SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO 230 PM MDT SUN MAY 18 2003 SHORT TERM DISCUSSION...(TONIGHT AND MONDAY). ...MARGINAL FIRE WEATHER EVENT STILL POSSIBLE FOR PORTIONS OF S CNTRL CO THIS EVENING... CURRENTLY: LATEST WATER VAPOR IMAGERY/RUC MODEL UPPER AIR ANALYSES SHOWED RELATIVELY VIGOROUS MID/UPPER LEVEL FLOW OVER THE CENTRAL ROCKIES. ALSO...THERE IS AN ABUNDANCE OF MID/UPPER LEVEL MOISTURE(AOA H5) PER IR SATELLITE IMAGERY...WHICH MAY BE KEEPING THE WINDS "AT BAY" AND SFC RH FROM TUMBLING TOO LOW AS FEARED YDA. SO FAR...ANY LIGHTNING STRIKES WERE CONFINED WELL TO THE W-NW OF OUR CWA. RGNL/LOCAL RADAR DATA SHOWING SHOWERS DEVELOPING ACROSS THE WRN 1/2 OF CO. SFC TEMPS HAVE BEEN ON THE INCREASE TDA...BUT THE WIND AND PESKY DEW POINT FORECASTS HAVE BEEN TOUGH. GENERALLY...ACROSS S CNTRL CO...THE WIND HAS PICKED UP SIGNIFICANTLY SINCE THIS AM. ALS ALREADY BLOWING SW AROUND 20KTS SUSTAINED. BIG HORN RAWS(SW CORNER OF SAN LUIS VALLEY @ 8334 FT MSL)HAS BEEN CONSISTENTLY GUSTING AROUND 40 MPH. CUCHARA RAWS(SRN SANGRE DE CRISTO MTNS @ 8313 FT MSL) STARTING TO GET GUSTS IN THE 30S (MPH). SFC WINDS ALONG THE I-25 CORRIDOR AND SERN CO PLAINS HAVE BEEN A REAL CHALLENGE. WINDS ALREADY OUT OF THE N @ 3-15KTS AND MAY HAVE TO DO SOMETHING WITH THE VIRGA/SFC HEATING/TERRAIN AND NOT ENOUGH SYNOPTIC INFLUENCE...YET. DON'T THINK IT IS THE TRUE COLD FRONT...WHICH IS ANTICIPATED MOVING DOWN ERN CO LATER TNGT INTO MON. TNGT: W-SW FLOW STILL PROGGED ACROSS CO TNGT. STILL SOME MARGINAL FIRE WEATHER CONCERNS WITH RH...WIND...LONG TERM DROUGHT AND LIGHTNING EARLY THIS EVENING...SO WILL CONTINUE RED FLAG WARNING UNTIL 9PM TNGT. WILL CONTINUE WITH ISOLD-SCT PRECIPITATION WITH SOME HIGHER TERRAIN(AOA 10K FT MSL) SNOWFALL OUT NEAR THE CONTDVD. THE ISOLD-SCT CONVECTIVE PRECIP SHOULD EVOLVED INTO A POTENTIAL NOCTURNAL MCS ACROSS NERN CO/NWRN KS...AS A 40-50KT 850-800MB LLJ KICKS IN LATER TNGT. THIS WILL ALSO BE AROUND THE +10C TO +12C H7 "CAP." THIS SHOULD BRING IN A NICE OUTFLOW BOUNDARY OR HELP TRANSLATE THE COLD FRONT DOWN THE ERN CO HIGH PLAINS OVERNIGHT. ALL MODELS STILL INDICATING PRECIP CHANCES WILL ALMOST NIL OVERNIGHT...SO THERE MAY NOT BE MUCH AFTER MIDNIGHT. MON: A MUCH COOLER AND STABLE AIR MASS IS STILL ON TARGET FOR MON ACROSS THE SERN CO MTNS/PLAINS. MAX TEMPS SHOULD BE SOME 15-25 DEGREES COOLER THAN TDA IN THOSE AREAS AND WILL HEAVILY DEPEND ON THE EARLY MORNING STARTING TEMPS. THE CHALLENGE IS HOW FAR W WILL THE RELATIVELY SHALLOW COLD FRONT MAKE IT. CURRENTLY...MESO-ETA INDICATES THIS AIR MASS WILL NOT MAKE IT INTO THE SAN LUIS VALLEY AND TOWARDS THE CONTDVD. MODELS CONTINUING TO SUGGEST THAT PRECIP CHANCES WILL BE ABOUT NIL MON AM. NOT SURE HOW MUCH FOG THERE WILL BE WITH 10-25 MPH WINDS ALONG I-25 AND SERN CO PLAINS. PLAN TO REMOVE. FRONT SHOULD BE BANKED UP ALONG THE SERN CO MTNS WITH RELATIVELY STABLE AIR TO THE EAST AND UNSTABLE AIR TO THE WEST ACROSS THE SAN LUIS VALLEY AND CONTDVD. TEMPS WILL BE CERTAINLY A CHALLENGE. WILL NOT BUY INTO FALLING TEMPS IN SERN CO YET...THERE IS THE POTENTIAL FOR A FEW BREAKS IN THE CLOUDS AND THE MID MAY SUN COULD ALLOW FOR SOME TEMP RECOVERY MON AFTN. AS WITH THESE PATTERNS...IT WILL PROBABLY BE WARMER IN THE SAN LUIS VALLEY THAN ON THE PLAINS. FCST GRIDS REFLECT THIS WELL. WILL HAVE CHC POPS OUT NEAR THE CONTDVD WITH SHRA/TSRA POTENTIAL GIVEN THE INSTABILITY(LI 0C TO -4C/H7-H5 LAPSE RATES AROUND 9 C/KM AND CAPE 100-300 J/KG). MESO-ETA PROJECTING ITS QPF SWATH IN THIS AREA. FOR THE SERN CO MTNS/PLAINS...WILL GO WITH LOWER POPS AND JUST SHOWERS AS ANY STRONGER CONVECTION SHOULD HIT THIS MORE STABLE AIR MASS AND DIMINISH IN STRENGTH/COVERAGE. FOR THE SAN LUIS VALLEY MON AFTN...BUFKIT HI RES SOUNDING SHOWING AN INVERTED V SOUNDING WITH "DRY" MICROBURST POTENTIAL('VIRGA BOMBS'). LONG TERM DISCUSSION...(MONDAY NIGHT THROUGH NEXT SUNDAY). MONDAY NIGHT INTO TUESDAY SEES THE RETURN OF UPPER ZONAL FLOW WHILE THE SURFACE HIGH PUSHES INTO IOWA. THEN UPPER FLOW TRANSITIONS TO AN UPPER RIDGE OVER THE 4-CORNERS REGION FROM WEDNESDAY INTO THE UPCOMING HOLIDAY WEEKEND WITH A HEALTHY UPPER HIGH IN CONTROL OF THE 4-CORNERS BY NEXT SUNDAY. THE COMBINATION OF A THERMAL LOW OVER THE DESERT SOUTHWEST WITH A SURFACE HIGH IN THE VICINITY OF THE MIDWEST WILL ALLOW RELATIVELY PERSISTENT AND MOIST SOUTHEAST FLOW INTO THE CWFA FROM LATER WEDNESDAY INTO THE UPCOMING WEEKEND AND THIS COMBINED WITH THE STRONG DAILY HEATING CYCLE WILL ALLOW FOR THE POSSIBILITY OF AT LEAST ISOLATED MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS FROM LATER WEDNESDAY INTO THE WEEKEND. TEMPERATURES ON A DEFINITIVE WARMING TREND FROM WEDNESDAY INTO MEMORIAL WEEKEND WITH NEXT SUNDAY'S MAXIMUM TEMPERATURES PROJECTED TO BE QUITE TOASTY...I.E. HOVERING AROUND 90F FROM LOWER ELEVATIONS OF THE I-25 CORRIDOR AND POINTS EAST. .PUB...RED FLAG WARNING FOR FIRE WEATHER ZONES 220>225 BELOW 9000 FEET...UNTIL 9 PM MDT SUN. co SOUTHWEST IDAHO/SOUTHEAST OREGON AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE IDAHO 400 AM MDT SUN MAY 18 2003 ONLY A FEW ADJUSTMENTS TO CURRENT FORECAST. SECONDARY UPPER LOW NEAR UIL PER 00Z RAOBS WEAKENING INTO DEEP UPPER TROF OVER WA-ORE PER 09Z RUC WITH SATELLITE IMAGERY AND CLOUD PRODUCT/WR2 SHOWING SCT-BKN CLOUDS IN E-CENTRAL OREGON AND CENTRAL IDAHO AND ANOTHER PATCH ACROSS SW IDAHO. WITH COLD UPPER TROF MOVING OVER IDAHO TODAY EXPECT ANOTHER SURGE IN WINDS DEVELOPING BY NOON OVER BAKER AND LINGERING THRU EVENING ESPECIALLY IN THE MAGIC VALLEY. SFC PRES GRADIENT FCST SUPPORTS THIS. COLD AIR IN PLACE TONIGHT WITH CLEARING BY MIDNIGHT ALL BUT FAR SE ZONES WILL ALLOW STRONG RADIATIONAL COOLING RESULTING IN MOST STATIONS GETTING NEAR OR RECORD BUSTING COLD TONIGHT. ONE PROBLEM AREA MAY BE WESTERN MAGIC VLY WHERE A LOCALIZED HARD FREEZE IS POSSIBLE. THE WINDS WILL STAY UP LONGER AND CLOUDS LINGER LATER BUT BOTH ARE EXPECTED TO DECREASE LATE. SLIGHTLY HIGHER ELEVATION MEANS SLIGHTLY COLDER TOO SO LOWS 27-30 ARE FCST BUT MAY BE TOO COLD IF DEEP UPPER TROF IS SLOW TO EXIT. WARMING WITH DRY CONDITIONS ARE EXPECTED THROUGH THE WEEK AS A DIRTY UPPER RIDGE SLIPS UP OVER THE AREA EARLY THIS WEEK THEN BUILDS STRONGER THURSDAY-FRIDAY IN RESPONSE TO DEEPING OFFSHORE UPPER TROF ALONG 140W THURSDAY NIGHT. NUDGED TEMPS UP A BIT WITH WELL DEVELOPED THERMAL RIDGE OVER AREA THURSDAY-FRIDAY. RIDGE BREAKS DOWN NEXT WEEKEND ALLOWING A COLD FRONT THROUGH SW IDAHO SATURDAY. LEFT IN POPS AND SLIGHT CHC THUNDERSTORMS WITH THIS FEATURE WHICH THE NEW EXTENDED GFS... CONSISTENT WITH EARLIER RUNS...BRINGS THROUGH THE CWFA SATURDAY. .BOI...NONE. $$ = VJM id AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1115 AM CDT SUN MAY 18 2003 ZONES LOOK FINE TODAY AS MOSTLY CLOUDY SKIES PREVAIL THIS AFTERNOON EXCEPT PARTLY SUNNY AROUND PEORIA. PROB30 CHANCE OF SHOWERS FROM I-70 SOUTH. HIGHS IN THE MID TO UPPER 70S WITH WARMEST READINGS NEAR PEORIA WHERE MORE SUNSHINE POSSIBLE. WILL JUST MAKE MINOR UPDATES IN GRIDS TODAY FOR HOURLY WINDS...TEMPS AND DEWPOINTS. 