AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 940 AM EST MON MAR 13 2000 SYNOPSIS: HIGH PRESSURE WILL BUILD ACROSS THE STATE TODAY AND TONIGHT THEN MOVE SOUTHEAST OF THE REGION ON TUESDAY. A WEAK LOW PRESSURE DISTURBANCE WILL APPROACH THE AREA ON TUESDAY. TECHNICAL DISCUSSION: LOTS OF SUNSHINE AT THE MOMENT THROUGHOUT FA. HOWEVER...SAT SHOWS AREA OF CI OVER SW ME ASSOCIATED WITH VORT MAX. AIRMASS QUITE DRY AND DOWNSLOPE TO THE E OF MNTNS SHLD SERVE TO DSPT SOME OF THE CLDS. WILL GO PRTLY SNY ACRS DOWNEAST ME IN DEFERENCE TO CLDS MOVG THEIR WAY...BUT KEEP MSTLY SNY GOING UP N. CAA WILL CONT THRUT DAY... BUT STRONG MARCH SUN SHLD STILL ALLOW TEMPS TO RECOVER SOME. MAX TEMPS WILL RANGE FROM MID 20S OVER N TO GENLY 30S DOWNEAST. GENLY CLR AND COLD OVERNIGHT UNDER SFC RIDGE. WAA ON TUE WILL GENERATE CLDS AND PERHAPS SOME AFTN SNOW SHWRS. COASTAL WATERS...WILL DOWNGRADE GALE WARNING TO A SMALL CRAFT BASED ON CURRENT OBSERVATIONS AND RUC WIND FCST. .CAR...SMALL CRAFT ADVSRY IN EFFECT GABRIC me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1043 PM EST MON MAR 13 2000 CURRENT SFC ANALYSIS INDICATES WEAK WARM FRONTAL BOUNDARY ACROSS FAR NRN LWR MI...BASICALLY FROM THE STRAITS REGION ESE TO ROGERS CITY. 900-500 MB CLOUDS HAVE SCATTERED OUT SOUTH OF THIS FRONT AS PER SATELLITE IR LOOPS...WHICH PROMPTED THE EARLY EVENING UPDATE TO REMOVE STEADY PRECIPITATION FROM THE NRN LWR MI ZONES. HOWEVER... PLENTY OF LOW CLOUDS REMAIN AS HIGHER (32F-PLUS) DEWPOINTS ADVECT IN S OF THE WARM FRONT. MAIN FORECAST CONCERNS OVERNIGHT WILL BE WITH THE CLOUD COVER EXTENT... THE THREAT FOR FREEZING DRIZZLE...AND WHETHER OR NOT MEASURABLE PRECIP WILL MAKE IT BACK INTO THE REGION BEFORE DAYBREAK. MID LEVEL DRY SLOTTING S OF THE WARM FRONT IS ALSO EVIDENCED WITH THE LATEST WV LOOPS. KGRB/KAPX REGIONAL RADAR LOOPS SHOW MINIMAL REFLECTIVITIES (JUST ABOVE 0 DBZ)...MAINLY ALONG AND N OF THE WARM FRONT. LATEST (00Z) ETA CONTINUES THE TREND FROM THE PRIOR 18Z ETA RUN AND THE 21Z/00Z RUC...WITH THE REGION TO REMAIN BASICALLY DRY-SLOTTED OVERNIGHT WITH...IF ANYTHING...MORE DOWNWARD Q-G FORCING (WEAK RFQ JET UPPER CONVERGENCE AND 850-500 MB Q-VECTOR DIVERGENCE). WHILE MODEL SOUNDINGS DO SHOW A RELATIVELY MOIST 1000-500 MB LAYER (MEAN RH'S NEAR 70 PERCENT)...DEWPOINT DEPRESSIONS AT ANY GIVEN LEVEL ARE GENERALLY NO LOWER THAN 5F. LACK OF DEEP MOISTURE/ICE SEEDING WILL NEGATE CHANCES FOR ANYTHING MORE THAN FLURRIES OR DRIZZLE. IN ADDITION...WIND SHEAR IN THE LOWER CLOUD TOPS IS QUITE WEAK FOR COALESCENCE AND (THUS) DRIZZLE FORMATION. GIVEN THIS...ALONG WITH VERY SHALLOW LOW LEVEL MOISTURE (GENERALLY THROUGH 1000 FEET AGL)...AM INCLINED TO TAKE DRIZZLE/ FREEZING DRIZZLE MENTION OUT OF THE ZONES. HAD BOOSTED OVERNIGHT LOW TEMPS WITH EARLIER ZONE UPDATE GIVEN THE SW FLOW/LOW-LEVEL MIXING BEHIND THE WARM FRONT...AT THIS POINT ANTICIPATE ONLY MINOR ADJUSTMENTS (IF ANY). .APX...NONE. HURLEY mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1005 PM EST MON MAR 13 2000 ...WILL UPDATE TO BRING PARTIAL CLEARING IN OVERNIGHT... SINCE THE LAKE TEMPERATURE IS NOT FAR FROM THE AIR TEMPERATURE AND SINCE VISIBILITIES HAVE IMPROVED OVER CNTL WI THIS EVENING AFTER THE CLEARING MOVED IN... PARTIAL CLEARING SEEMS TO FORECAST OF CHOICE. GOING ALONG WITH THIS IS THE 925 RH ON RUC... WHERE THE 