WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL 825 PM EST FRI MAR 12 2004 .DISCUSSION...A SUB TROPICAL JET CONTINUES TO STREAM EAST ACROSS THE GULF AND PROVIDE SOME HIGH CIRRUS OVER THE CWA. LATEST RUC SHOWS ONE UPPER LOW EXITING NORTHERN NEW ENGLAND WITH A SECOND LOW MOVING ACROSS THE DESERT SOUTHWEST WITH NEARLY ZONAL FLOW ALOFT OVER THE GULF AND FL. SURFACE ANALYSIS HAS A SURFACE HIGH OVER THE MID WEST RIDGING SOUTH TO THE GULF WITH A WEAK FRONT/SFC TROUGH OVER THE SOUTHEAST U.S. COAST. THIS HIGH WILL SLOWLY EASE TO THE EAST...KEEPING LIGHT N & NE FLOW ACROSS THE CWA TONIGHT. FORECAST LOWS TONIGHT THAT RANGE FROM MID 45 NORTH TO MID 50S SOUTH LOOK ON TRACK. DESPITE THE FAIRLY DRY DAY THERE SHOULD BE ENOUGH MOISTURE RECOVERY OVER NIGHT FOR SOME FOG. BUT THIS SHOULD ONLY BE PATCHY IN NATURE...THERE WILL SOME WIND ALTHOUGH LIGHT AND HIGH CLOUDS WILL BE STREAKING BY. CURRENT PUBLIC ZONES LOOK GOOD AND WILL NOT UPDATE. LIKEWISE THE COASTAL WATERS FORECAST IS IN GOOD SHAPE AND WILL ISSUE AROUND 1020 WITH OUT CHANGE. && .FIRE WEATHER...THE AIRMASS CONTINUES TO SLOWLY MOISTEN. HOWEVER ENOUGH DRY AIR WILL LINGER...MAINLY ACROSS THE NORTH...FOR ONE MORE DAY WITH A FIRE WEATHER WATCH ACROSS INLAND LEVY COUNTY. && .TBW WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FOR INTERIOR SECTIONS OF LEVY SATURDAY AFTERNOON. && $$ RKR fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 930 AM EST FRI MAR 12 2004 .SHORT TERM...RUC FORECASTS ARE HINTING AT SEABREEZE ACTIVITY THIS AFTERNOON...WHICH SEEMS REASONABLE GIVEN OUR VERY LOOSE LOCAL PRESSURE GRADIENT AND AN EXPECTED 10 DEGREE (F) LAND/WATER TEMPERATURE GRADIENT. WILL ADJUST WINDS ACCORDINGLY IN THE COASTAL WATERS FORECAST. DO NOT EXPECT A VERY DEEP INLAND PENETRATION OF THE SEABREEZE...SO OUR CURRENT RED FLAG WARNING LOOKS ON TRACK. NO OTHER CHANGES ARE PLANNED. && .PREVIOUS DISCUSSION... 240 AM EST FRI MAR 12 2004 .CURRENTLY...A DRY COLD FRONT WAS ADVANCING SOUTHEASTWARD FROM WESTERN NORTH CAROLINA SOUTHWEST INTO NORTHERN LOUISIANA AT 03Z. CLOSER TO HOME WINDS WERE LIGHT OR CALM AND SKIES WERE CLEAR. && .SHORT TERM (TODAY THROUGH SUNDAY)... THE COLD FRONT WILL CROSS MY CWA FROM NW TO SE LATE THIS MORNING THROUGH THIS EVENING BRINGING A REENFORCEMENT OF DRY AIR TO THE LOCAL REGION. NOT EXPECTING COLD TEMPERATURES WITH THIS FRONT SINCE THE CENTER OF THE HIGH IN ITS WAKE STAYS WELL TO OUR NORTH AS IT SLIDES EAST ACROSS THE TENNESSEE VALLEY TO THE MID ATLANTIC REGION TONIGHT THROUGH SATURDAY. ADDITIONALLY...FLOW ALOFT DURING THIS TIME WILL BE NEARLY ZONAL. AS THE RESULT...THE FRONT STALLS OVER NORTH CENTRAL FLORIDA SATURDAY. WITH THE HIGH MOVING EAST...OUR LOW LEVEL FLOW WILL VEER FROM THE NORTHWEST TODAY TO THE EAST SATURDAY. ON SUNDAY...UPPER FLOW BACKS WITH A SHORT WAVE APPROACHING THE SOUTHEASTERN STATES. MEANWHILE...THE SURFACE HIGH SLIDES INTO THE WESTERN ATLANTIC WITH THE STATIONARY FRONT LIFTING TO THE NORTH AS A WARM FRONT. THE ASSOCIATED COLD FRONT ENTERS THE SOUTHEAST SUNDAY WITH DECENT RETURN FLOW INCREASING MOISTURE INTO THIS SYSTEM. HOWEVER...THE PROSPECTS FOR RAIN THROUGH 00Z MONDAY ARE SLIGHT SO WILL KEEP THE INHERITED 20% POP OVER OUR WESTERN ZONES SUNDAY AFTERNOON WITH A SILENT 10% POP EASTERN ZONES. GRADUAL WARMING TREND THROUGH THE PERIOD WITH MIN TEMPS WARMING INTO THE LOWER 50S AND MAX TEMPS RISING INTO THE UPPER 70S BY SUNDAY. && .MARINE...WINDS WILL REMAIN BELOW HEADLINE CRITERIA AS THEY VEER FROM NORTH TO EAST THROUGH SATURDAY AND THEN TO THE SOUTHEAST ON SUNDAY. WINDS MAY BRIEFLY REACH SCEC LEVELS IN THE WAKE OF THE NEXT COLD FRONT MONDAY NIGHT INTO EARLY TUESDAY. && .FIRE WEATHER...THE REENFORCEMENT OF DRY AIR WILL RESULT IN LONG DURATIONS OF MINIMUM RELATIVE HUMIDITY BELOW 35% TODAY OVER ALL BUT THE IMMEDIATE COAST OF OUR FLORIDA ZONES. THUS A RED FLAG WARNING IS IN EFFECT. A WATCH WILL BE POSTED FOR SATURDAY AFTERNOON FOR THE SAME AREAS DUE TO POSSIBLE LONG DURATIONS OF LOW RELATIVE HUMIDITY. && .PRELIMINARY POINT TEMPS/POPS... TLH 74 40 72 47/ 00 00 00 00 PFN 71 47 71 53/ 00 00 00 00 DHN 70 42 69 49/ 00 00 00 00 ABY 71 40 69 47/ 00 00 00 00 VLD 74 42 71 48/ 00 00 00 00 CTY 74 43 75 49/ 00 00 00 00 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...RED FLAG WARNING EXCEPT IMMEDIATE COAST THIS AFTERNOON. FIRE WX WATCH EXCEPT IMMEDIATE