INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA 305 PM PST FRI FEB 14 2003 A VERY PLEASANT...AND MUCH MORE TRANQUIL...DAY WAS CONTINUING TO UNFOLD ACROSS THE SAN JOAQUIN VALLEY THIS AFTERNOON. WINDS REMAINED LIGHT NORTHWESTERLY AS THE MERCURY CLIMBED INTO THE 60S AT MOST VALLEY SITES. THE RESPITE FROM THE ACTIVE WEATHER WILL INDEED BE BRIEF...AS UPPER LEVEL MOISTURE IS ALREADY INVADING FROM THE WEST IN ADVANCE OF THE NEXT UPPER LEVEL TROUGH OF LOW PRESSURE TAKING SHAPE ACROSS THE EASTERN PACIFIC. THESE HIGH CLOUDS...ALONG WITH A DEVELOPING LIGHT SOUTHERLY FLOW...WILL KEEP TEMPERATURES FAIRLY MILD OVERNIGHT. SOME PATCHY FOG WILL LIKELY FORM IN THE VALLEY AS THE GROUND AND BOUNDARY LAYER REMAIN DAMP COURTESY OF THE RECENT RAINS AND MID LAYERS STILL SHOW SOME REMNANT SUBSIDENCE OVERNIGHT PER RUC PROGS. DEEPER MOISTURE WILL ARRIVE SATURDAY...BUT HAVE TRIMMED BACK AFTERNOON POPS TO SLIGHT CATEGORY FOR EXTREME NORTHERN VALLEY SXNS AS WELL AS THE NORTHERN SIERRA THINKING THAT A BETTER BLEND OF THE ETA/GFS...RATHER THAN SOLELY THE FASTER GFS...IS MORE REALISTIC. SATURDAY NIGHT AND EARLY SUNDAY SHOULD BRING THE MAIN PRECIPITATION EVENT. WITH SW H7 FLOW ON THE ORDER OF 30-40 KTS...THE WINDWARD COAST RANGES SHOULD SQUEEZE OUT MUCH OF THE MOISTURE BEFORE IT HAS A CHANCE TO REACH THE VALLEY FLOOR. THE SIERRA MOUNTAINS...HOWEVER...LOOK TO BE A DIFFERENT STORY AS THE OROGRAPHICS SHOULD BE QUITE FAVORABLE TO INDUCE SIGNIFICANT PRECIPITATION. MESOETA TABULAR QPF/S FOR YOSEMITE AND GIANT FOREST HAVE CREPT UPWARD BETWEEN THE 18Z AND 12Z RUNS...AND THE 1.5 TO 2 INCHES OF LIQUID EQUIVALENT SHOULD BE GOOD ENOUGH TO DEPOSIT BETWEEN ONE AND TWO FEET OF SNOW BY SUNDAY AFTERNOON FOR ELEVATIONS ABOVE 5000 FEET MSL. OTHERWISE...EVENT SHOULD WIND DOWN SUNDAY AFTERNOON FOR THE VALLEY BUT MAY LINGER INTO THE EARLY EVENING HOURS ALONG THE SPINE OF THE SIERRA. MONDAY LOOKS TO BE GENERALLY DRY...ALTHOUGH DID DECIDE TO THROW IN SOME SLIGHT CHANCE POPS FOR ZONE 96 AS THE NEXT TROUGH PUSHING IN FROM THE WEST MAY HAVE DEEP ENOUGH MID LEVEL MOISTURE TO DROP A LIGHT SHOWER. BURGER FOR THE TIME FRAME TUESDAY THROUGH THURSDAY...HAVE LOW CONFIDENCE IN EXTENDED FORECAST SINCE MEDIUM RANGE MODELS HAVE BEEN SHOWING POOR RUN TO RUN CONSISTENCY AND LARGE TIMING DIFFERENCES. WILL CONTINUE TO MENTION LOW CHANCES OF PRECIPITATION TUESDAY WITH MOST PROGS ADVERTISING AN UPPER LEVEL SHORTWAVE MOVING THROUGH CA TUESDAY. DRIEST DAY OF THE EXTENDED COULD BE WEDNESDAY AS SHORT WAVE RIDGING BUILDS OVER THE AREA. AT THIS TIME WILL MENTION LOW POPS ACROSS THE CWFA STARTING WEDNESDAY NIGHT AND CONTINUE THROUGH FRIDAY WITH MODELS INDICATING A DEEPER CUTOFF LOW MOVING INTO THE EASTERN PACIFIC THURSDAY. MV .HNX...WINTER STORM WATCH FOR THE SIERRA NEVADA MOUNTAINS...NORTH OF KERN COUNTY...SATURDAY NIGHT AND SUNDAY. $$ ca FLORIDA KEYS AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE KEY WEST FL 1030 AM EST FRI FEB 14 2003 BASED ON NEW INCOMING MODEL OUTPUT...SMALL CRAFT ADVISORY WILL BE CHANGED TO "EXERCISE CAUTION" FOR ATLANTIC-SIDE WATERS. CURRENTLY... HIGH PRESSURE CENTER IS NOW OFF GA/NE FLORIDA COAST WITH RIDGING SEEMINGLY GETTING SET UP EAST AND WEST ALONG LAT 30-32N OR THEREABOUTS. WINDS OVER KEYS ISLAND SITES HAVE BEEN GUSTING IN THE WARMER EAST WINDS AT OCEAN REEF THIS MORNING...WERE LIGHTER AT MID AND LOWER KEYS UNTIL THE PAST FEW MINUTES. KEY WEST SAW THE EAST WINDS PUNCH IN...WITH SOME GUSTINESS...AND A TEMP. AND DEWPOINT RISE. STILL...C-MAN SITES ON THE REEF AND BAY HAVE BEEN ERRATIC WITH WIND SPEEDS...RUNNING ONLY 13 KT AT SAND KEY AT 9 AM...BUT 18 KT FOR LONG KEY AND SOMBRERO KEY. CU AND SC CLOUDS ARE MOVING W OFF THE STRAITS AND OVER THE KEYS NOW...SCATTERED TO LOCALLY BROKEN IN COVERAGE. DON'T HAVE ANY SHIP OBS OUT IN THE STRAITS THIS MORNING. SATELLITE QUIKSCAT WINDS FROM 43O AM THIS MORNING ONLY HAD A SWATH OVER STRAITS EAST OF 80W...BUT IT DID SHOW 20 KT EAST WINDS. THIS AFTERNOON... FOR 1030 AM COASTAL WATERS FORECAST ISSUANCE... 06Z MESOETA OUTPUT AND ALSO NEW INCOMING 00-12 HR FORECAST FOR 12Z MESOETA...BOTH INDICATE WINDS DROPPING TO 15 KT THIS AFTERNOON OVER NORTH SECTIONS OF COASTAL AREAS AND NEAR KEYS ISLANDS...STAYING NEAR 20 KT IN OUTER STRAITS...SIMILAR TO PAST COUPLE OF DAYS. RUC HAS BEEN LOOKING ERRATIC WITH WINDS LATELY (MAINLY TOO LOW WITH SPEEDS)...BUT CURRENT RUC SHOWS WINDS INCREASING AGAIN TO 20 KT... THUS CONFUSING THINGS. KEY WEST DOPPLER RADAR WINDS AT 1 THSD FT HAVE ACTUALLY COME DOWN NEARER TO 15 KT...COMPARED TO 20 KT A FEW HOURS AGO. WILL LOOK AT LAST MINUTE C-MAN OBS AND SOLICIT VHF REPORTS...BEFORE SENDING 1030 AM COASTAL WATERS FORECAST. MIGHT ADJUST ATLANTIC WINDS TO 15-20 KT WITH "EXERCISE CAUTION". PUBLIC ZONES WILL NOT BE UPDATED. ALL IS WELL. .EYW...NONE. C.B. fl FLORIDA KEYS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KEY WEST FL 1000 AM EST FRI FEB 14 2003 CURRENTLY... HIGH PRESSURE CENTER IS NOW OFF GA/NE FLORIDA COAST WITH RIDGING SEEMINGLY GETTING SET UP EAST AND WEST ALONG LAT 30-32N OR THEREABOUTS. WINDS OVER KEYS ISLAND SITES HAVE BEEN GUSTING IN THE WARMER EAST WINDS AT OCEAN REEF THIS MORNING...WERE LIGHTER AT MID AND LOWER KEYS UNTIL THE PAST FEW MINUTES. KEY WEST SAW THE EAST WINDS PUNCH IN...WITH SOME GUSTINESS...AND A TEMP. AND DEWPOINT RISE. STILL...C-MAN SITES ON THE REEF AND BAY HAVE BEEN ERRATIC WITH WIND SPEEDS...RUNNING ONLY 13 KT AT SAND KEY AT 9 AM...BUT 18 KT FOR LONG KEY AND SOMBRERO KEY. CU AND SC CLOUDS ARE MOVING W OFF THE STRAITS AND OVER THE KEYS NOW...SCATTERED TO LOCALLY BROKEN IN COVERAGE. DON'T HAVE ANY SHIP OBS OUT IN THE STRAITS THIS MORNING. SATELLITE QUIKSCAT WINDS FROM 43O AM THIS MORNING ONLY HAD A SWATH OVER STRAITS EAST OF 80W...BUT IT DID SHOW 20 KT EAST WINDS. THIS AFTERNOON... FOR 1030 AM COASTAL WATERS FORECAST ISSUANCE... 06Z MESOETA OUTPUT AND ALSO NEW INCOMING 00-12 HR FORECAST FOR 12Z MESOETA...BOTH INDICATE WINDS DROPPING TO 15 KT THIS AFTERNOON OVER NORTH SECTIONS OF COASTAL AREAS AND NEAR KEYS ISLANDS...STAYING NEAR 20 KT IN OUTER STRAITS...SIMILAR TO PAST COUPLE OF DAYS. RUC HAS BEEN LOOKING ERRATIC WITH WINDS LATELY (MAINLY TOO LOW WITH SPEEDS)...BUT CURRENT RUC SHOWS WINDS INCREASING AGAIN TO 20 KT... THUS CONFUSING THINGS. KEY WEST DOPPLER RADAR WINDS AT 1 THSD FT HAVE ACTUALLY COME DOWN NEARER TO 15 KT...COMPARED TO 20 KT A FEW HOURS AGO. WILL LOOK AT LAST MINUTE C-MAN OBS AND SOLICIT VHF REPORTS...BEFORE SENDING 1030 AM COASTAL WATERS FORECAST. MIGHT ADJUST ATLANTIC WINDS TO 15-20 KT WITH "EXERCISE CAUTION". PUBLIC ZONES WILL NOT BE UPDATED. ALL IS WELL. .EYW...SMALL CRAFT ADVISORY FOR OCEAN REEF TO 20 NM WEST OF DRY TORTUGAS OUT 60 NM INTO THE STRAITS OF FLORIDA. C.B. fl AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GOODLAND KS 845 PM MST FRI FEB 14 2003 FORECAST AS A WHOLE PRETTY MUCH ON TRACK. HOWEVER...WILL NEED TO MAKE ADJUSTMENTS WITH THE MAJOR ONE BEING PRECIPITATION TYPE. DAY FORECASTER WAS WORRIED ABOUT FREEZING RAIN IN NORTHERN AND EASTERN SECTIONS CAUSING PROBLEMS. LOOKING AT LBF SOUNDING AND CURRENT OBSERVATIONS SHOW SNOW IS GOING ON ALTHOUGH THE SOUNDING IS NOT VERY COLD THROUGH A DEEP LAYER. WOULD THINK SOME SEEDING MAY BE GOING ON FROM ABOVE. RUC SOUNDINGS DOING VERY GOOD...ALTHOUGH THEY ARE A TAD WARM. LOWER LEVELS GET COLDER AS THE NIGHT PROGRESSES WITH ONLY A SHALLOW SATURATED LAYER BELOW 700 MB. THEIR IS A DRY LAYER THAT STARTS NEAR 700 MB. DYNAMICS LOOK WEAK THROUGH THE REST OF THE NIGHT WITH EASTERN SECTIONS GETTING SOME WRAP AROUND. ALSO MODELS INSIST THAT UPSLOPE IS GOING TO BE WEAK AS WELL. SO WILL TAKE OUT FREEZING RAIN...AND JUST SAY SNOW WITH PATCHY FREEZING DRIZZLE. MODELS AND AREA PROFILERS/OBSERVATIONS WOULD ALSO SAY WINDY EAST AND BREEZY WEST...AND WILL WORD THAT WAY. GOING BY RUC SOUNDINGS AND CURRENT OBSERVATIONS...WILL LOWER LOWS EXCEPT FOR EXTREME SOUTH AND SOUTHEAST LOCATIONS. .GLD...NONE. $$ BULLER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 215 PM MST FRI FEB 14 2003 FORECAST CHALLENGES INCLUDE PRECIP TYPE AND CHANCES TONIGHT INTO EARLY TOMORROW AS WELL AS EFFECTS OF CLOUDS ON TEMPERATURES THROUGH THE WEEKEND. 19Z SURFACE MAP ANALYSIS SHOWED A LOW PRESSURE SYSTEM CENTERED OVER SOUTHERN KANSAS WITH A WARM FRONT EXTENDING SOUTHEAST INTO EASTERN OKLAHOMA AND A COLD FRONT WESTWARD INTO SOUTHERN COLORADO. IR AND WATER VAPOR SATELLITE IMAGERY SHOWED A SHORTWAVE ASSOCIATED WITH THE DEEPENING SURFACE LOW MOVING NORTHEAST THROUGH OKLAHOMA INTO EASTERN KANSAS. UPPER TROUGH WAS SPINNING OFF THE WEST COAST. MODELS WERE IN GOOD AGREEMENT OUT THROUGH 36 HOURS WITH SURFACE AND UPPER LEVEL FEATURES. WILL GO WITH A BLEND OF AVN AND ETA MODELS OUT THROUGH DAY 3 SINCE THE ETA IS BEST HANDLING STRENGTH AND POSITION OF SURFACE FEATURES WHILE AVN IS A LITTLE BETTER WITH TEMPERATURES AND MOISTURE. FIRST BIG FORECAST CONCERN LIES WITH TONIGHT INTO EARLY SATURDAY. SURFACE LOW DEEPENING OVER SOUTHERN KANSAS AS IT MOVES NORTHEAST. STRONG 850 MB JET MOVING EASTWARD OVER NORTHERN FORECAST AREA TONIGHT. ABUNDANT LOW LEVEL MOISTURE AND WARM AIR ADVECTION CONTINUES TO BE PULLED NORTHWARD INTO THE LOW OVER CENTRAL AND EASTERN KANSAS INTO NEBRASKA. COLDER AIR TO OUR NORTH IN WYOMING AND NEBRASKA MOVING SLOWLY SOUTHWARD TOWARD FORECAST AREA. AFTER VIEWING SOUNDINGS FROM RUC40 AND MESOETA EXPECT WRAP AROUND MOISTURE TO MOVE OVER MOST OF FORECAST AREA. WILL CARRY LIGHT RAIN MIXING WITH FREEZING RAIN AND SLEET OVER THE MCCOOK NEBRASKA AREA BEFORE CHANGING TO SNOW AFTER MIDNIGHT. ELSEWHERE WILL CARRY CHANCE POPS FOR LIGHT RAIN POSSIBLY MIXING WITH SNOW BEFORE CHANGING TO SNOW AFTER MIDNIGHT. EXPECT PRECIPITATION TO CONTINUE INTO SATURDAY MORNING BEFORE ENDING. AT THIS TIME EXPECT LITTLE OR NO ACCUMULATION EXCEPT FOR THE MCCOOK AND HILL CITY AREAS WHERE UP TO AN INCH IS POSSIBLE. COLDER AIR CONTINUES TO MOVE SOUTHWARD OVERNIGHT. EXPECT TEMPERATURES TO FALL INTO THE MIDDLE 20S LATER IN THE NIGHT. FOR SATURDAY AS SYSTEM MOVES SLOWLY TO THE EAST AWAY FROM THE AREA EXPECT SKIES TO REMAIN