRONTAL BOUNDARY WEAVING INTO NORTH INTO SOUTHERN VIRGINIA...AND SOUTH OVER THE GULF OF MEXICO. OBSERVATIONS SHOW TEMPERATURES RANGING FROM THE MID 30S...WITH DEW POINTS IN THE UPPER 30S. MAIN FOCUS FOR TODAY AND TONIGHT IS THE LOW PRESSURE SYSTEM PASSING TO THE WEST...AND THE FOLLOWING COLD FRONT OVERNIGHT. RAIN WILL ADVANCE ACROSS THE FORECAST AREA LATER THIS MORNING AND CONTINUE THROUGH TONIGHT. MODELS ARE TRENDING FARTHER WEST WITH THE POSITION OF THE SURFACE LOW...AND SLOWER WITH THE ONSET OF PRECIPITATION. FOR NOW...EXPECTING RAIN TO REACH THE SOUTHERN AND WESTERN FORECAST AREA BETWEEN 12 AND 15Z...AND QUICKLY PUSH NORTH. WARMING AHEAD OF THE SYSTEM WILL ALLOW ENOUGH DESTABILIZATION FOR AT LEAST THE POTENTIAL FOR THUNDER. COLDER AIR ARRIVES AFTER 00Z WITH THE COLD FRONT AND WILL HELP TO CHANGE RAIN TO SNOW IN THE WEST. WINTER PRECIPITATION ONLY ADVANCES AS FAR WEST AS THE BLUE RIDGE OVERNIGHT...STILL LEAVING RAIN IN THE EAST. ACCUMULATIONS UP TO TWO INCHES ARE POSSIBLE IN THE FAR WESTERN RIDGES OVERNIGHT...WITH LITTLE OR NO ACCUMULATION ELSEWHERE. && .AVIATION... CONDITIONS WILL QUICKLY DETERIORATE THROUGH THE MORNING AS LOW PRESSURE PASSES TO THE WEST. A BROAD AREA OF RAIN WILL REACH KCHO AROUND 12Z...AND THEN QUICKLY ADVANCE TO THE NORTH BY 15Z. WINDS WILL ALSO INCREASE LATER THIS AFTERNOON. CEILINGS BELOW 1000 FT AND VISIBILITIES AROUND 4SM...LOCALLY DOWN TO 1SM IN HEAVIER RAIN...ARE ALSO EXPECTED...MAINLY BETWEEN 17Z AND 21Z. && .LONG TERM (SUNDAY THROUGH FRIDAY)... EASTERN CONTINENTAL TROF AND WINTER FINALLY RETURNS AFTER A MONTH AND A HALF OFF. MORE SEASONABLE TEMPERATURES WILL RETURN FOR THE UPCOMING WEEK. IT WILL BE NOTHING EXCEPTIONALLY COLD... BUT AFTER THE PAST FEW WEEKS THAT WE HAVE EXPERIENCED AROUND HERE... IT WILL FEEL PRETTY COLD. TIME TO FIND THE WINTER COATS AGAIN. BY 12Z SUN THE ENTIRE FA IS BETWEEN MINUS 2 AND MINUS 8 AT 850MB... THE LOW IS OVER SOUTHERN ONTARIO JUST E OF LAKE HURON... AND THE ENTIRE AREA IS UNDER WESTERLY FLOW AND COLD ADVECTION. SHOULD BE A BLUSTERY COOL AND RATHER SEASONABLE DAY FOR EARLY FEBRUARY. UPSLOPE CLOUDS AND SNOW SHOWERS SHOULD CONTINUE THROUGH THE DAY AND INTO SUNDAY EVENING BEFORE ENDING. SEVERAL INCHES OF UPSLOPE SNOW ARE POSSIBLE ALONG AND WEST OF THE EASTERN CONT DIVIDE FROM LATE SATURDAY EVENING THROUGH LATE SUNDAY NIGHT. WINTER STORM WATCH WILL REMAIN IN EFFECT FOR THOSE AREAS. EAST OF THE DIVIDE FOR MOST OF OUR AREA ON SUNDAY ONLY SOME COLD ADV STRATOCU ARE POSSIBLE. MODEL SOUNDING DO NOT INDICATE AN EXTENSIVE STRATOCU EVENT... BUT PROB ENOUGH FOR A BORDERLINE SCT TO BKN CLOUD DECK. WINDS WILL SUBSIDE A BIT LATE SUN NIGHT...BUT A BREEZE WILL REMAIN. MONDAY A SHORT WAVE PASSES WELL TO OUR S WITH 850MB TMPS EVEN COLDER RANGING FROM MINUS 8 TO MINUS 13 ACROSS THE REGION. FOR THE REST OF THE WEEK... COLD TEMPS AND CLIPPER SYSTEMS BRINGING CHC TO SLGHT CHCS OF QUICK SNOW EVENTS. NO MAJOR STORMS FORECAST FOR THE UPCOMING WEEK. && .MARINE... SMALL CRAFT CONDITIONS ARE EXPECTED LATER THIS AFTERNOON AS PRESSURE GRADIENT TIGHTENS WITH ASSOCIATED LOW PRESSURE SYSTEM TO THE WEST. REDUCED VISIBILITIES WITHIN AREAS OF HEAVY RAIN CAN ALSO BE EXPECTED. SMALL CRAFT CONDITIONS WILL CONTINUE AT LEAST THROUGH LATE SUNDAY EVENING. EXPECT THEM TO FALL JUST BELOW CRITERIA AFTER THAT AND INTO MONDAY. POSSIBILITY OF GALES ON SUNDAY... BUT AT THIS POINT THINK A STRONG SMALL CRAFT EVENT IS MORE LIKELY WITH GUSTS TO 30 KT. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WINTER STORM WATCH FOR MDZ002 FROM 7 PM SATURDAY TO 1 AM MONDAY. VA...WINTER STORM WATCH FOR VAZ021 FROM 7 PM SATURDAY TO 1 AM MONDAY. WV...WINTER STORM WATCH FOR WVZ048-049-054 FROM 7 PM SATURDAY TO 1 AM MONDAY. MARINE...SMALL CRAFT ADVISORY FOR ANZ530>537 FROM 5 PM SATURDAY TO 1 AM MONDAY. && $$ SHORT TERM...ALLEN LONG TERM...STRONG AVIATION...ALLEN MARINE...ALLEN/STRONG md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1123 AM EST SAT FEB 4 2006 .SHORT TERM (REST OF TONIGHT)... LOOKING AT CURRENT RADAR AND SATELLITE DATA AND GFS, NAM AND RUC RUNS ON GOING FCST PKG ON TARGET. QUIET TIME NOW BUT WX GETS ACTIVE THIS PM. && .PREVIOUS DISCUSSION... (ISSUED 514 AM EST SAT FEB 4 2006) SHORT TERM (TODAY THROUGH SUNDAY)... LOW CLOUDS EXITED THE REGION OVERNIGHT BUT PATCHY DENSE GROUND FOG PERSISTED LATE THIS MORNING IN SOME AREAS. TEMPERATURES WERE BELOW FREEZING IN SOME FOGGY AREAS OF WESTERN MA AND SW NH...THUS SOME BLACK ICE MAY BE PRESENT AROUND DAYBREAK. HIGH CLOUDS HAVE ALREADY OVERSPREAD THE REGION AHEAD OF THE NEXT STORM SYSTEM WHICH IS HEADED OUR WAY. LOW PRESSURE OVER SOUTHEAST KY AND EASTERN TN WILL INTENSIFY AS IT MOVES NORTH TO THE EASTERN GREAT LAKES TONIGHT. ITS WARM FRONT WILL MOVE INTO SE NEW ENGLAND TONIGHT...FOLLOWED BY ITS COOL FRONT EARLY SUNDAY MORNING. LOTS OF THUNDERSTORMS ARE OCCURRING IN THE MTNS OF NORTH CAROLINA AND OFF THE CAROLINA COAST AT THE MOMENT. RAIN WILL MOVE STEADILY NORTH TODAY...OVERSPREADING CT...RI...AND SE MA AROUND 3-4 PM AND REACHING SOUTHERN NH BY THIS EVENING. THE RAIN MAY BE HEAVY AT TIMES THIS EVENING AS STRONG VERTICAL MOTION MOVES ACROSS THE AREA. THERE IS ALSO A CHANCE OF A TSTM...MAINLY S OF THE MASS PIKE. BOTH GFS AND NAM BRING BATCH OF TOTAL TOTAL INDICES OF 50+ FROM SW TO NE ACROSS SOUTHERN NEW ENGLAND OVERNIGHT...THE ETA APPEARS TOO SLOW. E TO SE WINDS WILL INCREASE TO 20 MPH WITH GUSTS TO 30 MPH SOUTH COAST/CAPE/ISLANDS LATE THIS AFTERNOON AND TONIGHT. RAINFALL TOTALS SHOULD BE SIMILAR TO THE STORM WE JUST HAD YESTERDAY...GENERALLY 0.75 TO 1.25 INCHES. THIS SHOULD KEEP THINGS MOIST...BUT SHOULD NOT BE ENOUGH TO CAUSE SMALL STREAM FLOODING AS FLASH FLOOD GUIDANCE INDICATES BETWEEN 2 AND 2.5 INCHES WOULD BE NEEDED TO CAUSE FLOODING. AFTER COOL FRONT PASSES ON SUNDAY...WINDS WILL STILL BE OUT OF THE SOUTHWEST AND THERE SHOULD BE SUFFICIENT MIXING OVER THE CAPE AND ISLANDS LATE SUNDAY AFTERNOON TO PRODUCE GUSTS TO 30 TO 40 MPH. WILL HAVE TO WATCH THIS FOR POTENTIAL WIND ADVISORY IF FORECASTING ANY STRONGER. SINCE THE STRONGEST COLD ADVECTION IS DELAYED UNTIL SUNDAY NIGHT...HAVE UPPED HIGH TEMPERATURES FOR SUNDAY TO BE IN LINE WITH NEW GUIDANCE...ROUGHLY 45 TO 50 SE AREAS AND 40 TO 45 NW AREAS SUNDAY. LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)... MEDIUM RANGE MODELS IN PRETTY GOOD AGREEMENT WITH THE AMPLIFICATION OF THE WESTERN RIDGE THROUGH THE MIDDLE OF NEXT WEEK. EVEN THOUGH THE EAST WILL BE UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH... APPEARS THAT ANY THREATENING WEATHER WILL STEER CLEAR THROUGH MID WEEK AT THE EARLIEST. AS THE LOW SPINS ITS WAY INTO WESTERN QUEBEC...SOUTHWEST WINDS WILL INCREASE ESPECIALLY ON THE SOUTH COAST...CAPE AND ISLANDS. COULD GET CLOSE TO ADVISORY CRITERIA...BUT NOT TOTALLY CONFIDENT THAT THIS WILL OCCUR RIGHT NOW. THE VORTEX AND ASSOCIATED LONG WAVE UPPER LEVEL TROUGH WILL REMAIN IN PLACE ACROSS THE EASTERN U.S. THROUGH MID WEEK. BOTH THE NAM AND GFS BUFKIT RELATIVE HUMIDITY CROSS SECTIONS INDICATE SOME LEFTOVER MOISTURE AT AROUND 3-4KFT WHICH COULD HANG THE CLOUDS IN SUNDAY NIGHT...BUT EXPECT THOSE TO BREAK UP AND SKIES TO BECOME PARTLY CLOUDY ON MONDAY. WITH THE LOW IN PLACE OVER EASTERN CANADA...EXPECT DRY CONDITIONS TO REMAIN IN PLACE WITH VARYING AMOUNTS OF CLOUDS AND MOSTLY CLEAR SKIES THROUGH WEDNESDAY. ONLY POTENTIAL THREAT APPEARS TO BE PASSING WELL SOUTH OF THE REGION. WEAK LOW PRESSURE WILL FORM OVER ALABAMA AND MISSISSIPPI ON MONDAY...AND WILL EXIT THE CAROLINA COAST MONDAY NIGHT. THE MODELS ARE IN GOOD AGREEMENT ON THIS FEATURE NOW. GFS HINTING AT A DRY ARCTIC FRONT WORKING ACROSS NORTHERN NEW YORK STATE AND NORTHERN NEW ENGLAND EARLY TUESDAY...AS SEEN WITH THE STRONG 850 HPA TEMPERATURE PACKING AS IT APPROACHES DURING TUESDAY. BY THEN...THE CANADIAN VORTEX WILL MOVE NORTHEAST...ALLOWING THE COLDER AIR TO SPILL INTO THE REGION. WINDS WILL BE DIMINISHING BY TUESDAY MORNING...BUT COULD PICK UP AGAIN LATER TUESDAY AND TUESDAY NIGHT. NOT TOTALLY CONFIDENT ON THIS TIMING...WHICH IS DEPENDENT UPON THE EXIT OF THE CANADIAN VORTEX...SO STUCK TO THE CONTINUITY OF THE PREVIOUS FORECAST FOR TUESDAY NIGHT AND WEDNESDAY. APPEARS THE NEXT THREAT OF ANY SENSIBLE WEATHER WILL BE WITH A CLIPPER SYSTEM DURING THURSDAY THAT WORKS SOUTHEAST OUT OF NORTH CENTRAL CANADA OVER THE TOP OF THE LARGE RIDGE. PREVIOUS FORECAST COVERED THIS WELL...THOUGH TIMING MAY BE IN QUESTION BASED ON THE 00Z GFS RUN. HOWEVER...WITH SOME MODEL SOLUTION SPREAD WITH THIS SYSTEM...HAVE KEPT PREVIOUS FORECAST INTACT FOR NOW. AVIATION... PATCHY IFR CONDS IN GROUND FOG UNTIL 13Z MAINLY AT BAF AND ACK. OTHERWISE HIGH CLOUDS WILL LOWER TO 6000 FT TO 12000 FT BETWEEN 15 AND 18Z FOLLOWED BY MVFR CIGS AND VSBYS IN RAIN FROM SOUTH TO NORTH BETWEEN 19Z AND 22Z...THEN IFR CIGS AND VSBYS WITH RAIN AND FOG WITH A CHANCE OF TSTMS AFT 00Z. MARINE... IN THE SHORT TERM...SEAS UP AT 8 FT AT BUZZARDS BAY DUE TO SW FLOW. SHOULD SUBSIDE AS WINDS SHIFT TO NE AND E THIS AFTERNOON...BUT E TO SE WINDS WILL INCREASE TO 20 KT GUSTING TO 25 TO 30 KT LATE THIS AFTERNOON AND TONIGHT OVER THE SOUTHEASTERN WATERS. SW WINDS WILL INCREASE TO STRONG SMALL CRAFT ADVISORY LEVELS SUNDAY AFTERNOON WITH GALE FORCE GUSTS POSSIBLE IN THE OUTER WATERS FROM MONTAUK TO PROVINCETOWN LATE SUNDAY AFTERNOON. SEAS WILL BUILD UP TO 12 FT ON SUNDAY OVER THE OUTER WATERS...MARINERS SHOULD MONITOR THE LATEST FORECASTS. IN THE LONG TERM...GALE FORCE WINDS WILL CONTINUE ON THE OFFSHORE WATERS FROM PROVINCETOWN TO MONTAUK AS COLD AIR ADVECTION CONTINUES INTO MONDAY NIGHT ALONG WITH STRONG PRESSURE GRADIENT FROM THE LOW THAT SLOWLY MOVES THROUGH QUEBEC. AS THE LOW FINALLY MOVES INTO NORTHERN QUEBEC...THE GRADIENT RELAXES AND WINDS WILL DIMINISH TO SMALL CRAFT CRITERIA BY 12Z TUESDAY. WINDS COULD SURGE BRIEFLY AGAIN TUESDAY AFTERNOON AND EVENING AS DRY ARCTIC FRONT CROSSES THE WATERS...BUT TIMING IS STILL SOMEWHAT IN QUESTION SO WILL HOLD OFF ON THAT FOR NOW. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...GALE WARNING FOR ANZ254-255 FROM 4 PM SUNDAY TO 6 PM SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ232>235-237-250 UNTIL 4 PM SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ230-236 FROM 5 PM SATURDAY TO 11 PM SATURDAY. ...SMALL CRAFT ADVISORY FOR ANZ231 FROM 5 PM SATURDAY TO 4 PM SUNDAY. $$ ma AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1000 PM EST SAT FEB 4 2006 .UPDATE... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN AMPLIFIED PATTERN OVER THE CONUS WITH A DEEPENING TROF FROM THE GREAT LAKES TO THE GULF OF MEXICO. STRONG SHORTWAVE WITHIN TROF IS IN THE PROCESS OF CLOSING OFF A MIDLEVEL LOW OVER FAR SE LWR MI. NW EDGE OF COLD CONVEYOR/DEFORMATION PCPN ASSOCIATED WITH THE SYSTEM HAS OCCASIONALLY SLIPPED INTO THE ERN FCST AREA...AND IR SATELLITE IMAGERY INDICATES DEEPER MOISTURE IS EDGING W ACROSS E HALF OF UPPER MI/LAKE SUPERIOR. AS A RESULT...KMQT RADAR HAS SHOWN AN EXPANSION OF -SN STREAMING OFF LAKE SUPERIOR THIS EVENING UNDER NRLY FLOW. TO THE W...LES HAS BEEN OCCURRING OVER WRN UPPER MI...BUT HAS BEEN GENERALLY LIGHT. KIWD OB HAS SHOWN VSBY DOWN TO AROUND 1SM AT TIMES...BUT CALLS TO SPOTTERS IN THAT AREA INDICATED SNOW WAS NOT VERY HVY...A COUPLE OF INCHES DURING THE AFTN UP TO 23Z. HEAVIER SNOW AMOUNTS HAVE BEEN REPORTED ACROSS THE BORDER IN NW WI...PERHAPS FROM LOCALLY ENHANCED CONVERGENCE. THE AREA NW OF KIWD TOWARD LITTLE GIRLS POINT MIGHT BE SEEING HEAVIER LES...BUT HAVE BEEN UNABLE TO REACH ANY SPOTTERS IN THAT AREA. MORE RECENTLY...KIWD OB HAS SHOWN SOME IMPROVEMENT IN VSBY...AND SPOTTERS IN KIWD VCNTY HAVEN'T REPORTED ANY INCREASE IN SNOW INTENSITY THIS EVENING. BIGGEST CONCERN FOR THE OVERNIGHT IS POSSIBILITY OF REISSUING HEADLINES FOR THE FAR W WITH LONG FETCH ACROSS WRN LAKE SUPERIOR. MODELS INDICATE LOWEST 850MB TEMPS OVER WRN LAKE SUPERIOR (-12 TO -13C) WHICH AGREES WELL WITH SOUNDINGS FROM EARLY EVENING FLIGHTS OUT OF CYQT AND KDLH. ON THE NEGATIVE SIDE...DEEP MOISTURE FROM INTENSIFYING SYSTEM TO THE SE NEVER QUITE SPREADS AS FAR W AS WRN LAKE SUPERIOR. THIS LEAVES RELATIVELY SHALLOW MOISTURE LAYER BLO INVERSION BASED BTWN 900-850MB PER 00Z RUC/21Z LOCAL LAPSWRF RUN. IN ADDITION...FLOW ABOVE 950MB HAS ENOUGH OF AN ERLY COMPONENT TO BE LESS THAN IDEAL FOR ONTONAGON/GOGEBIC COUNTIES. THIS MAY EXPLAIN WHY HEAVIER SNOW HAS BEEN OBSERVED TO THE W OF KIWD. BELIEVE TOTAL NIGHTTIME ACCUMULATIONS WILL REMAIN BLO ADVY OVER ONTONAGON/GOGEBIC COUNTIES...THOUGH IT MAY BE CLOSE FROM THE PORCUPINE MOUNTAINS TO NEAR/JUST W OF KIWD. A BIT TO THE E...WITH DEEPER MOISTURE EDGING W...SNOW/WIND HAS INCREASED SOME RECENTLY ON THE KEWEENAW PENINSULA WITH SPOTTER AT MOHAWK REPORTING ABOUT 1/4SM VSBY IN SN/BLSN AS OF 0110Z. NNE FLOW IS CERTAINLY NOT THE BEST FOR ACCUMULATING SNOW ON THE KEWEENAW...AND IT ALSO MINIMIZES OVERALL EXPOSURE TO STRONG WINDS AND THUS WIDESPREAD BLSN. WHILE FCST WILL CONTINUE TO MENTION BLSN ON THE KEWEENAW...DON'T BELIEVE BLSN WILL BE WIDESPREAD ENOUGH TO SUPPORT ADVY...AND NOT EXPECTING MORE THAN 1-2 INCHES OF ADDITIONAL SNOW THERE OVERNIGHT. FARTHER E...NCNTRL UPPER MI IS IN MUCH BETTER SHAPE FOR ACCUMULATING SNOW. INCREASE IN MOISTURE DEPTH HAS ALREADY RESULTED IN EXPANSION/INCREASE IN INTENSITY OF SNOW ACROSS ERN LAKE SUPERIOR INTO NCNTRL UPPER MI. FAVORABLE UPSLOPING N/NNE FLOW WILL FURTHER BOOST SNOW AMOUNTS FOR THE HIGHER TERRAIN. MIGHT SEE AN ADDITIONAL 3-4 INCHES OF SNOW IN THE HIGHER TERRAIN FROM CHAMPION TO NEGAUNEE...SKANDIA TO WRN ALGER COUNTY. CONSIDERED ADDING BARAGA COUNTY TO ADVY GIVEN FAVORABLE UPSLOPE FLOW...BUT MARGINAL ADVY TYPE ACCUMULATIONS SHOULD BE CONFINED TO A SMALL AREA OVER THE HURON MOUNTAINS. && .PREV DISCUSSION... ISSUED AT 355 PM EST MAIN FORECAST CONCERN IS SNOWFALL AMOUNTS AND HEADLINES FOR THE SHORT-TERM. CURRENT WEATHER...20Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED AN UPPER LEVEL TROUGH COVERING THE ENTIRE MISSISSIPPI VALLEY WITH RIDGING OVER THE INTERMOUNTAIN WEST AND IN THE NORTHEAST. A SHRTWV CAN BE SEEN ROTATING NE THROUGH THE GREAT SMOKY MOUNTAINS AREA AND A 993MB LOW WAS OBSERVED AT THE SURFACE IN FAR SE OHIO NEAR THE TIP OF THE SHRTWV. THIS LOW IS ALSO LOCATED UNDER A BROAD 120-140KT JET THAT EXTENDING FROM THE FLORIDA PANHANDLE INTO MAINE THAT WAS SEEN ON THE 12Z RAOBS. A NICE WARM CONVEYOR AND COLD CONVEYOR BELT STRUCTURE CAN BE SEEN AROUND THE SURFACE LOW WITH THE COLD CONVEYOR BELT IMPACTING LOWER MICHIGAN WITH SOME LIGHT RAIN...WHICH IS NOW CHANGING OVER TO SNOW. SOME OF THE BELT EVEN EXTENDS INTO THE EAST HALF OF UPPER MICHIGAN WHERE THE RADAR HERE SHOWS SOME LIGHT LAKE EFFECT SNOW FROM MARQUETTE/GWINN EASTWARD TO GRAND MARAIS. VISIBLE SATELLITE IMAGERY AND SURFACE OBS ALSO SHOW LAKE EFFECT SNOWS IMPACTING WESTERN UPPER MICHIGAN INTO NW WISCONSIN. CLEAR SKIES THEN EXIST ACROSS MUCH OF MINNESOTA UNDER A 1023MB RIDGE OF HIGH PRESSURE. THIS AIRMASS IS QUITE DRY AS DEWPOINTS THIS MORNING HAVE BEEN NEAR -10F. 12Z INL SOUNDING MODIFIED FOR THE AIR MOVING ACROSS WESTERN LAKE SUPERIOR STILL YIELDS AN INVERSION AROUND 900MB BUT QUITE A BIT IN THE WAY OF DRY AIR BELOW IT. HIGH CLOUDS ARE MOVING ACROSS THE PLAINS ON THE EAST SIDE OF THE INTERMOUNTAIN WEST RIDGE. THESE HIGH CLOUDS ARE COMING OFF THE PACIFIC...ASSOCIATED WITH A SIGNIFICANT TROUGH MOVING THROUGH THE PACIFIC NORTHWEST AND BRITISH COLUMBIA. FREQUENT LIGHTNING STRIKES AND PLENTY OF WIND HAVE OCCURRED WITH THIS TROUGH. TONIGHT...SHRTWV OVER THE GREAT SMOKY MOUNTAINS WILL CONTINUE HEADING UP TO THE N AND THEN NW AS IT BUILDS MORE RIDGING OVER THE NORTHEAST U.S.. THE RESULT OF THIS SHRTWV MOVEMENT AND INCREASING BAROCLINICITY FROM THE EXTRA RIDGING WILL BE TO STRENGTHEN THE SURFACE LOW. BY 12Z...THE NAM/GFS/UKMET/ECMWF SHOW A 980MB LOW NEAR THE SE END OF GEORGIAN BAY. UPPER MICHIGAN WILL REMAIN IN CYCLONIC FLOW AROUND THE LOW...HOWEVER THE DEEPEST MOISTURE IS PROGGED TO REMAIN OVER THE EASTERN HALF. WINDS WILL ALSO TURN MORE NORTHEASTERLY...FAVORING HEAVIER SNOW POSSIBILITIES TO SHIFT INTO THE HIGHER TERRAIN OF MARQUETTE AND WESTERN ALGER COUNTIES. HAVE MAINTAINED ADVISORIES FOR THESE COUNTIES AND FOLLOWED A 20 TO 1 RATIO WITH QPF SIMILAR TO THAT OF OUR LOCAL WRF RUN...WHICH HAS BEEN DOING WELL SO FAR TODAY WITH QPF. FOR THE WEST...ALTHOUGH THE LAKE EFFECT MAY SPARK UP SOME TONIGHT WITH THE DECREASE IN BOUNDARY LAYER MIXING FROM DIURNAL HEATING...THE LACK OF DEEP MOISTURE ALONG WITH THE MORE NORTHEASTERLY FLOW WILL HOLD DOWN SNOW AMOUNTS. WITH SNOW AMOUNTS SINCE 8 PM LAST NIGHT AT MOST OF 6 INCHES IN FAR WESTERN GOGEBIC COUNTY PER STATE POLICE...WHICH IS NEARLY TWICE BELOW WHAT IS NEEDED FOR A WARNING...HAVE DROPPED THAT WARNING ALONG WITH ALL THE OTHER ADVISORIES. CLOUDS WILL HOLD TEMPERATURES UP TONIGHT...SO EXPECT A SLOW FALL IN READINGS. SUNDAY...SHRTWV IS PROGGED TO CLOSE OFF INTO AN UPPER LOW IN THE MORNING...THEN BOTH THE SURFACE AND UPPER LOWS SHIFT TO NEAR OTTAWA BY 00Z. AS THE SYSTEM HEADS OUT...MUCH OF THE DEEPER MOISTURE WILL LEAVE WITH IT. THE COMBINATION OF THE LOSS OF MOISTURE AND THE DIURNAL CYCLE SHOULD KEEP AMOUNTS DOWN TO NO MORE THAN 3 INCHES. WINDS TURNING BACK TO THE NW WILL FAVOR THIS MAX AREA TO BE EAST OF MARQUETTE WHERE THE LONGEST FETCH OF LAKE MOISTENING EXISTS. INTERIOR SECTIONS SHOULD STAY GENERALLY DRY WITH PERHAPS A FEW FLURRIES AS LOW LEVEL MOISTURE HANGS AROUND. READINGS WILL BE SIMILAR TO TODAY\S SINCE THERE IS LITTLE VERY IF ANY CHANGE IN THE PATTERN PROGGED. THE EXCEPTION IS FOR NEWBERRY SINCE THEY ARE RELATIVELY WARM TODAY. HAVE BLOWING SNOW FOR BOTH TONIGHT AND SUNDAY AS WINDS BECOME GUSTY WITH THE DEEPENING LOW. GALE WARNINGS ARE IN EFFECT TOO FOR LAKE SUPERIOR AS 950MB WINDS INCREASE TO NEAR 40 KT BY SUNDAY MORNING. SUNDAY NIGHT THROUGH MONDAY NIGHT...VERY LITTLE CHANGE IN THE PATTERN IS PROGGED AS THE UPPER LOW BECOMES VERY SLOW TO MOVE OUT. AS A RESULT...LIGHT LAKE EFFECT SNOWS WILL LIKELY CONTINUE WITH FLURRIES OR NO PRECIPITATION IN THE SOUTHERN U.P.. THE LARGEST ACCUMULATIONS...ALBEIT NO MORE THAN 3 INCHES IN EACH 12 HOUR PERIOD...WILL REMAIN TO BE LOCATED IN THE EASTERN U.P. WHERE THEY ARE CLOSEST TO SHRTWV/S ROTATING AROUND THE UPPER LOW. INTERIOR SECTIONS MAY IN FACT PARTIALLY CLEAR OUT TOO THROUGH THIS PERIOD...AND WITH 850MB TEMPS IN THE TEENS BELOW ZERO...WOULD NOT BE SURPRISED FOR A FEW SITES TO GET AROUND ZERO FOR LOWS. 06Z MAV COOP GUIDANCE EVEN SHOWED A FEW OF THE TYPICAL COLD SITES DROPPING TO A FEW DEGREES BELOW ZERO MONDAY NIGHT. LITTLE CHANGE FOR TEMPS ON MONDAY WITH THE SAME AIRMASS OVER THE CWA AS ON SUNDAY. TUESDAY...GFS/ECMWF/UKMET ALL SHOW THE UPPER LOW LIFTING OUT THROUGH QUEBEC...WHICH ALLOWS HEIGHTS TO RISE OVER UPPER MICHIGAN. HOWEVER...LAKE INDUCED TROUGHING WILL CONTINUE AS 850MB TEMPS GRADUALLY WARM INTO THE SINGLE DIGITS ABOVE ZERO. SO THE LAKE EFFECT SNOW WILL CONTINUE...BUT AGAIN ON THE LIGHT VARIETY WITH EVEN DRIER AIR GETTING ADVECTED INTO THE CWA. WITH THE SLIGHT WARMING AT 850MB...SHOULD SEE A FEW MORE DEGREES ADDED ONTO MONDAY\S HIGHS. EXTENDED (WEDNESDAY THROUGH SATURDAY)...PATTERN SHIFT TOWARDS A POSITIVE PNA PATTERN CONTINUES TO BE ADVERTISED...MEANING A CHANGE TOWARDS COLDER WEATHER IS LIKELY. THE SYSTEM THAT IS THE MAIN CAUSE FOR THE CHANGE COMES OFF THE NE PACIFIC ON TUESDAY...THEN MOVES INTO CENTRAL CANADA ON WEDNESDAY. UPPER MICHIGAN AT THIS POINT WILL STILL BE UNDER THE INFLUENCE OF HIGH PRESSURE OVER THE OHIO VALLEY...KEEPING WINDS FROM THE WEST-SOUTHWEST AND ANY LES PUSHED INTO ONTARIO. ANY ISENTROPIC LIFT/WARM ADVECTION SNOW ALSO LOOKS LIKE IT WILL BE HELD OVER MANITOBA AND THE EASTERN DAKOTAS PER 00Z ECMWF/UKMET/CANADIAN. 00Z/06Z GFS APPEAR TO BE TOO FAST WITH THE SYSTEM. ALL MODELS INDICATE RIDGING BEING BUILT UP IN WESTERN CANADA WEDNESDAY NIGHT AND THURSDAY...CAUSING AN UPPER LEVEL TROUGH TO DEVELOP IN CENTRAL CANADA. THIS ALLOWS FOR COLD AIR TO START DROPPING SOUTH...INTENSIFYING THE CLIPPER SYSTEM. 00Z ECMWF/UKMET/CANADIAN SHOW THE LOW CENTER DROPPING INTO NORTH CENTRAL ONTARIO BY 00Z FRI WITH A PRESSURE AROUND 989MB. GIVEN THE PRESSURE...WOULD EXPECT THAT WEDNESDAY NIGHT AND THURSDAY WILL BE QUITE BREEZY...ALONG WITH SOME WARM ADVECTION SNOWS MOVING ACROSS THE U.P.. ON FRIDAY...A REX BLOCK FORMS IN THE WESTERN NORTH AMERICA WITH RIDGING FROM THE EAST PACIFIC INTO THE WESTERN U.S./CANADA AND AN UPPER LOW TRAPPED AROUND BAJA CALIFORNIA. WITH A REX BLOCK IN THE WEST...THIS FAVORS AN UPPER TROUGH IN THE UPPER MISSISSIPPI VALLEY AND THE GREAT LAKES...WHICH IS EXACTLY THE MODELS SHOW. AS A RESULT...THE ECMWF SHOWS 850MB TEMPS DROPPING TO -26C ACROSS NORTHERN MINNESOTA BY 00Z SAT WITH -20S C ENTERING WESTERN LAKE SUPERIOR. SO FOR FRIDAY AND SATURDAY...HAVE LAKE EFFECT SNOW CHANCES IN THE GRIDS. A COUPLE OF BELOW ZERO NIGHTS ARE LIKELY...ESPECIALLY IN THE INTERIOR AWAY FROM WHERE THE LES OCCURS. DESPITE THE VERY COLD AIR...WHICH RESULTS IN QUITE A BIT OF INSTABILITY OVER LAKE SUPERIOR...THE AIR WILL LIKELY BE DRY. THEREFORE WILL NOT MENTION ANYTHING ABOUT SIGNIFICANT LAKE EFFECT SNOW IN THE HWO. && .MQT WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST SUN MIZ005-006. GALE WARNING EAST 2/3RDS OF LAKE SUPERIOR. && $$ ROLFSON (UPDATE) AJ (PREV DISCUSSION) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 825 PM EST SAT FEB 4 2006 .UPDATE.. UPDATED TO DOWNGRADE THE WARNING IN WASHTENAW...LENAWEE AND MONROE COUNTIES TO A SNOW/BLOWING SNOW ADVISORY WITH TEMPERATURES ABOVE FREEZING THIS EVENING...ACCUMULATION HAS BEEN HARD TO COME BY. THE MAIN SURGE OF MOISTURE IS NOW BACKING INTO THE AREA...AND WITH WITH TEMPERATURES NOW AROUND 33 AND FALLING...EXPECT ACCUMULATION TO COMMENCE. HOWEVER...THESE AREAS ARE ON THE SOUTHWESTERN EDGE OF THE BEST MOISTURE...SO DOUBT THEY WILL DO ANY BETTER THAN 3-5 INCHES OF SNOW...AND LIKELY LESS TOWARD THE OHIO BORDER. LEFT WAYNE COUNTY IN THE WARNING...ALTHOUGH MUCH OF THE COUNTY WILL FALL SHORT OF 6 INCHES GIVEN THE SLOW TURN OVER/ACCUMULATION. EVEN SO...THEY ARE ON THE PIVOT POINT OF THE AFOREMENTIONED SURGE OF MOISTURE...SO EXPECT A PRETTY TIGHT GRADIENT FROM NORTH TO SOUTH ACROSS THE COUNTY WITH THE NORTHERN BORDER PUSHING 5 OR 6 INCHES AND THE SOUTH CLOSER TO 3 MAYBE 4 INCHES BY SUNDAY MORNING. FURTHER NORTH...EXPANDED THE WARNING INTO THE SAGINAW VALLEY (BAY... SAGINAW AND SHIAWASSEE COUNTIES). TEMPERATURES HAVE FINALLY DROP TO FREEZING AND CONTINUE TO FALL. THE MAIN MOISTURE SURGE FROM THE SOUTHEAST IS POINTED RIGHT INTO THIS AREA. 18Z MODELS SUGGESTED 6-7 INCHES OF SNOW IN THE 00Z-12Z TIMEFRAME...AND RADAR/SATELLITE TRENDS NOW BARE THIS OUT. LEFT MIDLAND COUNTY AS AN ADVISORY BEING A BIT TOO FAR WEST. && .AVIATION...ISSUED AT 600 PM ALTHOUGH HEAVIER SNOWFALL HAS BEEN COMING IN POCKETS SO FAR...WITH SOME OF THE LIGHTER PERIODS STILL MIXED WITH RAIN...CONDITIONS WILL REMAIN IN THE IFR RANGE DUE TO LOW CEILINGS. 