579 DM 500 MB LOW WAS OVER NORTHERN MS AND CONTINUES TO GRADUALLY FILL IN WHILE DRIFTING SLOWLY SE. ASSOCIATED 1011 MB SURFACE LOW WAS JUST SE OF MEMPHIS. AN INVERTED TROF EXTEND NNE FROM THIS LOW ALONG I-57 ACROSS IL. JUST SOME SPOTTY DRIZZLE ACROSS CENTRAL AND SE ILX CWA THIS MORNING AND LOW CLOUDS STARTING TO BREAK UP AND LIFT A BIT ESPECIALLY AROUND PEORIA. LOWEST CEILINGS BETWEEN 500 AND 1000 FT ALONG I-72 IN CENTRAL IL. 11 AM TEMPS IN THE MID TO UPPER 60S WITH LOWER 70S FROM I-70 SOUTH. WINDS ARE EAST AT 8 TO 15 MPH. MODELS CONTINUE TO GRADUALLY FILL UPPER LEVEL LOW AS IT DRIFTS SLOWLY SE TOWARD THE SOUTHERN MS/AL BORDER THIS EVENING. SURFACE FLOW TO BECOME LESS CYCLONIC DURING THIS AFTERNOON AS SURFACE LOW ALSO WEAKENS. SO EXPECT TO SEE LESS SHOWERS AROUND TODAY AND A BIT MORE SUNSHINE POSSIBLE THIS AFTERNOON THAN WHAT OCCURRED SATURDAY. NORTHERN CWA CONTINUING TO HAVE MORE SUN AND MILDER TEMPS AS CURRENT FORECAST REFLECTS. THINK RUC AND MESOETA HIGHS IN THE UPPER 70S AND LOWER 80S TOO WARM THIS AFTERNOON GIVEN EXTENT OF LOW CLOUD COVER WITH BROKEN CEILINGS. .ILX...NONE. $$ HUETTL il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 1235 PM EST SUN MAY 18 2003 18Z TAF DISCUSSION... DELINEATION BETWEEN MVFR AND VFR CONDITIONS BETWEEN KFWA AND KSBN AND LIKELY TO REMAIN. RUC40 SOUNDINGS AT SBN SHOW CONTINUED DRYING/MIXING OF LAYER COUNTERING VERY SLOW NORTHWARD PROGRESSION OF DEEPER LOW LEVEL MOISTURE. STILL WITH COOLING OF TOP OF LAYER TONIGHT ANTICIPATE REFORMING OF MVFR CIGS AT SBN AND POSSIBLE LOWERING AT KFWA. CONVECTION AHEAD OF FRONT MONDAY WILL REMAIN WEST OF SBN THROUGH 18Z...MAY NEED TO BE INTRODUCED BY NEXT ROUTINE ISSUANCE. PBM PUBLIC DISCUSSION... SKY COVER AND TEMPERATURES WILL BE CONCERN TODAY...THEN TEMPERATURES AND PCPN CHANCES MONDAY AND TUESDAY. UPPER LOW CONTINUES TO SPIN AND MOVE SOUTH AS SEEN ON WATER VAPOR AND IR LOOPS. HIGH CLOUDS OVER AREA BEGINNING TO THIN AS CIRCULATION MOVES SOUTH. RECENT FOG PRODUCT IMAGERY AND OBSERVATIONS INDICATE LOW CLOUDS AND SOME FOG OVER SOUTHERN HALF OF CWFA THIS MORNING WHILE NORTHERN AREAS REMAIN CLEAR. SOME LIGHT RAIN SEEN JUST TO SOUTH OF AREA PER KIND/KILN 88DS. EXPECT WITH LIGHT WINDS AND ABUNDANT LOW LEVEL MOISTURE THAT FOG AND LOW CLOUDS WILL DEVELOP/SPREAD BACK INTO THE NORTH. WILL STICK WITH AREAS OF FOG AND BKN-OVC CLOUDS EARLY THIS MORNING ALL AREAS AND SOME SPRINKLES/DRIZZLE POSSIBLE SOUTH. EXPECT MOISTURE TO BE SHALLOW IN THE NORTH AND MAY SUN SHOULD MIX THESE CLOUDS OUT. HOWEVER...CU RULE INDICATES BKN CU SHOULD REFORM WITH THE MOISTURE THAT IS IN PLACE. IN THE SOUTH...DEEPER MOISTURE AND MORE MID AND HIGH CLOUDS WL KEEP MORE CLOUDS IN PLACE. WILL HAVE HIGHER AMOUNTS OF CLOUDS IN SOUTH. AFFECT ON TEMPS WILL BE WARMER NUMBERS NORTHWEST WITH MORE SUN. PATCHY FOG POSSIBLE AGAIN TONIGHT. ON MONDAY...HAVE DECIDED TO INTRODUCE LOW CHANCE OF AFTERNOON THUNDERSTORMS TO WESTERN HALF OF CWA. COLLABORATION WITH IND AND AGREE WITH INCREASE IN LOW LEVEL MOISTURE...AFTERNOON INSTABILITY AND FASTER APPROACH OF UPSTREAM COLD FRONT...COULD BE SOMETHING POP UP. BETTER CHANCE WITH FRONTAL PASSAGE MONDAY NIGHT AND TUESDAY MORNING. BEST UPPER FORCING MOVES NORTH WITH THIS SYSTEM BUT STRONG THERMODYNAMIC PROFILE AND LOW LEVEL CONVERGENCE WARRANTS HIGH CHC POPS FOR NOW. PRECIPITABLE WATER VALUES EXCEED 1.5 INCHES MONDAY AFTERNOON AND MONDAY NIGHT WHILE LIFTED INDICES GO TO ABOUT M2-M4. STRONG THUNDERSTORMS WITH HEAVY RAIN CERTAINLY POSSIBLE. AT THIS POINT...THINK SEVERE WILL BE MARGINAL GIVEN LACK OF STRONG UPPER DYNAMICS OVER AREA AND TIMING OF FRONT. HOWEVER...STRENGTH OF COLD FRONT...TEMPERATURE GRADIENT AND INSTABILITY SHOULD NOT BE OVERLOOKED. HAIL AND WIND GUSTS WOULD BE PRIMARY THREAT. NO SIGNIFICANT CHANGES TO EXTENDED PERIODS. .IWX... IN...NONE. MI...NONE. OH...NONE. LASHLEY/12 in AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE WICHITA KS 900 PM CDT SUN MAY 18 2003 MODELS SHOW MODEST ISENTROPIC UPGLIDE SETTING UP IN THE 305-315K LAYER OVER NW KS TONIGHT. THIS LIFT SHOULD PROVIDE AMPLE UPWARD VERTICAL MOTION FOR DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. THIS AREA OF UPGLIDE WILL MOVE INTO CENTRAL KS BY THE EARLY MORNING HRS AND SPREAD INTO S CENTRAL KS A BIT LATER ON. FOG CHANCES LOOK TO RESIDE MAINLY OVER SE KS TNGHT AS PREVIOUS SHIFT ELUDED TOO...OTHERWISE GOING FCST LOOKS TO BE RIGHT ON TRACK WITH ONLY MINOR TWEAKS TO GRIDS. FCSTID = 15/JAKUB -------------------------------------------------------------------- 300 PM CDT SUN MAY 18 2003 FCST FOCUS ON TIMING OF FRONT AND IMPACT ON TEMPS/PRECIP CHCS. LATEST WATER VAPOR LOOP SHOWS UNSEASONABLY COLD UPPER TROUGH ACROSS THE NORTHERN ROCKIES. AHEAD OF THIS TROUGH, SOUTHWESTERLY FLOW HAS DRAGGED WARM TEMPERATURES IN THE 800-700MB LAYER ACROSS THE AREA. LATEST RUC ANALYSIS SUGGESTS 700MB TEMPS IN THE +12 TO +14C RANGE MOVING ACROSS THE CWA TONIGHT. SURFACE PATTERN REMAINS INFLUENCED BY DEPARTING UPPER LOW. THIS HAS KEPT ORGANIZED SOUTH FLOW ACROSS THE HIGH PLAINS. THAT SAID, BOUNDARY LAYER MOISTURE REMAINS IN THE 60 TO 65F FOR SURFACE DEWPOINTS WITH 5 TO 10C 850MB DEWPOINTS. FOR TONIGHT, EXPECT PLENTY OF HIGH CLOUDS THAT SHOULD AID IN KEEPING MORE WIDESPREAD FOG FROM FORMING. PATCHY FOG SEEMS POSSIBLE AGAIN ACROSS THE SE GIVEN EXPECTED LIGHT SE 5 TO 10 MPH WIND AND LOW 60S DEWPOINTS. LATEST GFS/ETA ALSO SUGGEST CAPPING INVERSION DIMINISHING TOWARD 12Z AS THETA SFCS RISE BEHIND FRONT...WHICH IS NOW EXPECTED TO SURGE INTO/THROUGH CENTRAL KS BY 15Z. HAVE LEFT GOING TEMPS AS IS FOR HIGHS BUT EXPECT HIGHS TO OCCUR MIDDAY WITH FALLING TEMPS LIKELY BY LATE DAY. CONVECTION STILL APPEARS TO FIRE IMMEDIATELY ALONG AND BEHIND THE FRONT WITH LATEST INSTABILITY PROGS INDICATING 1000J/KG OF ELEVATED CAPE IMMEDIATELY BEHIND THE FRONT WITH UP TO 2500J/KG OF SFC BASED CAPE/NO CAP POSSIBLE AHEAD OF THE FRONT IF...IF TEMPS CAN REACH THE MIDDLE 80S...NO SO SURE THIS WILL HAPPEN...EVEN ACROSS THE SE. IN ANY EVENT, RISING THETA SFCS BEHIND THE FRONT SUGGEST PLENTY OF UPWARD MOTION FOR THUNDERSTORMS BY LATE DAY...ELEVATED SUPERCELLS NOT OUT OF THE QUESTION INITIALLY ACCORDING TO CONRAD/BUFKIT SOUNDING PROFILES. GREATER CHCS EAST OF ICT...THEN INTO OK WITHIN GREATEST 850-700MB THETA E AXIS. NORTH WINDS OF 25 TO 35 MPH THEN WILL OCCUR FROM 00Z-06Z TOMORROW NIGHT PUSHING ADVISORY CRITERIA. LINGERING PRECIP CHCS INTO EARLY TUES ACROSS THE SE LOOKS REASONABLE BEFORE A MAINLY DRY AND SEASONABLE PERIOD SETS IN THROUGH THE END OF THE WEEK. SOME POTENTIAL FOR UPSLOPE FLOW/NORTHWEST FLOW HYBRID REGIME TO SET UP HOWEVER AT THIS