MOSTLY CLOUDY. BREEZY NORTH WINDS WILL MAINTAIN COLD AIR ADVECTION ACROSS THE AREA. WILL GO WITH DAYTIME HIGH TEMPERATURES MOSTLY IN THE 30S. FOR SATURDAY NIGHT HIGH PRESSURE BUILDS BACK INTO THE REGION RESULTING IN PARTLY CLOUDY SKIES. WILL GO CLOSE TO GUIDANCE TEMPERATURES IN THE UPPER TEENS TO LOWER 20S. FOR THE PERIOD SUNDAY THROUGH FRIDAY WILL MAKE NO CHANGES TO GOING FORECAST OTHER THAN TO ADD DAY 7 (FRIDAY). MRF AND ECMWF BOTH ADVERTISE ANOTHER STORM SYSTEM TO MOVE INTO THE CENTRAL HIGH PLAINS WEDNESDAY AND THURSDAY OF NEXT WEEK. WILL NEED TO SEE ONE MORE MODEL RUN SINCE POSITION OF SYSTEM IS IN GREAT DISAGREEMENT BETWEEN MRF AND ECMWF. FUTURE SHIFT MAY NEED TO ADD PRECIPITATION CHANCES FOR WEDNESDAY AND THURSDAY. WILL ADD NEXT FRIDAY AS PARTLY CLOUDY WITH DAYTIME TEMPERATURES IN THE 40S AND NIGHT TIME LOW TEMPERATURES IN THE 20S. .GLD...NONE. $$ LAMMERS ks AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GOODLAND KS 707 AM MST FRI FEB 14 2003 CURRENT ANALYSIS AND RADAR TRENDS SHOW PRECIP ON A SLOW INCREASE IN AREA OF 700-500 THTE-E AXIS AND ASSOCIATED MID LEVEL OMEGA MAX. LATEST RUC HAS A GOOD HANDLE ON THE QPF COMPARED TO THE RADAR IMAGERY AND EXTRAPOLATION OF THE QPF FORECASTS FROM IT AND THE ETA SHOW A NORTHEAST TO SOUTHWEST AXIS OF HIGHER PRECIPITATION AMOUNTS. GIVEN A BIT OF CONFIDENCE WILL BUMP POPS UP TO 40 PERCENT FOR THE ABOVE GIVEN AREA AND 30 PERCENT ON THE NORTHERN AND SOUTHERN/SOUTHEASTERN FRINGES OF IT. WILL ALSO KEEP DENSE FOG ADVISORY GOING FOR NOW...EXPECT IT TO ERODE FROM WEST TO EAST AS NORTHWEST WINDS INCREASE BEHIND DEPARTING SURFACE LOW. DDT -----------------------PREVIOUS DISCUSSION--------------------------- FORECAST CHALLENGES INCLUDE TIMING END OF DENSE FOG AND POPS TODAY AND HOW COLD TEMPERATURES WILL BE SATURDAY. THE 08Z SURFACE CHART PLACES AN AREA OF LOW PRESSURE OVER EASTERN COLORADO WHERE WINDS WERE GENERALLY OUT OF THE WEST. THE FOG PRODUCT SHOWING SOME DISSIPATION OVER THE WEST PART OF EASTERN COLORADO. LIC AND AKO WERE NOT REPORTING ANY FOG. WATER VAPOR IMAGERY SHOWS ENERGY FROM THE UPPER LOW MOVING ACROSS COLORADO AND WESTERN KANSAS. DIFFICULT TO FIND CENTER OF CIRCULATION BUT IT APPEARS TO BE OVER SOUTH CENTRAL COLORADO. RIDGE CAN BE SEEN BUILDING INTO THE EASTERN PACIFIC. LATEST 08Z METARS REPORT WIDESPREAD DENSE FOG OVER A LARGE PART OF THE FORECAST AREA. KGLD RADAR RETURNS ARE NIL OVER THE TRI-STATE AREA. TODAY...THE ETA BRINGS THE TROUGH AXIS THROUGH THE FORECAST AREA BY 00Z SATURDAY. MAIN FORCING APPEARS TO OCCUR BY 12Z WITH SUBSIDENCE AFTERWARDS. SINCE PRECIPITATION HAS BEEN SCANT TO NONE AM DOUBTFUL ABOUT MUCH OF ANYTHING AFTER 12Z. ISOLATED MORNING POPS WILL PROBABLY HANDLE THE SITUATION. FOG SHOULD BEGIN TO THIN OUT AFTER 12Z WHEN THE SURFACE WIND BECOMES WEST. DEWPOINTS SHOULD ALSO DECREASE INTO THE MID 20S. DENSE FOG ADVISORY MAY NOT BE NEEDED FOR THE WESTERN ZONES IF WEST WIND MOVING INTO THAT AREA. THE EASTERN ZONES MAY NEED THE ADVISORY FOR PART OF THE MORNING. WILL NEED TO MONITOR METARS PRIOR TO ISSUANCE. NORTH WIND BEHIND EXITING SURFACE LOW SHOULD BECOME BREEZY IN THE AFTERNOON. MAV HIGH TEMPERATURES AROUND 50 LOOK GOOD. TONIGHT THROUGH SATURDAY NIGHT...A SHORTWAVE IS ADVERTISED TO MOVE DOWN THE RIDGE TONIGHT BUT SUBSIDENCE IS INDICATED OVER THE TRI-STATE AREA. THE BUILDING RIDGE SHOULD SHUNT THE DYNAMICS NORTH AND EAST OF THE AREA. NORTH WIND SHOULD DECREASE TO 10 TO 15 MPH BY MID EVENING. 850 TEMPERATURES TO 10 BELOW ZERO ADVECT INTO THE AREA TONIGHT AND SATURDAY. MAV LOW TEMPERATURES IN THE LOWER 20S SEEMS ON TRACK. LIGHT NORTHEAST WIND WILL KEEP TEMPERATURES ON THE COOLER SIDE SATURDAY. GUIDANCE TEMPERATURES ARE ADVERTISING HIGHS IN THE LOW TO MID 30S. SINCE THERE IS NO SNOW ON THE GROUND WILL OPT FOR THE MID 30S. LOW TEMPERATURES SATURDAY NIGHT SHOULD NOT GO ANY LOWER THAN THE LOWER 20S IN THE WESTERN ZONES WITH A FEW UPPER TEENS IN THE EAST ZONES DUE TO SOME EARLY MORNING WEST WIND AND SOME WARM AIR ADVECTION AT 850 MB. SUNDAY AND SUNDAY NIGHT...THE RIDGE MOVES OVER THE CENTRAL PLAINS ON SUNDAY AND THEN FLATTENS SUNDAY NIGHT IN RESPONSE TO A DISTURBANCE MOVING ACROSS THE NORTHERN PLAINS. DYNAMICS FROM THE TROUGH OVER THE NORTHERN PLAINS TOO FAR AWAY. 850 TEMPERATURES WARM TO +4 DEGREES C AND CONTINUE WARMING TO 6 DEGREES C DURING THE NIGHT. CURRENT FORECAST OF LOWER 50S LOOKS ON TRACK. EXPECT LOW TEMPERATURES TO MODERATE INTO THE MID 20S. EXTENDED...CURRENT FORECAST IS ON TRACK BUT THURSDAY IS IN QUESTION AS AN UPPER TROUGH IS FORECAST TO MOVE THROUGH. TOO EARLY TO PUT IN POPS ESPECIALLY SINCE IT IS OPEN AND MAY NOT PRODUCE ANY MORE PRECIPITATION THAN THE ONE CURRENTLY MOVING THROUGH THE AREA. WILL WAIT FOR FURTHER RUNS BEFORE MAKING CHANGES. .GLD...DENSE FOG ADVISORY THIS MORNING ALL ZONES. $$ FS ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 950 PM EST FRI FEB 14 2003 LIGHT LES NCNTRL AND MIN TEMPS ARE THE FCST CONCERNS OVERNIGHT. ICE COVER CONTINUES TO EXPAND ON LAKE SUPERIOR AND IS PROBABLY THE GREATEST COVERAGE SINCE LATE WINTER 95-96. IF YOU EXTEND A LINE NE FROM COPPER HARBOR...IT LOOKS AS THOUGH NEARLY 2/3RDS OF THE LAKE WEST OF THAT LINE HAS ICE COVER NOW. LARGEST ICE FREE AREA IS OVER THE CENTER PART OF THE EAST HALF...WHICH IS TYPICAL DURING PERIODS OF SIGNIFICANT ICE COVER. EXTREMELY DRY AIR (NOTE 00Z KINL/CWPL SOUNDINGS) COMBINED WITH ANTICYCLONIC FLOW AND DIMINISHED FETCH DUE TO ICE COVER IS PREVENTING LES FROM DEVELOPING ON THE W HALF OF LAKE SUPERIOR THIS EVENING. LAKE EFFECT CLOUDS ARE EVEN HARD TO FIND. LES PERSISTS OVER THE E HALF AND IS SHOWING SIGNS OF REINVIGORATION... THOUGH STILL QUITE LIGHT. LES ALSO BEGINNING TO SHIFT WWD AS LOW-LEVEL WINDS VEER IN RESPONSE TO HIGH BUILDING EWD TO THE N OF LAKE. GOING FCST HAS LES CONCERNS COVERED WELL. ETA/RUC SHOW NERLY LOW-LEVEL FLOW LOCKING IN OVERNIGHT AS HIGH BUILDS N OF LAKE. ERLY COMPONENT WILL BE ENHANCED OVER ERN SUPERIOR AS LAND BREEZE STRENGTHENS OFF ONTARIO. 18Z ETA AND 12Z 4KM RESOLUTION WSETA SHOW THIS RESULTING IN A ZONE OF STRONGER CONVERGENCE PROGRESSING W TWD MARQUETTE COUNTY DURING THE NIGHT AS LAND BREEZE SWEEPS WWD. SHOULDN'T REALLY AMOUNT TO MUCH IN THE WAY OF ACCUMULATING SNOW GIVEN VERY DRY AIRMASS AND SYNOPTIC SCALE ANTICYCLONIC FLOW. SHORTENED FETCH DUE TO ICE COVER WILL ALSO BE A SMALL FACTOR. MAY SEE AN INCH OR TWO OF FLUFF OVER MARQUETTE/ALGER BY SUNRISE. LINGERING LES WILL END OVER LUCE COUNTY AS COLD DRY ENERLY FLOW FROM ONTARIO DEVELOPS THERE. FROM THE KEWEENAW TO GOGEBIC...EXPECT ONLY A FEW FLURRIES UNDER N TO NERLY FLOW. NRN EDGE OF CLOUD COVER ASSOCIATED WITH SYSTEM WELL TO THE S CONTINUES TO HOLD ACROSS THE FCST AREA THIS EVENING WITH LITTLE SWD DRIFT NOTED. CLOUDS LOOK TO BE TIED TO RIGHT ENTRANCE OF UPPER JET WHICH EXTENDS FROM LAKE SUPERIOR EWD. JET IS SLOW TO DEPART...SO MID/HIGH CLOUDS WILL LIKELY HANG AROUND FOR A GOOD PART OF THE NIGHT. IF SKIES WERE CLEAR...TEMPS WOULD DROP TO -20F OR LOWER IN THE INTERIOR. GOING MIN TEMPS WITH LOW END AROUND -10F W/CNTRL AND -15 TO -20F FAR E FCST AREA LOOK TO BE IN GOOD SHAPE SINCE CLOUDS SHOULD BEGIN TO THIN OUT LATE. COLDER TEMPS E DUE TO COLD DRAINAGE OUT OF ONTARIO ACROSS FROZEN WHITEFISH BAY. ROLFSON DISCUSSION FROM PREVIOUS SHIFT FOR SAT-FRI... SAT-SUN NIGHT (WEATHER)...SNOW SHOWERS/FLURRIES CONTINUE IN SHALLOW NE FLOW SAT WITH MAYBE ANOTHER T-2" OVER NCNTRL...OTHERWISE SUNNY AND COLD WITH A LGT NE WIND. WINDS LGT/VARIABLE BY LATE SAT INTO SUN MORNING AS RIDGE CRESTS OVR CWA...WITH SCT SNOW SHOWERS/FLURRIES NEAR LK SUPERIOR DISSIPPATING. SAT-SUN NIGHT (TEMPS)...BUMPED HIGHS DOWN ON SAT AS DO NOT EXPECT MUCH MIXING AS HIGH PRES SITS OVERHEAD. SUNSHINE WILL HELP SLIGHTLY...BUT STILL WENT BLO GUIDANCE OVR NRN UPR MI AND AROUND IT OVR S ZONES. SAT NIGHT SHOULD BE BITTER COLD AS RIDGE AXIS LIES W-E ACROSS CWA. DRY AIRMASS WILL ALLOW TEMPS TO PLUMMET AND DEVELOPMENT OF LGT S COMPONENT TO WIND WILL ALLOW EVEN LK SUPERIOR SHORELINE TO DIP TOWARDS -10F. JUST INLAND EXTENDING TO WI BORDER...EXPECT READINGS COMMONLY AROUND -20F BY DAYBREAK SUN. POSSIBLY TOUCHING -30F IN THE FAVORED SPOTS. COULD BE A TOUCH WARMER ALONG LK MI. ONLY A FEW CI FM SRN STREAM SYSTEM SUN...WITH A REBOUND INTO THE TEENS CWA-WIDE. PRESIDENTS DAY (MON)...12Z MODELS HAVE TRENDED SLOWER WITH NRN STREAM TROUGH MOVING INTO UPR LAKES...NOW PUSHING IT ACROSS CWA MON NITE-TUE. CHANCE OF SNOW COMES IN AHEAD OF SHARP SHORTWAVE TROUGH THAT IS CURRENTLY PART OF LARGER PIECE OF ENERGY OVR ERN PAC. UKMET/CANADIAN DEEPER WITH TROUGH EVEN SHOWING POSSIBLE NEG TILT. SINCE ANTECEDENT AIRMASS WILL BE VERY DRY AS HIGH SLOWLY EXITS AREA WOULD THINK ANY ISENTROPIC LIFT AHEAD OF SFC TROUGH WILL ONLY RESULT IN INCREASE IN CLOUDS. EVEN THE USUALLY QUICKER GFS DOES NOT BRING DEEP H85-H7 MOISTURE/QPF INTO WRN CWA UNTIL AFT 00Z/TUE. HAVE REMOVED POPS FOR DAYTIME MON...PUSHING THEM INTO MON NITE-TUE. MAX TEMPS...DARE I SAY...30F! STRENGTHENING SW FLOW (SFC-H7)...AT LEAST A P/S SKY (CUE THE DECIDIOUS TREE EFFECT)...AND H85 TEMPS RISING TO AROUND -3C (H95/H9 TEMPS AROUND -10/-6) COULD ALLOW TEMPS TO REACH ABOVE GUIDANCE (WHICH IS 30F)...MAYBE WELL INTO 30S. FOR NOW...WENT WITH LWR 30S. EXTENDED (TUE THROUGH FRI)... A MODIFIED NRN BRANCH WILL CONTINUE TO AFFECT UPR MIDWEST INTO WRN GREAT LAKES THROUGH MID WEEK (ALTHOUGH MODELS HINT THAT COOLER AIR WILL TRY AND FILTER INTO UPR LAKES AFTER MILD MONDAY). AIRMASS ORIGIN WILL BE OFF MORE MILDER PACIFIC COMPARED TO CHILLY NW CANADA. 