WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL 923 PM EDT WED MAY 22 2002 CURRENTLY...LATEST SFC ANALYSIS VIA MSAS SHOWS A 5-6MB GRADIENT FROM KMFL TO KJAX EARLY THIS EVENING. THIS TIGHT GRADIENT IS SUPPORTING BREEZY NELY WINDS ACROSS THE LAND AREAS WITH SMALL CRAFT CRITERIA BEING MET OVER THE OPEN GULF WATERS. 00Z RAOB DATA REVEALS A VERY DRY AND STABLE AIR MASS OVERHEAD SUPPORTING A VERY PLEASANT EVENING WITH MAINLY CLEAR SKIES WITH TEMPS IN THE 70S AND DEW POINTS IN THE 50S. REST OF TONIGHT...AN AREA OF CLOUDS AND SCATTERED SHOWERS WITHIN THE STRONG NELY FLOW CURRENTLY ALONG THE FL EAST COAST BETWEEN KDAB AND KMLB ARE PROGD BY THE MESO-ETA AND RUC TO ADVECT SWWD OVERNIGHT. HOWEVER GIVEN THE DRY STABLE AIR MASS OVERHEAD...AM EXPECTING MOST OF THESES CLOUDS/PRECIP TO ERODE AWAY AS THEY MOVE SOUTHWEST...SO ONGOING MOSTLY CLEAR WORDING STILL LOOKS IN GOOD SHAPE. DEW POINTS ARE RUNNING A BIT LOWER THAN GUIDANCE VALUES ACROSS MY NRN MOST ZONES AS I WRITE...SO I MAY NEED TO ADJUST MINS DOWN A BIT IN THESE AREAS. FOR NOW WILL MONITOR TEMP TRENDS A WHILE LONGER...AND DECIDE LATER THIS EVENING WHETHER AN UPDATE IS WARRANTED...OTHERWISE NO OTHER CHANGES EXPECTED. MARINE...ONGOING AND PROGD GRADIENT BY LATEST RUC/MESO-ETA SUPPORTS KEEPING SCA FLAGS IN PLACE OVERNIGHT. NO CHANGES EXPECTED IN THE 1030 PM UPDATE. .TBW...SMALL CRAFT ADVISORY BONITA BEACH TO SUWANNEE RIVER OUT 60NM INCLUDING TAMPA BAY. FIRE WEATHER WATCH THURSDAY AFTERNOON FOR THE COUNTIES OF LEVY...CITRUS...HERNANDO...AND SUMTER. RED FLAG WARNING THURSDAY AFTERNOON FOR THE COUNTIES OF PASCO...PINELLAS...HILLSBOROUGH...POLK...MANATEE...SARASOTA... HARDEE...DESOTO...HIGHLANDS...CHARLOTTE AND LEE. MCMICHAEL fl SOUTHWEST IDAHO/SOUTHEAST OREGON AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE IDAHO 930 PM MDT WED MAY 22 2002 NO UPDATES REQUIRED. COUPLE OF EVENING THUNDERSTORMS IN THE SRN HIGHLANDS HAVE DIED OUT WITH LOSS OF SFC WARM TEMPS AND WEAK RIDGING SFC AND ALF MOVING INTO OREGON, AND WEAK SHORTWAVE OVER NE CALIF AND N NV SLOWLY SHIFTS ESE. FURTHER N, WRAP AROUND MOISTURE AND SPOKES OF SHORTWAVE ENERGY OVER ERN WASHINGTON IDAHO AND MONTANA ROTATE S TONIGHT TO KEEP SCT NRN MTN SHOWERS GOING TONIGHT FOR NRN MTNS WHILE MID/HIGH CLOUDS SPILL OUT INTO THE SRN VALLEYS AT TIMES TONIGHT AS IN LATEST RUC40 AND ZONES PACKAGE. WINDS ALSO DIMINISHING DOWN TO 5-15 RANGE EXCEPT AROUND 15 OVER IN THE MAGIC VLY AND SE AREAS, IS COVERED WELL IN CURRENT PACKAGE. OF INTEREST IS STRONGER SHORTWAVE APPROACHING 50N 130W WHICH STARTED GETTING BETTER ANALYZED WITH THE 18Z MESOETA RUN...WHICH CROSSES MAINLY TO OUR NORTH LATE TONIGHT AND FRIDAY. UPPER WAVE EXPECTED TO COMBING WITH LINGERING MOISTURE IN THE CENTRAL MTNS ZONE TO KICK OFF MORE SHOWERS THURSDAY SO MID SHIFT MAY WANT TO KEEP SCT SHOWERS IN ALL DAY. 18Z MESO WAS ABOUT 60M LOWER THAN 12Z RUNS OVER SE WASH BLUE MTNS THURS. /VM .BOI...NONE. id AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1020 PM EDT WED MAY 22 2002 FCST CONCERN IS -SHRA/TS OVRNIGHT. 00Z WV LOOP SHOWED UPR MI IN SW FLOW ALOFT...WITH AN UPR LOW TO THE W OVR WRN ND. DRY SLOT APPARENT FROM N AZ INTO N MN WITH A 100 KNOT JET AT 300 MB IMBEDDED IN IT PER 00Z SNDG AT ABR. AT THE SFC AT 02Z...A 995 MB LOW WAS LOCATED NR JMS WITH MULTIPLE BOUNDARIES EXTENDING FROM IT; A STATIONARY FRONT TO JAMES BAY...A DRY LINE ARCED TO CNTRL NE...AND A COLD FRONT TO PIR AND WRN NE. VIS SATL IMAGERY AT 00Z SHOWED CI SPREADING ACROSS UPR MI...AHEAD OF WAA SCU FROM ERN MN/NW WI S INTO ERN KS. BASES OF THE SCU AROUND 4 KFT. BEHIND THIS WAA WAS SOME CNVCTN ON THE DRY LINE OVR N MN AND ERN NE/N KS. TRAJECTORIES FOR TNGHT COME FROM MSP FOR THE WRN/CNTRL U.P. AND FROM GRB FOR THE ERN U.P. BOTH 18Z ETA AND 21Z RUC SHOW THE WAA SCU IN ERN MN/NW WI CROSSING UPR MI...PRODUCING A FEW HUNDREDTHS OF QPF BTWN 03-06Z. CURRENT RADAR IMAGERY OUT OF DLH/MSP SHOWS SCT -SHRA OVR THE MN ARROWHEAD/NW WI/S CNTRL MSP WHICH HAVE BEEN MOVING TO THE ENE AROUND 30 KNOTS. NO SFC REPORTS OF -SHRA YET...MOST LIKELY DUE TO DRY AIR BLO 850MB ON 00Z SNDGS FROM MPX AND GRB. SO AT MOST THAT IS FALLING IS SPRINKLES. PRESENT VELOCITY WOULD BRING THE BACK EDGE OF IT ACROSS IWD BY 06Z AND CMX/IRON RIVER BY 08Z...AND WL PUT SIMILAR TIMING IN FCST. NOT TO EXCITED ABOUT TS GIVEN NO ELEVATED CAPE AND A MOIST ADIABATIC LAPSE RATE FROM 825 MB TO TROPOPAUSE ON 00Z MSP SNDG. WL REMOVE ALL MENTION OF TS AND -SHRA FOR CNTRL AND ERN U.P. SINCE -SHRA WL MISS THEM. ANOTHER INHIBITOR FOR RAIN TNGHT IS AN MCS DEVELOPING OVR ERN NE...WHICH SHOULD CUT OFF MOST OF THE MOISTURE COMING UP TO UPR MI. ALSO...DRY SLOT COMING INTO WRN CNTYS LATE TNGHT WL LEAD TO SOME CLEARING...AND WL MENTION IN FCST. CURRENT TEMPS STILL NR 70F AT IWD AND CMX...BUT GENERALLY IN THE 50S ELSEWHERE. WITH S TO SW WINDS FROM 15 TO 25 MPH AND HIGHER GUSTS ALL NIGHT AND CLOUDS MOVING IN...TEMPS SHOULD BE NEARLY STEADY. .MQT...NONE. AJ/KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 930 PM EDT WED MAY 22 2002 00Z SURFACE MAP SHOWS MAIN COLD FRONT OVER EASTERN NORTH DAKOTA TO CENTRAL NEBRASKA. AREA OF CONVECTION OUT AHEAD OF COLD FRONT DEVELOPING OVER NORTHWEST IOWA AND EASTERN NEBRASKA. ONE INTERESTING FEATURE IS A LAKEBREEZE CONVERGENCE ZONE FROM JUST WEST OF MARQUETTE SOUTH ALONG THE WESTERN LAKE MICHIGAN SHORELINE. RUC SHOWS SHORTWAVE IN VICINITY AT 00Z TO FURTHER SUPPORT THIS DEVELOPMENT. THIS HAS BROUGHT SOME LIGHT SHOWER ACTIVITY TO LAKE SUPERIOR AND THE CENTRAL U.P. WOULD EXPECT THIS AREA TO WEAKEN AND MOVE NORTHEAST AS LAKE BREEZE DIMINISHES AND SHORTWAVE SLIDES EAST. SOME MID CLOUD DEBRIS WILL OVERSPREAD FORECAST AREA BY MIDNIGHT. LIGHT SHOWER ACTIVITY IN ADVANCE OF THE SHORTWAVE MAY BRUSH THE EASTERN UPPER MICHIGAN ZONES AROUND MIDNIGHT IN ADVANCE OF THE DEEPER MOISTURE POISED TO MOVE INTO FORECAST AREA LATE. MAIN QUESTION IS HOW MUCH MOISTURE OR PRECIPITATION WILL BE ABLE TO PENETRATE THE DRY AIR OVER FORECAST AREA. WARM AIR AND MOISTURE ADVECTION SHOULD CONTINUE THROUGHOUT THE NIGHT...BUT NOT ENOUGH TO SUPPORT A HIGHER POP. PER CURRENT FORECAST...WILL KEEP LOW POPS OVER FORECAST AREA OVERNIGHT. LOW TEMPERATURES SEEM REASONABLE. WILL CHANGE WORDING TO THURSDAY NIGHT FORECAST FOR CLARITY. .APX...NONE. CAMPBELL mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1142 AM EDT WED MAY 22 2002 FCST CONCERNS ON UPDATE ARE WINDS AND TEMPS. WV IMAGERY/RUC ANALYSIS SHOWS STG SHRTWV/UPR LOW OVR LEE OF ROCKIES ROTATING SLOWLY EWD NUDGING AXIS OF BROAD UPR RDG SLIGHTLY EAST OF FA. AT THE SFC...HIGH PRESSURE WAS CENTERED OVER THE CNTRL APPALACHIANS WITH LOW PRESSURE OVR SE MT. SOME WAA CLDS FM MN/NW WI ADVANCING TOWARD WRN UPR MI FORMING AT NOSE OF 50 KT 850 MB JET AND REGION OF 3-5H DIFLUENCE/305K ISENTROPIC ASCENT. EXPECT THESE CLDS TO THIN OUT AS THEY SPREAD EAST THIS AFT INTO FA AND INTO DRIER AIR OF UPR RDG AS EVIDENT FM 12Z GRB SNDG. MAGIC MIXING HEIGHT FM AREA SNDGS YESTERDAY AT 00Z LOOKS TO BE AROUND 800 MB. DON'T BELIEVE THAT THIN CLDS SPREADING ACROSS FA THIS AFT WILL HAVE MUCH OF AN IMPACT ON THIS...SO WL KEEP GOING FCST OF 70 TO 75 FOR MOST LOCATIONS WHICH IS CONSISTENT WITH MIXING DRY ADIABATICALLY TO 800 MB PER 12Z SNDGS. MARINE LYR FM LAKE MICHIGAN IN SLY FLOW SHOULD KEEP INLAND TEMPS ANYWHERE FM 5-10F COOLER OVER ERN ZONES AND AROUND 20 DEGREES COOLER ALONG THE LAKE MI SHORELINE. 