18Z MODELS ALL INSIST ON A RATHER IMPRESSIVE INCREASE IN SNOWFALL INTENSITY/COVERAGE BY 01/02Z...CARRYING ON THROUGH ABOUT 06-07Z. THERE AREA FINALLY SOME SIGNS OF THIS ON SATELLITE AS A STEADY ENHANCEMENT IN CLOUD FEATURES HAS BEEN ONGOING IN THE SOUTHEAST FEED OF MOISTURE OVER LAKE ERIE BACK TOWARD THE AREA. IN ADDITION...RADAR RETURNS HAVE RESPONDED IN THIS AREA. SO...STILL EXPECT A WINDOW OF MODERATE/HEAVY SNOW IN THE 01Z-05Z TIMEFRAME DTW/DET TRENDING INTO MBS BY 03Z-07Z. WILL TAPER THE SNOW OFF A BIT LATE TONIGHT...BUT KEEP VISIBILITIES DOWN IN THE 1-3SM MILE AREA WITH -SN/BLSN. SNOW WILL THEN TAPER OFF TO FLURRIES ON SUNDAY MORNING...W/ JUST BLSN IN GUSTY NORTHWEST FLOW PERSISTING IN THE AFTERNOON. && .SHORT TERM...TONIGHT AND SUNDAY...ISSUED AT 407 PM 12Z RAOBS/WATER VAPOR LOOP SHOW LONGWAVE TROUGH FROM THE GREAT LAKES TO THE GULF COAST. STRONG SHORTWAVE LIFTING INTO OHIO...WITH SECONDARY ENERGY OVER WISCONSIN/ILLINOIS. WATER VAPOR/HEIGHT ANALYSIS ALREADY SHOWS SIGNS OF CUTTING OFF AS THE SYSTEM WRAPS UP. 18Z ACARS OBSERVATIONS AROUND 30KFT SHOW A WIDESPREAD AREA OF +150KTS...WITH ONE REPORT OF 175KTS. SURFACE ANALYSIS SHOWS LOW OVER SOUTHEASTERN OHIO...WITH AN INCREASING AREA OF PRESSURE FALLS OVER CENTRAL LAKE ERIE. REGIONAL RADARS SHOW WIDESPREAD PRECIP ACROSS SOUTHEAST MICHIGAN. METARS ACROSS MUCH OF THE CWA HAVE CHANGED OVER TO SNOW...WITH CHANGE OVER WORKING ITS WAY FROM SOUTHEAST TO NORTHWEST. FEW STATIONS IN THE WESTERN AND NORTHERN CWA AWAY FROM THE HEAVIER PRECIP RATES STILL REPORTING RAIN. UPPER TROUGH TAKING ON A NEGATIVE TILT AS THE STRONG UPPER JET/SHORTWAVE LIFTS THROUGH THE OHIO VALLEY. SURFACE LOW CONTINUES TO TAKE A MORE LEFT/NORTHWARD TURN AS WELL...LEADING TO A CONTINUATION OF THE EARLIER WESTWARD TREND AND OVERALL IN LINE WITH THE GOING FORECAST. COMPARED TO 18Z ACARS OBSERVATIONS...12Z RUNS STILL UNDERDO THE STRENGTH OF THE DOWNSTREAM JET...BY ABOUT 6 HOURS AND AT LEAST 10KTS. THIS SHOULD LEAD TO A CONTINUED STRENGTHENING OF THE SURFACE LOW...WITH A FASTER TRACK INTO ONTARIO TONIGHT. THIS COULD LEAD TO A SHORTER PERIOD OF SNOW ACROSS THE SOUTHWESTERN CWA. GOOD MOISTURE FLUX AND FRONTOGENESIS TO THE NORTHWEST OF THE SYSTEM LEADING TO WIDESPREAD PRECIP AND MODEST SNOWFALL RATES ALREADY. SPOTTER REPORTS FROM DTX/PTK SOUTHWARD INDICATE SNOW IS BEGINNING TO ACCUMULATE...WITH UP TO HALF INCH IN 45 MINUTES REPORTED. TAMDAR SOUNDINGS INTO DTW SHOW THE PROFILE ALL BELOW FREEZING...WITH SOUNDINGS FARTHER NORTH AND WEST STILL SHOW FREEZING LEVELS >1.2KFT. ONCE HEAVIER PRECIP MAKES IT NORTHWESTWARD...EXPECT MELTING AND DYNAMIC COOLING TO ALLOW PRECIP TO QUICKLY CHANGE OVER TO ALL SNOW. ONE ADDITIONAL CONCERN IS WITH CONVECTIVE POTENTIAL ACROSS THE SOUTHERN CWA. 18Z RUC CROSS SECTIONS SHOWS WEAK TO NEUTRAL STATIC STABILITY...WHILE THE 12Z NAM IS ACTUALLY CONVECTIVELY UNSTABLE WITH THETA-E FOLDED OVER. LDN ACTUALLY PICKED UP A COUPLE LIGHTNING STRIKES OVER WESTERN LAKE ERIE AND NEAR TOLEDO. AM TEMPTED TO HOLD OFF ON MENTIONING THUNDER AS THE NAM WINDOW OF INSTABILITY IS PRETTY SHORT AND DIMINISHES AFTER 21Z. COULD SEE SOME HEAVY PRECIP RATES THOUGH...AS CAN BE INFERRED FROM SNOW THAT IS ALREADY ACCUMULATING ACROSS THE SOUTHERN CWA. THE FASTER TREND MAY LIMIT THE DURATION OF SNOWFALL ACROSS THE FAR SOUTHWEST...AS THE SYSTEM PULLS OUT FASTER. HOWEVER EXPECT THE SNOWFALL RATES THIS EVENING WITH WEAK STABILITY TO HELP US REALIZE THE WARNING CRITERIA SNOWFALL...AND THEREFORE WILL KEEP THE WARNING GOING. THE WESTWARD TREND WOULD ALLOW THE TROWAL TO SETUP FARTHER WEST AND NORTH ACROSS THE THUMB AND INTO NORTHERN LOWER. WILL BUMP SNOW ACCUMULATIONS UP A BIT OVER TOWARD BAY COUNTY. HOWEVER GIVEN THE SLOWER CHANGEOVER AND QUESTIONABLE ENHANCEMENT THAT FAR WEST WILL KEEP THEM IN AN ADVISORY. ELSEWHERE SNOW TOTAL STILL LOOK GOOD...WITH GREATEST AMOUNT ACROSS THE THUMB WITH SOME ENHANCEMENT IN THE NORTHERLY FLOW OFF HURON. WILL MENTION DEFINITE BLOWING SNOW ACROSS THE CWA TONIGHT AS FORECAST SOUNDINGS/TIME SECTIONS SHOW THE MIXED LAYER TAPPING INTO 40KTS A FEW THOUSAND FEET OFF THE SURFACE. GOOD CYCLONIC FLOW ON SUNDAY WITH TRAILING SHORTWAVE SWINGING THOUGH. LAKE EFFECT SETUP IS NOT ALL THAT IMPRESSIVE...ALTHOUGH SOME SYNOPTIC LIFT WITH RELATIVELY DEEP MOISTURE PRESENT COULD LEAD TO SOME ENHANCEMENT. THEREFORE WILL HOLD ONTO LIKELY POPS AT LEAST THROUGH THE MORNING DESPITE A QUICKER DEPARTURE TO THE SYSTEM. ADDED AREA OF BLOWING SNOW AS WELL WITH A STRONG GRADIENT AND CONTINUED DEEP MIXED LAYER. && .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...ISSUED AT 407 PM WEEKEND SURFACE LOW SLOWLY RETREATING NORTHEAST THROUGH QUEBEC THROUGH EARLY PART OF WEEK AS ASSOCIATED CYCLONIC FLOW BACK ACROSS THE FORECAST AREA AND EASTERN GREAT LAKES REGION SLOWLY WANES. AT THE SAME TIME...THE CLOSED STACKED LOW ALOFT VERY SLOWLY RETREATING NORTH/NORTHEAST. AFTER MODEST DEEPER MOISTURE WANES SUNDAY NIGHT...ESPECIALLY SOUTH...THIS DEEPER MOISTURE RATHER MEAGER THROUGH EARLY PART OF WEEK. LOWER LEVEL RELATIVE HUMIDITIES...ON THE OTHER HAND...REMAIN GENERALLY HIGH THROUGH EARLY WEEK. DYNAMICS SLIGHT AT BEST FROM TIME TO TIME THROUGH EARLY WEEK...INCLUDING LOW TO MID LEVEL QVECTOR CONVERGENCE...SURFACE CONVERGENCE AND OMEGA LIFT. QPF FIELDS ALSO VERY LIGHT...AND NAM ESSENTIALLY EVEN DRY THROUGH TUESDAY. GFS MODEL SOUNDINGS SHOW BETTER LOW LEVEL MOISTURE THAN NAM... TAPPING COLDER THAN MINUS 10C TEMPERATURES FOR ICE NUCLEI...AND WITH NEARLY DRY ADIABATIC LOW LEVEL LAPSE RATES MUCH OF THE TIME WITH WEST TO NORTHWEST FLOW...HAVE MENTIONED AT LEAST FLURRY CHANCES THROUGH EARLY WEEK. DURING THE MID WEEK PERIOD INTO THE WEEKEND... MODELS SHOW SOME CONSENSUS TOWARD SURFACE RIDGING OVERHEAD WEDNESDAY...THEN CONSIDERABLE TIMING/DETAIL DIFFERENCES AMONG MODELS AS TO BRINGING OF CLIPPER ON DOWN INTO LAKES REGION...WHICH WHEN THIS DOES HAPPEN WILL BE ACCOMPANIED BY A RESURGENCE OF COLD ARCTIC AIR LATE NEXT WEEK. AT 500 MB...CONSIDERABLE DETAIL DIFFERENCES AMONG MODELS ESPECIALLY WITH RESPECT TO TIMING AND PLACEMENT OF INDIVIDUAL SHORTWAVE TROUGH IMPULSES...BUT MAIN IDEA IS FOR LOWERING HEIGHTS LATTER PART OF WEEK...AND WITH AVAILABLE MODELS SHOWING IMPROVED MOISTURE...AMIDST OVERALL WESTERN RIDGE/EASTERN TROUGH SCENARIO PERSISTING...AND WITH BROAD TROUGH PERSISTING INTO THE WEEKEND. AFTER FLURRY CHANCES MENTIONED WEDNESDAY...THE PREVIOUS FORECAST FOR CHANCE OF SNOW SHOWERS THEREAFTER IS HARD TO ARGUE WITH. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WINTER STORM WARNING...MIZ048-MIZ049-MIZ053-MIZ054-MIZ055- MIZ060-MIZ061-MIZ062-MIZ063-MIZ068-MIZ069-MIZ070-MIZ076...UNTIL NOON SUNDAY. SNOW AND BLOWING SNOW ADVISORY...MIZ047-MIZ075-MIZ082-MIZ083 UNTIL NOON SUNDAY. LAKE HURON...GALE WARNING...NEARSHORE AND OPEN WATERS FROM PORT AUSTIN TO PORT HURON INCLUDING SAGINAW BAY...UNTIL 1 AM MONDAY. LAKE ST CLAIR...GALE WARNING...UNTIL 1 AM MONDAY. MI WATERS OF LAKE ERIE...GALE WARNING...UNTIL 1 AM MONDAY. && $$ UPDATE.......DG AVIATION.....DG SHORT TERM...BRAVENDER LONG TERM....DWD YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 600 PM EST SAT FEB 4 2006 .AVIATION... ALTHOUGH HEAVIER SNOWFALL HAS BEEN COMING IN POCKETS SO FAR...WITH SOME OF THE LIGHTER PERIODS STILL MIXED WITH RAIN...CONDITIONS WILL REMAIN IN THE IFR RANGE DUE TO LOW CEILINGS. 18Z MODELS ALL INSIST ON A RATHER IMPRESSIVE INCREASE IN SNOWFALL INTENSITY/COVERAGE BY 01/02Z...CARRYING ON THROUGH ABOUT 06-07Z. THERE AREA FINALLY SOME SIGNS OF THIS ON SATELLITE AS A STEADY ENHANCEMENT IN CLOUD FEATURES HAS BEEN ONGOING IN THE SOUTHEAST FEED OF MOISTURE OVER LAKE ERIE BACK TOWARD THE AREA. IN ADDITION...RADAR RETURNS HAVE RESPONDED IN THIS AREA. SO...STILL EXPECT A WINDOW OF MODERATE/HEAVY SNOW IN THE 01Z-05Z TIMEFRAME DTW/DET TRENDING INTO MBS BY 03Z-07Z. WILL TAPER THE SNOW OFF A BIT LATE TONIGHT...BUT KEEP VISIBILITIES DOWN IN THE 1-3SM MILE AREA WITH -SN/BLSN. SNOW WILL THEN TAPER OFF TO FLURRIES ON SUNDAY MORNING...W/ JUST BLSN IN GUSTY NORTHWEST FLOW PERSISTING IN THE AFTERNOON. && .SHORT TERM...TONIGHT AND SUNDAY...ISSUED AT 407 PM 12Z RAOBS/WATER VAPOR LOOP SHOW LONGWAVE TROUGH FROM THE GREAT LAKES TO THE GULF COAST. STRONG SHORTWAVE LIFTING INTO OHIO...WITH SECONDARY ENERGY OVER WISCONSIN/ILLINOIS. WATER VAPOR/HEIGHT ANALYSIS ALREADY SHOWS SIGNS OF CUTTING OFF AS THE SYSTEM WRAPS UP. 18Z ACARS OBSERVATIONS AROUND 30KFT SHOW A WIDESPREAD AREA OF +150KTS...WITH ONE REPORT OF 175KTS. SURFACE ANALYSIS SHOWS LOW OVER SOUTHEASTERN OHIO...WITH AN INCREASING AREA OF PRESSURE FALLS OVER CENTRAL LAKE ERIE. REGIONAL RADARS SHOW WIDESPREAD PRECIP ACROSS SOUTHEAST MICHIGAN. METARS ACROSS MUCH OF THE CWA HAVE CHANGED OVER TO SNOW...WITH CHANGE OVER WORKING ITS WAY FROM SOUTHEAST TO NORTHWEST. FEW STATIONS IN THE WESTERN AND NORTHERN CWA AWAY FROM THE HEAVIER PRECIP RATES STILL REPORTING RAIN. UPPER TROUGH TAKING ON A NEGATIVE TILT AS THE STRONG UPPER JET/SHORTWAVE LIFTS THROUGH THE OHIO VALLEY. SURFACE LOW CONTINUES TO TAKE A MORE LEFT/NORTHWARD TURN AS WELL...LEADING TO A CONTINUATION OF THE EARLIER WESTWARD TREND AND OVERALL IN LINE WITH THE GOING FORECAST. COMPARED TO 18Z ACARS OBSERVATIONS...12Z RUNS STILL UNDERDO THE STRENGTH OF THE DOWNSTREAM JET...BY ABOUT 6 HOURS AND AT LEAST 10KTS. THIS SHOULD LEAD TO A CONTINUED STRENGTHENING OF THE SURFACE LOW...WITH A FASTER TRACK INTO ONTARIO TONIGHT. THIS COULD LEAD TO A SHORTER PERIOD OF SNOW ACROSS THE SOUTHWESTERN CWA. GOOD MOISTURE FLUX AND FRONTOGENESIS TO THE NORTHWEST OF THE SYSTEM LEADING TO WIDESPREAD PRECIP AND MODEST SNOWFALL RATES ALREADY. SPOTTER REPORTS FROM DTX/PTK SOUTHWARD INDICATE SNOW IS BEGINNING TO ACCUMULATE...WITH UP TO HALF INCH IN 45 MINUTES REPORTED. TAMDAR SOUNDINGS INTO DTW SHOW THE PROFILE ALL BELOW FREEZING...WITH SOUNDINGS FARTHER NORTH AND WEST STILL SHOW FREEZING LEVELS >1.2KFT. ONCE HEAVIER PRECIP MAKES IT NORTHWESTWARD...EXPECT MELTING AND DYNAMIC COOLING TO ALLOW PRECIP TO QUICKLY CHANGE OVER TO ALL SNOW. ONE ADDITIONAL CONCERN IS WITH CONVECTIVE POTENTIAL ACROSS THE SOUTHERN CWA. 18Z RUC CROSS SECTIONS SHOWS WEAK TO NEUTRAL STATIC STABILITY...WHILE THE 12Z NAM IS ACTUALLY CONVECTIVELY UNSTABLE WITH THETA-E FOLDED OVER. LDN ACTUALLY PICKED UP A COUPLE LIGHTNING STRIKES OVER WESTERN LAKE ERIE AND NEAR TOLEDO. AM TEMPTED TO HOLD OFF ON MENTIONING THUNDER AS THE NAM WINDOW OF INSTABILITY IS PRETTY SHORT AND DIMINISHES AFTER 21Z. COULD SEE SOME HEAVY PRECIP RATES THOUGH...AS CAN BE INFERRED FROM SNOW THAT IS ALREADY ACCUMULATING ACROSS THE SOUTHERN CWA. THE FASTER TREND MAY LIMIT THE DURATION OF SNOWFALL ACROSS THE FAR SOUTHWEST...AS THE SYSTEM PULLS OUT FASTER. HOWEVER EXPECT THE SNOWFALL RATES THIS EVENING WITH WEAK STABILITY TO HELP US REALIZE THE WARNING CRITERIA SNOWFALL...AND THEREFORE WILL KEEP THE WARNING GOING. THE WESTWARD TREND WOULD ALLOW THE TROWAL TO SETUP FARTHER WEST AND NORTH ACROSS THE THUMB AND INTO NORTHERN LOWER. WILL BUMP SNOW ACCUMULATIONS UP A BIT OVER TOWARD BAY COUNTY. HOWEVER GIVEN THE SLOWER CHANGEOVER AND QUESTIONABLE ENHANCEMENT THAT FAR WEST WILL KEEP THEM IN AN ADVISORY. ELSEWHERE SNOW TOTAL STILL LOOK GOOD...WITH GREATEST AMOUNT ACROSS THE THUMB WITH SOME ENHANCEMENT IN THE NORTHERLY FLOW OFF HURON. WILL MENTION DEFINITE BLOWING SNOW ACROSS THE CWA TONIGHT AS FORECAST SOUNDINGS/TIME SECTIONS SHOW THE MIXED LAYER TAPPING INTO 40KTS A FEW THOUSAND FEET OFF THE SURFACE. GOOD CYCLONIC FLOW ON SUNDAY WITH TRAILING SHORTWAVE SWINGING THOUGH. LAKE EFFECT SETUP IS NOT ALL THAT IMPRESSIVE...ALTHOUGH SOME SYNOPTIC LIFT WITH RELATIVELY DEEP MOISTURE PRESENT COULD LEAD TO SOME ENHANCEMENT. THEREFORE WILL HOLD ONTO LIKELY POPS AT LEAST THROUGH THE MORNING DESPITE A QUICKER DEPARTURE TO THE SYSTEM. ADDED AREA OF BLOWING SNOW AS WELL WITH A STRONG GRADIENT AND CONTINUED DEEP MIXED LAYER. && .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...ISSUED AT 407 PM WEEKEND SURFACE LOW SLOWLY RETREATING NORTHEAST THROUGH QUEBEC THROUGH EARLY PART OF WEEK AS ASSOCIATED CYCLONIC FLOW BACK ACROSS THE FORECAST AREA AND EASTERN GREAT LAKES REGION SLOWLY WANES. AT THE SAME TIME...THE CLOSED STACKED LOW ALOFT VERY SLOWLY RETREATING NORTH/NORTHEAST. AFTER MODEST DEEPER MOISTURE WANES SUNDAY NIGHT...ESPECIALLY SOUTH...THIS DEEPER MOISTURE RATHER MEAGER THROUGH EARLY PART OF WEEK. LOWER LEVEL RELATIVE HUMIDITIES...ON THE OTHER HAND...REMAIN GENERALLY HIGH THROUGH EARLY WEEK. DYNAMICS SLIGHT AT BEST FROM TIME TO TIME THROUGH EARLY WEEK...INCLUDING LOW TO MID LEVEL QVECTOR CONVERGENCE...SURFACE CONVERGENCE AND OMEGA LIFT. QPF FIELDS ALSO VERY LIGHT...AND NAM ESSENTIALLY EVEN DRY THROUGH TUESDAY. GFS MODEL SOUNDINGS SHOW BETTER LOW LEVEL MOISTURE THAN NAM... TAPPING COLDER THAN MINUS 10C TEMPERATURES FOR ICE NUCLEI...AND WITH NEARLY DRY ADIABATIC LOW LEVEL LAPSE RATES MUCH OF THE TIME WITH WEST TO NORTHWEST FLOW...HAVE MENTIONED AT LEAST FLURRY CHANCES THROUGH EARLY WEEK. DURING THE MID WEEK PERIOD INTO THE WEEKEND... MODELS SHOW SOME CONSENSUS TOWARD SURFACE RIDGING OVERHEAD WEDNESDAY...THEN CONSIDERABLE TIMING/DETAIL DIFFERENCES AMONG MODELS AS TO BRINGING OF CLIPPER ON DOWN INTO LAKES REGION...WHICH WHEN THIS DOES HAPPEN WILL BE ACCOMPANIED BY A RESURGENCE OF COLD ARCTIC AIR LATE NEXT WEEK. AT 500 MB...CONSIDERABLE DETAIL DIFFERENCES AMONG MODELS ESPECIALLY WITH RESPECT TO TIMING AND PLACEMENT OF INDIVIDUAL SHORTWAVE TROUGH IMPULSES...BUT MAIN IDEA IS FOR LOWERING HEIGHTS LATTER PART OF WEEK...AND WITH AVAILABLE MODELS SHOWING IMPROVED MOISTURE...AMIDST OVERALL WESTERN RIDGE/EASTERN TROUGH SCENARIO PERSISTING...AND WITH BROAD TROUGH PERSISTING INTO THE WEEKEND. AFTER FLURRY CHANCES MENTIONED WEDNESDAY...THE PREVIOUS FORECAST FOR CHANCE OF SNOW SHOWERS THEREAFTER IS HARD TO ARGUE WITH. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WINTER STORM WARNING...MIZ049-MIZ054-MIZ055-MIZ061-MIZ062-MIZ063- MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-MIZ082-MIZ083...UNTIL NOON SUNDAY. SNOW AND BLOWING SNOW ADVISORY...MIZ047-MIZ048-MIZ053-MIZ060... UNTIL NOON SUNDAY. LAKE HURON...GALE WARNING...NEARSHORE AND OPEN WATERS FROM PORT AUSTIN TO PORT HURON INCLUDING SAGINAW BAY...UNTIL 1 AM MONDAY. LAKE ST CLAIR...GALE WARNING...UNTIL 1 AM MONDAY. MI WATERS OF LAKE ERIE...GALE WARNING...UNTIL 1 AM MONDAY. && $$ AVIATION.....DG SHORT TERM...BRAVENDER LONG TERM....DWD YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 407 PM EST SAT FEB 4 2006 .SHORT TERM...TONIGHT AND SUNDAY 12Z RAOBS/WATER VAPOR LOOP SHOW LONGWAVE TROUGH FROM THE GREAT LAKES TO THE GULF COAST. STRONG SHORTWAVE LIFTING INTO OHIO...WITH SECONDARY ENERGY OVER WISCONSIN/ILLINOIS. WATER VAPOR/HEIGHT ANALYSIS ALREADY SHOWS SIGNS OF CUTTING OFF AS THE SYSTEM WRAPS UP. 18Z ACARS OBSERVATIONS AROUND 30KFT SHOW A WIDESPREAD AREA OF +150KTS...WITH ONE REPORT OF 175KTS. SURFACE ANALYSIS SHOWS LOW OVER SOUTHEASTERN OHIO...WITH AN INCREASING AREA OF PRESSURE FALLS OVER CENTRAL LAKE ERIE. REGIONAL RADARS SHOW WIDESPREAD PRECIP ACROSS SOUTHEAST MICHIGAN. METARS ACROSS MUCH OF THE CWA HAVE CHANGED OVER TO SNOW...WITH CHANGE OVER WORKING ITS WAY FROM SOUTHEAST TO NORTHWEST. FEW STATIONS IN THE WESTERN AND NORTHERN CWA AWAY FROM THE HEAVIER PRECIP RATES STILL REPORTING RAIN. UPPER TROUGH TAKING ON A NEGATIVE TILT AS THE STRONG UPPER JET/SHORTWAVE LIFTS THROUGH THE OHIO VALLEY. SURFACE LOW CONTINUES TO TAKE A MORE LEFT/NORTHWARD TURN AS WELL...LEADING TO A CONTINUATION OF THE EARLIER WESTWARD TREND AND OVERALL IN LINE WITH THE GOING FORECAST. COMPARED TO 18Z ACARS OBSERVATIONS...12Z RUNS STILL UNDERDO THE STRENGTH OF THE DOWNSTREAM JET...BY ABOUT 6 HOURS AND AT LEAST 10KTS. THIS SHOULD LEAD TO A CONTINUED STRENGTHENING OF THE SURFACE LOW...WITH A FASTER TRACK INTO ONTARIO TONIGHT. THIS COULD LEAD TO A SHORTER PERIOD OF SNOW ACROSS THE SOUTHWESTERN CWA. GOOD MOISTURE FLUX AND FRONTOGENESIS TO THE NORTHWEST OF THE SYSTEM LEADING TO WIDESPREAD PRECIP AND MODEST SNOWFALL RATES ALREADY. SPOTTER REPORTS FROM DTX/PTK SOUTHWARD INDICATE SNOW IS BEGINNING TO ACCUMULATE...WITH UP TO HALF INCH IN 45 MINUTES REPORTED. TAMDAR SOUNDINGS INTO DTW SHOW THE PROFILE ALL BELOW FREEZING...WITH SOUNDINGS FARTHER NORTH AND WEST STILL SHOW FREEZING LEVELS >1.2KFT. ONCE HEAVIER PRECIP MAKES IT NORTHWESTWARD...EXPECT MELTING AND DYNAMIC COOLING TO ALLOW PRECIP TO QUICKLY CHANGE OVER TO ALL SNOW. ONE ADDITIONAL CONCERN IS WITH CONVECTIVE POTENTIAL ACROSS THE SOUTHERN CWA. 18Z RUC CROSS SECTIONS SHOWS WEAK TO NEUTRAL STATIC STABILITY...WHILE THE 12Z NAM IS ACTUALLY CONVECTIVELY UNSTABLE WITH THETA-E FOLDED OVER. LDN ACTUALLY PICKED UP A COUPLE LIGHTNING STRIKES OVER WESTERN LAKE ERIE AND NEAR TOLEDO. AM TEMPTED TO HOLD OFF ON MENTIONING THUNDER AS THE NAM WINDOW OF INSTABILITY IS PRETTY SHORT AND DIMINISHES AFTER 21Z. COULD SEE SOME HEAVY PRECIP RATES THOUGH...AS CAN BE INFERRED FROM SNOW THAT IS ALREADY ACCUMULATING ACROSS THE SOUTHERN CWA. THE FASTER TREND MAY LIMIT THE DURATION OF SNOWFALL ACROSS THE FAR SOUTHWEST...AS THE SYSTEM PULLS OUT FASTER. HOWEVER EXPECT THE SNOWFALL RATES THIS EVENING WITH WEAK STABILITY TO HELP US REALIZE THE WARNING CRITERIA SNOWFALL...AND THEREFORE WILL KEEP THE WARNING GOING. THE WESTWARD TREND WOULD ALLOW THE TROWAL TO SETUP FARTHER WEST AND NORTH ACROSS THE THUMB AND INTO NORTHERN LOWER. WILL BUMP SNOW ACCUMULATIONS UP A BIT OVER TOWARD BAY COUNTY. HOWEVER GIVEN THE SLOWER CHANGEOVER AND QUESTIONABLE ENHANCEMENT THAT FAR WEST WILL KEEP THEM IN AN ADVISORY. ELSEWHERE SNOW TOTAL STILL LOOK GOOD...WITH GREATEST AMOUNT ACROSS THE THUMB WITH SOME ENHANCEMENT IN THE NORTHERLY FLOW OFF HURON. WILL MENTION DEFINITE BLOWING SNOW ACROSS THE CWA TONIGHT AS FORECAST SOUNDINGS/TIME SECTIONS SHOW THE MIXED LAYER TAPPING INTO 40KTS A FEW THOUSAND FEET OFF THE SURFACE. GOOD CYCLONIC FLOW ON SUNDAY WITH TRAILING SHORTWAVE SWINGING THOUGH. LAKE EFFECT SETUP IS NOT ALL THAT IMPRESSIVE...ALTHOUGH SOME SYNOPTIC LIFT WITH RELATIVELY DEEP MOISTURE PRESENT COULD LEAD TO SOME ENHANCEMENT. THEREFORE WILL HOLD ONTO LIKELY POPS AT LEAST THROUGH THE MORNING DESPITE A QUICKER DEPARTURE TO THE SYSTEM. ADDED AREA OF BLOWING SNOW AS WELL WITH A STRONG GRADIENT AND CONTINUED DEEP MIXED LAYER. && .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY WEEKEND SURFACE LOW SLOWLY RETREATING NORTHEAST THROUGH QUEBEC THROUGH EARLY PART OF WEEK AS ASSOCIATED CYCLONIC FLOW BACK ACROSS THE FORECAST AREA AND EASTERN GREAT LAKES REGION SLOWLY WANES. AT THE SAME TIME...THE CLOSED STACKED LOW ALOFT VERY SLOWLY RETREATING NORTH/NORTHEAST. AFTER MODEST DEEPER MOISTURE WANES SUNDAY NIGHT...ESPECIALLY SOUTH...THIS DEEPER MOISTURE RATHER MEAGER THROUGH EARLY PART OF WEEK. LOWER LEVEL RELATIVE HUMIDITIES...ON THE OTHER HAND...REMAIN GENERALLY HIGH THROUGH EARLY WEEK. DYNAMICS SLIGHT AT BEST FROM TIME TO TIME THROUGH EARLY WEEK...INCLUDING LOW TO MID LEVEL QVECTOR CONVERGENCE...SURFACE CONVERGENCE AND OMEGA LIFT. QPF FIELDS ALSO VERY LIGHT...AND NAM ESSENTIALLY EVEN DRY THROUGH TUESDAY. GFS MODEL SOUNDINGS SHOW BETTER LOW LEVEL MOISTURE THAN NAM... TAPPING COLDER THAN MINUS 10C TEMPERATURES FOR ICE NUCLEI...AND WITH NEARLY DRY ADIABATIC LOW LEVEL LAPSE RATES MUCH OF THE TIME WITH WEST TO NORTHWEST FLOW...HAVE MENTIONED AT LEAST FLURRY CHANCES THROUGH EARLY WEEK. DURING THE MID WEEK PERIOD INTO THE WEEKEND... MODELS SHOW SOME CONSENSUS TOWARD SURFACE RIDGING OVERHEAD WEDNESDAY...THEN CONSIDERABLE TIMING/DETAIL DIFFERENCES AMONG MODELS AS TO BRINGING OF CLIPPER ON DOWN INTO LAKES REGION...WHICH WHEN THIS DOES HAPPEN WILL BE ACCOMPANIED BY A RESURGENCE OF COLD ARCTIC AIR LATE NEXT WEEK. AT 500 MB...CONSIDERABLE DETAIL DIFFERENCES AMONG MODELS ESPECIALLY WITH RESPECT TO TIMING AND PLACEMENT OF INDIVIDUAL SHORTWAVE TROUGH IMPULSES...BUT MAIN IDEA IS FOR LOWERING HEIGHTS LATTER PART OF WEEK...AND WITH AVAILABLE MODELS SHOWING IMPROVED MOISTURE...AMIDST OVERALL WESTERN RIDGE/EASTERN TROUGH SCENARIO PERSISTING...AND WITH BROAD TROUGH PERSISTING INTO THE WEEKEND. AFTER FLURRY CHANCES MENTIONED WEDNESDAY...THE PREVIOUS FORECAST FOR CHANCE OF SNOW SHOWERS THEREAFTER IS HARD TO ARGUE WITH. && .AVIATION...ISSUED 1236 PM EST SAT PRECIP RIGHT ON THE VERGE OF CHANGING OVER TO SNOW. WHILE SURFACE TEMPERATURES ARE GENERALLY 36-37F WITH DEWPOINTS 34-35F...15Z/16Z TAMDAR SOUNDINGS SHOW FREEZING LEVELS NEAR OR BELOW 1KFT AGL. DTW REPORTED A MIX RAIN/SNOW AT 17Z...WITH A SIMILAR TREND EXPECTED ELSEWHERE OVER THE NEXT TWO HOURS. RAIN WILL BE PREDOMINATE INITIALLY...BUT WITH A QUICK TRANSITION OVER TO SNOW EXPECTED FROM SOUTH TO NORTH GIVEN FREEZING LEVEL DEPICTION AND EXPECTED PRECIP INTENSITY. KEPT SIMILAR TIMING FOR MODERATE SNOW LATE THIS AFTERNOON AT FNT/DTW/DET...BUT DELAYED THE STRONGER WINDS UNTIL LATER THIS EVENING. ALSO GIVEN THE SOMEWHAT WESTWARD TRACK NOTED IN THE UPDATE SECTION...BROUGHT IN LOWER VISIBILITIES AT MBS AS WELL. PRETTY WIDESPREAD IFR/LIFR CIGS FROM WESTERN LOWER INTO THE THUMB...WHILE THERE HAVE BEEN A FEW MVFR REPORTS FROM THE SOUTHEAST CWA INTO ONTARIO/OHIO. IFR/LIFR CIGS TO CONTINUE THROUGH THE NIGHT... IMPROVING TO MVFR DURING THE MORNING ON SUNDAY. SLOWLY BROUGHT UP VISIBILITIES LATE TONIGHT INTO SUNDAY AS WELL. HOWEVER HELD ONTO SOME RESTRICTIONS AND A MENTION OF BLOWING SNOW WITH WINDS STILL 20G30KTS. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WINTER STORM WARNING...MIZ049-MIZ054-MIZ055-MIZ061-MIZ062-MIZ063- MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-MIZ082-MIZ083...UNTIL NOON SUNDAY. SNOW AND BLOWING SNOW ADVISORY...MIZ047-MIZ048-MIZ053-MIZ060... UNTIL NOON SUNDAY. LAKE HURON...GALE WARNING...NEARSHORE AND OPEN WATERS FROM PORT AUSTIN TO PORT HURON INCLUDING SAGINAW BAY...UNTIL 1 AM MONDAY. LAKE ST CLAIR...GALE WARNING...UNTIL 1 AM MONDAY. MI WATERS OF LAKE ERIE...GALE WARNING...UNTIL 1 AM MONDAY. && $$ SHORT TERM...BRAVENDER LONG TERM....DWD AVIATION...BRAVENDER YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 355 PM EST SAT FEB 4 2006 .DISCUSSION... MAIN FORECAST CONCERN IS SNOWFALL AMOUNTS AND HEADLINES FOR THE SHORT-TERM. CURRENT WEATHER...20Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED AN UPPER LEVEL TROUGH COVERING THE ENTIRE MISSISSIPPI VALLEY WITH RIDGING OVER THE INTERMOUNTAIN WEST AND IN THE NORTHEAST. A SHRTWV CAN BE SEEN ROTATING NE THROUGH THE GREAT SMOKY MOUNTAINS AREA AND A 993MB LOW WAS OBSERVED AT THE SURFACE IN FAR SE OHIO NEAR THE TIP OF THE SHRTWV. THIS LOW IS ALSO LOCATED UNDER A BROAD 120-140KT JET THAT EXTENDING FROM THE FLORIDA PANHANDLE INTO MAINE THAT WAS SEEN ON THE 12Z RAOBS. A NICE WARM CONVEYOR AND COLD CONVEYOR BELT STRUCTURE CAN BE SEEN AROUND THE SURFACE LOW WITH THE COLD CONVEYOR BELT IMPACTING LOWER MICHIGAN WITH SOME LIGHT RAIN...WHICH IS NOW CHANGING OVER TO SNOW. SOME OF THE BELT EVEN EXTENDS INTO THE EAST HALF OF UPPER MICHIGAN WHERE THE RADAR HERE SHOWS SOME LIGHT LAKE EFFECT SNOW FROM MARQUETTE/GWINN EASTWARD TO GRAND MARAIS. VISIBLE SATELLITE IMAGERY AND SURFACE OBS ALSO SHOW LAKE EFFECT SNOWS IMPACTING WESTERN UPPER MICHIGAN INTO NW WISCONSIN. CLEAR SKIES THEN EXIST ACROSS MUCH OF MINNESOTA UNDER A 1023MB RIDGE OF HIGH PRESSURE. THIS AIRMASS IS QUITE DRY AS DEWPOINTS THIS MORNING HAVE BEEN NEAR -10F. 12Z INL SOUNDING MODIFIED FOR THE AIR MOVING ACROSS WESTERN LAKE SUPERIOR STILL YIELDS AN INVERSION AROUND 900MB BUT QUITE A BIT IN THE WAY OF DRY AIR BELOW IT. HIGH CLOUDS ARE MOVING ACROSS THE PLAINS ON THE EAST SIDE OF THE INTERMOUNTAIN WEST RIDGE. THESE HIGH CLOUDS ARE COMING OFF THE PACIFIC...ASSOCIATED WITH A SIGNIFICANT TROUGH MOVING THROUGH THE PACIFIC NORTHWEST AND BRITISH COLUMBIA. FREQUENT LIGHTNING STRIKES AND PLENTY OF WIND HAVE OCCURRED WITH THIS TROUGH. TONIGHT...SHRTWV OVER THE GREAT SMOKY MOUNTAINS WILL CONTINUE HEADING UP TO THE N AND THEN NW AS IT BUILDS MORE RIDGING OVER THE NORTHEAST U.S.. THE RESULT OF THIS SHRTWV MOVEMENT AND INCREASING BAROCLINICITY FROM THE EXTRA RIDGING WILL BE TO STRENGTHEN THE SURFACE LOW. BY 12Z...THE NAM/GFS/UKMET/ECMWF SHOW A 980MB LOW NEAR THE SE END OF GEORGIAN BAY. UPPER MICHIGAN WILL REMAIN IN CYCLONIC FLOW AROUND THE LOW...HOWEVER THE DEEPEST MOISTURE IS PROGGED TO REMAIN OVER THE EASTERN HALF. WINDS WILL ALSO TURN MORE NORTHEASTERLY...FAVORING HEAVIER SNOW POSSIBILITIES TO SHIFT INTO THE HIGHER TERRAIN OF MARQUETTE AND WESTERN ALGER COUNTIES. HAVE MAINTAINED ADVISORIES FOR THESE COUNTIES AND FOLLOWED A 20 TO 1 RATIO WITH QPF SIMILAR TO THAT OF OUR LOCAL WRF RUN...WHICH HAS BEEN DOING WELL SO FAR TODAY WITH QPF. FOR THE WEST...ALTHOUGH THE LAKE EFFECT MAY SPARK UP SOME TONIGHT WITH THE DECREASE IN BOUNDARY LAYER MIXING FROM DIURNAL HEATING...THE LACK OF DEEP MOISTURE ALONG WITH THE MORE NORTHEASTERLY FLOW WILL HOLD DOWN SNOW AMOUNTS. WITH SNOW AMOUNTS SINCE 8 PM LAST NIGHT AT MOST OF 6 INCHES IN FAR WESTERN GOGEBIC COUNTY PER STATE POLICE...WHICH IS NEARLY TWICE BELOW WHAT IS NEEDED FOR A WARNING...HAVE DROPPED THAT WARNING ALONG WITH ALL THE OTHER ADVISORIES. CLOUDS WILL HOLD TEMPERATURES UP TONIGHT...SO EXPECT A SLOW FALL IN READINGS. SUNDAY...SHRTWV IS PROGGED TO CLOSE OFF INTO AN UPPER LOW IN THE MORNING...THEN BOTH THE SURFACE AND UPPER LOWS SHIFT TO NEAR OTTAWA BY 00Z. AS THE SYSTEM HEADS OUT...MUCH OF THE DEEPER MOISTURE WILL LEAVE WITH IT. THE COMBINATION OF THE LOSS OF MOISTURE AND THE DIURNAL CYCLE SHOULD KEEP AMOUNTS DOWN TO NO MORE THAN 3 INCHES. WINDS TURNING BACK TO THE NW WILL FAVOR THIS MAX AREA TO BE EAST OF MARQUETTE WHERE THE LONGEST FETCH OF LAKE MOISTENING EXISTS. INTERIOR SECTIONS SHOULD STAY GENERALLY DRY WITH PERHAPS A FEW FLURRIES AS LOW LEVEL MOISTURE HANGS AROUND. READINGS WILL BE SIMILAR TO TODAY\S SINCE THERE IS LITTLE VERY IF ANY CHANGE IN THE PATTERN PROGGED. THE EXCEPTION IS FOR NEWBERRY SINCE THEY ARE RELATIVELY WARM TODAY. HAVE BLOWING SNOW FOR BOTH TONIGHT AND SUNDAY AS WINDS BECOME GUSTY WITH THE DEEPENING LOW. GALE WARNINGS ARE IN EFFECT TOO FOR LAKE SUPERIOR AS 950MB WINDS INCREASE TO NEAR 40 KT BY SUNDAY MORNING. SUNDAY NIGHT THROUGH MONDAY NIGHT...VERY LITTLE CHANGE IN THE PATTERN IS PROGGED AS THE UPPER LOW BECOMES VERY SLOW TO MOVE OUT. AS A RESULT...LIGHT LAKE EFFECT SNOWS WILL LIKELY CONTINUE WITH FLURRIES OR NO PRECIPITATION IN THE SOUTHERN U.P.. THE LARGEST ACCUMULATIONS...ALBEIT NO MORE THAN 3 INCHES IN EACH 12 HOUR PERIOD...WILL REMAIN TO BE LOCATED IN THE EASTERN U.P. WHERE THEY ARE CLOSEST TO SHRTWV/S ROTATING AROUND THE UPPER LOW. INTERIOR SECTIONS MAY IN FACT PARTIALLY CLEAR OUT TOO THROUGH THIS PERIOD...AND WITH 850MB TEMPS IN THE TEENS BELOW ZERO...WOULD NOT BE SURPRISED FOR A FEW SITES TO GET AROUND ZERO FOR LOWS. 06Z MAV COOP GUIDANCE EVEN SHOWED A FEW OF THE TYPICAL COLD SITES DROPPING TO A FEW DEGREES BELOW ZERO MONDAY NIGHT. LITTLE CHANGE FOR TEMPS ON MONDAY WITH THE SAME AIRMASS OVER THE CWA AS ON SUNDAY. TUESDAY...GFS/ECMWF/UKMET ALL SHOW THE UPPER LOW LIFTING OUT THROUGH QUEBEC...WHICH ALLOWS HEIGHTS TO RISE OVER UPPER MICHIGAN. HOWEVER...LAKE INDUCED TROUGHING WILL CONTINUE AS 850MB TEMPS GRADUALLY WARM INTO THE SINGLE DIGITS ABOVE ZERO. SO THE LAKE EFFECT SNOW WILL CONTINUE...BUT AGAIN ON THE LIGHT VARIETY WITH EVEN DRIER AIR GETTING ADVECTED INTO THE CWA. WITH THE SLIGHT WARMING AT 850MB...SHOULD SEE A FEW MORE DEGREES ADDED ONTO MONDAY\S HIGHS. EXTENDED (WEDNESDAY THROUGH SATURDAY)...PATTERN SHIFT TOWARDS A POSITIVE PNA PATTERN CONTINUES TO BE ADVERTISED...MEANING A CHANGE TOWARDS COLDER WEATHER IS LIKELY. THE SYSTEM THAT IS THE MAIN CAUSE FOR THE CHANGE COMES OFF THE NE PACIFIC ON TUESDAY...THEN MOVES INTO CENTRAL CANADA ON WEDNESDAY. UPPER MICHIGAN AT THIS POINT WILL STILL BE UNDER THE INFLUENCE OF HIGH PRESSURE OVER THE OHIO VALLEY...KEEPING WINDS FROM THE WEST-SOUTHWEST AND ANY LES PUSHED INTO ONTARIO. ANY ISENTROPIC LIFT/WARM ADVECTION SNOW ALSO LOOKS LIKE IT WILL BE HELD OVER MANITOBA AND THE EASTERN DAKOTAS PER 00Z ECMWF/UKMET/CANADIAN. 00Z/06Z GFS APPEAR TO BE TOO FAST WITH THE SYSTEM. ALL MODELS INDICATE RIDGING BEING BUILT UP IN WESTERN CANADA WEDNESDAY NIGHT AND THURSDAY...CAUSING AN UPPER LEVEL TROUGH TO DEVELOP IN CENTRAL CANADA. THIS ALLOWS FOR COLD AIR TO START DROPPING SOUTH...INTENSIFYING THE CLIPPER SYSTEM. 00Z ECMWF/UKMET/CANADIAN SHOW THE LOW CENTER DROPPING INTO NORTH CENTRAL ONTARIO BY 00Z FRI WITH A PRESSURE AROUND 989MB. GIVEN THE PRESSURE...WOULD EXPECT THAT WEDNESDAY NIGHT AND THURSDAY WILL BE QUITE BREEZY...ALONG WITH SOME WARM ADVECTION SNOWS MOVING ACROSS THE U.P.. ON FRIDAY...A REX BLOCK FORMS IN THE WESTERN NORTH AMERICA WITH RIDGING FROM THE EAST PACIFIC INTO THE WESTERN U.S./CANADA AND AN UPPER LOW TRAPPED AROUND BAJA CALIFORNIA. WITH A REX BLOCK IN THE WEST...THIS FAVORS AN UPPER TROUGH IN THE UPPER MISSISSIPPI VALLEY AND THE GREAT LAKES...WHICH IS EXACTLY THE MODELS SHOW. AS A RESULT...THE ECMWF SHOWS 850MB TEMPS DROPPING TO -26C ACROSS NORTHERN MINNESOTA BY 00Z SAT WITH -20S C ENTERING WESTERN LAKE SUPERIOR. SO FOR FRIDAY AND SATURDAY...HAVE LAKE EFFECT SNOW CHANCES IN THE GRIDS. A COUPLE OF BELOW ZERO NIGHTS ARE LIKELY...ESPECIALLY IN THE INTERIOR AWAY FROM WHERE THE LES OCCURS. DESPITE THE VERY COLD AIR...WHICH RESULTS IN QUITE A BIT OF INSTABILITY OVER LAKE SUPERIOR...THE AIR WILL LIKELY BE DRY. THEREFORE WILL NOT MENTION ANYTHING ABOUT SIGNIFICANT LAKE EFFECT SNOW IN THE HWO. && .MQT WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST SUN MIZ005-006. GALE WARNING IN EFFECT EASTERN 2/3 OF LAKE SUPERIOR. $$ AJ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1236 PM EST SAT FEB 4 2006 .AVIATION... PRECIP RIGHT ON THE VERGE OF CHANGING OVER TO SNOW. WHILE SURFACE TEMPERATURES ARE GENERALLY 36-37F WITH DEWPOINTS 34-35F...15Z/16Z TAMDAR SOUNDINGS SHOW FREEZING LEVELS NEAR OR BELOW 1KFT AGL. DTW REPORTED A MIX RAIN/SNOW AT 17Z...WITH A SIMILAR TREND EXPECTED ELSEWHERE OVER THE NEXT TWO HOURS. RAIN WILL BE PREDOMINATE INITIALLY...BUT WITH A QUICK TRANSITION OVER TO SNOW EXPECTED FROM SOUTH TO NORTH GIVEN FREEZING LEVEL DEPICTION AND EXPECTED PRECIP INTENSITY. KEPT SIMILAR TIMING FOR MODERATE SNOW LATE THIS AFTERNOON AT FNT/DTW/DET...BUT DELAYED THE STRONGER WINDS UNTIL LATER THIS EVENING. ALSO GIVEN THE SOMEWHAT WESTWARD TRACK NOTED IN THE UPDATE SECTION...BROUGHT IN LOWER VISIBILITIES AT MBS AS WELL. PRETTY WIDESPREAD IFR/LIFR CIGS FROM WESTERN LOWER INTO THE THUMB...WHILE THERE HAVE BEEN A FEW MVFR REPORTS FROM THE SOUTHEAST CWA INTO ONTARIO/OHIO. IFR/LIFR CIGS TO CONTINUE THROUGH THE NIGHT... IMPROVING TO MVFR DURING THE MORNING ON SUNDAY. SLOWLY BROUGHT UP VISIBILITIES LATE TONIGHT INTO SUNDAY AS WELL. HOWEVER HELD ONTO SOME RESTRICTIONS AND A MENTION OF BLOWING SNOW WITH WINDS STILL 20G30KTS. && .UPDATE...1111 AM EST SAT FEB 4 2006 REGIONAL RADAR SHOW PRECIP SPREADING ACROSS SOUTHEAST LOWER...RAIN AT THIS POINT ACROSS THE CWA. HEAVIER BAND OF REFLECTIVITIES ACROSS THE FAR SOUTHEAST FROM PHN-DUH LEADING TO ADDITIONAL DYNAMIC COOLING...WITH SPOTTER REPORT OF RAIN/SNOW MIX IN FAR SOUTHEAST OAKLAND COUNTY. SURFACE ANALYSIS SHOWS THE LOW OVER NORTHWESTERN WEST VIRGINIA...WITH 3HR PRESSURE FALLS INCREASING ACROSS OHIO TO THE NORTH OF THE SYSTEM. THIS SUPPORTS A TURN MORE TO THE NORTH... WHICH WOULD BE EXPECTED AS THE UPPER SYSTEM TAKES ON MORE OF A NEGATIVE TILT. 12Z RUC INITIALIZED THE SURFACE POSITION BETTER... WITH THE NAM/WRF-XX A BIT FAR WEST. WHILE INITIALLY EAST...THE PRESSURE FALLS ACROSS CENTRAL OHIO DO SUPPORT THE RUC FORECAST WHICH TRACKS THE LOW ACROSS CENTRAL LAKE ERIE...OR FARTHER WEST THAN THE 12Z NAM/WRF-XX. GOOD +130KT 300MB JETLET EXTENDING INTO CENTRAL OHIO APPARENT IN 12Z RAOBS/ACARS DATA. STRONGER UPPER DIVERGENCE/PRESSURE FALLS WOULD SUPPORT THE MORE NORTHERLY TURN BY THE SURFACE LOW INDICATED BY THE RUC...ADDING SUPPORT FOR THE STRONG LIFT FROM THE IMPRESSIVE FRONTOGENESIS TO AFFECT AREAS FARTHER WEST INTO THE CWA BY LATE AFTERNOON. 14Z TAMDAR DESCENT SOUNDINGS INTO DTW FROM THE NORTHWEST SHOW FREEZING LEVELS HAVE DROPPED OVER THE PAST FEW HOURS AS COLD ADVECTION PICKS UP. 12Z RUC/NAM FORECAST SOUNDINGS ARE SIMILAR TO EARLIER RUNS...DROPPING THE ENTIRE COLUMN BELOW ZERO BY THIS EVENING. RUC FREEZING LEVEL FORECAST LOOKS TO LINE UP PRETTY WELL WITH LATEST SURFACE OBSERVATIONS OF SNOW ACROSS INDIANA INTO SOUTHWEST LOWER. TIMING THROUGH THE AFTERNOON SUPPORTS A MIX BY 18Z WITH ALL SNOW BY 21Z. OVERALL THE FORECAST LOOKS ON TRACK. WILL UPDATE TO FRESHEN THE WORDING AND TWEAK PRECIP TYPE TIMING...MAINLY TO ADD A LONGER PERIOD OF MIXED RAIN/SNOW ACROSS THE SAGINAW VALLEY. && .PREV DISCUSSION...ISSUED 347 AM EST SAT FEB 4 2006 SHORT TERM...TODAY AND TONIGHT A WINTER STORM WARNING WILL BE ISSUED FOR THE CURRENT WATCH AREA AND A SNOW AND BLOWING SNOW ADVISORY FOR THE TRI CITIES, BOTH HEADLINES THROUGH NOON SUNDAY. A FEW THINGS TO NOTE IN THE OBSERVATIONS EARLY THIS MORNING. THE FIRST IS THAT IT IS ALREADY RAINING AS FAR NORTH AS FORT WAYNE AND DEFIANCE. THE SECOND IS THAT LOW PRESSURE IS FILLING PRETTY QUICKLY OVER CENTRAL AND NORTHERN LOWER MICHIGAN. THIRD, IT JUST STARTED SNOWING IN EVANSVILLE AND INDY. THESE THINGS SUPPORT LEANING THE FORECAST TOWARD A COLDER SOLUTION AS WE HEAD THROUGH THE DAY. A LONGER DURATION OF PRECIPITATION INTO THE LOW LEVELS WILL LEAD TO GREATER WET BULB COOLING. THE SURFACE LOW OVER CENTRAL AND NORTHERN LOWER IS HOLDING BACK COLD SURFACE AIR AND ONCE THAT IS GONE THE COLD AIR WILL MAKE A STRONG PUSH INTO THE LOW LEVELS OVER SE MICHIGAN AS EVIDENCED BY OBS OF SNOW OVER INDIANA. PRECIPITATION WILL START OUT AS RAIN OVER THE WARNING AREA AND A MIX OF RAIN AND SNOW OVER THE ADVISORY AREA BUT CHANGE TO ALL SNOW BY MID AFTERNOON AND THEN CONTINUE THROUGH TONIGHT. THE GFS REMAINS THE MODEL OF CHOICE AS IT IS THE ONLY ONE HANDLING THE OBSERVED PRECIPITATION PATTERN OVER INDIANA. THIS FACT GIVES IT THE BEST CHANCE OF CORRECTLY SIMULATING THE LOW LEVEL THERMAL FIELDS SO IMPORTANT TO TIMING THE CHANGE OVER TO SNOW. IT KEEPS 850 MB WET BULB TEMPS BELOW ZERO THROUGH TODAY AND 1000-850 MB THICKNESS INDICATES A CHANGE OVER TO SNOW BY 3 PM AS VALUES FALL TO AROUND 1295 METERS BY 00Z THIS EVENING. EXPECT A COUPLE OF INCHES OF WET ACCUMULATION BY 7 PM AND THEN THINGS GO DOWN HILL FROM THERE. FOR TONIGHT, MODES OF FORCING RUN THE SPECTRUM WITH SUCH A DYNAMIC SYSTEM. WARM ADVECTION/THETA-E ADVECTION DURING TODAY WILL TRANSITION TO STRONG LIFT IN THE OCCLUSION ZONE OF THE SYSTEM WHICH WILL SET UP OVER SE MICHIGAN. 700 MB WINDS IN THE TROWAL WILL BE IN THE 30 TO 40 KNOT RANGE AND IN AN ENVIRONMENT OF INCREASINGLY LOW STABILITY. SPECIFIC HUMIDITY IN THE 3 TO 4 G/KG RANGE FOR 12 TO 15 HOURS SHOULD BRING ACCUMULATION OVER 6 INCHES IN WESTERN SECTIONS OF THE WARNING AREA AND CLOSE TO A FOOT IN THE THUMB WHERE LAKE ENHANCEMENT CAN BE EXPECTED AS 850 MB TEMPS APPROACH -10C OVERNIGHT. COUPLE THE HEAVY SNOW WITH 30 MPH WINDS FOR SIGNIFICANT BLOWING AND DRIFTING OVER ALL OF SE MICHIGAN AND NEAR BLIZZARD CONDITIONS IN THE THUMB, ESPECIALLY NEAR THE SHORELINE WITH 40 MPH WIND GUSTS POSSIBLE. EXPECT SHORELINE AREAS COULD BE UPGRADED TO A BLIZZARD WARNING WITH LATER FORECASTS FOR HEIGHTENED AWARENESS IN THE SHORT TERM. LONG TERM...SUNDAY THROUGH FRIDAY A RETURN TO WINTER INDEED WITH A POTENTIAL SHOT OF A STRONG CLIPPER SYSTEM FOR MID WEEK. VIGOROUS AND DEEP CYCLONE JUST EAST OF LAKE HURON SUNDAY MORNING WITH WRAP AROUND MOISTURE IN THE DEFORMATION AND POTENTIAL TROWAL AXIS ACROSS THE NORTHERN AND WEST PORTIONS OF THE CWA. SNOW INTENSITY WILL QUICKLY DECREASE FROM SOUTHWEST TO NORTHEAST...WITH THE EXCEPTION OF THE THUMB REGION AS COMBINATION OF LAKE ENHANCEMENT AND CLOSER PROXIMITY TO THIS STORM. HERE WE WILL ADD ON ANOTHER 1-2" WITH AN INCH OR LESS FOR THE REMAINDER OF THE CWA. NEEDLESS TO SAY...WINDS WILL BE STRONG ACROSS THE STATE WITH NEAR BLIZZARD CONDITIONS POSSIBLE AND WIND CHILLS AROUND 10 ABOVE ZERO AS MIXING MOMENTUM POINTS TOWARD MID 30KT GUSTS. AS SYSTEM FILLS AND BECOMES FURTHER REMOVED FROM THE STATE SUNDAY NIGHT...WE WILL SLOWLY SEE IMPROVEMENTS...BUT THE KEY WORD HERE IS SLOWLY. WITH COLD AND DEEP CYCLONIC FLOW ACROSS THE REGION...WE WILL HOLD ONTO THE MENTION OF SNOW SHOWERS ACROSS THE ENTIRE REGION. WILL HAVE TO MONITOR DEFORMATION AXIS ACROSS HURON COUNTY AS GFS/NAM SUGGEST IT WILL BE CLOSE...AND THIS WOULD ADD ONTO THE SNOWFALL ACCUMULATIONS. FURTHERMORE...RESIDUAL SHORT WAVE PULSES ROTATING AROUND THIS SYSTEM MAY ENHANCE SNOWFALL AS WELL. 850MB TEMPS DROP BACK WELL INTO THE NEGATIVE TEENS AND SURFACE REFLECTION WILL BE LOWS FALLING BACK TO AROUND 20F WITH WIND CHILLS INTO THE SINGLE DIGITS. THE REAL NEXT SHOT FOR SNOW AND ARCTIC AIR ARE STILL SCHEDULED FOR MID-LATE WEEK. THIS COULD BE QUITE A STRONG CLIPPER SYSTEM AS THE WATER VAPOR LOOP ACROSS THE WESTERN GULF OF ALASKA LOOKS QUITE POTENT AND TRENDS IN THE GFS/DGEX/ECMWF SUGGEST A ROBUST CLIPPER WITH 850MB TEMPS TAPPING INTO SUB -20C AIRMASS THAT DIVES SOUTH INTO THE NORTHERN PLAINS BY WEEKS END. WE WILL CONTINUE TO HIGHLIGHT THIS WITHIN THE HWO THIS MORNING. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WINTER STORM WARNING...MIZ049-MIZ054-MIZ055-MIZ061-MIZ062-MIZ063- MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-MIZ082-MIZ083...1 PM SATURDAY TO NOON SUNDAY. SNOW AND BLOWING SNOW ADVISORY...MIZ047-MIZ048-MIZ053-MIZ060... 1 PM SATURDAY TO NOON SUNDAY. LAKE HURON...GALE WARNING...NEARSHORE AND OPEN WATERS FROM PORT AUSTIN TO PORT HURON INCLUDING SAGINAW BAY...4 PM SATURDAY TO 1 AM MONDAY. LAKE ST CLAIR...GALE WARNING...4 PM SATURDAY TO 1 AM MONDAY. MI WATERS OF LAKE ERIE...GALE WARNING...4 PM SATURDAY TO 1 AM MONDAY. && $$ AVIATION.....BRAVENDER UPDATE.......BRAVENDER SHORT TERM...BT LONG TERM....BGM YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1120 AM EST SAT FEB 4 2006 .UPDATE... MAIN FCST CONCERNS THIS AFTERNOON ARE SN/LES TRENDS. WV IMAGERY...RUC ANALYSIS AND 12Z RAOBS INDICATED A MID/UPR LVL TROF FROM HUDSON BAY THROUGH WI TO THE LWR MS VALLEY. WHILE VERY POTENT SHRTWV REMAINS WELL TO THE S INTO ERN KY/TN A WEAKER SHRWV INTO ERN UPR MI AND ASSOCIATED MODEST 700-500 MB FGEN/DEFORMATION SUPPORTED A BAND OF SNOW ACRS MUCH OF CENTRL AND E UPR MI. WV/VIS IMAGERY SHOWED BACK EDGE OF DEEPER MOISTURE FROM N CNTRL LK SUPERIOR TO CMX-LNL. ALTHOUGH PLENTY OF COLD AIR WAS AVBL UPSTREAM FROM LK SUPERIOR...AIRMASS WAS VERY DRY WITH MAINLY CLEAR SKIES AND SFC DEWPOINTS AOB 0F. 12Z CYQT TAMDAR SNDG SHOWED -17C TEMP AT TOP OF STRONG INVERSION AT 925 MB(2.5K FT). OBS OVER THE WEST INDICATED VSBYS GENERALLY AROUND 2SM. RADAR TRENDS AND 12Z RUC/NAM SUGGEST THAT THE SHRTWV AND FORCING WILL GRADUALLY WEAKEN THIS AFTERNOON WITH THE AREA OF DEEPER MOISTURE MAKING LITTLE/NO FURTHER PROGRESS TO THE WEST. WHILE ADDITIONAL 950-850 MB SHOULD INCREASE INSTABILITY OVER THE WEST HLF THIS AFTERNOON...DIURNAL TRENDS AND BNDRY LYR DRYING UPSTREAM WILL BE LESS FAVORABLE. SO...EXPECT ONLY SLOW INCREASE IN LES RATES OVER THE WEST. EVEN THOUGH IT MAY BE A STRETCH TO REACH ADVY OR WARNING SNOWFALL AMOUNTS...WILL LEAVE HEADLINES IN PLACE FOR NOW AS AT LEAST LIGHT TO OCNLY MODERATE LES SHOULD PERSIST THROUGH TONIGHT. OVER THE E HLF...SYNOPTIC LIGHT SNOW WILL GRADUALLY DIMINISH BUT MAY PRODUCE ANOTHER INCH BY THIS EVENING. SINCE RADAR TRENDS AND SFC OBS INDICATE BAND OF MORE SIGNFICANT SNOW HAS LIFTED N OF DELTA COUNTY...ADVY WILL BE DROPPED. COMBINATION OF BEST UPWARD MOTION AND ONSHORE NRLY WINDS FOR LAKE ENHANCEMENT (KSAW TAMDAR SNDGS -11C AT 890 MB) SHOULD IMPACT MAINLY ALGER AND FAR E MARQUETTE COUNTY. THERE...ADDITIONAL AMOUNTS 2 TO 3 INCHES ARE POSSIBLE THIS AFTERNOON. && .PREV DISCUSSION...ISSUED 521 AM EST SAT FEB 4 2006 UPPER AIR PATTERN CONSISTS OF A 500 MB TROUGH AND CLOSED LOW OFF THE PACIFIC NW COAST...RIDGING ACROSS THE GREAT BASIN AND NORTHERN ROCKIES AND TROUGHING IN THE CENTRAL U.S. THERE ARE SHORTWAVES EMBEDDED IN THIS TROUGH WITH ONE OVER CENTRAL WI WHICH IS PUTTING OUT SOME SNOW ACROSS THE EASTERN HALF OF THE CWA LATE THIS EVENING. MORE SHORTWAVE ENERGY IS DIVING DOWN SOUTH NEAR LAKE WINNIPEG. BOTH SHORTWAVES SHOW UP AS DARKENING ON WATER VAPOR AND SOME CYCLONIC SPIN NOTED ON WATER VAPOR IN THOSE AREAS. 500 MB TROUGH AXIS IS ACROSS WRN LAKE SUPERIOR THIS EVENING AND IT SLOWLY PUSHES EAST TODAY. NAM FORMS A CLOSED 500 MB LOW BY 00Z TONIGHT OVER SW OHIO AND TAKES THIS LOW NE TONIGHT TO NEAR NIAGARA FALLS BY 12Z SUN AND THEN INTO QUEBEC WHERE IT SITS AND SPINS THROUGH 12Z TUE AND KEEPS THE CWA IN THE 500 MB TROUGH ON THE WESTERN SIDE. NAM SHOWS 850-500 MB Q-VECTOR CONVERGENCE OVER THE CWA TODAY WITH 1000-500 MB RH REMAINING ACROSS THE CWA WITH THE SHORTWAVE IN WI. BEST DYNAMICS PULL OFF TO THE EAST HALF OF CWA THIS AFTERNOON AND THEN PULL OUT OF CWA TONIGHT. NAM ALSO SHOWS SOME WEAK ISENTROPIC LIFT OVER THE ERN HALF OF THE CWA TODAY PM I280-I285K SURFACES WITH MOISTURE BELOW 700 MB. THIS LIFT PULLS OUT AFTER 00Z TONIGHT. GFS IS SIMILAR WITH ITS SOLUTION TO THE NAM AND ALSO SHOWS ISENTROPIC LIFT ON THE I280K-I290K SURFACE TODAY OVER THE EASTERN CWA...BUT SEEMS STRONGER ON ITS LIFT AND ALSO HAS SLIGHTLY DEEPER MOISTURE OVER THE EAST THAN THE NAM DOES. LOOKED AT 700-500MB LAPSE RATES AND THEY ARE STEEP. THE NAM PUTS THE AXIS OF STEEP LAPSE RATES OVER THE CENTRAL CWA TODAY WHILE THE GFS IS SLIGHTLY FURTHER WEST WITH STEEP LAPSE RATES OVER THE WESTERN HALF OF THE CWA. LAPSE RATES ARE FROM 6-7C/KM. GFS ALSO APPEARS TO HAVE INITIALIZED BETTER AT 850 MB TEMPERATURES THIS EVENING THAN THE NAM ACROSS CANADA AND WILL GO WITH THE COLDER 850 MB TEMPERATURES OF THE GFS. GFS KEEPS THE COLDEST 850 MB TEMPERATURES ACROSS THE WRN CWA WHICH HAS BEEN CONSISTENT WITH PREVIOUS MODEL RUNS. QUICK LOOK UPSTREAM SHOWS DRY AIR ACROSS ONTARIO WITH DEW POINTS BELOW ZERO AND THIS IS HEADED TOWARDS LAKE SUPERIOR AND ESPECIALLY ACROSS THE WEST. PROBLEM IS THAT THIS DRY AIR IS COMING IN...BUT 850 MB TEMPERATURES COOL OFF DURING THE DAY AND THE GFS SHOWS STEEP LAPSE RATES OVER THE AREA IN THE AFTERNOON. QUESTION IS IF THIS WILL BE ENOUGH TO HELP ENHANCE THE SNOWFALL...BUT THINK THE DRY AIR WILL BE THE MAIN PLAYER IN THIS FORECAST AND THIS WILL EAT INTO THE SNOWFALL TOTALS. WILL FORECAST THE LOW END OF A WARNING CRITERIA OF 10 INCHES ACROSS GOGEBIC COUNTY THROUGH TONIGHT FOR 24 HOURS TO ACCOUNT FOR THIS DRIER AIR. GFS AND NAM BOTH HAVE INVERSION HEIGHTS OF 3000 FEET OR SO WITH THE GFS SLIGHTLY HIGHER. IF THE DRY AIR GETS DISPLACED FURTHER WEST...THE 10 INCHES FOR THE WEST MIGHT BE THEN UNDERDONE...BUT DO NOT THINK THIS WILL HAPPEN. OTHER PROBLEM IS THE WI SHORTWAVE HAS PUSHED THE TIMING OF THE COLDER AIR ARRIVING FURTHER BACK AND THAT IS WHY THE LAKE EFFECT SNOW IN THE WEST HAD NOT STARTED UNTIL AROUND 4 AM THIS MORNING AS LAKE-850 MB DELTA-T TEMPERATURES WERE MARGINAL AROUND 13C ACROSS THE WESTERN LAKE. A QUICK LOOK AT KMQT RADAR SHOWS THE COLD AIR FINALLY STARTING TO ARRIVE AS KIWD...KCMX AND KASX FINALLY STARTED TO SNOW OR HAVE LOWER VISIBILITIES THAN BEFORE. AS THIS SHORTWAVE PULLS NORTHEAST...THIS WILL ALLOW THE COLD AIR TO KEEP COMING SOUTH. EXTENDED THE ADVISORY FOR DELTA COUNTY BASED ON DYNAMICS AND MOISTURE AND ISENTROPIC LIFT THROUGH TODAY AND THINK 2-3 INCHES IS NOT OUT OF THE QUESTION FOR THEM. FURTHER EAST FOR SCHOOLCRAFT COUNTY...THEY APPEAR TO BE ON THE EDGE OF SNOW AND THINK THEY WILL STAY UNDERNEATH CRITERIA AND WILL GO 1-2 INCHES THERE. FOR MENOMINEE AND DICKINSON COUNTIES...THE ADVISORY WILL BE ALLOWED TO EXPIRE AS THE SIGNIFICANT MOISTURE IS DEPARTING. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST EXCEPT TO CUT SNOWFALL TOTALS A BIT WITH THE DRIER AIR AND MARGINAL LAKE-850 DELTA-T TEMPERATURES OVER THE EAST. TEMPERATURES LOOKED PRETTY GOOD AND MADE A FEW MINOR TWEAKS HERE AND THERE. THE LAKE EFFECT EVENT CONTINUES TO LOOK LIKE A LONG LIVED EVENT. WOULD NOT BE SURPRISED TO SEE HEADLINES EXTENDED FURTHER ON IN TIME AND CHANGES IN HEADLINES IN LATER FORECAST SHIFTS. && .MQT WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST SUN MIZ005-006. LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST SUN MIZ001-003-004-084. LAKE EFFECT SNOW WARNING UNTIL 6 AM EST /5 AM CST/ SUN MIZ002-009. GALE WARNING IN EFFECT EASTERN 2/3 OF LAKE SUPERIOR. $$ JLB(UPDATE) MICHELS(PREV DISC) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1111 AM EST SAT FEB 4 2006 .UPDATE... REGIONAL RADAR SHOW PRECIP SPREADING ACROSS SOUTHEAST LOWER...RAIN AT THIS POINT ACROSS THE CWA. HEAVIER BAND OF REFLECTIVITIES ACROSS THE FAR SOUTHEAST FROM PHN-DUH LEADING TO ADDITIONAL DYNAMIC COOLING...WITH SPOTTER REPORT OF RAIN/SNOW MIX IN FAR SOUTHEAST OAKLAND COUNTY. SURFACE ANALYSIS SHOWS THE LOW OVER NORTHWESTERN WEST VIRGINIA...WITH 3HR PRESSURE FALLS INCREASING ACROSS OHIO TO THE NORTH OF THE SYSTEM. THIS SUPPORTS A TURN MORE TO THE NORTH... WHICH WOULD BE EXPECTED AS THE UPPER SYSTEM TAKES ON MORE OF A NEGATIVE TILT. 12Z RUC INITIALIZED THE SURFACE POSITION BETTER... WITH THE NAM/WRF-XX A BIT FAR WEST. WHILE INITIALLY EAST...THE PRESSURE FALLS ACROSS CENTRAL OHIO DO SUPPORT THE RUC FORECAST WHICH TRACKS THE LOW ACROSS CENTRAL LAKE ERIE...OR FARTHER WEST THAN THE 12Z NAM/WRF-XX. GOOD +130KT 300MB JETLET EXTENDING INTO CENTRAL OHIO APPARENT IN 12Z RAOBS/ACARS DATA. STRONGER UPPER DIVERGENCE/PRESSURE FALLS WOULD SUPPORT THE MORE NORTHERLY TURN BY THE SURFACE LOW INDICATED BY THE RUC...ADDING SUPPORT FOR THE STRONG LIFT FROM THE IMPRESSIVE FRONTOGENESIS TO AFFECT AREAS FARTHER WEST INTO THE CWA BY LATE AFTERNOON. 