1000-500MB THICKNESSES PROJECTED TO RISE ABOVE 520DM...WITH H85 TEMPS MODERATING TO THE SINGLE DIGITS BLO ZERO PER GFS/ENSEMBLES. THIS WILL RESULT IN DAYTIME HIGHS TUE-THU MORE AROUND NORMAL VALUES IN THE MID-UPR 20S...WITH A DROPOFF FRI IN WAKE OF PASSING PLAINS-LAKES SRN STREAM SYSTEM. WITH MILD H85 TEMPS THROUGH NEXT THU...ONLY CHANCES FOR SNOW WILL BE TIED TO ANY SYSTEMS. THE MAIN SYSTEM APPEARS TO AFFECT AREA LATE WED INTO THU. BULK OF WED COULD TURN OUT DRY BUT KEPT PCPN CHANCE AS GFS/UKMET DEVELOP DEEPER TROUGH IN NRN BRANCH WHICH COULD PRODUCE SOME LGT SNOW/FLURRIES. WILL HAVE TO KEEP EYE ON WED NIGHT INTO THU AS STRONG SRN BRANCH STORM IS EMERGING ON ALL LATEST GUIDANCE... EXCEPT NAVY NOGAPS MODEL. ALTHOUGH GFS TAKES THIS SYSTEM TO OUR SOUTH...A WIDE OPEN GULF OF MEX AND STRONG BAROCLINIC ZONE OVR WRN GREAT LAKES MAY ALLOW A DECENT OVERRUNNING SNOW EVENT TO OCCUR FARTHER N...INTO CWA. ATTM WENT WITH CHANCE OF SNOW WED-THU AND THEN CHANCE OF SNOW SHOWERS ON FRI AS LES RESUMES AS H85 TEMPS CHILL BLO -20C. JLA .MQT...HEAVY FREEZING SPRAY E HALF LAKE SUPERIOR. mi SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1100 AM EST FRI FEB 14 2003 THE CURRENT SURFACE ANALYSIS SHOWS STRONG HIGH PRESSURE OVER SASKATCHEWAN WITH RIDGING EXTENDING INTO THE EASTERN GREAT LAKES. LOW PRESSURE CENTERED NEAR THE OKLAHOMA PANHANDLE HAS AN ASSOCIATED WARM FRONT EXTENDING EASTWARD INTO THE MID MISSISSIPPI VALLEY. STRONG ISENTROPIC LIFT ON THE 290-310K SURFACES AND DEEP FRONTOGENETICAL LIFT ACROSS SOUTHERN ILLINOIS AND INDIANA HAS LED TO WIDESPREAD PRECIPITATION IN THIS AREA. ALTHOUGH THE 12Z MESO ETA AND CURRENT RUC SHOWS SOME GOOD FRONTOGENETICAL LIFT IN THE 600-500MB LAYER DEVELOPING NEAR THE OHIO BORDER AROUND 21Z...MODEL SOUNDINGS SHOW DEEP MOISTURE LACKING. AS A RESULT...I WILL REMOVE THE CHANCE OF SNOW LATE THIS AFTERNOON FROM THE I-94 CORRIDOR TO THE STATE LINE. THE MODELS ARE STILL HAVING DIFFICULTY HANDLING THE ALTO CU DECK ACROSS CENTRAL AND NORTHERN LOWER MICHIGAN. THESE CLOUDS ARE SHOWING SIGNS OF BREAKING UP A BIT IN THE IR LOOP. HIGH CLOUDS WILL GRADUALLY OVERSPREAD THE CWA DURING THE CURSE OF THE AFTERNOON THROUGH AS THE PRECIPITATION ACROSS SOUTHERN ILLINOIS AND INDIANA SLOWLY LIFTS NORTHWARD. WITH ONLY SOME HIGH CLOUDS IN THE FAR SOUTH AND QUITE A BIT OF SUNSHINE IN THE CENTRAL COUNTIES...CURRENT FCST HIGHS LOOK ON TARGET. I WILL HOWEVER DECREASE FORECAST HIGHS A COUPLE DEGREES IN THE NORTH SINCE TEMPERATURES HAVE BEEN SLOW TO RECOVER THIS MORNING WITH ALL OF THE MID CLOUDS. .DTX...NONE. EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) CONSIDINE mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1055 AM EST FRI FEB 14 2003 ...CONSIDERABLE SUNSHINE WILL GIVE WAY TO CLOUDINESS THIS AFTERNOON... I UPDATED THE ZONES TO REFLECT MORE SUNSHINE INTO MID AFTERNOON. LOOKING OUT THE WINDOW...AND EVEN THOUGH THERE IS A BROKEN CIRRUS CLOUD DECK ABOVE...REALLY THERE IS BRIGHT SUNSHINE OUTSIDE! THE VISIBLE IMAGES CONFIRM THAT IDEA. LOOKING AT THE RUC 850 TO 700 MEAN RH (CLOUD DECK OVER THE NRN 1/2 OF THE CWA IS BETWEEN THOSE LAYERS)...IT SHOWS A TREND TOWARD THINNING CLOUDS OVER THE NORTH CWA INTO MID AFTERNOON AND NOT MUCH OF AN INCREASE OVER THE SRN CWA. THE CLOUDS IN THAT LAYER FROM THE SOUTHERN SYSTEM STAY SOUTH OF THE GRR CWA THROUGH 00Z. SO ALL WE REALLY LEFT WITH IS THE INCREASING HIGH CLOUDS. NOTE... SOUNDING SHOW IT IS TO DRY AT LOW LEVELS FOR MUCH CU TO DEVELOP. THUS I UPDATE THE ZONES FOR MORE SUNSHINE THROUGH MID AFTERNOON. HIGHS IN THE MID 20S SHOULD BE FINE ACROSS THE CWA...COULD BE A LITTLE COOLER NORTH ACTUALLY DUE THE MID CLOUDS THERE...BUT WITH THE CLOUDS THINNING EVEN THEIR...TEMPERATURES GETTING INTO THE 20S SEEMS MORE THAN POSSIBLE. NOTE ALSO...LATEST TREND FROM MODELS IT TO KEEP ALL THE SNOW SOUTH OF THE CWA. I LEFT THE ZONES ALONE WITH THAT FOR NOW...BUT IF THE AVN AND CANADIAN CONFIRM THIS TREND...I WILL LIKELY DROP THE POP TOTALLY OR REDUCE IT SIGNIFICANTLY OVER THE SOUTHERN CWA. ZONES WERE ISSUED 1042 EST. .GRR...NONE. WDM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1050 AM EST FRI FEB 14 2003 12Z RAOBS/WV LOOP AND RUC ANLSYS SHOW SPLIT FLOW OVR NAMERICA. UPR GRT LKS REMAINS DOMINATED BY NRN BRANCH NW FLOW ARND ARCTIC VORTEX OVR ERN HUDSON BAY. RATHER SHEARED SHRTWV EVIDENT NR LK WINNIPEG AND IN RRQ OF 150KT H3 JET MAX OVR ECNTRL LKS DROPPING SE IN THIS FLOW AND INTERACTING WITH SOME MID LVL MSTR DEPICTED ON 12Z INL/GRB SDNGS TO CAUSE AREA OF -SHSN OVR MN ARROWHEAD STREAMING INTO SW LK SUP/CWA. BUT 12Z INL/GRB SDNGS ALSO SHOW LLVLS QUITE DRY WITH SHARP INVRN ARND H925-95. DESPITE H85 TEMPS ARND -20C OVR LK SUP...ONLY WEAK LES BANDS EVIDENT ON 88D/SAT PIX OVR MAINLY ERN LK SUP WITH LGT WND FIELDS/LLVL DRY AIR/LO INVRN HGT/INCRSG ICE COVG SUPPRESSING ACTIVITY. MAIN FCST CONCERNS TDAY ARE SN COVG ASSOCIATED WITH LK WINNIPEG SHRTWV AS WELL AS MAX TEMPS. 12Z RUC HAS GOOD HANDLE ON OBSVD MSTR PATTERN ACRS NW GRT LKS. 06Z GFS/ETA AND 12Z RUC INDICATE UPR LVL DVGC ASSOCIATED WITH RRQ OF H3 JET MAX TO THE E AND WITH SHEARED OUT SHRTWV WL REMAIN TO THE S OF CWA DURG THE DAY. BUT RUC SHOWS PERSISTENT H5-3 QVECTOR CNVGC AND HIER RH > 70 PCT ARND H7 IMPACTING THE WI BORDER ZNS UNTIL THIS AFTN WHEN WSHFT TO MORE DIFFLUENT NNW/RISING PRES NW TO SE IN WAKE OF SHRTWV CAUSES DRY ADVCTN AND HIER MID LVL MSTR TO SHIFT TO THE S. SO XPCT SOME PTCHY -SN TO IMPACT WI BORDER ZNS BEFORE DRYING TREND IN THE AFTN. LES SHUD REMAIN WEAK/DISORGANIZED...BUT THERE MAY BE A PICK UP IN ACTIVITY THIS AFTN AS NNW FLOW INCREASES A BIT. BUT NEGATIVES MENTIONED ABV WL KEEP FCST ACCUMS BLO LK EFFECT CHART FCST...WHICH WOULD SUG UP TO 4"/6HRS. WL FCST ONLY 1-2 INCHES OVR ALGER/LUCE ZNS WHERE 06Z ETA/12Z RUC SHOW A BIT MORE H95 CNVGC AND A BIT LONGER FETCH ACRS ICE FREE CNTRL LK SUP. REST OF LK SUP SHORELINE WL SEE NO MORE THAN ONE INCH OF LES. XPCT LTL ADDITIONAL DIURNAL RISE IN TEMP ACRS THE WI BORDER ZNS WHERE CLDS WL LINGER WELL INTO THE AFTN IN ABSENCE OF WAD. ALTHOUGH 12Z ETA FCST SDNGS SHOW MAX TEMPS WL APRCH 20 OVR AREAS THAT ARE NOW PCLDY...UPSTREAM MAX TEMPS YDAY SUG READINGS WL BE LWR. WL KEEP FCST MAX IN THESE AREAS...BUT LWR FCST ALG WI BORDER. HAVE ALSO OPTED TO CANCEL WND CHILL ADVY THAT WAS IN EFFECT TNGT. ALTHOUGH COLD AIR WL DRAIN INTO NW GRT LKS AS ARCTIC HI PRES BUILDS TO THE N...XPCT PRES GRADIENT TO BE SLACK ENUF OVR CWA TO CAUSE NR SFC WNDS TO GENERALLY BE AOB 10 MPH. SO ALTHOUGH TEMPS WL FALL WELL BLO ZERO INLAND WITH RISING PRES...WND CRITERIA WL NOT BE MET FOR ADVY. .MQT...HEAVY FREEZING SPRAY WARNING LAKE SUPERIOR. KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 340 PM CST FRI FEB 14 2003 KIND OF HECTIC WITH BAND OF SN/+SN IN SRN CWA. BAND LINES UP WELL WITH RUC H85 FULL WIND FRONTOGENESIS. 88-D MOSAIC LOOPS STILL SHOWS WEAK H7 CIRC MOVG SLOWLY THRU NERN NE...DROPPING SOUTHEAST TWRD WRN IA. SNOW REALLY BLOSSOMING ON NORTHERN CUSP OF THIS CIRC WITH FRQ VIS FALLING TO >1/2SM IN SN/+SN. CALLS TO MANY CITIES/COUNTIES THOUGH SHOWING GENERALLY 1/2 TO 3/4" PER HOUR WITH THIS SNOW...WITH SOME ISOLATED 1" PER HOUR. ADVRY CRITERIA WL BE CUT CLOSE...BUT WILL HOLD OFF AS FORCING RAPIDLY DROPS SOUTHEAST WHERE BIG SNOW EVENT IS TAKING SHAPE. WL HIT HARD WITH 2-4" IN SRN TWO TIERS...AND FEEL MANY LOCALES WL BE CLOSER TO 4" THAN TO 2"...GIVEN BANDING OF SNOW SEEN ON KMPX AND IDEAL DENDRITIC TEMPS WHICH HAVE BEEN IN PLACE. RUC/META THETA SFCS SHOWING LIFT SHUTTING OFF IN A HURRY AFT ABOUT 00Z. WINDS TO BE A PBLM IN SCNTL SO MENTIONED SOME BLOWING SNOW AS DOT SCAN CAMS IN THIS AREA SHOWING BLOWING SNOW ACRS ROADWAYS. BUT NRN EDGE OF SN IS DROPPING SOUTH WITH GOOD PROGRESSION...AIDING IN DECISION TO HOLD ON ADVRY. THANKS KARX FOR THE COORD CALL. ONCE SYSTEM CLEARS CWA TO THE SOUTH...SKIES SHUD CLEAR RAPIDLY OVERNIGHT AS BIG AND VRY DRY HIGH DROPS INTO UPR MIDWEST. LTL SENSIBLE WX SAT THRU MON AFTN. VRY DRY AIR WL ALLOW FOR COLD NIGHTS AND RATHER TOLERABLE DAYS WITH PLENTY OF SUN...AND SOME CI SHIELDS ZIPPING THRU AS SYSTEMS SLIDE THRU CNTL CAN AS ZONAL FLOW TAKES OVR. NICE TROF COMES IN MONDAY AFTN/EVENING...WITH PACIFIC ORIGIN. SOME NICE TEMP ADV/ISENTROPIC LIFT...BUT ATMS QUITE DRY. WL HOLD ON POPS FOR MON...BUT BRING IN SOME FLURRIES IN CAA IN WAKE OF TROF. XTENDED VRY COMPLICATED GIVEN ARCTIC BNDRY IN PROXIMITY IN SRN CANADA...AND ZONAL FLOW STILL IN PLACE. CAN/ECMWF HINTING AT A FAIRLY GUD SYSTEM BY MIDWEEK LIFTING OUT OF THE SW...BUT NOT SEEING MUCH SUPPORT FROM GFS ET AL. ENSEMBLES POINT TO POPS ON WED...SO WILL HEAD THIS WAY GIVEN VRY LITTLE REASON TO DISPUTE. TEMPS APPEAR TO BE SEASONABLE LOOKING AT ANOMOLIES AND MEAN HEIGHTS/THICKNESSES. .MSP...NONE. $$ BINAU mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 925 AM CST FRI FEB 14 2003 CONCERN IS OBVIOUSLY IN NEXT 12 HRS. QUICK LOOKS AT 06Z ETA BUFR DATA AND 12Z RUC LEADS ME TO BELIEVE GOING FCST HAS THINGS WELL IN HAND. INCREASING RETURNS ON KMPX 88-D FROM LITTLE FALLS TO KEAU DIRECTLY TIED TO RRQ OF DEPARTING H3 JET. LIFT IS CENTERED HIGH IN TROP AND ONLY EXPECT SCT FLURYS WITH THIS. THIS REGION ALSO BEING AFFECTED BY DRY ELY LL FLOW THE MOST...AS LOW SFC/H9 TD'S CONTINUE TO STREAM IN. MORE IMPORTANTLY...LARGE SHIED OF MIXED WINTER PRECIP CONTINUES TO INCREASE IN ADVANCE OF WEAK H7 CIRC SEEN IN MOSAIC 88-D COMPOSITES...DRIFTING ALONG SD/NE BORDER. THIS CIRC FCST TO DROP SE INTO IA THRU DAY...AND SEEING THIS NOW IN RADAR ELEMENTS NEAR CIRC. BEST SHOT OF PRECIP TO OCCUR IN SWRN CWA FROM ~16-22Z FROM KMVE SOUTHEAST TO KAEL. MOISTURE IS PLENTIFUL...WITH 2.5-3.5 G/KG ON 290/295K THETA SFCS IN SAID AREA. BEST ISENTROPIC LIFT OCCURS LATE MORNING/EARLY AFTERNOON IN SWRN CWA...AND ALSO SEE A NICE DEVELOPMENT IN H7-H6 LAYER 2-D FWF AXIS OVR SRN CWA...WHICH SINKS INTO IA. PRECIP NOW MOVING IN WILL ALSO SEE A LITTLE ENHANCEMENT FROM DEPARTING H3 JET AS WELL. DENDRITIC GROWTH POTENTIAL SEEMS THE BEST IN MY CWA IN AREA OF CONCERN...WITH ALSO SOME SAT -EPV LAYERS. BUFR DATA ALSO SHOWS BEST LIFT/HIGHEST RH/AND IDEAL DENDRITIC ZONE ALL CO-LOCATED IN NARROW BAND WHERE CURRENT FCST HAS HIGHEST ACCUMS (3-6" IN FAR SWRN/SRN TIER OF CNTIES). THERE MAY BE A BRIEF PD OF SLEET AT ONSET...BUT DRY LOW LEVELS SUGGEST WBZ SHUD GO TO ZERO WITH SATN. CONCERN IN THIS SITN IS ALWAYS OVERCOMING DRY ELY LL FLOW...BUT GIVEN STRENGTH OF LIFT AND INCOMING PRECIP...THIS SHUD OCCUR QUICKLY. SHARP CUTOFF TO THE NORTHEAST...WITH LITTLE MORE THAN FLURRIES IN CNTL/NERN CWA. NO UPDATES PLANNED ATTM. .MSP...WINTER WEATHER ADVISORY TODAY PORTION OF SWRN MN FROM CANBY TO REDWOOD