12Z GRB SNDG INDICATING WINDS TO 35 KTS WITHIN MIXED LYR SO KEEP HIGHER GUSTS TO 35 MPH IN THIS AFT...ESPECIALLY FOR FAVORED DWNSLPG SHORELINE AREAS ALG LAKE SUPERIOR. .MQT...NONE. VOSS mi AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY 600 PM MDT WED MAY 22 2002 THREW OUT A QUICK HIGH WIND WARNING THIS EVENING. 18Z RUC SUPPORTING HIGH WINDS THROUGH ABOUT 06Z...MAYBE EVEN A LITTLE LONGER IN THE EXTREME NORTHWEST. .UNR...HIGH WIND WARNING TONIGHT EXTREME NORTHWEST SOUTH DAKOTA WIND ADVISORY TONIGHT FOR THE PLAINS OF WESTERN SOUTH DAKOTA HELGESON sd AREA FORECAST DISCUSSION FOR CENTRAL/N-EAST SD AND W-CENTRAL MN NATIONAL WEATHER SERVICE ABERDEEN SD 345 PM CDT WED MAY 22 2002 MAIN FORECAST CONCERNS FOR TONIGHT INCLUDE WINDS AND CHANCES FOR CONVECTION ACROSS EASTERN CWA. ETA AND AVN MUCH MORE SIMILAR IN TERMS OF PLACEMENT AND STRENGTH OF UPPER WAVE OVER NORTHERN PLAINS. EVEN OUT TO 36 HOURS...ETA SEEMS TO HAVE COME AROUND TO THE AVN SOLUTION OF TENDING TO HOLD BACK NEGATIVE HEIGHT ANOMALIES WEST OF CWA INTO THURSDAY. ETA/AVN SOLUTION IN TERMS OF UPPER WAVE ALSO FAIRLY SIMILAR TO ECMWF AND CANADIAN. CONVECTIVE CHANCES LOOK BEST NORTH AND EAST OF CWA. 19Z LAPS DATA SHOWING BEST LOW LEVEL SURFACE MOISTURE AXIS EXTENDING ACROSS FAR EASTERN CWA WITH SURFACE BASED CAPES IN THE 600-800 J/KG RANGE JUST WEST OF THE MOISTURE AXIS. EVEN ACROSS EASTERN CWA FEEL THAT CHANCES FOR CONVECTION WILL BE MINIMAL WITH STEEPEST LOW AND MID LEVEL LAPSE AND LARGEST SURFACE BASED CAPES BEING QUICKLY ACCOMPANIED BY DRAMATIC BOUNDARY LAYER DRYING. LOW AND MID LEVEL THETA-E ADVECTION ALSO NOW SHIFTING EAST OF CWA. GIVEN CURRENT LAPS ANALYSIS OF FAIRLY STRONG MOISTURE FLUX CONVERGENCE WILL MAINTAIN THUNDERSTORM WORDING ESPECIALLY THIS EVENING. OTHER CONCERN FOR THIS EVENING WILL BE WINDS. RUC DATA SUGGESTING MAINTENANCE OF 30-35 KNOT 925 HPA WINDS AND DO NOT FEEL WILL FALL BELOW ADVISORY CRITERIA UNTIL AFTER DIMINISHED MIXING AFTER SUNSET. WILL EXTEND WIND ADVISORY ACROSS ENTIRE CWA UNTIL 01Z. MID LEVEL PVA SHOULD PROMOTE RETURN OF HIGH CLOUDS INTO REGION SO WILL GO FOR PARTLY CLOUDY WORDING TONIGHT. FOR THURSDAY...AM CONCERNED ABOUT MAINLY AM WINDS. MAIN SURGE OF COLD ADVECTION KICKS IN WESTERN CWA IN 12Z-14Z TIME FRAME AND SPREADS EASTWARD. ETA 3 HOUR PRESSURE RISES OF 4-6 HPA/3HR AND COLD ADVECTION PATTERN SHOULD ALLOW FOR BRIEF PERIOD OF 20 TO 30 MPH WINDS IN THE AM ACROSS NORTHERN AND EASTERN CWA...BEFORE DIMINISHING IN THE AFTERNOON. VERY STRONG UPPER DEFORMATION FOR TOMORROW AFTERNOON AS TROPOPAUSE LEVEL PV ANOMALY CONTINUES TO LOSE ITS INTEGRITY. WILL REMOVE THUNDERSTORM WORDING AND MENTION SHOWER POSSIBILITY FOR TOMORROW AFTERNOON ACROSS NORTHERN CWA...IN CLOSER PROXIMITY TO UPPER DEFORMATION AND UPPER DIVERGENCE AXIS. UNFORTUNATELY IT LOOKS AS THOUGH THURSDAY NIGHT MAY BE ANOTHER TIME FOR FROST CONCERN. SURFACE PRESSURE GRADIENT QUICKLY WEAKENS WITH COLD LOW LEVEL AIR STILL IN PLACE. FEEL THAT FREEZING TO SLIGHTLY SUB-FREEZING TEMPERATURES WILL BE LIKELY ESPECIALLY ACROSS NORTHWEST CWA. FRIDAY AND SATURDAY LOOK TO BE DRY WITH GENERAL MODEL CONSENSUS TO TAKE WEAK SHORT WAVE NORTH OF CWA FROM FRIDAY INTO SATURDAY. AVN/ECMWF SOLUTIONS SLIGHTLY MORE PROGRESSIVE THAN THE ETA WITH THIS WAVE...BUT IMPACT ON CWA SHOULD BE MINIMAL WITH ONLY WEAK UPPER FORCING. .EXTENDED DISCUSSION... MEDIUM RANGE MODULES STILL IN GENERAL AGREEMENT...IN THE BROAD SENSE. RIDGING CONTS TO BREAK DOWN WITH SW FLOW AT 5H AND 7H THROUGH THE HOLIDAY WEEKEND. MINOR WAVES MOVE THROUGH THE UPPER MIDWEST WHILE A SFC TROF APPEARS TO GET HUNG UP ACROSS THE REGION. SUNDAY WILL STILL BE DRY WITH PLEASANT TEMPS. RETURN FLOW SETS UP LATER ON SUNDAY WITH GOOD MOISTURE FEED RESULTING FROM GULF BEING OPEN. BY MONDAY DWPTS SHOULD BE IN THE MID TO UPPER 50S WITH GOOD LOLVL JET SETTING UP. WITH MAIN SFC CONVERGENCE LINE THROUGH OUR CWA ON MONDAY...APPEARS THAT CHANCE OF THUNDER STILL EXISTS...SO WILL LEAVE THAT ALONE. FOR TUESDAY...SFC TROF PUSHES SLOWLY EAST...ALLOWING HIGH PRESSURE TO BUILD IN. CANADIAN/ECMWF AND AVN ENSEMBLE MEANS ALL AGREE TO THIS. WILL END PCPN BY 18Z IN IFPS ON TUESDAY WITH DECREASE IN CLOUD COVER. BY WEDNESDAY BUILDING RIDGE TAKES OVER BRINGING DRY CONDS TO WARMING TEMPS BACK TO REGION. GUIDANCE TEMPS SEEM REASONABLE AND GENERALLY FOLLLOWED. .ABR...WIND ADVISORY ENTIRE CWA UNTIL 01Z. MARSILI/HINTZ sd AREA FORECAST DISCUSSION FOR CENTRAL/N-EAST SD AND W-CENTRAL MN...CORRECTED NATIONAL WEATHER SERVICE ABERDEEN SD 1140 AM CDT WED MAY 22 2002 TWO CONCERNS THIS AFTERNOON ARE WINDS AND CONVECTION CHANCES. RUC DATA SHOWING MID LEVEL LAPSE RATES INCREASING RAPIDLY ACROSS CWA THIS AFTERNOON AS MID LEVEL COLD ADVECTION WORKS EASTWARD. THE 15Z RUC STILL WITH WEST TO SOUTHWEST 925 HPA WINDS OF 35-40 KNOTS DURING THE AFTERNOON. ALTHOUGH BORDERLINE ADVISORY WINDS ARE LIKELY THIS AFTERNOON...HAVE ISSUED WIND ADVISORY FOR ENTIRE CWA THROUGH THE EARLY EVENING. CONVECTIVE POTENTIAL LOOKING A LITTLE LESS PROMISING AS TIME GOES ON. SURFACE OBSERVATIONS SHOW DEWPOINTS RAPIDLY BOTTOMING OUT WITH LOW LEVEL DRY AIR ADVECTION. SURFACE DEW POINTS IN KMBG AND KPIR NOW IN THE LOW AND MID 30S WITH EVEN LOWER DEWPOINTS UPSTREAM. EVEN WITH UPPER SUPPORT...THIS SHOULD LIMIT CONVECTIVE POTENTIAL THIS AFTERNOON WITH BEST CHANCES CONTINUING IN FAR EASTERN CWA. .ABR...WIND ADVISORY THROUGH 23Z FOR ENTIRE CWA. MARSILI sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 1005 AM EDT WED MAY 22 2002 A NICE DAY APPEARS TO BE HEADED OUR WAY...AS WARMING TREND JUST GETS STARTED TODAY. BNA 12Z SOUNDING WITH MIXING UP TO THE 800 MB LEVEL GETS MAX TEMPS INTO THE MID 60S OR SO. 12Z RNK SOUNDING WAS NOT VIEWABLE IN AWIPS. RUC MODEL RH FIELDS AND CU RULE SHOW POSSIBLE SCATTERED CUMULUS CLOUDS FOR NE HALF OF THE FORECAST AREA...WHERE THE FORECAST HAS MOSTLY SUNNY SKIES. OVERALL CURRENT FORECAST LOOKS FINE...BUT MAY DO A SLIGHT TEMPERATURE ADJUSTMENT FOR HIGHS TODAY FOR THE NE PLATEAU GROUP AND THE SRN MTN GROUP BASED ON YESTERDAY'S HIGHS. OTHERWISE...THE FREEZE WARNING SEEMS TO HAVE WORKED OUT QUITE WELL BASED ON OBSERVED MIN TEMPS THIS MORNING FROM ASOS AND COOP SITES. ANOTHER RECORD SETTING MORNING FOR TRI CITIES REGIONAL AIRPORT! .MRX... NC...NONE. TN...NONE. VA...NONE. TG tn AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE LUBBOCK TX 617 PM CDT WED MAY 22 2002 SURFACE GRADIENT REMAINS STRONG OVER THE FORECAST AREA WITH A SURFACE LOW OVER SOUTHEAST COLORADO AND HIGH PRESSURE RIDGE OVER THE LOWER MISSISSIPPI VALLEY. 