14Z TAMDAR DESCENT SOUNDINGS INTO DTW FROM THE NORTHWEST SHOW FREEZING LEVELS HAVE DROPPED OVER THE PAST FEW HOURS AS COLD ADVECTION PICKS UP. 12Z RUC/NAM FORECAST SOUNDINGS ARE SIMILAR TO EARLIER RUNS...DROPPING THE ENTIRE COLUMN BELOW ZERO BY THIS EVENING. RUC FREEZING LEVEL FORECAST LOOKS TO LINE UP PRETTY WELL WITH LATEST SURFACE OBSERVATIONS OF SNOW ACROSS INDIANA INTO SOUTHWEST LOWER. TIMING THROUGH THE AFTERNOON SUPPORTS A MIX BY 18Z WITH ALL SNOW BY 21Z. OVERALL THE FORECAST LOOKS ON TRACK. WILL UPDATE TO FRESHEN THE WORDING AND TWEAK PRECIP TYPE TIMING...MAINLY TO ADD A LONGER PERIOD OF MIXED RAIN/SNOW ACROSS THE SAGINAW VALLEY. && .AVIATION...651 AM EST SAT FEB 4 2006 AVIATION CONDITIONS WILL BE PLAGUED BY THE SNOW STORM EXPECTED TO IMPACT SE MICHIGAN TODAY AND TONIGHT. ONGOING IFR/LIFR FOG WILL GIVE WAY TO RAIN THIS MORNING AT DETROIT AND A MIX OF RAIN AND SNOW AT FLINT AND SAGINAW. THIS WILL BE FOLLOWED BY A RELATIVELY LONG PERIOD OF HEAVY SNOW AND BLOWING SNOW FROM LATE THIS AFTERNOON THROUGH LATE TONIGHT. LIFR CEILING AND VISIBILITY WILL BE WIDESPREAD ALONG WITH WIND GUSTS NEAR 30 KNOTS TO MAKE BLOWING AND DRIFTING SNOW A BIG PROBLEM. CONDITIONS WILL GRADUALLY IMPROVE TO MVFR DURING THE DAYLIGHT HOURS OF SUNDAY MORNING. THE LATEST SURFACE ANALYSIS AND RADAR DATA INDICATE THE LOW PRESSURE SYSTEM IS ON TRACK TO REACH CENTRAL LAKE ERIE BY 00Z THIS EVENING. PRECIPITATION IN ADVANCE OF THIS SYSTEM IS ALREADY INTO THE SAGINAW VALLEY IN THE FORM OF LIGHT RAIN. AT THE SAME TIME, RAIN IS CHANGING TO SNOW OVER INDIANA, WITH REPORTS OF SNOW NEARLY UP TO FORT WAYNE AT PRESS TIME. && .PREV DISCUSSION...ISSUED 347 AM EST SAT FEB 4 2006 SHORT TERM...TODAY AND TONIGHT A WINTER STORM WARNING WILL BE ISSUED FOR THE CURRENT WATCH AREA AND A SNOW AND BLOWING SNOW ADVISORY FOR THE TRI CITIES, BOTH HEADLINES THROUGH NOON SUNDAY. A FEW THINGS TO NOTE IN THE OBSERVATIONS EARLY THIS MORNING. THE FIRST IS THAT IT IS ALREADY RAINING AS FAR NORTH AS FORT WAYNE AND DEFIANCE. THE SECOND IS THAT LOW PRESSURE IS FILLING PRETTY QUICKLY OVER CENTRAL AND NORTHERN LOWER MICHIGAN. THIRD, IT JUST STARTED SNOWING IN EVANSVILLE AND INDY. THESE THINGS SUPPORT LEANING THE FORECAST TOWARD A COLDER SOLUTION AS WE HEAD THROUGH THE DAY. A LONGER DURATION OF PRECIPITATION INTO THE LOW LEVELS WILL LEAD TO GREATER WET BULB COOLING. THE SURFACE LOW OVER CENTRAL AND NORTHERN LOWER IS HOLDING BACK COLD SURFACE AIR AND ONCE THAT IS GONE THE COLD AIR WILL MAKE A STRONG PUSH INTO THE LOW LEVELS OVER SE MICHIGAN AS EVIDENCED BY OBS OF SNOW OVER INDIANA. PRECIPITATION WILL START OUT AS RAIN OVER THE WARNING AREA AND A MIX OF RAIN AND SNOW OVER THE ADVISORY AREA BUT CHANGE TO ALL SNOW BY MID AFTERNOON AND THEN CONTINUE THROUGH TONIGHT. THE GFS REMAINS THE MODEL OF CHOICE AS IT IS THE ONLY ONE HANDLING THE OBSERVED PRECIPITATION PATTERN OVER INDIANA. THIS FACT GIVES IT THE BEST CHANCE OF CORRECTLY SIMULATING THE LOW LEVEL THERMAL FIELDS SO IMPORTANT TO TIMING THE CHANGE OVER TO SNOW. IT KEEPS 850 MB WET BULB TEMPS BELOW ZERO THROUGH TODAY AND 1000-850 MB THICKNESS INDICATES A CHANGE OVER TO SNOW BY 3 PM AS VALUES FALL TO AROUND 1295 METERS BY 00Z THIS EVENING. EXPECT A COUPLE OF INCHES OF WET ACCUMULATION BY 7 PM AND THEN THINGS GO DOWN HILL FROM THERE. FOR TONIGHT, MODES OF FORCING RUN THE SPECTRUM WITH SUCH A DYNAMIC SYSTEM. WARM ADVECTION/THETA-E ADVECTION DURING TODAY WILL TRANSITION TO STRONG LIFT IN THE OCCLUSION ZONE OF THE SYSTEM WHICH WILL SET UP OVER SE MICHIGAN. 700 MB WINDS IN THE TROWAL WILL BE IN THE 30 TO 40 KNOT RANGE AND IN AN ENVIRONMENT OF INCREASINGLY LOW STABILITY. SPECIFIC HUMIDITY IN THE 3 TO 4 G/KG RANGE FOR 12 TO 15 HOURS SHOULD BRING ACCUMULATION OVER 6 INCHES IN WESTERN SECTIONS OF THE WARNING AREA AND CLOSE TO A FOOT IN THE THUMB WHERE LAKE ENHANCEMENT CAN BE EXPECTED AS 850 MB TEMPS APPROACH -10C OVERNIGHT. COUPLE THE HEAVY SNOW WITH 30 MPH WINDS FOR SIGNIFICANT BLOWING AND DRIFTING OVER ALL OF SE MICHIGAN AND NEAR BLIZZARD CONDITIONS IN THE THUMB, ESPECIALLY NEAR THE SHORELINE WITH 40 MPH WIND GUSTS POSSIBLE. EXPECT SHORELINE AREAS COULD BE UPGRADED TO A BLIZZARD WARNING WITH LATER FORECASTS FOR HEIGHTENED AWARENESS IN THE SHORT TERM. LONG TERM...SUNDAY THROUGH FRIDAY A RETURN TO WINTER INDEED WITH A POTENTIAL SHOT OF A STRONG CLIPPER SYSTEM FOR MID WEEK. VIGOROUS AND DEEP CYCLONE JUST EAST OF LAKE HURON SUNDAY MORNING WITH WRAP AROUND MOISTURE IN THE DEFORMATION AND POTENTIAL TROWAL AXIS ACROSS THE NORTHERN AND WEST PORTIONS OF THE CWA. SNOW INTENSITY WILL QUICKLY DECREASE FROM SOUTHWEST TO NORTHEAST...WITH THE EXCEPTION OF THE THUMB REGION AS COMBINATION OF LAKE ENHANCEMENT AND CLOSER PROXIMITY TO THIS STORM. HERE WE WILL ADD ON ANOTHER 1-2" WITH AN INCH OR LESS FOR THE REMAINDER OF THE CWA. NEEDLESS TO SAY...WINDS WILL BE STRONG ACROSS THE STATE WITH NEAR BLIZZARD CONDITIONS POSSIBLE AND WIND CHILLS AROUND 10 ABOVE ZERO AS MIXING MOMENTUM POINTS TOWARD MID 30KT GUSTS. AS SYSTEM FILLS AND BECOMES FURTHER REMOVED FROM THE STATE SUNDAY NIGHT...WE WILL SLOWLY SEE IMPROVEMENTS...BUT THE KEY WORD HERE IS SLOWLY. WITH COLD AND DEEP CYCLONIC FLOW ACROSS THE REGION...WE WILL HOLD ONTO THE MENTION OF SNOW SHOWERS ACROSS THE ENTIRE REGION. WILL HAVE TO MONITOR DEFORMATION AXIS ACROSS HURON COUNTY AS GFS/NAM SUGGEST IT WILL BE CLOSE...AND THIS WOULD ADD ONTO THE SNOWFALL ACCUMULATIONS. FURTHERMORE...RESIDUAL SHORT WAVE PULSES ROTATING AROUND THIS SYSTEM MAY ENHANCE SNOWFALL AS WELL. 850MB TEMPS DROP BACK WELL INTO THE NEGATIVE TEENS AND SURFACE REFLECTION WILL BE LOWS FALLING BACK TO AROUND 20F WITH WIND CHILLS INTO THE SINGLE DIGITS. THE REAL NEXT SHOT FOR SNOW AND ARCTIC AIR ARE STILL SCHEDULED FOR MID-LATE WEEK. THIS COULD BE QUITE A STRONG CLIPPER SYSTEM AS THE WATER VAPOR LOOP ACROSS THE WESTERN GULF OF ALASKA LOOKS QUITE POTENT AND TRENDS IN THE GFS/DGEX/ECMWF SUGGEST A ROBUST CLIPPER WITH 850MB TEMPS TAPPING INTO SUB -20C AIRMASS THAT DIVES SOUTH INTO THE NORTHERN PLAINS BY WEEKS END. WE WILL CONTINUE TO HIGHLIGHT THIS WITHIN THE HWO THIS MORNING. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WINTER STORM WARNING...MIZ049-MIZ054-MIZ055-MIZ061-MIZ062-MIZ063- MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-MIZ082-MIZ083...1 PM SATURDAY TO NOON SUNDAY. SNOW AND BLOWING SNOW ADVISORY...MIZ047-MIZ048-MIZ053-MIZ060... 1 PM SATURDAY TO NOON SUNDAY. LAKE HURON...GALE WARNING...NEARSHORE AND OPEN WATERS FROM PORT AUSTIN TO PORT HURON INCLUDING SAGINAW BAY...4 PM SATURDAY TO 1 AM MONDAY. LAKE ST CLAIR...GALE WARNING...4 PM SATURDAY TO 1 AM MONDAY. MI WATERS OF LAKE ERIE...GALE WARNING...4 PM SATURDAY TO 1 AM MONDAY. && $$ UPDATE.......BRAVENDER AVIATION.....BT SHORT TERM...BT LONG TERM....BGM YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 1010 PM EST SAT FEB 4 2006 .SHORT TERM (TONIGHT - MONDAY)... SFC LOW CURRENTLY OVER EASTERN LAKE ERIE WITH SFC OCCLUSION STRETCHING ACROSS SOUTHWEST NEW YORK AND CENTRAL PENNSYLVANIA. ELEVATED CONVECTION ALONG FRONTAL BOUNDARY PRODUCING SOME THUNDERSTORM ACTIVITY. UPDATED ZONES/GRIDS TO PROLONG PERIOD OF RAIN FOR CENTRAL/EASTERN ZONES BASED ON FROPA AND LATEST RUC AND INCLUDED CHC OF TSRA FOR ALL BUT FAR NRN ZONES. NO OTHER CHANGES. RRM SFC LOW PRESSURE OVER THE CENTRAL OHIO VALLEY THIS AFTERNOON WILL TRACK NORTH TO CENTRAL LAKE ERIE TONIGHT. SHOT OF ISENTROPIC LIFT WITH A SSE LOW-LVL JET INCREASING TO GREATER THAN 50 KTS WILL BRING PERIODS OF RAIN TO THE ENTIRE FORECAST AREA THIS EVENING. STRONG INVERSION SHOULD KEEP DAMAGING WINDS ABOVE THE SFC... HOWEVER THERE IS SOME CONCERN FOR GUSTY WINDS OVER HIGHEST ELEVATIONS THIS EVENING AS THE LOW-LEVEL JET TRACKS OVER THE AREA. BUFKIT ETA FORECAST AT AVP SHOWS SI INDICES REACHING +1 THIS EVENING... SO AN ELEVATED RUMBLE OF THUNDER IS ALSO NOT OUT OF THE QUESTION FOR NORTHEAST PA... BUT FEEL THAT CHC'S ARE LOW ENOUGH TO LEAVE OUT OF THE FORECAST. RADAR MOSAICS ARE SHOWING SOME MODERATE RAINS OVER SE PA MOVING NORTH. HOURLY RAINFALL WITH THAT AREA IN THE DC/BWI AREA THIS AFTERNOON WAS MOSTLY 0.1 TO 0.2 INCHES PER HOUR. FFG GUIDANCE IN OUR AREA IS WELL OVER AN INCH IN 3 HOURS SO NOT EXPECTING ANY HYDRO CONCERNS WHEN THIS BATCH OF RAIN MOVES THROUGH. MODEL QPF'S REMAIN CONSISTENT IN THE 0.25 TO 0.50 INCH RANGE FOR MOST OF THE AREA... AND THAT SEEMS REASONABLE GIVEN THAT THIS WILL BE A FAIRLY QUICK SHOT OF RAIN... WITH THE DRY SLOT SWEEPING IN FROM SOUTH TO NORTH LATER THIS EVENING AND OVERNIGHT. RAIN DIMINISHES TO SCT SHOWERS LATER TONIGHT AS THE DRY SLOT SWEEPS IN FROM THE SOUTH. ENOUGH COLD AIR COULD GET INTO THE SW TO ALLOW FOR SCT RAIN OR SNOW SHOWERS AFTER MIDNIGHT... BUT SIGNIFICANT PRECIPITATION WILL BE OVER BY THEN. ATM CONTINUES TO COOL ON SUNDAY AS SOME LOW-LVL SYNOPTIC SCALE MOISTURE SWEEPS ACROSS THE AREA IN ASSOCIATION WITH THE UPPER LOW. THAT WILL BE ENOUGH FOR SCT LIGHT SNOW SHOWERS... ESPECIALLY SUNDAY AFTERNOON AND SUNDAY EVENING ACROSS UPSTATE NY... BUT ANY ACCUMULATIONS WILL BE LESS THAN AN INCH. EXPECT SOME GUSTY WEST TO SOUTHWEST WINDS ON SUNDAY AS THE DEEP SURFACE LOW MOVES SLOWLY NORTH ACROSS EASTERN CANADA. MODEL WIND PROFILES BENEATH THE SUBSIDENCE INVERSION SUNDAY AFTERNOON INDICATE THAT GUSTS WILL REMAIN BELOW ADVISORY CRITERIA... MAINLY IN THE 30 TO 35 MPH RANGE. ATM WILL BE COLD ENOUGH FOR LAKE EFFECT SNOW BY SUNDAY NIGHT. NAM BUFKIT PROFILES PLUS SUNY BROCKPORT MM5 FORECASTS INDICATE THAT THE SNOW BAND EAST OF LAKE ONTARIO WILL INITIALLY BE NORTH OF OUR CWA SUNDAY EVENING... BUT MAY DROP SOUTH TO NORTHERN ONEIDA COUNTY LATE SUNDAY NIGHT AND MONDAY. THIS COULD BE A MAJOR EVENT WITH SUFFICIENTLY COLD AIR... PLENTY OF MOISTURE IN THE LOWEST 200 MB OF THE ATM... AND A DEEP CRYSTAL GROWTH AREA. MAIN CONCERN FOR OUR AREA WILL BE EXACT LOCATION OF THE BAND... WITH SOME CONCERN THAT THE MODELS MAY BE UNDERDOING THE AMOUNT OF LAKE TROUGHING... WHICH WOULD ALLOW FOR MORE SW FLOW EAST OF THE LAKES AND COULD RESULT IN THE BAND BEING JUST NORTH OF ONEIDA COUNTY. KEEPING IN MIND THIS UNCERTAINTY... BUT GIVEN THAT THIS COULD BE A MAJOR EVENT... WE HAVE GONE WITH A LAKE EFFECT SNOW WATCH FOR LATE SUNDAY NIGHT THROUGH MONDAY. - MSE && .AVIATION (05/00Z - 06/00Z)... ALL TERMINALS WILL SEE MVFR CIGS THIS EVENING...AS SHRA CONTINUE TO DEVELOP IN WARM SECTOR OF SYSTEM BOMBING OVER THE GREAT LAKES. CIGS WILL OCCNL DROP TO IFR AT TIMES...WITH VIS DROPPING TO MVFR OR IFR. WINDS WILL CONTINUE FROM THE E-SE THIS EVENING GUSTING TO 25KT AT TIMES. ONCE COLD FRONT PUSHES THROUGH LATE TONIGHT...SHRA WILL WIND DOWN...BUT CIGS WILL REMAIN MVFR...AND WINDS WILL BEGIN TO SHIFT TO SOUTH...AND MIGHT WEAKEN A BIT...BUT WILL INCREASE AGAIN AND SHIFT TO SW SUN MORNING...WITH GUSTS TO 30 KT POSSIBLE DURING THE DAY...ESPECIALLY AT KSYR. ALSO DURING SUNDAY MORNING...KSYR/KELM/KAVP CIGS SHOULD IMPROVE TO VFR...WITH MVFR ELSEWHERE. SCT SHSN WILL DEVELOP DURING THE AFTERNOON. -CEMPA && .LONG TERM (MONDAY NIGHT - SATURDAY)... THE PATTERN SHIFTS THIS WEEKEND TO ESTABLISH AN EASTERN TROF. NW FLOW AND LAKE EFFECT LOOKS CERTAIN MONDAY NIGHT CONTINUING INTO AT LEAST TUESDAY. WITH THE MODEL TREND TO SLOW DOWN THE SFC RIDGE FROM THE WEST...WINDS WILL REMAIN FAVORABLE INTO WEDNESDAY NOW. FOLLOWED HPC GUIDANCE CLOSELY FOR LONG RANGE DAYS 4 TO 8. NEXT LOW DIVES DOWN BACKSIDE OF TROF FROM SOUTH CENTRAL CANADA TO BE HERE FRIDAY. THIS WAS SLOWED DOWN ON MODELS ALSO. THIS WILL BE SLOW TO LEAVE AS SOME MODELS POINT TO COASTAL DEVELOPMENT ALONG FRONT FOR SATURDAY. WEATHER GRIDS MOSTLY SW- WITH A BREAK THU BETWEEN THE LES AND SYNOPTIC STORM. TEMPERATURES FALL TO ABOUT NORMAL FOR TIME OF YEAR FOR DAYS 3 TO 8. -TAC && .HYDROLOGY... TODAYS RUN OF THE RIVER MODELS DO NOT SHOW AS MUCH THREAT OF SIGNIFICANT RISES AS YESTERDAY. FRIDAYS RAIN CAUSED RIVERS TO RISE A FEW FEET IN THE LAST 24 HOURS. THE HEADWATERS HAVE CRESTED. TODAY AND TONIGHTS RAIN WILL BRING ANOTHER QUARTER TO HALF INCH AVERAGE. RENEWED RISES BUT WITHIN BANKFULL. EVEN DOUBLING THE RAINFALL WOULD ONLY CAUSE MINOR ISOLATED FLOODING PROBLEMS. WINDS AND DROPPING TEMPERATURES SUNDAY WILL HELP TO SHUT OFF THE RUNOFF. -TAC && .BGM WATCHES/WARNINGS/ADVISORIES... .NY...LAKE EFFECT SNOW WATCH FOR NORTHERN ONEIDA COUNTY LATE SUNDAY NIGHT THROUGH MONDAY. .PA...NONE. && $$ MSE ny AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE RALEIGH NC 1029 AM EST SAT FEB 4 2006 .SHORT TERM (REST OF TODAY)... LOW PRESSURE CENTER WAS LOCATED NEAR HTS WITH WARM FRONT NEAR THE NC/VA BORDER. DEW POINTS AROUND 60 WERE MOVING INTO THE SANDHILLS WITH DEW POINTS ELSEWHERE IN THE MID AND UPPER 50S. 850MB ANALYSIS OF 12Z DATA SHOWED 45KT WINDS AT CHS MOVING NORTH TOWARD NC WITH GOOD CONVERGENCE ALONG THE 850MB FRONT. INCREASING DIVERGENCE WAS EVIDENT TO THE SOUTHWEST OVER GEORGIA AND SC JUST EAST OF THE STRONGEST 500MB HEIGHT FALLS. RUC FORECAST FOR THE AFTERNOON IS IN LINE WITH CURRENT OBSERVATIONS IN THE SENSE THAT SURFACE DEW POINTS SHOULD BE AROUND 60 OR IN THE LOWER 60S IN THE EASTERN ZONES. DESPITE THE CLOUD COVER...TEMPERATURES WERE MOVING PAST THE MID 60S TOWARD THE COAST. SOME OF THIS WARMTH SHOULD ADVECT INTO THE SANDHILLS AND COASTAL PLAIN DURING THE AFTERNOON. MODIFIED 12Z GSO SOUNDING FOR HIGHS IN THE UPPER 60S AND DEW POINTS JUST ABOVE 60 YIELDS CAPE OF AROUND 1600J/KG AND LIFTED INDEX AS LOW AS -5C...GIVEN RUC FORECAST TEMPERATURES ALOFT BY 21Z OVER CENTRAL NC AND NOT USING THE COLDEST TEMPERATURES ALOFT WHICH WILL BE MOVING INTO FAR WESTERN ZONES LATE IN THE DAY WITH THE APPROACH OF DRIER AIR. MSAS ALREADY SHOWS LIFTED INDICES AROUND -2 IN THE SANDHILLS. WITH NOSE OF MID AND UPPER- LEVEL JET OVERHEAD LATE THIS AFTERNOON... SUFFICIENT DYNAMICS WILL BE PRESENT...AND GIVEN ENOUGH INSTABILITY...ISOLATED SEVERE IS POSSIBLE PARTICULARLY EASTERN ZONES WHERE CURRENT VISIBLE IMAGES SHOW LOW CLOUDS NOT TO BE QUITE AS THICK AND WHERE RICHEST THETA-E LIES ON MSAS AND AS FORECAST BY THE RUC. WILL ISSUE SPS TO MENTION THIS BY NOON. GUSTY WINDS STARTING TO DEVELOP OVER THE SANDHILLS AND COASTAL PLAINS AND THIS IS IN LINE WITH INCREASING 850MB WINDS MOVING INTO THE AREA WITH EVEN WEAK MIXING. ADDED BREEZY CONDITIONS AND A FEW GUSTS TO FORECAST AS A RESULT. DRIER AIR EXPECTED TO MOVE WEST- TO- EAST FAIRLY QUICKLY THIS AFTERNOON. FORECAST K INDICES DROP QUICKLY TO NEAR NEGATIVE VALUES LATE IN THE DAY. GRIDDED AND WORDED FORECASTS SHOW CHANCES FOR RAIN ENDING QUICKLY LATE IN THE DAY ESPECIALLY TOWARD THE TRIAD AND VUJ. THANKS TO ADJACENT OFFICES FOR COLLABORATION THIS MORNING. UPDATED GRIDDED AND WORDED FORECASTS ALREADY ISSUED. && .PREVIOUS DISCUSSION... (ISSUED 200 AM EST SAT FEB 4 2006) SHORT TERM (TODAY THROUGH SUNDAY)... ONCE AGAIN IT APPEARS THAT THE INFAMOUS "CAROLINA SPLIT" WILL RESULT IN SIGNIFICANTLY LESS QPF AND ACTIVITY ACROSS CENTRAL NC THAN PREVIOUSLY ANTICIPATED. ONSET OF PRECIPITATION HAS BEEN SIGNIFICANTLY DELAYED DUE TO THE PRESENCE OF A DEEP DRY AIRMASS (PER 00Z GSO RAOB)IN PLACE WITH SFC DEWPOINTS IN THE UPPER 40S TO LOWER 50S. THROUGH 12Z... THE BULK OF ISENTROPIC LIFT ASSOCIATED WITH 850 AND SFC WARM FRONT WILL GO TO MOISTEN...BEFORE ANY QPF REACHES THE GROUND. DEEP CONVECTION THAT IS CURRENTLY OVER THE FLORIDA KEYS AND SOUTHEAST COAST IS BEING DRIVEN BY GOOD UPPER LEVEL DIFFLUENCE AND STRONG KINEMATICS FROM 140 KT JET OVER THE EASTERN GULF. HOWEVER...CENTRAL NC WILL REMAIN ON SUBSIDENCE SIDE OF THIS FEATURE AS IT LIFTS NORTHEAST LATER TODAY...WITH STRONG UPPER DIVERGENCE REMAINING OFFSHORE. MEANWHILE...SECONDARY AREA OF CONVECTION THAT IS CURRENTLY OVER EASTERN TN AND UPSTATE GEORGIA IS ASSOCIATED WITH STRONG LOW-LEVEL CONVERGENCE FROM DEEPENING SFC AND 850 LOW. THE LOW WILL TRACK WEST OF THE BLUE RIDGE WITH STRONG UPSLOPE COMPONENT ON THE LEE SIDE OF THE MOUNTAINS. HOWEVER...QPF WILL DECREASE EXPONENTIALLY FROM EAST OF THE MOUNTAINS. THIS APPARENT DISCONNECTION OF MOISTURE AND LIFT WILL ALSO REDUCE THE THREAT OF THUNDER AS WELL. 40KTS OF UNIDIRECTIONAL LOW-LEVEL SPEED SHEAR (40KTS) AND INSTABILITY SHOWERS FROM APPROACHING VORT. MAX WILL STILL SUPPORT WIDESPREAD SHOWERS WITH POPS REMAINING IN LIKELY CATEGORY. DRY SLOT WILL QUICKLY SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST AFTER 18Z WITH CLEAR SKIES BY MIDNIGHT ACROSS ALL OF THE CWA. COOL DOWN BEHIND SYSTEM FOR SUNDAY...HOWEVER CAA SEEMS RATHER MODEST WITH FLOW PREDOMINATELY WESTERLY. AS A RESULT...ADJUSTED TONIGHT'S LOW AND HIGHS SUNDAY UP A FEW DEGREES. LONG TERM (MONDAY NIGHT THROUGH FRIDAY)... NO CHANGES TO EXTENDED PERIOD. BROAD LONG WAVE TROUGH WILL REMAIN OVER THE EASTERN U.S. WITH FORECAST TIED TO THE TIMING OF SHORTWAVE TROUGHS TRANSLATING EAST THROUGH THE BASE OF LONG WAVE TROUGH. LATEST 00Z RUN OF THE GFS AND NAM HAVE TRENDED SLIGHTLY FASTER AND FARTHER SOUTH WITH MOISTURE/PRECIP FOR MONDAY AFTERNOON/NIGHT. SHOULD SEE BETTER RUN-TO RUN MODEL CONSISTENCY ONCE S/W ENERGY MOVES ONTO THE PACIFIC COAST. AVIATION... LOW PRESSURE CENTERED OVER SOUTH CENTRAL TENNESSEE WITH WARM FRONT EAST THROUGH SOUTH CAROLINA WILL MOVE NORTHEAST OVERNIGHT. UPPER LEVEL TROUGH WILL MOVE ACROSS REGION SATURDAY AFTERNOON. ANY PRECIPITATION THIS MORNING WILL BE WIDELY SCATTERED. HOWEVER DURING THE AFTERNOON THE CHANCE FOR RAIN WILL BE ENHANCED WITH THE MOVEMENT OF THE STRONG UPPER LEVEL SYSTEM. MVFR CEILINGS AND VSBYS THROUGH 11Z...EXCEPT IFR VSBYS RWI IN FOG. PATCHY LIGHT RAIN OVER THE TAF AREA. 11Z-20Z IFR TO MVFR CEILINGS AND MVFR VSBYS IN SCATTERED LIGHT RAIN AND FOG. AFTER 20Z VFR CEILINGS AND VSBYS. EAST TO SOUTHEAST WINDS AROUND 5 KTS THROUGH 18Z...THEN SOUTHERLY AROUND 10 KTS EXCEPT GUSTS TO 20 KTS THROUGH 00Z/05. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DJF nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 1255 PM EST SAT FEB 4 2006 .AVIATION (18Z-18Z)... WITH DETERIORATING CONDITIONS IN WINTER STORM...TAF SITES WILL HAVE IFR TO VFR CEILINGS AND VISIBILITIES INTO TONIGHT. THOUGH SNOW SHOWERS WILL CONTINUE AS LOW PRESSURE EXITS NORTHEAST...EXPECT IMPROVEMENT TO MVFR ON SUNDAY. GUSTY WINDS WILL PERSIST THROUGH THE FORECAST. && .SHORT TERM (TODAY)... UPDATED ZONES TO CLEAN UP WORDING. FORECAST STILL LOOKS GOOD WITH WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES STILL IN EFFECT. SNOW HAS BEGUN TO ACCUMULATE WITH UP TO AN 2 INCHES REPORTED NEAR CINCINNATI. EXPECT ACCUMULATING SNOW ACROSS ENTIRE ILN CWA BY LATE AFTERNOON. && .PREVIOUS DISCUSSION... (ISSUED 445 AM EST SAT FEB 4 2006) SHORT TERM (TODAY THROUGH TUESDAY)... SURFACE ANALYSIS SHOWS A DEEP SURFACE LOW OVER EASTERN KENTUCKY. KILN RADAR SHOWS RAIN HAS SPREAD ACROSS MUCH OF FORECAST AREA...WITH CENTRAL OHIO STILL REMAINING DRY AT THEM MOMENT. NAM AND GFS ARE IN PRETTY GOOD AGREEMENT WITH TAKING SURFACE LOW INTO NORTHEAST OHIO BY THE END OF THE DAY. AS IT CONTINUES TO DEEPEN AND MOVE NORTH...THEN COLDER AIR WILL BE PULLED EASTWARD ACROSS FORECAST AREA. 03Z AND 06Z RUC ARE BOTH A GOOD BIT COOLER WITH THEIR LOWER LEVEL THICKNESSES THAN NAM AND GFS. IN FACT RUC SUGGESTS MUCH OF WESTERN FA SHOULD TURN TO SNOW AROUND 09Z. WILL GO WITH THE GFS LOW LEVEL THICKNESS AS IT IS A BIT SLOWER THAN NAM. THIS BRINGS SWITCHOVER TO SNOW THIS MORNING IN THE WESTERN HALF AND EARLY TO MID AFTERNOON IN THE WEST. STRATIFORM SNOW WILL TRANSITION INTO A SHOWERY NATURE OVERNIGHT. TIGHT CYCLONIC FLOW SOUTH OF THE LOW WILL CREATE LAKE ENHANCED SHOWERS. THESE SHOWERS WILL START OUT AFFECTING WHOLE CWA BUT BY AFTER MIDNIGHT SHOWER ACTIVITY WILL BE SLACKENING OFF ACROSS THE SOUTH. CYCLONIC FLOW CONTINUES INTO SUNDAY WITH SCATTERED SNOW SHOWERS. STORM TOTAL BY EARLY SUNDAY MORNING WILL RANGE FROM 4 TO 6 ACROSS THE NORTH TO 1 TO 2 ACROSS THE SOUTH. WEATHER PATTERN THEN TRANSITION FROM UPPER TROF INTO A MORE WESTERLY PATTERN...WHICH RESULTS IN A DRY FORECAST THROUGH TUESDAY. MAV TEMPS LOOK PRETTY GOOD. WILL ONLY MAKE MINOR TWEAKS. TIPTON && .LONG TERM (TUESDAY NIGHT THROUGH FRIDAY)... NO CHANGES WERE MADE IN THE EXTENDED...FOR THOUGHTS OF PREVIOUS FORECAST SEE BELOW. TIPTON && (ISSUED 353 PM EST FRI FEB 3 2006) LONG TERM (SUNDAY THROUGH FRIDAY)... MAIN SYSTEM PULLING OFF TO THE NORTHEAST ON SUNDAY BUT CYCLONIC LOW LEVEL FLOW WILL REMAIN ACROSS THE AREA THROUGH MUCH OF THE DAY WITH CONTINUED CAA. BETWEEN THIS AND POSSIBLE FETCH OFF OF LAKE MICHIGAN...THINK CHANCE POPS FOR SNOW SHOWERS REASONABLE ACROSS ENTIRE AREA. AS LOW LEVEL FLOW BACKS SLIGHTLY WITH A LITTLE BIT OF WAA DEVELOPING LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT...EXPECT ANY SNOW SHOWER ACTIVITY TO COME TO AN END. NEXT CONCERN IS CLIPPER SYSTEM DROPPING DOWN FROM THE NORTHWEST LATE SUNDAY NIGHT AND MONDAY. THE GFS REMAINS CONSIDERABLY FARTHER SOUTH THAN THE NAM WITH THIS SYSTEM AND BOTH HAVE TRENDED FARTHER SOUTH THAN THE 00Z RUNS. GIVEN TRENDS...WOULD NOT BE SURPRISED IF THE SYSTEM ENDS UP MISSING OUR AREA TO THE SOUTH BUT WILL HANG ON TO A TOKEN 20 POP FOR THE FAR SOUTH ON MONDAY JUST IN CASE. UPPER LEVEL TROF THEN FORECAST TO REMAIN IN PLACE ACROSS THE AREA THROUGH THE REMAINDER OF THE LONG TERM. HOWEVER...WEAK RIDGING AT THE SURFACE SHOULD PROVIDE FOR A COUPLE OF DRY DAYS BEFORE STRONGER SHORT WAVE ENERGY PIVOTS DOWN INTO THE TROUGH LATER IN THE WEEK....BRINGING A CHANCE OF SNOW SHOWERS THURSDAY AND FRIDAY. GENERAL NORTHWEST FLOW PATTERN SHOULD ALLOW FOR MORE SEASONABLE TEMPERATURES DURING THE EXTENDED PERIOD AND HAVE MAINLY GONE BELOW GUIDANCE VALUES FOR TEMPS. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...WINTER STORM WARNING FOR OHZ026-034-035-042>044-051>053-061- 062 FROM 10 AM SATURDAY TO 7 AM SUNDAY. ...WINTER STORM WARNING FOR OHZ045-046-054-055 FROM 1 PM SATURDAY TO 7 AM SUNDAY. ...WINTER WEATHER ADVISORY FOR OHZ060-070>072-077-078 FROM 10 AM SATURDAY TO 7 AM SUNDAY. ...WINTER WEATHER ADVISORY FOR OHZ063-064-073-079>082-088 FROM 1 PM SATURDAY TO 7 AM SUNDAY. ...WINTER WEATHER ADVISORY FOR OHZ056-065-074 FROM 4 PM SATURDAY TO 7 AM SUNDAY. KY...WINTER WEATHER ADVISORY FOR KYZ089>096 FROM 10 AM SATURDAY TO 7 AM SUNDAY. ...WINTER WEATHER ADVISORY FOR KYZ097>100 FROM 1 PM SATURDAY TO 7 AM SUNDAY. IN...WINTER WEATHER ADVISORY FOR INZ050-058-059-066-073>075-080 FROM 10 AM SATURDAY TO 7 AM SUNDAY. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 638 AM EST SAT FEB 4 2006 .AVIATION (12Z-12Z)... STRONG MID LVL FRONTOGENETICAL FORCING AND DEFORMATION HAVE CONTRIBUTED TO DVLPMNT OF WIDESPREAD AREA OF -RA ACRS TAFS THIS MRNG. SFC LO CONTINUES TO DEEPEN AS IT MOVES INTO SE KENTUCKY. TROF EXTNDG NORTH FROM SFC LO ACRS FCST AREA AND INTO SRN LWR MICHIGAN. PROXIMITY OF TROF HAS INCREASED SFC/BNDRY LYR CONV ACRS FCST AREA FURTHER ENHANCING PCPN. WEST OF TROF COLDER AIR HAS BEGUN TO FILTER IN...WITH PCPN HAVING NOW CHANGED TO ALL -SN ACRS MUCH OF CNTRL AND SRN INDIANA. 06Z RUC AND GFS SOLNS SEEM TO HAVE BEST HANDLE ON BNDRY LYR THICKNESSES. BOTH INDCG LWR LVLS SHOULD BE ABLE TO SUPPORT -SN AT KCVG/KLUK/KDAY BTWN 14-16Z...AND AT KILN/KCMH/KLCK BTWN 17-20Z. THE SWITCH TO -SN WILL RUN IN TANDEM WITH MID LVL DEFORMATION AXIS...WHICH WILL MAKE SLOW PROGRESS EAST ACRS FCST AREA THRU ERLY EVNG. THIS WOULD SUGGEST THERE WILL LIKELY BE A 1-3 HOUR PERIOD OF HEAVIER SNOW IMMEDIATELY AFTER THE CHANGE OVER. HAVE HIT CIGS/VSBYS HARDEST DURING MID/LATE AFTN DROPPING TO IFR/LIFR. SFC LO WILL TRACK THRU UPR OH RIVER VLY AND BE LOCATED OVER NE OHIO BY THIS EVNG. THE LO WILL CONTINUE TO STRENGTHEN THROUGHOUT THE DAY...WITH W/NW WINDS INCREASING ABV 15KTS THIS AFTN AND BECMG GUSTY. EXPECTING WET HEAVY SNOW INITIALLY...BUT AS TEMPS CONTINUE TO DROP LATE THIS AFTN AND EVNG...MUCH OF THE SNOW WILL BE BLOWN AROUND BY THE WINDS. AS SFC LO TRACKS NORTH INTO ONTARIO OVERNIGHT...BEST LIFT AND MID LVL DEFORMATION WILL MOVE OUT OF FCST AREA. SHOULD SEE A GRADUAL IMPROVEMENT TO MVFR CIGS/VSBYS LATE TONIGHT AS -SN BECOME MORE SCATTERED AND SHOWERY. RYAN && .PREVIOUS DISCUSSION... (ISSUED 445 AM EST SAT FEB 4 2006) SHORT TERM (TODAY THROUGH TUESDAY)... SURFACE ANALYSIS SHOWS A DEEP SURFACE LOW OVER EASTERN KENTUCKY. KILN RADAR SHOWS RAIN HAS SPREAD ACROSS MUCH OF FORECAST AREA...WITH CENTRAL OHIO STILL REMAINING DRY AT THEM MOMENT. NAM AND GFS ARE IN PRETTY GOOD AGREEMENT WITH TAKING SURFACE LOW INTO NORTHEAST OHIO BY THE END OF THE DAY. AS IT CONTINUES TO DEEPEN AND MOVE NORTH...THEN COLDER AIR WILL BE PULLED EASTWARD ACROSS FORECAST AREA. 03Z AND 06Z RUC ARE BOTH A GOOD BIT COOLER WITH THEIR LOWER LEVEL THICKNESSES THAN NAM AND GFS. IN FACT RUC SUGGESTS MUCH OF WESTERN FA SHOULD TURN TO SNOW AROUND 09Z. WILL GO WITH THE GFS LOW LEVEL THICKNESS AS IT IS A BIT SLOWER THAN NAM. THIS BRINGS SWITCHOVER TO SNOW THIS MORNING IN THE WESTERN HALF AND EARLY TO MID AFTERNOON IN THE WEST. STRATAFORM SNOW WILL TRANSITION INTO A SHOWERY NATURE OVERNIGHT. TIGHT CYCLONIC FLOW SOUTH OF THE LOW WILL CREATE LAKE ENHANCED SHOWERS. THESE SHOWERS WILL START OUT AFFECTING WHOLE CWA BUT BY AFTER MIDNIGHT SHOWER ACTIVITY WILL BE SLACKENING OFF ACROSS THE SOUTH. CYCLONIC FLOW CONTINUES INTO SUNDAY WITH SCATTERED SNOW SHOWERS. STORM TOTAL BY EARLY SUNDAY MORNING WILL RANGE FROM 4 TO 6 ACROSS THE NORTH TO 1 TO 2 ACROSS THE SOUTH. WEATHER PATTERN THEN TRANSITION FROM UPPER TROF INTO A MORE WESTERLY PATTERN...WHICH RESULTS IN A DRY FORECAST THROUGH TUESDAY. MAV TEMPS LOOK PRETTY GOOD. WILL ONLY MAKE MINOR TWEAKS. TIPTON && .LONG TERM (TUESDAY NIGHT THROUGH FRIDAY)... NO CHANGES WERE MADE IN THE EXTENDED...FOR THOUGHTS OF PREVIOUS FORECAST SEE BELOW. TIPTON && (ISSUED 353 PM EST FRI FEB 3 2006) LONG TERM (SUNDAY THROUGH FRIDAY)... MAIN SYSTEM PULLING OFF TO THE NORTHEAST ON SUNDAY BUT CYCLONIC LOW LEVEL FLOW WILL REMAIN ACROSS THE AREA THROUGH MUCH OF THE DAY WITH CONTINUED CAA. BETWEEN THIS AND POSSIBLE FETCH OFF OF LAKE MICHIGAN...THINK CHANCE POPS FOR SNOW SHOWERS REASONABLE ACROSS ENTIRE AREA. AS LOW LEVEL FLOW BACKS SLIGHTLY WITH A LITTLE BIT OF WAA DEVELOPING LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT...EXPECT ANY SNOW SHOWER ACTIVITY TO COME TO AN END. NEXT CONCERN IS CLIPPER SYSTEM DROPPING DOWN FROM THE NORTHWEST LATE SUNDAY NIGHT AND MONDAY. THE GFS REMAINS CONSIDERABLY FARTHER SOUTH THAN THE NAM WITH THIS SYSTEM AND BOTH HAVE TRENDED FARTHER SOUTH THAN THE 00Z RUNS. GIVEN TRENDS...WOULD NOT BE SURPRISED IF THE SYSTEM ENDS UP MISSING OUR AREA TO THE SOUTH BUT WILL HANG ON TO A TOKEN 20 POP FOR THE FAR SOUTH ON MONDAY JUST IN CASE. UPPER LEVEL TROF THEN FORECAST TO REMAIN IN PLACE ACROSS THE AREA THROUGH THE REMAINDER OF THE LONG TERM. HOWEVER...WEAK RIDGING AT THE SURFACE SHOULD PROVIDE FOR A COUPLE OF DRY DAYS BEFORE STRONGER SHORT WAVE ENERGY PIVOTS DOWN INTO THE TROUGH LATER IN THE WEEK....BRINGING A CHANCE OF SNOW SHOWERS THURSDAY AND FRIDAY. GENERAL NORTHWEST FLOW PATTERN SHOULD ALLOW FOR MORE SEASONABLE TEMPERATURES DURING THE EXTENDED PERIOD AND HAVE MAINLY GONE BELOW GUIDANCE VALUES FOR TEMPS. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...WINTER STORM WARNING FOR OHZ026-034-035-042>044-051>053-061- 062 FROM 10 AM SATURDAY TO 7 AM SUNDAY. ...WINTER STORM WARNING FOR OHZ045-046-054-055 FROM 1 PM SATURDAY TO 7 AM SUNDAY. ...WINTER WEATHER ADVISORY FOR OHZ060-070>072-077-078 FROM 10 AM SATURDAY TO 7 AM SUNDAY. ...WINTER WEATHER ADVISORY FOR OHZ063-064-073-079>082-088 FROM 1 PM SATURDAY TO 7 AM SUNDAY. ...WINTER WEATHER ADVISORY FOR OHZ056-065-074 FROM 4 PM SATURDAY TO 7 AM SUNDAY. KY...WINTER WEATHER ADVISORY FOR KYZ089>096 FROM 10 AM SATURDAY TO 7 AM SUNDAY. ...WINTER WEATHER ADVISORY FOR KYZ097>100 FROM 1 PM SATURDAY TO 7 AM SUNDAY. IN...WINTER WEATHER ADVISORY FOR INZ050-058-059-066-073>075-080 FROM 10 AM SATURDAY TO 7 AM SUNDAY. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1031 AM EST SAT FEB 4 2006 .SHORT TERM (REST OF TODAY)... THE MORNING UPDATE REMOVED FOG WORDING AS ALL LOCATIONS HAVE INCREASED TO 6SM OR BETTER. RAIN IS MOVING NORTH TO THE PA-MD BORDER AND WILL MOVE OVER ALL AREAS THROUGH THE AFTERNOON. CURRENT SURFACE ANALYSIS SHOWS THE LOW IN SOUTHWESTERN WV WHICH IS SLIGHTLY EAST OF THE GFS AND NAM FORECAST. THIS DIFFERENCE WILL NOT AFFECT THE CWA AS WE WILL BE IN THE WARM SECTOR WITH A RAIN EVENT FOR TODAY. LIFTED INDICES...CAPE AND CURRENT LIGHTNING STRIKES WOULD SUPPORT THE CHANCE FOR THUNDER IN THE SOUTHERN ZONES LATER TODAY. WILL LEAVE THE WATCH ALONE FOR NOW AWAITING NEWER MODEL RUNS. OUR CONCERNS ARE THAT THE FLOW MAY BE TOO WESTERLY TO TAP INTO GOOD LAKE MOISTURE BUT NOT CONVINCED AS OF YET. && .PREVIOUS DISCUSSION... (ISSUED 309 AM EST SAT FEB 4 2006) SHORT TERM (TODAY THROUGH TONIGHT)... SFC LOW TRACKING INTO SOUTHEAST KENTUCKY AT 0730Z. LARGE RAIN SHIELD EXTENDS SOUTHWEST TO NORTH OF THE SFC LOW...WITH A NARROWER BAND OF MODERATE RAIN AHEAD OF THE LOW OVER THE CENTRAL APPALACHIANS. BASED ON RADAR...ETA12 AND RUC TRENDS...PRETTY CONFIDENT THAT STEADY RAINFALL WILL HOLD OFF UNTIL AFT 15Z MOST SECTIONS. HEAVIEST PRECIPITATION WILL REMAIN WEST OF THE STORM TRACK...WITH HALF TO THREE QUARTER INCH AMOUNTS COMMON FROM THE LAURELS NNEWD ACROSS THE NORTHWEST AND NORTH CENTRAL MOUNTAINS. NEXT CONCERN IS TIMING OF CHANGEOVER. VERY STEEP LAPSE RATES WILL ACCOMPANY THE COLD FRONT AS IT CROSSES WESTERN AND CENTRAL PA BETWEEN 00 AND 06 UTC. WITH VERY STEEP MID LEVEL LAPSE RATES AND STRONG DYNAMIC COOLING...A SHARP CHANGEOVER APPEARS LIKELY AND COULD BE ACCOMPANIED BY THUNDER (SIMILAR TO AN EVENT FROM ONLY TWO WEEKS AGO). AFTER FROPA...IT APPEARS THAT CHANNELED NORTHWEST FLOW INTO THE LAUREL MOUNTAINS WILL BE THE MAIN SENSIBLE WEATHER THREAT TONIGHT THROUGH SUNDAY NIGHT WHERE CURRENT WINTER STORM WATCH REMAINS IN EFFECT. MID LEVEL LAPSE RATES WILL REMAIN STEEP OVERNIGHT INTO SUNDAY...SO SCENARIO IS A FAVORABLE SETUP FOR HEAVY OROGRAPHIC SNOWS IN CAMBRIA AND SOMERSET COUNTIES. LONG TERM (SUNDAY THROUGH FRIDAY)... FAVORABLE UPSLOPE CONTS OVER CAMBRIA/SOMERSET COUNTIES AFT 00 UTC MON. AT THE SAME TIME...LAKE EFFECT SNOWS WILL BECOME A CONCERN FOR WARREN/MCKEAN COUNTIES SUNDAY EVENING THROUGH MON. HOWEVER...SETUP MAY FAVOR W-E ORIENTED BANDS THAT PARALLEL THE NY/PA BORDER. SO IN COLLABORATION WITH CLE...HAVE OPTED TO HOLD BACK ON LAKE EFFECT HEADLINES AT THIS TIME. THE REMAINDER OF THIS FORECAST FEATURES A RETURN TO WINTER...WITH PERSISTENT COLD FORESEEN THROUGH NEXT WEEKEND AND BEYOND WITH SEVERAL CLIPPER TYPE SYSTEMS DROPPING THROUGH THE STRONG NW UPPER FLOW AS POSITIVE PNA PATTERN PERSISTS OVER NORTH AMERICA. SECOND WEEK OF FEBRUARY (FROM THE 10TH AND BEYOND) MAY VERY WELL FEATURE AN ARCTIC INTRUSION FROM THE NORTHERN PLAINS THROUGH THE NORTHEAST...SOMETHING NOT SEEN FOR SEVERAL WEEKS ROUND THESE PARTS. IT'S ONLY FEBRUARY...SO WE'VE GOT A LOT OF WINTER LEFT TO GO. NO CHANGES MADE TO GOING EXTENDED FORECAST THIS MORNING AS THERE'S PLENTY TO BE CONCERNED WITH IN THE SHORTER TERM. AVIATION... AREAS OF FOG THROUGH THE NIGHT WILL LEAD TO MVFR AND LOCALIZED IFR VIS AND A FEW CIGS. RAIN WILL OVERSPREAD THE ENTIRE REGION FROM SOUTH TO NORTH SATURDAY MORNING LEADING TO WIDESPREAD IFR AND AREAS OF LIFR VIS AND CIGS IN RAIN AND FOG. FLYING CONDS WILL SLOWLY IMPROVE STARTING SATURDAY EVENING AS A COLD FRONT SWEEPS THROUGH THE REGION. HOWEVER...COLDER AIR MOVING IN BEHIND THE FRONT WILL TURN ANY LINGERING RAIN SHOWERS TO SNOW SHOWERS. AREAS OF MVFR VIS AND CIGS WILL ACCOMPANY THE SNOW SHOWERS WITH LOCALIZED LIFR CONDS OVERNIGHT...MAINLY IN MTNS OF WRN AND NRN CENTRAL PA. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER STORM WATCH FOR PAZ024-033 FROM 7 PM SATURDAY TO 4 AM MONDAY. && $$ SHORT TERM... pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 1030 AM MST SAT FEB 4 2006 .SYNOPSIS...THE NEXT PACIFIC STORM WILL SEND A COLD FRONT INTO UTAH LATE TODAY AND THROUGH THE STATE TONIGHT. A COLD MOIST NORTHWEST FLOW WILL BE OVER NORTHERN UTAH SUNDAY. HIGH PRESSURE ALOFT WILL RETURN FOR NEXT WEEK. && .DISCUSSION...MORNING WATER VAPOR IMAGERY AND OBJECTIVE ANALYSIS DEPICT SHORTWAVE TROUGH TRANSLATING THROUGH PACIFIC NORTHWEST WITH 130KT JET STREAK LOCATED WITHIN BASE OF THIS TROUGH. TIGHT 700MB BAROCLINIC ZONE ADVANCING ACROSS WESTERN ID/WESTERN NV WITH ASSOCIATED SURFACE FRONT LOCATED NEAR OR/ID BORDER STRETCHING BACK INTO FAR NORTHWEST NV TO THE NW OF KWMC...BASED ON SURFACE OBS AND 3-HOUR PRESSURE RISES ACROSS MUCH OF OR/NORTHERN CA. THIS TROUGH AND ASSOCIATED JET STREAK WILL PROPAGATE THROUGH NORTHERN AND CENTRAL UTAH THIS EVENING. EXPECT THIS FRONT TO REACH THE WASATCH FRONT AROUND THE 01Z TIMEFRAME. HOWEVER NAM/RUC BOTH SUGGEST 700/500 COLD ADVECTION TO OVERSPREAD THE REGION AHEAD OF THIS FRONT. THIS MAY ALLOW SNOW SHOWERS TO DEVELOP ACROSS THE HIGHER TERRAIN OF NORTHERN UTAH BY LATE THIS AFTERNOON. EXPECT A BURST OF HEAVY PRECIPITATION ALONG THE SURFACE FRONT EARLY THIS EVENING...ALONG WITH STRONG WIND GUSTS POSSIBLY IN EXCESS OF 40 MPH ALONG THE WASATCH FRONT. PRECIPITATION SHOULD TURN OVER TO SNOW WITHIN AN HOUR OR TWO OF FROPA AS STRONG 700MB COLD ADVECTION SPREADS ACROSS THE AREA. MOUNTAIN ZONES MAY SEE WIND GUSTS IN EXCESS OF 60 MPH WITH FROPA. ADDITIONALLY MAY SEE A WEAK LAKE EFFECT EVENT LATE TONIGHT ACROSS SOUTHERN SALT LAKE/EASTERN DAVIS COUNTIES. PROGGED 700MB TEMPS AROUND -14C LATE TONIGHT COMBINED WITH LAKE TEMPS AROUND 1-2C ARE MARGINALLY SUPPORTIVE FOR DEVELOPMENT OF LAKE BANDS. INSTABILITY REMAINS ACROSS NORTHERN UT THROUGH MORNING HOURS SUNDAY BEFORE WARMING ALOFT ASSOCIATED WITH SHORTWAVE RIDGE BUILDS ACROSS REGION SUNDAY AFTERNOON. HAVE GONE AHEAD AND ISSUED A SNOW ADVISORY FOR NORTHERN/CENTRAL WASATCH FRONT AND WASATCH MOUNTAIN VALLEYS FOR THIS EVENING THROUGH THURSDAY MORNING. MOST VALLEY LOCATIONS WILL LIKELY BE IN THE 1-3 INCH RANGE WITH 2-5 INCHES EXPECTED ALONG THE BENCHES. ADDITIONALLY HAVE ISSUED A SNOW AND BLOWING SNOW ADVISORY FOR WASATCH AND WESTERN UINTA MOUNTAINS TO ACCOUNT FOR COMBINATION OF SNOW AND STRONG WINDS WITH FROPA. LASTLY...MAY NEED TO ISSUE A WIND ADVISORY THIS AFTERNOON FOR SOUTHWEST UT...AS WINDS ASSOCIATED WITH FROPA LATE TONIGHT...ALONG WITH 700MB COLD ADVECTION AND NORTHERLY GRADIENT LATE TONIGHT THROUGH SUNDAY MORNING...WILL SUPPORT GUSTY GAP WINDS. && .AVIATION...RELATIVELY STRONG COLD FRONT WILL REACH SLC ABOUT 6PM GIVE OR TAKE 1/2 HR. THERE IS ABOUT A 40 PERCENT CHANCE THAT NORTHWEST WINDS COULD GUST TO 35-40 MPH WITH THE COLD FRONT. RAIN SHOWERS WILL OCCUR WITH THE FRONT BUT WILL CHANGE OVER TO SNOW BETWEEN 8 AND 9PM. SNOW WILL OCCUR TONIGHT WITH GENERAL IFR CONDITIONS BUT TEMPORARY LIFR CONDITIONS ARE POSSIBLE BETWEEN 9PM AND 12AM. SNOW ACCUMULATIONS OF 1-3 INCHES ARE EXPECTED BY SUNDAY MORNING. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...SNOW AND BLOWING SNOW ADVISORY 5 PM TODAY THROUGH 11 AM SUNDAY ZONES UTZ007>009. SNOW ADVISORY 5 PM TODAY THROUGH 11 AM SUNDAY UTZ006. SNOW ADVISORY 7 PM TODAY THROUGH 11 AM SUNDAY UTZ002>003. WY...NONE. && $$ PUBLIC...SEAMAN AVIATION...STRUTHWOLF ut AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 1250 PM EST SAT FEB 4 2006 .SHORT TERM (SVR POTENTIAL)... THE LATEST FROM SPC... SEVERE POTENTIAL WILL INCREASE THROUGH 21Z WITH CONVECTION MOVING NEWD ACROSS ERN HALF SC...INTO CENTRAL/SRN NC. DAMAGING GUSTS AND A TORNADO OR TWO ARE POSSIBLE. AREA WILL BE MONITORED FOR POSSIBLE WW. GRADUAL DESTABILIZATION OF AIR MASS IS UNDERWAY AS WEAK SFC HEATING -- MODULATED BY CLOUD COVER -- COMBINES WITH WAA TO BOOST SFC THETAE. AS A RESULT...MODIFIED RUC SOUNDINGS SUGGEST CINH WEAKENING AND LIFTED PARCELS OVER REGION ARE BECOMING SFC BASED WITH SBCAPES AROUND 500 J/KG JUST AHEAD OF SFC COLD FRONT...AND EXPECTED TO REACH TO NEAR 1000 J/KG THROUGH EARLY-MID AFTERNOON. ACCORDINGLY...COVERAGE/INTENSITY IS SLOWLY INCREASING WITHIN BROKEN BAND OF CONVECTION...EXTENDING AT 1640Z FROM ABOUT 20 SW CLT TO 20 W NBC AND MOVING NEWD 30-35 KT. VWP AND MODEL SOUNDING WINDS YIELD FAVORABLE DEEP-LAYER SHEARS FOR BOWS AND SUPERCELLS...I.E. 60-70 KT EFFECTIVE SHEAR...AND LOW LEVEL HODOGRAPHS ELONGATED BY 40-50 KT LLJ. EXPECT INCREASING POTENTIAL FOR CONVECTIVE DOWNDRAFTS TO TRANSFER MOMENTUM DOWNWARD FROM LLJ AS WELL...RESULTING IN DAMAGING GUST THREAT WITH CONVECTION OVER REGION. WARM FRONT ANALYZED INVOF VA BORDER SHOULD LIFT SLOWLY NWD...SPREADING FAVORABLE BOUNDARY LAYER THETAE INTO EXTREME S-CENTRAL/SERN PORTION VA AS WELL. && .AVIATION... LINE OF SHOWERS AND THUNDERSTORMS EXPECTED TO FORM ALONG SFC FRONT THAT IS CROSSING THE CENTRAL APPALACHIANS. AREAS OF IFR WILL CONTINUE UNTIL FROPA...MTN RIDGES OBSCD. AFTER FROPA...ANTICIPATE MUCH IMPROVED FLIGHT CONDTIONS WITH VFR CONDITIONS RETURNING TO AREAS EAST OF THE MTNS. PERSISTENT CLOUDINESS IS EXPECTED TO CONTINUE OVER THE MOUNTAINS WITH WINDWARD RAIN SHOWERS CHANGING TO SNOW SHOWERS. STRONG SFC WINDS AND TURBULENCE ARE EXPECTED TO CONTINUE THROUGH THE TAF PD. && .PREVIOUS DISCUSSION... (ISSUED 1101 AM EST SAT FEB 4 2006) SHORT TERM (REST OF TODAY)... COMPLICATED FORECAST THIS AFTERNOON. 996 MB SFC LOW ALONG OH RIVER VCNTY HTS WILL CONTINUE TO RAPIDLY DEEPEN AND MOVE NORTHEAST THIS AFTN. ASSOCIATED SFC COLD FRONT EXTENDS SOUTH FROM THE LOW AND IS INTO WRN VA/NC. AT 15 UTC FRONT WAS FROM CRW-TNB LN. TRIPLE POINT INFLECTION (SECONDARY LOW PRESSURE CENTER) WAS OVER NW NC WITH WARM FRONT EXTENDING ENE ACROSS EXTREME NRN NC INTO SOUTHEAST VA...ALONG A UKF-DAN-RIC LINE. AIRMASS SOUTH OF THIS WARM FRONT IS SOUPY WITH SFC DEWPOINTS IN THE U50S. THIS BOUNDARY...ALONG WITH COLD FRONTAL BOUNDARY WILL BE THE FOCUS FOR DEEP CONVECTION THIS AFTN...POTENTIALLY SVR PER STRONG LOW LEVEL SHEAR AND STEEP MID LEVEL LAPSE RATES. THERE HAVE ALREADY BEEN A COUPLE SPOTTER REPORTS OF PEA SIZE HAIL VCNTY OF TNB ASSOCIATED WITH TSRA IN ADDITION TO A SUDDEN STRONG WIND GUST WITH FROPA. THIS FRONT WILL CROSS THE ENTIRE CWA THIS AFTN...THE GREATEST THREAT FOR SVR DEEP CONVECTION CONFINED TO AREAS ALONG AND SOUTH OF TRIPLE POINT LOW. NORTH OF BOUNDARY...AIMASS MAY BE TOO STABLE TO MIX DOWN THE WIND. ATTM WILL LEAVE GRID TEMPS ALONE. WE ARE FCSTNG TEMPS TO RECOVER INTO THE 50S AS THE WARM FRONT PUSHES NORTH. BIG QUESTION IS WHETHER WARM FRONT CAN MOVE NORTH FAST ENOUGH B4 THE COLD FRONT GETS HERE...THUS SENDING THE TEMPS IN THE OTHER DIRECTION. ASIDE FROM THE SVR POTENTIAL...SECOND DELIMA IS SNOW FCST AND NEED FOR HEADLINES TONIGHT AND SUNDAY FOR WINTRY PRECIP. WRN AREAS WILL LIKLEY SEE A CHANGE OVER TO SNOW BY SUNSET WITH AN ACCUMULATING SNOW FOR OUR FAR WRN COUNTIES...FIRST FROM THE DEEPER WRAP AROUND MOISTURE FROM THE OH VALLEY LOW...THEN MORE TO A PURE UPSLOPE SNOW EVENT FOR THE WINDWARD SLOPES IN THE FAR WRN CWA LATER TONIGHT AND SUNDAY...THE MOISTURE PROFILES BECOMING SHALLOWER WITH TIME. BASED ON THE QPF...A WARNING MAY BE NEEDED FROM GREENBRIER NORTHWARD...UPWARDS OF 8 INCHES POSSIBLE IN THE MTNS NW OF LEWISBURG. FARTHER SOUTH...AMOUNTS WILL BE HIGHLY VARIABLE...AN INCH IN THE MTN VALLEYS...BUT UPWARDS OF 3 INCHES AT ELEVATIONS ABOVE ABOVE 3000 FEET...COULD SQUEEK OUT 4 INCHES AT FLAT TOP WV...MT ROGERS VA...BEECH MTN NC. SINCE THE ACCUMULATION WILL BE SO ELEVATION DEPENDENT...SEE NO NEED FOR A WARNING...ALTHOUGH MAY ISSUE A SNOW ADVISORY FOR THESE AREAS WITH THE AFTN FCST PACKAGE. INSTEAD OF A SNOW ADVISORY HEADLINE MAY CONSIDER A WINTER WEATHER ADVISORY FOR COMBINATION OF SNOW AND STRONG WIND. AS FOR THE WIND...THERE WILL BE A BURST OF WIND WITH FROPA...25-35 MPH...THEN SECONDARY INCREASE IN THE WIND OVERNIGHT AS THE SUBSIDENCE AND GRADIENT WIND INCREASES IN THE WAKE OF THE DEEPENING LOW. FCST CROSS BARRIER FLOW LATER TONIGHT AND EARLY SUNDAY IS ABOUT 45 KTS. THIS MAY REQUIRE A HEADLINE FOR ADVISORY CRITERIA WIND IN THE MTNS...BUT AGAIN...MAY CHOOSE TO COMBINE IT WITH THE WSW. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...WINTER STORM WATCH FOR WVZ045 FROM 6 PM SATURDAY TO MIDNIGHT MONDAY. && $$ va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FLAGSTAFF AZ 930 PM MST SAT FEB 4 2006 .SYNOPSIS...EXTENSIVE HIGH LEVEL CLOUDS WILL STREAM ACROSS NORTHERN ARIZONA TONIGHT. THESE CLOUDS ARE OUT AHEAD OF A COLD FRONT THAT WILL DROP SOUTHWARD INTO ARIZONA EARLY SUNDAY MORNING. THIS FRONT WILL BRING COOLER AFTERNOON TEMPERATURES ALONG WITH NORTH TO NORTHEAST WINDS...ESPECIALLY FOR AREAS NORTH OF THE MOGOLLON RIM. DRY WEATHER AND ABOVE NORMAL TEMPERATURES ARE EXPECTED MONDAY THROUGH WEDNESDAY. && .DISCUSSION... THIS EVENINGS SATELLITE LOOP SHOWING EXTENSIVE CIRRUS CLOUDS OVER THE CWA. THESE CLOUDS ARE COMING IN ON WESTERLY FLOW AT THE H4 LEVEL. THERE IS A SURFACE COLD FRONT RUNNING FROM SOUTH CENTRAL UTAH TO DEATH VALLEY. RH PROGS AT H4 AND ABOVE INDICATE THE CLOUD FIELD TO STICK AROUND UNTIL EARLY MORNING AND THEN BE SHUNTED SOUTHWARD AS THE DRY COLD FRONTAL SYSTEM MOVES INTO NORTHERN ARIZONA. USING THE RUC LOW LEVEL WINDS AND THETA PROGS...THE FRONT IS EXPECTED TO CROSS THE NORTHERN BORDER AFTER MIDNIGHT. ON SUNDAY...GFS AND ETA IN GOOD AGREEMENT WITH THE LARGE SCALE FEATURES. BOTH MODELS HAVE A RIDGE AMPLIFYING OVER CENTRAL CALIFORNIA. THIS PUTS NORTHERN ARIZONA IN NORTHWEST FLOW ALOFT AND RH PROGS INDICATE THE CLOUD FIELD CURRENTLY OVERHEAD WILL BE SHUNTED SOUTHWARD. BRISK NORTHERLY WINDS ARE EXPECTED HERE AS SURFACE HIGH PRESSURE DEVELOPS OVER NORTHERN UTAH. MONDAY AND TUESDAY...PROGS BRING A WEAKENING RIDGE OF HIGH PRESSURE OVER ARIZONA. BY TUESDAY...WESTERLY FLOW ALOFT IS INCREASING ACROSS SRN CAL AND IS SHOWN TO BRING IN SOME MORE MID AND HIGH LEVEL CLOUDS. DL && .AVIATION...FOR THE 06Z PACKAGE...EXPECT VARIABLE HIGH CLOUDS ALONG AND SOUTH OF A KLAS TO KFMN LINE OVER THE NEXT 24 HOURS WITH CLEARING SKIES TO THE NORTH. BREEZY CONDITIONS CAN BE EXPECTED IN THE AFTERNOON ALONG AND BEHIND THE COLD FRONT SUNDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ az AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 231 AM MST SUN FEB 5 2006 .DISCUSSION...FORECAST CONCERNS THIS MORNING INCLUDE WINDS AS WELL AS PRECIPITATION CHANCES. THEN CONCERNS BECOME TEMPERATURES THROUGH MUCH OF THE UPCOMING WEEK. RECENT SURFACE ANALYSIS INDICATES A TROUGH OF LOW PRESSURE DEVELOPING OVER EASTERN COLORADO AS STRONG UPPER TROUGH APPROACHES AND MOVES THROUGH OUR REGION TODAY. LATEST IR AND WATER VAPOR SATELLITE IMAGERY SHOWS CYCLONIC SPIN OF ENERGY IN TROUGH MOVING SOUTHEAST THROUGH WYOMING WITH EVEN A FEW LIGHTNING STRIKES SEEN EARLIER IN NORTHERN UTAH. GFS AND NAM MODELS BOTH IN GOOD AGREEMENT WITH STRENGTH AND PROGRESSION OF THIS SYSTEM FOR TODAY. WILL GO WITH A BLEND OF BOTH MODELS THROUGH THE SHORT TERM. FOR TODAY FIRST CONCERN BECOMES THE WIND AS WELL AS SMALL CHANCES FOR PRECIPITATION. MODELS INDICATE GOOD MOISTURE AND DYNAMICS FROM AROUND 850 MB AND UP WITH DRIER ATMOSPHERE BELOW. GOOD DOWNWARD MOMENTUM SHOWN BY MODELS ESPECIALLY BETWEEN 15Z AND 00Z TODAY ACROSS OUR EASTERN COLORADO AND FAR WESTERN KANSAS ZONES. IN ADDITION LOOKS LIKE THERE COULD BE SOME SNOW SHOWERS AROUND WITH ETA AND RUC SOUNDINGS SHOWING THIS. APPEARS BEST CHANCES FOR PRECIPITATION WILL EXIST OVER OUR NORTHERN ZONES SO HAVE INCREASED AFTERNOON CHANCES TO 30 POPS THERE WITH SLIGHT CHANCE 20 POPS ELSEWHERE. ALSO STRONG NORTHWEST WINDS ALOFT SHOULD MIX DOWN FOLLOWING FRONTAL PASSAGE THIS MORNING THROUGH THIS AFTERNOON. THEREFORE A WIND ADVISORY HAS BEEN ISSUED FOR OUR EASTERN COLORADO AND WESTERN MOST ROWS OF KANSAS ZONES. HAVE LOWERED HIGH TEMPERATURES A BIT ALL ZONES DUE TO MORE CLOUDS AS WELL AS EFFECTS FROM THE FRONTAL PASSAGE EARLY IN THE DAY. MAY SEE LITTLE MORE SUN WITH LESS MOISTURE IN THE SOUTHWEST AND WESTERN ZONES. THUS TRENDED TEMPERATURES FROM LOW 40S WEST TO MID TO UPPER 30S EAST. FOR TONIGHT TROUGH MOVES RAPIDLY AWAY FROM THE AREA. WILL STILL KEEP A SLIGHT CHANCE MENTION FOR LIGHT SNOW SHOWERS EASTERN ZONES FOR THE EVENING. WENT CLOSE TO GUIDANCE FOR LOW TEMPERATURES FROM THE TEENS IN EASTERN COLORADO TO THE LOWER 20S ELSEWHERE. EXPECT WINDS TO DIMINISH RAPIDLY AFTER SUNSET AS WELL. FOR MONDAY THROUGH TUESDAY DID NOT MAKE MUCH IN THE WAY OF CHANGES. RIDGING MOVES OVER AREA MONDAY AND MONDAY NIGHT BEFORE NEXT UPPER TROUGH MOVES THROUGH ON TUESDAY. WINDS BECOME LIGHT ON MONDAY AS WELL. MOISTURE WILL BE LACKING WITH THIS SYSTEM AS HAS HAPPEN SO MUCH RECENTLY. DID NOT MAKE MUCH CHANGE TO TEMPERATURES WITH HIGHS IN THE 40S AND LOWS IN THE TEENS AND 20S. FOR THE EXTENDED FORECAST PERIOD WEDNESDAY THROUGH SATURDAY MADE VERY LITTLE CHANGE EXCEPT TO LOWER HIGH TEMPERATURES A BIT FOR SATURDAY AS COLDER AIR APPEARS BY BOTH GFSLR AND ECMWF MODELS TO RESIDE OVER OUR REGION AS STRONG ARCTIC HIGH PRESSURE MOVES INTO REGION FROM THURSDAY AND BEYOND. WILL STILL SEE HIGH TEMPERATURES MAINLY IN THE LOWER 40S WITH LOWS IN THE TEENS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND ADVISORY FROM 8 AM MST /9 AM CST/ THIS MORNING TO 4 PM MST /5 PM CST/ THIS AFTERNOON FOR KSZ001-KSZ013-KSZ027-KSZ041. NE...WIND ADVISORY FROM 8 AM THIS MORNING TO 4 PM MST THIS AFTERNOON FOR NEZ079. CO...WIND ADVISORY FROM 8 AM THIS MORNING TO 4 PM MST THIS AFTERNOON FOR COZ090-COZ091-COZ092. && $$ LAMMERS ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 318 AM CST SUN FEB 5 2006 .DISCUSSION... MAIN CONCERN WITH THIS FORECAST PACKAGE WILL BE THE CHANCE OF SNOW TODAY AND HOW MUCH ACCUMULATION IS POSSIBLE. TODAY: LATEST WATER VAPOR LOOP SHOWING THE UPPER LEVEL WAVE MOVING ACROSS THE ROCKIES. THE VORT LOBE ASSOCIATED WITH THIS FEATURE APPEARS TO BE NEAR THE UTAH/COLORADO BORDER. RIGHT NOW...IT DOES NOT APPEAR LIKE THIS FEATURE IS DIGGING THAT MUCH...BUT THERE IS A HINT OF DRY SLOT TRYING TO REDEVELOP OVER WESTERN COLORADO. THE RUC APPEARS TO HAVE THE SURFACE LOW PLACED TO FAR EAST...SO THIS WAVE MAY END UP COMING THROUGH A LITTLE SLOWER THAN PROGGED. WE ARE CONTINUING TO PLAY THE CONSERVATIVE ROUTE ON POPS THIS AFTERNOON AND TONIGHT. THE NAM DOES SHOW THE THETA SURFACES REALLY RISING BETWEEN 280-290K DURING THE AFTERNOON. THIS WILL HELP SATURATE THINGS UP FAIRLY QUICKLY. THERE IS EVEN A HINT OF MID LEVEL INSTABILITY WHEN THIS MID LEVEL COLD POCKET MOVES THROUGH LATE THIS AFTERNOON AND EVENING. COBB OUTPUT FROM THE ETA IS NOT SHOWING ANY SNOW ACCUMULATION AT ALL THIS EVENING, BUT THE GFS IS SHOWING BETWEEN 0.5 AND 1 INCH AROUND CHANUTE. THIS MAY BE A BIT OVERDONE...SINCE THIS WAVE LOOKS TO BE STARVED FOR MOISTURE...EVEN THOUGH THE DYNAMICS LOOK GOOD. WE ARE NOT GOING TO MAKE MANY CHANGES AT THIS TIME...BUT WE MAY ADD THE POTENTIAL FOR SOME FREEZING DRIZZLE MAINLY WEST OF THE I-35/135 CORRIDOR TONIGHT DUE TO A LOW LEVEL COLD POCKET AROUND 280K MOVING THROUGH THE REGION. WE ARE NOT GOING TO MENTION ANY HEADLINE SINCE IT LOOKS LIKE THIS DRIZZLE WILL BE PATCHY IN NATURE WHICH SHOULD KEEP MOST OF THE ROADWAYS IN GOOD SHAPE. DOWNGLIDE WILL ALSO BE TAKING OVER AFTER MIDNIGHT. LOW IFR CEILINGS MAY ALSO BE A PROBLEM ACROSS THE I-35/135 CORRIDOR AFTER 03Z AND CONTINUE OVERNIGHT. WE DID RAISE TEMPERATURES SLIGHTLY ACROSS SOUTH CENTRAL AND SOUTHEAST KANSAS TODAY...BUT THE CLOUDS SHOULD KEEP THEM DOWN. FORECAST CONFIDENCE IS ON THE LOW END OF HIGH. SUNDAY NIGHT-TUESDAY: NO REAL BIG CHANGES DURING THIS TIMEFRAME AS SURFACE HIGH PRESSURE BUILDS IN FROM THE ROCKIES. THE UPPER LEVEL PATTERN ALSO DOES NOT SHOW MUCH OF A CHANGE EITHER WITH THE POSITION OF THE TROF IN THE EAST. THIS WILL ALLOW FOR A CANADIAN CLIPPER TO PASS THROUGH REGION TUESDAY. THIS SYSTEM WILL ALSO BE MOISTURE STARVED. THEREFORE...WE WILL NOT BE ADDING POPS DURING THIS TIMEFRAME. FORECAST CONFIDENCE IS IN THE MEDIUM RANGE. WEDNESDAY-SATURDAY: WE ARE NOT MAKING A WHOLE LOT OF CHANGES TO THIS PORTION OF THE FORECAST PACKAGE EITHER. THE ECMWF CONTINUES TO BE FAIRLY CONSISTENT WITH THE TROF DEEPENING ACROSS THE EAST WHICH WILL ALLOW FOR MORE POLAR AIR TO ENTER THE REGION FRIDAY AND SATURDAY. THE GFS TENDS TO AGREE MORE WITH THE UKMET AND IS TENDING TO FLIP FLOP A LITTLE ON THE COLD AIR. HOWEVER...THEY ARE ALL SHOWING A COLD POLAR HIGH DROPPING INTO THE REGION WHICH WILL ALLOW TEMPERATURES TO DROP BELOW SEASONABLE NORMS. WE DID TWEAK TEMPERATURES DOWN A DEGREE OR TWO ON FRIDAY...BUT IT STILL LOOKS DRY DUE TO LACK OF GOOD MOISTURE FETCH. FORECAST CONFIDENCE IS MEDIUM. COX && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 47 23 47 23 / 10 20 0 0 HUTCHINSON 46 23 47 23 / 20 20 0 0 NEWTON 45 23 46 23 / 20 20 0 0 ELDORADO 45 23 47 23 / 10 30 5 0 WINFIELD-KWLD 48 24 48 23 / 10 20 0 0 RUSSELL 42 22 46 22 / 20 20 0 0 GREAT BEND 45 22 46 22 / 20 20 0 0 SALINA 42 22 45 22 / 20 20 0 0 MCPHERSON 45 22 46 22 / 20 20 0 0 COFFEYVILLE 45 24 47 24 / 10 30 10 0 CHANUTE 42 24 46 23 / 10 30 10 0 IOLA 42 24 45 23 / 10 30 5 0 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 345 AM EST SUN FEB 5 2006 .SHORT TERM (TODAY AND TONIGHT)... THE MAIN CONCERNS FOR THE SHORT TERM IS ENDING THE VERY LIGHT SNOW OR FLURRIES AND THEN DEALING WITH THE CLOUD TRENDS. NO MORE EVIDENCE OF FLURRIES OVER THE SOUTHWEST THIRD OF FA....AND MOST OF THE FLURRIES ON OUR LOCAL RADAR ARE SOUTH AND EAST OF SDF AND DRIFTING OFF TO THE SOUTHEAST. HOW TO HANDLE THE DECREASING CLOUDINESS LATER TODAY AND TONIGHT IS A MORE IMPOSING PROBLEM. REALLY PREFER THE SOMEWHAT SLOWER RUC VERSUS THE NAM AND GFS TRENDS. WI DAYTIME HEATING...CYCLONIC LOW LEVEL FLOW...SOME BACKBUILDING CLOUD TRENDS LATER THIS MORNING SHOULD DELAY THE CLEARING. THEN LATER TODAY AND TONIGHT...SOME INCREASE IN MID OR HIGH CLOUDS IN ADVANCE OF THE NEXT STORM SYSTEM DROPPING SE INTO THE CENTRAL PLAINS STATES BY TONIGHT. HIGH TEMPS TODAY LOWER 30S NE TO MID TO UPPER 30S SOUTHWEST PORTION OF FA...MIN TEMPS TONIGHT UPPER TEENS TO LOWER 20S. --21 .LONG TERM (MONDAY THRU SUNDAY) (MONDAY AND TUESDAY)... DECENT AGREEMENT THIS PERIOD...WITH STRONG H500 LOW ACROSS QB...AND +PNA PATTERN(W CONUS RIDGE/E CONUS TROUGH) REMAINING IN PLACE. WNW FLOW ACROSS THE REGION...WITH LOW MOVING ACROSS THE GULF STATES MONDAY...A FEW CLOUDS MAY EXIST ACROSS THE SOUTHERN ZONES NEAR THE TN BORDER...WITH MODEST AMOUNTS OF SUNSHINE ACROSS THE REST OF THE AREA MONDAY. WEAK RIDGING INTO THE AREA LATE MONDAY INTO EARLY TUE...A FEW MORE CLOUDS WORKING INTO THE AREA WITH MODELS SHOWING SOME MID LEVEL MOISTURE MOVING EAST FROM THE PLAINS INTO THE OH VLY. WILL GO SLIGHTLY UNDER THE MOS BLEND FOR EACH DAY...WITH READING EACH DAY ABOUT 3 DEGREES BELOW NORMAL.