AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 820 PM EDT TUE MAY 11 2004 .SHORT TERM...MOST OF THE ACTIVITY IS ON THE WANE AT THIS HOUR...BUT A FEW STRONGER CELLS STILL ONGOING OVER THE SUWANNEE VALLEY. THUNDERSTORM ACTIVITY THIS EVENING HAS BEEN CONCENTRATED ALONG AXIS OF INSTABILITY FROM APALACHEE BAY NORTHEAST TO GLYNN COUNTY. FEEL A GOOD PORTION OF THE REMAINING SHOWERS WILL DISSIPATE LATER THIS EVENING. MODEL CONSENSUS IS LEANING TOWARD A SIMILAR SOLUTION TO LAST NIGHT WHERE SHORTWAVE ENERGY RIDES NORTH ALONG THE WESTERN PERIPHERY OF THE CWA. MESO-ETA AND RUC SHOWING SOME PRECIP GENERATED BY THIS FEATURE INTO THE OVERNIGHT WITH MET POPS IN THE 20 TO 30 PERCENT RANGE. WILL MONITOR RADAR TRENDS OFF THE GULF...BUT AM INCLINED TO LEAVE SLIGHT CHANCE POPS IN FOR THE BALANCE OF THE OVERNIGHT. ALONG THE COAST...COASTAL SHOWERS HAVE BEEN MINIMIZED THIS EVENING AS MID LEVEL DRY AIR BEGINS TO MOVE IN OFF THE ATLANTIC. SHOULD BE ABLE TO GO WITH SILENT 10% POPS FOR COASTAL SECTIONS OVERNIGHT. && .MARINE...OBSERVATIONS HAVE BEEN SPORADIC AT THE BUOYS THIS EVENING...BUT LATEST GLANCE SHOWS OBS MORE IN THE 10 TO 15 KNOT RANGE THAN SUSTAINED 15. WILL UPDATE CURRENT FORECAST TO REFLECT THIS...NO OTHER CHANGES PLANNED. && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. && $$ DEESE/SHASHY fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 100 PM CDT TUE MAY 11 2004 .AVIATION DISCUSSION FOR 18Z TAFS... LEADING EDGE OF WARM FRONT EVIDENCED BY CIGS BELOW 1 KFT AND VSBYS AT OR BELOW 5 MI IS LOCATED ALONG A KCWI-KRFD-KUGN LINE AT 18Z. FRONT WILL CONTINUE TO MAKE NORTHWARD PROGRESS THIS AFTERNOON AND MOVE INTO SRN WI BY 21Z. ALTHOUGH ATMOSPHERE SOUTH OF FRONT IS UNCAPPED AND LATE AFTERNOON CAPES WILL BE APPROACHING 1500 J/KG... BEST AREAS FOR TSRA DEVELOPMENT THROUGH 21Z WILL BE CENTRAL IL/IN...AND RIGHT ALONG WARM FRONT. SCT TSRA WILL DEVELOP IN OTHER AREAS AFT 21Z. SINCE NOT A CLEAR SIGNAL OF ADDITIONAL DEVELOPMENT AREAS AND HIT AND MISS NATURE...WILL OPT TO LEAVE TSRA OUT OF AREA TAFS AT THIS TIME. SFC WINDS WILL LIKELY REMAIN IN 15-20 KT RANGE THROUGH 18Z WED...AND WILL HIGH MOISTURE CONTENT...EXPECT MVFR VSBYS 09-14Z TIME FRAME. STEFKOVICH && .DISCUSSION... UPDATED THE ZONES TO EXPAND SHRA/TSRA WORDING FOR THE ENTIRE FIRST PERIOD. LAST FEW RUNS OF THE RUC AND PAST TWO META IN CONJUNCTION WITH 88D TRENDS ALL POINT TO THE ACTIVITY JUST SOUTH OF THE CWA TO WAN AND WAX THROUGH THE DAY ASSOCIATED WITH FRONTAL LIFTING AND NORTHWARD PROPAGATING VORT MAX. THINK BEST OPPORTUNITY FOR SFC BASED CONVECTION WILL BE WITHIN THE WARM SECTOR LATER TODAY. AEP .PREVIOUS DISCUSSION BELOW... FOR THIS MORNING, AREAS OF FOG ARE EXPECTED TO DISSIPATE BY 15Z ONCE SOUTHERLY FLOW BECOMES ESTABLISHED MIXING OUT THE LOW-LVL MOISTURE. FOR TODAY/TONIGHT THE COLD FRONT THAT MOVED SOUTH ACROSS NRN IL YESTERDAY WILL MIX BACK NORTH TODAY AS A WARM FRONT. CURRENT WEAKLY ORGANIZED CONVECTION ALONG/NORTH OF THE FRONT IN ERN MO/IL/IN WILL SERVE TO SLOW THE NORTHWARD MOTION THIS MORNING. HOWEVER, AS A STOUT CNTRL ROCKIES CYCLONE EJECTS ON TO THE CNRTL PLAINS THE AGEOSTROPHIC BNDRY LAYER RESPONSE ACROSS THE UPR MIDWEST WILL ALLOW FOR RAPID MIXING OF THE FRONT COME EARLY AFTERNOON...WITH THE FRONT NORTH OF THE CWA BY TONIGHT. THIS PLACES OUR REGION BACK WITHIN THE WARM SECTOR POSING SEVERAL ISSUES. THE FIRST IS TODAY'S HIGH TEMPS. HAVE GONE AHEAD AND RAISED HIGHS TO THAT OF THE PAST SEVERAL DAYS GIVEN THE RETURN OF THE SAME WARM, MOIST AIRMASS AND LACK OF DENSE CLOUD COVER. SECOND ISSUE REVOLVES AROUND PRECIP CHANCES. MODERATE INSTABILITY (100 MB MLCAPE <1300 J/KG) DEVELOPS THIS AFTERNOON WITH WEAK INHIBITION SETTING THE STAGE FOR POSSIBLE TSRA DEVELOPMENT. PROGGED 0-3 AND 0-6 KM SHEAR PROFILES IN CONJUNCTION WITH ADDITIONAL THERMODYNAMIC AND KINEMATIC PARAMETERS (E.G., LCL-LFC RHS, 0-3 KM EHI, DCAPE) INDICATE A FEW STORMS MAY BE BRIEFLY ORGANIZED BUT THE PROBABILITY FOR SVR APPEARS LOW. DUE TO A LACK OF AN INITIATION FOCAL MECHANISM WITHIN THE ANTICIPATED WARM SECTOR, I BROAD BRUSHED POPS ACROSS THE ENTIRE CWA. WHAT ACTIVITY THERE MAY BE THIS AFTERNOON IS ANTICIPATED TO CEASE THIS EVENING WITH THE LOSS OF THE INSTABILITY (DAYTIME HEATING). ON WED MILD HIGH TEMPS SHOULD CONTINUE ALONG WITH PRECIP CHANCES WED AFTERNOON AND NIGHT. A MID-LVL S/WV TROUGH IS PROGGED TO COME AROUND ITS PARENT NRN PLAINS LONG-WAVE TROUGH AND TRANSLATE NORTHWARD ACROSS MN/WRN WI. OMEGA FIELDS OVER THE CWA IMPROVE ACCORDINGLY WITH BOTH THE GFS AND ETA GENERATING QPF. AS THE S/WV TROUGH PASSES INTO CANADA, A SFC COLD FRONT ENCROACHES FROM THE NORTHWEST EARLY THR. BOTH THE ETA AND GFS HANG THE FRONT UP ACROSS THE CWA THR INTO FRI...ATHOUGH THE TWO MODELS DIFFER ON TIMING AND PLACEMENT. THIS MAKES HIGH TEMP FCST'G A BIT CHALLENGING THESE TWO DAYS. AS THE PARENT LONG-WAVE TROUGH AXIS BROADENS ACROSS THE UPPER CONUS, A SERIES OF S/WV TROUGHS WILL TRANSLATE OVER/CLOSE TO NRN IL. ALTHOUGH TIMING OF THESE FEATURES IS DIFFICULT THIS FAR OUT IN TIME, THE DISTURBANCES COMBINED WITH A THEN QUASI-STATIONARY FRONT DRAPPED ACROSS THE REGION WILL SERVE AS A CATALYST FOR REPEATED BOUTS OF TSRA/MCS DEVELOPMENT THR AFTERNOON INTO FRI MORNING. THE FRONT SHOULD REGAIN FWD (SOUTHERLY) MOTION WITH A RESURGENCE OF COOLER AIR FROM THE NORTH, POSITIONING WELL SOUTH OF THE REGION BY FRI NIGHT. WITH THE FRONT OUT OF THE PICTURE AND A LACK OF UPR-LVL S/WV POTENTIAL ENERGY, AS OF NOW THE WEEKEND APPEARS, DARE I SAY, DRY AND MILD. AEP && .LOT...WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LK MI...NONE. $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 632 AM CDT TUE MAY 11 2004 .DISCUSSION... UPDATED THE ZONES TO EXPAND SHRA/TSRA WORDING FOR THE ENTIRE FIRST PERIOD. LAST FEW RUNS OF THE RUC AND PAST TWO META IN CONJUNCTION WITH 88D TRENDS ALL POINT TO THE ACTIVITY JUST SOUTH OF THE CWA TO WAN AND WAX THROUGH THE DAY ASSOCIATED WITH FRONTAL LIFTING AND NORTHWARD PROPAGATING VORT MAX. THINK BEST OPPORTUNITY FOR SFC BASED CONVECTION WILL BE WITHIN THE WARM SECTOR LATER TODAY. AEP .PREVIOUS DISCUSSION BELOW... FOR THIS MORNING, AREAS OF FOG ARE EXPECTED TO DISSIPATE BY 15Z ONCE SOUTHERLY FLOW BECOMES ESTABLISHED MIXING OUT THE LOW-LVL MOISTURE. FOR TODAY/TONIGHT THE COLD FRONT THAT MOVED SOUTH ACROSS NRN IL YESTERDAY WILL MIX BACK NORTH TODAY AS A WARM FRONT. CURRENT WEAKLY ORGANIZED CONVECTION ALONG/NORTH OF THE FRONT IN ERN MO/IL/IN WILL SERVE TO SLOW THE NORTHWARD MOTION THIS MORNING. HOWEVER, AS A STOUT CNTRL ROCKIES CYCLONE EJECTS ON TO THE CNRTL PLAINS THE AGEOSTROPHIC BNDRY LAYER RESPONSE ACROSS THE UPR MIDWEST WILL ALLOW FOR RAPID MIXING OF THE FRONT COME EARLY AFTERNOON...WITH THE FRONT NORTH OF THE CWA BY TONIGHT. THIS PLACES OUR REGION BACK WITHIN THE WARM SECTOR POSING SEVERAL ISSUES. THE FIRST IS TODAY'S HIGH TEMPS. HAVE GONE AHEAD AND RAISED HIGHS TO THAT OF THE PAST SEVERAL DAYS GIVEN THE RETURN OF THE SAME WARM, MOIST AIRMASS AND LACK OF DENSE CLOUD COVER. SECOND ISSUE REVOLVES AROUND PRECIP CHANCES. MODERATE INSTABILITY (100 MB MLCAPE <1300 J/KG) DEVELOPS THIS AFTERNOON WITH WEAK INHIBITION SETTING THE STAGE FOR POSSIBLE TSRA DEVELOPMENT. PROGGED 0-3 AND 0-6 KM SHEAR PROFILES IN CONJUNCTION WITH ADDITIONAL THERMODYNAMIC AND KINEMATIC PARAMETERS (E.G., LCL-LFC RHS, 0-3 KM EHI, DCAPE) INDICATE A FEW STORMS MAY BE BRIEFLY ORGANIZED BUT THE PROBABILITY FOR SVR APPEARS LOW. DUE TO A LACK OF AN INITIATION FOCAL MECHANISM WITHIN THE ANTICIPATED WARM SECTOR, I BROAD BRUSHED POPS ACROSS THE ENTIRE CWA. WHAT ACTIVITY THERE MAY BE THIS AFTERNOON IS ANTICIPATED TO