90 PCT RH MATCHED THE SC CLOUD FIELD VERY NICELY AT 02Z. THIS SAME MODEL BRINGS THE CLEARING ACROSS THE CWA OVERNIGHT. IN FACT... SKIES HAVE CLEARED N OF MKG BY 02Z. WINDS AT 925 MB INCREASE FROM 15 KNOTS TO 25 KNOTS OVERNIGHT AND THAT SHOULD INCREASE THE MECHANICAL MIXING WHICH SHOULD HELP KEEP FOG FROM GETTING TO WIDESPREAD. BOTTOM LINE WILL UPDATE TO PARTIAL CLEARING WITH AREAS OF FOG ACROSS GRR CWA OVERNIGHT. WILL HAVE LOWS NEAR 30 NORTHEAST AND 30 TO 35 ELSEWHERE. .GRR...NONE. WDM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 400 PM EST MON MAR 13 2000 PROGRESSIVE PATTERN TO CONTINUE THIS FCST PERIOD ACROSS THE GRTLKS/ UPR MIDWEST WITH FAST NW FLOW ALOFT GRADUALLY DVLPNG GREATER AMPLITUDE AS POLAR VORTEX OVR HUDSON BAY ELONGATES TO THE SOUTH BY 72 HRS AND BEYOND. FIRST IN A SERIES OF WEAK WAVES MOVG ALONG TIGHT BAROCLINIC ZONE XTNDNG FROM CANADIAN ROCKIES TO UPR MISS VALLEY/ WRN GRTLKS MOVG ALONG MN/ONTARIO BORDER ATTM. POCKETS OF VRY LGT SNOW PER DLH/MQT 88D/S ARE ASSCTD WITH VRY WEAK ISENT LIFT IN WAA PATTERN OVR NRN MN/XTREME NW WIS COMBINED WITH MODEST LOW LVL CONVERGENCE PER RUC STREAMLINE ANAL. AIRMASS IN THE LOW LVLS OVR UPR MI VRY DRY HWVR PER MODEL SOUNDINGS AND CURRENT SFC DWPTS IN THE MID TEENS TO LOW 20S. AS A RESULT AS WEAK SFC LOW PASSES N OF LK SUPERIOR TNGT AND DRAGS TROF ACROSS U.P. FM WEST TO EAST XPECT BRIEF DURATION VRY LGT SNOW/FLURRY EVENT. DRY LOW LVLS WILL LIMIT SNOWFALL TO THE NUISANCE CATEGORY WITH ONLY A LGT DUSTING AT BEST. NEXT IN SERIES OF WEAK SFC WAVES CURRENTLY FORMING OVR NODAK WILL SLIDE ESE IN RESPONSE TO UPR LVL VORT IN NW FLOW ALOFT AFFECTING UPR MI TUES. AS VORT SHEARS OUT UPR LVL HGTS FALL 24-36 HRS WITH SOMEWHAT MORE IMPRESSIVE LOBE OF MOISTURE ADVECTING ESE ON I285 K THETA SFC. FORCING VERY MINIMAL HWVR WITH NEUTRAL PRES ADVECTION ON 285K SFC AND BEST DIFF PVA WITH VORT REMAINING TO THE NORTH OF LK SUPERIOR. VORT AND ASSCTD SFC CDFNT DOES DRAG DOWN SLGTLY COLDER AIR LATER ON TUES WITH LAKE TO 850 MB DELTA-T/S LOWERING TO 13-14 DEG C. MAY SEE A BRIEF PERIOD OF LAKE ENHANCED SNOW IN 290 FLOW WITH PASSAGE OF SFC BNDRY AND UPR LVL SUPPORT BEFORE INVERSION HGTS LWR LATE IN THE DAY. WITH INVERSIONS DROPPING TO 4K FT BY 00Z AND THERMAL INSTABILITY ONLY MARGINAL (DELTA T/S REMAINING ARND 14 DEG C) DO NOT SEE PURE LAKE EFFECT EVENT HAPPENING UNTIL COLDER AIR COMES DOWN AFTER NEXT MORE POTENT WAVE WED-WED NGT. WILL CONFINE MENTION OF SNOW TO NUISANCE CATEGORY AGAIN TUES DESPITE WEAK Q-G FRONTOGENESIS ALONG BAROCLINIC ZONE AND POTENTIAL FOR LAKE ENHANCEMENT OVER MAINLY THE KEWEENAW. WITH GOOD MID LVL DRYING AND MODEST SUBSIDENCE AND ONLY MARGINAL LAKE INSTABILITY TUES NGT WILL FCST ONLY LAKE CLDS AND FLURRIES NR THE LAKE WITH CONSIDERABLE BREAKS INLAND. XPECT MIN TEMPS WILL BE WIDE RANGING WITH WEAK SFC RIDGE MOVG OVHD AND VARYING CLD CONDITIONS. MOST INTERESTING SCENARIO SETTING UP FOR WED WITH MORE SIGNIFICANT UPR LVL VORT MAX MOVG ACROSS THE PLAINS WITH CLIPPER LOW DROPPING ACROSS THE PRAIRIE PROVINCES. STRONG ISENT LIFT DVLPNG IN STRONG LOW LVL WAA ON I290-I285 THETA SFCS COMBINED WITH GOOD Q-G FORCING ASSCTD WITH DIFF PVA AHEAD OF VORT MAX AND LEFT EXIT REGION OF APRCHNG UPR LVL JET STREAK SHUD CAUSE PRECIP TO BREAK OUT OVR THE FAR WRN U.P. ARND DAYBREAK WED. SHALLOW ABV FREZ LAYER WARM ADVECTS