TIME IT APPEARS TO BE MORE FAVORABLE FOR PRECIP TO REMAIN ACROSS THE HIGH PLAINS...WEST OR NORTH OF THE CWA WITHIN 850-700MB THETA E RIDGE. FCSTID = 11 ICT 63 75 47 65 / 10 40 40 5 HUT 61 71 46 64 / 10 40 30 0 EWK 62 74 46 64 / 10 50 40 0 EQA 62 77 47 65 / 10 60 40 5 WLD 64 78 50 66 / 10 60 50 10 RSL 60 63 45 64 / 30 50 10 0 GBD 60 66 46 64 / 20 40 20 0 SLN 60 69 45 64 / 20 60 30 0 MPR 62 74 46 64 / 10 50 40 0 CFV 63 85 50 66 / 10 60 60 20 CNU 62 83 49 65 / 10 60 60 20 K88 62 82 48 65 / 10 60 50 20 .ICT...NONE. $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 300 PM CDT SUN MAY 18 2003 FCST FOCUS ON TIMING OF FRONT AND IMPACT ON TEMPS/PRECIP CHCS. LATEST WATER VAPOR LOOP SHOWS UNSEASONABLY COLD UPPER TROUGH ACROSS THE NORTHERN ROCKIES. AHEAD OF THIS TROUGH, SOUTHWESTERLY FLOW HAS DRAGGED WARM TEMPERATURES IN THE 800-700MB LAYER ACROSS THE AREA. LATEST RUC ANALYSIS SUGGESTS 700MB TEMPS IN THE +12 TO +14C RANGE MOVING ACROSS THE CWA TONIGHT. SURFACE PATTERN REMAINS INFLUENCED BY DEPARTING UPPER LOW. THIS HAS KEPT ORGANIZED SOUTH FLOW ACROSS THE HIGH PLAINS. THAT SAID, BOUNDARY LAYER MOISTURE REMAINS IN THE 60 TO 65F FOR SURFACE DEWPOINTS WITH 5 TO 10C 850MB DEWPOINTS. FOR TONIGHT, EXPECT PLENTY OF HIGH CLOUDS THAT SHOULD AID IN KEEPING MORE WIDESPREAD FOG FROM FORMING. PATCHY FOG SEEMS POSSIBLE AGAIN ACROSS THE SE GIVEN EXPECTED LIGHT SE 5 TO 10 MPH WIND AND LOW 60S DEWPOINTS. LATEST GFS/ETA ALSO SUGGEST CAPPING INVERSION DIMINISHING TOWARD 12Z AS THETA SFCS RISE BEHIND FRONT...WHICH IS NOW EXPECTED TO SURGE INTO/THROUGH CENTRAL KS BY 15Z. HAVE LEFT GOING TEMPS AS IS FOR HIGHS BUT EXPECT HIGHS TO OCCUR MIDDAY WITH FALLING TEMPS LIKELY BY LATE DAY. CONVECTION STILL APPEARS TO FIRE IMMEDIATELY ALONG AND BEHIND THE FRONT WITH LATEST INSTABILITY PROGS INDICATING 1000J/KG OF ELEVATED CAPE IMMEDIATELY BEHIND THE FRONT WITH UP TO 2500J/KG OF SFC BASED CAPE/NO CAP POSSIBLE AHEAD OF THE FRONT IF...IF TEMPS CAN REACH THE MIDDLE 80S...NO SO SURE THIS WILL HAPPEN...EVEN ACROSS THE SE. IN ANY EVENT, RISING THETA SFCS BEHIND THE FRONT SUGGEST PLENTY OF UPWARD MOTION FOR THUNDERSTORMS BY LATE DAY...ELEVATED SUPERCELLS NOT OUT OF THE QUESTION INITIALLY ACCORDING TO CONRAD/BUFKIT SOUNDING PROFILES. GREATER CHCS EAST OF ICT...THEN INTO OK WITHIN GREATEST 850-700MB THETA E AXIS. NORTH WINDS OF 25 TO 35 MPH THEN WILL OCCUR FROM 00Z-06Z TOMORROW NIGHT PUSHING ADVISORY CRITERIA. LINGERING PRECIP CHCS INTO EARLY TUES ACROSS THE SE LOOKS REASONABLE BEFORE A MAINLY DRY AND SEASONABLE PERIOD SETS IN THROUGH THE END OF THE WEEK. SOME POTENTIAL FOR UPSLOPE FLOW/NORTHWEST FLOW HYBRID REGIME TO SET UP HOWEVER AT THIS TIME IT APPEARS TO BE MORE FAVORABLE FOR PRECIP TO REMAIN ACROSS THE HIGH PLAINS...WEST OR NORTH OF THE CWA WITHIN 850-700MB THETA E RIDGE. FCSTID = 11 ICT 63 75 47 65 / 10 40 40 5 HUT 61 71 46 64 / 10 40 30 0 EWK 62 74 46 64 / 10 50 40 0 EQA 62 77 47 65 / 10 60 40 5 WLD 64 78 50 66 / 10 60 50 10 RSL 60 63 45 64 / 30 50 10 0 GBD 60 66 46 64 / 20 40 20 0 SLN 60 69 45 64 / 20 60 30 0 MPR 62 74 46 64 / 10 50 40 0 CFV 63 85 50 66 / 10 60 60 20 CNU 62 83 49 65 / 10 60 60 20 K88 62 82 48 65 / 10 60 50 20 .ICT...NONE. $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 347 PM EDT SUN MAY 18 2003 FORECAST CONCERNS ARE CHANCE OF SHOWERS AND THUNDERSTORM ON MONDAY. WATER VAPOR IMAGERY AND RUC/ETA SHOWING A CLOSED LOW SPINNING OVER LOUISIANA. A RIDGE DIVIDES THE CONUS BY STRETCHING NORTHEAST FROM A HIGH OVER MEXICO TO THE UPPER GREAT LAKES. A TROUGH IS DIGGING INTO THE NORTHERN ROCKIES. SHORTWAVE IMPULSE ARE BEING EJECTED OUT AHEAD OF IT PRODUCING SHOWERS AND THUNDERSTORMS OVER THE DAKOTAS TODAY. SURFACE ANALYSIS INDICATE A LOW OVER THE BLACK HILLS WITH A COLD FRONT EXTENDING NORTHEAST INTO EASTERN MANITOBA. THIS SYSTEM IS USHERING IN MOISTURE INTO THE UPPER MISSISSIPPI VALLEY AND INTO ONTARIO. MODEL IN A FAIRLY GOOD AGREEMENT IN THE TRACKING OF THE COLD FRONT THROUGH THE NORTHERN PLAINS AND THE GREAT LAKES DURING THE NEXT 48 HOURS. THE LOW OVER LOUISIANA WILL RELOCATE TO THE MISSISSIPPI DELTA TONIGHT. THE MID LEVEL RIDGE OVER THE UPPER GREAT LAKES WILL SLIDE INTO SOUTHEAST ONTARIO AND SOUTHERN QUEBEC. THE MID-LEVEL TROUGH OVER THE NORTHERN ROCKIES WILL MOVE INTO THE NORTHERN HIGH PLAINS. A SHORTWAVE BEING EJECTED OUT AHEAD OF THIS TROUGH WILL BE OVER MINNESOTA ALONG WITH THE COLD FRONT TRACKING ACROSS THE NORTHERN PLAINS. CONDITIONS WILL STILL BE RELATIVELY DRY OVERNIGHT. THIS WILL KEEP CLOUD COVER OVER THE FORECAST AREA TONIGHT...HOWEVER...EXPECT TO SEE AN INCREASE IN CLOUD COVER. THE BLANKET OF CLOUDS WILL KEEP THE TEMPERATURES GENERALLY IN THE 50S. THE MID LEVEL RIDGE WILL SHIFT INTO THE LOWER GREAT LAKES ON MONDAY...AS THE HIGH PLAINS TROUGH RACES ACROSS THE DAKOTAS. THE SHORTWAVE ENERGY AND THE COLD FRONT WILL MOVE INTO CENTRAL U.P. ON MONDAY. ISENTROPIC LIFT AHEAD OF THE FRONT WILL TRIGGER RAIN SHOWERS. ANOTHER MORE INTENSE UPPER MID LEVEL TROUGH WILL MOVE INTO NORTHWEST MINNESOTA. GFS IS MOVING THE COLD FRONT ABOUT 2 TO 3 HOURS SLOWER THAN ETA. THE GLOBAL AGREES WITH THE ETA. Q-VECTOR CONVERGENCE WITH THE SHORTWAVE ENERGY AND THE MOISTURE ACCOMPANYING THE COLD FRONT WILL COMBINE TO PRODUCE SCATTERED SHOWERS OVER THE FORECAST AREA ON MONDAY AND MONDAY NIGHT. WARM ADVECTION AHEAD OF THE COLD FRONT WILL PUSH THE TEMPERATURES INTO THE UPPER 60S AND LOW 70S F ACROSS THE AREA ON MONDAY. CLOUD COVER WILL LIMIT RADIATION COOLING AND KEEP MONDAY NIGHT LOW TEMPERATURES AROUND 40F. THE SHORTWAVE OVER THE FORECAST AREA WILL MOVE INTO EASTERN ONTARIO ON TUESDAY. THE SURFACE RIDGE WILL MOVE INTO MID MISSOURI VALLEY AND PUSH THE COLD FRONT INTO THE LOWER GREAT LAKES. DRIER AIR WILL SPREAD ACROSS THE FORECAST AREA EARLY TUESDAY AND END THE RAIN SHOWERS. DRIER AIR AND CALM WINDS WILL WITH SETTLE OVER THE UPPER GREAT LAKES ON TUESDAY NIGHT AS THE SURFACE HIGH MOVE INTO THE REGION. COLD AIR ADVECTION AND RADIATIONAL COOLING WILL CAUSE THE TEMPERATURES TO FALL INTO THE MID AND UPPER 30S OVERNIGHT. MID RANGE MODELS IN VERY CLOSE AGREEMENT ON POSITION AND STRENGTHS OF SYSTEM MOVING THROUGH FORECAST AREA ON WEDNESDAY. A LONGWAVE TROUGH WILL BE OVER HUDSON BAY. A BROAD RIDGE REMAINS OVER BRITISH COLOMBIA. SHORTWAVE ENERGY WILL GLIDE DOWN THE LEE OF THE RIDGE REACHING THE FORECAST AREA WEDNESDAY NIGHT. SURFACE RIDGE WILL REMAIN ANCHORED OVER THE FORECAST AREA. CONDITIONS STILL LOOK DRY AND STABLE ENOUGH AT THE LOW LEVELS TO KEEP ANY PRECIPITATION FROM OCCURRING. THE GFS AND ECMWF DIG A TROUGH OVER THE FORECAST AREA ON THURSDAY...WHILE GEM IS A LITTLE SLOWER AND KEEPING IT OVER WISCONSIN. THE SOLUTIONS REMAIN VERY SIMILAR WITH ONLY MINOR TIMING DIFFERENCES. THE SURFACE RIDGE WILL RELOCATE OVER LAKE HURON. A LITTLE HIGHER LAYER RELATIVE HUMIDITY WILL PUSH INTO THE FORECAST