FALLS...NEW ULM...ST JAMES AND FAIRMONT AND BLUE EARTH. $$ BINAU mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 330 PM CST FRI FEB 14 2003 FORECAST CHALLENGES THIS FORECAST PKG WILL BE HEAVY SNOW POTENTIAL AND WINDS THRU 36HRS. PRECIP CHANGE OVER FROM RAIN TO FREEZING RAIN AND SLEET...TO SNOW IN SHORT TERM...AND CHC PRECIP WED INTO THU. SYNOPSIS...THE LATEST SUBJECTIVE SURFACE ANALYSIS...HAD SFC LOW PRES OVR SCNTRL KS WITH A WARM FRONT INTO SE NEB AND A WEAKENING INVERTED TROF INTO CNTRL NEB. VERY HIGH DEWPOINTS IN THE 60S WERE IN SE KS AND TEMPS IN THE 70S. SFC DEWPOINTS WERE AROUND 40 IN SE NEB/SW IA AND IN THE LOWER 30S FOR THE NORTHERN PORTION OF THE FCST AREA. THE UA ANALYSIS HAD A BROAD AREA OF 60M HT FALLS OVR THE ROCKIES AND SHORT WAVE TROFS OVR MT/WY AND CO/NM/TX. HIGH H85 DEWPOINTS HAD INCREASED TO 7-11 DEGREES C OVR ERN KS AND MO...WITH THE H85 DEPOINT AT OMA AROUND 5. MOST OF THE OAX CWA HAS ESCAPED THE WINTRY PRECIP SO FAR...HOWEVER...THE NELIGH PROFILER HAS BEEN SHOWING INCREASING NE WINDS AND TEMPERATURES HAVE BEGUN TO DROP NEAR THE SD BORDER IN NE NEB. WSR-88D TRENDS SHOW A LARGE AREA OF PREC OVR MUCH OF NEB...ERN SD AND IA...WITH A PRECIP BAND INCREASING BETWEEN OLU AND ODX THRU HLC. THE WATER VAPOR STLT PICS/RUC H30 SHOW A STG JET ACRS CNTRL TX AND ANOTHER JET ACRS THE NRN GRTLKS. FORECAST...THE SHORT RANGE MODELS ARE IN DECENT AGREEMENT WITH THE MASS FIELDS AS THE SHORT WAVE TROF OVR THE ROCKIES MOVES INTO THE PLAINS TONIGHT AND GRADUALLY SHIFTS EAST SATURDAY. THE ETA/GFS ARE PROGRESSIVE WITH THIS WAVE...SLIGHTLY STRENGTHENING IT OVR NRN MO/IA BY SUN AM. THE FORECAST AREA IS TO RMN UNDER UVV/WAA WITH ABUNDANT RH WITH THE APPROACH OF THE SHORTWAVE TROF...ESPECIALLY THROUGH 12Z...AND IN SE NEB AND SW IOWA THRU SAT AM. HAVE DECIDED TO UPGRADE WINTER WEATHER ADVISORY AND ISSUE A WINTER STORM WARNING DUE TO EXPECTED SNOWFALL AMOUNTS TONIGHT AND SAT AM. IN ADDITION THE SNOW WILL BE ACCOMPANIED BY STRONG WINDS. THE POTENTIAL FOR HEAVY SNOW IS CONSISTENT WITH THE 06ZGFS AND THE 18ZMESOETA. THIS EVENING...THERE IS SOME POTENTIAL FOR CONVECTIVELY ENHANCED SNOWFALL WITH SOME CSI/EPV/STEEP LAPSE RATES NOTED AND STRG ISENTROPIC LIFT ECNTRL NEB/SW IA. USING THE FORECAST SOUNDINGS HAVE TRENDED THE CHANGE OVR FM RAIN TO SNOW FM N TO S THIS EVENING AND INCLUDED SOME MENTION OF BRIEF PERIODS OF FREEZING RAIN AND SLEET BEFORE THE RAIN CHANGES TO ALL SNOW. THE SNOW CONTINUES FOR THE SOUTHEAST CWFA SATURDAY MORNING BEFORE TAPERING TO FLURRIES LATE. TONIGHT...HAVE LOWS IN THE TEENS AND 20S...WITH SINGLE DIGITS AN SUN AM AND 30S FOR SUN. IN LATER PERIODS...ETA/GFS TRACK A COUPLE OF SFC LOW ACRS SRN CANADA WITH A FRONTAL PASSAGE MONDAY AFTERNOON...HOWEVER THE COOL AIR RMNS WELL TO THE NORTH. THE GFS AND SLIGHTLY STRONGER CANADIAN BRING A SFC LOW ACROSS THE ROCKIES AND DEEPEN IT OVR OK AND KS. HAVE INCREASED POPS WITH RAIN S AND MIXED PRECIP N...THEN RAIN CHANGING TO SNOW WED NIGHT AND LINGERING CHC -SN FRI AM. THANKS FOR THE COORD FSD/GID/TOP/LBF/DSM/EAX .OMA...WINTER WEATHER ADVISORY TONIGHT AND SATURDAY MORNING NORTHEAST NEBRASKA NEZ011-012-015>017-018-030-031>033. WINTER STORM WARNING TONIGHT AND SATURDAY EAST CENTRAL AND WRN IOWA NEZ034-042>045-050>053-065>068-088-089-090-IAZ043-055-056-069-079- 080-090-091. WINTER WEATHER ADVISORY TONIGHT AND SATURDAY FOR SOUTHEAST NEBRASKA NEZ091-092-093. ZAPOTOCNY ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE UPTON NY 915 PM EST FRI FEB 14 2003 THE BATTLE IS ON BETWEEN STRONG HIGH TO THE NORTH AND FRONTAL BOUNDARY ACROSS THE CENTRAL APPALACHIANS. BY SUNDAY MORNING...HIGH MAXES OUT AT 1048 MB. IN THE SHORT TERM...TREND HAS BEEN TO KEEP PRECIPITATION FURTHER SOUTH. IN FACT...RUC BARELY SKIMS THE AREA. 18Z RUN OF THE ETA ONLY BRINGS LIGHT QPF IN FOR AN HOUR OR TWO SAT MORNING. FLOW IN THE MID LEVELS IS ORIENTED WNW-ESE...GOING TO BE TOUGH TO ADVECT MUCH MOISTURE IN HERE. WITH LOW WELL SOUTH AND WEST OF THE REGION...DYNAMICS ARE ALSO WEAK. WILL BE UPDATING TO REDUCE ACCUMULATIONS TOMORROW TO A DUSTING. SNOW WILL BE QUITE DRY AND MAY HAVE A TOUGH TIME ACCUMULATING. LATEST RUN OF THE GFS NOT VERY ENCOURAGING FOR SUNDAY INTO MONDAY EVENT. STRONG HIGH WITH CLASSIC DAMMING LOOKS TO WIN OUT. HEAVY SNOW A BETTER BET ACROSS MID-ATLANTIC. HOWEVER...THE SITUATION STILL WARRANTS A WINTER STORM OUTLOOK. UPDATED EXTENDED THU AND FRI. WE ARE ON WARM SIDE OF SYSTEM WHICH LOOKS TO BE PREDOMINANTLY RAIN. ********************* PREVIOUS DISCUSSION ************************* 430 PM EST FRI FEB 14 2003 FOR TNGT...WE/LL BE ON THE NRN FRINGE OF THE AREA OF SNOW. MDLS IN GENERAL AGREEMENT. WENT WITH THE AVN...WHICH COMES UP WITH A DUSTING TO AN INCH OF SNOW ALONG THE COAST. ACRS NRN INTERIOR ZONES...JUST CHC POPS. FAIR BUT COLD WX SAT AFTN THRU MIDDAY SUN WITH ARCTIC HIGH NOSING INTO THE AREA. LATE SUN THRU MON...TIMING DIFFERS A BIT BETWEEN THE AVN AND THE ETA BUT THE END RESULT IS SIMILAR. I'LL FCST CHC SNOW TWDS EVE SUN... THEN SNOW SUN NGT AND MON. I'LL REISSUE THE SPS OUTLOOK. MARINE...WINDS AND SEAS HAVE COME DOWN...SO WILL LOWER SCA WITH THIS PKG. WL HEADLINE SCA MAY BE NEEDED FOR SAT. ******************************************************************* .OKX... CT...NONE. NJ...NONE. NY...NONE. MARINE...NONE. $$ ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 910 PM EST FRI FEB 14 2003 ONLY A FEW MINOR TWEEKS FOR THE EVNG UPDATE. AT THIS POINT I'M THINKING WE WON'T SEE ANY SNOW ACRS OUR NE PA COUNTIES. LOW LVLS ARE VERY DRY AND MAV/FWC/MET SHOWS SFC TD'S FALLING LATER TNGT INTO SAT MRNG. RUC KEEPS PCPN SOUTH OF THE BGM CWA THRU 12Z AND SUGGESTS IT WILL STAY SOUTH, AND RDR COMPOSITE IS PICKING UP ALOT OF VIRGA OVER OH. WILL KEEP A 30 POP FOR CONTINUITY BUT DELAY PSBLTY OF -SN FROM 'AFTER MDNGT' TO 'AROUND DAYBREAK'. MAYBE SOME MINOR CLD/MIN TEMP TWEEKS ELSEWHERE, OTRW THAT'S IT. ---------------------------------------------------------------- OVERALL FORECAST THROUGH THE SHORT TERM IS DRY BUT COLD WITH A LITTLE BIT OF LAKE EFFECT SNOW AND THE MAIN BRUNT OF MAJOR SOUTHERN STREAM SYSTEMS STAYING WELL TO OUR SOUTH. MEANWHILE, CURRENT RADARS STILL SHOWING SNOW SHOWER ACTIVITY EAST OF THE LAKES THIS AFTERNOON AND THIS WILL CONTINUE INTO THIS EVENING BEFORE INVERSION LOWERS OVERNIGHT. HIGH PRESSURE BUILDING RIDGE BUILDING SOUTH ACROSS EASTERN CANADA AND INTO THE NORTHEAST OVERNIGHT WILL KEEP MOST OF THE PRECIP ASSOCIATED WITH SHORTWAVE MOVING FROM OHIO VALLEY TO SRN NJ WELL SOUTH OF OUR FORECAST AREA. THE BEST LIFT (STILL WEAK) AND DEEPEST MOISTURE ACROSS NORTHEAST PA OCCURS FROM 06-12Z. ANOTHER NEGATING FACTOR FOR PRECIP ACROSS NORTHERN PA IS THE VERY DRY ATMOS WITH DEWPOINTS NEAR ZERO. SNOW ALOFT WILL LIKELY HAVE A DIFFICULT TIME MAKING IT TO THE SFC. WILL KEEP CHC PRECIP TONIGHT ACROSS PA ZONES AND DRY ELSEWHERE. ON SATURDAY, SOUTHERN SYSTEM EXITS OFF THE EAST COAST WITH SOME LEFT OVER CLDS, AND SMALL CHC SNOW SOUTHEAST ZONES DURING THE MORNING. COLD AND DRY AIR CONTINUES TO PUSH SOUTH WITH CANADIAN HIGH PRESSURE SYSTEM. SATURDAY NIGHT WILL FEATURE MAINLY CLEAR SKIES AND VERY COLD MINS. QUITE POSSIBLY THE COLDEST NIGHT OF THE SEASON WITH MINS -10 TO -20 ACROSS CENTRAL AND NORTHERN ZONES. SUNDAY WILL START OFF WITH SUNSHINE BUT AS THE HIGH MOVES EAST AND AND SECOND WAVE FROM SOUTHERN STREAM PUSHES NORTH, WILL SEE AN INCREASE IN CLOUDS ACROSS THE SOUTH. GFS IS A BIT FASTER WITH CLDS AND PRECIP CHCS DURING SUNDAY, ALTHOUGH STILL LATE IN THE DAY FOR PRECIP WHILE THE ETA HOLDS OFF ANY PRECIP UNTIL SUNDAY NIGHT. DAYS 3-7...OVER THE SUNDAY NIGHT THROUGH FRIDAY PERIOD, THE WESTERN NOAM RIDGE IS FORECAST TO BREAK DOWN WITH THE PERSISTENT +PNA TELECONNECTION EXPECTED TO FLUX TOWARD NEUTRAL. THIS WILL RELEASE THE GRIP OF BELOW NORMAL TEMPERATURES OVER THE NORTHEAST US AS POLAR JETSTREAM BECOMES MORE ZONAL. THERE ARE TWO POSSIBLE SIGNIFICANT WEATHER MAKERS DURING THIS PERIOD...BOTH OCCURING ON THE EDGES OF THIS FORECAST BLOCK. MOST MEDIUM RANGE MODELS ARE IN AGREEMENT WITH A CYCLONE COMING OUT OF THE SOUTHERN STREAM AND OFF THE MID-ATLANTIC COAST MON/TUE. 00Z CANADIAN OPERATIONAL MODEL WAS AN OUTLIER WITH A LOW DEEPENING...SLOW MOVING AND HUGGING THE COAST WITH SIG PRECIP FOR CENTRAL NY AND NE PA. GFS/EURO/NOGAPS/UK PUSHED SYSTEM OFFSHORE. MOST ENSEMBLES FROM BOTH GFS AND CAN WERE SUPPRESSING LOW TOO FAR SOUTH OF THIS AREA FOR IMPACT. BUT...NORTHWESTWARD TRENDS IN THE OP RUNS ARE WITHIN THE ENSEMBLE ENVELOPE AND WITH A FLUXING TELECONNECTION IT'S WORTHY TO WATCH THE DEEP STORM SCENARIO VERY CLOSELY. SUN NITE-MON WILL HAVE AT LEAST SOME LIGHT SNOW WITH THE UPPER LOWS PARTICULARLY NE PA. LITTLE OF CONSEQUENCE WITH WEAK SYSTEMS PASSING THROUGH UNTIL A STRONGER FRONT AND GOOD MOISTURE CONNECTION THURSDAY NIGHT AND FRI. TEMPS BACK TOWARD SEASONAL NORMS BY THEN SO PRECIP TYPE BECOMES A QUESTION. COULD SEE THE WHOLE MIXED BAG WITH ELEVATION A PLAYER BETWEEN RAIN/SNOW/ICE. .BGM...NONE. JML/JAB/RHB ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 1052 AM EST FRI FEB 14 2003 WILL EXTEND WINTER WEATHER ADVISORY FOR OUR NORTHERN MOUNTAIN COUNTIES THROUGH THIS AFTERNOON...PER RUC AND 09Z ETA SOUNDINGS...WHICH SHOW ABUNDANT DRY AIR AND WET BULBS BELOW FREEZING UNTIL LATE IN THE AFTERNOON PERIOD...DESPITE IMPRESSIVE LOW LEVEL WARM ADVECTION ON UPPER AIR ANALYSIS. RUC A BIT HIGHER WITH PRECIP AMOUNTS...AND SUSPECT WE MAY NOT SEE QUITE AS MUCH AS IT IS ADVERTISING BY LATE AFTERNOON...BUT WILL INCREASE SNOW AMOUNTS TO BETWEEN 2 AND 3 INCHES. WILL ALSO EXTEND ADVISORY ONE TIER SOUTHWESTWARD...TO INCLUDE MADISON...BUNCOMBE AND HENDERSON COUNTIES...WITH ACCUMULATIONS AN INCH OR LESS. ATMOSPHERIC COLUMN SHOULD WARM ENOUGH THERE BY LATE AFTERNOON TO CHANGE ANY OF THE ADVANCING PRECIP SHIELD TO ALL RAIN...BUT A BRIEF EARLY BURST OF SNOW COULD OCCUR...ESPECIALLY WITH THE HIGHER REFLECTIVITIES MOVING NOW INTO THE CWFA PER KGSP 88-D. OTHER CHANGES INCLUDE INTRODUCTION OF A RAIN/SNOW MIX FOR ALL AREAS...EXCEPT THE EXTREME SOUTHERN TIER ZONES (ABBEVILLE/GREENWOOD/ELBERT). DESPITE