COAST SATURDAY AFTERNOON. && $$ TJT/BARRY fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 730 PM MST FRI MAR 12 2004 .UPDATE... HAVE MADE A FEW UPDATES FOR THE FIRST THREE PERIODS..MAINLY FOR TIMING ISSUES ON THE EXPECTED WINDS TONIGHT THROUGH SATURDAY NIGHT. TONIGHT...SOUTH AND GUSTY WINDS CONTINUE OVER MUCH OF THE AREA AND WILL DO SO THROUGH 09Z OR SO WHEN THE PRE-FRONTAL TROUGH BEGINS TO ENTER THE NORTHWEST PORTION OF THE FORECAST AREA. MIN TEMPERATURES LOOK PRETTY GOOD GIVEN LAST 5 DAY BIAS OF THE VARIOUS 2M/MOS GUIDANCE PRODUCTS. ADJUSTED THE SKY COVER GRIDS A BIT TO BRING IN CLOUDINESS A BIT LATER THAN PREVIOUS FORECAST. AS NOTED BY KGRI...FOG MAY NOT COME INTO PLAY AFTER MIDNIGHT. ETA BOUNDARY LAYER RH ISNT ALL THAT IMPRESSIVE AND ALTHOUGH I WOULD EXPECT SOME LOW CLOUDS THE PROSPECTS OF FOG DONT IMPRESS ME. GIVEN SOME UNCERTAINTY WILL LEAVE IT IN. SATURDAY/SATURDAY NIGHT..USED THE ETA MOS ADJUSTED GUIDANCE IN THE GRIDS. ETA AND 00Z FSL RUC II ARE IN CONCERT WITH EACHOTHER WITH THE FRONTAL TIMING AND WINDS BEHIND IT. BROKE THE GRIDS DOWN TO 3 HOURLY FORECASTS VS 6 HOURLY TO HOPEFULLY GIVE A BIT MORE DETAIL. THATS ABOUT IT AT THIS POINT. WILL CONTINUE TO MONITOR HOURLY TEMP/DEWPOINT GRIDS THROUGH THE REMAINDER OF THE EVENING AND TWEAK AS APPROPRIATELY NEEDED. WILL ADVISE INCOMING SHIFT TO THE CHANCE THAT A FEW THUNDERSTORMS ARE POSSIBLE OVER THE EXTREME EAST/SOUTHEAST CORNER OF OUR FORECAST AREA LATE SATURDAY AFTERNOON PER LATEST ETA INSTABILITY PARAMETERS AND SPC DAY 2 OUTLOOK. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ DDT ks AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE PADUCAH KY 525 AM CST FRI MAR 12 2004 .DISCUSSION... THE MAIN ISSUE FOR THIS FORECAST PACKAGE IS THE CHANCE FOR PRECIPITATION OVER THE WEEKEND. IN THE MEANTIME...HIGH PRESSURE IS FORECAST TO SLIDE FROM THE NORTHERN PLAINS INTO THE OHIO VALLEY BY EARLY SATURDAY. FOR THE FOUR-STATE REGION...THIS EQUATES TO LOTS OF SUNSHINE TO ROUND OUT THE WORK WEEK. WHILE WINDS WILL PICK UP OUT OF THE NORTHWEST AROUND 10 MPH...THE ABUNDANT SUNSHINE SHOULD HAVE NO PROBLEM WARMING TEMPERATURES SOME 20 TO 25 DEGREES FROM MORNING LEVELS. ACCORDINGLY...UTILIZED THE WARMER TEMPERATURES FROM THE FWC/MESOETA/RUC FOR TODAY/S HIGHS. TONIGHT...HIGH CLOUDS WILL BE ON THE INCREASE FROM THE WEST...BUT WINDS SHOULD REMAIN VERY LIGHT. THESE TWO FACTORS WILL HAVE OPPOSITE EFFECTS ON TEMPERATURES...SO HEDGED WARMER THAN MOS VALUES BUT NOT QUITE AS WARM AS MESOETA 2M TEMPS. OVER THE WEEKEND...AN UPPER-LEVEL TROUGH WILL PUSH EAST FROM THE NORTHERN PLAINS INTO THE MIDWEST. WITH THE REGION AT THE BASE OF THE TROUGH...INCREASING MOISTURE AND LIFT WILL RESULT IN A CHANCE FOR SHOWERS FROM LATE SATURDAY INTO SUNDAY. MOST OF THE RAIN SHOULD HOLD OFF UNTIL SATURDAY NIGHT...EXCEPT ALONG AND WEST OF THE MISSISSIPPI RIVER. FOR BOTH SATURDAY AND SATURDAY NIGHT...THE REDUCED DIURNAL TEMPERATURE RANGE OF THE MAV GUIDANCE SEEMS MORE REASONABLE GIVEN THE AMOUNT OF SKY COVER AND CHANCE FOR PRECIPITATION. AFTER THE PEAK CHANCE OF PRECIPITATION SUNDAY...THE UPPER TROUGH WILL MOVE THROUGH. THIS MAY YIELD A FEW SPRINKLES SUNDAY NIGHT. OVERALL...EXPECT THE PRECIP TO BE OVER BY EARLY MONDAY. WILL MAINTAIN DRY WEATHER TUESDAY AND WEDNESDAY...WITH A CHANCE OF RAIN ON THURSDAY AS WAS INTRODUCED ON THE PREVIOUS SHIFT. GENERALLY MADE NO CHANGES TO THIS FORECAST PACKAGE BEYOND SUNDAY NIGHT. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. KY...NONE. MO...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1130 AM EST FRI MAR 12 2004 .SHORT TERM...THIS MORNING/S SURFACE PLOT DEPICTS LOW PRESSURE CENTERED OVER QUEBEC WITH ARCTIC FRONT STRETCHING BACK INTO THE OHIO VALLEY. 12Z RAOBS FROM KAPX/KGRB SHOW ABUNDANT MOISTURE BELOW 850MB AND SUBSIDENCE ABOVE INCREASING ACROSS THE GREAT LAKES REGION. 12Z UPPER AIR MAPS AND INFRARED SATELLITE INDICATE A WEAK 700MB TROUGH OVER LAKE SUPERIOR THIS MORNING AHEAD OF BUILDING RIDGE OVER THE NORTHERN PLAINS. MAIN CONCERN THIS AFTERNOON WILL BE TIMING OUT OF LAKE EFFECT SNOW SHOWERS. ETA/RUC MODELS INITIALIZED TOO WARM THIS MORNING ACROSS MICHIGAN. 850MB TEMPERATURES FROM KAPX/KGRB RAOBS OF -19C WITH LAKE TEMPERATURES AROUND 0-1C PRODUCE LAKE-850MB DELTA T/S AROUND 20C...MORE THAN SUFFICIENT TO PRODUCE LAKE EFFECT SNOW SHOWERS. 