CEASE THIS EVENING WITH THE LOSS OF THE INSTABILITY (DAYTIME HEATING). ON WED MILD HIGH TEMPS SHOULD CONTINUE ALONG WITH PRECIP CHANCES WED AFTERNOON AND NIGHT. A MID-LVL S/WV TROUGH IS PROGGED TO COME AROUND ITS PARENT NRN PLAINS LONG-WAVE TROUGH AND TRANSLATE NORTHWARD ACROSS MN/WRN WI. OMEGA FIELDS OVER THE CWA IMPROVE ACCORDINGLY WITH BOTH THE GFS AND ETA GENERATING QPF. AS THE S/WV TROUGH PASSES INTO CANADA, A SFC COLD FRONT ENCROACHES FROM THE NORTHWEST EARLY THR. BOTH THE ETA AND GFS HANG THE FRONT UP ACROSS THE CWA THR INTO FRI...ATHOUGH THE TWO MODELS DIFFER ON TIMING AND PLACEMENT. THIS MAKES HIGH TEMP FCST'G A BIT CHALLENGING THESE TWO DAYS. AS THE PARENT LONG-WAVE TROUGH AXIS BROADENS ACROSS THE UPPER CONUS, A SERIES OF S/WV TROUGHS WILL TRANSLATE OVER/CLOSE TO NRN IL. ALTHOUGH TIMING OF THESE FEATURES IS DIFFICULT THIS FAR OUT IN TIME, THE DISTURBANCES COMBINED WITH A THEN QUASI-STATIONARY FRONT DRAPPED ACROSS THE REGION WILL SERVE AS A CATALYST FOR REPEATED BOUTS OF TSRA/MCS DEVELOPMENT THR AFTERNOON INTO FRI MORNING. THE FRONT SHOULD REGAIN FWD (SOUTHERLY) MOTION WITH A RESURGENCE OF COOLER AIR FROM THE NORTH, POSITIONING WELL SOUTH OF THE REGION BY FRI NIGHT. WITH THE FRONT OUT OF THE PICTURE AND A LACK OF UPR-LVL S/WV POTENTIAL ENERGY, AS OF NOW THE WEEKEND APPEARS, DARE I SAY, DRY AND MILD. AEP && .AVIATION DISCUSSION FOR 12Z TAFS... OLD FRONTAL BOUNDARY HAS MOVED SOMEWHERE BETWEEN JOLIET AND KANKAKEE OVER TO PERU AND MOLINE. LOW ST AND FOG APPEARS TO BE INCREASING THIS MORNING NORTH OF THIS BOUNDARY...WHICH SHUD BE GAINING MOMENTUM NORTHWARD BFR AFTN. THIS BOUNDARY CLEARING RFD- ORD BY 22Z. WINDS SHOULD PICK UP TO 10 KTS OR SO AND VEER TO EAST AS LOW IN WYOMING DEEPENS AND SHIFTS EAST INTO SD THIS MRNG. THIS WILL INCREASE GRADIENT OVER MS VLY AND PROVIDE A STRONGER NORTHWARD PUSH OF THIS BOUNDARY FOR THIS AFTN. WITH EAST WINDS...COOLER LAKE TEMPS WILL HELP KEEP ST AND FOG IN PLACE ALTHO STRONGER WINDS SHUD ALLOW SOME MIXING AND THUS SOME IMPROVEMENT WITHIN THE INVERSION LAYER. WILL PICK UP CIGS AND VSBY BY 15Z AND THEN SHIFT WINDS MORE SOUTHEAST IN ANTICIPATION OF FROPA THIS AFTN. SHOWERS AND TSTMS SOUTH OF THIS FRONT APPEAR TO BE FADING AS THEY PROGRESS NORTH. HEATING AND INCREASED AFTN FORCING SHUD PROVIDE IMPETUS FOR BETTER ADVANCEMENT INTO TERMINALS THIS AFTN. WILL HOWEVER LEAVE TERMINALS DRY FOR NOW SINCE TIMING IS A TEDIOUS ISSUE. MAIN CONCERN NOW IS GETTING RID OF ST AND FOG. AFTER FROPA...WINDS SHIFT TO SOUTH...WARM SFC AIR DESTROYS INVERSION...AND THUS FOG AND ST SHUD NOT BE AN ISSUE TONIGHT. WILL IN FACT GO FOR BKN TO SCT MID LVL CIGS TONIGHT WITH A STEADY SOUTH WIND AROUND 10 KTS. RLB && .LOT...WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LK MI...NONE. $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1150 AM CDT TUE MAY 11 2004 .DISCUSSION... PRIMARY FCST CONCERNS FOR MRNG UPDATE WERE WNDS AND PCPN CHCS TDA. CONVECTION PREVIOUSLY OFF TO OUR W AND SE HAS DSIPTD BY MIDDAY. 16Z SFC ANLYS SHOWS WRMFNT ACRS EXTRM NRN MO INTO NRN IL WITH DIFFERENTIAL HEATING BNDRY THRU CNTRL PTNS OF STATE ON WRN EDGE OF MRNG DENSE FOG. 12Z ETA/RUC BOTH SHOW CIN NRLY GONE BY AFTN WITH ETA MORE UNSTABLE. CNVGNC WEAK BUT RUC DOES INCR IT A BIT OVR CNTRL IA BY EARLY AFTN AND CU IS ALREADY STARTING TO DVLP ON WHAT LOOKS TO BE DIFFERENTIAL HEATING BNDRY...SO HAVE ADDED LOW AFTN POPS FA WIDE. ANOTHER CONCERN WAS WNDS WITH STG MSLP GRADIENT THRU MO RVR VLY. RUC/ETA SOUNDINGS SUGGEST WE COULD MIX DOWN WND GUSTS AOA 40KTS NWRN SXNS SO ISSUED WND ADVY FOR THESE LOCATIONS BLENDING INTO KOAX/KFSD/KMPX ADVYS. HIGHS TDA SEEM FINE SO DID NOT MAKE ANY OTHER CHGS BYD FITTING TO CURRENT WX. && .DMX WATCHES/WARNINGS/ADVISORIES...WND ADVY 17Z-24Z PTNS OF NWRN AND N CNTRL IA. && $$ SMALL ia AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE GOODLAND KS 829 PM MDT TUE MAY 11 2004 .DISCUSSION...HAVE DECIDED TO LET THE WIND HIGHLIGHTS EXPIRE. A FEW LOCATIONS IN THE NORTHERN AND WESTERN SECTIONS ARE HUGGING THE WIND ADVISORY CRITERIA RIGHT NOW. RUC IS CATCHING THE CURRENT SCENARIO WELL...AND SAYS WE SHOULD BE BELOW WIND ADVISORY CRITERIA BY 03Z. A ISOLATED SPOT MAY GET THERE...BUT DO NOT SEE A PROLONGED TIME PERIOD OF 30 MPH OR HIGHER WINDS AS FRONTAL TROUGH IS NOT THAT FAR AWAY AND IS GETTING CLOSER. HOWEVER...ONE THING THAT BOTHERS ME A LITTLE BIT ARE THE STRONG 850 MB WINDS THAT ARE STILL IN PLACE AND FORECAST TO BE IN PLACE THROUGH THE NIGHT. HOWEVER...THE FULL FORCE OF THOSE WINDS IS NOT GETTING MIXED DOWN AT THIS TIME. SAYING THAT...LOOKS LIKE RIGHT BEHIND THE FRONT THE NORTH WINDS WILL BRIEFLY GET CLOSE TO ADVISORY CRITERIA AS WELL. HOWEVER...THE SPEEDS ARE MARGINAL AND THE TIME PERIOD DOES NOT LOOK THAT LONG. RUC IS HANDLING COLD FRONT ARRIVAL TIMING NICELY...AND WILL USE FOR THE UPDATE. WILL DEFINITELY STAY IN THE BREEZY TO WINDY CATEGORY THROUGH THE NIGHT. NOT REAL BIG ON ANY THUNDERSTORMS DUE TO DRIER AIR MASS ABOVE THE LOW LEVELS. HOWEVER...WITH THE LIFT MOVING IN...KEEPING A A 30 PERCENT CHANCE OUT IS REASONABLE. WILL TAKE A QUICK LOOK AT THE MINS...AND ADJUST AS NEEDED. BUSY NIGHT...BUT COULD HAVE BEEN A LOT WORSE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ BULLER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 230 PM CDT TUE MAY 11 2004 .DISCUSSION... POPCORN CONVECTION QUICKLY FORMED AREAWIDE THIS AFTERNOON AS SOON AS SUN BEGAN POKING THRU CLOUD COVER. IN ADDITION...A LARGE SEA BREEZE LOOKING COMPLEX PUSHING NORTH INTO THE EAST TX LAKES. WITH THIS IN MIND...WENT CHANCE POPS AREAWIDE TONIGHT...AND LIKELY ACROSS MUCH OF EAST TX...SOUTH OF INTERSTATE 20. WILL INCLUDE WORDING MAINLY BEFORE MIDNIGHT. UPPER LEVEL DIFLUENCE EASES UP AFTER MIDNIGHT ON RUC...SO LEFT OUT HEAVY RAIN WORDING FOR EAST TX. HOWEVER...MAY NEED TO KEEP EYE ON YET ANOTHER CLUSTER OF THUNDERSTORMS WELL FURTHER BACK IN SE TX. DEEP MOISTURE WILL REMAIN ACROSS MAINLY LA SECTIONS WEDNESDAY...GUIDANCE NOT TAPERING OFF POPS UNTIL LATER IN THE DAY SO LEFT IN DAYTIME CONVECTION. HOWEVER...TOOK OUT POPS WED EVENING THRU THU MORNING. A COLD FRONT WILL BEGIN MOVING DOWN FROM SOUTHERN PLAINS THURSDAY AFTERNOON...SO WARM AIRMASS INSTABILITY WILL BE QUESTION MARK FOR AFTERNOON CONVECTION. PUT IN LOW POPS... AND INCREASE FROM THE RED RIVER VALLEY STARTING THURSDAY EVENING. SLOW MOVEMENT OF FRONT COULD RESULT IN HEAVY RAIN EPISODE IF FRONT STALLS OUT...ALTHOUGH IT MAY REACH THE INTERSTATE 20 CORRIDOR...AND THEN BACK TO THE NORTH AS IT DISSIPATES. ALTHOUGH STILL IN THE EXTENDED PORTION OF FORECAST...LATER SHIFTS MAY NEED TO PREPARE FOR LIKELY POPS...HEAVY RAIN...AND POSSIBLY SEVERE FOR MUCH OF THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... SHV 68 84 70 83 / 40 30 0 20 MLU 65 81 69 82 / 40 40 0 20 TXK 66 83 70 82 / 40 30 0 30 TYR 69 84 70 82 / 60 20 0 30 LFK 69 85 71 83 / 60 30 0 20 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 07 la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 405 PM EDT TUE MAY 11 2004 .SHORT TERM... UPPER PATTERN WHICH HAS BEEN MAINLY ZONAL OF LATE WILL BECOME A BIT MORE AMPLIFIED WITH TIME THROUGH THE REMAINDER OF THE WEEK. CURRENT UPPER PATTERN FEATURES A TROUGH ACROSS THE ROCKIES...WITH RIDGING ACROSS THE SOUTHEAST U.S. THE UPPER TROUGH WILL GRADUALLY PUSH THROUGH THE PLAINS AND APPROACH THE WESTERN GREAT LAKES TOWARD WEEKS END. AT THE SURFACE...A LOW IN THE HIGH PLAINS WILL GRADUALLY MOVE EAST TONIGHT...WHICH WILL SHIFT THE WARM FRONT NORTHWARD ACROSS LOWER MICHIGAN. THE FORECAST AREA WILL THEN BE IN THE WARM SECTOR FOR WEDNESDAY AND WEDNESDAY NIGHT. THURSDAY