AREA. WHEN COMBINED IT APPEARS THAT THERE IS A CHANCE OF SHOWERS OVER THE FORECAST ON THURSDAY. GEM AND GFS MERGE AGAIN ON SATURDAY BY DIGGING A MID LEVEL LOW OVER LOWER MICHIGAN...WHILE ECMWF PROGRESS A LITTLE FASTER EAST. A SURFACE RIDGE AND DRY AIR WILL AGAIN SPREAD ACROSS THE FORECAST AREA ON FRIDAY...KEEPING OUT ANY PRECIPITATION. THE MID LEVEL LOW WILL DIG INTO THE EASTERN OHIO VALLEY ON SATURDAY. THE MID LEVEL AND SURFACE RIDGES WILL BE OVER THE FORECAST AREA ON SATURDAY KEEPING THE AIR MASS RELATIVELY STABLE. ON SUNDAY...THE OHIO VALLEY LOW WILL PUSH INTO THE MID ATLANTIC STATES. A WEAK SURFACE RIDGE WILL REMAIN OVER THE FORECAST AREA...AND A WEAK SHORTWAVE WILL SLIDE INTO WESTERN U.P. THUS CHANCES ARE THAT THE WEST END OF FORECAST AREA WILL HAVE SOME RAIN SHOWERS. .MQT...FLOOD WARNING MIZ005 ALONG DEAD RIVER FROM SILVER LAKE TO THE CITY OF MARQUETTE UNTIL WATER RECEDES. DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 1030 AM EDT SUN MAY 18 2003 TRANQUIL WEATHER ACROSS THE AREA THROUGH THE NEXT 48 HOURS. MESO ETA GUIDANCE AND BUFKIT INDICATED SOME MOISTURE WITH BUILDUP TO 7 THOUSAND FEET AND A READ OUT OF SOME SHOWERS LATER THIS AFTERNOON. THIS IS ALONG WITH A STRONG VORTICITY MAX AND 700 MB LOW OVER EXTREME WESTERN COUNTIES. BUT INDICATIONS ON THE RUC ARE THAT THE VORT MAX WILL ALREADY BE ON THE PENNSYLVANIA LINE BY 18Z AND SATELLITE ONLY SHOWS A FEW CLOUDS ASIDE FROM THOSE PERSISTING OVER THE SOUTHERN TIER. THE ONES OVER THE SOUTHERN TIER ARE TRYING TO BREAK UP. WILL GO WITH SUN AND A FEW CLOUDS WITH MOSTLY SUNNY SKIES THIS AFTERNOON NORTH COUNTRY AND LEAVE OUT A SPRINKLE EXCEPT CATTARAUGUS AND ALLEGANY COUNTY NEAR THE STATE LINE. ALSO ADJUSTED TEMPERATURES UP A NOTCH TO INDICATE NEAR 70 MOST AREAS. REST OF DISCUSSION THE SAME. HIGH PRESSURE AND ASSOCIATED DRY AIR SETTLING OVER THE AREA TONIGHT AND MONDAY. MAINLY CLEAR/MOSTLY SUNNY FORECAST LOOKS REASONABLE. INCREASING HEIGHTS AND WARMER 850 MB TEMPERATURES SHOULD GET TEMPERATURES WELL INTO THE 70S MONDAY. ETA/GFS IN SIMILAR AGREEMENT BRINGING COLD FRONT INTO THE AREA LATE IN THE DAY TUESDAY. BOTH MODELS SUGGESTING PRECIPITATION WILL HOLD OFF UNTIL LATE AFTERNOON FOR AREAS WEST OF ROCHESTER. FRONT AND ASSOCIATED PRECIPITATION WILL CROSS THE AREA TUESDAY NIGHT. HIGH PRESSURE AND DRYING TO FOLLOW ON WEDNESDAY. .BUF...NONE. $$ TMA ny AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 810 PM MDT SUN MAY 18 2003 SEVERE THUNDERSTORM WATCH HAS BEEN DROPPED FOR REST OF SOUTH DAKOTA COUNTIES. CURRENT SURFACE MAP SHOWS COLD FRONT THROUGH ALL OF THE CWA. WINDS STARTING TO PICK UP FROM BUFFALO TO RAPID CITY...WITH GUSTS OVER 30 KNOTS. TIGHT PRESSURE GRADIENT ACROSS THE AREA WITH STRONG LOW LEVEL COLD ADVECTION. WIND ADVISORY LOOKS GOOD. KUDX 88D SHOWS AN INCREASE IN SHOWER ACTIVITY ACROSS THE NORTHWEST DURING THE LAST HOUR. THIS IS IN LINE WITH 00Z RUC/ETA. WILL CONTINUE WITH SCATTERED SHOWERS IN THE FORECAST. 00Z RUC/ETA KEEPS COLDEST AIR NORTHWEST OF THE PRECIPITATION...BUT WILL TURN COLD ENOUGH FOR RAIN/SNOW OVER NORTHEAST WYOMING AND THE BLACK HILLS TOWARDS MORNING. .UNR...WIND ADVISORY TONIGHT FOR MUCH OF WRN SD. $$ sd COASTAL BEND FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 930 AM CDT SUN MAY 18 2003 WEAK EASTERLY FLOW IS EVIDENT ACROSS MOST OF AREA THIS MORNING AS EARLIER BOUNDARY IS BECOMING HARDER TO DETECT. DEWPOINTS ARE STILL IN THE 60S THIS MORNING NEAR VCT BUT RUC40/06 UTC GFS SHOWS EVOLUTION OF SSE FLOW LATER TODAY AS SURFACE TROUGH DEVELOPS OVER FAR WEST TEXAS. NO SIGNIFICANT UPDATES TO GRIDS. A NEW ZFP WILL BE ISSUED TO REMOVE EARLIER DENSE FOG ADVISORY. .CRP...NONE. AP...72 (SHORT TERM) tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 352 AM EDT MON MAY 19 2003 BIGGEST FORECAST CONCERN IS COLD FRONT WHICH WILL SWEEP THROUGH THE REGION TONIGHT...AND PCPN/WINDS ASSOCIATED WITH IT. SFC COLD FRONT CURRENTLY STRETCHING FROM NRN MN TO CENTRAL NE MOVING SLOWLY EWD...AS UPR SW FLOW IS NEARLY PARALLEL TO IT. CONVECTION IS MAINLY ALONG AND JUST BEHIND THE FRONT...AS AMS W/IN WARM SECTOR IS CAPPED (H7 TEMPS TO 6C OVER THE U P). WV IMAGERY SHOWS DRIVING UPR TROF NOW PUSHING OUT OF THE NRN ROCKIES...WITH BLOCK HOLDING OVER THE ERN STATES. THERE IS SOME SERIOUSLY COLD AIR BEHIND THE FRONT... AS DEPICTED BY SWATH OF NEGATIVE H8 TEMPS FROM CYQD TO KTFX AT 00Z. MESOETA AND RUC SHOW CONVECTIVE PCPN DEVELOPING BY AROUND 15Z INTO WEST AND CENTRAL PARTS OF THE CWA...BUT BELIEVE THIS TO BE OVERDONE. GOOD THETA-E ADVECTION AND ASSOCIATED MOISTURE CONVERGENCE PRODUCING AREA OF STRATOCU IN WI...STRETCHING AS FAR NORTH AS IMT AT 07Z. AM EXPECTING THIS SC TO OVERSPREAD MUCH OF THE WRN 2/3 OF THE CWA EARLY THIS MORNING...AND THIS WILL GREATLY REDUCE ANY POSSIBILITY OF SFC BASED PCPN FOR MUCH OF TODAY (IN ADDITION TO MID LEVEL CAP). LLJ FORCING ACTUALLY DIMINISHES THROUGH THE MORNING AS WELL...SO DO NOT ANTICIPATE ANYTHING MORE THAN 3-5KFT CLD DECK TODAY...EXTENDING VERTICALLY TO NO HIGHER THAN 750-800MB WHERE BASE OF INVERSION AND DRY MID LEVEL AIR IS. THIS WON'T GENERATE PCPN. TEMPS ARE A BIT TRICKY TODAY CONSIDERING EXPECTED ONSET OF LOWER CIGS. THIS WILL HOLD TEMPS DOWN SIGNIFICANTLY...AS GUIDANCE IS SHOWING...DESPITE H9 TEMPS WHICH WARM TO 18C IN WEST THIS AFTN IN THERMAL RIDGE AXIS. GUIDANCE MAY BE A LITTLE COOL (IWD IS 63F AT 07Z)...BUT WILL GO NO HIGHER THAN MID 60S TO AROUND 70F. EAST SHOULD BE WARMEST THANKS TO THINNEST CLOUD COVER. MAY SEE SHRA/TS BEGIN TO DEVELOP OUT WEST LATER THIS AFTN...WHERE MESOETA HINTS AT FORMATION OF PREFRONTAL SFC TROF AND REGION BECOMES UNDER DIVERGENCE ALF IN RRQ OF JET. BY THIS TIME...H7 TEMPS BEGIN TO COOL AS WELL. SO...HAVE INTRODUCED SCT TSRA IN GRIDS BEGINNING AT 19Z IN GOGEBIC COUNTY. STRONG FRONTAL LIFT WILL BE FOCUS OF PCPN THIS EVENING AND OVERNIGHT. ONLY QUESTION WILL BE TIMING OF FRONT...BUT MODELS ALL GENERALLY AGREE IN TRACKING IT FROM NEAR IWD AT 22Z THROUGH THE ENTIRE CWA BY AROUND 09Z. THERMAL GRADIENT IS IMPRESSIVE...WITH H8 TEMPS RANGING FROM 13C OVER THE U P...TO -5C IN NORTHWEST MN. HEAVIEST PCPN WILL BE SHORT-LIVED...BUT QPF OF HALF INCH SHOULD BE REASONABLE GIVEN PWATS IN EXCESS OF AN INCH. PCPN SHOULD EXIT THE EAST BY MORNING AS VERY DRY AIR ADVECTS INTO THE AREA FROM THE NW. WINDS WILL ALSO BECOME A CONCERN TONIGHT DUE TO STRONG CAA/ SUBSIDENCE/PRES RISES BEHIND FRONT. ETA SHOWS 40-45KT AT 2KFT...AND THIS SHOULD BE LARGELY FELT AT SFC AS LOW LEVEL MIXING IMPROVES. WILL MENTION GALES ON LAKE...AND WIND ADVISORY WILL BE A POSSIBILITY ON KEWEENAW PENINSULA AND ERN LAKE SUPERIOR ZONES. GUSTY WINDS WILL CONTINUE THROUGH TUE AFTN AS BLYR WINDS STAY IN 20-30 KT RANGE. TEMPS TUE WILL BE DOWN CONSIDERABLY...OF COURSE. MIXING TO 850MB (WHERE TEMPS WILL BE BELOW ZERO) WOULD YIELD HIGHS IN UPPER 40S AND 50S...WARMEST NEAR