900-700MB RH/S SHOULD DECREASE TO AROUND 40 PERCENT BY LATE THIS AFTERNOON. LATEST 88D RADAR TRENDS FROM KMQT AND KAPX SHOW NUMEROUS SNOW SHOWERS STILL OCCURRING ACROSS MUCH OF THE FORECAST AREA...THOUGH IT SHOULD SCATTER OUT IN THE AFTERNOON WITH DEEPENING SUBSIDENCE AND DECREASING RH. I ALSO ADJUSTED HIGH TEMPERATURES DOWN THIS AFTERNOON BASED ON CURRENT TRENDS. CJC PREVIOUS DISCUSSION...ISSUED 4AM EST MON MAR 12 2004 .LONG TERM...A TEMPORARY BREAK IN THE ACTION TONIGHT AND SATURDAY WILL GIVE NRN MICHIGAN A CHANCE TO RECOVER FROM THE WIND AND SNOW... BEFORE THE NEXT SHOT OF SYNOPTIC SNOW BEGINS TO IMPACT THE REGION SATURDAY NIGHT. MODELS STILL PROJECT DIFFERING SOLUTION WITH RESPECT TO THIS NEXT SYSTEM. ETA IS SIGNIFICANTLY MORE PROGRESSIVE...DRIVING THE LOW ALONG THE US/CANADIAN BORDER TO A POSITION NE OF LAKE SUPERIOR BY 18Z SUNDAY. THE GFS DEPICTS A SIMILAR TRACK...BUT DOES NOT PUSH THE LOW EAST OF LAKE SUPERIOR UNTIL SUNDAY EVENING. THIS DIFFERENCE IN TIMING WILL HAVE A BIG IMPACT ON HOW LONG MICHIGAN REMAINS IN THE DEEP MOISTURE AND WHEN THE DRY SLOW ARRIVES. AT THIS POINT...THINK THE ETA MAY HAVE THE RIGHT IDEA GIVEN THE RATHER PROGRESSIVE LONG WAVE PATTERN AS OF LATE. IN LEANING TOWARD THE ETA...THE MAIN EVENT WILL HAPPEN SATURDAY NIGHT...ESPECIALLY OVERNIGHT. TONIGHT AND SATURDAY...HIGH PRESSURE/SURFACE RIDGING REMAINS IN PLACE THRU MOST OF THE PERIOD. MAINLY CLEAR SKIES...RELATIVELY LIGHT WINDS AND A FRESH SNOW PACK WILL ALLOW OVERNIGHT LOW TONIGHT TO DROP WELL INTO THE SINGLE DIGITS ABOVE ZERO. LOW/MID LEVEL WAA BEGINS SATURDAY (MAINLY IN THE AFTERNOON)...BUT MID/UPPER LEVEL CLOUDS WILL BE ON THE INCREASE. HIGH TEMPS SHOULD RISE BACK INTO THE LOWER TO MID 30S WITH STRENGTHENING WAA...BUT INCREASING CLOUDS SHOULD LIMIT SURFACE HIGH TEMPS. SATURDAY NIGHT AND SUNDAY...STILL A GREAT DEAL OF UNCERTAINTY WITH RESPECT TO THE UPCOMING STORM. IF ETA IS RIGHT (WHICH IS THE PREFERRED SOLUTION)...INITIAL SHOT OF ISENTROPICALLY DRIVEN SNOW (I290) WILL REACH WRN SECTIONS OF THE CWA SATURDAY EVENING AND OVERSPREAD THE ENTIRE CWA OVERNIGHT. DRY SLOW THEN REACHES THE CWA SUNDAY MORNING BEFORE WRAP AROUND MOISTURE AND LOW LEVEL CAA WRAP BACK INTO MICHIGAN SUNDAY NIGHT. AIRMASS BEHIND THIS LOW IS SUFFICIENTLY COLD FOR LAKE EFFECT SNOW SHOWERS TO REDEVELOP SUNDAY AFTERNOON AND CONTINUE INTO SUNDAY NIGHT (AT LEAST)...ESPECIALLY FOR LOCATIONS TARGETED BY W AND NW FLOW. AT THIS POINT...WILL TRY TO BE MORE SPECIFIC IN TIMING THE SNOW INTO THE REGION SATURDAY NIGHT... BUT KEEP THE HIGHEST POPS FOR THE OVERNIGHT HOURS WHEN ISENTROPIC ASCENT IS MAXIMIZED. WILL KEEP SCATTERED SNOW SHOWERS IN THE FORECAST FOR SUNDAY AND SUNDAY NIGHT BEHIND THE SYSTEM. NO CHANGES MADE TO THE REST OF THE FORECAST. EME && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1109 AM EST FRI MAR 12 2004 .UPDATE... CLOUD COVER ON SATELLITE IMAGERY LOOKS PRETTY SOLID LATE THIS MORNING. GIVEN STRONG 850 MB TROUGH OVERHEAD MOST OF THE AFTERNOON TO PROMOTE STEEP LOW LEVEL LAPSE RATES...AND QUITE A BIT OF LOW LEVEL MOISTURE AS PER NEW MODEL RUNS...WILL GO MOSTLY CLOUDY FOR THE AFTERNOON. ALSO...WILL CONTINUE MENTION OF SCATTERED SNOW SHOWERS SOUTH AND SCATTERED FLURRIES NORTH THIS AFTERNOON. LATEST MODEL SOUNDINGS INDICATE CONTINUED SOMEWHAT ELEVATED INVERSION HEIGHT THIS AFTERNOON AHEAD OF VORTICITY PERTURBATION DIVING SOUTHEAST FROM UPPER MISSISSIPPI VALLEY WITH WEAK TO MODEST 850 TO 500 MB DIFFERENTIAL PVA/QVECTOR CONVERGENCE AND A BIT OF LOW LEVEL CONVERGENCE...AND EVEN SOME 850 TO 700 MB FRONTOGENETICAL FORCING MAINLY IN THE SOUTH. UPDATED ZONES TO BE ISSUED SHORTLY. && DWD .PREV DISCUSSION...ISSUED 400 AM EST. 00Z RAOBS/WATER VAPOR LOOP SHOW POTENT SHORTWAVE JUST SWINGING THROUGH THE STATE...LEADING TO AMPLIFIED PATTERN WITH NORTHWEST FLOW INTO THE GREAT LAKES. UPSTREAM RIDGE OVER THE NORTHERN ROCKIES AND LOW OVER NORTHWEST MEXICO...WITH NEXT SHORTWAVE MOVING ONSHORE OF BRITISH COLUMBIA. SURFACE ANALYSIS SHOWS LOW INTO QUEBEC BUT WITH TIGHT GRADIENT REMAINING BACK ACROSS THE STATE WITH DECENT SURFACE TROUGH. SURFACE RIDGE EXTENDS FROM WESTERN ONTARIO TO THE SOUTHERN PLAINS. REGIONAL RADARS SHOW A DECENT AMOUNT OF ECHOES...BUT BEGINNING TO DIMINISH WITH A TRANSITION FROM SYNOPTIC TO LAKE EFFECT. INITIAL FORECAST CONCERNS REVOLVE AROUND SNOW TO START THE DAY...FOLLOWING BY A