INTO FRIDAY...THE FRONTAL BOUNDARY ASSOCIATED WITH THE UPPER TROUGH WILL GRADUALLY PRESS INTO THE AREA FROM THE WEST. FORECAST CONCERNS WILL BE CHANCE FOR STRONG STORMS THIS EVENING ALONG THE WARM FRONT...THEN ASCERTAINING CHANCES FOR THUNDERSTORMS FOR THE REMAINDER OF THE WEEK. WILL OPT TO FOLLOW THE GFS THIS GO AROUND. LIKE ITS SLOWER PROGRESSION TO THE FRONT...AND ITS WEAKER INITIAL LOW MOVING THROUGH THE NORTHERN PLAINS WEDNESDAY NIGHT. FOR TONIGHT...EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP OVER AND ADVECT INTO SOUTHERN LOWER MICHIGAN LATE THIS AFTERNOON AND EVENING. A WEAK LOW LEVEL JET DEPICTED IN THE RUC AND THE ETA WILL LIKELY AID DEVELOPMENT AS IT INTERSECTS THE WARM FRONT ALOFT. LI/S HAVE FALLEN INTO THE -4 TO -6 RANGE OVER NORTHERN INDIANA. THE INSTABILITY COMBINED WITH THE WARM FRONT SHOULD LEAD TO SCATTERED SHOWER AND THUNDERSTORMS. STORMS HAVE ALREADY DEVELOPED IN THE WARM SECTOR. FEEL SOME STORMS THIS EVENING COULD BE ON THE STRONG SIDE WITH MARGINAL WIND AND HAIL BEING THE MAIN STORM THREATS...AS WELL AS HEAVY RAIN. WILL USE SCATTERED SHOWER AND THUNDERSTORM WORDING. WEDNESDAY...WILL CARRY A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE AFTERNOON AS THERE WILL BE ENOUGH INSTABILITY IN PLACE. LAKE BREEZE MAY KICK OFF SOME SCATTERED ACTIVITY. SHOULD BE A WARM DAY WITH HIGHS INTO THE 80S INLAND. WEDNESDAY NIGHT...WILL CARRY CHANCE POPS IN THE EVENING...WITH LIKELY POPS IN THE WEST OVERNIGHT. THE MAIN FRONTAL BOUNDARY WILL BE MOVING THROUGH WISCONSIN LATE. THE BOUNDARY REMAINS JUST WEST OF THE AREA THURSDAY AND THURSDAY NIGHT AND WILL MAINTAIN THE GOING CHANCE POPS. ON FRIDAY...WILL CARRY LIKELY POPS AS THE MAIN SHORTWAVE MOVES INTO THE WESTERN GREAT LAKES AND THE FRONTAL BOUNDARY MOVES INTO THE FORECAST AREA. .LONG TERM... THE FRONT WILL MOVE EAST OF THE CWA BY SATURDAY WITH HIGH PRESSURE QUICKLY FOLLOWING. THIS WILL GIVE THE AREA A WELL DESERVED DRY SPELL INTO EARLY NEXT WEEK. WILL CARRY CHC POPS INTO SATURDAY MORNING ACROSS THE SE WHERE A FEW SHOWERS OR STORMS MAY LINGER. A FEW SHOWERS MAY BE POSSIBLE IN THE NORTH LATE SUNDAY NIGHT/EARLY MONDAY AS A WARM FRONT LIFTS THROUGH THE AREA WITH DECENT WARM AIR ADVECTION. WILL CONTINUE CHC POPS IN THE NORTH INTO MONDAY NIGHT AS A COLD FRONT APPROACHES THE REGION. THE FRONT IS PROGGED TO DRIFT OVER THE CWA ON TUESDAY. DAYTIME TEMPS SHOULD HOLD IN THE 60S ON SATURDAY...THEN MAINLY IN THE 70 TO 75 RANGE FOR EARLY NEXT WEEK. JK && .GRR...WATCHES/WARNINGS/ADVISORIES...NONE. && DUKE JK mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 400 PM EDT TUE MAY 11 2004 .DISCUSSION... MAIN FCST CONCERNS ARE SHRA/TSRA POTENTIAL TONIGHT...THEN TIMING OF CONVECTION WED/WED NIGHT AS FRONT ENTERS UPPER MI. WATER VAPOR IMAGERY/RUC ANALYSIS SHOW A DEEP TROF OVER THE ROCKIES...RIDGE OVER SE CONUS AND A VORTEX OVER HUDSON BAY. CONFLUENT FLOW BTWN HUDSON BAY VORTEX AND SE RIDGE HAS RESULTED IN SFC HIGH PRES EXTENDING FROM MANITOBA TO WRN QUEBEC. SFC LOW ASSOCIATED WITH ROCKIES TROF IS LOCATED IN WRN SD. STRONG WAA REGIME DOWNSTREAM OF TROF (AT 850MB 12Z KABR SOUNDING HAD 50KT S WIND AND TEMP 14C WHILE KBIS TEMP WAS +5C) HAS PRODUCED LARGE AREA OF SHRA/TSRA ACROSS ND/NW MN. CLOSER TO HOME...DRY ERY FLOW ON S SIDE OF HIGH PRES RIDGE TO THE N IS DOMINATING FCST AREA ATTM. SFC DWPTS RISE SHARPLY TO THE S...WITH READINGS RISING TOWARD SUMMERLIKE 70F FROM IA TOWARD SRN LWR MI. TONIGHT...850MB WARM FRONT BECOMES MUCH BETTER DEFINED AS IT LIFTS THRU FCST AREA. STRENGTHENING BAROCLINIC ZONE/SHARPENING CONVERGENCE VCNTY OF FRONT TAKES PLACE N/NW OF FCST AREA DURING THE NIGHT... SUGGESTING MAIN PCPN THREAT WILL ALSO BE TO N/NW. AXIS OF LOW-LEVEL JET WILL ALSO REMAIN W OF FCST AREA. NONETHELESS...CONCERNED THAT A FEW SHRA/TSRA COULD DEVELOP AS LOW-LEVEL MOISTURE SURGES BACK INTO THE AREA. ETA FCST SOUNDINGS DO SHOW ELEVATED CAPE OF 500-800J/KG DEVELOPING FOR PARCELS LIFTED FROM AROUND 2KFT. ALTHOUGH AXIS OF LOW-LEVEL JET IS W OF FCST AREA...THERE MAY STILL BE ENOUGH CONVERGENCE TO POP A COUPLE OF SHRA/TSRA AS CIN IS MINIMAL. WILL KEEP MENTION IN THE ISOLD CATEGORY GIVEN UNCERTAINTY. MODELS IN DECENT AGREEMENT IN TIMING COLD FRONT TO NEAR KIWD BY 00Z THU. AIRMASS GETS QUITE UNSTABLE AHEAD OF THE FRONT WED WITH MLCAPE AROUND 1K J/KG WITH BASICALLY NO CIN. DEEP LAYER SHEAR IS ONLY 20-30KT THOUGH...WHICH SHOULD KEEP SVR THREAT ISOLD. HAVE ONLY MADE A FEW ADJUSTMENTS TO GOING FCST AS FAR AS TIMING WITH CONVERGENCE AHEAD OF COLD FRONT BEING THE MAIN TRIGGER FOR CONVECTION. SHOULD FEEL QUITE WARM WED AS DWPTS RISE INTO THE 50S/MAYBE AROUND 60F WITH TEMPS WELL IN THE 70S. SRLY FLOW WILL OBVIOUSLY KEEP ERN COUNTIES COOL WITH FLOW OFF LAKE MICHIGAN...PROBABLY LOW/MID 50S LAKESIDE TO UPPER 60S TOWARD LAKE SUPERIOR. CLOUD COVER AND LESS IDEAL S FLOW INSTEAD OF SW SHOULD KEEP TEMPS FROM REACHING 80S W HALF. WILL CARRY LIKELY POPS ACROSS FCST THU NIGHT WITH FRONT. UNFORTUNATELY...MODEL DIFFERENCES SHOW UP AS ETA BLOWS FRONT E OF THE U.P. BY 12Z THU (DRY THU) WHILE UKMET/GFS HOLD IT UP OVER CNTRL/ERN U.P. DURING THE DAY THU. SLOWER SOLUTION SEEMS TO MAKE SENSE WITH AMPLIFIED PATTERN/STRONG SE RIDGE. CONSENSUS OF SURROUNDING OFFICES AND HPC PREFERENCE ARE TO HOLD FRONT UP LIKE GFS...AND WILL FOLLOW SUIT. SO WILL MAINTAIN SHRA CHC ON THU. ANOTHER WAVE LIFTS NE ALONG FRONT THU NIGHT/FRI AND WILL UP POPS TO LIKELY OVER ABOUT THE E HALF. ENTIRE SYSTEM THEN SLIDES E FRI NIGHT WITH PRONOUNCED DRYING PROGRESSING W TO E. SAT THRU TUE...ECMWF/UKMET/CANADIAN/GFS IN GOOD AGREEMENT AT THE BEGINNING OF THE PERIOD WITH ALL SHOWING HIGH PRES PASSING OVER THE UPPER GREAT LAKES SAT/EARLY SUN. SOME DIFFERENCES SHOW UP WITH NEXT SHORTWAVE EARLY NEXT WEEK. GFS HAS OVERALL FLATTER FLOW THRU UPPER MIDWEST/GREAT LAKES WHEREAS CANADIAN/EC/UKMET ALL HAVE A SOMEWHAT MORE DEFINED PROGRESSIVE SHORTWAVE TROF. RECENT ECMWF RUNS HAVE BEEN MUCH MORE CONSISTENT ON THIS SYSTEM AND SINCE UKMET/CANADIAN RUNS LEND SUPPORT...WILL LEAN TOWARD EC SOLUTION LATE SUN-TUE. WILL MAINTAIN SHRA CHC SUN NIGHT...AND IF ANYTHING MAY NEED TO UP TIMING TO LATE SUN AFTN OVER THE W. WILL HOLD OFF ON THIS FOR NOW. ALTHOUGH EC SHOWS FRONT CLEARING THE AREA EARLY MON...WILL LINGER SHRA CHC THRU MON IN LIGHT OF GFS SOLUTION AND TO ACCOUNT FOR POSSIBLE TIMING CHANGES. HIGH PRES WILL BUILD INTO THE AREA TUE. TEMPS THRU THE PERIOD SHOULD BE FAIRLY CLOSE TO NORMALS. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ROLFSON mi AREA FORECAST DISCUSSION...CORRECTION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1220 PM EDT TUE MAY 11 2004 .UPDATE... WILL DO AN UPDATE TO BACK OFF ON CLOUD COVER. VISIBLE SATELLITE SHOWS CLOUDS SHRINKING AND THINNING AS HIGH PRESSURE TO THE NORTHEAST CONTINUES TO NOSE INTO SOUTHEAST MICHIGAN. WILL LEAVE SMALL CHANCE OF SHOWERS/TSTRMS IN SOUTHERN FOUR COUNTIES AS BEST MOISTURE AND INSTABILITY WILL BE IN THIS AREA ALONG WITH NEARLY STATIONARY WARM FRONT JUST SOUTH OF BORDER. AFTERNOON HIGHS STILL LOOK ON TRACK. && DRC .DISCUSSION... 