LAKE MICHIGAN WHERE NW WINDS WILL DOWNSLOPE. HIGH PRESSURE WILL DOMINATE WX THROUGH WED...THOUGH COLD POOL ALF (-27C AT 500MB) COMBINED WITH SFC HEATING MAY PRODUCE DIURNAL CU INLAND. NO CHANGES TO EXTENDED. .MQT...FLOOD WARNING MIZ005 ALONG DEAD RIVER FROM SILVER LAKE TO THE CITY OF MARQUETTE AND LAKE SUPERIOR CONTINUES UNTIL WATER RECEDES. GALE WARNING E HALF LAKE SUPERIOR. JKL mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1100 AM EDT MON MAY 19 2003 FOG BURNING OFF NICELY EAST OF THE MOUNTAINS...WITH SOME WAY TO GO IN THE SHENANDOAH VALLEY AND NEAR THE MOUNTAINS. HAVE UPDATED THE ZONES TO WORD SKY CONDITION MOSTLY SUNNY FOR MOST AREAS. WILL SEE SOME SCT LOW CLOUDS AS FOG BURNS OFF WITH MIXING EARLY THIS AFTERNOON. RIGHT REAR QUAD OF 250 MB JET OVER MID ATLANTIC WILL ALSO PRODUCE SCATTERED CIRRUS...WITH SOME MID LEVEL CLOUDS ACROSS SOUTHWEST PORTION OF CWA WITH MOISTURE FROM MIDWEST SYSTEM RIDING AROUND MIDLEVEL RIDGE. HAVE ALSO BUMPED UP TEMPERATURES ACROSS MOST OF THE AREA BASED ON RUC CROSS SECTIONS GENERALLY SHOWING MIXING UP TO 850MB WITH TEMPERATURES WARMING TO 8-9C BY MID AFTERNOON. ROGOWSKI .LWX... DC...NONE. MD...NONE. VA...NONE WV...NONE. MARINE...NONE. md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1140 AM EDT MON MAY 19 2003 ...UPDATED FORECAST TO ADD SCATTERED SHOWERS FOR THIS AFTERNOON... WHILE THERE CURRENTLY IS NOT MUCH IN THE WAY OF SHOWERS AROUND...EXCEPT FOR THE CONVECTION ON THE COLD FRONT THERE IS A SHORTWAVE THE DOES SHOW UP ON THE WATER VAPOR IMAGES OVER CNTRL IOWA. THAT SHORTWAVE WILL MOVE EAST AND CROSS THE WARM FRONT (BASED ON DEW POINT DISCONTINUITY AND SURFACE PRESSURE PATTERN) WHICH AT 15Z WAS NEAR CHI TO SBN. BOTH THE ETA AND RUC SHOW A CONSIDERABLE INCREASE IN THE MEAN 850 TO 700 RH AS THAT SHORTWAVE MOVES INTO WRN LOWER MICHIGAN LATE THIS AFTERNOON. THERE IS SIGNIFICANT 700 TO 300 MB DPVA AND DECENT SFC TO 850 THTE ADVECTION AT THE SAME TIME. PWT VALUES INCREASE FROM AROUND 1" TO NEAR 1 1/2" OVER THE SW CORNER OF THE CWA BY 00Z. I HAVE TO ADMIT THE WARM ADVECTION/ISENTROPIC LIFT IS FEEBLE THOUGH. ALSO THERE IS A CONSIDERABLE AMOUNT OF UPSTREAM LOW LEVEL CLOUDS... SO SURFACE HEATING IS NOT MUCH OF A FACTOR EITHER. PUTTING ALL OF THIS TOGETHER... I ADDED SCATTERED SHOWERS TO THE AFTERNOON FORECAST OVER THE WESTERN CWA (WHERE THE BEST MOISTURE INCREASE IS). THERE DOES NOT SEEM TO BE ENOUGH INSTABILITY FOR THUNDERSTORMS THIS AFTERNOON OVER SOUTHWEST MICHIGAN. THE UPDATE HAS ALREADY BEEN ISSUED. .GRR...NONE. WDM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1113 AM EDT MON MAY 19 2003 BIGGEST FORECAST CONCERN WITH THIS FORECAST UPDATE IS THE COLD FRONT WHICH WILL APPROACH THE REGION THIS AFTERNOON. WATER VAPOR IMAGERY AND RUC/ETA SHOWING A RIDGE OVER THE LOWER GREAT LAKES AND A TROUGH OVER SOUTH CENTRAL CANADA. SHORTWAVE ENERGY BEING EJECTED OUT OF THE BASE OF THE TROUGH IS MOVING THROUGH MINNESOTA AND NORTHERN WISCONSIN. SURFACE ANALYSIS DEPICTS A COLD FRONT STRETCHING FROM A LOW OVER HUDSON BAY THROUGH KDLH AND KOMA TO A LOW OVER CENTRAL KANSAS. A 328K THETA-E RIDGE STRETCHES THROUGH ILLINOIS AND ANOTHER IS OVER COLD FRONT INTO WESTERN IOWA AND SOUTHERN MINNESOTA. THUNDERSTORMS ARE FIRING AHEAD OF THE COLD FRONT IN VICINITY OF THE SHORTWAVE AND THETA-E RIDGE MOVING THROUGH WESTERN IOWA. LAMP GUIDANCE TEMPERATURES ARE VERIFYING FAIRLY WELL THIS MORNING. THE SHORTWAVE WILL REACH INTO NORTHERN WISCONSIN THIS AFTERNOON. THE COLD FRONT WILL PUSH INTO NORTHERN WISCONSIN. THE THETA-E RIDGE WILL REACH WESTERN U.P. BY 21Z THIS AFTERNOON. A 30 KNOT LOW LEVEL JET WILL SHIFT OVER THE FORECAST AREA THIS AFTERNOON. HOWEVER...A SURFACE BASE INVERSION WILL LIMIT THESE WINDS FROM MIXING TO THE SURFACE. EXPECT ENOUGH MOISTURE AND INSTABILITY TO KEEP CLOUDY CONDITIONS THROUGH THE AFTERNOON. K-INDEX WILL REACH 34 OVER WESTERN U.P. SBCAPE WILL REACH ONLY ABOUT 500J/KG OVER THE WEST. LIFTED INDEX WILL DECREASE TO -2 OVER THE WEST. ISENTROPIC ANALYSIS SHOWING A FAIR AMOUNT OF ASCENT AHEAD OF THE FRONT. CONDITION LOOK FAVORABLE FOR THE CONTINUED DEVELOPMENT OF THUNDERSTORMS. HOWEVER...WITH MARGINAL LI'S AND CAPE...DO NOT EXPECT TO SEE ANY SEVERE. PLAN TO GO WITH CURRENT FORECAST...ONLY TO TWEAK THE WORDING. AS MORE PRECIPITABLE WATER INCREASES TO GREATER THAN 1.5 INCH OVER THE U.P. THIS EVENING...THUNDERSTORMS SHOULD BECOME MORE NUMEROUS. .MQT...FLOOD WARNING MIZ005 ALONG DEAD RIVER FROM SILVER LAKE TO THE CITY OF MARQUETTE AND LAKE SUPERIOR CONTINUES UNTIL WATER RECEDES. GALE WARNING E HALF LAKE SUPERIOR. DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 1115 AM CDT MON MAY 19 2003 MAIN FOCUS FOR THE AFTERNOON IS POTENTIAL FLOODING IN NW WI. THE PREFRONTAL BAND OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUED TO MOVE SLOWLY EAST THIS LATE MORNING. THE MAIN PROBLEM FOR THE AFTERNOON HINGES ON THE FLOOD WATCH CURRENTLY IN PLACE ACROSS NW WI. COOPERATIVE OBSERVERS THIS MORNING REPORTED SEVERAL AMOUNTS AROUND 1.25 INCHES...FROM BOVEY TO EMILY TO BRAINERD. THE LATEST RUC GUIDANCE INDICATES THAT THE LI VALUES WILL DROP TO ABOUT -3C ACROSS NW WI...WITH PRECIPITABLE WATER OF 1.6 INCHES. WITH SUCH A SLOW MOVING BAND OF PRECIPITATION AND THE POTENTIAL FOR SOME SLOW MOVING EMBEDDED THUNDERSTORMS THIS AFTERNOON...WILL HANG ON TO THE FLOOD WATCH. COULD BE SOME TRAINING OF STORMS ALONG AND AHEAD OF THE FRONT AS WELL. SINCE THE GROUND HAS NOT HAD A LOT OF TIME TO DRY OUT FROM THE LAST DELUGE...RIVERS AND STREAMS MAY RESPOND RATHER QUICKLY. TEMPS WILL BE QUITE VARIED TODAY...WITH TEMPERATURES POSSIBLY DROPPING HOLDING IN THE 50S IN THE WESTERN CWA...AND REACHING THE LOWER TO MIDDLE 70S IN NW WI. GUSTY NORTHWEST WINDS STILL ANTICIPATED FOR THE AFTERNOON...WITH SOME GUSTS ALREADY SHOWING UP AT INL AT 16Z. .DLH...FLOOD WATCH WIZ001>004-006>009. $$ DAP mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 909 AM EDT MON MAY 19 2003 CURRENT OBS SHOW PERSISTENT COOL MOIST NORTHEAST FLOW IN THE LOWER LAYERS WITH TEMPERATURES MUCH BELOW NORMAL EXPECTED TODAY. CROSS SECTIONAL ANALYSIS OF OBSERVED DATA AND SHORT RANGE MODEL PROJECTIONS FROM THE RUC SHOW SUBSIDENCE BEGINNING IN THE NORTHEAST AROUND WAL THIS MORNING AND WORKING SOUTHWEST INTO THE RAH CWA THIS AFTERNOON. THIS TURNS CURRENT CONFLUENT UPGLIDE FLOW ON THE 300-310K THETA SURFACES TO SINKING MOTION. LINGERING RAIN SHOULD DIMINISH THE NEXT COUPLE OF HOURS. OVERCAST WILL CONTINUE SOUTH AND WEST...BUT A FEW BREAKS TO PARTLY SUNNY SKIES ARE EXPECTED NORTHEAST OF ROXBORO TO RDU TO WILSON THIS AFTERNOON. UPDATED FORECASTS WILL REFLECT THESE TRENDS. .RAH...NONE. RFG nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 1016 AM EDT MON MAY 19 2003 SATELLITE IMAGERY THIS MORNING REVEALS ALMOST COMPLETELY OVERCAST SKIES OVER THE CWFA...EXCEPT FOR SOME BREAKS ALONG