FEW CHANGES TO THE FORECAST REGARDING THE NEXT SYSTEM FOR THE LAKE WEEKEND/EARLY NEXT WEEK. WAVE VAPOR/06Z RUC SHOWS THE UPPER WAVE THAT ENHANCED SNOWFALL OVERNIGHT HAS MOVE EAST...AND REGIONAL RADARS SHOW PRECIP BEGINNING TO DIMINISH IN THE SUBSIDENCE FOLLOWING IT. HOWEVER COLD AIR CONTINUES TO POUR OVER THE LAKES /-15C OBSERVED AT GRB 00Z/ WHICH IS FORECAST TO SPREAD ACROSS THE STATE BY AFTERNOON. HOWEVER INVERSION HEIGHTS ALSO QUICKLY DROP TODAY WITH GOOD SUBSIDENCE FOLLOWING THE SHORTWAVE. WITH DRY AIR AND INVERSIONS DROPPING TO 3KFT ON FORECAST SOUNDINGS...IN ADDITION TO LOW-LEVEL FLOW BECOMING MORE NEUTRAL...EXPECT SNOW SHOWERS TO CONTINUE TO DIMINISH THROUGH THE MORNING. APPEAR THERE WILL BE ENOUGH DRYING TO KEEP PARTLY SUNNY GOING FOR THE AFTERNOON. WILL END FLURRIES THIS MORNING DUE TO THE AMOUNT OF DRYING...HOWEVER AM A LITTLE CONCERNED ABOUT THEM CONTINUING INTO THE AFTERNOON. SECONDARY SHORTWAVE OVER MINNESOTA WILL DROP SOUTH OF THE STATE...AND LOOKS TO BE THE SUPPORT FOR 06Z RUC INVERSION HEIGHTS CLIMBING BY 1-2KFT BY 18Z. TEMPERATURES TODAY WILL BE ON THE COLDER SIDE UNDER THERMAL TROUGH...WITH LIMITED RECOVERY FROM MORNING LOWS DESPITE SOME BREAKS OF SUN IN THE AFTERNOON. SURFACE RIDGE BUILDS ACROSS THE STATE BY 12Z SATURDAY...WITH A LIGHT GRADIENT AND DRY AIRMASS LEADING TO DECENT RADIATIONAL COOLING. WE SHOULD ONLY HAVE A DUSTING OF NEW SNOW ON THE GROUND /AROUND AN INCH OR LESS/. ANY DIURNAL CU THAT FILLS IN THIS AFTERNOON WILL QUICKLY DISSIPATE EARLY THIS EVENING WITH BOTH LOSS OF SUN AND CONTINUED DRY ADVECTION...LEADING TO MOSTLY CLEAR SKIES FOR MUCH OF THE NIGHT. HEIGHTS REBUILD ON SATURDAY WITH SHORTWAVE RIDGE OVERHEAD BY 00Z SUNDAY. TEMPERATURES MAY BE SLOW TO RESPOND INITIALLY THOUGH WITH LIMITED MIXING UNTIL THE GRADIENT PICKS UP...IN ADDITION TO THE COLD START TO THE MORNING. MID/UPPER LEVEL MOISTURE INCREASES THROUGH THE DAY...LEADING TO PARTLY SUNNY SKIES BY AFTERNOON. NEXT MAJOR SYSTEM APPROACHES SATURDAY NIGHT. 00Z GFS CONTINUES THE 18Z TREND TOWARD A LESS WRAPPED UP AND MORE PROGRESSIVE SOLUTION. THE RESULTING TRACK OF THE UPPER WAVE...FAVORING MAIN ENERGY FROM THE NORTHERN STREAM THAT IS MUCH FARTHER NORTH WITH THE SHORTWAVE THAT DOES NOT PHASE INTO A LONGWAVE TROUGH. HOWEVER INITIALLY PRECIP LOOKS AS THOUGH IT WILL BE SLOWER TO START...WITH A DECENT AMOUNT OF DRY AIR IN THE LOW LEVELS THAT NEEDS TO BE OVERCOME. WILL KEEP A LOW CHANCE SATURDAY NIGHT...THEN LIKELY ON SUNDAY AS THE COLD FRONT SWINGS THROUGH. FOR NOW WILL KEEP LIKELY POPS SUNDAY EVENING UNTIL THE FRONT CLEARS EAST...BUT WITH THE MORE PROGRESSIVE TREND WILL CUT POPS OVERNIGHT SUNDAY NIGHT AND MONDAY. GFS AND ETA-XX BOTH SUPPORT HIGHER POPS FOR SUNDAY EVENING. THERE CONTINUES TO BE CONCERNS AS FAR AS PRECIP TYPE. ETA AND GFS BUFKIT BOTH INDICATE PRECIP STARTING OFF AS ALL RAIN EVEN LATE SATURDAY NIGHT. HOWEVER THERMAL PROFILES AND WEB-BELT PLOTS CONTINUE TO SUPPORT A MIX OF RAIN/SNOW INITIALLY. MIX COULD CARRY OVER INTO SUNDAY MORNING INITIALLY...HOWEVER WITH AMOUNT OF WARM ADVECTION WILL KEEP IT ALL RAIN FOR NOW. STRONG COLD ADVECTION FOLLOWS THE COLD FRONT...WHICH WILL LEAD TO A QUICK TRANSITION OVER TO ALL SNOW OVERNIGHT. WILL KEEP A LOW CHANCE FOR SNOW SHOWERS ON MONDAY WITH LINGERING CYCLONIC FLOW AT THE SURFACE AND ALOFT...HOWEVER DEEP MOISTURE REALLY DIMINISHES. WITH THIS FASTER TREND...MONDAY NIGHT NOW LOOKS LIKE THE BEST CHANCE FOR A DRY PERIOD. WILL INTRODUCE A CHANCE OF RAIN/SNOW ON TUESDAY WITH THE EARLIER APPROACH OF THE NEXT SYSTEM AS ADVERTISED BY GFS/CANADIAN/ETA-XX. && .DTX WATCHES/WARNINGS/ADVISORIES...GALE WARNING...TODAY...LAKE HURON. && $$ BRAVENDER EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 226 AM MST SAT MAR 13 2004 .DISCUSSION...FORECAST CONCERNS WILL BE HOW CLOSE WILL PRECIPITATION BE TO THE EASTERN PORTION OF THE FORECAST AREA THIS AFTERNOON..A SECOND CHANCE AT PRECIPITATION SUNDAY NIGHT...AND THE MAX TEMPERATURES THROUGH MONDAY. SATELLITE SHOWING A COMPLEX AND PROGRESSIVE UPPER FLOW FROM THE CENTRAL PACIFIC INTO NORTH AMERICA. FLOW IS TRYING TO AMPLIFY SOME OVER THE PACIFIC. THREE UPPER SYSTEMS AND HOW THEY INTERACT IS WHAT TO WORRY ABOUT INITIALLY. COMPACT SYSTEM OVER TEXAS STARTING TO MOVE QUICKLY TOWARD THE NORTHEAST AND SHOULD STAY TO THE SOUTH AND EAST OF OUR AREA. ANOTHER SYSTEM