--SCHOTT IN THE EXTENDED (WEDNESDAY THROUGH SUNDAY)... EXTENDED MODELS ARE ALL OVER THE PLACE...WITH OPERATIONAL MODELS JUMPING FROM SOLUTION TO SOLUTION...TONIGHT IS WAS THE 00Z ECMWF TURN TO DO SO. MODELS NOT DOING A DECENT JOB AT ALL IN PICKING OUT THE SHRTWV ENERGY...USING ENSEMBLE MEANS FROM GFS AND CAN...WITH SOME SUPPORT FROM THE ECMWF. HAVE STAYED CLOSE TO ENSEMBLE MEANS...SLIGHTLY COLDER SATURDAY AND SUNDAY. ENSEMBLES TEND TO FAIR BETTER WITH SUCH WIDE VARIANCE IN THE OPER MODELING. MODELS HAVE BEEN CONSISTENT WITH THE POSSIBILITY OF LIGHT SNOW/FLURRIES WITH A WEAK SHRTWV DROPPING ACROSS THE OH VLY WEDNESDAY...WILL CONTINUE. THE FIRST CHANGE IN THE 00Z RUNS TONIGHT WAS CREATING SOME WEAK RIDGING THURSDAY ACROSS THE AREA...WITH BOTH ECMWF AND GFS SHOWING WITH GO ALONG HERE AND DIFFER FROM THE ENSEMBLES FOR THURSDAY ONLY. DRY THURSDAY WITH SOME WAA ACROSS THE REGION AHEAD OF THE NEXT FRONT DROPPING SOUTHEAST ACROSS THE UPPER MS VALLEY. THE WAA MAY CAUSE THE PRECIP FRIDAY TO START AS RAIN/SNOW MIX BEFORE TURNING TO LIGHT SNOW BEHIND THE SYSTEM FRIDAY LATE AFTERNOON/EVENING. DIFFERENCES REALLY START TO EXPAND BETWEEN THE GFS AND ECMWF AT SATURDAY...ECMWF HAS TURNED UP A WARMER SOLUTION THAN LAST FEW RUNS...KEEPING THE REALLY COLD AIR IN SOUTHERN CANADA...MAINLY DUE THE RELAXING OF THE NORTH ATLC BLOCKING. THE GFS STILL BRINGS THE REALLY COLD AIR INTO THE GREAT LAKES AND OH VALLEY SATURDAY INTO SUNDAY. HAVE GONE WITH A BLEND OF THESE SOLUTIONS UNTIL MORE CONSISTENCY SHOWS. SO THAT LEADS TO THIS SOLUTION...SATURDAY THE MOISTURE LOOKS SHALLOW...HAVE KEPT FLURRIES IN THE FORECAST WITH SOME MOISTURE IN THE ICE CRYSTAL GROWTH REGION. YSTDY'S RUNS SHOWED SOME POTENTIAL FOR MORE SNOW ON SATURDAY...LOOKS VERY UNLIKELY NOW WITH NEITHER THE OPER OR ENSEMBLES SHOWING THIS POSSIBILITY. SUNDAY AN ANOTHER SYSTEM MAY DIVE SOUTH OUT OF CENTRAL CANADA...HAVE PLACED LOW CHC POPS IN THE FORECAST. --SCHOTT && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1225 AM EST SUN FEB 5 2006 .AVIATION... NAM IS DOING A MUCH BETTER JOB WITH THE SURFACE LOW AS IT BOTTOMS OUT JUST TO THE SOUTHEAST TIP OF LAKE HURON. FRONTO-GENETIC FORCING CONTINUES TO WRAP SOUTHWEST INTO THE CWA...AND NAM SUGGESTS THIS WILL NOT ABATE TOO MUCH OVERNIGHT. SO...EXPECT FNT/MBS TO BE IN AND OUT OF AT LEAST MODERATE SNOW OVERNIGHT...WITH DTW/DET SHARING IN JUST A BIT OF THIS. DOWNSLOPING NORTHWEST FLOW OFF THE IRISH HILLS IS KEEPING CONDITIONS BORDERLINE IFR/MVFR IN/AROUND DETROIT. WILL TAPER THE SNOW OFF SUNDAY MORNING...BUT KEEP THE NORTHWEST WIND BLOWING THROUGHOUT THE DAY...DIMINISHING SOME WITH THE DECOUPLING OF THE BOUNDARY LAYER BY TOMORROW EVENING. && .UPDATE #2...ISSUED AT 1210 AM UPDATED TO DOWNGRADE WAYNE COUNTY FROM A WARNING TO SNOW/BLOWING SNOW ADVISORY. FROTOGENETIC BANDING CONTINUES TO ROTATE BACK INTO THE CWA...WITH A NUMBER OF THE BANDS JUST MAKING IT INTO PARTS OF WAYNE COUNTY...BUT NO FURTHER. HEAVIEST SNOW...BY AND LARGE...WILL CONTINUE FROM M 59 NORTH INTO THE THUMB AND PARTS OF THE SAGINAW VALLEY...WHERE WARNING APPEARS IN VERY GOOD SHAPE WITH PLENTY OF REPORTS IN THE 5 TO 6 INCH RANGE ALREADY THIS EVENING. EDGED DOWN SNOW AMOUNTS SOUTH OF DETROIT...WITH NO MORE THAN 1-3 INCHES IN LENAWEE/MONROE (SOME WILL BE LUCKY TO GET THAT MUCH). && .UPDATE...ISSUED AT 825 PM UPDATED TO DOWNGRADE THE WARNING IN WASHTENAW...LENAWEE AND MONROE COUNTIES TO A SNOW/BLOWING SNOW ADVISORY WITH TEMPERATURES ABOVE FREEZING THIS EVENING...ACCUMULATION HAS BEEN HARD TO COME BY. THE MAIN SURGE OF MOISTURE IS NOW BACKING INTO THE AREA...AND WITH WITH TEMPERATURES NOW AROUND 33 AND FALLING...EXPECT ACCUMULATION TO COMMENCE. HOWEVER...THESE AREAS ARE ON THE SOUTHWESTERN EDGE OF THE BEST MOISTURE...SO DOUBT THEY WILL DO ANY BETTER THAN 3-5 INCHES OF SNOW...AND LIKELY LESS TOWARD THE OHIO BORDER. LEFT WAYNE COUNTY IN THE WARNING...ALTHOUGH MUCH OF THE COUNTY WILL FALL SHORT OF 6 INCHES GIVEN THE SLOW TURN OVER/ACCUMULATION. EVEN SO...THEY ARE ON THE PIVOT POINT OF THE AFOREMENTIONED SURGE OF MOISTURE...SO EXPECT A PRETTY TIGHT GRADIENT FROM NORTH TO SOUTH ACROSS THE COUNTY WITH THE NORTHERN BORDER PUSHING 5 OR 6 INCHES AND THE SOUTH CLOSER TO 3 MAYBE 4 INCHES BY SUNDAY MORNING. FURTHER NORTH...EXPANDED THE WARNING INTO THE SAGINAW VALLEY (BAY... SAGINAW AND SHIAWASSEE COUNTIES). TEMPERATURES HAVE FINALLY DROP TO FREEZING AND CONTINUE TO FALL. THE MAIN MOISTURE SURGE FROM THE SOUTHEAST IS POINTED RIGHT INTO THIS AREA. 18Z MODELS SUGGESTED 6-7 INCHES OF SNOW IN THE 00Z-12Z TIMEFRAME...AND RADAR/SATELLITE TRENDS NOW BARE THIS OUT. LEFT MIDLAND COUNTY AS AN ADVISORY BEING A BIT TOO FAR WEST. && .AVIATION...ISSUED AT 600 PM ALTHOUGH HEAVIER SNOWFALL HAS BEEN COMING IN POCKETS SO FAR...WITH SOME OF THE LIGHTER PERIODS STILL MIXED WITH RAIN...CONDITIONS WILL REMAIN IN THE IFR RANGE DUE TO LOW CEILINGS. 18Z MODELS ALL INSIST ON A RATHER IMPRESSIVE INCREASE IN SNOWFALL INTENSITY/COVERAGE BY 01/02Z...CARRYING ON THROUGH ABOUT 06-07Z. THERE AREA FINALLY SOME SIGNS OF THIS ON SATELLITE AS A STEADY ENHANCEMENT IN CLOUD FEATURES HAS BEEN ONGOING IN THE SOUTHEAST FEED OF MOISTURE OVER LAKE ERIE BACK TOWARD THE AREA. IN ADDITION...RADAR RETURNS HAVE RESPONDED IN THIS AREA. SO...STILL EXPECT A WINDOW OF MODERATE/HEAVY SNOW IN THE 01Z-05Z TIMEFRAME DTW/DET TRENDING INTO MBS BY 03Z-07Z. WILL TAPER THE SNOW OFF A BIT LATE TONIGHT...BUT KEEP VISIBILITIES DOWN IN THE 1-3SM MILE AREA WITH -SN/BLSN. SNOW WILL THEN TAPER OFF TO FLURRIES ON SUNDAY MORNING...W/ JUST BLSN IN GUSTY NORTHWEST FLOW PERSISTING IN THE AFTERNOON. && .SHORT TERM...TONIGHT AND SUNDAY...ISSUED AT 407 PM 12Z RAOBS/WATER VAPOR LOOP SHOW LONGWAVE TROUGH FROM THE GREAT LAKES TO THE GULF COAST. STRONG SHORTWAVE LIFTING INTO OHIO...WITH SECONDARY ENERGY OVER WISCONSIN/ILLINOIS. WATER VAPOR/HEIGHT ANALYSIS ALREADY SHOWS SIGNS OF CUTTING OFF AS THE SYSTEM WRAPS UP. 18Z ACARS OBSERVATIONS AROUND 30KFT SHOW A WIDESPREAD AREA OF +150KTS...WITH ONE REPORT OF 175KTS. SURFACE ANALYSIS SHOWS LOW OVER SOUTHEASTERN OHIO...WITH AN INCREASING AREA OF PRESSURE FALLS OVER CENTRAL LAKE ERIE. REGIONAL RADARS SHOW WIDESPREAD PRECIP ACROSS SOUTHEAST MICHIGAN. METARS ACROSS MUCH OF THE CWA HAVE CHANGED OVER TO SNOW...WITH CHANGE OVER WORKING ITS WAY FROM SOUTHEAST TO NORTHWEST. FEW STATIONS IN THE WESTERN AND NORTHERN CWA AWAY FROM THE HEAVIER PRECIP RATES STILL REPORTING RAIN. UPPER TROUGH TAKING ON A NEGATIVE TILT AS THE STRONG UPPER JET/SHORTWAVE LIFTS THROUGH THE OHIO VALLEY. SURFACE LOW CONTINUES TO TAKE A MORE LEFT/NORTHWARD TURN AS WELL...LEADING TO A CONTINUATION OF THE EARLIER WESTWARD TREND AND OVERALL IN LINE WITH THE GOING FORECAST. COMPARED TO 18Z ACARS OBSERVATIONS...12Z RUNS STILL UNDERDO THE STRENGTH OF THE DOWNSTREAM JET...BY ABOUT 6 HOURS AND AT LEAST 10KTS. THIS SHOULD LEAD TO A CONTINUED STRENGTHENING OF THE SURFACE LOW...WITH A FASTER TRACK INTO ONTARIO TONIGHT. THIS COULD LEAD TO A SHORTER PERIOD OF SNOW ACROSS THE SOUTHWESTERN CWA. GOOD MOISTURE FLUX AND FRONTOGENESIS TO THE NORTHWEST OF THE SYSTEM LEADING TO WIDESPREAD PRECIP AND MODEST SNOWFALL RATES ALREADY. SPOTTER REPORTS FROM DTX/PTK SOUTHWARD INDICATE SNOW IS BEGINNING TO ACCUMULATE...WITH UP TO HALF INCH IN 45 MINUTES REPORTED. TAMDAR SOUNDINGS INTO DTW SHOW THE PROFILE ALL BELOW FREEZING...WITH SOUNDINGS FARTHER NORTH AND WEST STILL SHOW FREEZING LEVELS >1.2KFT. ONCE HEAVIER PRECIP MAKES IT NORTHWESTWARD...EXPECT MELTING AND DYNAMIC COOLING TO ALLOW PRECIP TO QUICKLY CHANGE OVER TO ALL SNOW. ONE ADDITIONAL CONCERN IS WITH CONVECTIVE POTENTIAL ACROSS THE SOUTHERN CWA. 18Z RUC CROSS SECTIONS SHOWS WEAK TO NEUTRAL STATIC STABILITY...WHILE THE 12Z NAM IS ACTUALLY CONVECTIVELY UNSTABLE WITH THETA-E FOLDED OVER. LDN ACTUALLY PICKED UP A COUPLE LIGHTNING STRIKES OVER WESTERN LAKE ERIE AND NEAR TOLEDO. AM TEMPTED TO HOLD OFF ON MENTIONING THUNDER AS THE NAM WINDOW OF INSTABILITY IS PRETTY SHORT AND DIMINISHES AFTER 21Z. COULD SEE SOME HEAVY PRECIP RATES THOUGH...AS CAN BE INFERRED FROM SNOW THAT IS ALREADY ACCUMULATING ACROSS THE SOUTHERN CWA. THE FASTER TREND MAY LIMIT THE DURATION OF SNOWFALL ACROSS THE FAR SOUTHWEST...AS THE SYSTEM PULLS OUT FASTER. HOWEVER EXPECT THE SNOWFALL RATES THIS EVENING WITH WEAK STABILITY TO HELP US REALIZE THE WARNING CRITERIA SNOWFALL...AND THEREFORE WILL KEEP THE WARNING GOING. THE WESTWARD TREND WOULD ALLOW THE TROWAL TO SETUP FARTHER WEST AND NORTH ACROSS THE THUMB AND INTO NORTHERN LOWER. WILL BUMP SNOW ACCUMULATIONS UP A BIT OVER TOWARD BAY COUNTY. HOWEVER GIVEN THE SLOWER CHANGEOVER AND QUESTIONABLE ENHANCEMENT THAT FAR WEST WILL KEEP THEM IN AN ADVISORY. ELSEWHERE SNOW TOTAL STILL LOOK GOOD...WITH GREATEST AMOUNT ACROSS THE THUMB WITH SOME ENHANCEMENT IN THE NORTHERLY FLOW OFF HURON. WILL MENTION DEFINITE BLOWING SNOW ACROSS THE CWA TONIGHT AS FORECAST SOUNDINGS/TIME SECTIONS SHOW THE MIXED LAYER TAPPING INTO 40KTS A FEW THOUSAND FEET OFF THE SURFACE. GOOD CYCLONIC FLOW ON SUNDAY WITH TRAILING SHORTWAVE SWINGING THOUGH. LAKE EFFECT SETUP IS NOT ALL THAT IMPRESSIVE...ALTHOUGH SOME SYNOPTIC LIFT WITH RELATIVELY DEEP MOISTURE PRESENT COULD LEAD TO SOME ENHANCEMENT. THEREFORE WILL HOLD ONTO LIKELY POPS AT LEAST THROUGH THE MORNING DESPITE A QUICKER DEPARTURE TO THE SYSTEM. ADDED AREA OF BLOWING SNOW AS WELL WITH A STRONG GRADIENT AND CONTINUED DEEP MIXED LAYER. && .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...ISSUED AT 407 PM WEEKEND SURFACE LOW SLOWLY RETREATING NORTHEAST THROUGH QUEBEC THROUGH EARLY PART OF WEEK AS ASSOCIATED CYCLONIC FLOW BACK ACROSS THE FORECAST AREA AND EASTERN GREAT LAKES REGION SLOWLY WANES. AT THE SAME TIME...THE CLOSED STACKED LOW ALOFT VERY SLOWLY RETREATING NORTH/NORTHEAST. AFTER MODEST DEEPER MOISTURE WANES SUNDAY NIGHT...ESPECIALLY SOUTH...THIS DEEPER MOISTURE RATHER MEAGER THROUGH EARLY PART OF WEEK. LOWER LEVEL RELATIVE HUMIDITIES...ON THE OTHER HAND...REMAIN GENERALLY HIGH THROUGH EARLY WEEK. DYNAMICS SLIGHT AT BEST FROM TIME TO TIME THROUGH EARLY WEEK...INCLUDING LOW TO MID LEVEL QVECTOR CONVERGENCE...SURFACE CONVERGENCE AND OMEGA LIFT. QPF FIELDS ALSO VERY LIGHT...AND NAM ESSENTIALLY EVEN DRY THROUGH TUESDAY. GFS MODEL SOUNDINGS SHOW BETTER LOW LEVEL MOISTURE THAN NAM... TAPPING COLDER THAN MINUS 10C TEMPERATURES FOR ICE NUCLEI...AND WITH NEARLY DRY ADIABATIC LOW LEVEL LAPSE RATES MUCH OF THE TIME WITH WEST TO NORTHWEST FLOW...HAVE MENTIONED AT LEAST FLURRY CHANCES THROUGH EARLY WEEK. DURING THE MID WEEK PERIOD INTO THE WEEKEND... MODELS SHOW SOME CONSENSUS TOWARD SURFACE RIDGING OVERHEAD WEDNESDAY...THEN CONSIDERABLE TIMING/DETAIL DIFFERENCES AMONG MODELS AS TO BRINGING OF CLIPPER ON DOWN INTO LAKES REGION...WHICH WHEN THIS DOES HAPPEN WILL BE ACCOMPANIED BY A RESURGENCE OF COLD ARCTIC AIR LATE NEXT WEEK. AT 500 MB...CONSIDERABLE DETAIL DIFFERENCES AMONG MODELS ESPECIALLY WITH RESPECT TO TIMING AND PLACEMENT OF INDIVIDUAL SHORTWAVE TROUGH IMPULSES...BUT MAIN IDEA IS FOR LOWERING HEIGHTS LATTER PART OF WEEK...AND WITH AVAILABLE MODELS SHOWING IMPROVED MOISTURE...AMIDST OVERALL WESTERN RIDGE/EASTERN TROUGH SCENARIO PERSISTING...AND WITH BROAD TROUGH PERSISTING INTO THE WEEKEND. AFTER FLURRY CHANCES MENTIONED WEDNESDAY...THE PREVIOUS FORECAST FOR CHANCE OF SNOW SHOWERS THEREAFTER IS HARD TO ARGUE WITH. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WINTER STORM WARNING...MIZ048-MIZ049-MIZ053-MIZ054-MIZ055- MIZ060-MIZ061-MIZ062-MIZ063-MIZ068-MIZ069-MIZ070...UNTIL NOON SUNDAY. SNOW AND BLOWING SNOW ADVISORY...MIZ047-MIZ075-MIZ076- MIZ082-MIZ083 UNTIL NOON SUNDAY. LAKE HURON...GALE WARNING...NEARSHORE AND OPEN WATERS FROM PORT AUSTIN TO PORT HURON INCLUDING SAGINAW BAY...UNTIL 1 AM MONDAY. LAKE ST CLAIR...GALE WARNING...UNTIL 1 AM MONDAY. MI WATERS OF LAKE ERIE...GALE WARNING...UNTIL 1 AM MONDAY. && $$ UPDATE.......DG AVIATION.....DG SHORT TERM...BRAVENDER LONG TERM....DWD YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1210 AM EST SUN FEB 5 2006 .UPDATE #2... UPDATED TO DOWNGRADE WAYNE COUNTY FROM A WARNING TO SNOW/BLOWING SNOW ADVISORY. FROTOGENETIC BANDING CONTINUES TO ROTATE BACK INTO THE CWA...WITH A NUMBER OF THE BANDS JUST MAKING IT INTO PARTS OF WAYNE COUNTY...BUT NO FURTHER. HEAVIEST SNOW...BY AND LARGE...WILL CONTINUE FROM M 59 NORTH INTO THE THUMB AND PARTS OF THE SAGINAW VALLEY...WHERE WARNING APPEARS IN VERY GOOD SHAPE WITH PLENTY OF REPORTS IN THE 5 TO 6 INCH RANGE ALREADY THIS EVENING. EDGED DOWN SNOW AMOUNTS SOUTH OF DETROIT...WITH NO MORE THAN 1-3 INCHES IN LENAWEE/MONROE (SOME WILL BE LUCKY TO GET THAT MUCH). && .UPDATE...ISSUED AT 825 PM UPDATED TO DOWNGRADE THE WARNING IN WASHTENAW...LENAWEE AND MONROE COUNTIES TO A SNOW/BLOWING SNOW ADVISORY WITH TEMPERATURES ABOVE FREEZING THIS EVENING...ACCUMULATION HAS BEEN HARD TO COME BY. THE MAIN SURGE OF MOISTURE IS NOW BACKING INTO THE AREA...AND WITH WITH TEMPERATURES NOW AROUND 33 AND FALLING...EXPECT ACCUMULATION TO COMMENCE. HOWEVER...THESE AREAS ARE ON THE SOUTHWESTERN EDGE OF THE BEST MOISTURE...SO DOUBT THEY WILL DO ANY BETTER THAN 3-5 INCHES OF SNOW...AND LIKELY LESS TOWARD THE OHIO BORDER. LEFT WAYNE COUNTY IN THE WARNING...ALTHOUGH MUCH OF THE COUNTY WILL FALL SHORT OF 6 INCHES GIVEN THE SLOW TURN OVER/ACCUMULATION. EVEN SO...THEY ARE ON THE PIVOT POINT OF THE AFOREMENTIONED SURGE OF MOISTURE...SO EXPECT A PRETTY TIGHT GRADIENT FROM NORTH TO SOUTH ACROSS THE COUNTY WITH THE NORTHERN BORDER PUSHING 5 OR 6 INCHES AND THE SOUTH CLOSER TO 3 MAYBE 4 INCHES BY SUNDAY MORNING. FURTHER NORTH...EXPANDED THE WARNING INTO THE SAGINAW VALLEY (BAY... SAGINAW AND SHIAWASSEE COUNTIES). TEMPERATURES HAVE FINALLY DROP TO FREEZING AND CONTINUE TO FALL. THE MAIN MOISTURE SURGE FROM THE SOUTHEAST IS POINTED RIGHT INTO THIS AREA. 18Z MODELS SUGGESTED 6-7 INCHES OF SNOW IN THE 00Z-12Z TIMEFRAME...AND RADAR/SATELLITE TRENDS NOW BARE THIS OUT. LEFT MIDLAND COUNTY AS AN ADVISORY BEING A BIT TOO FAR WEST. && .AVIATION...ISSUED AT 600 PM ALTHOUGH HEAVIER SNOWFALL HAS BEEN COMING IN POCKETS SO FAR...WITH SOME OF THE LIGHTER PERIODS STILL MIXED WITH RAIN...CONDITIONS WILL REMAIN IN THE IFR RANGE DUE TO LOW CEILINGS. 18Z MODELS ALL INSIST ON A RATHER IMPRESSIVE INCREASE IN SNOWFALL INTENSITY/COVERAGE BY 01/02Z...CARRYING ON THROUGH ABOUT 06-07Z. THERE AREA FINALLY SOME SIGNS OF THIS ON SATELLITE AS A STEADY ENHANCEMENT IN CLOUD FEATURES HAS BEEN ONGOING IN THE SOUTHEAST FEED OF MOISTURE OVER LAKE ERIE BACK TOWARD THE AREA. IN ADDITION...RADAR RETURNS HAVE RESPONDED IN THIS AREA. SO...STILL EXPECT A WINDOW OF MODERATE/HEAVY SNOW IN THE 01Z-05Z TIMEFRAME DTW/DET TRENDING INTO MBS BY 03Z-07Z. WILL TAPER THE SNOW OFF A BIT LATE TONIGHT...BUT KEEP VISIBILITIES DOWN IN THE 1-3SM MILE AREA WITH -SN/BLSN. SNOW WILL THEN TAPER OFF TO FLURRIES ON SUNDAY MORNING...W/ JUST BLSN IN GUSTY NORTHWEST FLOW PERSISTING IN THE AFTERNOON. && .SHORT TERM...TONIGHT AND SUNDAY...ISSUED AT 407 PM 12Z RAOBS/WATER VAPOR LOOP SHOW LONGWAVE TROUGH FROM THE GREAT LAKES TO THE GULF COAST. STRONG SHORTWAVE LIFTING INTO OHIO...WITH SECONDARY ENERGY OVER WISCONSIN/ILLINOIS. WATER VAPOR/HEIGHT ANALYSIS ALREADY SHOWS SIGNS OF CUTTING OFF AS THE SYSTEM WRAPS UP. 18Z ACARS OBSERVATIONS AROUND 30KFT SHOW A WIDESPREAD AREA OF +150KTS...WITH ONE REPORT OF 175KTS. SURFACE ANALYSIS SHOWS LOW OVER SOUTHEASTERN OHIO...WITH AN INCREASING AREA OF PRESSURE FALLS OVER CENTRAL LAKE ERIE. REGIONAL RADARS SHOW WIDESPREAD PRECIP ACROSS SOUTHEAST MICHIGAN. METARS ACROSS MUCH OF THE CWA HAVE CHANGED OVER TO SNOW...WITH CHANGE OVER WORKING ITS WAY FROM SOUTHEAST TO NORTHWEST. FEW STATIONS IN THE WESTERN AND NORTHERN CWA AWAY FROM THE HEAVIER PRECIP RATES STILL REPORTING RAIN. UPPER TROUGH TAKING ON A NEGATIVE TILT AS THE STRONG UPPER JET/SHORTWAVE LIFTS THROUGH THE OHIO VALLEY. SURFACE LOW CONTINUES TO TAKE A MORE LEFT/NORTHWARD TURN AS WELL...LEADING TO A CONTINUATION OF THE EARLIER WESTWARD TREND AND OVERALL IN LINE WITH THE GOING FORECAST. COMPARED TO 18Z ACARS OBSERVATIONS...12Z RUNS STILL UNDERDO THE STRENGTH OF THE DOWNSTREAM JET...BY ABOUT 6 HOURS AND AT LEAST 10KTS. THIS SHOULD LEAD TO A CONTINUED STRENGTHENING OF THE SURFACE LOW...WITH A FASTER TRACK INTO ONTARIO TONIGHT. THIS COULD LEAD TO A SHORTER PERIOD OF SNOW ACROSS THE SOUTHWESTERN CWA. GOOD MOISTURE FLUX AND FRONTOGENESIS TO THE NORTHWEST OF THE SYSTEM LEADING TO WIDESPREAD PRECIP AND MODEST SNOWFALL RATES ALREADY. SPOTTER REPORTS FROM DTX/PTK SOUTHWARD INDICATE SNOW IS BEGINNING TO ACCUMULATE...WITH UP TO HALF INCH IN 45 MINUTES REPORTED. TAMDAR SOUNDINGS INTO DTW SHOW THE PROFILE ALL BELOW FREEZING...WITH SOUNDINGS FARTHER NORTH AND WEST STILL SHOW FREEZING LEVELS >1.2KFT. ONCE HEAVIER PRECIP MAKES IT NORTHWESTWARD...EXPECT MELTING AND DYNAMIC COOLING TO ALLOW PRECIP TO QUICKLY CHANGE OVER TO ALL SNOW. ONE ADDITIONAL CONCERN IS WITH CONVECTIVE POTENTIAL ACROSS THE SOUTHERN CWA. 18Z RUC CROSS SECTIONS SHOWS WEAK TO NEUTRAL STATIC STABILITY...WHILE THE 12Z NAM IS ACTUALLY CONVECTIVELY UNSTABLE WITH THETA-E FOLDED OVER. LDN ACTUALLY PICKED UP A COUPLE LIGHTNING STRIKES OVER WESTERN LAKE ERIE AND NEAR TOLEDO. AM TEMPTED TO HOLD OFF ON MENTIONING THUNDER AS THE NAM WINDOW OF INSTABILITY IS PRETTY SHORT AND DIMINISHES AFTER 21Z. COULD SEE SOME HEAVY PRECIP RATES THOUGH...AS CAN BE INFERRED FROM SNOW THAT IS ALREADY ACCUMULATING ACROSS THE SOUTHERN CWA. THE FASTER TREND MAY LIMIT THE DURATION OF SNOWFALL ACROSS THE FAR SOUTHWEST...AS THE SYSTEM PULLS OUT FASTER. HOWEVER EXPECT THE SNOWFALL RATES THIS EVENING WITH WEAK STABILITY TO HELP US REALIZE THE WARNING CRITERIA SNOWFALL...AND THEREFORE WILL KEEP THE WARNING GOING. THE WESTWARD TREND WOULD ALLOW THE TROWAL TO SETUP FARTHER WEST AND NORTH ACROSS THE THUMB AND INTO NORTHERN LOWER. WILL BUMP SNOW ACCUMULATIONS UP A BIT OVER TOWARD BAY COUNTY. HOWEVER GIVEN THE SLOWER CHANGEOVER AND QUESTIONABLE ENHANCEMENT THAT FAR WEST WILL KEEP THEM IN AN ADVISORY. ELSEWHERE SNOW TOTAL STILL LOOK GOOD...WITH GREATEST AMOUNT ACROSS THE THUMB WITH SOME ENHANCEMENT IN THE NORTHERLY FLOW OFF HURON. WILL MENTION DEFINITE BLOWING SNOW ACROSS THE CWA TONIGHT AS FORECAST SOUNDINGS/TIME SECTIONS SHOW THE MIXED LAYER TAPPING INTO 40KTS A FEW THOUSAND FEET OFF THE SURFACE. GOOD CYCLONIC FLOW ON SUNDAY WITH TRAILING SHORTWAVE SWINGING THOUGH. LAKE EFFECT SETUP IS NOT ALL THAT IMPRESSIVE...ALTHOUGH SOME SYNOPTIC LIFT WITH RELATIVELY DEEP MOISTURE PRESENT COULD LEAD TO SOME ENHANCEMENT. THEREFORE WILL HOLD ONTO LIKELY POPS AT LEAST THROUGH THE MORNING DESPITE A QUICKER DEPARTURE TO THE SYSTEM. ADDED AREA OF BLOWING SNOW AS WELL WITH A STRONG GRADIENT AND CONTINUED DEEP MIXED LAYER. && .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...ISSUED AT 407 PM WEEKEND SURFACE LOW SLOWLY RETREATING NORTHEAST THROUGH QUEBEC THROUGH EARLY PART OF WEEK AS ASSOCIATED CYCLONIC FLOW BACK ACROSS THE FORECAST AREA AND EASTERN GREAT LAKES REGION SLOWLY WANES. AT THE SAME TIME...THE CLOSED STACKED LOW ALOFT VERY SLOWLY RETREATING NORTH/NORTHEAST. AFTER MODEST DEEPER MOISTURE WANES SUNDAY NIGHT...ESPECIALLY SOUTH...THIS DEEPER MOISTURE RATHER MEAGER THROUGH EARLY PART OF WEEK. LOWER LEVEL RELATIVE HUMIDITIES...ON THE OTHER HAND...REMAIN GENERALLY HIGH THROUGH EARLY WEEK. DYNAMICS SLIGHT AT BEST FROM TIME TO TIME THROUGH EARLY WEEK...INCLUDING LOW TO MID LEVEL QVECTOR CONVERGENCE...SURFACE CONVERGENCE AND OMEGA LIFT. QPF FIELDS ALSO VERY LIGHT...AND NAM ESSENTIALLY EVEN DRY THROUGH TUESDAY. GFS MODEL SOUNDINGS SHOW BETTER LOW LEVEL MOISTURE THAN NAM... TAPPING COLDER THAN MINUS 10C TEMPERATURES FOR ICE NUCLEI...AND WITH NEARLY DRY ADIABATIC LOW LEVEL LAPSE RATES MUCH OF THE TIME WITH WEST TO NORTHWEST FLOW...HAVE MENTIONED AT LEAST FLURRY CHANCES THROUGH EARLY WEEK. DURING THE MID WEEK PERIOD INTO THE WEEKEND... MODELS SHOW SOME CONSENSUS TOWARD SURFACE RIDGING OVERHEAD WEDNESDAY...THEN CONSIDERABLE TIMING/DETAIL DIFFERENCES AMONG MODELS AS TO BRINGING OF CLIPPER ON DOWN INTO LAKES REGION...WHICH WHEN THIS DOES HAPPEN WILL BE ACCOMPANIED BY A RESURGENCE OF COLD ARCTIC AIR LATE NEXT WEEK. AT 500 MB...CONSIDERABLE DETAIL DIFFERENCES AMONG MODELS ESPECIALLY WITH RESPECT TO TIMING AND PLACEMENT OF INDIVIDUAL SHORTWAVE TROUGH IMPULSES...BUT MAIN IDEA IS FOR LOWERING HEIGHTS LATTER PART OF WEEK...AND WITH AVAILABLE MODELS SHOWING IMPROVED MOISTURE...AMIDST OVERALL WESTERN RIDGE/EASTERN TROUGH SCENARIO PERSISTING...AND WITH BROAD TROUGH PERSISTING INTO THE WEEKEND. AFTER FLURRY CHANCES MENTIONED WEDNESDAY...THE PREVIOUS FORECAST FOR CHANCE OF SNOW SHOWERS THEREAFTER IS HARD TO ARGUE WITH. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WINTER STORM WARNING...MIZ048-MIZ049-MIZ053-MIZ054-MIZ055- MIZ060-MIZ061-MIZ062-MIZ063-MIZ068-MIZ069-MIZ070...UNTIL NOON SUNDAY. SNOW AND BLOWING SNOW ADVISORY...MIZ047-MIZ075-MIZ076- MIZ082-MIZ083 UNTIL NOON SUNDAY. LAKE HURON...GALE WARNING...NEARSHORE AND OPEN WATERS FROM PORT AUSTIN TO PORT HURON INCLUDING SAGINAW BAY...UNTIL 1 AM MONDAY. LAKE ST CLAIR...GALE WARNING...UNTIL 1 AM MONDAY. MI WATERS OF LAKE ERIE...GALE WARNING...UNTIL 1 AM MONDAY. && $$ UPDATE.......DG AVIATION.....DG SHORT TERM...BRAVENDER LONG TERM....DWD YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 253 AM EST SUN FEB 5 2006 .SHORT TERM (TODAY THROUGH TUESDAY)... SURFACE ANALYSIS SHOWS DEEP SURFACE LOW JUST TO THE EAST OF TORONTO WITH CYCLONIC FLOW ACROSS FA. KILN RADAR SHOWS NUMEROUS LIGHT SNOW SHOWERS WORKING ACROSS FORECAST AREA. THESE SHOWERS ARE JUST AHEAD OF MID LEVEL WAVE WORKING WHICH IS WORKING CYCLONIC AROUND AN UPPER LOW CENTERED OVER OHIO. MODELS ARE IN PRETTY GOOD AGREEMENT WITH KEEPING REGION IN NORTHWESTERLY FLOW THROUGH MID WEEK. SURFACE LOW NEAR TORONTO WILL CONTINUE TO DRIFT NE BRINGING MORE NEUTRAL W/NWLY FLOW. WILL KEEP THREAT OF SNOW THIS MORNING WITH THE GREATEST THREAT ACROSS THE NORTH. ACCUMULATIONS WILL BE LESS THAN AN INCH. WILL DROP ALL HEADLINES WITH THIS ISSUANCE. NAM HOLDS ONTO LOW LEVEL MOISTURE THROUGH TONIGHT...ESPECIALLY ACROSS NORTHERN FA. PROGGED SOUNDINGS ALSO SUGGEST FREEZING DRIZZLE WILL BE POSSIBLE ACROSS THE NORTH. WILL MONITOR DEVELOPMENT BEFORE ADDING TO ZONES OR HOISTING AN ADVISORY. FORECAST IS THEN DRY WITH PARTLY CLOUDY SKIES. MAV TEMPS LOOK PRETTY GOOD WILL ONLY TWEAK A LITTLE HERE AND THERE. TIPTON && .LONG TERM (TUESDAY NIGHT THROUGH SATURDAY)... NO CHANGES MADE TO THE EXTENDED. FOR THOUGHTS OF PREVIOUS FORECASTER SEE BELOW. TIPTON && .AVIATION (06Z-06Z)... SFC LO NOW LOCATED ACRS SRN ONTARIO WITH UPR LO FOLLOWING CLOSELY IN ITS WAKE. PCPN PATTERN HAS TRANSITIONED TO MORE SCATTERED AND SHOWERY IN CYCLONIC FLO. -SHSN ALSO BEING ENHANCED BY MID LVL VORT DIVING ACRS INDIANA ATTM. 00Z GFS AND 03Z RUC BOTH HAVE STRENGTH AND LOCATION OF THIS FEATURE PEGGED WELL. VORT WILL SLOWLY DROP ACRS ERN INDIANA AND SRN OHIO THRU MID MRNG SUN...AND EXPECTA CONTINUATION OF SCT -SHSN FOR DURATION OF OVERNIGHT. ANY VSBY RESTRICTIONS SHOULD BE PRIMARILY LIMITED TO MVFR CAT BASED ON CURRENT OBS ACRS INDIANA. CIGS WILL HOVER BTWN 1000-1500FT ALL NIGHT. HAVE REMOVED -SHSN AFT MRNG HOURS FOR ALL BUT KCMH/KLCK AS LARGE AREA OF NVA REPLACES DEPARTING MID LVL VORT. SC DECK WILL SLOWLY LIFT DURING AFTN HOURS...AND MAY EVEN SCATTER OUT FOR A TIME SUN EVNG AT KCVG AND KLUK. ELSEWHERE...EXPECT SC DECK TO HOLD IN MVFR CAT THRU REMAINDER OF FCST PERIOD. MODEL SOUNDINGS INDCG BNDRY LYR INVERSION DVLPG DURING AFTN AND INTO SUN NIGHT...PARTICULARLY ACRS NRN 1/2 FCST AREA. AS DRIER AIR FILTERS INTO REGION OVER TOP OF INVERSION...COULD BE SOME POTENTIAL FOR -FZDZ AT KDAY/KCMH/KLCK SUN EVNG. HAVE MADE NO MENTION OF THIS IN TAFS...BUT WILL PASS THIS ONTO LATER SHIFTS TO MONITOR. WINDS WILL REMAIN GUSTY FROM THE WEST THRU MUCH OF THE FCST PERIOD. RYAN && .PREVIOUS DISCUSSION... (ISSUED 420 PM EST SAT FEB 4 2006) LONG TERM (MONDAY THROUGH SATURDAY)... LONG ADVERTISED PATTERN CHANGE STILL LOOKS TO BE ON TRACK AS BOTH THE GFS AND ECMWF INDICATING AMPLIFYING RIDGE ALONG THE WEST COAST THROUGH THE END OF THE WEEK. THIS WILL HELP CARVE OUT TROUGH ACROSS EASTERN US WITH MUCH COLDER AIRMASS SPILLING DOWN INTO AREA TOWARD NEXT WEEKEND. IN THE MEANTIME...SHORT WAVE ENERGY FORECAST TO DROP DOWN IN NORTHWEST FLOW ACROSS REGION WEDNESDAY INTO THURSDAY. MOISTURE LOOKS PRETTY LIMITED ACROSS OUR AREA AND WITH BETTER FORCING PASSING OFF TO THE SOUTH SO WILL GO WITH A DRY FORECAST THROUGH THURSDAY. AS UPPER LEVEL TROUGH DEEPENS FRIDAY INTO SATURDAY...AN ASSOCIATED SURFACE LOW WILL MOVE ACROSS GREAT LAKES WITH A COLD FRONT PUSHING DOWN THROUGH OUR AREA. AS DEEPER MOISTURE MOVES IN AND GOOD CYCLONIC FLOW DEVELOPS...WILL GO WITH A CHANCE OF SNOW SHOWERS FOR FRIDAY AND SATURDAY. UNDER PREDOMINANT NORTHWEST FLOW...WILL GENERALLY GO AT OR A LITTLE BELOW GUIDANCE FOR TEMPS EARLY IN THE LONG TERM AND SEVERAL DEGREES COLDER LATE IN THE PERIOD. EXCEPTION MAY BE FOR THURSDAY INTO THURSDAY NIGHT AS SOUTHERLY LOW LEVEL FLOW SHOULD DEVELOP AHEAD OF FRONT AND THIS MAY ALLOW FOR TEMPS A LITTLE WARMER THAN GUIDANCE DURING THAT TIME FRAME. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 1244 AM EST SUN FEB 5 2006 .AVIATION (06Z-06Z)... SFC LO NOW LOCATED ACRS SRN ONTARIO WITH UPR LO FOLLOWING CLOSELY IN ITS WAKE. PCPN PATTERN HAS TRANSITIONED TO MORE SCATTERED AND SHOWERY IN CYCLONIC FLO. -SHSN ALSO BEING ENHANCED BY MID LVL VORT DIVING ACRS INDIANA ATTM. 00Z GFS AND 03Z RUC BOTH HAVE STRENGTH AND LOCATION OF THIS FEATURE PEGGED WELL. VORT WILL SLOWLY DROP ACRS ERN INDIANA AND SRN OHIO THRU MID MRNG SUN...AND EXPECTA CONTINUATION OF SCT -SHSN FOR DURATION OF OVERNIGHT. ANY VSBY RESTRICTIONS SHOULD BE PRIMARILY LIMITED TO MVFR CAT BASED ON CURRENT OBS ACRS INDIANA. CIGS WILL HOVER BTWN 1000-1500FT ALL NIGHT. HAVE REMOVED -SHSN AFT MRNG HOURS FOR ALL BUT KCMH/KLCK AS LARGE AREA OF NVA REPLACES DEPARTING MID LVL VORT. SC DECK WILL SLOWLY LIFT DURING AFTN HOURS...AND MAY EVEN SCATTER OUT FOR A TIME SUN EVNG AT KCVG AND KLUK. ELSEWHERE...EXPECT SC DECK TO HOLD IN MVFR CAT THRU REMAINDER OF FCST PERIOD. MODEL SOUNDINGS INDCG BNDRY LYR INVERSION DVLPG DURING AFTN AND INTO SUN NIGHT...PARTICULARLY ACRS NRN 1/2 FCST AREA. AS DRIER AIR FILTERS INTO REGION OVER TOP OF INVERSION...COULD BE SOME POTENTIAL FOR -FZDZ AT KDAY/KCMH/KLCK SUN EVNG. HAVE MADE NO MENTION OF THIS IN TAFS...BUT WILL PASS THIS ONTO LATER SHIFTS TO MONITOR. WINDS WILL REMAIN GUSTY FROM THE WEST THRU MUCH OF THE FCST PERIOD. RYAN && .PREVIOUS DISCUSSION... (ISSUED 842 PM EST SAT FEB 4 2006) SHORT TERM (TONIGHT)... LATEST SFC MAP SHOWS DEEP SFC LOW OVER LAKE ERIE. AS THIS LOW LIFTS NE INTO ONTARIO CANADA AND DEPARTS THE REGION EXPECT SNOW TO CONT TO TAPER OFF TO WRAP AROUND SNOW SHOWERS. WITH DEEP MSTR AND LIFT DEPARTING EXPECT AN INCH OR LESS ADDITIONAL SNOW ACCUMULATION. HAVE GENERALLY OBSERVED 1 TO 3 INCHES ACROSS THE WEST AND AN INCH OR LESS IN THE EAST. THEREFORE HAVE DROPPED THE WINTER STORM WARNING AND REPLACED ALL HEADLINES WITH SNOW ADVISORY THRU 12Z SUNDAY. (ISSUED 420 PM EST SAT FEB 4 2006) SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)... CURRENT SURFACE ANALYSIS DEPICTS LOW PRESSURE OVER EASTERN OHIO THIS AFTERNOON. KILN RADAR SHOWS ENHANCED AREA OF SNOW PIVOTING NORTHEAST ACROSS THE CWA. THIS IS ASSOCIATED WITH MID LEVEL DEFORMATION ZONE. MODELS ARE IN FAIR AGREEMENT PIVOTING THIS DEFORMATION ZONE TO THE NORTHEAST THROUGH THE EVENING HOURS. 18Z ETA SHOWS A SECONDARY AREA OF DEFORMATION MOVING ACROSS THE NORTH AFTER 06Z. WITH THIS IN MIND HAVE KEPT CURRENT WSWS UP WITH CURRENT BREAKDOWN. BASED ON CURRENT RADAR TRENDS AND OBSERVATIONS HAVE BUMPED SNOW AMOUNTS SLIGHTLY DOWN...WITH 3 TO 5 ACROSS THE NORTHWEST AND 2 TO 4 ACROSS CENTRAL OHIO...AND 1 TO 3 ACROSS ADVISORY AREA. WINDS PICK UP ON THE BACK SIDE OF THE LOW...SO HAVE MENTIONED BLOWING SNOW IN AREAS THAT HAVE MORE ACCUMULATION. HAVE ALSO ADDED 20-30 POPS ON SUNDAY AS SOME DECENT MOISTURE REMAINS IN PLACE AND WEAK VORT ROTATES AROUND UPPER LOW. STAYED NEAR GUIDANCE FOR TEMPS. WENT A LITTLE BELOW GUIDANCE ON SUNDAY WITH SOME SNOW COVER. RLG (ISSUED 420 PM EST SAT FEB 4 2006) LONG TERM (MONDAY THROUGH SATURDAY)... LONG ADVERTISED PATTERN CHANGE STILL LOOKS TO BE ON TRACK AS BOTH THE GFS AND ECMWF INDICATING AMPLIFYING RIDGE ALONG THE WEST COAST THROUGH THE END OF THE WEEK. THIS WILL HELP CARVE OUT TROUGH ACROSS EASTERN US WITH MUCH COLDER AIRMASS SPILLING DOWN INTO AREA TOWARD NEXT WEEKEND. IN THE MEANTIME...SHORT WAVE ENERGY FORECAST TO DROP DOWN IN NORTHWEST FLOW ACROSS REGION WEDNESDAY INTO THURSDAY. MOISTURE LOOKS PRETTY LIMITED ACROSS OUR AREA AND WITH BETTER FORCING PASSING OFF TO THE SOUTH SO WILL GO WITH A DRY FORECAST THROUGH THURSDAY. AS UPPER LEVEL TROUGH DEEPENS FRIDAY INTO SATURDAY...AN ASSOCIATED SURFACE LOW WILL MOVE ACROSS GREAT LAKES WITH A COLD FRONT PUSHING DOWN THROUGH OUR AREA. AS DEEPER MOISTURE MOVES IN AND GOOD CYCLONIC FLOW DEVELOPS...WILL GO WITH A CHANCE OF SNOW SHOWERS FOR FRIDAY AND SATURDAY. UNDER PREDOMINANT NORTHWEST FLOW...WILL GENERALLY GO AT OR A LITTLE BELOW GUIDANCE FOR TEMPS EARLY IN THE LONG TERM AND SEVERAL DEGREES COLDER LATE IN THE PERIOD. EXCEPTION MAY BE FOR THURSDAY INTO THURSDAY NIGHT AS SOUTHERLY LOW LEVEL FLOW SHOULD DEVELOP AHEAD OF FRONT AND THIS MAY ALLOW FOR TEMPS A LITTLE WARMER THAN GUIDANCE DURING THAT TIME FRAME. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...SNOW ADVISORY FOR OHZ026-034-035-042>046-051>056-060>065- 070>074-077>082-088 UNTIL 7 AM SUNDAY. KY...SNOW ADVISORY FOR KYZ089>100 UNTIL 7 AM SUNDAY. IN...SNOW ADVISORY FOR INZ050-058-059-066-073>075-080 UNTIL 7 AM SUNDAY. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 1055 AM EST SUN FEB 5 2006 .MORNING UPDATE... UPDATED GRIDS MAINLY JUST TO TAKE MORNING WORDING OUT OF THE ZONES. REMOVED FLURRY WORDING TOO...ALTHOUGH A STRAY FLURRY WILL BE POSSIBLE ACROSS MAINLY THE BLUEGRASS REGION OF KENTUCKY GIVEN THE STEEP LOW-LEVEL LAPSE RATES. HOWEVER...THIS LIGHT ACTIVITY SHOULD END SHORTLY AS IT CONTINUES OFF TO THE NE. LIFR CEILINGS NOTED IN SE IL AND MUCH OF IN. THIS IS MOVING TO THE SOUTHEAST. SO ALTHOUGH THERE MAY BE A SMALL WINDOW OF CLEARING ACROSS MY SWRN CWA...NEAR BOWLING GREEN AND SURROUNDING COMMUNITIES...I EXPECT THAT THESE LOW CLOUDS WILL CONTINUE TO FILTER INTO THE REGION...WHICH IS SUPPORTED BY THE NAM AND RUC LOW-LEVEL MOISTURE FIELDS. THESE CLOUDS SHOULD ERODE TOWARD EVENING AND MAY PROVIDE SOME AREAS WITH A GLIMPSE OR TWO OF SUNSHINE. HIGHER CLOUDS FROM A DEVELOPING SYSTEM IN THE PLAINS WILL SKIRT THE SWRN CWA LATER THIS AFTERNOON...BUT SHOULD POSE NO OTHER THREAT. WITH CLOUDY SKIES AND SNOW COVER...HAVE LOWERED MAX TEMPS A DEGREE OR TWO. THINK BLUEGRASS REGION WILL HAVE TROUBLE REACHING 30...SO HAVE LOWERED THE HIGHS TO RIGHT AROUND THERE. A NICE DAY TO STAY INDOORS AND ENJOY THE SUPERBOWL THIS EVENING. UPDATE OUT SHORTLY. AL && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 1220 PM CST SUN FEB 5 2006 .UPDATE... OVERNIGHT MODELS APPRD TO HAVE BEEN OVERLY AGRESSIVE IN SATURATING VERY DRY AIR MASS...AND 1200 UTC RUNS SEEM TO BE FOLLOWING SUIT GIVEN CURRENT SATELLITE IMAGES. HAVE TRIMMED BACK ON THE CLOUDS/PRECIPITATION FOR BOTH THIS AFTERNOON/EVENING. WITH MORE SUNSHINE...BOTH WINDS/TEMPERATURES HIGHER THAN INITIALLY FORECAST. TEMPERATURES ALONG THE OK BORDER SHOULD BREAK INTO THE 50S. WARM TEMPERATURES ALSO SUGGEST ANY SORT OF FROZEN PRECIPITATION WILL OCCUR LATER THAN INITIALLY ADVERTISED. DYNAMICS ARE NOT THAT IMPRESSIVE WITH THIS SYSTEM AND LACK OF BAROCLINICITY AND WARM AIR ADVECTION FURTHER SUPPORT LOW PROBABILITY OF PRECIPITATION/TRACE EVENT. MADE SOME TWEAKS TO EVENING/OVERNIGHT PART TO BLEND BETTER WITH AFTERNOON FORECAST...AND SUSPECT AFTERNOON PACKAGE WILL FURTHER REFINE PROBABILITY OF PRECIPITATION AND PRECIPITATION TYPE. GRIDS/PRODUCTS ALREADY UPDATED. -HOWERTON && .PREV DISCUSSION... /ISSUED 318 AM CST SUN FEB 5 2006/ DISCUSSION... MAIN CONCERN WITH THIS FORECAST PACKAGE WILL BE THE CHANCE OF SNOW TODAY AND HOW MUCH ACCUMULATION IS POSSIBLE. TODAY: LATEST WATER VAPOR LOOP SHOWING THE UPPER LEVEL WAVE MOVING ACROSS THE ROCKIES. THE VORT LOBE ASSOCIATED WITH THIS FEATURE APPEARS TO BE NEAR THE UTAH/COLORADO BORDER. RIGHT NOW...IT DOES NOT APPEAR LIKE THIS FEATURE IS DIGGING THAT MUCH...BUT THERE IS A HINT OF DRY SLOT TRYING TO REDEVELOP OVER WESTERN COLORADO. THE RUC APPEARS TO HAVE THE SURFACE LOW PLACED TO FAR EAST...SO THIS WAVE MAY END UP COMING THROUGH A LITTLE SLOWER THAN PROGGED. WE ARE CONTINUING TO PLAY THE CONSERVATIVE ROUTE ON POPS THIS AFTERNOON AND TONIGHT. THE NAM DOES SHOW THE THETA SURFACES REALLY RISING BETWEEN 280-290K DURING THE AFTERNOON. THIS WILL HELP SATURATE THINGS UP FAIRLY QUICKLY. THERE IS EVEN A HINT OF MID LEVEL INSTABILITY WHEN THIS MID LEVEL COLD POCKET MOVES THROUGH LATE THIS AFTERNOON AND EVENING. COBB OUTPUT FROM THE ETA IS NOT SHOWING ANY SNOW ACCUMULATION AT ALL THIS EVENING, BUT THE GFS IS SHOWING BETWEEN 0.5 AND 1 INCH AROUND CHANUTE. THIS MAY BE A BIT OVERDONE...SINCE THIS WAVE LOOKS TO BE STARVED FOR MOISTURE...EVEN THOUGH THE DYNAMICS LOOK GOOD. WE ARE NOT GOING TO MAKE MANY CHANGES AT THIS TIME...BUT WE MAY ADD THE POTENTIAL FOR SOME FREEZING DRIZZLE MAINLY WEST OF THE I-35/135 CORRIDOR TONIGHT DUE TO A LOW LEVEL COLD POCKET AROUND 280K MOVING THROUGH THE REGION. WE ARE NOT GOING TO MENTION ANY HEADLINE SINCE IT LOOKS LIKE THIS DRIZZLE WILL BE PATCHY IN NATURE WHICH SHOULD KEEP MOST OF THE ROADWAYS IN GOOD SHAPE. DOWNGLIDE WILL ALSO BE TAKING OVER AFTER MIDNIGHT. LOW IFR CEILINGS MAY ALSO BE A PROBLEM ACROSS THE I-35/135 CORRIDOR AFTER 03Z AND CONTINUE OVERNIGHT. WE DID RAISE TEMPERATURES SLIGHTLY ACROSS SOUTH CENTRAL AND SOUTHEAST KANSAS TODAY...BUT THE CLOUDS SHOULD KEEP THEM DOWN. FORECAST CONFIDENCE IS ON THE LOW END OF HIGH. SUNDAY NIGHT-TUESDAY: NO REAL BIG CHANGES DURING THIS TIMEFRAME AS SURFACE HIGH PRESSURE BUILDS IN FROM THE ROCKIES. THE UPPER LEVEL PATTERN ALSO DOES NOT SHOW MUCH OF A CHANGE EITHER WITH THE POSITION OF THE TROF IN THE EAST. THIS WILL ALLOW FOR A CANADIAN CLIPPER TO PASS THROUGH REGION TUESDAY. THIS SYSTEM WILL ALSO BE MOISTURE STARVED. THEREFORE...WE WILL NOT BE ADDING POPS DURING THIS TIMEFRAME. FORECAST CONFIDENCE IS IN THE MEDIUM RANGE. WEDNESDAY-SATURDAY: WE ARE NOT MAKING A WHOLE LOT OF CHANGES TO THIS PORTION OF THE FORECAST PACKAGE EITHER. THE ECMWF CONTINUES TO BE FAIRLY CONSISTENT WITH THE TROF DEEPENING ACROSS THE EAST WHICH WILL ALLOW FOR MORE POLAR AIR TO ENTER THE REGION FRIDAY AND SATURDAY. THE GFS TENDS TO AGREE MORE WITH THE UKMET AND IS TENDING TO FLIP FLOP A LITTLE ON THE COLD AIR. HOWEVER...THEY ARE ALL SHOWING A COLD POLAR HIGH DROPPING INTO THE REGION WHICH WILL ALLOW TEMPERATURES TO DROP BELOW SEASONABLE NORMS. WE DID TWEAK TEMPERATURES DOWN A DEGREE OR TWO ON FRIDAY...BUT IT STILL LOOKS DRY DUE TO LACK OF GOOD MOISTURE FETCH. FORECAST CONFIDENCE IS MEDIUM. COX && PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 47 23 47 23 / 10 20 0 0 HUTCHINSON 46 23 47 23 / 20 20 0 0 NEWTON 45 23 46 23 / 20 20 0 0 ELDORADO 45 23 47 23 / 10 30 5 0 WINFIELD-KWLD 48 24 48 23 / 10 20 0 0 RUSSELL 42 22 46 22 / 20 20 0 0 GREAT BEND 45 22 46 22 / 20 20 0 0 SALINA 42 22 45 22 / 20 20 0 0 MCPHERSON 45 22 46 22 / 20 20 0 0 COFFEYVILLE 45 24 47 24 / 10 30 10 0 CHANUTE 42 24 46 23 / 10 30 10 0 IOLA 42 24 45 23 / 10 30 5 0 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 235 PM EST SUN FEB 5 2006 .DISCUSSION... TROF OF LOW PRESSURE WILL REMAIN ACROSS THE ERN US THROUGH THE PERIOD ENSURING BELOW NORMAL TEMPS. S/WS WILL DROP SE IN THE NW FLOW FROM TIME TO TIME BUT MOISTURE WILL BE LACKING AND ANY PCPN PRODUCED WILL BE LIGHT. SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...BENIGN WEATHER PATTERN WILL BE IN PLACE THROUGH THE SHORT TERM. LOW CLOUDINESS WILL BE SLOW TO RETREAT TONIGHT ESPECIALLY ACROSS THE NE SO WILL GO A LITTLE MORE PESSIMISTIC ON SKY COVER AND BASE THE GRIDS OFF OF THE RUC40 MOISTURE FIELDS. CIGS SHOULD BRAKE EVEN UP N HOWEVER BY SHORTLY AFTER MIDNIGHT. THERE MAY BE A FLURRY OR TWO OVER THE NE COUNTIES EARLY THIS EVENING BUT THESE WILL BE FEW AND FAR BETWEEN. A S/W WILL SWING ACROSS THE TN VALLEY MON AND MON NIGHT CAUSING CYCLOGENESIS OVER THE DEEP S. THIS SYSTEM WILL BE TOO FAR S TO HAVE MUCH OF AN IMPACT ON THE JKL CWA. ANOTHER WEAK AND MOISTURE STARVED VORT SWINGS ACROSS ON TUE BUT JUST SOME MID AND HI CLOUDS ARE EXPECTED FROM THIS. GENERALLY FOLLOWED THE COOLER GUIDANCE NUMBERS THROUGH THE PERIOD. CLEARING SKIES TONIGHT SHOULD HELP NUMBERS DROP OFF ESPECIALLY IN THE SHELTERED VALLEYS OUT W AND LOW DEWS AND FAIR SKIES MON NIGHT AND TUE NIGHT SHOULD HELP TEMPS FALL TO OR BELOW COOLER GUIDANCE NUMBERS EACH NIGHT...ESPECIALLY IN THE SHELTERED VALLEYS. MAV GUIDANCE MAX TEMPS ON MON AND TUE SEEMED TOO HIGH W/ H85 TEMPS ONLY REBOUNDING INTO THE -6C TO -5C RANGE DURING THOSE PERIODS... SUPPORTING MAX TEMPS IN THE 40F TO 45F RANGE W/ FULL SUNSHINE. EXTENDED (WEDNESDAY THROUGH SUNDAY)...WED WILL START OUT WITH A PLAINS RIDGE AND AN EAST COAST TROF. THIS PATTERN PLACES ERN KY IN NRLY FLOW AND DRY. THE COLD NORTH FLOW WILL KEEP TEMPS SUPPRESSED AS HIGHS WILL FLIRT WITH THE FREEZING MARK THROUGHOUT THE EXTENDED PERIOD. MEANWHILE LOWS WILL RANGE FROM THE UPPER TEENS TO THE MID 20S. HAVE FOLLOWED THE EXTENDED GFS FOR THIS FCST AS A CANADIAN VORTEX BRUSHES THE CWFA ON FRI BUT BRINGS LITTLE MOISTURE OUT OF THE CANADIAN PLAINS SO EXPECTING LOW POPS. OTHERWISE...A SERIES OF CLIPPER S/WV WILL PLUNGE INTO THE ERN TROF TO REINFORCE THE PATTERN WHILE DOING LITTLE TO BRING APPRECIABLE PCPN TO ERN KY. && .PREV DISCUSSION... 1030 AM EST SUN FEB 5 2006 GENERALLY A 1 TO 2 INCH SNOWFALL OVERNIGHT LAST NIGHT ACROSS THE COALFIELDS AND ERN BLUEGRASS REGION W/ A 2 TO 4 INCH SWATCH OVER BATH AND FLEMING COS. WHERE HEAVIER BAND SETUP YESTERDAY AFTERNOON. SEE PNSJKL FOR A ROUNDUP OF AREA SNOWFALL OBS. MID MORNING SURFACE AND H85 HAND ANALYSES REVEAL COLDEST AIR ALOFT ASSOCIATED W/ H85 TROF CENTERED OVER THE JKL CWA W/ TEMPS AROUND -12C. THE ARCTIC FRONT IS POSITIONED OVER EXTREME SE IL AND IN AND THIS IS PAIRED W/ A WEAK H85 REFLECTION WHICH SHOWS UP WELL ON THE CHART...W WINDS NOTED OVER LOU BUT NW WINDS REPORTED AT ILX...AND ON THE VIZ SAT IMAGERY...BAND OF MVFR SC STRETCHING FROM SRN IL INTO NW KY. SR MODELS ARE NOT HANDLING THIS FEATURE WELL AND BELIEVE AS IT CONTINUES SE SLOWLY INTO ERN KY THIS AFTERNOON IT WILL CONTINUE TO PRODUCE A FEW SNOW SHOWERS ALONG W/ CONSIDERABLE CLOUD COVER. WILL UPDATE PRODUCTS THIS MORNING TO CONTINUE SOME POPS INTO THE AFTERNOON HOURS ACROSS THE NE TWO-THIRDS OF THE CWA. SOME BINOVC STILL APPEAR LIKELY OVER THE SW THIRD BUT STILL CAN/T RULE OUT A FLURRY THERE THRU THE AFTERNOON HOURS IN THIS STEEP LAPSE RATE ENVIRONMENT. TEMPS LOOK GOOD THIS AFTERNOON W/ CAA AND EXTENSIVE CLOUD COVER RESULTING IN A MINIMAL RISE. UPDATED PRODUCTS WILL BE SENT ALONG ONCE FINALIZED. HAVE A GOOD DAY...AND ENJOY THE SNOW! 425 AM EST SUN FEB 5 2006 SHORT TERM (TODAY THROUGH TUESDAY)... SHORTWAVE CURRENTLY MOVING ACROSS SOUTHERN INDIANA. ONCE THE SHORTWAVE MOVES THROUGH...ONLY EXPECT LIGHT SNOW SHOWERS. CANCELED THE SNOW ADVISORY A LITTLE EARLY WITH ONLY LIGHT ACCUMULATIONS FOR TODAY. A FEW RIDGETOPS IN FAR SOUTHEASTERN KY MAY STILL SEE UP TO AN INCH...BUT NOT WIDESPREAD ENOUGH TO WARRANT KEEPING THE ADVISORY. HAD A FEW REPORTS EARLIER OF 2 INCHES ON THE HIGHER TERRAIN OF HARLAN COUNTY AND ON THE RIDGES IN OWSLEY AND PERRY COUNTIES. SOUNDINGS INDICATE MOSTLY CLOUDY SKIES FOR TODAY AND SKIES SCATTERING OUT TONIGHT. SNOW SHOWERS WILL TAPER OFF TO FLURRIES TODAY...AS FLOW BECOMES MORE WEST/SOUTHWEST AND DRIER AIR MOVES INTO THE REGION THIS AFTERNOON AND EVENING. DRY CONDITIONS ARE IN STORE FOR THE NEXT FEW DAYS WITH WEAK RIDGING AT THE SFC. GFS AND ETA BOTH KEEP A DEVELOPING SYSTEM WELL SOUTH OF THE AREA ON MONDAY AND TUESDAY. MAIN CHALLENGE AFTER THE SNOW DEPARTS TODAY IS TEMPERATURES. MAV NUMBERS ARE WARMER FOR THE SHORT TERM. WITH WEST/NORTHWESTERLY FLOW OVER THE AREA FOR THE SHORT TERM...DECIDED TO GO WITH THE COOLER MET NUMBERS. SOUNDINGS INDICATE A SMALL RIDGE/VALLEY SPLIT THE NEXT FEW NIGHTS. ADDED A RANGE OR A SMALL RIDGE/VALLEY SPLIT FOR LOWS TONIGHT AND MONDAY NIGHT WHERE NEEDED IN THE ZONES. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE && $$ ABE/DUSTY ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 348 PM EST SUN FEB 5 2006 .DISCUSSION... MAIN FORECAST CONCERNS ARE SNOW AMOUNTS EAST OF MARQUETTE AND IMPACT OF DRY AIR ELSEWERE. CURRENT WEATHER...20Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED AN UPPER LOW OVER SE ONTARIO. MUCH OF THE WESTERN GREAT LAKES INTO THE MID-ATLANTIC INTO THE NORTHEAST ARE UNDER LOWER HEIGHTS ASSOCIATED WITH THE UPPER LOW. THIS UPPER LOW IS ALSO VERTICALLY STACKED AS A 981MB SURFACE LOW EXISTS BENEATH THE 500MB LOW. DEEP MOISTURE CONTINUES TO CIRCULATE AROUND THE LOW...WITH THE WESTERN EDGE EAST OF A LINE FROM STANNARD ROCK TO ESCANABA PER SATELLITE IMAGERY. SOME LAKE EFFECT/LAKE ENHANCED SNOW CONTINUES UNDER THIS DEEPER MOISTURE ON KMQT RADAR IMAGERY. SNOWFALL AMOUNTS AT LEAST UP TO NOON WERE AS HIGH AS 4-5 INCHES...PARTICULARLY OVER NEWBERRY. OVER MARQUETTE AND ALGER COUNTIES...ONLY AN INCH OR TWO HAS OCCURRED SO FAR FROM THE LAKE EFFECT. THE BIGGER CONCERN HAS BEEN BLOWING SNOW DUE TO GUSTY WINDS OF 30-40 MPH. WHERE DEEPER MOISTURE DOES NOT EXIST...THE LAKE EFFECT BANDS AND CLOUDS HAVE COMPLETELY COLLAPSED. THIS IS DUE TO VERY DRY AIR CROSSING THE LAKE AS SEEN BY THE 12Z KINL SOUNDING AND 18Z TAMDAR SOUNDING. IN FACT...RELATIVE HUMIDITIES ALONG THE MINNESOTA ARROWHEAD HAVE DROPPED INTO THE TEENS AS TEMPERATURE DEWPOINT SPREADS ARE 30-40 F. ALL OF THE CLEAR SKIES THAT ARE PRESENT ARE ASSOCIATED WITH A 1024MB AREA OF HIGH PRESSURE OVER MINNESOTA. FARTHER TO THE WEST...A WEAK UPPER LEVEL RIDGE WAS PRESENT ACROSS THE NORTHERN PLAINS AND A STRONGER RIDGE WAS MOVING INTO THE WEST COAST. A COUPLE OF WEAKENING SHRTWVS EXIST BETWEEN THESE TWO RIDGES. UPPER AND SURFACE LOWS ARE PROGGED TO MOVE SLOWLY TO THE NE TONIGHT WHILE A SHRTWV CURRENTLY OVER NORTHERN ONTARIO DROPS SOUTH ACROSS LAKE SUPERIOR. THIS SHRTWV MAY HELP RAISE INVERSION HEIGHTS AS IT CROSSES THE EASTERN LAKE SUPERIOR. WITH DECENT MOISTURE AROUND...BOTH FROM LAKE EFFECT AND SYNOPTIC...AND UPSLOPE LOW LEVEL NORTHWESTERLY FLOW...A GOOD SETUP EXISTS FOR PLENTY OF SNOWFALL FROM THE PICTURED ROCKS EASTWARD. NEW 18Z NAM SEEMS TO HAVE A GOOD HANDLE ON THE CURRENT SITUATION AND SHOWS SNOW INTENSIFYING THROUGH THE NIGHT...AS IT DID LAST NIGHT. QPF AMOUNTS OF 0.40-0.50 ARE SUGGESTED FOR TONIGHT...WHICH WOULD YIELD ABOUT 8 INCHES USING A 20 TO 1 RATIO...COMMON FOR LAKE EFFECT. SINCE NEWBERRY HAS ALREADY PICKED UP NEAR WARNING AMOUNTS BY NOW (MANY HOURS OF 1/2SM OR LESS VSBY AT NEWBERRY SINCE NOON)...WILL ISSUE A LAKE EFFECT SNOW WARNING FOR LUCE AND ADJACENT AREAS OF EASTERN ALGER AND NORTHERN SCHOOLCRAFT COUNTIES. STRONG WINDS SHOULD EVEN PUSH SOME OF THE SNOW INTO SOUTHERN SCHOOLCRAFT COUNTY AND WITH THE WINDY CONDITIONS...HAVE OPTED TO PUT OUT A LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY FOR THAT AREA. SNOW LOOKS TO CONTINUE INTO THE DAY ON MONDAY WITH UP TO ANOTHER 0.25 INCH POSSIBLE IN UPSLOPE AREAS OF THE EASTERN U.P. ELSEWHERE...DRY AIR IS HAVING A MAJOR IMPACT ON THE WEATHER. THERE IS SOME CONCERN THAT WITH DIURNAL COOLING...LAKE EFFECT COULD GET GOING AGAIN...BUT SATELLITE PICTURES AND FORECAST SOUNDINGS SUGGEST THAT IT IS UNLIKELY. THEREFORE HAVE MADE SOME MAJOR CHANGES TO DROP A LOT OF THE WEATHER IN THE CURRENT GRIDS THROUGH MONDAY...EXCEPT FOR BLOWING SNOW WHICH PERSISTS OVER THE KEWEENAW. WITH THE CLEARING SKIES...SOME CONCERN EXISTS FOR TEMPERATURES...HOWEVER PLENTY OF WIND TONIGHT SHOULD PREVENT TEMPS FROM DROPPING BELOW ZERO. GALE WARNINGS CONTINUE ON THE EASTERN 2/3 OF LAKE SUPERIOR AS STDM4 HAS HAD GALES ALL DAY AND MODELS SHOW WINDS STAYING NEARLY THE SAME OR INCREASING SLIGHTLY TONIGHT. FOR MONDAY NIGHT AND TUESDAY...UPPER AND SURFACE LOWS CONTINUE THEIR NORTHEASTWARD PROGRESSION ACROSS QUEBEC AS HIGH PRESSURE BEGINS BUILDING SOUTH FROM CANADA. 