THE FRENCH BROAD VALLEY TOWARD THE TENNESSEE BORDER. AREA SOUNDINGS REVEAL ABUNDANT LOW LEVEL MOISTURE...WHICH WILL BE HARD TO SCOUR TODAY DESPITE THE PRESENCE OF DRY AIR ALOFT. WATER VAPOR IMAGERY SHOWS ADDITIONAL DRY AIR PUMPING INTO THE REGION FROM THE NORTH. TO THE SOUTHWEST...THE UPPER LOW CONTINUES TO SPIN CLOSE TO THE GULF COAST AND SLIPS SLOWLY SOUTHWARD. AT THE SURFACE...COOL HIGH PRESSURE CONTINUES TO BUILD INTO THE SOUTHEAST STATES FROM THE NORTHEAST. WEDGE FRONT...OR BOUNDARY BETWEEN REALLY JUICY AIR TO OUR SOUTHWEST...CONTINUES A SLOW DRIFT SOUTHWARD. WITHIN THE DAMMING REGION...THERE RESIDE A FEW SURFACE TROFS...OR WIND SHIFT AXES...WHICH OCCASIONALLY MAKE THEMSELVES KNOWN ON THE RADAR IMAGERY IN THE WAY OF BOUNDARIES AND/OR ATTEMPTED ORGANIZED LINES OF LIGHT RAIN. PRECIPITATBLE WATER ON THE FFC SOUNDING THIS MORNING VERY HIGH. LATEST RUC AND 06Z ETA BOTH PROG A FLATTENING UPPER VORT TO ROTATE AROUND THIS LOW...WITH BOTH MODELS PRODUCING A LINE OF AFTERNOON CONVECTION FROM NORTH GEORGIA SOUTH ALONG THE WEAK WEDGE FRONT INTO SOUTH CAROLINA. HOWEVER...SUBSIDENCE WILL BE INCREASING FROM THE NORTH TODAY...AND MAY GET AN ENHANCEMENT FROM THE BACK SIDE OF ANOTHER UPPER LOW SPINNING OFF THE MID ATLANTIC. FOR THE UPDATE...DECIDED TO KEEP 50 POPS IN TH3 SOUTHWEST CWFA...AND TAPER OFF TO 30S EASTWARD TO THE NORTHWEST PIEDMONT AND THE CHARLOTTE AREA FOR THE AFTERNOON. WILL CONTINUE CHANCE OF RAIN/DRIZZLE WORDING...ALTHOUGH COULD NOT RULE OUT A CONVECTIVE ELEMENT OR TWO THIS AFTERNOON WITH ANY HEATING...ALTHOUGH IT WILL BE MINIMAL. INCREASED WIND SPEEDS TO BETWEEN 10 AND 15 EVERYWHERE TODAY...EXCEPT 15 TO 20 FROM THE NORTHEAST IN THE SOUTH CAROLINA AND GEORGIA MOUNTAINS. WITH FEW...IF ANY...BREAKS IN THE OVERCAST EXPECTED THIS AFTERNOON...TRENDED LOWER ON MAX TEMPS...OPENING UP A RANGE OF 60 TO 65 MOST AREAS...WITH 61 TO 66 FOR NORTHEAST GEORGIA AND THE MAJORITY OF UPSTATE SOUTH CAROLINA. FCSTID = 44 GSP 63 56 73 61 / 40 30 40 60 AND 64 57 74 62 / 50 30 50 60 CLT 63 56 72 61 / 30 20 20 50 HKY 62 54 72 60 / 30 20 30 60 AVL 63 54 71 57 / 40 30 60 80 .GSP... GA...NONE. NC...NONE. SC...NONE. $$ BURRUS sc EAST CENTRAL FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 328 PM EDT MON MAY 19 2003 CURRENTLY... EAST COAST SEA BREEZE HELPING TO PRODUCE SCATTERED THUNDERSTORMS OVER THE INTERIOR MAINLY WEST OF INTERSTATE 95. AN OUTFLOW BOUNDARY MOMENTARILY INCREASED BUOY 009/S WINDS TO 15 TO 20 KNOTS BUT...THE WINDS SHOULD SETTLE BACK TO 10 TO 15 KNOTS ONCE THE EFFECT OF THE BOUNDARY PUSHING THROUGH WEARS OFF. CUTOFF LOW OVER LA/MS SLOWLY MOVING SOUTH ACROSS THE MS DELTA AND INTO THE NORTH GULF OF MEXICO WHILE HIGH PRESSURE OVER NEW ENGLAND/MID ATLANTIC STATES CONTINUES TO RIDGE SOUTHWEST ALONG THE EASTERN SEABOARD...NORTH FLORIDA AND INTO THE NORTHEAST GULF OF MEXICO. TONIGHT...WATER VAPOR LOOP SHOWS DRIER AIR WRAPPING AROUND THE SOUTHEAST QUADRANT OF THE CUTOFF LOW OVER LA/MS AND MOVING TOWARD THE CENTRAL FLORIDA PENINSULA. THE COMBINATION OF MID LEVEL DRIER AIR AND 500MB RIDGING OVER THE AREA APPEARS TO BE INHIBITING CONVECTION TO A DEGREE AND THE RUC FORECAST AT 20/03Z STILL HAS 500MB RIDGING OVER THE PENINSULA. CURRENT 20/30 COASTAL/INTERIOR SPLIT OF STORMS LOOKS GOOD BUT WILL CONTINUE THEM LONGER INTO THE NIGHT AS THE RIDGING OVER THE PENINSULA WEAKENS. TUESDAY AND WEDNESDAY...CUTOFF OVER THE NORTH GULF OF MEXICO CONTINUES TO FILL AS IT SLOWLY MOVES SOUTH WILL THE RIDGE AXIS REMAIN TO OUR NORTH. EXPECT EASTERLY WINDS TO PERSIST AND INCREASE TO 10 TO 15 MPH ALONG THE COAST AS THE SEA BREEZE ESTABLISHES ITSELF IN THE AFTERNOON. SCATTERED THUNDERSTORMS/SHOWERS WILL BE THE RULE AGAIN AS THE SEA BREEZE PUSHES INLAND. THURSDAY THROUGH SATURDAY...THE GFS AND OTHER LONGER TERM MODELS STILL WANT TO DEVELOP A LOW OVER THE SOUTHEAST STATES AND MOVE ACROSS NORTH FLORIDA THEN ALONG THE EAST COAST OVER THE WEEKEND. IF THIS VERIFIES EXPECT A PERIOD OF SOUTHWEST TO WEST WINDS AND TEMPERATURES A COUPLE OF DEGREES ABOVE GUIDANCE/CLIMO DUE TO THE SOUTHWEST TO WEST FLOW ACROSS THE LAND MASS. SUNDAY AND MEMORIAL DAY/MONDAY...AS THE LOW PRESSURE WORKS IT WAY ALONG THE EAST COAST HIGH PRESSURE BUILDS ACROSS THE SOUTHEAST AND GULF OF MEXICO AND EVENTUALLY MERGING WITH HIGH PRESSURE OVER THE BAHAMAS. WITH THE RIDGE AXIS AND CENTER OF HIGH PRESSURE TO OUR NORTH WE SHOULD BE IN A NORTH TO NORTHEAST FLOW BY MONDAY. MARINE...AGAIN WITH HIGH PRESSURE TO THE NORTH...EASTERLY WINDS WILL PERSIST THROUGH WEDNESDAY. THE EASTERLY WINDS WILL ALSO MAINTAIN THE CURRENT 4 TO 5 FOOT LONG PERIOD SWELL MOVING ACROSS THE COASTAL WATERS. ON THURSDAY THE WINDS VEER TO THE SOUTH AS LOW PRESSURE DEVELOPS OVER THE SOUTHEAST STATES AND MOVES EAST NORTHEAST. FRIDAY THE WINDS SHIFT TO THE SOUTHWEST AND WEST AS A WEAK COLD FRONT IS FORECAST TO MOVE OVER FLORIDA. PRELIMINARY CCF... DAB BB 072/084 069/084 071 2313 MCO BB 072/088 069/088 072 3442 MLB BB 073/086 071/086 073 2313 .MLB...NONE. PUBLIC/MARINE...WIMMER AVIATION/FIRE...SHARP $$ fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 155 PM EDT MON MAY 19 2003 CURRENTLY: LATEST WATER VAPOR IMAGERY/RUC H5 COMPOSITE SHOWS CLOSED UPPER LOW ALONG THE MS GULF COAST CONTINUING ITS SLOW SWD DRIFT. SEVERAL VORT MAXIMA ROTATING AROUND LOW...W/ ONE OFF THE PANHANDLE COAST RESPONSIBLE FOR SCATTERED CONVECTION. OUTFLOW BOUNDARY FROM THIS CONVECTION MOVED INTO THE FL BIG BEND/FAR SW GA. INTERACTION W/ THIS BOUNDARY & THE GULF SEA BREEZE CONTINUES TO SPARK ADDITIONAL SHWRS/TSTMS. IT APPEARS BEST THREAT FOR ANY STRONG TSTMS THIS AFTN WILL BE OVER S/CNTRL GA & ERN BIG BEND WHICH HAVE SEEN MORE INSOLATION...W/ CAPES OF 2000+ J/KG & LI'S FROM -4 TO -6. MODELS/FORECAST: 12Z MODELS IN GOOD AGREEMENT W/ CONTINUED SWD PROGRESSION & WEAKENING OF UPPER LOW INTO THE CENTRAL GULF OF MEXICO DURING THE NEXT 12 TO 36 HRS. MEANWHILE...UPPER RIDGE OVER THE ERN CONUS GETS SUPPRESSED AS S/WAVE TROUGH SKIRTS ACROSS THE NRN TIER U.S. SURFACE HIGH WEDGES SWD ALONG THE ATLANTIC COAST WHICH WILL INCREASE THE LOW-LEVEL E-SELY FLOW THRU WED. PWAT VALUES CONTINUE TO EDGE UPWARD TO NEAR 2" ON WED. COLD FRONT APPROACHING THE MS VALLEY TONIGHT WILL MOVE THRU THE OH/TN VALLEYS EARLY WED....AND INTO NRN GA/AL WED AFTN. SURFACE WAVE FORMS ALONG BOUNDARY OVER AL...WHICH WILL SLOW ITS SEWD PROGRESS. GFS IS TRENDING A BIT FASTER W/ FRONTAL MOTION THAN ETA/NGM. PERIOD OF MAX LIFT/DYNAMICS LOOKS LIKE IT WILL OCCUR BETWEEN 18Z WED & 06Z THU. DECENT INSTABILITY...AMPLE GULF/ATLANTIC MOISTURE & SEA BREEZES WILL KEEP SCATTERED MAINLY AFTERNOON/EVENING SHWRS/TSTMS THRU TUE NIGHT. HAVE INCREASED POPS TO LIKELY ALL BUT SE BIG BEND FOR WED. PCPN ENDS W/ FROPA FROM NW TO SE ON THU. PORTIONS OF ERN PANHANDLE RECEIVED 3-5" OF RAIN EARLIER TODAY. ATTM...DURATION/AREAL COVERAGE OF HEAVY RAINFALL