21Z RUC SHOWS SURFACE WINDS WILL REMAIN STRONG THROUGH THE EVENING HOURS. HAVE UPDATED THE FORECAST TO ACCOUNT FOR HIGHER WINDS THIS EVENING. .LUB...NONE. TINSLEY tx DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 240 PM CDT WED MAY 22 2002 SHORT TERM...PRESSURE GRADIENT HAS INCREASED ACROSS TEXAS THIS AFTERNOON WITH HIGH PRESSURE OVER THE EASTERN UNITED STATES AND LOW PRESSURE OVER WEST TX. A PACIFIC FRONT WAS DRAPED ACROSS THE CENTRAL U.S. INTO THE TX PANHANDLE AHEAD OF THE 500MB TROUGH OVER THE WESTERN U.S. WATER VAPOR IMAGES AND RUC 1000-500MB STREAMLINE ANALYSIS INDICATED MOISTURE POOLING AHEAD OF THE FRONT ALONG THE BACKSIDE OF THE ANTICYCLONE CENTERED OVER THE MISSISSIPPI RIVER VALLEY. FURTHER SOUTH...700MB RIDGE OVER SOUTH TX HAS SHIFTED EASTWARD ALLOWING A FEW LINES OF CONVERGENCE OVER THE WESTERN GULF OF MEXICO TO REACH THE CWA. MSAS SURFACE ANALYSIS AND VISIBLE SATELLITE IMAGES INDICATE MOISTURE STREAMING NORTHWARD OVER CENTRAL TX WITH RETURN FLOW. CONVECTION TO DEVELOP OVER THE MIDWEST THURSDAY ALONG THE FRONT INTO THE CENTRAL PLAINS FRIDAY AS THE TROUGH OVER THE WESTERN U.S. MOVES THROUGH THE NORTHERN ROCKIES AND WEAKENS. WEAKNESS IN THE 700MB RIDGE OVER THE LOWER TX COAST MAY ALLOW SHOWERS OVER THE WESTERN GULF TO REACH EASTERN PORTIONS OF THE CWA SO WILL INCLUDE SLIGHT POPS ALONG THE COAST FOR NOW. OTHERWISE...NORMAL TEMPERATURES TO PERSIST WITH ONSHORE FLOW THE NEXT COUPLE OF DAYS. ALSO...BREEZY CONDITIONS EXPECTED DURING THE AFTERNOON WITH NOCTURNAL LOW LEVEL JET MIXING DOWN. EXTENDED...FRONTAL BOUNDARY OVER THE RED RIVER VALLEY NOT EXPECTED TO MOVE MUCH THROUGH THE WEEKEND WITH A MORE ZONAL FLOW DEVELOPING. CONVECTION APPEARS TO BE LIMITED TO NORTH TX SAT NIGHT INTO SUNDAY ALONG THE FRONT. 700MB RIDGING OVER NORTHEAST MEXICO INTO THE LOWER RIO GRANDE VALLEY APPEARS TO KEEP A LID ON CONVECTION. 700MB SHORTWAVE TROUGH OVER EASTERN NM/WEST TX MAY INITIATE CONVECTION OVER SOUTHWEST TX ALONG THE DRYLINE. WILL KEEP SLIGHT CHANCE OF TSTMS FOR FAR WEST PORTIONS OF DEEP SOUTH TX MEMORIAL DAY AND TUESDAY. OTHERWISE...NO SIGNIFICANT CHANCE OF RAIN IS EXPECTED THROUGH THE REMAINDER OF THE PERIOD. .MARINE...INCREASING SOUTHEAST WINDS IN COMBO WITH RETURN MOISTURE FEED WILL MERIT THE MENTION OF ISOLATED THURSDAY MORNING SHOWERS OFFSHORE. WARMER NEARSHORE WATERS ALSO ALLOWED SHOWERS TO MAKE IT INTO THE COASTAL COUNTIES THIS MORNING...BUT THE SHOWERS WERE SHALLOW AND PRODUCED MAINLY SPRINKLES...SO LOOKING FOR PRETTY MUCH THE SAME SCENARIO TOMORROW MORNING. OTHERWISE...WILL KEEP THE SCA UP FOR THE LAGUNA MADRE THROUGH EARLY THIS EVENING AS OBS ARE NEAR 20 KNOTS WITH SOME HIGHER GUSTS. MODERATE WINDS AND 5 FEET SEAS PREVAIL OFFSHORE...BUT WILL KEEP SCEC WORDING AS WINDS ARE EXPECTED TO PICK UP OFFSHORE WITH A LLJ. SEAS COULD THEN BUILD A FOOT OR SO TO NEAR SCA HEIGHT BY MORNING. THE MESOETA IS BACKING OFF FROM THE STRONGER WINDS IT FORECAST FOR OFFSHORE PREVIOUSLY. WWIII MODEL NOT EVEN CALLING FOR SCA SEAS OVER THE NEXT 4 DAYS...WITH THE HIGHER SEAS PROGGED TO DEVELOP IN THE EAST GULF NOT REALLY MAKING IT OVER TO THIS SIDE OF THE BASIN. THUS...SCA CONDITIONS FOR THE OFFSHORE WILL LIKELY BE LOW END TO MARGINAL IN THIS FORECAST. PRELIMINARY NUMBERS... BRO BB 072 088/072 089/074 00/00/00/00/00 HRL BB 071 090/071 091/073 00/00/00/00/00 MFE BB 071 092/071 093/073 00/00/00/00/00 RGC BB 069 094/069 095/071 00/00/00/00/00 SPI BB 076 084/076 084/076 00/10/00/10/00 SYNOPTIC...61/MARINE-AVIATION-MESO...54 INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO .BRO...SCA GMZ130. tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FORT WORTH TX 925 AM CDT WED MAY 22 2002 HAVE DECIDED TO ISSUE A WIND ADVISORY FOR REMAINDER OF TODAY...WITH UPDATED ZONES...UPDATED HWO...AND NPW TO BE ISSUED SHORTLY. DATA FROM 22/12Z KFWD RAOB...KFWS VAD PROFILE...AND RUC40 ALL SUGGEST 30-40 KNOTS AT TOP OF BOUNDARY LAYER THROUGHOUT THE DAY. DIURNAL MIXING WILL EASILY ALLOW FOR 20-30 MPH SURFACE WINDS...WITH HIGHER GUSTS POSSIBLE. 65/DD .FWD...WIND ADVISORY FOR ALL ZONES FOR REMAINDER OF TODAY. tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 855 PM EDT WED MAY 22 2002 WILL OPT TO UPDATE ZFP TO MAKE MOSTLY SOME MINOR CHANGES TO THE FIRST PERIOD. RIDGE OF HI PRESS TO BUILD ACRS THE FA TONITE...AND THEN OUT TO THE EAST OF THE REGION ON THU. STORM SYS AND ASSOCIATED CF TO MOVE INTO THE WRN GREAT LKS REGION ON THU. GOOD SFC PRESS GRADIENT TO DEVELOP ACRS THE FA ON THU. WK S/W TO MOVE ACRS THE NRN GREAT LKS REGION AND ONT TONITE. ANOTHER S/W TO MOVE UP ACRS THE GREAT LKS REGION ON THU. 21Z RUC SHOWS TEMPS TO GET DOWN INTO THE U30S-M40S TONITE WITH WINDS BECOMING W-SW AT 5-10 KTS. T1MIN TEMPS ARE IN THE 30S TONITE. FEW MINOR TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON THIS. FROST ADVISORY LOCATIONS ALREADY HIGHLITED LOOK OK AND WILL LET NPW STAND FOR THIS UPDATE. MID-LVLS (AND LOW-LVLS) TO BE DRY ACRS THE FA TONITE. RUC SHOWS SOME CIRRUS TO AFFECT A GOOD DEAL OF THE FA TONITE THOUGH. IR SAT PIX SHOW THESE HIR CLDS MOVING DOWN ACRS THE FA ATTM. RUC VSBYS ALSO HINTING AT FOG ACRS ERN VT BY LATER TONITE...BUT FEEL THAT TEMPS WON/T BE BOTTOMING OUT CLOSE ENUFF TO DEWPTS FOR THAT TO HAPPEN...SO WILL IGNORE. WILL JUST ADD A FEW CLDS TO THE OVRNITE FORECAST TO ACCOUNT FOR ANY HI CLDS ACRS THE FA. WK H85 WAA TO TAKE PLACE ACRS THE FA TONITE AND ON THU. SOME LOW-LVL MSTR ADVECTION TO TAKE PLACE ACRS THE FA ON THU...BUT LOW-LVLS TO REMAIN BASICALLY DRY THEN THOUGH. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA BY LATE ON THU. SOME MID-LVL MSTR MAY AFFECT THE ST LAW VLY BY LATE ON THU. FEW CLDS MAY MAKE IT INTO THE ST LAW VLY BY LATER IN THE DAY ON THU...BUT WILL LEAVE FORECAST FOR THEN ALONE FOR NOW. REST OF CHANGES TO GOING ZFP COSMETIC. WRK ZONES OUT UNDER ALBWRKCWF. FINAL ZFP BY 930 PM. .BTV...FROST ADVISORY OVERNITE NYZ029>031-034. MURRAY vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 217 PM CDT WED MAY 22 2002 FORECAST CONCERNS ARE FOR WINDS/STORMS THE NEXT 24 HOURS WITH FRONTAL PASSAGE AND BRIEF MOISTURE RETURN...THEN SATURDAYS POSSIBLE RAIN. WATER VAPOR DEPICTING THE SIGNIFICANT LOW PRESSURE SYSTEM OVER DAKOTA/MT BORDER AT 18Z WITH 500MB HEIGHT FALLS AT KUNR OF 180MB/12HR. THIS MONSTER IS SHIFTING EAST WITH THE STRONGEST WINDS NOW AT THE TROUGH BASE OR EAST OF IT. SURFACE DEWPOINTS HAVE RETURNED TO 50+F INTO ND AHEAD OF DRYLINE FROM KJMS-KABR-KHLC KS. MIDDLE 50S NOT TOO FAR SOUTH WITH SBCAPES NOW ABOUT 800J/KG ON THIS THIN AXIS AHEAD OF FRONT PER RUC. SIGNIFICANT CAP IN PLACE OVER MUCH OF THIS REGION HOWEVER PER RUC AND 12Z RAOB DATA. STRATOCU FILLING IN WHERE LCL IS LOWER THAN CAP AND THIS IS NEARLY OVERCAST. 12Z MODELS ARE SLIGHTLY DIFFERENT IN MOVING THIS SYSTEM EAST WITH THE AVN SLOWER WITH FROPA ACROSS AREA. THIS LOOKS MORE REASONABLE WITH CURRENT OBSERVATIONS...WILL GO WITH SLOWER TIMING. BOTH MODELS CONVECT ALONG FRONT IN MN/IA THIS EVENING WITH MARGINAL CAPES AROUND 1000 J/KG. WITH STRONG CAPPING IN PLACE...BELIEVE TSRA CHANCES WILL BE ALONG FRONT WITH WEAK CONVECTION DYING AS IT MOVES EAST AWAY FROM THIN SURFACE MOISTURE RIBBON AND FRONTAL CONVERGENCE. WILL KEEP CHANCE POPS TONIGHT. NO THREAT FOR SEVERE. THUS FAR WINDS ARE NOT AS HIGH AS FORECAST PREVIOUSLY AND ALTHOUGH LOW-LEVEL NEAR SURFACE WINDS ARE STRONG...WITH CAPPING AND NOT GOOD SUBSIDENCE AND DEEP MIXING TONIGHT...WILL EXPIRE ADVISORY IN WI. MODEL SOUNDINGS SEEM TO THINK A BIT OF DECOUPLING WILL OCCUR BEFORE CLOUDS MOVE IN. WILL MONITOR WIND SPEEDS OVER IA/MN AND I MAY KEEP THE SERN MN/NERN IA WIND ADVISORY TONIGHT BASED ON LATE AFTERNOON REPORTS. CLOUDS CURRENTLY OUT WEST SHOULD SHIFT EASTWARD WITH FRONT. THIS AND WINDS WILL MAKE FOR A WARM OVERNIGHT...5-7F ABOVE NGM GUIDANCE. THURSDAY THE FRONT WILL SHIFT THROUGH THE AREA. AS LOW MOVES EAST...IT WILL FILL/WEAKEN SO WINDS WILL BE MORE TAME THURSDAY BUT SOUTHERN AREAS WILL BE ABLE TO BUILD CAPES OF 1000J/KG WITH LATE FROPA EXPECTED THERE. LOW-LEVEL CLOUDS COULD CAUSE A PROBLEM BY LIMITING HEATING. IN ANY CASE...WILL KEEP CHANCE OF TSRA GOING AND TIME FRONT THROUGH TOMORROW. WARMEST HIGHS WILL BE SWRN WI. SCT CLOUDS AND STABLE WEATHER FRIDAY LEADS TO A DEVELOPING LOW OVER THE CENTRAL PLAINS FOR SATURDAY. THIS COULD SPREAD RAIN INTO SOUTHERN WI/NERN IA FOR SATURDAY. HAVE TRENDED TOWARD THAT SOLUTION IN PACKAGE WITH CLOUDS/CHANCE OF RAIN IN THE SOUTH. NEXT RAIN CHANCE THEN APPEARS TO BE TUESDAY. KDMX/KMPX COORDINATION ON WIND ADVISORY. THANK YOU. .LSE...NONE. BAUMGARDT wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 143 AM EST THU MAY 23 2002 SHORT TERM DISCUSSION... SFC ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER THE MID ATLANTIC COAST WITH LOW PRESSURE OVER NW MN AND COLD FRONT EXTENDING THROUGH E NE AND BACK TO SECOND LOW OVER W KS. SAT AND LIGHTNING DATA DEPICTING MCS OVER SW IA/SE NE ON NOSE OF STRONG 50-60KT LLJ OVER KS/OK WITH 5Z PROFILER READING OF 80KT AT HBRK1 IN KS. CURRENT 850- 300MB THICKNESS PATTERN SHOWS SW-NE ORIENTATION AND BECOMING DIVERGENT INTO E IA WITH RIDGE EXTENDING UP THROUGH IL AND LATEST RUC FCST SHOWS DIVERGENT PATTERN TO CONTINUE THROUGH 12Z SO ALTHOUGH PATTERN BECOMES MORE W-E AS RIDGE SHIFTS EAST...NOT ANTICIPATING ENOUGH EASTWARD PROGRESS OF THIS SYSTEM TO FACTOR INTO OUR WX FOR THIS MORNING. OVERALL PATTERN WILL SEE A FLATTENING OF UPPER RIDGE OVER THE MIDWEST INTO A MORE ZONAL PATTERN AS UPPER TROUGH OVER NORTHERN PLAINS OPENS UP AND MOVES EASTWARD ACROSS SOUTHERN CANADA. AS A RESULT...APPROACHING COLD FRONT WILL BECOME PARALLEL TO UPPER FLOW AS IT MOVES INTO THE AREA TONIGHT. THIS WILL MAKE TIMING AND CHANCES FOR PRECIP THE MAIN CHALLENGE THROUGH DAY 3. FRONT TO PROGRESS INTO E WI BACK THROUGH NW IL BY LATE TODAY. SFC HIGH OVER MID ATLANTIC REGION WILL DIVERT DEEPER GULF MOISTURE TO OUR W/SW AND WITH VIRTUALLY NO INSTABILITY AHEAD OF FRONT DO NOT EXPECT PRECIP TO REACH OUR AREA TODAY. PREVIOUS FCSTS HAVE CONSISTENTLY MENTIONED SMALL CHANCE FOR WESTERN HALF OF CWA HOWEVER SO WILL CONTINUE WITH THE 30 POP BUT WILL TRIM BACK TO WESTERN THIRD. PASSAGE OF FRONT TONIGHT WILL CONTINUE PRECIP CHANCES...BUT LACK OF DEEP MOISTURE AND UPPER SUPPORT WILL STAY WITHIN CHANCE CATEGORY. FRONT THEN STALLS JUST NORTH OF OH RIVER FRI. AVN AND ETA DIFFER SLIGHTLY ON TIMING OF SHORT WAVE RIDING UP FRONT WITH AVN BRINGING IT THROUGH FRI AFTN AND ETA CLOSER TO FRI NITE. GIVEN UNCERTAINTY OF TIMING WILL OPT TO STAY WITH CHANCE POPS BOTH FRI AND FRI NITE. SFC WAVE THEN MOVES UP AND THROUGH THE AREA ON SAT WHERE AVN AND ETA SEEM IN BEST AGREEMENT ON PRECIP. BUT FOR NOW WILL STAY WITH HIGH CHANCE RANGE FOR POPS. FWC/MAV CLOSE AND REASONABLE EXCEPT FOR HIGHS FRI WHERE COULD SEE UP TO 10 DEGREE RANGE FROM NW CWA TO SE DEPENDING ON WHERE FRONT ENDS UP. WILL PROBABLY GO WITH SOME TYPE OF BLEND OF WARMER FWC AND COOLER MAV. EXTENDED FORECAST... NOT MUCH CHANGE TO EXTENDED. KEPT MOSTLY CLOUDY SKIES MOST OF SUNDAY AS FRONT WILL STILL BE JUST EAST OF FORECAST AREA. HOWEVER SKIES CLEAR OUT SUNDAY NIGHT AS HIGH PRESSURE BUILDS IN. MONDAY AND TUESDAY LOOK GOOD WITH MOSTLY CLEAR SKIES AND SLOW WARMING TREND. TEMPERATURES SHOULD REACH NEAR NORMAL VALUES DURING THE DAY MONDAY AND STAY NEAR NORMAL THROUGH MID-WEEK. INCREASING CLOUDINESS ON WEDNESDAY SHOULD OFFSET ANY WARM AIR ADVECTION. .IWX...NONE. JAL/OHARA in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 127 AM EDT THU MAY 23 2002 VERY DYNAMIC SYS OVER NRN ROCKIES ATTM WITH NARROW PLUME OF HIGH SFC THETA-E OVER CENTRAL PLAINS. PER RUC80 500MB RIDGE SLOWLY MVG E OVER CWA WITH THIN CI SWEEPING SWD DOWNSTREAM OF RIDGE AXIS. DRY RESIDUAL AIRMASS OVER CWA TODAY AS COLUMN RH'S REMAIN LOW UNDER SUBSIDENT MID-LEVEL FLOW. WELL MIXED PM ATMOS TO 875MB SUGGESTS SFC WINDS MAY REACH 15-20KTS ESP OVER NRN KY/SRN IN...REFLECTED IN EXP 10KM MM5 SFC WINDS AT KSDF. WITH THIS MIXING TEMPS SHOULD WARM NICELY SO WILL LEAN TWD WARMER GUIDANCE MAXIMA (MID/UPPER 70S). TONITE AS FIRST 500MB WAVE MARCHES EWD INTO ONTARIO SFC TROUGH AXIS MOVES INTO CENTRAL IL/IN. APPEARS TO BE SOME FLAVOR OF MCS DVLPMT OVER KS/MO AFT 3Z/FRI ASSOC WITH NOSE OF 900MB LLJ. PER 850-500MB THICKNESS PATTN AND 850 TD AXIS...MCS WOULD LKLY PROPAGATE NEWD TO NEAR KSTL TOWARDS DAYBREAK FRI. BELIEVE PRIMARY EFFECT ON CWA WOULD BE INCR IN MID/HIGH LEVEL CLOUDS ESP OVER NRN ZONES THU NIGHT. WITH MORE CLOUDS MINIMA WILL INCR FROM PREVIOUS VALUES...SO MID/UPPER 50S WORKS FOR