INTO THE SRN U.P. DURING THE DAY COMBINED WITH DIURNAL MID MARCH HEATING COULD RESULT IN A RAIN/SNOW MIX OVR ABT THE SRN 1/3 OF THE U.P. THURS. MODELS STILL QUITE UNCERTAIN AS TO DEGREE OF WARMING AND SPEED OF THE VORT. HAVE LEANED TWRD SLGTLY WARMER AVN/ETA SOLN FOR TEMPS/THICKNESS/PRECIP TYPE FCST AND SLGTLY SLOWER ETA/NGM SOLN FOR TIMING OF SFC LOW/UPR LVL VORT GIVEN AVN/S RECENT TENDENCY TO OVRDVLP UPR LVL VORTS. HWVR LATER FCSTS WILL HAVE TO REFINE WED'S FCST. .MQT...NONE. ED F mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 930 PM CST MON MAR 13 2000 CONCERNED WITH PRECIP CHANCES OVERNITE INTO TUES. NEWEST ETA/NGM/RUC ALL LOOK SLOWER AND DEEPER WITH NW FLOW S/W...THUS TIMING OF PRECIP LOOKS DIFFERENT. MODELS NOW BRING MORE LIFT ACROSS CWA WITH S/W...STRONGEST LIFT AROUND 18Z. THEREFORE WILL UPDATE ZFP...GOING CLDY AND INTRODUCE CHANCE POPS FOR 2ND PD. WITH SLOWER SYSTEM WILL ALSO SCALE BACK 1ST PERIOD PRECIP. .EAX...NONE. RAS mo FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 847 PM CST MON MAR 13 2000 SFC ANALYSIS AND MSAS DATA SHOWS HIGH PRESSURE BUILDING SLOWLY INTO THE NRN PLAINS THIS EVENING. DRIER AIR HAVING A DIFFICULT TIME IN SAGGING SOUTH INTO THE FA PER MSAS DATA HOWEVER LATEST SATELLITE TRENDS DO SHOW BREAKS IN THE LOW LEVEL CLOUD COVER EXTENDING NW TO SE ACROSS THE AREA. MID AND HIGH CLOUDS THINNING OUT SLIGHTLY AS WELL...BUT NOT ENOUGH TO WARRANT CHANGING MOSTLY CLOUDY FORECAST FOR MOST OF THE FA. LIGHT SNOW/FLURRY ACTIVITY HAS MOSTLY COME TO AN END AS 280K ISENTROPIC DOWNGLIDE SETS UP AND 850 TO 500 MB Q VECTOR DIVERGENCE INCREASES. THIS REFLECTED BY LATEST REGIONAL 88D TRENDS. WILL HOWEVER KEEP MENTION OF FLURRIES GOING AS FLURRIES REPORTED OVER SE SASKATCHEWAN IN AREA OF ENHANCED CLOUDS...AND THIS HEADING TOWARD THE FA. ANY BREAKS IN THE CLOUD COVER SHOULD ALLOW TEMPS TO FALL RATHER QUICKLY ESPECIALLY OVER THE NRN FA WHERE BOUNDARY LAYER DRIEST. PER RUC DATA...WILL DROP TEMPERATURES SLIGHTLY OVER THE FAR NE ZONES WHERE DEWPOINTS LOWEST. WILL ALSO REWORD TEMPERATURE FORECAST OVER THE SOUTHEAST WHERE HIGHER RH/S AND CLOUD COVER TO STAY LONGEST. WILL WAIT UNTIL NEW MODEL RUNS IN BEFORE SENDING UPDATE TO WINTER STORM WATCH. .FGF...WINTER STORM WATCH LATE TUESDAY NIGHT AND WEDNESDAY ALONG AND NORTH OF COOPERSTOWN-MAYVILLE TO PARK RAPIDS LINE. RJT SOROKA nd AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 935 PM CST MON MAR 13 2000 FORECAST BASICALLY ON TRACK...BUT HAVE UPDATED FOR WINDS...WHICH HAVE DROPPED OFF TO LGT/VRBL ACROSS MOST OF ABR CWA. RUC SFC WINDS SUPPORT ADJUSTING WINDS DOWN A BIT AS WELL. LEFT IN PTLY CLDY ACROSS AREA TONIGHT...BUT WILL HAVE TO WATCH BKN-OVC MID CLOUD AREA OVER E. MT AT THIS TIME...ASSOC WITH 7H/85H WAA...WHICH RUC BRINGS INTO WESTERN CWA LATE TONIGHT. BELIEVE IT WILL HOLD OFF TILL MORNING FCST PKG IS OUT...AND HAVE ONLY MADE MINOR ADJUSTMENTS TO SKY CONDITION WORDING. .ABR...NONE LORENS sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 930 PM EST MON MAR 13 2000 SATELLITE SHOWS THIN HIGH CLOUDS STREAMING TOWARDS CWA DOWNSTREAM FROM VORT MAX TRANSLATING E ACROSS FAR SRN CA. THIS MAY REDUCE RADIATIONAL COOLING OVERNIGHT SOMEWHAT...BUT AM NOT INCLINED TO RAISE FORECAST MINIMA AT THIS POINT. DRY LOCAL AND UPSTREAM SOUNDINGS THIS EVENING APPEAR TO BE SUPPORTIVE OF DECENT