SURFACE TEMPERATURES IN THE UPPER 40S IN SOME OF THESE AREAS...POTENTIAL FOR EVAPORATIVE COOLING AND BRIEF ISOTHERMAL LAYER ON FORECAST SOUNDINGS DOES SUPPORT A BRIEF RAIN/SNOW MIXTURE...WHICH WOULD ERODE QUICKLY FROM THE UPSTATE AND NORTHEAST GEORGIA NORTHWARD AS THE AFTERNOON PROGRESSES. WILL NOT ADVERTISE ANY ACCUMULATIONS FOR THESE RAIN/SNOW MIX AREAS. WARM ADVECTION IS VERY STRONG AT PRESENT PER UPPER AIR ANALYSIS...FROM 85H THROUGH 50H...THUS WE DO EXPECT THE PRECIP TYPE TO BECOME ALL RAIN FOR MOST AREAS BY LATE AFTERNOON. HOWEVER...SOUNDINGS PROBLEMATIC FOR OUR NORTHERN TIER...WITH MOST OF THE SOUNDINGS SIGNIFICANTLY BELOW FREEZING EVEN AS LATE AS 00Z ACROSS NORTHERN MOUNTAINS. TO THE EAST...FOR THE NORTHERN FOOTHILLS AND NORTHWEST PIEDMONT...SOUNDINGS SHOW WARMING ENOUGH IN THE FAVORED SNOW CRYSTAL GROWTH LAYER TO FEEL FAIRLY CONFIDENT THAT PRECIP WILL CHANGE OVER TO ALL RAIN FOOTHILLS/AND PIEDMONT...BUT THERE COULD STILL BE A LITTLE FROZEN AND HENCE THE INTRODUCTION OF THE MIXTURE...EVEN IN AREAS THAT HAVE FORECAST MAXES INTO THE 50S. TEMPERATURES WERE ADJUSTED DOWNWARD FOR THE UPDATE ALL AREAS...EXCEPT SOUTHERN TIER...WITH RAIN...CLOUDS AND EVAPORATIVE COOLING HELPING OFFSET SOMEWHAT THE VERY STRONG WARM ADVECTION. ALSO RAISED POPS TO CATEGORICAL ALL AREAS BY LATE AFTERNOON EXCEPT NORTHWEST PIEDMONT. FCSTID = 44 GSP 51 42 53 34 / 60 70 70 80 AND 52 43 54 35 / 50 70 70 80 CLT 51 42 52 30 / 70 70 70 80 HKY 48 40 47 27 / 80 80 80 80 AVL 46 40 49 34 / 80 80 70 80 .GSP... GA...NONE. NC...WINTER WEATHER ADVISORY FOR TODAY FOR ZONES NCZ033...NCZ049>050. WINTER WEATHER ADVISORY FOR TODAY FOR ZONES NCZ048...NCZ053...NCZ065. SC...NONE. BURRUS sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 1007 AM EST FRI FEB 14 2003 DISC...14Z SURFACE ANALYSIS SHOWS SURFACE HIGH PRESSURE ALONG THE CAROLINA COAST. DEVELOPING LOW PRESSURE ACROSS THE CNTRL/SRN PLAINS. SATELLITE SHOWS LOTS OF MID/HIGH CLOUDS ACROSS THE AREA THIS MORNING WITH SOME LOWER CLOUDS TO OUR NW IN AREAS OF LIGHT RAIN SHOWERS. TEMPERATURES OFF TO SLOWER THAN EXPECTED START THIS MORNING WITH EXTENSIVE CLOUDINESS. MORNING RUC/MESOETA SHOW S/W TO MOVE ACROSS THE AREA...MAINLY AFFECTING THE WESTERN PORTIONS...THIS AFTERNOON. RUC AND MESO ETA ALSO SHOW GOOD WAA DEVELOPING ACROSS THE AREA THIS AFTERNOON ALONG WITH SOME THINNING OF THE CLOUDINESS ACROSS THE SOUTHERN PORTONS OF THE CWA THIS AFTERNOON. THINK FORECAST MAXES IN GOOD SHAPE THERE...BUT MAY NEED TO BE TWEAKED DOWNWARD SLIGHTLY ACROSS THE NORTHERN AND CENTRAL PORTIONS AS CLOUDS HOLD TEMPERATURES DOWN SLIGHTLY. FCSTID = 77 CAE 59 47 66 48 / 30 40 50 60 AGS 61 47 70 52 / 30 40 50 60 SSC 58 47 66 48 / 30 40 50 60 OGB 61 48 70 52 / 30 30 40 60 .CAE... GA...NONE. SC...NONE. LCV sc AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 410 PM CST FRI FEB 14 2003 STRONG WINTER STORM WL BEGIN TO TAPER OFF THIS EVENING. STRONG LOW LVL THERMAL GRADIENT...AND LOW LVL THTE RIDGING CONT TO PUMP UP THRU THE SRN AND WRN PARTS OF THE FSD CWA THRU THE EVENING HRS. THIS THTE RIDGING THEN BEGINS TO ERODE...AND DROP A LITTLE SWD AFTER MIDNIGHT. AND AS THE LIFT WANES...MOST OF THE CWA SHOULD BE PCPN FREE AFTER MIDNIGHT EXCEPT FOR THE MO VALLEY ARND YANKTON AND SIOUX CITY...WHERE A LITTLE -SN MAY HANG ON AFTER MIDNIGHT. ICING AMNTS OVER QUARTER OF AN INCH HAVE BEEN WIDESPREAD IN THE WARNED AREA TDAY...AND NOW EXPECTING THREE TO FIVE INCHES ON TOP OF THAT THRU THE EVENING. ICING AMNTS HAVE BEEN LESS TO THE NORTH OF I 90 WHERE THE CHANGEOVER TO SNOW WAS QUICKER...AND LESS IN THE MO VALLEY WHERE TEMPS WERE JUST ABOVE FRZING FOR MUCH OF TDAY. ALTHOUGH THE MO VALLEY COULD SEE A MIX VERY EARLY THIS EVENING...ALL MODEL SNDGS ARE SHOWING A FINAL CHANGEOVER TO SNOW RATHER QUICKLY. WINDS WL BE UP TNGT...WITH A GOOD GRADIENT AND STRONG WINDS ALOFT. COULD BE SOME BLSN AND DRSN BUT IT IS RATHER WET AND HEAVY AND WON'T MENTION IN THE ZONES. THE WINDS COUPLED WITH THE CLD COVER WL HELP KEEP LOWS SLIGHTLY ABOVE THE FWC GUIDANCE TNGT...AND WL ABOVE THE MET/MAV GUIDANCE. SFC RIDGING THEN BACKS INTO THE CWA FM LARGE GRTLKS HIGH PRES TO THE NE FOR SATURDAY. THIS WL CREATE A LIGHTER E TO NERLY FETCH...NOT GOOD FOR WARMING ESP OVER THE NEW SNOW COVER. ALSO...HIGH AMNTS OF MID TO HIGH LEVEL MSTR ARE STILL FCST SO MOSTLY CLDY SKIES ARE IN THE OFFING. KEPT TEMPS A LITTLE BLO GUIDANCE. SHORTWV RIDGING THEN BUILDS OVER THE AREA LATER SAT NIGHT AND SUNDAY. SFC WINDS REMAIN OUT OF SSE DIRECTION ON SUNDAY. THEREFORE TEMPS WL LIKELY WARM...BUT NOT AS WARM AS GUIDANCE WITH THE FRESH SNOW COVER AND WIND DIRECTION NOT CONDUCIVE TO FULL MIXING. BUT MASSIVE WAA MOVES INTO THE CWA SUNDAY NIGHT...SO TEMPS WL PROBABLY RISE SUNDAY NIGHT AFTER MIDNIGHT. DECENT MELTING DAYS WL THEREFORE OCCUR ON MONDAY AND TUESDAY WITH SOME MIXING POTENTIAL AND MILD 850MB TEMPS. KEPT TEMPS A LITTLE BLO MEX GUIDANCE HOWEVER WITH THE SNOW COVER. THE EXTENDED IS INTERESTING DURING THE MIDDLE OF THE WEEK. LAST NIGHT'S GFS SHOWED A STRONG TREND TOWARD A NRN STREAM SYSTEM COMING DOWN AND CUTTING OFF THE NRN PLAINS FM THE SRN STREAM SYSTEM MOVG THRU THE CNTRL PLAINS. HOWEVER...THE ECMWF/CAN SPECTRAL AND UKMET ALL SHOWED SOLNS FURTHER NORTH...WITH NOT MUCH OF A NRN STREAM INFLUENCE. THE CAN SPECTRAL WAS A LITTLE FASTER THAN THE ECMWF...BUT BOTH MODELS SHOWED A PRETTY GOOD STORM SOMEWHERE IN THE MIDDLE OF THE WEEK WITH THEIR STORM TRACKS. THE 12Z GFS SHOWED A STRONG TREND TOWARD THESE OTHER SOLNS...WITH MUCH LESS NRN STREAM INFLUENCE AND KEEPING THE CANADIAN FRONT AT BAY UNTIL THU NIGHT OR FRIDAY. ALTHOUGH THE 12Z GFS KEPT THE QPF SOUTH OF THE FSD FA...THE GFS/ETA MODELS HAVE NOT BEEN HANDLING THESE SRN STREAM SOLNS WELL AT ALL IN BRINGING PCPN FAR ENUF NORTH INTO THIS AREA...WITNESS TODAY. THEREFORE AM BUYING MORE OF A ECMWF/CAN SPECTRAL SOLN IN BRINGING ANOTHER POTENTIAL SYSTEM INTO THE AREA MID WEEK...WITH WAA ON WED AND WRAP ARND SNOW ON THURSDAY. WE'LL SEE. HECTIC MORNING WITH TASTE OF WINTER WEATHER FOR MOST AREA... AND CONCERNS ARE GOING HIGHLIGHTS. SIGNIFICANT ICE STORM FROM PARTS OF SERN SD INTO NWRN IA AND ADJACENT SWRN MN. WARM AIR ALFT AHEAD OF MID LVL CIRC IN CNTRL SD SLIDING SOUTHEAST...INTO KSUX VCNTY THIS EVENING. FAIRLY GOOD MID LVL FRONTOGENESIS AND SPEED DIVERGENCE HANGS TOUGH IN SWRN MN THRU DAY AND INTO EVNG...SLOWLY DROPPING SWRD WITH MID LVL CIRC CNTR. INTERACTION OF JET/FRONT WL ENHANCE PCPN ESPLY NR I29 CORRIDOR INTO EVNG. WARM SFC TMPS LINGER ALG MO RVR WITH ONLY A COLD RAIN THUS FAR...BUT FEED OF DRIER AIR INTO NERN CWA. CONTINUED COOLING LEADING TO TRANSITION OF TYPES MORE RAPIDLY IN NRN AND ERN CWA. LACK OF ICING FOR ERN AREAS AS WET BULBED DOWN BLO ZERO AS PRECIP MOVED IN MID MORNING...WITH ONLY BRIEF ICING FOR KBKX...K60Y...AND KMJQ. DROPPED WARNING TO ADVY AS ICING WAS PRIMARY INGREDIENT FOR WARNING REASONING. HOWEVER...CHANGEOVER HAS ACCELERATED SOUTH IN PAST HALF HOUR WITH QUICK CHANGE IN KFSD AND KHON...MUST FASTER THAN 12Z RUC/ETA RAOBS SUGGESTED. WL BE UPDATING ALL PRODUCTS SHORTLY TO QUICKEN CHANGEOVER...AND UP ACCUMULATIONS A BIT. .FSD...WINTER WX ADV UNTIL 7 PM FOR FM HURON...BROOKINGS...MARSHALL AND TO JACKSON MN. WINTER STORM WARNING UNTIL 9 PM ALONG THE I 90 CORRIDOR AND TO SPENCER AND STORM LAKE IA. WINTER WX ADV UNTIL 11 PM FOR THE MO VALLEY INCLUDING SIOUX CITY...VERMILLION...YANKTON AND CHAMBERLAIN. $$ MJF sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1210 PM CST FRI FEB 14 2003 HECTIC MORNING WITH TASTE OF WINTER WEATHER FOR MOST AREA... AND CONCERNS ARE GOING HIGHLIGHTS. SIGNIFICANT ICE STORM FROM PARTS OF SERN SD INTO NWRN IA AND ADJACENT SWRN MN. WARM AIR ALFT AHEAD OF MID LVL CIRC IN CNTRL SD SLIDING SOUTHEAST...INTO KSUX VCNTY THIS EVENING. FAIRLY GOOD MID LVL FRONTOGENESIS AND SPEED DIVERGENCE HANGS TOUGH IN SWRN MN THRU DAY AND INTO EVNG...SLOWLY DROPPING SWRD WITH MID LVL CIRC CNTR. INTERACTION OF JET/FRONT WL ENHANCE PCPN ESPLY NR I29 CORRIDOR INTO EVNG. WARM SFC TMPS LINGER ALG MO RVR WITH ONLY A COLD RAIN THUS FAR...BUT FEED OF DRIER AIR INTO NERN CWA. CONTINUED COOLING LEADING TO TRANSITION OF TYPES MORE RAPIDLY IN NRN AND ERN CWA. LACK OF ICING FOR ERN AREAS AS WET BULBED DOWN BLO ZERO AS PRECIP MOVED IN MID MORNING...WITH ONLY BRIEF ICING FOR KBKX...K60Y...AND KMJQ. DROPPED WARNING TO ADVY AS ICING WAS PRIMARY INGREDIENT FOR WARNING REASONING. HOWEVER...CHANGEOVER HAS ACCELERATED SOUTH IN PAST HALF HOUR WITH QUICK CHANGE IN KFSD AND KHON...MUST FASTER THAN 12Z RUC/ETA RAOBS SUGGESTED. WL BE UPDATING ALL PRODUCTS SHORTLY TO QUICKEN CHANGEOVER...AND UP ACCUMULATIONS A BIT. .FSD...WINTER STORM WARNING TODAY AND THIS EVENING IAZ001>003- 012>014-021-022-MNZ089-097-098-SDZ055-056-061-062-066-067 WINTER WEATHER ADVISORY THROUGH THIS EVENING MNZ071-072- 080-081-090-SDZ038>040-052>054 WINTER WEATHER ADVISORY THIS AFTERNOON AND EVENING IAZ020- 031-032-NEZ013-014-SDZ050-057>060-063-064-065-068>071 $$ CHAPMAN sd DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 300 PM CST FRI FEB 14 2003 TONIGHT THRU MON...AFTN VIS SAT IMAGERY DEPICTS EXTENSIVE CLD COVER OVER DPSOTEX EXTENDING OVER THE COASTAL PLAINS INTO NE TX...IN LINE WITH H85 THETA-E RIDGE PROGGED BY THE RUC80. MOISTURE WAS TRAPPED UNDER H9 CAP...SO PARTLY CLOUDY SKIES DID NOT MATERIALIZE. GOOD NEWS IS THAT CLOUD COVER HAS KEPT TEMPS FROM WARMING INTO THE MID 80S...SO 900MB CAP WAS SLOW TO BREAK THUS PREVENTING STRONG LOW LEVEL WINDS FROM MIXING DOWN AS OCCURRED YDA. CONVECTION OVER CNTRL AND E TX ASSOC WITH VORT MAX EXITING THE REGION. ANOTHER SHOT OF PVA LIFTING OUT OF THE BIG BEND EARLY THIS AFTN...AHD OF H5 TROUGH WHICH IS EXPECTED TO ENTER W TX TONIGHT AND OVER COAHUILA BY EARLY SAT. THIS SYSTEM WILL DESTABILIZE DPSOTEX ATMOS...BRINGING CHC OF SHRA/TSRA TONIGHT AND EARLY SAT. MOS POPS RANGE FROM 17 TO 47 PERCENT FOR TONIGHT...SO CURRENT 30 PERCENT A REASONABLE COMPROMISE. WILL ADD TSRA FOR SAT AM...AS ETA PROGS VORT MAX/SFC LOW TANDEM TO LIFT OUT OF NE MEX TONIGHT AND ACRS DPSOTEX EARLY TMRW. FRI AM SVR WX OUTLOOK HAS