ME PER META/GUIDANCE COMPROMISE. FRI AFTERNOON FCST A BIT TRICKY FOR NRN COUNTIES. SFC TROUGH AXIS SAGS SWD INTO SRN IND AFTER 21Z/FRI BUT QUESTION WILL BE MOISTURE AND INSTABILITY. PER META 300/305K DATA OVERALL UPGLIDE/MOISTURE RETURN OVER CWA DOESN'T SEEM THAT GREAT BUT THERE WILL BE AN AXIS OF HIGHER PWATS ASSOC WITH SFC TROUGH ITSELF. THEN INTO THE MIX...A 2ND SYS EJECTING FROM ROCKIES BY 0Z/SAT WILL ACT TO THRUST FRONT BACK NWD OVER IN/IL. BUT GIVEN THAT MCS RESIDUE MAY BE NEARBY...AM INCLINED TO ADD 30% SHRA/TS TO NRN TIER OF SRN IND COUNTIES CONSISTENT WITH 21Z/22 ETA-ENS DATA. WITH A BIT OF 700MB SUBSIDENCE S OF FRONTAL ZONE...THINK KY ZONE MAXIMA WILL BREAK 80F. FRI NIGHT 2ND SFC LOW WILL PUSH FRONT FURTHER N...LEAVING CWA WITH SKC-BKN WEAK WAA MID/HIGH LEVEL CLOUDS. PER AVN SFC-LI FIELDS...COLD FRONT ASSOC WITH 2ND LOW MOVES THRU CWA LATE SAT AFTERNOON AND SAT NIGHT...BUT ONCE AGAIN THINK RESIDUAL DRY AIR WILL HOLD TO SOME EXTENT OVER CWA SO QPF TO BE CONFINED TO VERY NARROW BAND ALONG SFC FRONT. BUT WITH 700-500MB L/R'S ABV 7C/KM THUNDER A GOOD BET. NOTICED AVN PRODUCING WARM-CORE CYCLONE OFF SE COAST BY 12Z/MON. WILL BE INTERESTING TO SEE IF THIS OCCURS AND HOW IT WOULD INTERACT WITH THAT FRONT. .SDF...NONE. SMALLCOMB ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ST LOUIS MO 400 AM CDT THU MAY 23 2002 MCS PUSHING NEWD INTO IA N OF CWA...ALTHOUGH NEW DEVELOPMENT OVR NWRN MO MAY MOV INTO NERN MO LTR THIS MRNG. RUC ANLYS CONTS TO INDICATE STG 850 MB MOISTURE CNVG AND 800-600 MB WAA ACRS NERN KS SERN NEBRASKA ON NOSE OF 60-70 KT SWLY LLJ THRU CNTRL KS. ALTHOUGH MDLS SHOW LOW LVL WAA WKNG AS LLJ VEERS AND WKNS LTR THIS MRNG...OUTFLOW BOUNDARIES FM CONVECTION ACRS IA AND NWRN MO SHOULD PROVIDE FOCUS FOR SCT CONVECTION TO DVLP THIS AFTN MAINLY OVR NERN MO. ETA MDL DEPICTS STRENGTHENING UPR LVL DIVERGENCE OVR NERN AND CNTRL MO LTR TDA AND TGT IN RGT ENTRANCE REGION OF JT STRK MOVG NEWD THRU THE GRT LKS REGION. CDFNT DROPPING SEWD TO NR STL BY 12Z FRI...ALNG WITH RELATIVELY WK SHRTWVS AHD OF MAIN UPR TROF CURRENTLY OVR THE SWRN US SHOULD PROVIDE LOW AND MID LVL FRCG FOR A BETTER THREAT OF CONVECTION TGT...ALTHOUGH IT APRS THAT MOST OF THE HEAVIER PCPN WL BE OVR KS OK AND INTO SWRN MO ON NOSE OF LLJ AHD OF 850 MB LOW IN THE TX PNHDL REGION. MDLS SHOWING IMPRESSIVE LOW-MID LVL WAA IN THIS REGION. CDFNT WL STALL ACRS CNTRL MO ON FRI WITH BOTH ETA/AVN DVLPG A SFC WV ALNG FNT MOVG THRU NERN MO LT FRI NGT AHD OF MAIN UPR TROF. PCPN SHOULD FINALLY END BY SAT NGT AS UPR TROF AND ASSOCIATED SFC LOW WITH TRAILING CDFNT PUSH E OF THE CWA. LTR SHIFTS MAY NEED TO CONSIDER FLOOD WATCH FOR FRI AND FRI NGT WITH POTENTIAL OF HVY RAIN AS LOW-MID LVL MOISTURE AND INSTABILITY BCMS MORE IMPRESSIVE OVR MUCH OF THE CWA. .STL...NONE GKS mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 135 AM CDT THU MAY 23 2002 FORECAST CHALLENGES -- ONGOING CONVECTION AND THEN PRECIPITATION CHANCES FRIDAY/FRIDAY NIGHT SYNOPSIS -- LATEST KOAX REFLECTIVITY DATA SHOWED A LINE OF THUNDERSTORMS STRETCHED FROM S-CNTRL NEB INTO NWRN MO, SLOWLY LIFTING NWD. LATEST PROFILER DATA AND 23/03Z RUCII OUTPUT INDICATE THIS CONVECTION IS OCCURRING IN A ZONE OF LOW-LEVEL MOISTURE (PW VALUES OF 1.3 TO 1.5 INCHES) AND MASS CONVERGENCE (850 MB PROFILER WINDS OF 35 KTS AT FAIRBURY, NE AND 70-80 KTS AT HILLSBORO, KS). AT THE SURFACE, A COLD FRONT EXTENDED FROM WRN MN THROUGH CNTRL NEB INTO NWRN KS AS OF 06Z, WITH THE AXIS OF HIGHEST THETA-E VALUES FROM S-CNTRL KS, W OF P28, INTO S-CNTRL NEB, S OF THE HSI/GRI AREA. FORECAST -- IN THE SHORT TERM, THE MAIN FOCUS IS ON THE EVOLUTION OF THE ONGOING CONVECTION ACROSS OUR SRN ZONES. 23/03Z RUCII DATA SUGGESTS A CONTINUED INFLUX OF HIGH THETA-E AIR ALONG THE LOW-LEVEL JET AXIS THROUGH 12Z, AND CURRENT IR SATELLITE TRENDS INDICATE THAT THAT CONVECTIVE REDEVELOPMENT IS BECOMING ANCHORED OVER S-CNTRL NEB. UPSHOT IS THAT WE COULD SEE SOME AREAS OF LOCALLY HEAVY RAINFALL THIS MORNING. THE CONVECTION WILL ULTIMATELY DIMINISH LATER THIS MORNING AS THE COLD FRONT, CURRENTLY TO OUR NW, MOVES SEWD THRU THE AREA. CURRENT FORECAST HIGHS HAVE A GOOD HANDLE ON TEMPERATURES TODAY, SO WE WILL LEAVE AS IS. THE LATEST ETA HAS NOW IN BETTER AGREEMENT WITH THE AVN WITH RESPECT TO STRENGTH AND TIMING OF THE NEXT SHORTWAVE TO MOVE THROUGH THE AREA FRIDAY AFTERNOON/FRIDAY NIGHT. ISENTROPIC ASCENT OVER THE SURFACE RIDGE AXIS WILL INCREASE THROUGH THE DAY WITH THE BEST POPS ACROSS THE WRN ZONES. THE PRECIPITATION SHOULD END BY MIDNIGHT IN THE W, WITH A MENTION WARRANTED OVERNIGHT ACROSS THE ERN ZONES. LOW-LEVEL RIDGING WILL REMAIN IN PLACE THROUGH SATURDAY NIGHT, BEFORE ANOTHER BAROCLINIC ZONE BECOMES ESTABLISHED ACROSS THE NRN PLAINS ON SUNDAY. LATEST AVN GUIDANCE INDICATES WE WILL REMAIN IN THE WARM SECTOR INTO MONDAY, WITH THE BEST CHANCES OF PRECIPITATION TO OUR N. WE WILL TAKE A LOOK AT THE AVN EXTENSION WHEN IT ARRIVES AND MAKE ANY CHANGES TO THE EXTENDED IF NECESSARY. THANKS TO GID FOR COORDINATION! IF YOU HAVE COMMENTS ON THE NEW FORECAST DISCUSSION FORMAT...PLEASE E-MAIL THEM TO W-OAX.WEBMASTER@NOAA.GOV OR CALL DAVE THEOPHILUS AT 402-359-5166. .OMA...NONE. MEAD ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 915 AM EDT THU MAY 23 2002 SYNOPSIS: WATER VAPOR/RUC H5 COMPOSITE SHOWS SHARP UPPER TROUGH OFF E COAST & RIDGE AXIS FROM ERN GREAT LAKES TO WRN GULF. N-NELY FLOW ALOFT W/ AMPLE SUBSIDENCE ABOVE H85 PER LOCAL RAOBS. BROAD HIGH PRESSURE RIDGE EXTENDS FROM SRN NEW ENGLAND TO NRN GULF. CLUSTER OF ACTIVE CONVECTION S OF CUBA ASSOCIATED W/ WEAK SURFACE LOW. SKIES WERE CLEAR OVER THE CWFA W/ SOME LOW CLOUDS NOTED ALONG THE FL E COAST. MORNING TEMPS WERE NOT AS COOL AS THE PAST FEW DAYS AS E-NELY BOUNDARY LAYER WINDS MODIFY AIRMASS. PUBLIC FORECAST: INHERITED ZONES ON TRACK. NO CHANGES. FIRE WEATHER: NO CHANGES. MARINE: C-MAN OBS INDICATE WINDS HAVE DROPPED BELOW SCEC CRITERIA... HOWEVER BUOYS STILL FLIRTING W/ SCA. WILL LOWER SCEC NEAR SHORE & MAINTAIN SCA OFFSHORE FOR SEAS ON LATE MORNING UPDATE. OFFSHORE SCA WILL BE LIKELY BE LOWERED TO SCEC ON AFTN FCST PACKAGE. .AL...NONE. .GA...NONE. .FL...RED FLAG WARNING INLAND ZONES TODAY NOON TIL SUNSET. FIRE WEATHER WATCH INLAND ZONES FRIDAY AFTN. SCA OFFSHORE WATERS THIS AFTN. MAJ fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1220 PM EDT THU MAY 23 2002 FOCUS IS CONVECTION CHANCES FOR AFTN SFC CHART FM 16Z SHOWS QUITE A CONTRAST OF AIRMASSES PRESENT OVR UPR MS VALLEY. PRIMARY LOW PRESSURE RESIDES OVR YQT WITH 997MB PRESSURE. SHARP COLD FRONT ORIENTED DOWN WRN LK SUPERIOR