RADIATIONAL COOLING OVERALL. SURFACE DEWPOINTS SLIGHTLY ABOVE FORECAST LOWS... BUT EXPECT DEWPOINTS TO LOWER OVERNIGHT AS SOME BOUNDARY LAYER MOISTURE IS REMOVED BY CONDENSATION WHILE TEMPERATURES FALL. MARINE: CURRENT FORECASTS LOOK ON TRACK PER CURRENT OBSERVATIONS AND 14/01Z RUC GUIDANCE. INPUT IS ALWAYS WELCOME. .TLH... AL...NONE. GA...NONE. FL...FIRE WEATHER WATCH TUESDAY AFTERNOON FOR FLORIDA INLAND COUNTIES. TJT fl EAST CENTRAL FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 815 PM EST MON MAR 13 2000 JET CI ASSOCIATED WITH A WEAK MID AND UPPER LEVEL IMPULSE SHUD CONTINUE TO SHIFT S AS IMPULSE PROGGED IN RUC/MES0-ETA MOVES INTO THE ATLC. SOME ADDTNL CI BLOWING OFF CONVECTION OVER THE SERN GULF AND YUCATAN HAS MOVED INTO SRN HALF OF AREA BUT THIS TOO SHOULD TEND TO THIN OUT OVER THE NEXT FEW HOURS. FCST HANDLES THIS CLOUD SEQUENCE WELL AND THE CLEARING SKIES WILL ALLOW TEMPS TO FALL TO FCST VALUES AND BELOW GUIDANCE IN THE DRY AIRMASS. MARINE...WEAKNESS IN PRESS FIELD CONTINUES TO KEEP WNDS RELATIVELY LIGHT OVER S HALF OF AREA. MAY PUSH WND SPEEDS DOWN S HALF IF TREND CONTINUES. .MLB...NONE. BLOTTMAN fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 215 PM CST MON MAR 13 2000 ...CURRENT OVERVIEW... 12Z UA ANALYS SHOWS DEPARTING STORM SYSTEM OVER NEW ENGLAND AND SYSTEM APPROACHING PACIFIC NORTHWEST...WHICH WILL BE OUR NEXT SIGNIFICANT WEATHER MAKER FOR MIDWEEK. ASIDE FROM THESE TWO SYSTEMS...RATHER BENIGN PATTERN ACROSS CONUS WITH ONLY A FEW WEAK WAVES TRAVERSING MID PORTION OF COUNTRY IN WEST/NORTHWESTERLY UPPER FLOW. LATEST SFC/MSAS ANALYS SHOWS LOW PRESSURE OVER LAKE MICHIGAN WITH TRAILING WINDSHIFT/TROF EXITING EAST OF CWA. SFC HIGH CENTERED OVER EASTERN KANSAS WITH RIDGE AXIS EXTENDING NORTH INTO WESTERN IOWA. VISIBLE SATELLITE SHOWS CLOUDS WORKING EAST AND THINNING WITH BACK EDGE THRU CENTRAL IOWA...AHEAD OF SFC RIDGE AXIS. MAIN CONCERNS ARE WITH CLOUDS AND TEMPS THRU 48 HRS WITH PCPN CHCS/TYPE OF CONCERN LATE TONIGHT INTO TUESDAY AHEAD OF NEXT WAVE... THEN PCPN WITH NEXT SYSTEM FOR MIDWEEK. ...SHORT TERM... LATEST RUC IN AGREEMENT WITH BIG THREE IN SHOWING DRYING/SUBSIDENCE TO WORK ACROSS CWA THIS EVENING AS SFC RIDGE AXIS BUILDS IN. SATELLITE TRENDS BACK THIS UP AND WILL FOLLOW SUIT WITH DECREASING CLOUDS THIS EVENING. VISIBLE SATELLITE SHOWS MID LEVEL CLOUDS EXPANDING OVER NEBRASKA WITH RADAR MOSAIC INDICATING SOME ECHOES... THOUGH CHECK OF SFC OBS REVEAL LITTLE REACHING THE GROUND. MODEL RELH PROGS SHOW SOME LOW/MID LEVEL MOISTURE WORKING BACK INTO THE AREA OVERNIGHT SO WILL GO WITH PTCLDY WORDING. MODELS DEPICT ELONGATED RIBBON OF VORTICITY FROM NORTHERN ROCKIES INTO MIDDLE MISSISSIPPI VALLEY TONIGHT THRU TUESDAY WITH MAIN WAVE OF CONCERN...NOW OVER WYOMING...TO PASS MAINLY SOUTH OF CWA ON TUESDAY AS MAIN BAROCLINIC ZONE SETS UP TO OUR SOUTH (NEBRASKA THRU MISSOURI). ALL MODELS SLIGHTLY SLOWER/WEAKER WITH WAVE THAN PREVIOUS RUNS. MODELS SHOWING WEAK LIFT DEVELOPING OVER CWA BETWEEN 06Z-12Z TUESDAY WITH CONDENSATION PRESSURE DEFICITS LOWERING TO AOB 50 MB BY 12Z MAINLY ALONG AND WEST OF RIVER. BULK OF LIFT THOUGH TO SWING ACROSS SOUTHERN ZONES INTO MISSOURI AND CENTRAL/ SOUTHERN ILLINOIS DURING DAY SO WILL PLACE HIGHEST POPS ACROSS SOUTHERN TIER...THOUGH AMOUNTS SHOULD BE FAIRLY LIGHT WITH AVN WETTEST SHOWING .05 TO .10 INCH SOUTHERN HALF OF CWA BETWEEN 12Z-18Z TUES. PCPN TYPE TRICKY WITH MODELS DIVERGING ON STRENGTH OF WARM AIR ADVECTION AHEAD OF SYSTEM. NGM IS VERY AGRESSIVE WARMING H85 TEMPS TO ABOVE 2 C ACROSS SOUTHERN PORTIONS OF CWA BY 12Z WHILE AVN/ETA NOT AS AGRESSIVE KEEPING 0 C ISOTHERM SOUTH OF QUAD CITIES. ALL MODELS CONTINUE WITH WARM AIR ADVECTION DURING DAY TUESDAY SO ANY LIGHT FROZEN PCPN SHOULD QUICKLY CHANGE TO LIQUID. LOW LEVEL THERMAL PROFILE CRUCIAL. 