GEN TSTMS NORTH OF CWA FOR TONIGHT...AND ACRS NE PTN ON SAT. BEARS WATCHING FOR ROGUE OUTFLOW BOUNDARIES DRIFTING INTO DPSOTEX TMRW. PREFRONTAL TROUGH WILL SHIFT WINDS TO NW EARLY SAT WITH COOLER AIR ENTERING CWA DURG LATE EVENING. LITTLE MOISTURE FOR CLOUDS ON SUN AND MON WITH SFC RIDGE AND NW FLOW AT MID/UPR LEVELS. WITH CLEAR SKIES MON AM...WENT A LITTLE COOLER OUT W...NEAR 40...TO UPR 40S COAST. TUE THRU FRI...SFC RIDGE MOVES OFFSHORE MON NIGHT...SO WEAK RETURN FLOW AND WARMUP BEGIN AHD OF WEAK H5 TROUGH MOVG ACRS SW CONUS. LLJ OVR DPSOTEX INCREASES TO MOD ON WED...AS UPR TROUGH ADVANCES INTO HIGH PLAINS EARLY WED. BY THEN...MAX/MIN TEMPS SHUD BE 2-7 DEG ABV NORMAL. BY EARLY THU...SFC TROUGH CROSSING NRN MEX REACHES DPSOTEX AND H5 TROUGH LIFTS NE OUT OF NM...SO ONLY ISOLD CONVECTION EXPECTED OVER CWA ON THU AHD OF WEAK PAC COLD FRONT. MOSTLY CLR FRI WITH N WINDS VEERING TO EAST LATE WITH MIN TEMPS MID 50S TO NEAR 60 COAST. MARINE...BOY020 REPORTED A WIND FROM THE SOUTHEAST AT 12 TO 17 KNOTS WITH 6 FOOT SEAS. A COLD FRONT IS APPROACHING DEEP SOUTH TEXAS AND SHOULD CAUSE THE GRADIENT OVER THE COASTAL WATERS TO RELAX. THE WINDS ARE ALREADY BELOW SMALL CRAFT ADVISORY FOR BOTH THE LAGUNA AND THE GULF. THEREFORE WILL LOWER FLAGS FOR TONIGHT. WILL CONTINUE SMALL CRAFT SHOULD EXERCISE CAUTION FOR BOTH THE LAGUNA AND THE GULF FOR TONIGHT. THE COLD FRONT SHOULD MOVE THROUGH THE AREA BY SATURDAY AFTERNOON CAUSING SOME SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP AHEAD OF THE FRONT. A MODERATE TO STRONG NORTH WIND IN THE WAKE OF THE FRONT SATURDAY NIGHT COULD CAUSE SMALL CRAFT ADVISORY CONDITIONS. WINDS SHOULD GRADUALLY DECREASE SUNDAY THROUGH MONDAY AS HIGH PRESSURE BUILDS INTO THE AREA. A RETURN SOUTHEASTERLY FLOW OF AIR WILL DOMINATE THE AREA BY TUESDAY AS HIGH PRESSURE SLIDES EAST OVER THE GULF. .AVIATION...WINDS WILL BE QUITE GUSTY FROM THE SOUTH THIS AFTERNOON BEFORE DECREASING THIS EVENING AS THE WIND DECOUPLES. THERE IS A POSSIBILITY OF SHOWERS OR THUNDERSTORMS AFTER MIDNIGHT TONIGHT AS THE FRONT APPROACHES DEEP SOUTH TEXAS. THE FRONT SHOULD MOVE THROUGH THE AREA BY LATE MORNING WESTERN PORTION OF DEEP SOUTH TEXAS TO EARLY AFTERNOON EASTERN PORTION. WINDS WILL SWITCH FROM THE NORTHWEST AFTER FRONTAL PASSAGE ON SATURDAY. PRELIMINARY NUMBERS FOR COORDINATION PURPOSES ONLY... BRO EB 066/082 056/065 045 30/20/00/00/00 HRL EB 064/082 054/065 043 30/20/00/00/00 MFE EB 065/083 053/067 042 30/20/00/00/00 RGC EB 063/076 050/067 041 30/20/00/00/00 SPI EB 067/079 057/063 050 30/20/00/00/00 .BRO...NONE. 59/65 THIS PRODUCT IS ALSO AVAILABLE ON OUR INTERNET WEB PAGE AT: HTTP://WWW.SRH.NOAA.GOV/BRO tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 402 PM CST FRI FEB 14 2003 SNOW AND TEMPERATURES TONIGHT...AND CLOUD COVER SATURDAY AND SATURDAY NIGHT ARE THE PRIMARY FORECAST CONCERNS WITH THIS FORECAST PACKAGE. THE 14/12Z ETA MODEL IS UNDOING THE SURFACE DEW POINTS ACROSS IOWA...NEBRASKA...AND SOUTH DAKOTA BY 3F TO 5F. OTHER INITIALIZATION CONCERNS WERE THE 850 MB TEMPERATURES ON BOTH THE GFS AND ETA. THEY WERE INITIALIZED A COUPLE OF DEGREES TOO COLD. THIS IS LIKELY THE REASON WHY THE PRECIPITATION IS CURRENTLY FALLING AS RAIN INSTEAD OF FREEZING RAIN ACROSS NEBRASKA AND PORTIONS OF EAST CENTRAL IOWA. IN ADDITION...BOTH MODELS WERE UNDERESTIMATING THE STRENGTH OF THE UPPER LEVEL SHORT WAVE TROUGH WHICH IS CURRENTLY EXITING OUT OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY. THE PROFILERS CONTINUE TO SHOW MOISTURE MOVING UP INTO THE REGION AT 850 MB WHEN THEY WERE SUPPOSED TO BE ALREADY BRINGING IN DRIER AIR. AS A RESULT...THE 14/12Z MODELS ARE HAVING A HARD TIME WITH THE ONGOING PRECIPITATION. THIS WAS ESPECIALLY TRUE OF THE 14/12Z ETA AND MESO ETA. OVERALL...THE 14/12Z GFS IS DOING THE BEST WITH CURRENT LOCATIONS OF THE PRECIPITATION. A QUICK LOOK AT THE 14/18Z MESO ETA AND RUC MODELS SHOW A SIMILAR PRECIPITATION FIELD. AS A RESULT...I WENT CLOSER TO THEM FOR THIS FORECAST PACKAGE. THE GFS SHOWS THAT AROUND A TENTH OF AN INCH WILL FALL ACROSS WEST CENTRAL WISCONSIN...ONE TO THREE TENTHS ACROSS SOUTHEAST MINNESOTA...AND TWO TO FOUR TENTHS ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN. WITH THESE AMOUNTS IN MIND...I WENT UP TO AN INCH OF SNOW IN WEST CENTRAL WISCONSIN...1 TO 3 INCHES IN SOUTHEAST MINNESOTA...AND 2 TO 4 INCHES ACROSS SOUTHWEST WISCONSIN AND NORTHEAST IOWA. THE 14/12Z GFS AND 14/18Z RUC AND MESO ETA SHOW THAT THE ISENTROPIC LIFT AND FRONTOGENETIC FORCING WHICH IS CURRENTLY LOCATED OVER THE AREA WILL SLIDE SOUTH OVERNIGHT. THIS IS IN RESPONSE TO A CANADIAN HIGH PRESSURE SYSTEM...WHICH WAS ALSO OVERESTIMATED BY ABOUT 10 MB AT THE SURFACE ON THE 14/12Z MODELS...BUILDING SOUTH ACROSS THE REGION. DUE TO THIS...I HAVE THE SNOW MAINLY FALL DURING THE EVENING ACROSS WEST CENTRAL WISCONSIN AND SOUTHEAST MINNESOTA...AND THROUGH MUCH OF THE NIGHT IN NORTHEAST IOWA AND SOUTHWEST WISCONSIN. THE UPPER LEVEL RIDGE DOES A VERY GOOD JOB AT PUSHING THE LOW AND MID LEVEL MOISTURE SOUTH TONIGHT. HOWEVER...THE UPPER LEVEL MOISTURE WILL REMAIN IN PLACE. THUS...KEPT SKIES EITHER MOSTLY CLOUDY OF CLOUDY OVERNIGHT. WITH THE CLOUD COVER...TEMPERATURE GUIDANCE APPEARS TO BE TOO COLD. AS A RESULT...I RAISED KEPT THE TEMPERATURES NEAR THE PREVIOUS FORECAST. THE UPPER LEVEL CLOUDS WILL REMAIN ACROSS THE AREA ON SATURDAY AND THROUGH MUCH OF SATURDAY NIGHT. THESE CLOUDS ARE ASSOCIATED WITH A WEAKENING 500 MB SHORT WAVE TROUGH EXITING OUT OF THE NORTH CENTRAL PLAINS. THE LIFT AND MOISTURE WITH THIS SYSTEM IS RATHER LIMITED... THUS...I WENT JUST WITH MOSTLY CLOUD FOR THIS TIME PERIOD. ON SUNDAY...AN UPPER LEVEL SHORT WAVE RIDGE WILL MOVE OVERHEAD. WITH THE SUBSIDENCE ASSOCIATED WITH THIS SYSTEM...SKIES WILL BE GENERALLY SUNNY. THE NEXT CHANCE OF SNOW WILL COME ON MONDAY NIGHT AS A WARM FRONT MOVES EAST THROUGH THE AREA. HOWEVER...THE MOISTURE AND LIFT IS RATHER LIMITED...THUS ONLY WENT WITH SLIGHT CHANCE OR CHANCE PRECIPITATION PROBABILITIES. .LSE...NONE. $$ BOYNE wi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE LA CROSSE WI 215 PM CST FRI FEB 14 2003 LATEST RADAR AND SURFACE OBSERVATIONS INDICATED SNOW SPREADING INTO SOUTHEAST MN AND NORTHEAST IOWA. DRY EASTERLY FLOW STILL IMPEDING EASTWARD PROGRESS OF PRECIPITATION INTO WI ZONES. LATEST GFS AND RUC VERIFYING MUCH BETTER THAN 12Z ETA WITH DEPICTION OF ISENTROPIC LIFT...AND THUS QPF. THE ISENTROPIC LIFT NOTED MOVES SOUTHWARD THROUGH THIS AFTERNOON AND EVENING AS COLDER AND DRIER AIR FILTERS IN WITH BUILDING HIGH PRESSURE. UPDATED ZONES WERE SENT AT 20Z...WHICH REFLECT LATEST PRECIPITATION TRENDS. AS A RESULT...EXPECTING 1 TO 2 INCH SNOW ACCUMULATIONS FROM PORTIONS OF SOUTHEAST MN INTO NORTHEAST IOWA THE REST OF THIS AFTERNOON. .LSE...NONE. $$ THOMPSON wi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE LA CROSSE WI 1125 AM CST FRI FEB 14 2003 SURFACE ANALYSIS SHOWED LOW PRESSURE OVER THE TEXAS/OKLAHOMA PANHANDLE...WHILE HIGH PRESSURE CONTINUES BUILDING ACROSS SOUTHERN CANADA. REGIONAL RADAR INDICATED SNOW ADVANCING OVER SOUTHWEST MN... WITH A MIX OF FREEZING RAIN AND SNOW IN NORTHWEST IOWA. DRY EASTERLY FLOW IMPEDING EASTWARD PROGRESS OF PRECIPITATION. LATEST RUC AS WELL AS 12Z ETA INDICATED PRECIPITATION WILL BE SLOWER WITH ONSET INTO OUR FORECAST AREA. THUS...EASTWARD AND NORTHWARD EXTENT WILL BE DELAYED AND IN SOME AREAS NOT OCCUR AT ALL THIS AFTERNOON AND TONIGHT. THIS SUPPORTED BY BEST Q-G CONVERGENCE CONFINED TO SOUTHERN FRINGES OF OUR FORECAST AREA AND POINTS SOUTHWARD. IN ADDITION...850-700MB AND 700-650MB LAYER FN VECTORS SUPPORTED MAIN FORCING ASSOCIATED WITH FRONTOGENESIS ALSO FOCUSED TO THE SOUTH OF OUR FORECAST AREA. UPDATED ZONES WERE SENT AT 1705Z...WHICH SCALED BACK OR ELIMINATED SNOW CHANCES FROM ROCHESTER AREA THROUGH LA CROSSE AREA AND INTO SOUTHWEST WI. LIGHT SNOW STILL APPEARS LIKELY FOR NORTHEAST IOWA AND LOCATIONS NEAR THE MINNESOTA/IOWA BORDER CLOSER TO AUSTIN MN THIS AFTERNOON...BUT TRIMMED BACK ON AMOUNTS DUE TO SLOWER ONSET. .LSE...NONE. $$ THOMPSON wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FORT WORTH TX 410 AM CST SAT FEB 15 2003 SURFACE COLD FRONT...PER LATEST SURFACE OBS AND SPLIT CHANNEL SATELLITE IMAGERY...IS CURRENTLY APPROACHING NORTHWEST COUNTIES IN THE CWA. REFLECTIVITY DATA FROM KFWS HAS SHOWN WEAK CONVECTION FLARING UP SPORADICALLY THROUGHOUT THE NIGHT...AND EXPECT THIS TO CONTINUE AHEAD OF THE COLD FRONT. SHORT TERM GUIDANCE FROM THE ETA AND RUC40 SUGGESTS THAT PRESSURE GRADIENT WILL STRENGTHEN SUFFICIENTLY THROUGHOUT THE DAY TO WARRANT 20-30 MPH NORTH WIND SPEEDS...PROMPTING THE ISSUANCE OF A WIND ADVISORY FOR ALL OF NORTH TEXAS. COLD FRONT SHOULD MOVE RAPIDLY ACROSS THE AREA THIS MORNING ...AND EXIT SOUTHEAST ZONES BY AROUND NOON. AS A RESULT...HAVE OPTED TO NOT INCLUDE MENTION OF SEVERE THUNDERSTORMS. STEADY OR SLOWLY FALLING TEMPERATURES CAN BE EXPECTED LATER TODAY...AS STRONG COLD ADVECTION AND LOW CLOUDS WILL KEEP TEMPERATURES FROM RISING BEHIND FROPA. SLOW CLEARING IS EXPECTED OVERNIGHT...WITH A MOSTLY SUNNY DAY EXPECTED ON SUNDAY. WILL GO SLIGHTLY ABOVE GUIDANCE FOR HIGHS ON SUNDAY...WITH NEUTRAL TEMPERATURE ADVECTION AND MODERATE INSOLATION. A LIGHT FREEZE IS ANTICIPATED ACROSS ALL OF NORTH TEXAS ON MONDAY MORNING...GIVEN CLOSE PROXIMITY OF SURFACE HIGH AND OPTIMAL RADIATIONAL COOLING CONDITIONS. NO MAJOR CHANGES WERE MADE TO EXTENDED PORTION OF THE FORECAST. MEDIUM RANGE GUIDANCE IS CONSISTENT ON MOVING A WEAK SHORTWAVE TROUGH NORTH OF TEXAS ON WEDNESDAY...WITH SLIGHT CHANCE TO LOW CHANCE POPS FORECASTED FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. MAIN FORCING FOR UVV WILL COME FROM THE COLD FRONT...IN AN EVENT SIMILAR TO THAT OF TODAY. BY THE END OF THE WEEK...MRF AND CANADIAN MODELS ARE HINTING AT A STRONGER SURGE OF ARCTIC AIR INTO THE CENTRAL PLAINS. HOWEVER...THERE ARE SUFFICIENT DISCREPANCIES IN THE GUIDANCE TO FORECAST A MAJOR ARCTIC FRONTAL PASSAGE THIS FAR OUT. WILL SLIGHTLY COOL TEMPERATURES ON FRIDAY...AND REFINE FORECAST AS