00Z RAOBS/WATER VAPOR LOOP NORTHERN LOW OVER HUDSON BAY...WITH SHORTWAVE JUST ABOUT THROUGH THE NORTHERN GREAT LAKES. OTHERWISE SHORTWAVE RIDGE UPSTREAM ACROSS THE UPPER MISSISSIPPI/NORTHERN PLAINS...WITH LONGWAVE TROUGH OVER THE WESTERN CONUS. SURFACE ANALYSIS/METARS/RADAR SHOW COLD FRONT JUST ABOUT TO I-94...WITH HIGH PRESSURE BUILDING FROM CENTRAL CANADA ACROSS THE NORTHERN LAKES. REGIONAL RADAR SHOW SOME SHOWERS LINGERING ACROSS THE SOUTHERN CWA SOUTH OF THE FRONT...WITH ADDITION CONVECTION ACROSS NORTHERN INDIANA. WITH A BRIEF PATTERN CHANGE WE GET A RESPITE FROM SEVERE WEATHER FOR A COUPLE DAYS...BUT STILL WITH HAVE PRECIP CONCERNS. FOR TODAY...WEAK UPPER RIDGE BUILDS OVER THE REGION BEHIND DEPARTING SHORTWAVE...AS LONGWAVE TROUGH SHIFTS EAST INTO THE HIGH PLAINS. ETA/GFS BOTH DROP THE FRONT JUST SOUTH OF THE STATE THIS MORNING... THEN TRY TO BRING IT NORTH AGAIN THIS EVENING AS WE DEVELOP A STRONGER SOUTHERLY FLOW. THE 06Z RUC ACTUALLY TAKES THE BOUNDARY FARTHER SOUTH BY 18Z...HOWEVER THINK THIS MAY BE DIFFICULT GIVEN SLOW PROGRESS OVERNIGHT WITH CONVECTION TO THE SOUTH AND WITHOUT MUCH UPPER LEVEL SUPPORT. WILL KEEP CURRENT FORECAST FOR THIS MORNING...SCT SHRA/ISOLD TSRA...GIVEN RADAR/RUC TRENDS AND LIMITED INSTABILITY. FOR THIS AFTERNOON WE COULD SEE ADDITION CONVECTION DEVELOP ALONG/NORTH OF THE FRONT...AND WILL TRANSITION TO CHANCE TSRA WITH SLIGHTLY BETTER INSTABILITY. ETA/GFS HAVE BEEN CONSISTENT LIFTING THE WARM FRONT THROUGH LOWER MICHIGAN THIS EVENING...AS THE SURFACE LOW OVERS INTO THE UPPER MISSISSIPPI VALLEY AND WE SETUP A DEEP SOUTHWESTERLY FLOW OVER THE WESTERN LAKES. HOWEVER GIVEN TRICKINESS REVOLVING RECENT FRONTAL TIMING...WILL CARRY A CHANCE TSRA THROUGH THE NIGHT TO COVER A SLOWER MOVEMENT. WEDNESDAY LOOKS TO BE DIFFICULT AS FAR AS PRECIP CHANCES GO. SOUTHEAST MICHIGAN IS WELL INTO THE WARM SECTION...WITH ETA/GFS BOTH SHOWING GOOD SURFACE-BASED INSTABILITY DURING THE DAY WITH HIGHS IN THE LOWER 80S/DEWPOINTS LOWERS 60S UNDER SUBTLE 500MB COLD POOL. LIS DROP TO -4C AND SB-CAPE INCREASES TO 1500J/KG /MU-CAPE 2500J/KG/. HOWEVER NO DISTINCT BOUNDARIES AROUND WITH FRONT NORTH OF THE CWA BY THIS POINT. SYNOPTICALLY THERE IS NEUTRAL 850-500MB QVECTOR CONVERGENCE...WITH NO UPPER JET SUPPORT UNDER 300MB RIDGE. SOMEWHAT TORN AS TO WHETHER TO KEEP THE DRY FORECAST WITH THIS MUCH INSTABILITY...BUT FIND IT HARD TO JUSTIFY ADDING POPS WITHOUT DYNAMICAL SUPPORT. MAY BE MORE OF A SLIGHT CHANCE POTENTIAL...WHICH IS BELOW CLIMO AND NOT SOMETHING I WOULD ADD AT THIS POINT. UPPER TROUGH CONTINUES TO SHIFT EAST AS IT SLOWLY DEAMPLIFIES. ETA/GFS BOTH SHOW SIGNS OF CONVECTION IN THE 500MB VORTICITY FIELD...AND HARD TO DETERMINE WHICH FEATURES ARE REASONABLE AND WHICH ARE FEEDBACK PROBLEMS. SURFACE LOW LIFTS INTO NORTHERN ONTARIO WEDNESDAY NIGHT...WITH THE COLD FRONT MOVING TOWARD LAKE MICHIGAN BY 12Z THURSDAY. WILL DISCOUNT THE GFS SOLUTION...WHICH DEVELOPS A SURFACE WAVE ALONG THE FRONT IN VICINITY OF PERSISTENT CONVECTIVE SHORTWAVE. WITH FRONT NOT REACHING LOWER MICHIGAN UNTIL THURSDAY... WILL CUT BACK POPS WEDNESDAY NIGHT UNTIL AFTER MIDNIGHT. MAY NOT SEE MUCH UNTIL 12Z. MAIN SHORTWAVE ENERGY EJECTING OUT OF THE UPPER TROUGH TRACKS THROUGH HUDSON BAY ON THURSDAY...TAKING THE SURFACE LOW WITH IT. THIS LEAVES THE TRAILING BAROCLINIC ZONES DRAPED ACROSS THE GREAT LAKES...NEARLY PARALLEL TO THE SOUTHWESTERLY UPPER FLOW. PRECIP CHANCES LOOK PRETTY GOOD AGAIN ON THURSDAY WITH AVAILABLE DIURNAL INSTABILITY...AND THURSDAY NIGHT/FRIDAY WITH BETTER DYNAMICS. HOWEVER UNCERTAIN STILL REMAINS AS TO EXACT TIMING/PLACEMENT OF PRECIP. HARD TO PIN DOWN THE UPPER WAVES EMBEDDED IN THE FAST UPPER FLOW...WHICH WILL LEAD TO WEAK SURFACE WAVES ALONG THE FRONT. GFS/CANADIAN/ETA-XX OFFER DIFFERENT TIMING POSSIBILITIES...AND WILL KEEP MODERATE CHANCE POPS THROUGH THE END OF THE WEEK. && .DTX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ BRAVENDER EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1155 AM EDT TUE MAY 11 2004 .SHORT TERM... FEEL WE ARE GOING TO KEEP QUITE A BIT OF CLOUD COVER AROUND THIS AFTERNOON. THE LOW CLOUDS IN THE SOUTH MAY LIFT A BIT AND DEVELOP SOME HOLES...BUT OVERALL FEEL THE SOUTH IS GOING TO REMAIN MOSTLY CLOUDY...WITH PARTLY CLOUDY SKIES DEVELOPING NORTH. WARM FRONT IS LOCATED ACROSS NORTHERN ILLINOIS AND INDIANA...AND WILL SLOWLY PROGRESS TO THE NORTH THIS AFTERNOON INTO SOUTHERN LOWER MICHIGAN. EXPECT SOME SHOWERS AND THUNDERSTORMS TO DEVELOP TO NEAR AND NORTH OF THE BOUNDARY THIS AFTERNOON AND EVENING. THE 12Z ETA AND THE RUC INDICATE THAT A WEAK LLJ WILL DEVELOP THIS AFTERNOON AROUND 30 KNOTS...INTERSECTING THE WARM FRONT TO OUR SOUTH. GIVEN THE INSTABILITY SOUTH OF THE FRONT...EXPECT SOME ELEVATED THUNDERSTORMS TO DEVELOP. THREAT FOR SEVERE IS SMALL GIVEN FAIRLY WEAK WIND FIELDS AND LOW LEVEL CLOUDINESS. FEEL THE ELEVATED INSTABILITY HOWEVER MAY BE ENOUGH TO TOUCH OFF A FEW STRONG STORMS. WILL BE MONITORING AREA RADARS THIS AFTERNOON FOR DEVELOPMENT. HIGHS IN THE LOWER 70S IN MOST LOCATIONS. && .GRR...WATCHES/WARNINGS/ADVISORIES...NONE. && DUKE mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1043 AM EDT TUE MAY 11 2004 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST UPDATE ARE THE WINDS AND TEMPERATURES FOR THIS AFTERNOON. WATER VAPOR IMAGERY AND RUC/ETA SHOWING A DEEP LOW OVER THE NORTHERN ROCKIES AND A RIDGE OVER THE DAKOTAS EXTENDING INTO SOUTHERN MANITOBA. A SHORTWAVE IS MOVING THROUGH THE RIDGE AND IS OVER THE EASTERN SOUTH DAKOTA. SURFACE ANALYSIS ALSO DEPICTS A DEEP LOW OVER THE BLACK HILLS WITH A WARM FRONT STRETCHING EAST THROUGH SOUTHERN MINNESOTA...THEN SOUTHEAST INTO THE UPPER OHIO RIVER VALLEY. WARM MOIST AIR AHEAD OF THE LOW AND OVERRUNNING THE WARM FRONT AND ACCOMPANYING THE UPPER LEVEL TROUGH OVER SOUTH DAKOTA IS TRIGGERING THUNDERSTORMS IN THE FARGO AREA. A SURFACE RIDGE BLANKETS MUCH OF CENTRAL ONTARIO AND IS KEEPING THE AIR MASS OVER THE FORECAST AREA FAIRLY DRY AND STABLE. THE RIDGE OVER THE DAKOTAS WILL SHIFT A LITTLE EAST THIS AFTERNOON INTO THE UPPER GREAT LAKES REGION AND THE NORTHERN MISSISSIPPI RIVER VALLEY. AS IT DOES IT WILL STEER THE THUNDERSTORMS OVER EASTERN DAKOTAS NORTHEAST INTO WESTERN ONTARIO. THE SURFACE LOW OVER THE BLACK HILLS WILL SHIFT A LITTLE EAST INTO THE SOUTH DAKOTA BADLAND AND BECOME AN ELONGATED TROUGH STRETCHING INTO THE NEBRASKA PANHANDLE. THE ASSOCIATED WARM FRONT WILL MOVE A LITTLE EAST THROUGH THE DAY. THE MID LEVEL DRIER AIR OVER THE FORECAST AREA WILL REMAIN IN PLACE. ETA/GFS SHOWING A STRONG SURFACE BASE INVERSION AND DRY MID LEVEL WILL LIMIT ANY PRODUCTION OF SHOWERS TODAY. THE SOUNDING FORECAST ALSO SUGGEST THE DEVELOPMENT OF CIRRUS...POSSIBLY DUE TO BLOW OFF OF THE THUNDERSTORMS OVER THE DAKOTAS. ETA SOUND INDICATE A LITTLE MOISTENING UP OF THE LOW LEVELS OVER THE WESTERN U.P. IN ASSOCIATION WITH OVERRUNNING OF THE WARM FRONT BY LATE AFTERNOON. THUS LOOKING FOR SOME CU OVER THE WEST. THUS EXPECT HIGH CLOUDS OVER THE AREA TODAY. THIS IS SUPPORTED BY IR/VISIBLE SATELLITE AT THIS TIME. TRAJECTORY FORECAST INDICATES COLD AIR ADVECTION BEHIND THE FRONT THAT MOVED THROUGH THE FORECAST AREA ON MONDAY WILL KEEP THE TEMPERATURES MUCH COOLER TODAY THAN MONDAY. GUIDANCE SO FAR IS LOOKING GOOD. AS THE SURFACE RIDGE SHIFT A LITTLE EAST TODAY...TIGHTER GRADIENTS AHEAD OF THE SURFACE LOW WILL INCREASE WINDS A BIT OVER THE WESTERN U.P. THIS AFTERNOON. THE GOING FORECAST LOOKS GOOD SO DO NOT EXPECT TO MAKE VERY MANY CHANGES ONLY TWEAK THE WORDING. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 930 AM CDT TUE MAY 11 2004 .DISCUSSION... WIND ADVISORY EXPANDED A TIER OF COUNTIES EAST AND ACROSS ALL OF SOUTH CENTRAL MINNESOTA. ADVISORY ALSO EXTENDED UNTIL 8 PM BASED ON NEAR 40 KNOTS MOMENTUM TRANSFER FROM THE RUC MODEL ON BUFKIT. CONVECTION CURRENTLY BRUSHING WEST CENTRAL MINNESOTA APPEARS TO BE ASSOCIATED WITH LOW LEVEL THETA E ADVECTION IN CONCERT WITH UPPER LEVEL DIVERGENCE. THE MODELS INDICATE THIS WILL PASS NORTH OF OUR COUNTY WARNING AREA BY 21Z. EXPECT THE AFTERNOON AND EVENING WILL BE DRY ACROSS MOST OF OUR FORECAST AREA IN THE WARM SECTOR. WARM FRONT NOT WELL DEFINED BUT THINK IT SHOULD PASS THROUGH WITH FORECAST OF SURFACE DEW POINTS AROUND 60...TO MOX AND MSP AROUND 18Z AND SAZ AND JMR AROUND 00Z. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WIND ADVISORY THIS AFTERNOON MNZ041-042-047>049-054>058-064>067-073>077-082>085-091>093- WI...NONE. && $$ mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 235 PM CDT TUE MAY 11 2004 .DISCUSSION... VERY CHALLENGING FORECAST AGAIN TODAY AS SYNOPTIC REGIME MORE TYPICAL OF JULY IS TESTING MY DIAGNOSTIC ABILITIES TO IDENTIFY AND TRACK A NUMBER OF SUBTLE FEATURES. WEAK SOUTHWESTERLY UPPER FLOW PERSISTS AGAIN THIS AFTERNOON AHEAD OF AN UNSEASONABLY STRONG STORM SYSTEM TAKING SHAPE OVER THE NORTHERN ROCKIES. SEVERAL WEAK SOUTHERN STREAM SHORTWAVE TROUGHS WILL INTERACT WITH AN INCREASINGLY MOIST SUBTROPICAL AIRMASS TO DRIVE CONVECTIVE CHANCES IN THE SHORT TERM BEFORE LARGE SCALE SYSTEM APPROACHES ON THURSDAY. SHORT TERM (TONIGHT AND WEDNESDAY)... 18Z SPECIAL SOUNDING CONFIRMS THAT THE LEADING EDGE OF MUCH DEEPER SUBTROPICAL MOISTURE HAS FINALLY CRESTED THE HIGHER TERRAIN TO THE SOUTH AND WAS BEGINNING TO ADVECT INTO THE OZARKS REGION THIS AFTERNOON. DEWPOINTS HAVE RISEN QUITE A BIT SINCE SUNRISE AND ARE NOW IN THE MID 60S IN MANY LOCATIONS. AS EXPECTED YESTERDAY... ISOLATED CONVECTION HAS DEVELOPED WITHIN AN UNCAPPED AND MODESTLY UNSTABLE AIRMASS OVER THE ERN HALF OF THE CWA...LIKELY BEING FORCED BY TERRAIN INDUCED CONVERGENCE AND MESOSCALE OUTFLOW. SHORT LIVED PULSE CELLS WILL GRADUALLY DIMINISH WITH LOSS OF DAYTIME HEATING AND POOR LAPSE RATES AND LACK OF VERTICAL SHEAR PRECLUDE ANY THREAT OF SEVERE WEATHER. FOR TONIGHT...LEAD UPPER SHORTWAVE CENTERED NEAR ABILENE, TX WILL CONTINUE TO ROTATE SLOWLY NORTHEAST TOWARD THE AREA. THIS FEATURE IS HANDLED VERY WELL BY RUC AND ETA MASS FIELDS...WITH A SECOND SOUTHERN STREAM WAVE NOTED OVER NEW MEXICO PER WATER VAPOR IMAGERY. EXPECT TO SEE OUR FIRST ANNUAL BOUT OF GULF STRATUS TONIGHT AS MOIST LOW LEVEL FLOW INCREASES WITHIN MODEST LOW LEVEL JET (WHICH WILL BE NOTABLY STRONGER OVER THE PLAINS AHEAD OF DEEPENING SURFACE LOW). HAVE ALSO PAINTED A LOW CHANCE POP OVER THE FAR SW CORNER AS ELEVATED CONVECTION WILL LIKELY BE ENHANCED JUST DOWNSTREAM OF THIS FEATURE AND MAY REACH THE AREA BEFORE SUNRISE. ON WEDNESDAY...MORNING STRATUS SHOULD BREAK DOWN QUICKLY INTO CUMULUS AND DEEP CONVECTION WITH THE AID OF UPPER LEVEL DISTURBANCES. ANY DAYTIME HEATING SHOULD ALLOW SHOWERS AND STORMS TO DEVELOP FAIRLY EARLY (LATE MORNING) GIVEN UNCAPPED ENVIRONMENT AND UPPER LEVEL SUPPORT...AND EXPECT COVERAGE TO BE MORE WIDESPREAD TODAY WITH INCREASE TO 40 POPS WARRANTED FOR NOW. EXPECT TO SEE SKIES CLEAR FROM WEST TO EAST DURING THE AFTERNOON AS SUBSIDENCE DEVELOPS IN THE WAKE OF THIS LEAD SYSTEM. LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)... THREAT FOR ORGANIZED SEVERE WEATHER WILL KNOCK ON OUR WESTERN DOOR STEP LATE WEDNESDAY NIGHT AS MAIN ROCKIES STORM SYSTEM AND DEEP SURFACE TROUGH APPROACH FROM THE WEST. SEVERE WEATHER EXPECTED TO BE FAIRLY WIDESPREAD AHEAD OF THIS SYSTEM ACROSS THE PLAINS WEDNESDAY EVENING...AND WILL BE A MATTER OF TIMING AND DIURNAL EFFECTS AS TO WHAT REACHES SE KS/WRN MO BY SUNRISE. WILL LIKELY SEE THUNDERSTORMS REINTENSIFY ALONG FRONTAL ZONE DURING THE DAY THURSDAY...HOWEVER THE THREAT FOR SEVERE WEATHER REMAINS QUESTIONABLE. MAIN SURFACE LOW WILL FILL QUICKLY DURING THE DAY AS PRIMARY UPPER LEVEL CYCLONE LIFTS INTO THE CANADIAN PROVINCES. THEREFORE...I AM NOT SOLD ON THE UPPER JET AXIS (AND FAVORABLE DEEP LAYER SHEAR PROFILES) PENETRATING THIS FAR SOUTH. WITH REMNANTS OF MORNING CONVECTION A HINDERING FACTOR...BETTER INSTABILITY AND MOISTURE WOULD SUGGEST THE MAIN SEVERE WEATHER THREAT WOULD BE ACROSS THE SOUTHERN PLAINS CLOSER TO SECONDARY SURFACE LOW AND DRY LINE. WILL CONTINUE TO MONITOR TRENDS AND HOPEFULLY THIS PICTURE WILL BECOME CLEARER BY TOMORROW. CERTAINLY A SLIGHT DEVIATION IN THE STORM TRACK...COMBINED WITH SUFFICIENT DAYTIME DESTABILIZATION COULD LEAD TO A FAIRLY WIDESPREAD EVENT THURSDAY AFTERNOON/EVENING. OTHERWISE...DID NOT DEVIATE FROM PREVIOUS FORECAST WITH GRADUALLY TAPERING PRECIPITATION OFF FROM NORTH TO SOUTH ON FRIDAY...LINGERING RAIN CHANCES ONLY OVER THE FAR SOUTH. WEEKEND AT THIS POINT LOOKS DRY AND SEASONABLE WITH A RETURN TOWARD WARMER AND A MORE HUMID AIRMASS EARLY NEXT WEEK. BOOKBINDER && .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING. SCT-BKN CUMULUS AROUND 5000 FEET WILL BE PREVALENT THROUGH THE LATE AFTERNOON. ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE UNTIL SUNSET RESULTING IN LOCALIZED MVFR CONDITIONS. GUSTY SOUTH WINDS WILL SUBSIDE AFTER MIDNIGHT. CLOUD COVER WILL INCREASE AGAIN LATE TONIGHT INTO WEDNESDAY MORNING WITH AREAS OF MVFR CEILINGS POSSIBLY DEVELOPING. SCATTERED SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS THE REGION WEDNESDAY MORNING IN ADVANCE OF AN APPROACHING UPPER LEVEL DISTURBANCE. FOSTER && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ WFO SGF mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTH PLATTE NE 833 AM CDT TUE MAY 11 2004 .DISCUSSION...WILL GO AHEAD AND ISSUE A WIND ADVISORY FOR THE REMAINDER OF THE FORECAST AREA...WITH THE EXCEPTION OF DEUEL AND GARDEN COUNTIES. WINDS ARE AT OR NEAR ADVZY CRITERIA ALREADY. BOTH THE RUC AND MESO ETA CONTINUE TO INDICATE HIGH WINDS THROUGH EARLY AFTERNOON ACROSS THE WRN TIER OF COUNTIES FROM MERRIMAN TO IML THROUGH 23Z. WILL RUN THE NEW ADVZY THROUGH 23Z. && ...FORECAST FOCUS IN NEAR TERM CONVECTION WITH ADVANCING UPPER TROUGH... .PREVIOUS DISCUSSION... STRONG SURFACE LOW OVER CENTRAL WYOMING WILL CONTINUE TO MOVE OUT ONTO THE NORTHERN PLAINS TODAY. STRONG PRESSURE GRADIENT SETTING UP WILL ISSUE WIND ADVISORY FOR PORTIONS OF SOUTHWEST AND NORTHCENTRAL THIS AFTERNOON. SUBSTANTIAL MOISTURE ADVECTION INTO FORECAST AREA THROUGHOUT TODAY. TD'S IN THE 50S AND 60S THIS AFTERNOON WITH VERY UNSTABLE AIRMASS IN PLACE. WITH SUFFICIENT HEATING THIS AFTERNOON STORMS TO INITIALLY FIRE ALONG DRY LINE AND THEN REALLY GET GOING EARLY THIS EVENING AS COLD FRONT ENTERS NORTHWEST ZONES. CAPES WIND PROFILES ALL SUPPORT LARGE HAIL AND THEN AS THE LINE DEVELOPS IN THE VICINITY COULD BE POSSIBILITY FOR DAMAGING WINDS. BEST CHANCE FOR SEVER INITIALLY ALONG DRY LINE OVER WEST THAN TRANSFERING NORTH ZONES AFTER SUNSET WITH ADVANCING COLD FRONTAL BOUNDARY...REFLECTED IN POPS. HAVE ADJUSTED TEMPS DOWN ON THURSDAY AS BOTH AVN AND ETA SUPPORT COOLER AIR FILTERING IN WITH H5 TROUGH. WEDNESDAY CLOUDY COOLER DAY ACROSS FORECAST AREA. RAIN SNOW MIX STILL ON TRACK FOR NOPRTHWEST ZONES LATE WEDNESDAY NIGHT. REMAINDER OF EXTENDED ONLY MINOR TWEAKS. && .LBF...WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY ALL ZONES EXCEPT DEUEL AND GARDEN COUNTIES THROUGH 23Z. && $$ POWER/CLB ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 830 PM MDT TUE MAY 11 2004 .UPDATE...UPDATED ZONES TO REMOVE THE EXPIRED WIND HIGHLIGHTS AND TRIMMED WINDS FOR REMAINDER OF NIGHT BELOW THE HIGHLIGHT CRITERIA. WINDS STARTING TO DIMINISH...BUT WILL LIKELY STAY WINDY OVERNIGHT ACROSS THE RIDGETOPS ESPECIALLY AND SOME OPEN AREAS AS RUC SHOWS ANOTHER VORT MAX TO ROTATE TO VCNTY FOUR CORNERS BY 12Z WED. WILL HAVE TO WATCH ERN BORDER WITH DEWPOINT AT CVN BACK UP TO 52. WEDNESDAY RED FLAG HIGHLIGHTS STILL CURRENT. .PREV DISCUSSION 253 PM PM MDT TUE MAY 11 2004... NO CHANGES PLANNED TO PREVIOUS HIGH WIND WARNING/WIND ADVISORY AREAS FOR TONIGHT. PROBABLY JUMPED THE GUN ON THE WIND ADVISORY FOR THE UPPER GILA REGION AND SOUTH CENTRAL MOUNTAINS EARLIER...SURPRISE...BUT WILL NOT CANCEL AT THIS POINT. 