DIGGING DOWN INTO THE DESERT SOUTHWEST. THIRD SYSTEM MOVING ALONG THE UNITED STATES AND CANADIAN BORDER AND LOOKS TO BE THE SYSTEM TO MAINLY AFFECT OUR WEATHER. UPPER AIR ANALYSIS SHOWING COLD AIR NOT ANYWHERE CLOSE AT THIS TIME. AT JET LEVEL...MODELS INITIALIZED WELL. HOWEVER...THEY INITIALIZED A LITTLE LOW ON SPEEDS OF SEGMENT COMING OVER THE TOP OF THE RIDGE ALONG THE WEST COAST. THE GFS LOOKED TO HAVE THE BEST HANDLE. AT MID LEVELS...BASED ON SATELLITE...GFS HAS INITIALLY CAUGHT TEXAS SYSTEM THE BEST AND ALSO DID THE BEST ON NORTHERN SYSTEM. THE ETA LOOKS TO HAVE GOT THE NEW SOUTHWEST SYSTEM THE BEST. GFS WAS NEARLY ON THE MONEY WITH THE HEIGHT FIELD THROUGH THE CENTRAL PORTION OF THE COUNTRY. HOWEVER...IT WAS A LITTLE FAST/LOW WITH THE HEIGHTS... ESPECIALLY WITH THE NORTHERN STREAM SYSTEM. ALSO IT HAD THE MID LEVEL RIDGE OVER OUR AREA TOO STRONG BUT AGAIN WAS THE BEST OF THE MAIN THREE. THE GFS WAS TOO WET AT MID LEVELS WITH THE ETA CLOSER TO REALITY. HOWEVER...IT WAS NOT FAR ENOUGH TO THE EAST WITH THE CORRECT MOISTURE. AT LOW LEVELS...ETA/RUC ARE HANDLING THE WIND FIELD AND PRESSURE CENTER LOCATIONS THE BEST WITH A SLIGHT EDGE TO THE RUC. MODELS...ESPECIALLY THE GFS...ARE BUILDING IN PRESSURES TOO FAST BEHIND THE NORTHERN STREAM SYSTEM. ALSO THE GFS HAS PRESSURES TOO LOW AND WINDS TOO STRONG. IT ALSO HAS LEE TROUGH TOO FAR EAST WITH THE ETA/RUC THE SLOWEST. SLOWER SOLUTION IS BETTER DUE TO STRONG CROSS MOUNTAIN COMPONENT. SOME DISCREPANCY IN THE STRATUS/MOISTURE FIELD. THE BOUNDARY LAYER RELATIVE HUMIDITY WOULD SAY THAT THE GFS AND RUC HAVE A BETTER FEEL OF THE LOW LEVEL MOISTURE. HOWEVER...THE RUC/ETA HAVE A BETTER HANDLE ON LOW LEVEL DEWPOINTS. CURRENTLY RUC IS DOING THE BEST. ETA LOOKS TO BE DOING BETTER ON 850 MB TEMPERATURES. RIGHT NOW WILL GO WITH THE RUC LOW LEVEL DEWPOINT AND WIND FIELDS INTO THE AFTERNOON AND THEN GO WITH THE ETA AFTER THAT. BASED ON NATIONAL DISCUSSIONS...JET FORECASTS... AND RECENT BIASES...THINK A BLEND OF THE FASTER GFS AND THE NOT AS DEEP ETA WOULD BE IN ORDER AT MID AND UPPER LEVELS. FOR TODAY/TONIGHT...LIKE THE SLOWER/FURTHER WEST LEE TROUGH OF THE ETA/RUC DUE TO STRONG WESTERLY FLOW. THIS WILL ALLOW FOR A BETTER WARMUP FURTHER SOUTH AND EAST. WILL HAVE A VERY WARM START ESPECIALLY IN SOUTHERN AND EASTERN LOCATIONS. HOW MUCH CLOUD COVER WILL BE MAIN FACTOR ON HOW MUCH TEMPERATURES ARE HELD DOWN. AT THIS TIME...THINK CLOUD COVER WILL CLEAR OUT PRETTY FAST. PLAN ON GOING NEAR THE SLIGHTLY WARMER ETA MOS/2 METER TEMPS FOR MAXES. WEAK JET DYNAMICS STAY TO THE NORTH. BEST LOW LEVEL MOISTURE AND INSTABILITY HUG THE EXTREME SOUTHEAST PORTION OF THE FORECAST AREA BY 00Z. HOWEVER...BEST MID LEVEL MOISTURE AND 850 MB TO 700 MB THETA E RIDGE ARE EAST OF THE AREA AS MAIN TROUGH HAS WORKED ITS WAY THROUGH. SO WILL KEEP EASTERN SECTIONS DRY...BUT DAY CREW WILL HAVE TO WATCH IT CLOSELY. WINDS DROP OFF LATE WITH LITTLE CLOUD COVER EXPECTED AT THIS TIME. SO PLAN ON GOING SLIGHTLY BELOW GUIDANCE. FOR SUNDAY/SUNDAY NIGHT...STAY IN SUBSIDENCE FROM THE JET THROUGH THE DAY...AND THEN MODELS START TO DIVERGE SOME DURING THE NIGHT PER DISCUSSION ABOVE. THINK MAIN DYNAMICS AND JET WILL BE FURTHER NORTH DURING THE NIGHT. ALSO AIR MASS FROM THE SURFACE THROUGH MID LEVELS WILL BE VERY DRY BEHIND DEPARTING NORTHERN SYSTEM. MODELS PRODUCE SOME PRECIPITATION BUT THINK THIS IS OVERDONE AND WILL LEAVE THE NIGHT PERIOD DRY AT THIS TIME. START OUT LIGHT DOWNSLOPE DURING THE DAY THE WARM AIR ADVECTION INCREASES DURING THE DAY. ETA/MAV MOS SIMILAR TO ETA 2 METER. TREND RECENTLY HAS BEEN FOR THIS TO BE SLIGHTLY COOL THOUGH. WILL GO NEAR TO SLIGHTLY ABOVE. FOR MONDAY/MONDAY NIGHT...DEPENDING ON WHICH MODEL YOU CHOOSE...MAIN JET REMAINS TO THE NORTH WITH AREA MOSTLY IN SUBSIDENCE. WILL GO FOR LESS DYNAMICS...CLOUDS...AND COLD AIR. THIS HAS ALSO FIT WITH RECENT TREND OF MODEL BEING TOO COOL. WILL GO ABOVE THE MAV MOS AND CLOSER TO THE ETA 2 METER. NO CHANGES PLANNED FOR THE 4 TO 7 DAY PERIOD AT THIS TIME. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ BULLER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DODGE CITY KS 252 AM CST SAT MAR 13 2004 .DISCUSSION... DAYS 1-2... SOUTHERN BRANCH UPPER TROF WAS LOCATED NEAR EL PASO THIS MORNING WITH ALL MODELS IN GOOD AGREEMENT TAKING THIS SYSTEM NORTHEAST INTO WESTERN OKLAHOMA BY 18Z, THEN MOVE IT EAST OF THE AREA DURING THE AFTERNOON. AS THIS SYSTEM PASSES TO OUR EAST MOISTURE AND CLOUDS WILL GET SHUNTED EASTWARD AND WITH SUBSIDENCE BEHIND THIS SYSTEM APPEARS OUR FRONT WHICH WILL BE MOVING SOUTH ACROSS THE CWA TONIGHT WILL BE A DRY FROPA. ETA DOES HINT AT SOME LOW LEVEL MOISTURE AND WEAK LIFT WHERE WE WILL HAVE SOME UPSLOPE FLOW EARLY SUNDAY JUST WEST OF THE AREA. SHOULD SEE A RETURN OF CLOUDS BUT LIFT TOO WEAK TO INTRODUCE SMALL POPS. AS FOR TEMPS WILL FOLLOW 85H TEMP TREND WHICH SUPPORTS CURRENT FORECAST OF 50S ACROSS THE CWA. AS FOR TODAY, PCPN MOVING INTO AMA CWA CONTINUES TO TRACK NORTHWARD. RADAR TRENDS DO SHOW A WEAKENING TREND WITH THE PCPN ON THE NORTHWESTERN EDGE. RUC STILL SHOWING OUR SE CWA BEING THE MOST FAVORABLE AREA THIS MORNING SO WILL KEEP CHC POPS HERE BUT GIVEN THE CURRENT RADAR TRENDS WILL INTRODUCE SMALL POPS ALONG ALL OF OUR SOUTHERN TIER. AS FOR TEMPS GIVEN SOME CLEARING DEVELOPING DURING THE AFTERNOON OVER OUR WESTERN CWA AND 85H TEMP PROGGED AT 00Z SUN EXPECTING AFTERNOON HIGHS A FEW DEGREES WARMER THAN YESTERDAY. AS A RESULT MID 60S STILL APPEAR REASONABLE OVER OUR WEST WHILE WILL KEEP TEMPS AROUND 5F COOLER IN THE EAST WHERE CLOUDS LINGER LONGER. DAYS 3-7... ONLY MINOR TWEAKS TO GOING EXTENDED. && .PRELIMINARY POINT TEMPS/POPS... DDC 63 32 56 31 / 00 00 00 00 GCK 65 29 56 29 / 00 00 00 00 EHA 65 29 59 30 / 00 00 00 00 LBL 64 29 58 29 / 00 00 00 00 HYS 63 31 55 30 / 00 00 00 00 P28 59 35 56 34 / 40 00 00 00 && .DDC WATCHES/WARNINGS/ADVISORIES... KS...NONE. && $$ 18/15 ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 325 AM EST SAT MAR 13 2004 .SHORT TERM... OUR PRIMARY FORECAST CHALLENGE IS TO DETERMINE PRECIPITATION TYPE TONIGHT AND SUNDAY. AT 07Z THE SFC WX MAP SHOWS A HIGH PRESSURE RIDGE OVER OUR AREA AND SKIES HAVE CLEARED. WE'LL START THE DAY OFF WITH PLENTY OF SUN. THE IR SAT LOOP SHOWS HIGH CLOUDS ACROSS MN AND MOST OF WI, THIS WILL GRADUALLY MOVE IN FROM THE WNW THROUGH THE DAY THOUGH WE'LL STILL GET A LOT OF SUN. A LOW PRESSURE SYSTEM WILL TRACK ALONG THE MN AND CANADIAN BORDER TONIGHT AND A COLD FRONT WILL APPROACH OUR REGION FROM THE WEST. CLOUDS WILL THICKEN IN ADVANCE OF THIS FEATURE AND PRECIPITATION WILL BREAK OUT ACROSS OUR CWA LATE TONIGHT (MAINLY AFTER MIDNIGHT). DETERMINING PCPN TYPE TONIGHT IS VERY TRICKY. AN INITIAL LOOK AT NUMERICAL GUIDANCE WOULD INDICATE MAINLY RAIN FOR MOST OF OUR CWA, AND THE BUFKIT DATA ALSO SUGGESTS THIS. THE OVERALL WX PATTERN SHOWING INCREASING SOUTHERLY FLOW ACROSS OUR AREA WOULD ALSO IMPLY MILDER TEMPS AND RAIN. HOWEVER, A CLOSER LOOK AT FORECAST ETA AND GFS SOUNDINGS AND WET BULB TEMPS INDICATES WE'LL HAVE MIXED RAIN AND SNOW ACROSS MUCH OF OUR CWA. THE ETA IS SHOWING IT'S BALDWIN FAILURE SCHEME IN PROGGING -FZRA IN SOME LOCATIONS WHILE THE FORECAST SOUNDING SUPPORTS ALL SNOW. WE PREFER GFS FORECAST SOUNDINGS, PROGGED CRITICAL THICKNESS VALUES AND ALSO THE 10 KM RUC FORECAST FOR PCPN TYPE. THEY SUGGEST PCPN SHOULD FALL IN THE FORM OF PLAIN -RA TONIGHT ACROSS OUR EXTREME SOUTHERN AND SOUTHWESTERN CWA. A LITTLE FARTHER NE OF THAT AREA, WE'LL GO WITH -RASN. ACROSS OUR NORTHERN CWA, WE'LL GO WITH ALL SNOW (ACCUMS LESS THAN AN INCH). ON SUNDAY, LOW LEVEL FLOW WILL BEGIN TO VEER MORE TO THE SW AS THE FRONT DRAWS NEAR. AS THAT HAPPENS AND WE PULL AIR OFF THE WATER WE EXPECT OUR NORTHERN LAKESHORE COUNTIES TO SEE LIGHT SNOW BECOMING MIXED WITH LIGHT RAIN, PLAIN -RA ACROSS OUR SOUTHERN CWA, AND -SN OVER OUR NE COUNTIES. ONCE AGAIN, WE'RE FOLLOWING THE 10KM RUC P-TYPE PRETTY CLOSELY HERE. MOST OF THE PCPN WILL FALL SUNDAY MORNING. FORTUNATELY, QPF'S ARE RELATIVELY LIGHT, SO WE SHOULDN'T HAVE TOO MANY PROBLEMS AND CERTAINLY NO HEADLINE CONCERNS. BY SUNDAY NIGHT, COLDER AIR WILL GRADUALLY FILTER IN BEHIND THAT FRONT. ETA GUIDANCE LOOKS DRY FOR SUNDAY NIGHT, WHILE GFS SHOWS LIGHT QPF'S OVER OUR AREA. ONCE AGAIN WE PREFER THE GFS, THINKING WITH THE LOW LEVEL MOISTURE HANGING AROUND AND 500 MB TROF AXIS MOVING OVERHEAD, WE'LL HAVE A CHANCE FOR LIGHT SNOW OVERNIGHT. BY MONDAY, THE UPPER TROUGH AXIS WILL MOVE EAST OF OUR AREA AND A SFC HIGH PRESSURE RIDGE WILL BUILD IN. THEREFORE, WE'RE GOING TO GO WITH A DRY FORECAST THOUGH SKIES WILL REMAIN MOSTLY CLOUDY. .LONG TERM... SHORT WAVE THAT DIVES INTO THE GREAT LAKES REGION THIS WEEKEND WILL DIG A LONGWAVE TROUGH OVER THE AREA INTO THE UPCOMING WORK WEEK. DECENT CHANCES FOR PRECIPITATION WILL EXIST EACH DAY WITH SHORTWAVE/S PARADING THROUGH THE FLOW. THE GFS AND THE CANADIAN HAVE TRENDED COLDER WITH THE SYSTEM THAT MOVES INTO THE REGION IN THE MIDDLE OF THE WEEK. WILL TREND PRECIPITATION IN THE TUESDAY AND WEDNESDAY TIME FRAME MORE TOWARD THE FROZEN KIND. IT DOES APPEAR THAT SOME WARMING OCCURS INTO THE UPCOMING WEEKEND AS THE FLOW BECOMES MORE ZONAL. && .GRR...