MORE GUIDANCE BECOMES AVAILABLE. DFW 54 33 49 30 / 30 0 0 0 ACT 66 34 50 31 / 30 0 0 0 PRX 60 30 47 27 / 30 0 0 0 DTO 52 31 48 28 / 20 0 0 0 TKI 55 31 48 28 / 30 0 0 0 DAL 55 32 49 29 / 30 0 0 0 TRL 60 32 49 29 / 30 0 0 0 CRS 67 34 50 31 / 30 0 0 0 TPL 70 34 51 31 / 30 0 0 0 .FWD... TX...WIND ADVISORY FOR TODAY FOR ZONES TXZ091>095...TXZ100>107... TXZ115>123...TXZ129>135...TXZ141>148...TXZ156>162...TXZ174>175. $$ 65/DD tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 945 AM EST SAT FEB 15 2003 CURRENTLY...HI PRES FROM THE SFC TO THE UPPER LEVELS WILL PROVIDE FOR A GENERALLY NICE WARM DAY ACROSS THE AREA. THE FLY IN THE OINTMENT IS PATCH OF MID AND HI CLOUDS OVER THE CENTER PORTION OF THE CWA. THIS HAS REDUCED THE EXPECTED WARM-UP A BIT. PUBLIC...MORNING RUC40 PICKS UP ON HIGHEST PORTION OF CLOUD DECK AT 400 MB. THE MODEL SHUNTS THE AREA OUT INTO THE ATLC BY 18Z. WILL INSERT "VARIABLE HIGH CLOUDINESS" WORDING INTO SOME OF THE ZONES. DON'T EXPECT MAX TEMPS TO BE AFFECTED TOO MUCH AND WILL GENERALLY LEAVE ALONE. WILL INDICATE A BIT OF COASTAL TEMP RANGE AND AFTN SEABREEZE DUE TO HIGH TEMP DIF BETWEEN THE LAND AND OCEAN. SEABREEZE SHOWS UP WELL ON 12KM ETA BY MID-AFTN. MARINE...WILL INDICATE SEABREEZE CIRCULATION IN NEAR SHORE SEGMENT. WILL ALSO KNOCK 1ST PERIOD SEAS DOWN ABOUT A FOOT. .JAX... FL...NONE. GA...NONE. CARROLL/BROYLES/DYKES fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 1120 AM EST SAT FEB 15 2003 .UPDATED...1100 AM SURFACE OBS INDICATE WINDS RUNNING AT 30 MPH AT FRENCHVILLE...23 MPH AT PRESQUE ISLE. RUC SURFACE/950 WINDS INDICATE THESE WINDS WILL PERSIST THIS AFTERNOON...SO WILL BUMP UP FORECAST WINDS TO 20 TO 30 MPH IN ZONES 1>4. EXPECT AFTERNOON CUMULUS TO BRING PARTLY CLOUDY SKIES THIS AFTERNOON NORTH...SUNNY ELSEWHERE. TEMPERATURES LOOK FINE. .SYNOPSIS...BITTERLY COLD ARCTIC AIR WILL CONTINUE TO FILTER INTO THE ENTIRE REGION THROUGH SUNDAY AS INTENSE LOW PRESSURE OVER THE CANADIAN MARITIMES MOVES SLOWLY EAST...AND HIGH PRESSURE GRADUALLY BUILDS EAST FROM SOUTH CENTRAL CANADA. A MODERATION IN TEMPERATURES IS EXPECTED ON MONDAY AS ARCTIC AIR BEGINS TO RETREAT NORTHWARD INTO CANADA. DISCUSSION... ARCTIC EXPRESS CONTINUES FOR AT LEAST ANOTHER 36 TO 48 HRS. I WILL BE USING THE ETA THRU THE 1ST 48 HRS BASED ON IT/S PERFORMANCE W/UA & SATL WV/IR TRENDS. TODAY...BASED ON LATEST ANAL & GUID...WILL KEEP WIND CHILL WARNINGS/ADVISORIES WHERE THEY AREA SITUATED. SHEARED VORT MAX SWINGING ACROSS THE REGION WILL IGNITE WINDS AGAIN W/CONTINUATION OF FRIGID AIR. ETA T1 VALUES WILL BE A BASIS FOR MAXES. WILL HAVE TO CARRY SOME CLOUDS FOR THE N AS H8 RH STILL THERE. WILL GROUP ZONE 2 W/1,3 &4 BASED ON THIS THINKING. TONIGHT...ANY CLOUDS SHOULD LEAVE BY SUNSET W/ANOTHER BRUTALLY COLD NIGHT. WILL ONCE AGAIN HAVE TO DEAL W/SOME GRADIENT DUE TO ARCTIC HIGH PRES STARTING TO SLIDE SE TOWARD THE CWFA & SFC LOW PRES MOVG NE OFF MID-ATLC COAST. ALTHOUGH...WINDS WILL NOT BE AS STG AS PRVS NIGHTS. WE/LL SEE SOME OF THE COLDEST TEMPS OF THE SEASON BY SUN MRNG. WILL NEED TO CARRY WIND CHILL WARNINGS FOR @ LEAST THE EVNG FOR THE N & ADVS FOR DOWNEAST & COAST. MINS WILL BE A REFLECTION OF THE ETA T1 ONCE AGAIN. SUNDAY...ARCTIC HIGH PRES STARTS TO SLIDES EVER SO CLOSER TO THE CWFA W/A RELAXATION IN THE GRADIENT...FINALLY!!. TEMPS WILL WARM TO ABOVE 0F ACROSS THE N FOR THE 1ST TIME IN 3 DAYS!. TEMPS WILL BE A BLEND OF THE MOS. LOOKING INTO SUNDAY NIGHT...WAA BEGINS TO TAKE EFFECT ALF. ARCTIC AIRMASS STILL ENTRENCHED OVER THE CWFA. DEEP SNOWPACK...DECENT RADIATIONAL COOLING PLUS ARCTIC AIR WILL ALLOW MINS TO BE MUCH COLDER THAN WHAT GUID IS PREACHING. THIS WILL DEPEND ON HOW MUCH CI GETS INTO THE REGION AHEAD OF THE WAA. EXPERIENCE HAS SHOWN THAT TEMPS-REALLY BOTTOM OUT AS INITIAL START OF WAA W/A COLD AIRMASS STILL ENTRENCHED. WILL TWEAK MINS DOWN A TAD ESP FOR 1ST 2 SET OF ZONE GROUPINGS. GOING FURTHER OUT: NO CHGS TO BE MADE. SFC LOW PRES SYSM MOVG NE FROM THE SERN U.S. WILL NEED TO BE WATCHED. ECMWF/CAN GLOBAL SHOW SYSM TO BE A BIT FURTHER W THAN GFS/UKMET W/SIGNIFICANT PRECIP ARRIVING INTO DOWNEAST & COAST MONDAY NIGHT INTO TUESDAY. DAYCREW HAS MENTION OF SNOW IN FOR LATE TUESDAY. DO AGREE THAT DENSE COLD AIR WILL BE HARD TO DISLODGE...HOWEVER...POSN OF ARCTIC HIGH PRES COULD BE A KEY PLAYER. THINGS MIGHT NEED TO BE MOVED UP INTO MONDAY NIGHT TIME FRAME IF CAN GLOBAL/ECMWF PAN OUT. DAYCREW CAN ASSESS THIS FURTHER. COASTAL WATERS...LOOKS LIKE GRADIENT RELAXES A TAD TODAY W/CONDS DOWN TO STG SCA LEVELS. WILL MOST LIKELY NEED GLW FOR TONIGHT AS VORT MAX SWINGS THROUGH THE WATERS W/ANOTHER DOSE OF CAA. GRADIENT LOOSENS UP ON SUN AS ARCTIC HIGH PRES BEGINS TO MOVE TOWARD THE AREA. .CAR...WIND CHILL WARNING ZONES 1>6/10 TODAY INTO TONIGHT. WIND CHILL ADVISORY ZONES 11/15>17/29>32 TODAY INTO TONIGHT. SCA FOR TODAY. GLW FOR TONIGHT. HEAVY FREEZING SPRAY TODAY THROUGH SUNDAY. APFFEL me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1035 AM EST SAT FEB 15 2003 12Z RAOBS/WV LOOP AND RUC ANLSYS SHOW CONTD SPLIT FLOW ACRS NAMERICA WITH UPR GRT LKS UNDER INFLUENCE OF NRN BRANCH NW FLOW BTWN RDG OVR WRN CAN AND SLOWLY DEPARTING ARCTIC VORTEX OVR ERN CAN. 1042MB SFC HI NOTED NR LK WINNIPEG WITH RDGING E ACRS ONTARIO. VERY COLD/DRY AIRMASS IS IN PLACE THERE...TEMPS IN ONTARIO JUST N OF LK SUP BLO -40 WITH DWPTS GENERALLY -25F TO -45F. 12Z INL/YPL SDNGS SHOW VERY DRY LLVLS WITH SHARP INVRNS ARND H925. 12Z GRB SDNG SHOWS A BIT MORE LLVL MSTR BLO INVRN ARND H9...NNE FLOW E OF HI PRES IN SCNTRL CAN HAS ADVCTD LK SUP MODERATED AIRMASS INTO CNTRL CWA WHERE CLDS/ FLURRIES RPRTD ATTM AS FAR INLAND AS IMT-ESC PER SFC OBS/88D/SAT PIX. THIS CLD...WHICH IS MOST EXTENSIVE OVR GENERALLY ICE-FREE SCNTRL LK SUP...TENDING TO DRIFT SW IN LLVL NE FLOW. 88D INDICATES REFLECTIVITIES IN WEAK LES BANDS COMING ASHORE IN MQT COUNTY NO GREATER THAN 12-15DBZ. EXTENSIVE ICE COVER ON LK SUP...UPSTREAM DRY AIR AS WELL AS HI STABILITY...AND GENERAL ACYC FLOW ARND HI ALL CONTRIBUTING TO MORE DISORGANIZED/WEAKER LES THAN ONE WOULD XCPT GIVEN H85 TEMPS -16C TO -20C. GENERALLY JUST SCT CLD ACRS WRN LK SUP. ERN ZNS MCLR AS NE FLOW OF DRY AIR DOWNSLOPING OFF ONTARIO NEAR ANJ HAS DSPTD CLD. KEWEENAW PENINSULA ALSO MCLR. MAIN FCST CONCERNS TDAY ARE CLD/WEAK LES TRENDS AND TEMPS. 12Z RUC SHOWS SLOWLY RISING H5 HGTS IN CONTD NW FLOW ALF AS VORTEX IN ERN CAN SLOWLY EDGES E. SFC HI PRES RDG FCST TO DRIFT SLOWLY E AS WELL WITH LLVL WND FLOW PROGGED TO SLOWLY VEER DURG DAY. RUC H95 RH DEPICTS PRESENT LK SC QUITE WELL AND SHOWS HIER RH UNDER INVRN TENDING TO DRIFT SW DURG DAY. VEERING WND FCST TO PUSH DRIER AIR OVR THE ERN ZNS W DURG DAY AS WELL. SO XPCT DCRSG CLDS IN ALGER/DELTA/ MNM COUNIES...BUT CONTD CLD COVER OR INCRSG CLDS IN BARAGA/MQT/IRON/ DICKINSON COUNTIES...WITH SOME BRK UP LATER TDAY AS RUC FCST SDNGS SHOW INVRN SUBSIDING TO H95 LVL. KEWEENAW SHUD REMAIN PCLDY WHILE NE TO E FLOW WL TEND TO DSPT SC DRIFTING AND DOWNSLOPING INTO GOGEBIC/ ONTONAGON ZNS. XPCT ANY SN ACCUMULATION LESS THAN AN INCH PER 88D OBS AND LWRG INVRN. MIXING TO H925-95 ON RUC FCST SDNGS SUG MAX WL RISE TO 10 TO 15...SO NO CHGS NECESSARY TO GOING FCST XCPT TO LWR FCST MAX OVR THE SCNTRL WHERE ENE FLOW WL ADVCT RELATIVELY UNMODIFIED ARCTIC AIR IN FM THE ERN ZNS. AFDMQT FM MIDNGT SHIFT FOR LATER PDS... TONIGHT HAS MAKINGS OF VERY COLD NIGHT W/ WEAK (AND OFFSHORE) GRADIENT AND DRY AMS IN PLACE. TEMPS JUST NORTH OF SUPERIOR ARE WELL INTO MINUS 30S. THOUGH WE WON'T GET THAT COLD...AT LEAST 20F BELOW LOOKS LIKE A GOOD BET INLAND AND EAST AS WE WILL TAP INTO THE EXTREMELY DRY AIR IN ONTARIO. HAVE GONE MUCH BELOW GUIDANCE HERE... BUT MAY NOT QUITE REACH RECORD OF -25F AT KMQT. SUNDAY WILL BEGIN TRANSITION TO MORE SERIOUS MODERATION...AS H8 TEMPS WARM TO -8C (PER ETA AND AVN) IN INCREASING S/SW FLOW. AGREE W/ PREVIOUS SHIFT THAT GUIDANCE MAY BE A LITTLE WARM (ESPECIALLY THE MET)...CONSIDERING HOW COLD WE WILL START THE DAY AT AND EXPECTED STRENGTH OF LLVL INVERSION. EVEN SO...SHOULD REACH INVOF 20F W/ LOTS OF SUN. ALSO AGREE W/ PREVIOUS SHIFT THAT MON HAS POTENTIAL TO BE VERY WARM DAY...W/ DRY AMS PERSISTING AND WAA KICKING H8 TEMPS TO NEAR ZERO OR A LITTLE ABOVE (PER ETA...AVN HAS COLD BIAS AND IS ABOUT 5C COOLER). NEW MAV GUIDANCE LOOKS ON TRACK THOUGH W/ HIGHS INTO 30S...MID 30S IN WEST. HAVE UPPED TEMPS IN GRIDS SLIGHTLY TO ACCOUNT FOR THIS. OTHERWISE NEW MODELS COMING IN AGREE IN KEEPING ANY MENTION OF PCPN OUT UNTIL MON EVENING IN WEST. U P WILL REMAIN IN DRY ANTICYCLONIC FLOW UNTIL THEN...AS LOW PRES DEVELOPS IN THE HIGH PLAINS. NO CHANGES TO THE EXTENDED. .MQT...HEAVY FREEZING SPRAY WRNG LAKE SUPERIOR. KC mi SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1026 AM EST SAT FEB 15 2003 COLD AND DRY NORTHEASTERLY WINDS ASSOCIATED WITH A 1040MB HIGH JUST NORTH OF LAKE SUPERIOR WILL PERSIST OVER THE LOWER LAKES REGION THROUGH THE AFTERNOON. KDTX RADAR IS SHOWING SOME LIGHT SNOW SHOWERS AND FLURRIES EXTENDING FROM THE THUMB INTO SOUTH-CENTRAL LOWER MICHIGAN. MOISTURE FLUX OFF LAKE HURON UNDER NORTHEASTERLY FLOW...WITH 925MB TEMPERATURES AROUND -20C HAS LED TO THE LAKE EFFECT ACTIVITY THIS MORNING. THE KDTX VAD WIND PROFILE SUGGESTS INVERSION HEIGHTS ARE NEAR 4K FT...NEARLY 2KFT HIGHER THAN EARLIER MODEL RUN SOUNDINGS SUGGESTED THEY WOULD BE. THE CURRENT RUC SOUNDINGS SEEM TO HAVE THE BEST HANDLE ON INVERSION HEIGHTS...ALTHOUGH IT ONLY SHOWS INVERSIONS AROUND 3K FT. THE RUC SOUNDINGS INDICATE MIXING WILL DRY OUT THE BOUNDARY LAYER THIS AFTERNOON. WITH PERSISTENT NORTHEAST FLOW OFF OF LAKE HURON THIS AFTERNOON AND WITH MODEL SOUNDINGS UNDERESTIMATING INVERSION HEIGHTS...I WILL CARRY THE MENTION OF FLURRIES NORTH OF M-59 THROUGH THE AFTERNOON. THE IR SATELLITE LOOP IS SHOWING PLENTY OF HIGH CLOUDS UPSTREAM. THERE HAS BEEN A WARMING TREND IN THE CLOUD TOPS...SO I DO EXPECT SOME BREAKS IN THE CLOUDS THIS AFTERNOON...ESPECIALLY ACROSS THE SAGINAW VALLEY. DUE TO THE EXTENT OF HIGH CLOUDS UPSTREAM AND WITH THE SCATTERED TO BROKEN STRATO CU DECK OVER THE CENTRAL