1000-850 THICKNESS FROM NGM AND AVN INDICATE MAINLY RAIN WITH ETA SHOWING POTENTIAL FOR SOME LIGHT FREEZING RAIN OR LIGHT SNOW/FLURRIES IN MORNING NORTH OF CEDAR RAPIDS TO QUAD CITIES. FEEL NGM TOO AGRESSIVE WITH WARM AIR AND ETA A TAD COOL GIVEN DEVELOPMENT OF LOW LEVEL SOUTHWESTERLY FLOW. WITH THAT IN MIND FAVORING AVN THERMAL FIELDS WHICH SUGGESTS MAINLY A COLD RAIN AFFECTING AREAS GENERALLY ALONG AND SOUTH OF I-80 WITH MAINLY TRACE AMOUNTS ACROSS THE NORTH WITH PERHAPS SOME WET FLAKES/SPRINKLES. LOW TEMP FCST ALSO TRICKY TONIGHT WITH CLEARING THIS EVENING AND CLOUDS ASSOCIATED WITH WARM AIR ADVECTION OVERNIGHT. BELIEVE MOST AREAS WILL SEE MIN TEMPS THIS EVENING INTO THE EARLY OVERNIGHT BEFORE STEADYING OUT AND LEANING TOWARD WARMER FAN GUIDANCE. ...LONG TERM... ROLLER COASTER RIDE ON TEMPS. SYSTEM TO SWEEP ACROSS AREA DURING FIRST HALF OF TUESDAY FOLLOWED BY SUBSIDENCE AND PARTIAL CLEARING MAINLY WEST OF RIVER DURING AFTERNOON. MODELS DIFFER ON HANDLING OF ASSOCIATED SFC FRONT WITH NGM AGRESSIVE IN BRINGING IT THRU DURING DAY WHILE AVN/ETA HOLD IT TO OUR WEST AND WASH IT OUT LATE DAY/EVENING AS RETURN FLOW DEVELOPS THRU THE PLAINS AHEAD OF NEXT SYSTEM ORGANIZING OVER THE ROCKIES. AVN A TAD QUICKER WITH NEXT SYSTEM THAN ETA/NGM AND GENERALLY FOLLOWED GIVEN DECENT RUN TO RUN CONTINUITY. CYCLOGENESIS TO TAKE PLACE TUESDAY NIGHT OVER NORTHERN PLAINS WITH SFC LOW DEEPENING AND MOVING E/SE ACROSS MINNESOTA ON WEDNESDAY AND INTO GREAT LAKES WEDNESDAY NIGHT. THIS WILL DRAG AN ARCTIC FRONT INTO THE AREA DURING AFTERNOON...EXITING DURING THE EVENING. WINDS FAIRLY BREEZY AHEAD OF FRONT LATE TUESDAY NIGHT INTO WEDNESDAY HELPING TO BRING MOISTURE AND WARM AIR NORTHWARD. WILL STICK WITH WARMER GUIDANCE FOR MAXES WEDNESDAY THOUGH WILL BE TRICKY WITH CLOUDS/PCPN. BULK OF PCPN TO OCCUR IN THE AFTERNOON/EARLY EVENING WITH THUNDER A POSSIBILITY GIVEN TIMING AND DYNAMICS...THOUGH PROGGED INSTABILITY NOT GREAT. FOR NOW WILL THROW IN MENTION OF THUNDER IN SOUTHERN ZONES. TURNING SHARPLY COLDER AND WINDY WEDNESDAY NIGHT AS H85 TEMPS AND THICKNESSES CRASH. ...EXTENDED(THU-SAT)... UPPER TROF SWINGS THRU CWA THURSDAY WITH MRF SHOWING CANADIAN HIGH BUILDING SOUTH ACROSS THE MIDWEST DURING AFTERNOON. LINGERING MOISTURE COMBINED WITH COLD AIR AND APPROACHING TROF SUPPORT CHC OF MORNING LIGHT SNOW MAINLY ALONG AND EAST OF RIVER FOLLOWED BY CLEARING. HIGH PRESSURE SFC/ALOFT SWEEP ACROSS AREA FRIDAY RESULTING IN PLENTY OF SUNSHINE. NEXT SYSTEM DEVELOPS OVER ROCKIES FRIDAY WITH MRF BRINGING IT THRU LATE FRIDAY NIGHT AND SATURDAY. THICKNESS FIELDS AND FORECAST SOUNDINGS SUPPORT LIGHT SNOW INITIALLY WITH A MIX OR PERHAPS CHANGEOVER TO RAIN INDICATED DURING AFTERNOON AS MRF AGGRESSIVE WARMING LOW LEVEL THERMAL FIELDS. MRF SHOWING DECENT WARMUP LATE IN WEEKEND THRU MIDDLE OF NEXT WEEK. COORD WITH KDMX...THANX .DVN... IA...NONE. IL...NONE. MO...NONE. M^2 il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 915 PM MON MAR 13 2000 SATELLITE IMAGERY SHOWS AN AREA OF MID TO HIGH LEVEL CLOUDINESS ASSOCIATED WITH A FAST MOVING SHORT WAVE PASSING BY TO OUR NORTH ACROSS THE MID ATLANTIC STATES. THE 18Z ETA AND RUC ARE CONSISTENT IN KEEPING THIS FEATURE AND ITS CLOUDS WELL TO OUR NORTH OVERNIGHT. WITH THAT IN MIND...THE CURRENT SET OF ZONES LOOKS FINE. THE ONLY CONCERN IS LOW TEMP FORECAST BEING AS MUCH AS A CATEGORY OR SO BELOW GUIDANCE VALUES...BUT WITH GOOD RADIATIONAL COOLING EXPECTED OVERNITE...WILL NOT CHANGE ANYTHING. .GSP...NONE. MOORE sc AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE DES MOINES IA 950 AM CST TUE MAR 14 2000 SHORT TERM... UPDATE TO ZONES HAS BEEN SENT TO REMOVE RAINFALL AND TO MAKE SLIGHT ADJUSTMENTS TO CLOUDS AND TEMPS. WAA GENERATED SHRA HAVE CLEARED THE CWA. RAINFALL IS ALSO REMAINING JUST TO THE S OF THE BORDER IN MO. SATELLITE TRENDS INDICATE A CLEARING TREND LIKELY IN THE SW AND SC ZONES BY EARLY AFTERNOON. MORNING SOUNDINGS INDICATED THAT TEMP FORECASTS ONLY NEEDED SLIGHT MODIFICATIONS. RUC FORECASTS ALSO SHOW 55-60 MOST OF CENTRAL AND SW. .DSM...NONE KULA ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 915 AM EST TUE MAR 14 2000 PATCH OF CI MOVING OVHD ATTM...W/ MORE HIGH CLOUDINESS POISED TO THE W IN ZONAL FLOW ALOFT. CI IS THIN AND MOSTLY SUNNY SKIES WILL CONTINUE TO BE THE RULE. WEAK CYCLONIC SWIRL SEEN IN THE LOW CLOUDS OFF THE SC COAST. RUC SFC WIND FIELD INITIALIZES THIS FEATURE WELL ...BUT APPEARS TO LOSE IT TOO QUICKLY. IF ANYTHING...ONLY EXPECTING THIS FEATURE TO DELAY VEERING WIND DIR (ESP IN THE CWF)... AND THE LOW CLOUDS REMAINING OFFSHORE. LOW-LEVEL THICKNESS SCHEME AND LAMP PROJECTIONS SUPPORT FCST TEMPS FOR TODAY...REST OF TODAY/S FCST LOOKS GOOD TOO. CWF: W/ WEAK LOW OFF THE COAST WILL PROBABLY HAVE TO INITIALIZE W/ A N WIND DIR. ENOUGH OF A PGF TO KEEP WINDS AT 15 KT THIS AFTERNOON. .ILM...NONE. PFAFF nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 230 PM CST TUE MAR 14 2000 ...CURRENT OVERVIEW... RADAR MOSAIC SHOWING AREA OF -RA ACROSS SOUTHERN IOWA...MISSOURI AND CENTRAL ILLINOIS. KDVN WSR-88D ALSO SHOWING EXPANSIVE ECHOES NORTH OF I-80 WITH ALL PCPN LIFTING E/NE FAIRLY QUICKLY. PCPN DEVELOPING IN RESPONSE TO SHORTWAVE OVER NORTHWEST MISSOURI...AND HAVING TOUGH TIME REACHING GROUND OVER ALL BUT FAR SOUTH WITH 12Z KDVN SOUNDING SHOWING DRY LOW LEVELS. WATERLOO(KALO) MANAGED TO PICK UP .03 WITH DUBUQUE(KDBQ) RECENTLY REPORTING -RA...SO AT BEST JUST A FEW SPRINKLES OR BRIEF -SHRA. LATEST SFC/MSAS ANALYS SHOWS ARCTIC BOUNDARY STRUNG OUT WELL TO THE NORTH FROM THE DAKOTAS INTO NORTHERN WISCONSIN. WEAK TROF NOTED VICINITY OF MASON CITY (KMCW) TO DENISON (KDNS). FURTHER SOUTH BUBBLE HIGH ANALYZED WEST OF COLUMBIA MISSOURI (KCOU) WITH DEVELOPING WARM FRONT EXTENDING FROM LOW PRESSURE OVER WEST TEXAS THRU NORTHERN OKLAHOMA INTO SOUTHERN MISSOURI. INTERACTION OF BUBBLE HIGH AND WARM FRONT HAS LEAD TO SOME INTENSIFICATION OF TSTMS OVER SOUTHWEST MISSOURI. LOW LEVEL SOUTHWEST FLOW/COMPRESSIONAL HEATING AHEAD OF WEAK SFC TROF HAS BOOSTED TEMPS WELL INTO THE 50S ACROSS CWA WITH A FEW AREAS HITTING 60 DEGS CENTRAL/SOUTHERN ZONES. BRIEF SHOWER KNOCKED DUBUQUE (KDBQ) BACK TO 47 DEGS LAST HOUR. MAIN CONCERNS