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ LAURENS DUKE mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 330 AM CST SAT MAR 13 2004 .SHORT TERM...TODAY THROUGH MONDAY NIGHT FORECAST CONCERNS ARE STILL WINDS AND PRECIPITATION SATURDAY INTO SUNDAY. SHOULD START OUT PRETTY WARM THIS MORNING AS NICE SOUTH WIND HAS KEPT MOST TEMPERATURES NEAR 40. LOOKS LIKE FRONTAL PASSAGE MOST OF CWA BY 18 UTC...AND THEN PRETTY IMPRESSIVE SURFACE WINDS KICK UP BEHIND FRONT. WILL GO WITH ADVISORY TIMED ACROSS ENTIRE CWA FOR GUSTS TO NEAR 45 MPH. ONLY CONCERN IS FAR SOUTHWEST...WHERE DRIER AIR AND STEEPER LAPSE RATES MAY ALLOW A DEEPER MIXING...BUT THIS AREA IS NOT IN THE BEST GRADIENT...SO THINK ADVISORY SHOULD COVER IT...BUT BEARS WATCHING. NEXT CONCERN IS PRECIP POTENTIAL WITH FRONT AND POST FRONTAL. ALL INDICATIONS ARE OF A VERY DRY LOWER ATMOSPHERE. DYNAMICS MOVE THROUGH SO FAST THAT MAY NOT HAVE ENOUGH TIME TO FULLY SATURATE COLUMN. BUFR SOUNDINGS FROM ETA AND RUC BUFKIT SOUNDINGS ALL POINT THIS OUT. CURRENT PACKAGE HAS PRECIP CONFINED MOSTLY TO NORTHERN CWA...AND OTHER THAN TRIMMING BACK STARTING TIME A FEW HOURS TO ACCOUNT FOR MORE DRY AIR...LEFT AREAL COVERAGE THE SAME. DID MAKE THE CHANGE TO AN ALL LIQUID EVENT WITH LATER START TIME. POST FRONTAL COOLING ALOFT STEEPENS LAPSE RATES ENOUGH TO WARRANT CONTINUED MENTION OF SNOW SHOWERS EASTERN CWA TONIGHT...BUT NOTHING TOO IMPRESSIVE AS AIR BEHIND FRONT IS EXTREMELY DRY. BRIEF REPRIEVE SUNDAY FROM PRECIP CHANCES...AND EVEN WITH CONTINUED NORTHWEST FLOW...BUMPED TEMPERATURES UP WITH DECREASING CLOUDS AND DRY AIR...TEMPS SHOULD RISE FAIRLY WELL WITH ALMOST 12 HOURS OF SUNSHINE. NICE CHANGE OF PACE EARLY MONDAY MORNING AS WEATHER SYSTEM ACTUALLY APPROACHES FROM SOUTHWEST FOR ONCE. MORE OF AN INVERTED TROF FEATURE...BUT ENOUGH MOISTURE AVAILABLE...WITH COOL TEMPERATURES...TO MENTION SNOW MONDAY MORNING THROUGH EVENING. .LONG TERM...TUESDAY THROUGH SATURDAY MEDIUM RANGE MODELS ARE STILL HAVING TROUBLE LATCHING ONTO A GOOD SOLUTION DURING THIS PERIOD. WILL CONTINUE TO KEEP THE FORECAST MORE GENERAL UNTIL TIMING ISSUES BECOME CLEAR. PERIOD OPENS WITH AN H5 WAVE MOVING TOWARD THE AREA IN FAST NORTHWEST FLOW. IF THIS SOLUTION PANS OUT THE SURFACE REFLECTION WILL MOVE JUST TO THE EAST OF THIS AREA AND WILL BRING A CHANCE OF RAIN OR SNOW TUESDAY AFTERNOON. THE CHANCE WILL EXTEND AT LEAST UNTIL WEDNESDAY AFTERNOON AND THE PRECIPITATION TYPE WILL CHANGE TO ALL SNOW AS THE COLD AIR WORKS INTO THE REGION BEHIND THE LOW. ANOTHER WAVE QUICKLY FOLLOWS THE FIRST ONE BUT THIS ONE WILL MOVE FARTHER EAST AS THE UPPER FLOW BECOMES ZONAL AND THE WEATHER MAKERS MOVE BY TO THE NORTH. MADE FEW CHANGES TO THE GOING GRIDS. DID MOVE UP THE START TIME OF THE RAIN OR SNOW TO 12Z TUESDAY. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...WIND ADVISORY ENTIRE AREA TODAY AND TONIGHT. MN...WIND ADVISORY LATE TODAY THROUGH TONIGHT. $$ HARDING/KEEFE sd AREA FORECAST DISCUSSION...CORRECTION NATIONAL WEATHER SERVICE CHICAGO IL 600 AM CST SAT MAR 13 2004 .AVIATION DISCUSSION FOR 12Z TAFS... SURFACE RIDGE AXIS CURRENTLY EXTENDS FROM OHIO VALLEY INTO NORTHERN LOWER MICHIGAN. WATER VAPOR IMAGERY DEPICTING NEXT WAVE ACROSS EASTERN MONTANA TO AFFECT AREA LATER TONIGHT. LOW/MID LEVEL PROFILER WINDS ACROSS CENTRAL PLAINS SHOWING STRONG SOUTHWEST COMPONENT WITH GOOD LOW/MID LEVEL WAA AHEAD OF THIS WAVE. MID CLOUD COVERAGE HAS INCREASED THROUGHOUT THE NIGHT ACROSS WESTERN IA WHICH COMPARES FAVORABLY TO RUC/MESOETA MID LEVEL RH PROGS. THIS BAND OF MID CLOUD SHOULD APPROACH WESTERN COUNTIES OF CWA BY LATE MORNING AND OVERSPREAD REMAINDER OF NORTHERN IL/NORTHWEST IN EARLY IN THE AFTERNOON. LIGHT AND VARIABLE WINDS THIS MORNING WILL INCREASE INTO THE 15 TO 20 KNOT RANGE INTO THE AFTERNOON AS SFC PRESSURE GRADIENT TIGHTENS