INTO ERN MN WITH MID 50S DWPTS AHEAD AND 30S/40S BEHIND. SFC TEMPS ALREADY RISING INTO THE 70S OVER WRN HALF OF UPR MI BUT COOLER 50S/60S OVR ERN HALF DUE TO SW FLOW TRANSPORTING 40F DEGREE WATER TEMP CLIMATE OF LK MI INTO AREAS EAST OF MQT-ESC. DLH/GRB AND MQT RADARS ALL QUIET ATTM. VIS SAT SHOWING STRATUS OVR WI SCRAPING SRN ZONES OTHERWISE A MS AND BREEZY DAY IS FOUND ACROSS MICHIGANS UPPER PENINSULA. AFTN CONCERN IS CONVECTION INITIATION ALONG APPROACHING COLD FRONT. LOCAL WS ETA FM 00Z AND RUC DEPICT POOLING OF MID 50S DWPTS INTO WRN UPR THIS AFTN WITH ENHANCED SFC WIND/MOISTURE CONVERGENCE DEVELOPING AS WINDS SHIFT W JUST AHEAD OF COLD FRONT...SETTING UP CONTRAST OF BLYR DWPTS/TEMPS AS AIR BECOMES INCREASINGLY OFF WRN LK SUPERIOR. SURFACE BASED INSTABILITY IS MODERATE WEST OF MQT-IMT AS CAPES/LIFTED INDEX APPROACH 900J/KG AND -5C AHEAD OF FRONT. WS ETA SHOWING H7 COLD POOL RIGHT AHEAD OF SFC FRONT BOOSTING H85-H7 LAPSE RATES TO 7-7.5C/KM LEADING TO RAPID INCREASSE OF SBCAPES (RISING TO 1500J/KG WITH T/TD PARCEL OF 78/55). LIMITING FACTOR FOR DEEP CONVECTION IS LIMITED MOISTURE JUST ABOVE H85 THROUGH H5...RESULTING IN KIX MAXING OUT AT 25C AND PWATS FLIRTING WITH 0.75. DRY MID LEVELS SHOW UP ON 12Z MPX SOUNDING WITH H85 TD OF +1...COMPARED WITH GRB OF +9. CROSS SECTION OF THETA-E WITH HT ALSO SHOWS SHARP DECREASE IN VALUES WITH HT THROUGH H85 BUT WITH SHARP INCREASE THROUGH H7. OVERALL...SYNOPTIC WINDS ARE STRONG WITH 35-55KT FM H85-H7 SO EVEN THOUGH UNIDIRECTIONAL FLW FAVORS MULTICELLS AND MOISTENING IN SUB H85 LAYER FAVORS LOW TOPPED CONVECTION...POSSIBILITY IS THERE FOR DOWNDRAFTS WITH STRONGER STORMS TO TRANSPORT SOME OF THESE HIGHER WIND SPEEDS TO SFC IN GUSTS...HAVE MENTIONED THIS IN ZONES AND AS MAIN THREAT IN SPSMQT. RUC/WSETA 925-900MB RH FIELDS HAVE GOOD HANDLE ON LOWER LEVEL MOISTURE IN WI AND SHOW THIS SHIFTING EAST...DISSIPPATING THROUGH DAY. SO HAVE WENT WITH MS/PS SKIES FOR AFTN...FURTHER HELPING THE DESTABILIZATION CAUSE. .MQT...NONE. JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1005 AM CDT THU MAY 23 2002 WIDELY SCATTERED TO SCATTERED TSRA TO THE SOUTHWEST ARE CONTAINING TO DEVELOP AND MOVE NORTHEAST. LIFT FROM SHORTWAVE ACROSS FAR SW TEXAS SOUTHERN NM APPEARS IS PROVIDING LIFT FOR ELEVATED STORMS TO DEVELOP ABOVE CAP. 12Z RUC AND LATEST ETA SUGGEST THAT ACTIVITY WILL CONTINUE TO SPREAD NORTHEAST THROUGH THE LATE MORNING INTO THE AFTERNOON. MODEL SOUNDINGS...FOR WHAT THEY ARE WORTH...ALSO SUGGEST THAT STORMS MAY BECOME MORE SURFACE BASED GOING INTO THE AFTERNOON. MORE CLOUDS ACROSS SOUTHWEST AND INTO NORTH CENTRAL SECTIONS WILL ALSO LIMIT INSOLATION. HOWEVER...PARTS OF SOUTHWEST MAY BE ABLE TO CLEAR SOMEWHAT LATER TODAY. WILL UPDATE GRIDS AND ZONES SHORTLY TO INCREASE POPS AND ADJUST TEMPERATURES. SIX ---------- 630 AM CDT THU MAY 23 2002 IMPULSE MOVING NE FROM SW TX APPEARS TO HAVE MORE BITE TO IT THAN EARLIER THOUGHT. CLOUDS CONTINUE TO THICKEN AND SPREAD NE TOWARD CWA WHILE SHRA/TSRA DEVELOP AND MOVE NE FROM N OF SJT AND ABI. STORMS GETTING VERY CLOSE TO SW CORNER OF CWA ATTM. BASED ON ALL THIS...AND LATEST MESOETA/AVN/RUC ALL BREAKING OUT LIGHT PRECIP IN OR NEAR AREA BY 18Z...WILL UPDATE THIS MORNING TO ADD LOW POPS TO THE S FOR TODAY AND TO INCREASE CLOUD COVER MOST AREAS. 24 ------------ 320 AM CDT THU MAY 23 2002 IT LOOKS EVEN MORE DEFINITE THIS MORNING THAT AN MCS WILL DEVELOP OVER THE KS/OK BORDER FROM LATE THIS AFTERNOON OR THIS EVENING... INTO FRIDAY MORNING... THEN AGAIN FRIDAY EVENING. A COLD FRONT IS FORECAST TO HANG UP RIGHT ALONG THE BORDER... PROVIDING A GOOD FOCUS FOR CONVECTION... WHILE THE STORM SYSTEM TO THE WEST APPROACHES AND HELPS WEAKEN THE RATHER STRONG CAPPING INVERSION THAT IS OVER THE AREA NOW. ONCE THE STORMS DEVELOP THIS EVENING... CORFIDI VECTORS AND MODEL INDICATIONS LEAVE THEM ABOUT WHERE THEY FORMED FOR THE ENTIRE NIGHT. THIS COULD LEAD TO SOME VERY HEAVY RAINFALL AMOUNTS... ESPECIALLY IN THE NORTH-CENTRAL PART OF OKLAHOMA. WHILE RAIN IS PROBABLY QUITE WELCOME UP THERE... THIS MAY TURN OUT TO BE TOO MUCH OF A GOOD THING. THE CHANCE OF RAIN DROPS OFF VERY FAST TO THE SOUTH AS THE STRONG CAP SHOULD HOLD ACROSS CENTRAL AND SOUTHERN OKLAHOMA TONIGHT. FRIDAY AFTERNOON AND EVENING SPORTS A SIMILAR SCENARIO... EXCEPT THAT THE FRONT WILL BEGIN TO MOVE AS THE UPPER SYSTEM REACHES THE SOUTHERN PLAINS. THIS WILL AGAIN PROVIDE THE POSSIBILITY OF AN MCS... BUT A MORE PROGRESSIVE ONE THIS TIME AROUND. THERE SHOULD BE LESS OF A HEAVY RAIN THREAT WITH THIS ONE. SINCE THE CAP SHOULD HAVE ERODED ACROSS THE ENTIRE AREA BY FRIDAY NIGHT... THE CHANCE OF RAIN WILL EXTEND ALL THE WAY TO OUR SOUTHERN ZONES. HOWEVER... THE UNCERTAINTY OF CAP STRENGTH AND BOUNDARY POSITIONS IS SUFFICIENT TO LIMIT POPS TO ABOUT 50 PERCENT OR LESS. SINCE THE EXACT OUTCOME OF ALL THE MCS ACTIVITIES WILL HAVE A MAJOR IMPACT ON PRECIPITATION CHANCES AND POSITIONS FOR THE WEEKEND... IT SEEMS BEST TO LET LATER SHIFTS REFINE THE WEEKEND FORECAST... AND THE FORECAST FOR EARLY NEXT WEEK. FCSTID = 23 = CMS OKC 81 63 77 56 / 20 30 40 50 HBR 85 63 78 56 / 20 30 30 50 SPS 85 66 83 63 / 10 20 10 50 GAG 83 58 73 51 / 30 80 60 30 PNC 81 60 73 52 / 30 80 60 40 DUA 79 66 78 64 / 0 10 10 50 .OUN... OK...NONE. TX...NONE. ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 630 AM CDT THU MAY 23 2002 IMPULSE MOVING NE FROM SW TX APPEARS TO HAVE MORE BITE TO IT THAN EARLIER THOUGHT. CLOUDS CONTINUE TO THICKEN AND SPREAD NE TOWARD CWA WHILE SHRA/TSRA DEVELOP AND MOVE NE FROM N OF SJT AND ABI. STORMS GETTING VERY CLOSE TO SW CORNER OF CWA ATTM. BASED ON ALL THIS...AND LATEST MESOETA/AVN/RUC ALL BREAKING OUT LIGHT PRECIP IN OR NEAR AREA BY 18Z...WILL UPDATE THIS MORNING TO ADD LOW POPS TO THE S FOR TODAY AND TO INCREASE CLOUD COVER MOST AREAS. 