850MB TEMPS REMAIN AROUND -13C THROUGH THIS PERIOD...WHICH WOULD NORMALLY SUGGEST LAKE EFFECT...BUT WITH SO MUCH DRY AIR ALREADY PRESENT IN THE LOW LEVELS...HAVE TAKEN MUCH OF IT OUT. THE ONLY PLACE WHERE LAKE EFFECT CHANCES PERSIST IS OVER THE EASTERN U.P. WHERE THE LONG FETCH OF NORTHERLY WINDS CAN DRAW THE MOST MOISTURE OFF LAKE SUPERIOR. ACCUMULATIONS ARE EXPECTED TO BE LIGHT THOUGH. TEMPERATURES FOR MONDAY NIGHT ARE AGAIN A CONCERN...AND HAVE DROPPED LOWS A FEW DEGREES IN THE INTERIOR AS WINDS ARE PROGGED TO BE A BIT LIGHTER. TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...GFS/NAM/UKMET/ECMWF ALL SHOW THE HIGH PRESSURE MOVING SOUTHWARD INTO MINNESOTA BY 12Z WED AND REMAIN NEARLY STATIONARY THROUGH 00Z THU. RH FORECASTS SHOW EVEN DRIER AIR MOVING IN WITH THIS HIGH...WHICH MAKES SENSE FROM ITS SOURCE REGION. THEREFORE HAVE SOME LAKE EFFECT FLURRIES/CLOUDS PERSISTING OVER THE EASTERN U.P. TUESDAY NIGHT INTO WEDNESDAY MORNING...THEN HAVE THEM ENDING. TEMPERATURES CONTINUE TO BE TRICKY AND HAVE LOWS NEAR ZERO TUESDAY NIGHT AND WEDNESDAY NIGHT. THESE MAY NEED TO BE LOWERED IN LATER FORECASTS IF THE HIGH/MID CLOUDS PREDICTED BY THE NAM/GFS DO NOT PAN OUT. WEDNESDAY\S HIGHS SHOULD END UP WARMER AS 850MB TEMPS CLIMB. EXTENDED (THURSDAY THROUGH SUNDAY)...GLOBAL MODELS REMAIN FAIRLY SIMILAR TO YESTERDAY SHOWING A POSITIVE PNA PATTERN DEVELOPING EARLY IN THIS PERIOD...THANKS TO A STRONG SYSTEM THAT COMES OUT OF THE NE PACIFIC ON TUESDAY. THE PATTERN IS VERY FAVORABLE FOR LAKE EFFECT AS COLD AIR DROPS SOUTH INTO THE UPPER LEVEL TROUGH OVER EASTERN NORTH AMERICA. THERE ARE A FEW DIFFERENCES TO NOTE WHICH MAKE SOME OF THE EXTENDED FORECAST TROUBLESOME. THE DIFFERENCES START OFF WITH WHERE THE SYSTEM THAT COMES OUT OF THE NE PACIFIC. THE 12Z ECMWF FROM YESTERDAY AND NOW THE 00Z ECMWF SHOW IT DIGGING MORE INTO THE NORTHERN PLAINS...WITH THE SURFACE LOW TRACKING ACROSS THE U.P. THURSDAY NIGHT. THIS TRACK WOULD BE A GOOD TRACK FOR A DECENT SNOW EVENT ACROSS THE CWA...ESPECIALLY IF IT WENT SLIGHTLY FARTHER SOUTH. HOWEVER...THE PAST FEW CANADIAN...UKMET AND GFS RUNS CONTINUE TO SHOW A TRACK ACROSS NORTHERN ONTARIO. HARD TO SAY WHICH SOLUTION WILL END UP CORRECT AT THIS POINT GIVEN THE STRONG NATURE OF THE SYSTEM. NEW 12Z GFS LOOKS SIMILAR TO THE ECMWF RUNS NOW SO WILL TREND TOWARDS THIS IDEA. NO MATTER WHAT HAPPENS WITH THE THURSDAY TRACK...ALL MODELS SHOW THE COLD FRONT ASSOCIATED WITH THE LOW CROSSING THE CWA ON FRIDAY...WITH 850MB TEMPS FALLING BELOW -12C. THEREFORE LAKE EFFECT SNOW SHOULD IMMEDIATELY FORM BEHIND THE FRONT. EXPECT THE LAKE EFFECT SNOW TO CONTINUE THROUGH SATURDAY AS NORTH/NORTHWESTERLY FLOW PERSISTS UNDER THE UPPER LEVEL TROUGH. 00Z ECMWF THEN SHOWS LOW LEVEL FLOW BACKING MORE WESTERLY ON SATURDAY NIGHT AS THE WESTERN RIDGE AMPLIFIES MORE. ON THE EAST SIDE OF THIS RIDGE...TWO SHRTWVS DIVE SOUTHWARD THROUGH CENTRAL CANADA...WITH A SURFACE LOW DEVELOPING NEAR LAKE WINNIPEG BY 00Z SUN. EXTRAPOLATION OF THESE SHRTWVS AND SURFACE LOW WOULD HAVE THEM MOVING THROUGH WISCONSIN ON SUNDAY...BRINGING SYNOPTIC SNOW TO THE U.P.. THE CANADIAN AND 06Z GFS SHOW A DIFFERENT SCENARIO WITH JUST A BROAD TROUGH SITTING OVER THE GREAT LAKES/ONTARIO/QUEBEC... KEEPING LAKE EFFECT GOING. IN EITHER CASE...CHANCES OF SNOW ARE WARRANTED. GLOBAL MODELS HAVE BACKED OFF SOME ON THE VERY COLD AIR THAT THEY SHOWED YESTERDAY...EXCEPT FOR THE 06Z GFS RUN WHICH STILL DROPS 850MB TEMPS INTO THE LOW -20S C OVER THE CWA ON SUNDAY. THESE READINGS ARE STILL WARMER THAN THOSE SEEN YESTERDAY...SO PREFER THE ECMWF FOR 850MB TEMPS. READINGS THROUGH THE EXTENDED SHOULD BE CLOSE TO NORMAL...BUT IF ANY CLEARING CAN OCCUR DURING THE PERIOD...BELOW ZERO TEMPERATURES ARE LIKELY. && .MQT WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW WARNING UNTIL 6 PM EST MONDAY FOR MIZ006-MIZ007- MIZ085. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY UNTIL 12 PM EST MONDAY FOR MIZ014. GALE WARNING EAST 2/3RDS OF LAKE SUPERIOR. && $$ AJ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 341 PM EST SUN FEB 5 2006 .SHORT TERM...TONIGHT AND MONDAY 12Z RAOBS/WATER VAPOR LOOP SHOW UPPER LOW JUST NORTHEAST OF GEORGIAN BAY...WITH A SHEAR AXIS/JET WRAPPED BACK FROM THE MID ATLANTIC COAST TO THE WESTERN GREAT LAKES. SURFACE ANALYSIS SHOWS THE LOW MOVING INTO NORTHERN QUEBEC...TRYING TO REDEVELOP DOWN ACROSS THE ST LAWRENCE VALLEY/NEW ENGLAND. REGIONAL RADARS SHOW LINGERING WEAK ECHOES ACROSS SOUTHEAST MICHIGAN...WITH STRONGER RETURNS APPARENT ACROSS LAKE HURON ON THE EXETER/WSO RADAR. IR SATELLITE SHOWS SOME ENHANCED/COLDER CLOUD TOPS TRYING TO MOVE DOWN ACROSS THE SAGINAW VALLEY/THUMB. DOWNSLOPE NORTHWESTERLY FLOW IS LEADING TO DRYING AND LIMITED RETURNS ACROSS THE SAGINAW VALLEY...BUT ENOUGH OF AN ONSHORE COMPONENT CONTINUES TO LEAD TO LOWER VISIBILITY RESTRICTIONS AT BAX. DEPARTING STORM SYSTEM WILL CONTINUE TO TRACK NORTHEAST ACROSS QUEBEC TONIGHT AND MONDAY...BUT STRONG CYCLONIC FLOW WILL LINGER ACROSS THE GREAT LAKES. FORECAST SOUNDINGS/TIME SECTIONS SHOW PRETTY LOW INVERSION HEIGHTS...FURTHER DROPPING OVERNIGHT. 18Z RUC INITIALIZATION OF INVERSION AROUND 4-5KFT LOOKS GOOD COMPARED TO 18Z/19Z TAMDAR SOUNDINGS. WITH CURRENT LIGHT ACTIVITY AND INCREASING SUBSIDENCE OVERNIGHT...WILL CARRY LOW POPS THIS EVENING AND DRY OVERNIGHT. DECREASED CLOUD COVER A BIT THROUGH THE NIGHT BUT KEPT ALL AREAS MOSTLY CLOUDY GIVEN MODEST LOW-LEVEL MOISTURE AS WELL AS PASSING MID/UPPER LEVEL MOISTURE ACROSS THE NORTHERN CWA. WEAK SHOT OF LIFT ON MONDAY SEEN BY WEAK 850-500MB QVECTOR CONVERGENCE AHEAD OF THE VORT SHEAR AXIS THAT LIFTS THROUGH. THIS MAY HELP TO LIFT INVERSIONS A BIT. DIURNAL EFFECTS WITH STEEPENING LOW-LEVEL LAPSE RATES WITH LINGERING LOW-LEVEL MOISTURE MAY HAVE MORE OF AN IMPACT...LEADING TO LOW CHANCE POPS. OVERALL PATTERN WITH WEAK CONVERGENCE IN WESTERLY FLOW ACROSS THE SOUTHERN CWA WOULD TEND TO SUPPORT HIGH POPS ACROSS THE SOUTHERN CWA...HOWEVER ONLY KEPT A MENTION OF FLURRIES GIVEN WARMING LOW-LEVEL THERMAL FIELDS AND LIMITED MOISTURE DEPTH. ADJUSTED HIGHS ON MONDAY TO REFLECT SIMILAR READINGS TO TODAY...JUST A TOUCH COLDER OVERALL. DROPPED TEMPS A BIT IN THE NORTHERN CWA UNDER THE CORE OF THE THERMAL TROUGH. BUMPED TEMPS UP A COUPLE DEGREES IN THE FAR SOUTH...WHERE LITTLE OR NO SNOW COVER HAS ALLOWED THEM CLIMB INTO THE MID 30S TODAY. && .LONG TERM...MONDAY NIGHT THROUGH SUNDAY MODELS IN GOOD AGREEMENT DEPICTING DIMINISHING SURFACE CYCLONIC FLOW THROUGH TUESDAY...BEHIND THE RETREATING STORM SYSTEM OF THIS WEEKEND. THEN...MODEL CONSENSUS TRENDS SUPPORTING SURFACE RIDGE BUILDING OVERHEAD AT MID WEEK...GIVING WAY TO AN APPROACHING COLD FRONT LATTER PART OF WEEK WHICH MOST MODELS SHOW PASSING THROUGH THE AREA FRIDAY THEN WITH CYCLONIC FLOW IN ITS WAKE USHERING IN COLDER TEMPERATURES ONCE AGAIN...THOUGH 12Z GFS RUN SLOWS DOWN THE COLD FRONT CONSIDERABLY IN FAVOR OF LOW CENTER SETTLING IN OVER LOWER MI INTO SATURDAY. 00Z ECMWF AND 00Z WRFXX SHOWED A RIDGE NOSING IN BY LATE SATURDAY...BUT THE 12Z WRFXX HOLDS BACK THIS OCCURRENCE UNTIL NEXT SUNDAY...AS OPPOSED TO CONTINUING CYCLONIC WEST TO NORTHWEST FLOW ACROSS AREA THROUGH THE WEEKEND AS PER OTHER MODELS. AT 500 MB...MODELS DEPICT SHORTWAVE TROUGH DROPPING SOUTHEAST OUT OF CANADA TO SOUTH OF THE LAKES REGION AROUND MID WEEK...BUT MUCH MORE ROBUST ENERGY LATER ON IN THE WEEK CARVING OUT A BROAD LOW/TROUGH OVER THE GREAT LAKES REGION BY FRIDAY AND LINGERING NEXT WEEKEND. LOW TO MID LEVEL MOISTURE DIMINISHING MONDAY NIGHT...THEN NOT MUCH THROUGH MID WEEK AT LEAST...BEFORE EXPECTED TO INCREASE TOWARD END OF WEEK. THIS ALSO REFLECTED IN SLIM QPF FIELDS UNTIL AT LEAST THURSDAY. 925 MB MOISTURE...ON THE OTHER HAND...PRETTY GOOD UNTIL LESSENING WITH APPROACH OF SURFACE PRESSURE RIDGE AT MID WEEK. LOW TO MID LEVEL OMEGA LIFT FIELDS SUGGEST GENERAL SUBSIDENCE THROUGH MID WEEK...WITH LITTLE OR NO DYNAMIC LIFT SEEN. BOTTOM LINE...NO INTENSE STORMS APPEAR TO BE ON THE HORIZON FOR THE NEXT WEEK. TEMPERATURES ON THE COLD SIDE...BRIEFLY SHOWING SLIGHT MODERATION AFTER MID WEEK...THEN REINFORCED COLD AIR BY NEXT WEEKEND. AM NOT MAKING CHANGES TO WEATHER...WITH SLIGHT CHANCE OF FLURRIES EARLY WEEK...THEN DRY UNTIL THURSDAY AFTERNOON WITH CHANCE OF SNOW SHOWERS ANY TIME THEREAFTER. && .AVIATION...ISSUED 104 PM EST SUN LINGERING AREA OF HIGHER REFLECTIVITIES APPARENT ON RADAR ACROSS THE CENTRAL CWA...WITH SCATTERED WEAKER REFLECTIVITIES STILL MAKING IT IN FROM NORTHERN AND WESTERN LOWER. CARRIED PREDOMINATE FLURRIES AT MBS/FNT/DTW...WITH MVFR SNOW FOR A COUPLE HOURS AT DET UNTIL THE HIGHER RETURNS CLEAR OUT. KEPT WINDS GUSTY THROUGH THE DAY...AND STRONG SUSTAINED OVERNIGHT AS WE LOSE THE BETTER MIXING BUT MAINTAIN A DECENT GRADIENT. TOUGH CALL AS TO CIGS OVERNIGHT...AS INVERSIONS SLOWLY EDGE DOWNWARD AND STRENGTHEN. HELD ONTO MVFR FOR ALL EXCEPT MBS...WHERE DOWNSLOPING WEST/NORTHWEST FLOW MAY HELP TO ERODE THE LOW CLOUDS FASTER. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... GALE WARNING...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON INCLUDING SAGINAW BAY...UNTIL 6 AM MONDAY. GALE WARNING...OPEN WATERS OF LAKE HURON...UNTIL 6 PM MONDAY. LAKE ST CLAIR...GALE WARNING...UNTIL 6 AM MONDAY. MI WATERS OF LAKE ERIE... GALE WARNING...UNTIL 6 AM MONDAY. LOW WATER ADVISORY...UNTIL 10 AM MONDAY. && $$ SHORT TERM...BRAVENDER LONG TERM....DWD AVIATION...BRAVENDER YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1135 AM EST SUN FEB 5 2006 .UPDATE... MAIN FCST CONCERNS ARE WIND/LES TRENDS. WV IMAGERY AND RUC ANALYSIS INDICATED A DEEP MID/UPR LVL LOW E OF GEORGIAN BAY WITH ANOTHER SHRTWV LOBE OVER NRN ONTARIO. TIGHT GRADIENT BTWN NRN PLAINS RDG AND 981 MB LOW PRES OVER ERN ONTARIO HAS KEPT GALES GOING OVER THE E HLF OF LK SUPERIOR AND GUSTY WINDS TO AROUND 35 MPH OVER N CNTRL UPR MI WITH PLENTY OF BLOWING SNOW. RADAR INDICATED SUBSTANTIAL DIMINISHING TREND SINCE EARLIER THIS MORNING. WITH VERY DRY AIR UPSTREAM(DEWPOINTS TO NEAR -10F) AND BNDRY LYR MIXING BACK EDGE OF LACK CLOUDS HAS PROGRESSED PAST MID LAKE OVER THE WEST. CYQT 12Z TAMDAR SNDG INDICATED 925 TEMP NEAR -15C WITH LOW LVL ISOTHERMAL PRFL AND SIGNIFICANT DRYING ABV 850 MB. BETTER UPSTREAM MOISTURE NOTED NE CYQT TOWARD CYGQ THAT HAS MAINTAINED BETTER LAKE CLOUDS/SNOW OVER THE CNTRL AND ERN PORTION OF THE LAKE. HOWEVER...NO SIGNIFICANT DOMINANT BANDS WITH MOSTLY THIN MULTIPLE WIND PARALLEL BANDS OVER THE NRN LAKE AND MORE CELLULAR APPEARANCE OVER THE SOUTH. EXPECT WINDS WILL NOT DROP OFF MUCH THIS AFTERNOON WITH TIGHT GRADIENT REMAINING IN PLACE AS THE LOW LIFTS SLOWLY NE. LES SHOULD CONTINUE TO DIMINISH OVER THE WEST AS ADDITIONAL MIXING FURTHER DRIES OUT ALREADY UNFAVORABLE LOW LVL MOISTURE PRFL. TO THE EAST...LES SHOULD REMAIN STEADY AND MAY PICK UP LATE AS THE NRN ONTARIO SHRTWV LOBE BRUSHES THE AREA. SO...NO CHANGE IN HEADLINES WERE NEEDED AND UPDATE INCLUDED SOME ADJUSTMENTS TO SNOW ACCUMULATIONS. && .PREV DISCUSSION...ISSUED 535 AM EST SUN FEB 5 2006. UPPER AIR PATTERN CONSISTS OF A 500 MB TROUGH ACROSS THE ERN HALF OF THE U.S. WITH A CLOSED LOW NEAR DETROIT AND A TROUGH ACROSS THE NORTHERN ROCKIES WITH RIDGING IN NEW ENGLAND AND ACROSS ERN CANADA AND RIDGING ACROSS THE SOUTHERN PLAINS. THE TROUGH ACROSS THE ERN HALF OF THE U.S. AND THE CLOSED LOW WILL CONTINUE TO INFLUENCE THE WEATHER FOR THE CWA AS THE CLOSED LOW SLOWLY MOVES NORTH AND KEEPS THE TROUGH FROM MOVING VERY FAR TO THE EAST THROUGH TUE. NAM SHOWS THIS LOW HEADING NORTH TODAY AND WRAPAROUND PART OF THE STORM WILL CONTINUE TO REMAIN ACROSS THE ERN HALF OF THE CWA FOR TODAY. THE MOISTURE OVER THE ERN CWA DOES NOT MOVE OUT UNTIL 00Z TUE WHEN THE 500 MB LOW IS FAR ENOUGH OFF TO THE EAST TO TAKE THE WRAPAROUND PART OF THE STORM OFF TO THE EAST. GFS AND NAM ARE SIMILAR WITH THIS SCENARIO AND WILL USE A MODEL BLEND FOR THIS FORECAST. BOTH MODELS KEEP 850-500 MB Q-VECTOR CONVERGENCE OUT OF THE CWA TODAY JUST TO THE EAST. 850 MB TEMPERATURES CONTINUE TO BE MARGINAL FOR LAKE EFFECT. GFS DOES GO COOLER WITH THEM DURING THE DAY GOING FROM -10C TO -12C AT 12Z DOWN TO -12C TO -16C BY 00Z. NAM IS WARMER AND HAS TEMPERATURES FROM -10C TO -12C AND WITH LAKE SUPERIOR TEMPERATURES AROUND 2C TO 3C...THIS IS MARGINAL FOR LAKE EFFECT UNTIL LATE TODAY...BUT BY THEN THE DEEPER MOISTURE IS GONE. AM A LITTLE LEARY ABOUT THE TEMPERATURES GOING DOWN TO -16C AT 850 WHEN LOOKING AT 00Z 850 MB RAOBS...CWPL IS ONLY -14C AND NO -16C IS VISIBLE IN ANY OF THE RAOB PLOTS. WILL GO WITH WARMER NAM TEMPERATURES WHICH PRODUCE MARGINAL CONDITIONS AS GFS HAS OVERDONE THE COLDER 850 MB TEMPERATURES LATELY. DECIDED TO GO WITH A LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY FOR TODAY FOR MARQUETTE COUNTY BASED ON LAKE ENHANCEMENT AND SOME SEEDER FEEDER GOING ON AS WRAPAROUND MOISTURE IS GOING OVER THE TOP OF SOME LAKE EFFECT SNOW BANDS. WHEN THAT OCCURRED LAST NIGHT...THIS ENDED UP ENHANCING THE SNOWFALL OVER MARQUETTE COUNTY. THINK THIS WILL GO ON THROUGH THE MORNING AS THE WINDS CONTINUE NORTHERLY...AND THEN THIS WILL TAPER OFF IN THE AFTERNOON AS THE WIND GOES MORE NW. THINK 1-4 INCHES LOOK GOOD FOR MARQUETTE COUNTY AND COMBINED THIS WITH BLOWING SNOW...FELT LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY WAS IN ORDER FOR THE LOW VISIBILITIES DUE TO BLOWING SNOW. DECIDED TO DO THE SAME THING FOR ALGER AND ALSO ADDED LUCE AND NORTHERN SCHOOLCRAFT INTO THIS ADVISORY THROUGH TONIGHT WITH COMBINATION OF WIND AND SNOW. LUCE COUNTY WILL HAVE SNOW MORE DUE TO THE WRAPAROUND THEN LAKE EFFECT AS 850 MB TEMPERATURES ARE WARMER THERE. AS YOU GO FURTHER WEST...THE LAKE EFFECT TAKES OVER AS 850 MB TEMPERATURES GET COLDER AND THERE IS LESS SEEDER-FEEDER GOING ON WITH THE WRAPAROUND CONFINED TO THE ERN HALF OF THE CWA. THINK 2-4 INCHES IS LIKELY FOR TODAY AND ANOTHER 1-3 INCHES TONIGHT AND COMBINED WITH THE AREAS OF BLOWING SNOW...THOUGHT LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY WAS APPROPRIATE FOR LUCE AND NORTHERN SCHOOLCRAFT AND ALGER COUNTIES. WENT WITH 1-4 INCHES TODAY ACROSS THE WEST ALSO AS CALLS OUT TO IRONWOOD REVEALED 2-4 INCHES OF SNOW OVERNIGHT AND THIS DID SEEM HIGH CONSIDERING THAT THE AIRMASS IS DRIER OVER THERE...BUT WAS CONFIRMED BY MORE THAN ONE SOURCE. EVEN WITH THE DRY AIR UPSTREAM...MUST BE GETTING GREATER THAN A 20 TO 1 RATIO TO GET THAT TYPE OF SNOW AMOUNT...AND THINK THIS WILL CONTINUE FOR TODAY. INVERSION HEIGHTS ARE PRETTY LOW WITH CWPL 00Z SOUNDING AROUND 925 MB AND KINL NOT MUCH LOWER THAN THAT...SO THINK THINGS WILL NOT GET TOO OUT OF HAND IN THE WEST. THE LAKE EFFECT EVENT LOOKS TO CONTINUE THROUGH TUE AT LEAST WITH COLD 850 MB TEMPERATURES AND NW WINDS CONTINUING...BUT DEEP MOISTURE IS GONE AFTER TONIGHT...SO PURE LAKE EFFECT WILL START UP TONIGHT. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR TEMPERATURES OR WEATHER. && .MQT WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY UNTIL 6 PM EST MIZ005. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY UNTIL 6 AM EST MON MIZ006-007-085. GALE WARNING EAST 2/3RDS OF LAKE SUPERIOR. && $$ JLB(UPDATE) MICHELS(PREV DISC) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 250 PM CST SUN FEB 5 2006 .SHORT TERM...THIS AFTERNOON THROUGH 12Z WEDNESDAY. PRIMARY FORECAST CONCERN IS THE CHANCE FOR FLURRIES OR LIGHT SNOW THIS EVENING AND TONIGHT. SFC OBSERVATIONS SHOW A TROUGH OF LOW PRESSURE EXTENDING FROM NORTH TO SOUTH ACROSS WESTERN PORTIONS OF NEBRASKA AND KANSAS. EAST WINDS AHEAD OF THIS TROUGH...AND ESPECIALLY ACROSS OUR CWA...CONTINUE TO ADVECT COOL DRY AIR INTO SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS. RUC MODEL ANALYSIS SHOWS A WEAK 500 MB SHORT WAVE TRACKING ACROSS COLORADO PROVIDING THE DYNAMICS FOR A LITTLE LIGHT SNOW. HOWEVER...THE LACK OF LOW LEVEL MOISTURE WILL SIGNIFICANTLY INHIBIT POSSIBLE ACCUMULATIONS. ELEVATED RADAR RETURNS CONTINUE TO SHOW SNOW ALOFT ESPECIALLY JUST NORTH AND WEST OF OUR CWA...BUT DRY AIR NEAR THE SFC IS EVAPORATING NEARLY ALL OF THIS PRECIPITATION BEFORE IT CAN REACH THE GROUND. THE LOWER ATMOSPHERIC LAYERS WILL GRADUALLY MOISTEN UP THIS EVENING ACROSS FAR WESTERN ZONES...PRIMARILY WEST OF HWY 183. THIS COULD ALLOW FOR ANYWHERE FROM A DUSTING UP TO A HALF INCH OF SNOW IN THESE FAR WESTERN ZONES BY TOMORROW MORNING. CENTRAL AND EASTERN ZONES REALLY NEVER FULLY MOISTEN UP...WHICH THANKS TO EXTENSIVE EVAPORATION OF SNOW ALOFT...THE 281 CORRIDOR SHOULD ONLY SEE A DUSTING OR SO OF SNOW ACCUMULATION. FAR EASTERN ZONES WILL BE EVEN DRIER AND MAY ONLY SEE A FEW FLURRIES WHICH WOULD HOLD OFF UNTIL AFTER SUNSET. A GOOD NORTHERLY FETCH OF AIR ALOFT WILL CONTINUE TO USHER IS COOL AIR ON MONDAY AND TUESDAY KEEPING TEMPERATURES NEAR NORMAL. IN ADDITION...A CANADIAN CLIPPER WILL SLIDE DOWN THE BACK SIDE OF THE WEST COAST RIDGE BRINGING ANOTHER CHANCE OF A FEW FLURRIES TO OUR EASTERN ZONES ON TUESDAY. .LONG TERM...12Z WEDNESDAY THROUGH SUNDAY. MAIN FORECAST CHALLENGE INVOLVES TEMPERATURES AS THE REGION UNDERGOES A PATTERN CHANGE IN THE EXTENDED PERIODS. ON WEDNESDAY...THE UPPER PATTERN SHIFTS LITTLE OVER THE CENTRAL PLAINS AS A NORTH-NORTHWESTERLY FLOW CONTINUES ALOFT IN RESPONSE TO A BROAD RIDGE OVER THE WESTERN STATES AND A BROAD TROUGH OVER THE EASTERN STATES. ON THURSDAY THE UPPER FLOW BECOMES NORTHWESTERLY AS A SHORTWAVE TROUGH DIVES SOUTHEASTWARD OUT OF SOUTH CENTRAL CANADA INTO THE EXTREME NORTH CENTRAL PORTION OF THE U.S. LOW LEVEL WARM AIR ADVECTION ON THURSDAY WILL BRING THE PEAK IN DAYTIME HIGH TEMPERATURES TO THE CENTRAL PLAINS. ON FRIDAY...THE SHORTWAVE TROUGH DIVING SOUTHEASTWARD INTO THE U.S. WILL PUSH A FRONT INTO THE LOCAL AREA THAT WILL BRING NOTICIBLY LOWER DAYTIME HIGH TEMPERATURES THAN THOSE SEEN ON THURSDAY. FOR THE FIRST TIME IN SEVERAL WEEKS...TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW NORMALS FOR THIS TIME OF THE YEAR. THIS COOLING TREND WILL CONTINUE INTO SATURDAY AS THE TROUGH OF LOW PRESSURE OVER SOUTHEASTERN CANADA AND THE GREAT LAKES CONTINUES TO STRENGTHEN AND EXPAND OUTWARD FROM ITS CENTER. ON SUNDAY...THE TROUGH WILL CONTINUE TO EXPAND WESTWARD AND THIS WILL ALLOW COLDER AIR TO CONTINUE TO FILTER INTO THE REGION WITH TEMPERATURES REMAINING NEAR NORMAL. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ WESELY\JAR ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1112 AM CST SUN FEB 5 2006 .UPDATE...LOW PRESSURE AT THE SURFACE THIS MORNING...FROM WESTERN OKLAHOMA INTO THE HIGH PLAINS...WAS HAVING DIFFICULTY CONSOLIDATING INTO ONE WELL DEFINED CENTER. PRESSURE FALLS CONTINUE FARTHER SOUTH AND EAST TOWARD THE INTERSTATE 44 CORRIDOR...WHICH SHOULD KEEP THE ELONGATED SURFACE LOW MOVING THAT DIRECTION THIS AFTERNOON. AHEAD OF THE LOW...A WARM FRONT WAS LIFTING VERY SLOWLY THROUGH NORTH CENTRAL OKLAHOMA...AND BEHIND THE LOW...A COLD FRONT WAS AIMING TO CATCH UP AS IT MOVED OUT OF THE OKLAHOMA AND TEXAS PANHANDLES. ALL THIS EVIDENCE COMBINED WITH LATEST RUNS OF THE RUC AND GFS MODELS...SUPPORT THE GOING WIND FORECAST...WHICH FEATURES GUSTY SOUTH WINDS GIVING WAY TO LIGHTER WEST WINDS...THEN GUSTY NORTH WINDS...AS THE SURFACE LOW PROGRESSES QUICKLY ACROSS THE FORECAST AREA. MAIN UPDATE WAS TO RAISE TEMPERATURES A FEW DEGREES BASED ON CLEARING SKIES AND A TEMPORARY DOWNSLOPE WIND THAT WILL DEVELOP IN MOST AREAS DURING PEAK HEATING. THE ONLY EXCEPTION WILL BE NORTH OF THE WARM FRONT IN FAR NORTH CENTRAL OKLAHOMA. GIVEN THE SLIGHT INCREASE IN TEMPERATURES...POCKETS OF EXTREME FIRE DANGER MAY DEVELOP BRIEFLY IN FAR WESTERN NORTH TEXAS AND IN OKLAHOMA ALONG THE BORDER WITH THE TEXAS PANHANDLE. THE EVENT STILL LOOKS BEST HANDLED WITH THE FIRE DANGER STATEMENT WHICH IS ALREADY IN PLACE. ALSO LOOKED INTO WIND SPEEDS BEHIND THE FRONT...AND DO NOT ANTICIPATE ANYTHING TOO EXTREME AT THIS TIME. DEEP MIXING AND COLD ADVECTION/SUBSIDENCE SHOULD PROVIDE A WINDY AFTERNOON AND EVENING...BUT THE FORECAST MEAN LOW LEVEL WIND SPEEDS DO NOT SUPPORT ADVISORY CRITERIA. BURKE. && .PREV DISCUSSION... (ISSUED 351 AM CST SUN FEB 5 2006) DISCUSSION... FIRE WX IS OF SOME CONCERN TODAY WITH SOME AREAS LIKELY REACHING VERY HIGH CATEGORY. HOWEVER... APPEARS THAT TIMING OF THE CORRECT PARAMETERS WILL BE OFF ENOUGH THAT WILL NOT ISSUE A RED FLAG WARNING AND COVER WITH THE RFD/HWO/ETC. A SFC LOW IS EXPECTED TO MOVE INTO WEST CENTRAL OK/TX PANHANDLE BY AROUND MID DAY CAUSING PRESSURE GRADIENT TO RELAX WITH THE STRONGEST WINDS IN SE PORTIONS OF FA WHERE DEWPTS WILL BE GRADUALLY INCREASING. SW PORTIONS OF FA WILL LIKELY HAVE RH LESS THAN 20 PERCENT BUT BELIEVE WHEN LIGHTER WINDS OVR THE AREA. THE SFC LOW WILL CONT TO MOVE INTO TX THIS AFTN CAUSING A COLD FRONT TO MOVE QUICKLY ACROSS THE AREA. THERE COULD ALSO BE A SMALL WINDOW OF INCREASED FIRE WX CONDITIONS BEHIND THE COLD FRONT AS TEEN DEWPTS MOVE INTO THE FA ALONG WITH THE STRONG NW WINDS. THE MOST LIKELY AREA WHERE THIS COMBINATION COULD OCCUR WOULD BE WEST CENTRAL/SW OK. HOWEVER... WOULD LIKELY BE MID TO LATE AFTN WHEN TEMPS WILL BE STEADY OR BEGINNING TO FALL SO RH VALUES MAY NOT HAVE AN OPPORTUNITY TO FALL BELOW 20 PERCENT. WILL DESCRIBE THESE THINGS IN PRODUCTS MENTIONED ABOVE AND LET DAY SHIFT CONT TO MONITOR FOR ANY POSSIBILITIES OF NEEDING TO ISSUE A WARNING. THERE MAY BE ENOUGH LIFT TONITE AS A SHORTWAVE MOVES ACROSS THE SOUTHER PLAINS FOR SOME LIGHT PRECIP IN NE PORTIONS OF FA... SO HAVE ADDED SLIGHT CHANCE POPS. IF DOES HAPPEN... WILL LIKELY BEGIN AS SPRINKLES/LIGHT RA AND MAY SWITCH OVR TO FZ DZ/SNOW FLURRIES JUST BEFORE ENDING. THE FREEZING PRECIP IS EXPECTED TO BE LIGHT ENOUGH TO HAVE LITTLE IMPACT ON THE AREA. MODELS SHOWING ANOTHER SHORTWAVE MOVING ACROSS THE PLAINS JUST AHEAD OF AN UPR LOW THAT ROTATES FROM THE UPR MIDWEST INTO THE OHIO VALLEY AROUND MID WEEK. THIS WILL BRING ANOTHER COLD FRONT ON TUES WITH COLDER AIR MOVING INTO THE AREA. MODELS ALSO SHOWING A SHOT OF EVEN COLDER CANADIAN AIR MOVING INTO THE ARE LATE THIS WEEK/NEXT WEEKEND. HOWEVER... STILL DO NOT EXPECT ANY PRECIP WITH THESE SYSTEMS. HAVE NOT MADE ANY MAJOR CHANGES TO EXTENDED. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 62 30 51 27 / 0 10 0 0 HOBART OK 66 28 55 26 / 0 0 0 0 WICHITA FALLS TX 69 32 58 29 / 0 0 0 0 GAGE OK 57 22 53 22 / 0 0 0 0 PONCA CITY OK 50 25 48 23 / 10 20 0 0 DURANT OK 65 36 53 29 / 0 10 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 20/25 ok AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 1034 AM MST SUN FEB 5 2006 .DISCUSSION...WATER VAPOR IMAGERY SHOWS A COUPLE OF SHORTWAVES ACROSS THE NORTHERN PLAINS...ONE ENTERING THE NEBRASKA PANHANDLE...AND THE OTHER DROPPING THROUGH CENTRAL MONTANA. AT THE SURFACE...TROUGH BETWEEN TWO LOW PRESSURE CENTERS IS CURRENTLY OVER THE AREA WITH WINDS PREDOMINATELY OUT OF THE NORTHWEST. TEMPERATURES RANGE FROM THE 20S ACROSS THE SOUTH DAKOTA PLAINS...TO THE LOW 30S ACROSS THE BLACK HILLS AND NORTHEASTERN WYOMING. A BROAD AREA OF ASCENT HAS DEVELOPED OVER MOST OF THE FORECAST AREA...WITH RADAR REFLECTIVITY ON THE INCREASE ACROSS WESTERN SOUTH DAKOTA. CURRENT RUC HAS A GOOD HANDLE ON THE PRECIP FIELDS THIS MORNING...AND HAVE BASED AFTERNOONS FORECAST ON ITS OUTPUT. SNOW SHOULD CONTINUE TO DEVELOP OVER THE PLAINS OF WESTERN SOUTH DAKOTA WITH SOME UPSLOPE ENHANCEMENT OVER THE BEAR LODGE MOUNTAINS AND THE NORTHERN BLACK HILLS. SNOWFALL TOTALS SHOULD ONLY BE AROUND AN INCH ACROSS THE PLAINS...WITH UP TO 4 INCHES IN THE MORE FAVORED AREAS OF THE BLACK HILLS. WITH PRECIP FALLING FOR THE REMAINDER OF THE DAY ACROSS THE AREA...HAVE DROPPED HIGH TEMPERATURES DOWN SEVERAL DEGREES. SECOND SHORTWAVE DROPPING OUT OF MONTANA WILL SLIDE ACROSS NORTHEASTERN WYOMING THIS EVENING...SO WILL MOST LIKELY BE UPPING POPS ACROSS THAT AREA IN THIS AFTERNOONS FORECAST PACKAGE. FORECAST UPDATES ARE OUT. && .AVIATION...IFR/MVFR CONDITIONS DUE TO LOWER CLOUDS AND SNOW WILL AFFECT MUCH OF THE FORECAST AREA THROUGH THIS AFTERNOON. IMPROVEMENT WILL BEGIN THIS EVENING...WITH LINGERING PRECIPITATION AROUND. && .UNR...WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ sd