AND PRESSURE FALL BUBBLE ACROSS WESTERN MINNESOTA SHIFTS EAST. LOW/MID LEVELS CONTINUE TO SATURATE TONIGHT WITH ETA/GFS TIME SECTIONS SHOWING STRONGEST MID LEVEL LIFT IN THE 04Z-07Z PERIOD. HAVE INTRODUCED RAIN SHOWERS IN THE TAF BY LATE EVENING WITH ONSET OF MVFR CIGS IN THE 07Z-10Z TIME FRAME. NDM && .DISCUSSION REGARDING 400 AM ZONES/GRIDS: LTL TO BE CONCERNED WITH TDY AS SFC HI PRES CONTS TO MOVE EWD THRU UPR OH VLY AND NXT STORM SYS STILL WELL TO W. SHOULD BE A RELATIVELY PLEASANT DAY WITH AMPLE MORNING SUNSHINE AND WAA PATN ALLOWING MUCH BETTER DIURNAL TEMP JUMP THIS MORNING. MID/HIGH LVL CLOUDS TO BEGIN INCRSG IN COVG THIS AFTN...BUT STILL ENUF SUN TO ALLOW HIGH TEMPS TO MODERATE TO ABV SEASONAL NORMS. WATER VAP IMAGERY SHOWS CENTER OF NLY BRANCH S/W MOVG SLGTLY S OF DUE E ACRS SRN SASK...AND ENERGETIC SRN BRANCH VORT CENTER LOCATED INVOF AMA AT 0900Z. MODELS IN FAIRLY CLOSE AGREEMENT IN LIFTING SRN PLAINS SYS NEWD AND MERGING ITS MOISTURE FIELD WITH AMPLIFYING TROF TO N. DECENT ISENTROPIC UPGLIDE RESULTS AND GUID BRINGS STGR OMEGA FIELD INTO FA LATE THIS EVENING. BASED ON SATLT IMAGERY AND MODEL CONSISTENCY...WILL GO WITH UNQUALIFIED POPS FOR TNGT ACRS ENTR FA. WILL KEEP CHC AND LIKELY POPS INTO SUN MRNG AHD OF ASSOCIATED CDFNT AND DRY SLOT. RGN THEN UNDERGOES INCRSG COLD ADVCN AS LO PRES DEEPENS OVR LK SUP...LEADING TO BLUSTERY AND COLDER CONDITIONS SUN AFTN/EVENING. WRAP ARND STRATOCU FCST TO SPREAD SWD INTO RGN SUN AFTN/EVENING SO WILL MENTION CHC FLRYS AS H85 TEMPS LWR TO ARND -8 C BY 00Z MON. TRANQUIL DAY MON...THEN BOTH GFS AND ETA PICK UP ON ANOTHER...WEAKER DSTBC MOVG ESEWD INTO LWR MO VLY MON NGT-TUES. THIS WILL INCRS CLOUDINESS AGAIN...BUT ATTM IT APPEARS BEST VERTICAL VELOCITY WILL PASS S OF FA SO WILL HAVE NO MENTION OF PCPN ASSD WITH THIS SYS. MORE IMPRESSIVE DIGGING S/W FCST BY GFS TO MOVE SEWD INTO MID MS VLY ABOUT WED...WITH 00Z RUN TRACKING 34 UNIT VORT CENTER JUST S OF FA. IF THIS ACTUALLY MATERIALIZES...THREAT OF SNOW WOULD BEGIN BY WED MRNG AND CONT INTO WED EVENING. STILL LOOKS LIKE MODERATION BY LATE IN EXTENDED PERIOD THOUGH. AFTER MID WEEK SYS MOVES THRU...LARGE H5 TROF FCST TO RETROGRADE OFF THE COAST OF BC...INDUCING ZONAL FLOW INTO NOAM...AND RESULTING IN SIG SPRINGLIKE WARMING ACROSS MOST OF CONUS TOWARD END OF NXT WEEK. MERZLOCK && .LOT...WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE LK MI...GALE WRNG NRN LK MI TONIGHT. $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1145 AM EST SAT MAR 13 2004 .DISCUSSION... DEEPENING SHORTWAVE TROUGH SLIPPING ESE ALONG MANITOBA/ND BORDER. UPR SYSTEM COMPACT AS HT FALLS OBSERVED AS FAR E AS DAKOTAS WITH SIG HT RISES NOTED ON KINL/KGRB/KAPX 12Z SOUNDINGS...SOME 150M AT H5. WIDE RIBBON OF ISENTROPIC ASCENT ON 280-290K SFC (H9-H7) SPREADING INTO UPR MI ATTM. CLOSEST PCPN HAS BEEN OBSERVED IN WCNTRL-NW WI AND FAR NRN MN. LIGHTNING DETECTION NETWORK PICKING UP SOME LIGHTNING STRIKES OVR N MN AND NEAR ST CROIX RIVER VALLEY ALONG WI/MN BORDER. STRONG TEMPERATURE/MOISTURE TRANSPORT RUSHING NE ON 40-50KT JET IN 950MB-850MB LAYER. FOLLOWING 12Z ETA/RUC AND LATEST RADAR TRENDS EXPECT PCPN TO BREAK OUT OVR SWRN CWA AROUND 18Z...AND INTO CNTRL ZONES BY 21Z. LARGE ELEVATED WARM LAYER TURNING UP ON SOUNDINGS FM BIS/MPX AND RUC/ETA NOW SHOWING PTYPE MAY BE A LARGER FOR OUR S ZONES. HAVE BROUGHT RA/SN LINE FARTHER N INTO WI BORDER ZONES...BUT DRY AIR EVIDENT ON GRB SOUNDING SHOULD KEEP PTYPE MAINLY SNOW FOR N 2/3 OF CWA. RUC/ETA PAINT UP TO 0.4 OF QPF THROUGH 00Z. MAYBE A BIT AGRESSIVE...BUT WITH SUCH STRONG THETE-E ADVECTION AND LOWER LEVEL JET...MAYBE NOT. BASED ON REFLECTIVITIES BLOSSOMING ACROSS W HALF OF WI...AND SFC OBS SHOWING PCPN IS REACHING GROUND (AS LOW AS 3/4 -SN AT PARK FALLS, WI) WILL START HEADLINES A FEW HOURS SOONER ACROSS ENTIRE CWA. QPF STILL POINTS TO GENERAL 4-7" FOR SNOW...BUT CUT THAT ALONG BORDER WITH RA/SN MIX MORE DOMINANT. BEST INSTABILITY LOOKS TO STAY W THIS AFTN SO...NO THUNDER MENTIONED IN GRIDS/ZONES ATTM. UPDATED GRIDS OUT...ZFP COMING SHORTLY. && .MQT WATCHES/WARNINGS/ADVISORIES... SNOW ADVY MIZ001>005-009-084 FROM 18Z THRU TONIGHT. WINTER WX ADVY MIZ010>012 FROM 18Z THRU TONIGHT. SNOW ADVY MIZ006-007-014-085 FROM 21Z THRU 13Z SUN. WINTER WX ADVY MIZ013 FROM 21Z THRU 13Z SUN. GALE WARNING LAKE SUPERIOR. && $$ JLA mi