ARE WITH PCPN CHCS WED/WED NGT ALONG WITH CLOUDS AND TEMPS THROUGHOUT. ...SHORT TERM (0-24 HRS)... MODELS INITIALIZED REASONABLY WELL WITH SHORTWAVE OVER NORTHWEST MISSOURI AND MOVE IT EAST OF REGION BY 06Z. MAIN FORCING/DYNAMICS TO AFFECT SOUTHERN AND FAR EASTERN AREAS. MAY GO WITH LOW POPS THESE AREAS FOR THIS EVENING...THOUGH LATEST RADAR TRENDS WILL DICTATE. VISIBLE SATELLITE SHOWS CLEARING INTO NORTHWEST/WESTERN IOWA. MODELS NOT DOING WELL WITH CLOUD TRENDS...THOUGH LATEST RUC APPEARS TO HAVE BEST HANDLE AND WILL GENERALLY FOLLOW FOR TONIGHT. CU FIELD DEVELOPING ON WESTERN EDGE OF CLOUD SHIELD FROM CENTRAL INTO SOUTHWEST IOWA SHOULD DISSIPATE WITH LOSS OF HEATING...LEAVING BEHIND LOW/MID CLOUDS IN ASSOCIATION WITH SHORTWAVE. VISIBLE SATELLITE ALSO SHOWS LARGE PLUME OF CIRRUS STREAMING THRU PLAINS AHEAD OF NEXT SYSTEM. RUC KEEPS SOME LOW/MID CLOUDS AROUND TONIGHT WITH WARM AIR ADVECTION DEVELOPING BEHIND WAVE...AND ALSO SHOWS CIRRUS THICKENING OVERNIGHT. THAT BEING SAID PTCLDY/MOCLDY SHOULD SUFFICE. LOW TEMPS A TOUGH CALL. WITH ENOUGH MIXING AND DEWPTS SLOWLY CLIMBING DURING NIGHT...WILL CERTAINLY NOT UNDERCUT GUIDANCE AND MAY GO A FEW DEGS WARMER. COULD SEE PATCHY FOG AGAIN TONIGHT WITH WARM AIR ADVECTION... HOWEVER ENOUGH MIXING SHOULD KEEP IT IN CHECK. ...LONG TERM (24-48 HRS)... UPPER PATTERN TO TRANSITION FROM NEARLY ZONAL TO HIGHLY AMPLIFIED FLOW BY END OF PD. MODELS IN REASONABLE AGREEMENT ON DROPPING ARCTIC BOUNDARY...NOW OVER DAKOTAS/CENTRAL MINNESOTA/NORTHERN WISCONSIN... SLOWLY SOUTHWARD INTO SOUTHERN MINNESOTA/CENTRAL WISCONSIN BY 12Z WED ...FASTER THAN PREVIOUS RUNS. PRE-FRONTAL TROF/WIND SHIFT TO EXTEND ACROSS WESTERN IOWA DURING SAME TIMEFRAME. MODELS EXHIBITING TIMING DIFFERENCES ON INITIAL TROF/WIND SHIFT WHICH WILL HAVE BIG IMPACT ON MOISTURE AVAILABILTY AND PCPN CHCS. NGM QUICKEST BRINGING SFC TROF INTO CENTRAL IOWA BY 12Z...ETA SLOWEST AND AVN...AS USUAL...MIDDLE OF ROAD. AVN SHOWING DECENT RUN TO RUN CONTINUITY AND FAVOR BLEND OF SLOWER AVN/ETA WITH MAIN VORT DIGGING THRU ROCKIES AND TAKING A MORE SHEARED LOOK ACROSS PLAINS/UPPER MIDWEST. NGM BEING QUICKEST ALSO DRIEST WITH DYNAMICS OUTRUNNING MOISTURE. ETA/AVN VERIFYING MUCH BETTER AT 18Z WITH REGARDS TO LOW LEVEL MOISTURE OVER SOUTHERN PLAINS. THEIR SLOWER SOLUTIONS WILL ALLOW MORE TIME FOR THIS MOISTURE TO MEET UP WITH DYNAMICS GIVING US BETTER CHC FOR PCPN. BOTH ETA/AVN SHOW SFC DEWPTS CLIMBING INTO THE U40S/L50S DURING EARLY AFTERNOON WITH GRADIENT NOSING INTO FAR WESTERN ZONES. WILL PLACE HIGHEST POPS EAST OF RIVER...AND LOWEST POPS OVER WESTERN ZONES WITH BULK OF PCPN STARTING LATE MORNING INTO AFTERNOON FROM WEST TO EAST. TSTMS POSSIBLE WITH AVN SHOWING LI/S APPROACHING ZERO AS FAR NORTH AS QUAD CITIES. LIMITED INSTABILITY (CAPES BETWEEN 100-200 J/KG AND LI/S NEAR ZERO) WILL SQUELCH ANY POTENTIAL FOR STRONG TO SEVERE TSTMS EVEN GIVEN TIME OF FROPA (AFTN/EVE) ARCTIC FRONT TO SWEEP ACROSS REGION WEDNESDAY NIGHT. COULD SEE BREAK IN PCPN DURING EVENING BEFORE MORE LIGHT PCPN ACCOMPANIES ARCTIC FRONT AND SHEARED UPPER VORT. INITIALLY EXPECT LIGHT RAIN...BUT AS H85 TEMPS AND THICKNESSES CRASH COULD SEE SOME WET SNOWFLAKES MIXED IN BEFORE ENDING EARLY THURSDAY MORNING. AVN HINTING AT ANOTHER WAVE TO DROP SOUTH ACROSS AREA...AND GIVEN CYCLONIC FLOW AND LINGERING MOISTURE