PORTIONS OF THE FORECAST AREA...I WILL BE A BIT MORE PESSIMISTIC WITH CLOUD COVER THIS AFTERNOON. MAX TEMPERATURE FORECAST LOOKS ON TARGET. WITH PERSIST INFLUX OF ARCTIC AIR...I DO NOT EXPECT TEMPS TO RISE MUCH ABOVE CURRENT READINGS. .DTX...NONE. CONSIDINE EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1005 AM EST SAT FEB 15 2003 ...UPDATED TO PUT LAKE HURON LAKE EFFECT FLURRIES IN ZONES... LOOKING AT THE SATELLITE...RADAR MOSAIC OF THE WESTERN GREAT LAKES...AND SURFACE OBSERVATIONS IT IS APPARENT THAT LAKE EFFECT SNOW SHOWERS HAVE DEVELOPED OVER LAKE HURON AND CONTINUE TO STREAK TO THE SOUTHWEST INTO EASTERN AND SOUTHERN 1/2 OF THE GRR CWA. RUC AND LAPS SOUNDINGS SHOW THE MOISTURE TO 900 MB. THE LATEST ETA DOES SHOW SOME MOISTURE THERE TOO (BETWEEN 1000 AND 900 MB). BOTH THE ETA AND RUC SHOW THIS MOISTURE MIXING OUT THIS AFTERNOON AS HEIGHTS CONTINUE TO RISE AS THE SURFACE HIGH HEADS EAST ACROSS SOUTHERN ONTARIO. THE AIR IN THE CLOUD LAYER IS COLD ENOUGH OF SNOWFLAKE FORMATION... AND WILL REMAIN SO. I DO EXPECT THE LOW CLOUDS AND FLURRIES TO GRADUALLY MIX OUT/END AS SURFACE HEATING MIXES OUT THE LOW LEVEL MOISTURE WITH THE DRY AIR ABOVE IT. MEANWHILE...AT UPPER LEVELS THERE IS A SERIES OF SHORTWAVES SEEN ON THE WATER VAPOR IMAGE THAT AREA MOSTLY MOVING EAST. ALSO WITH THAT THERE IS THE LEFT ENTRANCE REGION LIFT FROM THE NORTHERN STREAM JET...WHO'S CORE WILL BE OVER NEW ENGLAND BY THIS EVENING. THOSE THINGS WILL COMBINE TO KEEP THE MID AND HIGH CLOUDS FAIRLY THICK OVER THE SOUTHERN 2/3 OF THE CWA THIS AFTERNOON. BOTTOM LINE TO ALL OF THIS IS MORE CLOUDINESS THIS AFTERNOON AND WITH THAT LOWER AFTERNOON HIGH TEMPERATURES. I ALSO PUT FLURRIES IN THE FORECAST FOR AREAS EAST AND SOUTH OF GRR (DUE TO NE WIND TRAJECTORIES OFF LAKE HURON AS SEEN ON THE GRR AND DTX 88D). .GRR...NONE. WDM mi AREA FORECAST DISCUSSION...UPDATED FOR AVIATION NATIONAL WEATHER SERVICE FORT WORTH TX 454 AM CST SAT FEB 15 2003 .AVIATION DISCUSSION... MVFR TO IFR EXPECTED THE NEXT SEVERAL HOURS AS LOW CLOUDS NORTH OF THE FRONT ARE LIFTED AND THEN REPLACED BY LOW CLOUDS AND GUSTY NORTH FLOW BEHIND THE FRONT. FRONT SHOULD BE THROUGH METRO AIRPORTS BY TAF ISSUANCE SO WILL START OFF WITH NW-N FLOW. 88D SHOWS SOME SHRA AROUND IN ADVANCE OF FRONT AND BEHIND IT AS WELL...BUT COVERAGE NOT REALLY A LOT. WILL WAIT UNTIL LAST MINUTE BEFORE MENTIONING ANY SHRA. LOW CLOUDS SHOULD LIFT IN THE AFTERNOON HOURS AS STAY VFR WITH STRONG N-NW FLOW AGAIN TONIGHT. .PUBLIC DISCUSSION... SURFACE COLD FRONT...PER LATEST SURFACE OBS AND SPLIT CHANNEL SATELLITE IMAGERY...IS CURRENTLY APPROACHING NORTHWEST COUNTIES IN THE CWA. REFLECTIVITY DATA FROM KFWS HAS SHOWN WEAK CONVECTION FLARING UP SPORADICALLY THROUGHOUT THE NIGHT...AND EXPECT THIS TO CONTINUE AHEAD OF THE COLD FRONT. SHORT TERM GUIDANCE FROM THE ETA AND RUC40 SUGGESTS THAT PRESSURE GRADIENT WILL STRENGTHEN SUFFICIENTLY THROUGHOUT THE DAY TO WARRANT 20-30 MPH NORTH WIND SPEEDS...PROMPTING THE ISSUANCE OF A WIND ADVISORY FOR ALL OF NORTH TEXAS. COLD FRONT SHOULD MOVE RAPIDLY ACROSS THE AREA THIS MORNING ...AND EXIT SOUTHEAST ZONES BY AROUND NOON. AS A RESULT...HAVE OPTED TO NOT INCLUDE MENTION OF SEVERE THUNDERSTORMS. STEADY OR SLOWLY FALLING TEMPERATURES CAN BE EXPECTED LATER TODAY...AS STRONG COLD ADVECTION AND LOW CLOUDS WILL KEEP TEMPERATURES FROM RISING BEHIND FROPA. SLOW CLEARING IS EXPECTED OVERNIGHT...WITH A MOSTLY SUNNY DAY EXPECTED ON SUNDAY. WILL GO SLIGHTLY ABOVE GUIDANCE FOR HIGHS ON SUNDAY...WITH NEUTRAL TEMPERATURE ADVECTION AND MODERATE INSOLATION. A LIGHT FREEZE IS ANTICIPATED ACROSS ALL OF NORTH TEXAS ON MONDAY MORNING...GIVEN CLOSE PROXIMITY OF SURFACE HIGH AND OPTIMAL RADIATIONAL COOLING CONDITIONS. NO MAJOR CHANGES WERE MADE TO EXTENDED PORTION OF THE FORECAST. MEDIUM RANGE GUIDANCE IS CONSISTENT ON MOVING A WEAK SHORTWAVE TROUGH NORTH OF TEXAS ON WEDNESDAY...WITH SLIGHT CHANCE TO LOW CHANCE POPS FORECASTED FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. MAIN FORCING FOR UVV WILL COME FROM THE COLD FRONT...IN AN EVENT SIMILAR TO THAT OF TODAY. BY THE END OF THE WEEK...MRF AND CANADIAN MODELS ARE HINTING AT A STRONGER SURGE OF ARCTIC AIR INTO THE CENTRAL PLAINS. HOWEVER...THERE ARE SUFFICIENT DISCREPANCIES IN THE GUIDANCE TO FORECAST A MAJOR ARCTIC FRONTAL PASSAGE THIS FAR OUT. WILL SLIGHTLY COOL TEMPERATURES ON FRIDAY...AND REFINE FORECAST AS MORE GUIDANCE BECOMES AVAILABLE. DFW 54 33 49 30 / 30 0 0 0 ACT 66 34 50 31 / 30 0 0 0 PRX 60 30 47 27 / 30 0 0 0 DTO 52 31 48 28 / 20 0 0 0 TKI 55 31 48 28 / 30 0 0 0 DAL 55 32 49 29 / 30 0 0 0 TRL 60 32 49 29 / 30 0 0 0 CRS 67 34 50 31 / 30 0 0 0 TPL 70 34 51 31 / 30 0 0 0 .FWD... TX...WIND ADVISORY FOR TODAY FOR ZONES TXZ091>095...TXZ100>107... TXZ115>123...TXZ129>135...TXZ141>148...TXZ156>162...TXZ174>175. $$ 65/DD tx EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WASHINGTON 230 AM PST SAT FEB 15 2003 .SYNOPSIS...A WEAK RIDGE OF HIGH PRESSURE WILL GIVE THE INLAND NORTHWEST A BRIEF PERIOD OF DRY WEATHER TODAY. THE WEATHER WILL THEN TURN INCREASINGLY WET TONIGHT AS A MOIST UPPER LEVEL TROF HEADS INLAND. THIS TROF WILL BRING A SERIES OF WEATHER SYSTEMS OVER THE AREA THROUGH MONDAY... EACH RESULTING IN A GOOD CHANCE OF PRECIPITATION. SNOW LEVELS WILL FALL SIGNIFICANTLY BY SUNDAY AFTERNOON AND MONDAY...POSSIBLY BRINGING SNOW SHOWERS TO SOME VALLEY LOCATIONS. .DISCUSSION...TODAY...SHORTWAVE RIDGE WILL CONTINUE TO RESIDE OVER THE INLAND NW TODAY...AS OFFSHORE TROF CONTINUES TO DIG THIS MORNING NEAR 35/140. THIS DIGGING HAS HELD UP THE EASTWARD PROGRESSION OF THE PRECIPITABLE WATER PLUME OFF THE COAST WHICH CONSEQUENTLY HAS DELAYED THE ONSET OF PRECIPITATION ONTO THE COAST. AS OF 10Z THERE STILL HAVE BEEN NO MEASURABLE REPORTS OF PRECIPITATION ON THE COAST. THIS SUGGEST THE 00Z GFS RUN WAS TOO AGGRESSIVE IN SPREADING THE PRECIPITATION INLAND THIS MORNING... AND SUPPORTS THE MORE CONSERVATIVE 00Z ETA AND 06Z MESOETA RUNS. THE RUC SUGGESTS THAT EVEN THESE RUNS ARE A BIT TOO FAST. THIS BEING SAID...WE WILL TRIM ALL POPS ACCORDINGLY TODAY...ESPECAILLY THOSE IN THE EASTERN ZONES. THE RIDGE AXIS IS EXPECTED TO MOVE INTO WESTERN MONTANA THIS AFTERNOON...WHICH IN TURN STRENGTHENS THE LOW- LEVEL FLOW OUT OF THE SOUTH. THIS RESULTS IN STRONG LOW-LEVEL WARM AIR ADVECTION AND DECENT MIXING FOR MOST LOCATIONS...AND SHOULD RESULT IN SIGNIFICANT WARMING VERSUS YESTERDAY. THIS MIXING WILL ALSO LIKELY ERODE ANY STRATUS OVER THE COLUMBIA BASIN LATER TODAY. .TONIGHT THROUGH SUNDAY MORNING...THE OFFSHORE TROF CONTINUES TO MOVE SLOWLY TOWARD THE COAST OVERNIGHT PUSHING THE PRECIPITABLE WATER PLUME INLAND. DECENT ISENTROPIC ASCENT THEN BEGINS TO COINCIDE WITH THIS INFLUX OF MOISTURE FROM THE SW RESULTING IN A HIGH LIKELIHOOD OF PRECIPITATION FOR MOST ZONES. THE SMALLEST CHANCE OF POPS WILL BE RESERVED FOR THE SE ZONES DUE TO THE SW-NE ORIENTATION OF THE MOISTURE PLUME. SNOW LEVELS WILL REMAIN FAIRLY HIGH WITH THE WARM SECTOR FIRMLY ENTRENCHED OVER THE CWA. .SUNDAY AFTERNOON THROUGH MONDAY...THE UPPER LEVEL TROF SHIFTS INLAND...BRINGING A DROP IN SNOW LEVELS...A MARKED INCREASE IN POTENTIAL INSTABILITY AND A SHIFTING OF THE LOW-LEVEL WINDS TO THE SW. ALL THESE INGREDIENTS POINT TO A CLASSIC SHOWERY REGIME...WITH MOST OF THE ACTIVITY FOCUSING NEAR THE SW FACING SLOPES OF THE CASCADES...BLUES AND NE WA AND NORTH IDAHO MOUNTAINS. LOCAL SNOWFALL TOTALS COULD BE IMPRESSIVE AS WE REMAIN IN THIS UNSETTLED REGIME FOR OVER 36 HOURS...HOWEVER THE ETA EXTENSION AND MM5 INDICATE THAT EVEN THE MOUNTAINS WILL REMAIN BELOW HIGHLIGHT CRITERIA EXCEPT FOR A FEW LOCAL AREAS. FOR NOW WE WILL HOLD OFF ON HIGHLIGHTS BUT IT WILL NEED TO BE MONITORED. INLAND NW WHICH WILL GR .EXTENDED...TUE THROUGH FRI...NEW RUN OF THE LATEST GFS DIFFERENT WITH STRENGH...TIMING AND POSITION OF CLOSED LOW MOVING INTO THE DISTRICT NEXT WEEK COMPARED TO YESTERDAY'S AND THURSDAY'S RUN. GFS QUITE DIFFERENT WITH THE EURO AND THE CANADIAN ALSO SO WE SEEM TO HAVE SOME MODEL UNCERTAINTY OVER THE EXTENDED PERIOD. WE WILL CONTINUE WITH THE CURRENT FORECAST AND NOT MAKE ANY CHANGES TO AVOID A FLIP-FLOP. THE DISTRICT WILL SEE A CHANCE OF MOUNTAIN SNOW EACH DAY WITH A SLIGHT CHANCE TO A CHANCE OF VALLEY RAIN AS WELL. ...THE INFORMATION IN THIS PRODUCT CONCERNING WARNINGS AND FORECASTS IS VALID ONLY AT THE TIME OF ISSUANCE. THE LATEST WARNING AND FORECAST INFORMATION WILL BE FOUND IN THE APPROPRIATE PRODUCTS... GEG 045/038/047/032/043 17756 COE 046/035/046/032/039 -7766 PUW 047/040/047/032/043 -7766 LWS 052/041/050/036/046 -6665 CQV 047/034/045/031/042 18746 SPT 044/033/045/031/040 19956 WWP 043/038/045/036/034 -8856 MWH 047/036/048/032/047 36635 EAT 044/034/048/032/044 46635 OMK 042/030/044/030/041 36646 .OTX...NONE. $$ wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 1145 AM EST SAT FEB 15 2003 HAVE OPTED TO UPDATE ZFP TO KILL WIND CHILL ADVISORY AND MAKE A FEW OTHER MINOR CHANGES TO THE GOING FCST. HI PRESS RIDGE TO CONT TO BUILD ACRS THE FA TODAY AND TONITE. 11-12Z 20KM "DEVELOPMENT" RUC SHOWS TEMPS TO GET UP INTO THE SINGLE NUMBERS (BOTH ABOVE AND BLO ZERO) TODAY WITH NORTHERLY SFC WINDS AT 5-15 KTS. T1MAX TEMPS ARE BASICALLY ZERO TO +10F TODAY AS WELL. FEW TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON THIS DATA AND CURRENT MESONET OBS. BASED ON EXPECTED MAX TEMPS AND MID-PT WIND SPEEDS TODAY...WILL ALLOW CURRENT WIND CHILL ADVISORY TO EXPIRE WITH THIS FCST PACKAGE. WILL CONT TO HIGHLITE SOME LOWER WIND CHILL VALUES FOR THE REST OF TODAY IN THE ZFP THOUGH. LOW-LVLS LOOK TO BE DRY ACRS THE FA TODAY AND TONITE. RUC SHOWS MAYBE SOME HIR CLDS AFFECTING THE SRN TIER ZONES TODAY. SAT PIX SHOW THAT SOME OF THESE CLDS MAY INDEED DO THIS TODAY. STRONG H85 CAA TO TAKE PLACE ACRS THE FA TODAY AND TONITE. MID-LVLS LOOKS TO BE DRY ACRS THE FA AS WELL TODAY AND TONITE. NO OTHER SIGNIFICANT WX EXPECTED ACRS THE FA OVER THE NEXT 24 HRS. FEW OTHER MOSTLY COSMETIC CHANGES TO GOING ZFP. WRK ZONES...FINAL ZFP...AND NPWBTV ALREADY ISSUED. LATER... .BTV...NONE. MURRAY vt