SHOULD BE LIMITED TO PRECLUDE A FLOOD WATCH. MODEL BASIN-AVERAGED QPF VALUES DURING THE NEXT 48 HRS SHOULD RANGE FROM 0.5 TO 1" W/ ISOLATED 1-2" AMOUNTS POSSIBLE. MARINE: NO HIGHLIGHTS OR CHANGES TO SHORT TERM. SELY WINDS BELOW 15 KTS & SEAS 4 FT OR LESS THRU 48 HRS. WINDS VEER TO SW-W ON WED AHEAD OF COLD FRONT...THEN BECOME NW-N ON THU AFTER FROPA. FIRE WEATHER: NO REQUIREMENTS. EXTENDED (FRI-MON): UPCOMING MEMORIAL DAY WEEKEND STILL LOOKING SEASONABLY WARM & DRY AS SURFACE HIGH PRESSURE BUILDS INTO THE AREA FROM THE NW PER GFS. .PRELIMINARY POINT TEMPS/POPS... TLH 69 86 69 85 / 40 50 40 60 PFN 72 84 72 83 / 40 50 40 60 DHN 69 83 69 82 / 40 50 50 60 ABY 68 84 67 83 / 40 50 40 60 VLD 68 86 67 85 / 40 50 40 60 CTY 69 87 68 86 / 30 50 30 50 .TLH WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...NONE. $$ MAJ fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 210 PM CDT MON MAY 19 2003 PUBLIC FORECAST DISCUSSION FOR PM ZONES/GRIDS... SHOWERS POPPING UP ALL ACROSS CWA THIS AFTN WHILE MAIN ONSLAUGHT OF TSTMS STILL IN IA AND MO. TSTMS CROSSING MS RVR NEAR 7PM ALONG WITH COLD FRONT AND REACHING RFD ABT 9PM AND PAST CHI BY MDNGT. SHUD BE SOME RESIDUAL SHOWERS/OVC SKIES INTO MRNG HOURS TUESDAY...THEN CLRG IN AFTN AND ERY EVE. SHUD BE A CATEGORICAL EVENT WITH POPS NR 100%... DIMINISHING TO 60% IN MRNG. ETA STILL KEEPING HIGHS IN MID 50S TMRW WHILE AVN/NGM RECOVERING TMPS TO AROUND 60. WILL GO WITH THE LATTER CONSIDERING TIME OF YEAR AND ASSUMING SOME SUNSHINE BREAKS OUT IN AFTN. MAXES MAY BE LATE IN THE DAY. THIS OF COURSE APPLIES TO INLAND LOCATIONS AWAY FROM LAKE WHICH WUD LIKELY HAVE HIGHS ONLY IN MID 50S AT BEST. CLR SKIES TUE NGT AND RATHER SUNNY FOR WED AS HIGH BUILDING DOWN LAKE MICHIGAN. WNDS STILL OFF THE LAKE WED THRU SATURDAY. THUS NO 70S UNTIL THEN...AND THEN ONLY SOUTH OF I-80. BROAD UPR RIDGE SLIPPING ACROSS MIDWEST FRIDAY WITH JET DIVING SOUTH FROM UPR TO MID MS VLY. SOME SHOWERS PSBL WEST OF CWA BUT KEEPING IT SOMEWHAT CLDY BUT DRY UNTIL SUN NGT. AT THAT TIME THAT SAME UPR TROF DEEPENS OVER OH VLY AND STARTS RETROGRADING BACK TO SRN MICHIGAN WITH FURTHER DEEPENING SUNDAY...THEN TO CHI ON TUESDAY. WILL BRING SHOWERS IN SUNDAY NIGHT AND CONTINUE INTO MONDAY FOR CHI AREA/NW INDIANA. .CHI...NONE RLB AVIATION DISCUSSION FOR 18Z TAFS RADAR SHOWS SHOWERS DEVELOPING RAPIDLY IN WESTERN AND NORTH CENTRAL ILLINOIS. THE SHOWERS ARE DEVELOPING IN A DEFORMATION AREA SEEN ON THE PROFILER DATA AT 700 MB. THERE IS DESTABILIZATION OCCURRING AS WELL. THE LOW CLOUDS EXTEND FAR WEST INTO WESTERN IOWA AND MINNESOTA. THE RUC40 MODEL SHOWS THE CAPE INCREASING 2100 UTC TO 0000 UTC THIS EVENING OVER NORTH ILLINOIS. WITH THE SHOWERS DEVELOPING QUICKLY WILL MENTION SHOWERS IN THE THE TAFS FOR THIS LATE AFTERNOON AND EVENING...AFTER 23 UTC. THIS IS FOR ORD...MDW...DPA AND GYY. THE SHOWERS ARE CLOSE TO RFD. WILL FORECAST THE SHOWERS AFTER 20 UTC. THERE IS NO LIGHTNING WITH THESE SHOWERS. LIFTED INDEX FORECASTS SHOW THE RAPID INCREASE IN INSTABILITY FROM 21 UTC TO 03 UTC. WILL FORECAST THUNDERSTORMS FOR RFD AFTER 02 UTC FOR ALL THE TAFS. THIS FRONT WILL BE NARROW WITH A RAPID WIND SHIFT. WILL FORECAST NORTHWEST WINDS AFTER 06 UTC. WHW il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 1241 PM CDT MON MAY 19 2003 AVIATION DISCUSSION FOR 18Z TAFS RADAR SHOWS SHOWERS DEVELOPING RAPIDLY IN WESTERN AND NORTH CENTRAL ILLINOIS. THE SHOWERS ARE DEVELOPING IN A DEFORMATION AREA SEEN ON THE PROFILER DATA AT 700 MB. THERE IS DESTABILIZATION OCCURRING AS WELL. THE LOW CLOUDS EXTEND FAR WEST INTO WESTERN IOWA AND MINNESOTA. THE RUC40 MODEL SHOWS THE CAPE INCREASING 2100 UTC TO 0000 UTC THIS EVENING OVER NORTH ILLINOIS. WITH THE SHOWERS DEVELOPING QUICKLY WILL MENTION SHOWERS IN THE THE TAFS FOR THIS LATE AFTERNOON AND EVENING...AFTER 23 UTC. THIS IS FOR ORD...MDW...DPA AND GYY. THE SHOWERS ARE CLOSE TO RFD. WILL FORECAST THE SHOWERS AFTER 20 UTC. THERE IS NO LIGHTNING WITH THESE SHOWERS. LIFTED INDEX FORECASTS SHOW THE RAPID INCREASE IN INSTABILITY FROM 21 UTC TO 03 UTC. WILL FORECAST THUNDERSTORMS FOR RFD AFTER 02 UTC FOR ALL THE TAFS. THIS FRONT WILL BE NARROW WITH A RAPID WIND SHIFT. WILL FORECAST NORTHWEST WINDS AFTER 06 UTC. WHW PUBLIC FORECAST DISCUSSION FOR AM ZONES/GRIDS... NEXT SYSTEM ON TRACK THIS AM AS H5 TROUGH MOVES EAST ALONG CANADIAN BORDER ON NORTHERN PLAINS. AT THE SURFACE COLD FRONT EXTENDS FROM NEAR INL SOUTHWEST TO GLD WITH RW/TRW AHEAD OF FRONT. MODLES STILL IN AGREEMENT IN KEEPING CLOUD COVER IN AREA THROUGH TODAY AND THEN BRINGING PCPN INTO WESTERN PORTIONS OF FORECAST AREA AROUND 00Z. FROPA EXPECTED AROUND 06Z IN NORTHEAST IL WITH MAX UVV. SHOWERS AND THUNDERSTORMS SHOULD BEGIN DURING THE EVENING HOURS AND CONTINUE AFTER FROPA. POST FRONTAL PRECIP LINGERS THROUGH MID MORNING TUESDAY IN EASTERN PORTIONS. POST FRONTAL WINDS SHIFT RAPIDLY TO NORTH WITH SPEEDS INCREASING TO 20 MPH THROUGH MOST OF TUESDAY. TEMPS WILL DROP NOTICEBALY FROM TODAYS AS MAXS ONLY AROUND 60. BROAD SURFACE HIGH SITS OVER CENTRAL US/UPPER LAKES AND EEPS WINDS FROM NORTHEAST FOR REMAINDER OF THE FORECAST CYCLE. THIS WILL GENERALLY HOLD CHI TEMPS BLO SLOWLY WARMING TEMPS OVER REMAINDER OF AREA. BROAD TROUG DEVELOPS ALOFT WITH AXIS THROUGH THE CWA BY FRIDAY. AVN INDICATES WAVES ROTATING THROUGH WESTERN PORTION OF TROUGH BY 12Z FRIDAY BUT MOISTURE APPEARS IN SHORT SUPPLY SO WORST APPEARS TO BE SOME INCREASE IN CLOUDINESS BUT NO PRECIP. AFTER TONIGHT/TUESDAY AM THEN FORECAST IS FOR DRY WX. .CHI...NONE il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 345 PM CDT MON MAY 19 2003 STRNG COLD FRNT 3/4 OF THE WAY THRU THE CWA AND IS THE MAIN CONCERN IN MY FCST PACKAGE. FRNT MAKING PROGRESS NOW AS LEAD H7 WAVE LIFTS OUT OF IA...AND MAIN H5 TROF MOVES INTO ERN DAKS. ENUFF INSTABILITY (SBLI TO -2C/CAPES TO 1000 J/KG/) TO DRIVE SOME WEAK CONVECTION IN BEST CONVERGENCE REGION OF FRNT FROM BALDWIN TO DURAND. SUPPOSE THERE COULD BE ENOUGH FOR AN ISOLD SVR EVENT VCTY KEAU THRU 23Z...BUT OVERALL INSTABILITY AND SHEAR NOT QUITE GREAT ENUFF FOR A MORE WIDESPREAD SVR RISK...DESPITE STRONG FORCING BOTH ALOFT IN RRQ OF JET AND IN FRONTAL ZONE WITH AID FROM S/W TROFS. BUT RADAR WL BE WATCHED CLOSELY FOR ANY FURTHER DVLPMNT. WL KEEP WND ADVRY IN WCNTL/SCNTL PER CURRENT WIND GUSTS AND CLEARING MOVING IN. NOT SMASHING CRITERIA BY ANY MEANS...BUT ENUFF GUSTS AOA 45MPH TO KEEP ADVRY AS BEST PRES RISES MOV THRU PER RUC. XPECT RAINS TO FOCUS MORE ON WCNTL WI THIS EVE...AND DIMINISHED POPS AND WORDING TO THE WEST AS STRONG SUBSIDENCE TAKES OVR FM WEST TO EAST. WENT ABV GUIDANCE MOST AREAS DUE TO WINDS AND AMPLE RAINS OF TDY. TUE/TUE NIGHT WL BE QUIET AND COOL...AS UNSEASONABLY STRONG SFC HI PRES MOVS RIGHT OVR CWA. SOME MIXING WINDS IN THE ERN CWA SHUD YIELD SOME GUSTS...AND REMNANT LL