COULD SEE SCATTERED FLURRIES OR PERHAPS A FEW SNOW SHOWERS. MAX TEMPS WEDNESDAY WILL BE TRICKY. SOUTHWEST FLOW AHEAD OF TROF YIELDS GOOD COMPRESSIONAL HEATING...THOUGH CLOUDS AND ANY PCPN SHOULD NEGATE SOME OF THIS. LEANING TOWARD GOING SLIGHTLY ABOVE GUIDANCE. ANY SUNSHINE...AND TEMPS COULD SOAR...SO BEWARE POTENTIAL BUST. GUIDANCE IN GENERAL AGREEMENT IN LATER PERIODS AND WON/T STRAY TOO FAR BUT WILL TWEEK. ...EXTENDED (FRI-SUN)... CANADIAN HIGH PRESSURE BUILDS SOUTH ACROSS AREA FRIDAY RESULTING IN DRY BUT COLD CONDITIONS. MRF SHIFTS CANADIAN HIGH EAST ON SATURDAY WITH RETURN FLOW COMMENCING AHEAD OF DEVELOPING SYSTEM OVER PLAINS. MRF ABOUT 12-18 HRS SLOWER WITH SYSTEM THAN PREVIOUS RUN AND STILL MIGHT BE TOO QUICK TO REMOVE CANADIAN HIGH. UPPER TROF WORKS INTO AREA SUNDAY WITH MRF DEVELOPING CLOSED LOW OVER LOWER MISSISSIPPI VALLEY AND LIFTING E/NE INTO OHIO VALLEY EARLY NEXT WEEK. WILL DELAY PCPN CHCS UNTIL SUNDAY. .DVN... IA...NONE. IL...NONE. MO...NONE. M^2 il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 920 AM CST TUE MAR 14 2000 EARLY INDICATIONS ARE THAT ETA IS STILL THE SLIGHTLY BETTER CHOICE ATTM. BOTH RUC AND MSAS DEPICT MINOR FEATURES QUITE WELL, SUCH AS THE SMALL DISTURBANCE PASSING BY INL AND THE POSITION AND STRENGTH OF THE SFC LOW IN MONTANA. NONE OF THE MODELS HAVE A REAL LOCK ON THIS THING YET, BUT PERHAPS THE 12Z SUITE OF MODELS WILL BE ABLE TO FIND A CLOSER CONSENSUS. NO CHANGES TO FORECAST PACKAGE PLANNED ATTM. .DLH...NONE. CS mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 252 PM CST TUE MAR 14 2000 FCST CONCERNS ARE TEMPS AND TIMING PCPN CHCS THRU WED. CLDS AND SPRINKLES/--SHRA FORMING IN MOIST CONVERG ZONE OVR CWA... BETWEEN SUBTLE SFC BNDRY LAYING ACROSS CNTRL WI AND WK DISTURBANCE PASSING TO OUR SOUTH THRU CNTRL IL. PCPN ASSOC WITH LFQ OF UPR JET SPREADING ACROSS ARROWHD OF MN. SFC LO DVLPG IN WRN DKTS WL BE MAIN WX MAKER FOR WI THE NEXT 24-36 HRS. NCEP MDLS IN GUD AGREEMENT WITH UPR LVLS...TAKING FIRST JET MAX ACRS NRN WI/UP ERLY TNT...WITH ANOTHER E/W ORIENTED SPD MAX FAST ON IT/S HEELS. CPLG OF JETS OVR THE FAR NORTH COULD GIVE THEM SOME HVY SNOW. RRQ WILL BE AFFECTING OUR CWA. DIFFERENCES IN SPEED...STRENGTH AND TIMING OF H5 VORT AND H5 TROF. AVN MORE COMPACT AT FIRST...BUT COMES IN LINE WITH ETA AND NGM AND A MORE SHEARED LOOK BY 36 HRS. H5 WAVE HANGS UP UNTIL ENERGY ROUNDS BASE OF TROF THRU KS THU AM. NGM/AVN BRING TROF AXIS OVR CWA...WITH ETA KPG IT BACK TO THE NW. H7 RH AND UVV PANELS INDICATE BEST MOISTURE AND LIFT SE OF CWA BY 00Z THU. NGM/AVN HAVE BETTER HNDL ON SFC LO AT 18Z...WITH 18Z RUC FOLLOWING NGM SPEED. LO CROSSES ST TMRW MORNING...AND INTO LWR MI BY 00Z. CHC POPS TNT AS WAA KICKS IN...LIKELY FOR TMRW. ALL LIQUID AS SNDGS AND GUIDNC KEEP TEMPS ABV FREEZING TNT IN LOWEST 3K FT IN SRLY FLO AHD OF LO. TEMPS WL STAY UP WITH H8 CAA NOT STARTING UNTIL AFTER 18Z ACRS CWA. LI/S APPCHG ZERO AND SOME CAPE AROUND 18Z ON BUFKIT SNDGS MEAN CHC OF SOME EMBEDDED THUNDER. WONT MENTION SN..AS PCPN ENDING BEFORE COLDEST AIR WRKS IN. WL TEND TWD HIER FWC TEMPS VS FAN FOR ERLY HI/S WED...THO 3 HRLY VALUES LOOK BETTER THAN 12 HR TEMPS GIVEN CLDS AND PCPN. .UWNMS...SIMILAR TO NCEP MDLS BUT BRING SFC LO FARTHER SOUTH.THUS 2M TEMPS ARE COOLER. THANKS TO GRB FOR COORD .MKX...NONE. 0...0...0...0 $$ REM wi