24 ------------ 320 AM CDT THU MAY 23 2002 IT LOOKS EVEN MORE DEFINITE THIS MORNING THAT AN MCS WILL DEVELOP OVER THE KS/OK BORDER FROM LATE THIS AFTERNOON OR THIS EVENING... INTO FRIDAY MORNING... THEN AGAIN FRIDAY EVENING. A COLD FRONT IS FORECAST TO HANG UP RIGHT ALONG THE BORDER... PROVIDING A GOOD FOCUS FOR CONVECTION... WHILE THE STORM SYSTEM TO THE WEST APPROACHES AND HELPS WEAKEN THE RATHER STRONG CAPPING INVERSION THAT IS OVER THE AREA NOW. ONCE THE STORMS DEVELOP THIS EVENING... CORFIDI VECTORS AND MODEL INDICATIONS LEAVE THEM ABOUT WHERE THEY FORMED FOR THE ENTIRE NIGHT. THIS COULD LEAD TO SOME VERY HEAVY RAINFALL AMOUNTS... ESPECIALLY IN THE NORTH-CENTRAL PART OF OKLAHOMA. WHILE RAIN IS PROBABLY QUITE WELCOME UP THERE... THIS MAY TURN OUT TO BE TOO MUCH OF A GOOD THING. THE CHANCE OF RAIN DROPS OFF VERY FAST TO THE SOUTH AS THE STRONG CAP SHOULD HOLD ACROSS CENTRAL AND SOUTHERN OKLAHOMA TONIGHT. FRIDAY AFTERNOON AND EVENING SPORTS A SIMILAR SCENARIO... EXCEPT THAT THE FRONT WILL BEGIN TO MOVE AS THE UPPER SYSTEM REACHES THE SOUTHERN PLAINS. THIS WILL AGAIN PROVIDE THE POSSIBILITY OF AN MCS... BUT A MORE PROGRESSIVE ONE THIS TIME AROUND. THERE SHOULD BE LESS OF A HEAVY RAIN THREAT WITH THIS ONE. SINCE THE CAP SHOULD HAVE ERODED ACROSS THE ENTIRE AREA BY FRIDAY NIGHT... THE CHANCE OF RAIN WILL EXTEND ALL THE WAY TO OUR SOUTHERN ZONES. HOWEVER... THE UNCERTAINTY OF CAP STRENGTH AND BOUNDARY POSITIONS IS SUFFICIENT TO LIMIT POPS TO ABOUT 50 PERCENT OR LESS. SINCE THE EXACT OUTCOME OF ALL THE MCS ACTIVITIES WILL HAVE A MAJOR IMPACT ON PRECIPITATION CHANCES AND POSITIONS FOR THE WEEKEND... IT SEEMS BEST TO LET LATER SHIFTS REFINE THE WEEKEND FORECAST... AND THE FORECAST FOR EARLY NEXT WEEK. FCSTID = 23 = CMS OKC 81 63 77 56 / 20 30 40 50 HBR 85 63 78 56 / 20 30 30 50 SPS 85 66 83 63 / 10 20 10 50 GAG 83 58 73 51 / 30 80 60 30 PNC 81 60 73 52 / 30 80 60 40 DUA 79 66 78 64 / 0 10 10 50 .OUN... OK...NONE. TX...NONE. ok AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE FORT WORTH TX 1021 AM CDT THU MAY 23 2002 MAIN SHORT TERM FORECAST CONCERNS ARE WINDS AND AFTERNOON SKY COVER. LATEST RUC/ETA SUGGEST THAT THE LOW LEVEL JET WILL WEAKEN THIS AFTERNOON WHICH SHOULD KEEP AREA JUST BELOW WIND ADVISORY CRITERIA. HAVE DECIDED TO MAINTAIN PARTLY CLOUDY WORDING FOR THIS AFTERNOON... ALTHOUGH THIS COULD BE A BIT OPTIMISTIC. STRATOCUMULUS DECK IS FILLING IN BUT LACK OF HIGH CLOUDS ABOVE THE LOWER DECK WILL ALLOW FOR SOME SUNSHINE TO BREAK THROUGH. HAVE ADJUSTED TEMPERATURES DOWN A CATEGORY MOST AREAS WITH A LITTLE MORE CLOUD COVER ANTICIPATED. LOW POPS IN THE NORTHWEST STILL LOOK GOOD GIVEN THE ELEVATED SHOWERS/THUNDERSTORMS CURRENTLY GRAZING THE AREA. .FWD...CAUTION IS ADVISED ON AREA LAKES. 9 tx SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 415 PM EDT THU MAY 23 2002 H2O VAPOR LOOP SHOWS LONG WAVE POSITIVE TILT TROF OVER THE WESTERN HALF OF THE CONUS WITH TWO DISTINCT SHORT WAVE TROFS...ONE PUSHING ACROSS THE NORTHERN PLAINS AND OTHER ACROSS THE FOUR CORNERS. PLUME OF THETA-E RACING NORTH ACROSS THE SOUTHERN PLAINS HEADING INTO THE UPPER GREAT LAKES. SFC ANALYSIS HAS LOW POSITION IN LAKE SUPERIOR WITH TRAILING COLD FRONT EXTENDING SOUTHWEST ACROSS WISCONSIN INTO THE SHOW-ME-STATE AND FINALLY INTO KANSAS. ACCAS OVERHEAD WITH 88D MOSAIC DEPICTING SOME STORMS ACROSS ILLINOIS AND SOUTHERN LAKE MICHIGAN. MODELS... NOT OVERLY CONFIDENT WITH SOLUTIONS THIS RUN DESPITE GOOD INITIALIZATION. THE ETA-XX APPEARS TO HAVE THE BEST HANDLE (INCLUDING THE EXTENDED) WITH NEW RUC20 DOING NICELY FOR THE 12HR FORECAST. THIS WILL HAVE SEVERAL CHANGES WITHIN THE PRESENT FORECAST. TONIGHT... IT APPEARS WE WILL NEED TO CUT BACK POPS A LOT. WHILE THETA-E RIBBON WILL BE MOVING OVERHEAD WITH DECENT 850-500 LAYER Q-VECTOR CONVERGENCE AND SURFACE CONVERGENCE INCREASING THIS EVENING...HOURLY RUC SOUNDINGS ARE STILL QUITE DRY. THIS IS QUITE EVIDENT WITH STORMS THAT DID FIRE ACROSS NORTHERN ILLINOIS (OLD MCS FROM EARLY THIS MORNING) HAVE WEAKENED QUITE A BIT. FROPA OCCURS NEAR 06Z ACROSS THE NORTH...AND BETWEEN 10-12Z SOUTH. WE WILL THEREFORE BRING POPS BACK TO /SCATTERED SOUTH/CHANCE NORTH/ WITH TEMPS CLOSE TO ETA MOS AND MAV. FRIDAY... TREND OF THE PAST SEVERAL RUNS IS FOR AN MCS THAT IS UNDERWAY ACROSS KANSAS TO HEAD NORTHEAST WHICH WILL IMPEDE THE PROGRESS OF THE FRONT. THE FRONT WILL BECOME QUASI-STATIONARY SOUTH OF THE MICHIGAN STATE LINE WHICH BRINGS THE CHANCE OF RAIN FURTHER NORTH ACROSS THE SOUTHERN COUNTIES. MEANWHILE...SFC HIGH BUILDS SOUTH ACROSS THE UPPER GREAT LAKES WITH MEAN RH FIELDS DROPPING OFF TO LESS THAN 30%. SKIES SHOULD BECOME PTSUNNY ACROSS THE NORTH ALTHOUGH CLOUDS WILL LIKELY HANG ON TOUGH ACROSS THE SOUTH. TEMPS COMPARED TO UPSTREAM CONDITIONS...LOOK CLOSE TO THE MAV AND ETA MOS VALUES. FRIDAY NIGHT... NEXT WAVES EJECTS INTO THE PLAINS STATES WITH SFC FRONT LIFTING NORTH AS A WARM FRONT. THIS WILL BRING THE CHANCE OF PRECIP BACK INTO THE SOUTHERN COUNTIES. THETA-E ADVECTION AND MOISTURE TRANSPORT VECTORS QUICKLY BRING BACK THE MOISTURE FOR MORE SHOWERS AND THE POTENTIAL FOR ELEVATED THUNDER. SATURDAY... FOR THE HOLIDAY WEEKEND...THIS IS SHAPING UP TO BE THE MOST ACTIVE WEATHER DAY. MODELS CONTINUE TO DISAGREE WITH TRACK OF THE LOW WITH THE ETA THE FURTHER NORTH...FOLLOWED BY THE GEM...ETA-XX...AVN THE FURTHEST SOUTH. AFTER READING NCEP DISCUSSION...WOULD HAVE TO LEAN TOWARD THE AVN AND LOCALLY PRODUCED ETA-XX WITH TRACK OF LOW NEAR THE BORDER. THIS SHOULD BRING ANOTHER ROUND OF RAIN TO THE CWA WITH THE CHANCE FOR THUNDERSTORMS. IF THE ETA IS CORRECT...WE HAVE THE POTENTIAL TO HAVE AN ACTIVE DAY WITH CAPES NEAR 1500 J/KG AND HODOGRAPHS SHOWING SOME CURVATURE FROM 0-3KM WITH HELICITIES IN THE LOWER 100S. EITHER WAY...LIKELY POPS WITH RRQ OF 300MB JET PROVIDING ADDITIONAL LIFT FOR RAIN. SATURDAY NIGHT INTO SUNDAY... SFC HIGH BUILDS ACROSS THE STATE WITH SOME FOG TO START THE DAY SUNDAY. OTHERWISE TRANQUIL CONDITIONS WITH 850 TEMPS ON THE CLIMB...SFC TEMPS RESPOND NICELY. EXTENDED... MODELS COMING AROUND TO A SOLUTION FOR AN EAST COAST STORM WITH TROPICAL CHARACTERISTICS INITIALLY. MODELS TRACK THIS SYSTEM EAST OF THE LOCAL AREA TO PRECLUDE THE CHANCES FOR PRECIP. MEANWHILE...SFC AND LOWER LEVEL ANTICYCLONIC FLOW SHOULD BRING A NICE MEMORIAL DAY ACROSS ALL OF THE CWA. 850 TEMPS PER ETAXX/AVN/ECMWF/GEM WOULD SUPPORT TEMPS IN THE MID 70S ALTHOUGH SOME DIURNAL CU SHOULD BE AROUND. AS STORM CONTINUES TO MOVE UP THE COAST...NORTHERN BRANCH OF THE JET BECOMES MORE ACTIVE WITH A FEW WAVES NOTED FOR MID WEEK. QPF FROM ETAXX/AVN/GEM PICK UP ON THIS WAVE TO BRING A CHANCE FOR SHOWERS/THUNDERSTORMS. THE KEY HERE IS CHANCE...PLENTY DEPENDS ON EVENTUAL TRACK OF EAST COAST SYSTEM AS UPR AIR REGIME MAY HOLD UP A BIT LONGER THAN MODELS ARE SUGGESTING. TEMPS LOOK A BIT MORE REASONABLE AND NEAR CLIMATOLOGY...FINALLY! COORD WITH GRR...THANKS! .DTX...NONE. BGM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO ISSUED BY NATIONAL WEATHER SERVICE SPRINGFIELD MO 430 PM CDT THU MAY 23 2002 430 PM... LARGE COMPLEX OF ELEVATED CONVECTION EDGING INTO SOUTHWESTERN PORTION OF CWA. THIS IS FAIRLY ON TARGET WITH RUC SOLUTION... AND HAVE FOLLOWED IT FAIRLY CLOSELY IN THE NEAR TERM. IN THE MEAN TIME...SURFACE COLD FRONT MOVING SLOWLY SOUTWARD ACROSS NORTHERN PORTIONS OF FORECAST AREA. DO NOT