MOISTURE FIGURES TO POP SOME CU PER CU FORMATION RULES. AWFULLY COLD ALOFT...WITH H85 TEMPS HOVERING >5C. WENT MORE WITH MAV (WARMER) TEMPS GIVEN IT IS LATE MAY AND ANY SUN CAN WARM TEMPS INTO THE 60S PRETTY EASILY. RECENT RAINS/LIGHT WINDS/COLD TEMPS/CLEAR SKIES SPELLS FOR SOME GUD RADIATION FOG FORMING IN AREAS TUE NIGHT...ESP ERN CWA NEAR RIDGE AXIS. WED/WED NIGHT...NICE LITTLE WAVE SPILLS OVR BUILDING WRN RIDGE AND DROPS INTO DEVELOPING ERN CONUS TROF WED NIGHT. PRETTY DECENT PV ANOMALY WITH WAVE GIVEN NICE H25 80KT JETLET AND LAYER DIVERGENCE. MOISTURE WRAPPING ARND BACKSIDE OF BIG SFC HI WILL BE MEAGER BUT ENOUGH ALOFT TO DRIVE SOME WAA ACCAS AND SHRA. THIS PLODS ALONG THRU CWA WED AFTN AND EVENING. RIGHT ON ITS HEELS A BIGGER S/W HELPS CARVE OUT ERN TROF...AND BEGINS TO HELP CLOSE OFF CIRCULATION OVR GREAT LAKES. DISAGREEMENT HERE IN MDLS ON WHERE CLOSED CIRC WL DEVELOP...BUT ALL GUIDANCE SUGGEST THIS WILL BE A LARGE/COLD/CLOSED CIRC. WITH STRONG NEG HEIGHT AND TEMP ANOMALIES. SUBSEQUENT SHOWER CHANCES HINGE GREATLY ON THIS CIRCULATION'S LOCATION. WENT MORE MIDDLE OF THE ROAD...WITH BEST CHANCES THUR AND FRI...AND IN THE SOUTHEAST SAT. LOW CONFIDENCE HERE. .MSP...WIND ADVISORY THRU 6 PM SOUTH AND WEST OF A LINE FROM KAXN TO KAEL. $$ BINAU mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 300 PM CDT MON MAY 19 2003 MAIN FOCUS FOR THE SHORT TERM IS FLOODING POTENTIAL. THE STRONG COLD FRONT CONTINUES TO MARCH SLOWLY EASTWARD THIS AFTERNOON...WITH CONSIDERABLE FRONTAL AND PRE-FRONTAL RAIN. SOME THUNDERSTORMS HAVE JUST CROPPED UP IN THE UNSTABLE AIR IN NW WI. MSAS INDICATES -2C LI POKING INTO NW WI...WHICH IS IN LINE WITH THE LATEST RUC FORECAST. THE RUC POINTED TO THIS AREA NICELY THIS MORNING...SO WILL USE IT FOR THE SHORT TERM. WILL USE THE ETA FOR THE LONGER TERM...AS AVN APPEARS TO BE WAY TOO HEAVY ON QPF FOR THURSDAY. CANADIAN AGREES WITH ETA. THE BIG PROBLEM FOR TONIGHT WILL OBVIOUSLY BE THE FLOOD POTENTIAL IN NW WI. THE FRONT CONTINUES TO CHUG SLOWLY OFF TO THE EAST...BUT WITH SOME TRAINING POTENTIAL AHEAD OF THE FRONT WE WILL KEEP THE FLOOD WATCH GOING FOR THE NIGHT. PRECIPITABLE WATER VALUES HOVER AROUND 1.6 INCHES THROUGH THIS EVENING... SO CANNOT RULE OUT SOME PROBLEMS WITH RIVERS...STREAMS AND FULL DITCHES AND CULVERTS. THE MOS GUIDANCE HAS BEEN HINTING AT SIGNIFICANT CLEARING FOR THE PAST FEW MODEL RUNS...BUT WE WILL BE A LITTLE MORE CONSERVATIVE GIVEN THE UPPER TROUGH AND VORT MAX MOVING OUT OF THE FAR NORTHERN PLAINS. THERE COULD BE A PERIOD OF CLEARING...BEFORE THE CLOUDS NEAR THE VORT AND UPPER TROUGH MOVE IN. THE GROUND WILL ALSO BE WET FROM TODAY'S RAINFALL...SO THAT WILL SLOW DOWN THE CLEARING. DON'T THINK FROST WILL BE A WIDESPREAD PROBLEM TONIGHT DUE TO SOME WIND. THINK THE MORE SIGNIFICANT FROST POTENTIAL WILL BE TUESDAY NIGHT. OUR OFFICE HAS NOW BEGUN TO ISSUE FROST AND FREEZE HEADLINES FOR THE SEASON...AND A FROST ADVISORY MAY BE NEEDED FOR TUESDAY NIGHT IF THINGS COME TOGETHER AS EXPECTED. MOS TEMPS ARE QUITE VARIED. HAVE WENT ON THE COOLER SIDE FOR THE NIGHTTIME TEMPS...AND ALSO FOR THE DAYTIME TEMPS ON WEDNESDAY. .DLH...FLOOD WATCH WIZ001>004-006>009. $$ DAP mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 335 PM CDT MON MAY 19 2003 ...MAIN FORECAST CONCERNS ARE THUNDERSTORM CHANCES TONIGHT AND TEMPERATURES TUESDAY NIGHT... THIS AFTERNOON'S WATER VAPOR IMAGERY SHOWED SHORTWAVE ENERGY TRACKING ACROSS THE NORTHERN PLAINS...THIS FEATURE HELPED TO DRAG A COLD FRONT INTO CENTRAL PORTIONS OF KANSAS AND OKLAHOMA. IN ADDITION...UPPER LEVEL DIFFLUENCE WAS NOTED ACROSS MUCH OF MISSOURI. CONVECTION WAS FIRING BOTH IN ADVANCE AND BEHIND THE FRONT ACROSS NORTH-CENTRAL AND NORTHEAST KANSAS. THIS CONVECTION DEVELOPED IN A REGION OF STRONG 1000-850 MB F-VECTOR CONVERGENCE. NO SHOWERS OR THUNDERSTORMS HAVE AFFECTED THE FORECAST AREA SO FAR TODAY. THE 12Z SOUNDING AT SGF SHOWED A STRONG CAPPING INVERSION...THIS SUPPRESSED THE MORNING CONVECTION WHICH TRIED TO PUSH EAST OUT OF CENTRAL KANSAS. BOTH THE RUC AND MESOETA SHOW THIS CAP WEAKENING DURING THE LATE AFTERNOON/EARLY EVENING HOURS. IN ADDITION...19Z LAPS DATA SHOWED CAPE VALUES INCREASING IN EXCESS OF 1000 J/KG ACROSS SOUTHEAST KANSAS AND WESTERN MISSOURI WHERE SURFACE TEMPERATURES HAD RISEN INTO THE LOWER 80S. THE FRONT WILL PUSH INTO THE OZARKS THIS EVENING...WITH SHOWERS AND THUNDERSTORMS INITIALLY DEVELOPING ACROSS FAR EASTERN KANSAS AND WESTERN MISSOURI. QUITE STRONG 1000-850MB F-VECTOR FORCING WILL BE FOUND JUST BEHIND THE FRONT. WITH THIS IN MIND...CONTINUED THE ONGOING LIKELY POPS ACROSS THE WHOLE AREA. WITH MARGINAL INSTABILITY AND WEAK WIND SHEAR...THE SEVERE THREAT LOOKS TO BE LOW TONIGHT...WITH THE STRONGEST STORMS HAVING THE POTENTIAL TO PRODUCE PENNY TO NICKEL SIZE HAIL. SOME GUSTY NORTHERLY WINDS WILL BE FOUND BEHIND THE FRONT...BEGINNING LATE TONIGHT AND CONTINUING INTO TUESDAY. BUFKIT SOUNDINGS INDICATE GUSTS MAY APPROACH 30 MPH AT TIMES. A STRONG AREA OF HIGH PRESSURE SETTLES OVER THE REGION TUESDAY NIGHT INTO EARLY WEDNESDAY...CAUSING SKIES TO CLEAR AND WINDS TO BECOME NEARLY CALM. THIS SET UP IS VERY FAVORABLE FOR STRONG RADIATIONAL COOLING. IN ADDITION...A UNSEASONABLY COOL AIRMASS WILL BE IN PLACE. AT 06Z WEDNESDAY...850 MB TEMPERATURES ACROSS OUR NORTHERN COUNTIES WILL ONLY RANGE FROM 3 TO 4 DEG C. STAYED PRETTY CLOSE TO PREVIOUS FORECAST...WHICH WAS COOLER THAN YESTERDAY'S GUIDANCE. CONFIDENCE IS RISING IN THIS COLDER SOLUTION...AS 12Z MET GUIDANCE HAS TRENDED COOLER. IT GAVE LOWS IN THE UPPER 30S FOR AIZ AND VIH...DID NOT WANT TO GO THAT COLD YET...HOWEVER. RIGHT NOW I THINK RECORD LOWS ARE SAFE ACROSS MOST LOCATIONS...EXCEPT FOR PARTS OF CENTRAL MISSOURI. FORECAST LOWS WILL BE IN THE LOWER 40S ACROSS MUCH OF THE OZARKS...WITH MIDDLE 40S ACROSS FAR SOUTHERN MISSOURI. WITH GOOD RADIATIONAL COOLING...COOLER TEMPERATURES AND SCATTERED FROST COULD OCCUR IN VALLEYS AND LOW-LYING AREAS...THESE LOCATIONS MAY DROP INTO THE UPPER 30S. HERE ARE THE RECORD LOWS FOR WEDNESDAY... SGF 36 (1892) UNO 36 (1954) JLN 40 (1968) VIH 40 (2002) IN THE EXTENDED PERIOD DAYS 4 THROUGH 7 (THURSDAY THROUGH SUNDAY) THE GFS AND ECMWF ARE IN DECENT AGREEMENT THROUGH FRIDAY NIGHT. BOTH MODELS DEPICT NORTHWEST FLOW OVER THE OZARKS REGION AS AN UPPER RIDGE BUILDS OVER THE INTERMOUNTAIN WEST. MODELS BEGIN TO DIFFER BY SATURDAY MORNING WITH THE HANDLING OF SHORTWAVE ENERGY ACROSS THE UPPER MIDWEST. THE GFS PRODUCES A CUT-OFF LOW AND SHOWS THIS FEATURE DRIFTING OVER THE WESTERN OHIO RIVER VALLEY ON SATURDAY AND SUNDAY. IN CONTRAST...THE ECMWF KEEPS THE BULK OF THE ENERGY ACROSS CANADA AND THE GREAT LAKES REGION. ALL IN ALL...NOTHING CONCRETE IN THE LATEST DATA THAT WOULD INDICATE ADDING POPS TO THE FORECAST THROUGH SUNDAY...DID NOT CHANGE MUCH IN THE GOING GRIDS. $$ SAW mo