60-70 KNOT MID-LEVEL WIND MAX PASSING OVER NC/NW NEW MEXICO TONIGHT...SO POTENTIAL EXISTS FOR STRONG OVERNIGHT GUSTS ACROSS THE HIGHER TERRAIN. ALSO WATCHING DEVELOPING CONVECTION ACROSS THE FAR EAST NEAR/AHEAD OF THE DRYLINE BUT PLAN TO KEEP ZERO POPS FROM 00Z ON AS ANY TSRA SHOULD BE EAST OF NEW MEXICO BY 600 PM MDT. OTHERWISE...FAST SOUTHWESTERLY FLOW ALOFT OVER THE AREA TONIGHT THROUGH WEDNESDAY WILL BECOME MORE WEST-NORTHWEST BY THURSDAY AS THE BROAD UPPER TROUGH OVER THE INTERMOUNTAIN REGION TRANSLATES SLOWLY EASTWARD. MAJORITY OF OUR CWA WILL REMAIN ON THE DRY/WINDY SIDE OF THIS SYSTEM...WITH JUST SOME TOKEN SLIGHT CHANCE POPS NEAR THE COLORADO BORDER WEDNESDAY/WEDNESDAY NIGHT AS AN EMBEDDED SHORT-WAVE ROTATES THROUGH BASE OF THE TROUGH AND ACROSS THE FOUR CORNERS REGION. PREVIOUS SHIFT TRIMMED BACK THE COVERAGE OF ISOLD POPS ACROSS THE FAR NORTH DURING THE WEDNESDAY PERIOD WHICH WAS A GOOD CALL - TOO DARN DRY. BAGGY TROUGH HANGING BACK OVER OUR REGION FOR THURSDAY WITH A FEW WEAK WAVES RIPPLING THROUGH. MEANWHILE...A BACKDOOR COLD FRONT EXPECTED TO PUSH INTO FAR NORTHEAST NEW MEXICO PROBABLY THURSDAY MORNING PROVIDING A SHALLOW UPSLOPE ZONE ACROSS THE NORTHEAST THURSDAY AFTERNOON. HOWEVER...THERE ARE STILL SOME SIGNIFICANT TIMING DIFFERENCES AMONG THE MODELS WITH THIS RESPECT TO THIS FEATURE. ETA ALTHOUGH SLOWER THAN ITS PREVIOUS RUNS...STILL SEEMS OVERLY AGGRESSIVE DRIVING THE FRONT SOUTHWARD WEDNESDAY AFTERNOON/EVENING GIVEN DEEP MIXING AND STRONG SOUTHWESTERLY FLOW ALOFT. GFS AT LEAST 12-18 HOURS SLOWER AND AM BEGINNING TO THINK THIS MIGHT BE MORE CORRECT. GFS BRINGS THE FRONT INTO THE NORTHEAST THURSDAY NIGHT. FOR NOW WILL SPLIT THE MIDDLE ON FRONTAL TIMING. INCLUDED A LOW POP ACROSS THE NORTHEAST AND EAST CENTRAL PLAINS THURSDAY/THURSDAY NIGHT. NO BIG CHANGES TO THE LONG RANGE. IF THE SLOWER GFS FRONTAL TIMING COMES TO PASS THEN WE MAY NEED TO INCLUDE POPS ACROSS THE SOUTHEAST FOR FRIDAY DUE TO PROXIMITY OF BOUNDARY....OTHERWISE DRY. LITTLE MORE CONVECTIVELY ACTIVE BY THE WEEKEND AS MOISTURE BEGINS TO INCREASE AND DAYTIME TEMPS WARM. KJ && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON................ 045/074 038/072 037 41010 GALLUP.................... 042/072 033/070 030 41000 GRANTS.................... 045/075 037/073 032 41000 GLENWOOD.................. 046/083 040/080 041 41000 CHAMA..................... 034/066 028/063 026 41010 LOS ALAMOS................ 047/071 038/067 034 41000 RED RIVER................. 039/063 027/060 025 41011 TAOS...................... 042/071 034/069 033 41010 SANTA FE.................. 046/074 038/070 036 41000 SANTA FE AIRPORT.......... 047/077 040/072 038 41000 ESPANOLA.................. 045/079 039/075 039 41000 ALBUQUERQUE HEIGHTS....... 053/080 050/075 049 41000 ALBUQUERQUE VALLEY........ 048/083 044/077 043 41000 ALBUQUERQUE FOOTHILLS..... 050/078 047/073 046 41000 ALBUQUERQUE WEST MESA..... 054/082 048/074 047 41000 SOCORRO................... 054/085 045/081 045 41000 SANDIA PARK/CEDAR CREST... 050/076 042/070 042 41000 MORIARTY/ESTANCIA......... 047/080 040/073 037 41000 CARRIZOZO................. 053/085 047/080 041 41000 RUIDOSO................... 049/078 049/074 039 41000 RATON..................... 042/077 038/070 035 41011 LAS VEGAS................. 044/075 040/069 038 41000 ROY....................... 048/078 045/071 041 41000 CLAYTON................... 051/081 046/069 042 4100- SANTA ROSA................ 054/088 051/081 046 41000 TUCUMCARI................. 056/088 054/079 047 41000 FORT SUMNER............... 055/088 054/083 048 41000 CLOVIS.................... 056/089 056/081 047 41000 PORTALES.................. 056/090 055/081 048 41000 ROSWELL................... 057/092 057/088 052 41000 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING WEDNESDAY AFTERNOON 103-104-106-107-108 BELOW 8000 FEET FIRE WEATHER WATCH WEDNESDAY AFTERNOON NMZ105 BELOW 8000 FEET && $$ 41 nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 940 AM EDT TUE MAY 11 2004 .DISCUSSION... SATELLITE LOCATION OF SHORT WAVE THIS MORNING MORE IN LINE WITH RUC. GFS AND TO A LESSER DEGREE...ETA BRING THIS FEATURE UP THE COAST THROUGH THE AFTERNOON WHILE RUC DRIFTS THIS FEATURE INTO GA/SC. SATELLITE TRENDS INDICATE RUC IS CLOSER TO THE MARK AND GIVEN POSITION OF RIDGE...EXPECT RUC TO VERIFY. THIS SHOULD KEEP MOST OF THE SHOWERS S OF THE AREA. WILL INCLUDE A SMALL POP FOR SC PORTION OF CWA THIS AFTERNOON AND BE MORE PESSIMISTIC WITH THE CLOUD COVER THERE. REMAINDER OF THE FORECAST NEEDS NO ADJUSTMENT. && .MARINE... A LITTLE SHOWER ACTIVITY TO THE S IS NOT EXPECTED TO AFFECT COASTAL WATERS THIS AFTERNOON. WILL MAKE ONLY MINOR TWEAKS TO THE PERSISTENCE FORECAST IN THE UPDATE. && .PRELIMINARY POINT TEMPS/POPS... WILMINGTON 83 62 83 63 / 10 10 10 10 FLORENCE 85 60 85 61 / 30 10 10 10 LUMBERTON 85 60 85 61 / 10 10 10 10 MYRTLE BEACH 79 63 79 64 / 20 10 10 10 && .ILM WATCHES/WARNINGS/ADVISORIES... NC...NONE. SC...NONE. && PUBLIC: DIGIORGI MARINE: TM nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 745 PM CDT TUE MAY 11 2004 THREE MAIN AREAS OF CONVECTION EARLY THIS EVENING. AREA AFFECTING SOUTHERN AND CENTRAL OKLAHOMA ASSOCIATED WITH HEATING AND UPPER WAVE WHICH IS FORECAST TO LIFT INTO WESTERN MISSOURI AND ARKANSAS BY EARLY WEDNESDAY. SO EXPECT THIS AREA OF RAIN TO MOVE EAST OF FA BY LATE THIS EVENING. OTHER TWO AREAS OF CONVECTION HAVE FORMED ACROSS TEXAS PANHANDLE. GFS SUGGEST UPPER JET TO MOVE INTO FAR WEST TEXAS BY EARLY WEDNESDAY WITH 40 TO 50 KT LLJ AXIS SITUATED ACROSS WESTERN PARTS OF FA. CONVECTION WILL WEAKEN SOME WITH LOSS OF HEATING BUT SHOULD CONTINUE INTO WESTERN THIRD OR HALF OF FA LATE TONIGHT INTO THE OVERNIGHT HOURS. WILL INCREASE POPS SOME ACROSS WESTERN PARTS FOR LONGER PERIOD THAN INDICATED IN CURRENT GRIDS. SIX __________________________ 332 PM CDT TUE MAY 11 2004 .DISCUSSION... SHORTWAVE TROUGH NEAR ABILENE...BEST MONITORED WITH 600 MB RUC... WILL ADVANCE SLOWLY NORTHEASTWARD...REACHING SOUTHEAST OKLAHOMA BY 06Z. DIFFERENTIAL HEATING AND A WEAK CAPPING INVERSION HAVE ALREADY BEEN SUFFICIENT FOR ABOUT 30 PERCENT AREAL COVERAGE NEAR AND NORTH ITS TRACK. WILL INCLUDE 30 TO 50 POPS THIS EVENING ALONG AND EAST OF INTERSTATE 44...WITH ACTIVITY EXPECTED TO DIMINISH SHORTLY AFTER SUNSET. AS THE TROUGH EXITS THE REGION AFTER MIDNIGHT...850 TO 700 MB FLOW IS EXPECTED TO VEER IN ITS WAKE...WHICH MAY SUPPORT ANOTHER SLIGHT CHANCE OF HIGH BASED -SHRA/TS LATER IN THE NIGHT AS THE LOW LEVEL JET DEVELOPS...AFFECTING AREAS MAINLY ALONG AND EAST OF INTERSTATE 35. DEVELOPING DRYLINE FROM EASTERN COLORADO INTO EASTERN NEW MEXICO IS EXPECTED TO BE ANOTHER AREA TO MONITOR FOR CONVECTIVE INITIATION OVER THE NEXT FEW HOURS...BEFORE DIMINISHED HEATING ALLOWS THE CAPPING INVERSION TO REINTENSIFY. AVERAGE STORM MOTIONS ACROSS THIS REGION WILL CONTAIN A SLIGHTLY MORE EASTWARD COMPONENT AND THUS STAND A SLIGHTLY BETTER CHANCE OF MAKING IT INTO WESTERN PARTS OF THE FORECAST AREA BEFORE ENDING TOWARD MIDNIGHT. FOR WEDNESDAY...CONCERN SHIFTS NORTHWESTWARD WHERE RUC/ETA MODEL INITIALIZATIONS ARE IN CLOSEST AGREEMENT WITH 12Z UPPER AIR OBSERVATIONS...WHEREAS THE GFS QUICKLY AMPLIFIES...PERHAPS OVERAMPLIFIES...SHORTWAVE TROUGH DEVELOPING THIS MORNING OVER WASHINGTON/OREGON. ALTHOUGH VERY FAR AWAY...EVOLUTION IN THIS AREA MAY PLAY A PIVOTAL ROLE WITH REGARDS TO FRONT AND SURFACE LOW POSITIONS BY LATE WEDNESDAY. HAVE RELIED HEAVILY ON RUC THROUGH THE NEXT 12 HRS...THEN FOLLOWED THE ETA THEREAFTER...WHICH SHOWS