THINK IT WILL MAKE TOO MUCH PROGRESS FURTHER SOUTH...AS IT BECOMES PARALLEL TO MID-LEVEL FLOW. WITH THE FRONT BECOMING QUASI-STATIONARY TONIGHT... AND HIGH PRECIPITABLE WATER IN PLACE...FEEL THREAT OF HEAVY RAINFALL POSSIBLE. LLJ FORECAST TO STRENGTHEN AND VEER OVERNIGHT... AND SHOULD CONTINUE TO FEED HIGH THETAE AIR INTO THE SOUTHWEST FLANK OF COMPLEX. LIFT WILL INCREASE AFTER 06Z...AS SHORTWAVE LIFTS OUT ACROSS KANSAS. WITH RIGHT REAR QUADRANT OF JET POSITIONED OVER SE NEBRASKA/NW MISSOURI...AGEOSTROPHIC FORCING WILL FURTHER ENHANCE LIFT...ENSURING CONTINUATION OF CONVECTION FOR MOST OF THE NIGHT. CONVECTION LIKELY WILL DIMINISH IN COVERAGE TOMORROW...AS SHORTWAVE LIFTS NORTHEAST ACROSS MISSOURI AND FOCUS SHIFTS WEST WITH APPROACH OF STRONGER SHORTWAVE FRIDAY NIGHT. EXPECT SURFACE FRONT TO LIFT NORTHWARD DUE TO THIS NEXT SYSTEM...BUT WITH CONVECTIVE DEBRIS DIDN'T GET TOO CARRIED AWAY WITH TEMPERATURES. BETTER SEVERE THREAT WILL COME TOMORROW AFTERNOON AND EVENING... AS ATMOSPHERE WILL BE SLIGHTLY DRIER AIR IN THE MID-LEVELS AND WIND FIELD WILL STRENGTHEN. COMPLEX OF STORMS EXPECTED TO FORM ALONG FRONT ACROSS SC NEBRASKA AND NC KANSAS...AND ROLL ACROSS CWA FRIDAY EVENING AND NIGHT. CONVECTIVE THREAT WILL DIMINISH ACROSS WESTERN PART OF CWA SHORTLY AFTER MIDNIGHT...BUT WILL LINGER EAST INTO THE PRE-DAWN HOURS. DECIDED TO POST FLOOD WATCH FOR SOUTHERN TIER OF ZONES...AS TRAINING CONVECTION TONIGHT WILL PRODUCE SUFFICIENT RAINFALL TO MEET OR EXCEED FFG TONIGHT. CONTINUED FLOOD WATCH INTO SATURDAY MORNING DUE TO EXPECTED ROUND OF CONVECTION ON FRIDAY. SF 1000 PM... CHANGED WORDING IN THE FAR NW CWA DUE TO PERSISTENT CLOUD COVER AND FRONTAL BOUNDARY ALREADY WORKING INTO THE AREA. HAVE REWORDED CLOUD COVER AND DROPPED TEMPERATURES TO NEARLY STEADY IN THE LOWER 60S. ELSEWHERE CURRENT SATELLITE TRENDS AND LATEST MESOETA DATA INDICATED MORE MOISTURE AT LOWER LEVELS THEN EXPECTED. THEREFORE HAVE CHANGED TO PARTLY SUNNY WORDING AND LOWERED TEMPERATURES A FEW DEGREES MAINLY NORTH OF INTERSTATE 70. NO OTHER CHANGES MADE. CURRENT POPS LOOK GOOD WITH THE MAIN ACTION DEVELOPING THIS AFTERNOON ALONG FRONTAL BOUNDARY AND ANY OUTFLOW BOUNDARIES IN THE SOUTHERN CWA. JLT 400 AM AFD... SATELLITE IMAGERY AND UPPER AIR ANALYSIS SHOW OLD NOAM OMEGA BLOCK CONTINUING TO DE-AMPLIFY...AND EVOLVE INTO WESTERN TROUGH/EASTERN RIDGE LONGWAVE PATTERN...WITH SWLY FLOW ALOFT ACROSS CWA. UPPER LOW NOTED OVER ND ATTM...WITH SECONDARY SHORTWAVE TROUGH/ASSOCIATED VORT MAX DIGGING ALONG CENTRAL SIERRAS. PROFILER DATA INDICATES 70-80KT LLJ AXIS EXTENDING FROM OK NEWD ACROSS E KS. CONVECTION WHICH HAS DEVELOPED ALONG NOSE OF LLJ ACROSS NERN KS/SE NEB INTO NW MO CONTINUES TO PROPAGATE NEWD. ATTM...DON'T PLAN ON HAVING TO INCLUDE MORNING WORDING FOR CONVECTION ACROSS FAR N COUNTIES. OTHERWISE SFC FRONT EXTENDS FROM SERN SD ACROSS SE NEB INTO EAST CENTRAL KS...FROM ROUGHLY A FSD TO OFK TO HLC LINE. SWLY FLOW ALOFT TO CONTINUE ACROSS CWA TODAY AS SIERRA SHORTWAVE DIGS INTO DESERT SW...THUS EXPECT FRONT TO MAKE ONLY VERY SLOW FORWARD PROGRESS TODAY. HAVE SIDED WITH SLOWER 0Z AVN SOLUTION...AND QUICK LOOK AT 06Z META PROGS SEEM TO SUPPORT FRONTAL POSITION LATE THIS AFTERNOON ROUGHLY ALONG I-35 CORRIDOR. SFC DP'S SHOULD CONTINUE TO INC THROUGH THE DAY...REACHING LOW 60S BY LATE THIS AFTERNOON. THIS ALONG WITH DAYTIME HEATING ALLOWING SFC TEMPS TO CLIMB INTO MID TO UPPER 70S...AND H7-5 LAPSE RATES AOA 7.5 C/KM WILL SUPPORT MODERATELY UNSTABLE AIRMASS ALONG/AHEAD OF FRONTAL BOUNDARY THIS AFTERNOON. CWA WILL ALSO BE UNDER RRQ OF DEPARTING H25 JET MAX...ENHANCING VERTICAL MOTION. PROG SOUNDINGS INDICATE CAP WILL ERODE SUFFICIENTLY BY LATE AFTERNOON TO ALLOW FOR CONVECTIVE INITIATION ALONG BOUNDARY. EXPECT SCATTERED THUNDERSTORMS TO DEVELOP AFTER 21Z...WITH ADDITIONAL STORMS FORMING BACK INTO SOUTH CENTRAL KS/NORTHERN OKLAHOMA LATE THIS AFTERNOON/EVENING. INSTABILITY/SHEAR PARAMETERS SUPPORT SLIGHT RISK FOR SEVERE ACROSS AREA. KS/OK STORMS LIKELY TO DEVELOP INTO MCS AS LLJ REDEVELOPS OVERNIGHT...AND TRACK ACROSS SRN/CENTRAL MO. PW VALUES AOA 1.5 INCHES INDICATE LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. FFG VALUES HAVE RECOVERED FROM LAST HEAVY RAIN EVENT ACROSS SOUTHERN ZONES...AS GROUND LOOKS TO BE ABLE TO ABSORB 2-2.5 INCHES BEFORE PROBLEMS MAY ARISE. THUS HAVE HELD OFF ON ISSUING FLOOD WATCH...BUT WILL MENTION HEAVY RAINS POSSIBLE IN ZONES/HWO. OTHERWISE SIERRA SHORTWAVE PROGGED TO EJECT ACROSS PLAINS DURING THE DAY FRIDAY. PRECIP CHANCES WILL DEPEND ON EFFECTS OF THURS CONVECTION ON LOCATION OF FRONT...BUT ETA/AVN MODELS INDICATE FRONT WILL STALL ACROSS CENTRAL MO...THEN LIFT BACK NWD AS WARM FRONT FRI AFTERNOON/EVENING AHEAD OF APPROACHING SHORTWAVE. SFC LOW PROGGED TO DEVELOP ALONG BOUNDARY ACROSS E KS FRI EVENING AND TRACK ACROSS CWA...ENHANCING LOW LEVEL CONVERGENCE. THUS...EXPECT ANOTHER ROUND OF STRONG/SEVERE THUNDERSTORMS LATE FRI AFTERNOON/EVENING. FOR NOW HAVE KEPT POPS IN CHANCE CATEGORY DUE TO UNCERTAINTY WITH POSITION OF SFC BOUNDARIES. MAY SEE LINGERING SHOWERS ACROSS SRN AND ERN ZONES SAT MORNING...SO HAVE KEPT 30 POPS GOING. TEMPERATURE WISE...MADE ONLY SUBTLE CHANGES TO GOING TEMPS THROUGH SAT...BASED ON EXPECTED SFC BOUNDARY LOCATION. REMAINDER OF FORECAST LOOKS TO BE IN GOOD SHAPE...SO HAVE NOT MADE ANY CHANGES ATTM. SEAMAN .EAX... KS...NONE. MO...NONE. mo AREA FORECAST DISCUSSION...UPDATED FOR AVIATION NATIONAL WEATHER SERVICE FORT WORTH TX 1147 AM CDT THU MAY 23 2002 ...AVIATION DISCUSSION... SLOW SURFACE HEATING TODAY HAS PAINSTAKINGLY EATEN AWAY THE LOW CLOUDS THIS MORNING. FINALLY...IT LOOKS LIKE VFR CONDITIONS ARE TAKING OVER...AS THE MORNING SOUNDING SHOWS TEMPS IN THE UPPER 70S WILL MIX OUT THE MOISTURE. TONIGHT...TYPICAL LATE NIGHT LOW CLOUDS SHOULD RETURN FOR MVFR CONDITIONS AFTER 08Z. 30 ...PUBLIC DISCUSSION...1021 AM CDT THU MAY 23 2002 MAIN SHORT TERM FORECAST CONCERNS ARE WINDS AND AFTERNOON SKY COVER. LATEST RUC/ETA SUGGEST THAT THE LOW LEVEL JET WILL WEAKEN THIS AFTERNOON WHICH SHOULD KEEP AREA JUST BELOW WIND ADVISORY CRITERIA. HAVE DECIDED TO MAINTAIN PARTLY CLOUDY WORDING FOR THIS AFTERNOON... ALTHOUGH THIS COULD BE A BIT OPTIMISTIC. STRATOCUMULUS DECK IS FILLING IN BUT LACK OF HIGH CLOUDS ABOVE THE LOWER DECK WILL ALLOW FOR SOME SUNSHINE TO BREAK THROUGH. HAVE ADJUSTED TEMPERATURES DOWN A CATEGORY MOST AREAS WITH A LITTLE MORE CLOUD COVER ANTICIPATED. LOW POPS IN THE NORTHWEST STILL LOOK GOOD GIVEN THE ELEVATED SHOWERS/THUNDERSTORMS CURRENTLY GRAZING THE AREA. .FWD...CAUTION IS ADVISED ON AREA LAKES. 9 tx