AN INITIAL SURGE OF THE COOLER AIR OVER THE NORTHERN PLAINS ENTERING NORTHWEST OKLAHOMA EARLY WEDNESDAY...WITH THE SURFACE LOW REORGANIZING WEST OR SOUTHWESTWARD FROM THE CENTRAL PLAINS LATE IN THE DAY. DURING THIS PERIOD...EXPECT EARLY MORNING -TSRA OVER THE EASTERN ONE THIRD OF THE AREA TO END...AS A STRONG CAPPING INVERSION BUILDS IN ADVANCE OF THE APPROACHING LONG WAVE TROUGH. CONVECTIVE INITIATION IS EXPECTED TO OCCUR LATE WEDNESDAY ALONG THE EVOLVING FRONTAL BOUNDARY OVER KANSAS...WITH ADDITIONAL DEVELOPMENT OCCURRING FARTHER WESTWARD NEAR REORGANIZING SURFACE LOW...WHERE MOIST UPSLOPE FLOW WILL BE INCREASING. EXPECT A LARGE SLOW MOVING MCS TO DEVELOP OVER SOUTHEAST COLORADO...SOUTHWEST KANSAS...AND THE OKLAHOMA PANHANDLE...WITH EVOLUTION OCCURRING EAST SOUTHEASTWARD ALONG AND JUST SOUTH OF THE KANSAS/OKLAHOMA STATE WEDNESDAY NIGHT. THIS SCENARIO CONSIDERS THAT THE COLD FRONT MAY BE FARTHER SOUTH OR MOVING SOUTH FASTER THAN DEPICTED BY THE MODELS...AND THAT THE ETA CONVECTIVE PARAMETERIZATION DOES NOT FACTOR EVAPORATIVE COOLING AND/OR CONVECTIVE OUTFLOW IN REDIRECTION OF AN MCS. MCS WILL LIKELY BE IN PROGRESS OVER PARTS OF THE FORECAST AREA THURSDAY MORNING...WITH THURSDAY'S FORECAST DOMINATED BY THE MESOSCALE. HAVE CONTINUED WITH HIGH POPS NEAR AND SOUTHEAST OF THE EXPECTED MCS POSITION THURSDAY MORNING WITH CONVECTION LIKELY ONGOING ALL DAY. OUTFLOW BOUNDARY MAY PUSH EFFECTIVE BOUNDARY SOUTHWARD INTO TEXAS...WITH POTENTIAL FOR SEVERE CONFINED TO NEAR THE RED RIVER AND AREAS SOUTH. OTHERWISE EXPECT COOL AND NEARLY SATURATED LOWER LEVEL AIR TO BE FLOWING UPSLOPE OVER NORTHWEST OKLAHOMA AND PORTIONS OF THE OKLAHOMA/TEXAS PANHANDLES...WITH HIGH TEMPS THURSDAY POSSIBLY NOT GETTING OUT OF THE 50S. BY THE END OF THE DAY THURSDAY...EXPECT SYNOPTIC COLD FRONT TO BE OVER SOUTHEAST OKLAHOMA...WITH A GRADUALLY SOUTHWARD MOVEMENT OF THE FRONT THURSDAY NIGHT AND FRIDAY...BEFORE POPS EXIT THE AREA LATE FRIDAY OR EARLY SATURDAY. DURING THESE PERIODS...HAVE DISCOUNTED THE SLOWER GFS SOLUTION WHICH ALSO APPEARS TO SUFFER SEVERE CONVECTIVE FEEDBACK PROBLEMS AS IT PROGRESSES THROUGH THE FORECAST AREA. SATURDAY THROUGH TUESDAY IS EXPECTED TO BE A PERIOD OF MOISTURE AND INSTABILITY RECOVERY. THE CONSENSUS OF THE MEDIUM RANGE MODELS SUGGESTS SURFACE HIGH WILL CONTINUE TO BUILD INTO THE AREA FRIDAY NIGHT AND SATURDAY...BEFORE ERODING TO THE WEST AS WEST TO SOUTHWEST MID/UPPER LEVEL FLOW INCREASES OVER THE SOUTHERN ROCKIES. LOWER LEVEL SOUTHERLY FLOW SHOULD INCREASE BY SATURDAY NIGHT/SUNDAY...WITH THE POTENTIAL FOR A NEW DRYLINE OVER THE TEXAS PANHANDLE...OR HIGH BASED ISENTROPIC LIFT -SHRA/TS OCCURRING NORTH OF THE SURFACE TEMP/DEWPT GRADIENT. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 67 86 64 70 / 40 20 40 70 HOBART OK 66 92 61 68 / 30 10 40 60 WICHITA FALLS TX 66 89 68 80 / 40 10 30 60 GAGE OK 62 87 51 57 / 20 20 70 40 PONCA CITY OK 67 84 58 64 / 30 20 70 60 DURANT OK 67 85 71 81 / 50 20 30 70 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ JAMES ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 332 PM CDT TUE MAY 11 2004 .DISCUSSION... SHORTWAVE TROUGH NEAR ABILENE...BEST MONITORED WITH 600 MB RUC... WILL ADVANCE SLOWLY NORTHEASTWARD...REACHING SOUTHEAST OKLAHOMA BY 06Z. DIFFERENTIAL HEATING AND A WEAK CAPPING INVERSION HAVE ALREADY BEEN SUFFICIENT FOR ABOUT 30 PERCENT AREAL COVERAGE NEAR AND NORTH ITS TRACK. WILL INCLUDE 30 TO 50 POPS THIS EVENING ALONG AND EAST OF INTERSTATE 44...WITH ACTIVITY EXPECTED TO DIMINISH SHORTLY AFTER SUNSET. AS THE TROUGH EXITS THE REGION AFTER MIDNIGHT...850 TO 700 MB FLOW IS EXPECTED TO VEER IN ITS WAKE...WHICH MAY SUPPORT ANOTHER SLIGHT CHANCE OF HIGH BASED -SHRA/TS LATER IN THE NIGHT AS THE LOW LEVEL JET DEVELOPS...AFFECTING AREAS MAINLY ALONG AND EAST OF INTERSTATE 35. DEVELOPING DRYLINE FROM EASTERN COLORADO INTO EASTERN NEW MEXICO IS EXPECTED TO BE ANOTHER AREA TO MONITOR FOR CONVECTIVE INITIATION OVER THE NEXT FEW HOURS...BEFORE DIMINISHED HEATING ALLOWS THE CAPPING INVERSION TO REINTENSIFY. AVERAGE STORM MOTIONS ACROSS THIS REGION WILL CONTAIN A SLIGHTLY MORE EASTWARD COMPONENT AND THUS STAND A SLIGHTLY BETTER CHANCE OF MAKING IT INTO WESTERN PARTS OF THE FORECAST AREA BEFORE ENDING TOWARD MIDNIGHT. FOR WEDNESDAY...CONCERN SHIFTS NORTHWESTWARD WHERE RUC/ETA MODEL INITIALIZATIONS ARE IN CLOSEST AGREEMENT WITH 12Z UPPER AIR OBSERVATIONS...WHEREAS THE GFS QUICKLY AMPLIFIES...PERHAPS OVERAMPLIFIES...SHORTWAVE TROUGH DEVELOPING THIS MORNING OVER WASHINGTON/OREGON. ALTHOUGH VERY FAR AWAY...EVOLUTION IN THIS AREA MAY PLAY A PIVOTAL ROLE WITH REGARDS TO FRONT AND SURFACE LOW POSITIONS BY LATE WEDNESDAY. HAVE RELIED HEAVILY ON RUC THROUGH THE NEXT 12 HRS...THEN FOLLOWED THE ETA THEREAFTER...WHICH SHOWS AN INITIAL SURGE OF THE COOLER AIR OVER THE NORTHERN PLAINS ENTERING NORTHWEST OKLAHOMA EARLY WEDNESDAY...WITH THE SURFACE LOW REORGANIZING WEST OR SOUTHWESTWARD FROM THE CENTRAL PLAINS LATE IN THE DAY. DURING THIS PERIOD...EXPECT EARLY MORNING -TSRA OVER THE EASTERN ONE THIRD OF THE AREA TO END...AS A STRONG CAPPING INVERSION BUILDS IN ADVANCE OF THE APPROACHING LONG WAVE TROUGH. CONVECTIVE INITIATION IS EXPECTED TO OCCUR LATE WEDNESDAY ALONG THE EVOLVING FRONTAL BOUNDARY OVER KANSAS...WITH ADDITIONAL DEVELOPMENT OCCURRING FARTHER WESTWARD NEAR REORGANIZING SURFACE LOW...WHERE MOIST UPSLOPE FLOW WILL BE INCREASING. EXPECT A LARGE SLOW MOVING MCS TO DEVELOP OVER SOUTHEAST COLORADO...SOUTHWEST KANSAS...AND THE OKLAHOMA PANHANDLE...WITH EVOLUTION OCCURRING EAST SOUTHEASTWARD ALONG AND JUST SOUTH OF THE KANSAS/OKLAHOMA STATE WEDNESDAY NIGHT. THIS SCENARIO CONSIDERS THAT THE COLD FRONT MAY BE FARTHER SOUTH OR MOVING SOUTH FASTER THAN DEPICTED BY THE MODELS...AND THAT THE ETA CONVECTIVE PARAMETERIZATION DOES NOT FACTOR EVAPORATIVE COOLING AND/OR CONVECTIVE OUTFLOW IN REDIRECTION OF AN MCS. MCS WILL LIKELY BE IN PROGRESS OVER PARTS OF THE FORECAST AREA THURSDAY MORNING...WITH THURSDAY'S FORECAST DOMINATED BY THE MESOSCALE. HAVE CONTINUED WITH HIGH POPS NEAR AND SOUTHEAST OF THE EXPECTED MCS POSITION THURSDAY MORNING WITH CONVECTION LIKELY ONGOING ALL DAY. OUTFLOW BOUNDARY MAY PUSH EFFECTIVE BOUNDARY SOUTHWARD INTO TEXAS...WITH POTENTIAL FOR SEVERE CONFINED TO NEAR THE RED RIVER AND AREAS SOUTH. OTHERWISE EXPECT COOL AND NEARLY SATURATED LOWER LEVEL AIR TO BE FLOWING UPSLOPE OVER NORTHWEST OKLAHOMA AND PORTIONS OF THE OKLAHOMA/TEXAS PANHANDLES...WITH HIGH TEMPS THURSDAY POSSIBLY NOT GETTING OUT OF THE 50S. BY THE END OF THE DAY THURSDAY...EXPECT SYNOPTIC COLD FRONT TO BE OVER SOUTHEAST OKLAHOMA...WITH A GRADUALLY SOUTHWARD MOVEMENT OF THE FRONT THURSDAY NIGHT AND FRIDAY...BEFORE POPS EXIT THE AREA LATE FRIDAY OR EARLY SATURDAY. DURING THESE PERIODS...HAVE DISCOUNTED THE SLOWER GFS SOLUTION WHICH ALSO APPEARS TO SUFFER SEVERE CONVECTIVE FEEDBACK PROBLEMS AS IT PROGRESSES THROUGH THE FORECAST AREA. SATURDAY THROUGH TUESDAY IS EXPECTED TO BE A PERIOD OF MOISTURE AND INSTABILITY RECOVERY. THE CONSENSUS OF THE MEDIUM RANGE MODELS SUGGESTS SURFACE HIGH WILL CONTINUE TO BUILD INTO THE AREA FRIDAY NIGHT AND SATURDAY...BEFORE ERODING TO THE WEST AS WEST TO SOUTHWEST MID/UPPER LEVEL FLOW INCREASES OVER THE SOUTHERN ROCKIES. LOWER LEVEL SOUTHERLY FLOW SHOULD INCREASE BY SATURDAY NIGHT/SUNDAY...WITH THE POTENTIAL FOR A NEW DRYLINE OVER THE TEXAS PANHANDLE...OR HIGH BASED ISENTROPIC LIFT -SHRA/TS OCCURRING NORTH OF THE SURFACE TEMP/DEWPT GRADIENT. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 67 86 64 70 / 40 20 40 70 HOBART OK 66 92 61 68 / 30 10 40 60 WICHITA FALLS TX 66 89 68 80 / 40 10 30 60 GAGE OK 62 87 51 57 / 20 20 70 40 PONCA CITY OK 67 84 58 64 / 30 20 70 60 DURANT OK 67 85 71 81 / 50 20 30 70 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ JAMES ok AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE NORMAN OK 122 PM CDT TUE MAY 11 2004 RADAR/STLT TRENDS INDICATE THE CENTRAL TEXAS MCV IS TRENDING A LITTLE MORE TO THE NORTH WHICH WILL ENHANCE SHWR/TSTM POSSIBILITIES OVER MAINLY SOUTHERN OKLAHOMA INTO PORTIONS OF WESTERN NORTH TEXAS. WILL UPDATE FORECAST TO RAISE POPS OVER THE SOUTH. ALSO INCLUDED ISOLATED ACTIVITY IN CENTRAL OKLAHOMA FOR THE AFTERNOON. CJS && ________________________________________________ 1055 AM CDT TUE MAY 11 2004 MCV NEAR ABILENE AT MID MORNING WILL CONTINUE MOVING NORTHEAST TODAY. RUC AND ETA DIFFER ON THE EXACT TRACK OVER THE NEXT SEVERAL HOURS WITH ETA BRINGING THE MCV MORE NORTHEAST. EITHER SOLUTION SHOULD PROVIDE THE OPPORTUNITY FOR SCATTERED SHWRS/TSTMS THIS AFTERNOON OVER THE SOUTH... ALTHOUGH IF ETA SOLUTION HOLDS... MAY NEED TO PULL PCPN CHANCES A LITTLE FARTHER NORTH THAT WE CURRENTLY HAVE. MORNING SOUNDING DID NOT INDICATE MUCH OF A CAP... SO IT WON'T TAKE A LOT OF FORCING TO GENERATE SOME SHWRS/TSTMS. WILL NUDGE UP POPS OVER THE FAR SOUTH FOR THE AFTERNOON. ELSEWHERE... THE DRYLINE WAS WELL BACK INTO EASTERN NEW MEXICO AT MID MORNING. EXPECT IT TO MIX OUT ONLY INTO FAR WESTERN TEXAS THIS AFTERNOON. WILL LEAVE IN LOW POPS FOR LATE AFTN/TNGT OVER THE FAR WEST FOR THE POSSIBILITY THAT SOME OF THIS ACTIVITY COULD GET INTO THE AREA. STORM STEERING FLOW WILL BE A LITTLE STRONGER TODAY THAN WHAT WE'VE SEEN THE PAST SEVERAL DAYS... ALTHOUGH WITH THE DRYLINE REMAINING SO FAR WEST... BELIEVE 20 PCT POPS IS PLENTY HIGH. ALSO MADE A FEW MINOR ADJUSTMENTS TO TEMPS IN AREAS WHERE THICKER CLOUD COVER DURING THE MORNING HAS SLOW THE RATE OF WARMING. CJS && ________________________________ 515 AM CDT TUE MAY 11 2004 .UPDATE... WILL UPDATE 1ST PERIOD OF ZONE FORECAST TO ACCOUNT FOR NORTH-CENTRAL DOWN THROUGH CENTRAL OKLAHOMA CONVECTIVE DEVELOPMENT. LINEAR FORMATION APPEARS TO BE INDUCED BY MOIST LOW LEVEL JET INTERACTING WITH 850-700MB THERMAL RIBBON. EXPECT ACTIVITY TO CONTINUE THROUGH SUNRISE AND SHIFT NORTHEAST WITH TIME. NOT REAL SURE HOW FAR SOUTH IT WILL DEVELOP...SO WILL ADD A COUNTY OR TWO SOUTH OF CURRENT ACTIVITY. 11 && 341 AM .DISCUSSION... A SMALL AREA OF A FEW THUNDERSTORMS HAD DEVELOPED NEAR/ALONG THE WESTERN OK/TEXAS PANHANDLE STATE LINE EARLY THIS MORNING. THESE STORMS HAVE DIMINISHED AND FURTHER DEVELOPMENT IN THIS AREA IS NOT EXPECTED THIS MORNING. A LARGER AREA OF THUNDERSTORMS HAS DEVELOPED IN THE BIG BEND AREA OF TX OVERNIGHT AHEAD OF A SHORTWAVE THAT IS EXPECTED TO MOVE ACROSS TX TODAY. SHOWERS AND THUNDERSTORMS AHEAD OF THIS WAVE COULD POSSIBLY AFFECT SOUTHERN PORTIONS OF FA TODAY. THERE IS ALSO A CHANCE OF THUNDERSTORMS THIS AFTN/EVENING IN PORTIONS OF WESTERN OK. IF CONVECTION DEVELOPS ON A DRYLINE POSITIONED IN THE TX PANHANDLE...SOME OF THESE STORMS COULD MOVE INTO WESTERN OK BEFORE DISSIPATING. UPR TROUGH CURRENTLY DIGGING ACROSS THE WESTERN U.S. IS EXPECTED TO MOVE EAST OVER THE NEXT FEW DAYS. A COLD FRONT IS ALSO EXPECTED TO MOVE ACROSS THE FA LATER THIS WEEK. HOWEVER...MODELS CAN NOT AGREE ON TIMING OF FRONT. ETA HAS SFC LOW AND FRONT INTO SW OK BY THURS MORNING. GFS IS SLOWER WITH FRONT IN NW OK THURS MORNING. FRONTAL POSITION BY THIS TIME COULD BE DEPENDENT ON HOW MUCH CONVECTION DEVELOPS WED WHICH COULD PUSH FRONT SOUTH FASTER THAN PROGGED. GFS ALSO SEEMS TO BE SUFFERING FROM SOME CONVECTIVE FEEDBACK. WITH UNCERTAINTIES HAVE NOT MADE ANY MAJOR CHANGES TO POPS. TEMP FORECAST ALSO BECOMES DIFFICULT. THUNDERSTORM CHANCES EXPECTED TO BEGIN WED AFTN AND CONT INTO THE WEEKEND WITH UPR TROUGH APPROACHING AND MOVING ACROSS THE CENTRAL U.S. AND THE FRONT IN/NEAR THE FA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 82 65 85 66 / 20 10 10 40 HOBART OK 84 64 89 64 / 10 20 20 30 WICHITA FALLS TX 83 66 88 66 / 20 10 10 30 GAGE OK 85 62 87 58 / 20 20 30 30 PONCA CITY OK 82 66 83 65 / 30 10 30 40 DURANT OK 81 67 84 67 / 20 20 20 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 25 ok AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE NORMAN OK 1055 AM CDT TUE MAY 11 2004 MCV NEAR ABILENE AT MID MORNING WILL CONTINUE MOVING NORTHEAST TODAY. RUC AND ETA DIFFER ON THE EXACT TRACK OVER THE NEXT SEVERAL HOURS WITH ETA BRINGING THE MCV MORE NORTHEAST. EITHER SOLUTION SHOULD PROVIDE THE OPPORTUNITY FOR SCATTERED SHWRS/TSTMS THIS AFTERNOON OVER THE SOUTH... ALTHOUGH IF ETA SOLUTION HOLDS... MAY NEED TO PULL PCPN CHANCES A LITTLE FARTHER NORTH THAT WE CURRENTLY HAVE. MORNING SOUNDING DID NOT INDICATE MUCH OF A CAP... SO IT WON'T TAKE A LOT OF FORCING TO GENERATE SOME SHWRS/TSTMS. WILL NUDGE UP POPS OVER THE FAR SOUTH FOR THE AFTERNOON. ELSEWHERE... THE DRYLINE WAS WELL BACK INTO EASTERN NEW MEXICO AT MID MORNING. EXPECT IT TO MIX OUT ONLY INTO FAR WESTERN TEXAS THIS AFTERNOON. WILL LEAVE IN LOW POPS FOR LATE AFTN/TNGT OVER THE FAR WEST FOR THE POSSIBILITY THAT SOME OF THIS ACTIVITY COULD GET INTO THE AREA. STORM STEERING FLOW WILL BE A LITTLE STRONGER TODAY THAN WHAT WE'VE SEEN THE PAST SEVERAL DAYS... ALTHOUGH WITH THE DRYLINE REMAINING SO FAR WEST... BELIEVE 20 PCT POPS IS PLENTY HIGH. ALSO MADE A FEW MINOR ADJUSTMENTS TO TEMPS IN AREAS WHERE THICKER CLOUD COVER DURING THE MORNING HAS SLOW THE RATE OF WARMING. CJS && ________________________________ 515 AM CDT TUE MAY 11 2004 .UPDATE... WILL UPDATE 1ST PERIOD OF ZONE FORECAST TO ACCOUNT FOR NORTH-CENTRAL DOWN THROUGH CENTRAL OKLAHOMA CONVECTIVE DEVELOPMENT. LINEAR FORMATION APPEARS TO BE INDUCED BY MOIST LOW LEVEL JET INTERACTING WITH 850-700MB THERMAL RIBBON. EXPECT ACTIVITY TO CONTINUE THROUGH SUNRISE AND SHIFT NORTHEAST WITH TIME. NOT REAL SURE HOW FAR SOUTH IT WILL DEVELOP...SO WILL ADD A COUNTY OR TWO SOUTH OF CURRENT ACTIVITY. 11 && 341 AM .DISCUSSION... A SMALL AREA OF A FEW THUNDERSTORMS HAD DEVELOPED NEAR/ALONG THE WESTERN OK/TEXAS PANHANDLE STATE LINE EARLY THIS MORNING. THESE STORMS HAVE DIMINISHED AND FURTHER DEVELOPMENT IN THIS AREA IS NOT EXPECTED THIS MORNING. A LARGER AREA OF THUNDERSTORMS HAS DEVELOPED IN THE BIG BEND AREA OF TX OVERNIGHT AHEAD OF A SHORTWAVE THAT IS EXPECTED TO MOVE ACROSS TX TODAY. SHOWERS AND THUNDERSTORMS AHEAD OF THIS WAVE COULD POSSIBLY AFFECT SOUTHERN PORTIONS OF FA TODAY. THERE IS ALSO A CHANCE OF THUNDERSTORMS THIS AFTN/EVENING IN PORTIONS OF WESTERN OK. IF CONVECTION DEVELOPS ON A DRYLINE POSITIONED IN THE TX PANHANDLE...SOME OF THESE STORMS COULD MOVE INTO WESTERN OK BEFORE DISSIPATING. UPR TROUGH CURRENTLY DIGGING ACROSS THE WESTERN U.S. IS EXPECTED TO MOVE EAST OVER THE NEXT FEW DAYS. A COLD FRONT IS ALSO EXPECTED TO MOVE ACROSS THE FA LATER THIS WEEK. HOWEVER...MODELS CAN NOT AGREE ON TIMING OF FRONT. ETA HAS SFC LOW AND FRONT INTO SW OK BY THURS MORNING. GFS IS SLOWER WITH FRONT IN NW OK THURS MORNING. FRONTAL POSITION BY THIS TIME COULD BE DEPENDENT ON HOW MUCH CONVECTION DEVELOPS WED WHICH COULD PUSH FRONT SOUTH FASTER THAN PROGGED. GFS ALSO SEEMS TO BE SUFFERING FROM SOME CONVECTIVE FEEDBACK. WITH UNCERTAINTIES HAVE NOT MADE ANY MAJOR CHANGES TO POPS. TEMP FORECAST ALSO BECOMES DIFFICULT. THUNDERSTORM CHANCES EXPECTED TO BEGIN WED AFTN AND CONT INTO THE WEEKEND WITH UPR TROUGH APPROACHING AND MOVING ACROSS THE CENTRAL U.S. AND THE FRONT IN/NEAR THE FA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 82 65 85 66 / 20 10 10 40 HOBART OK 84 64 89 64 / 10 20 20 30 WICHITA FALLS TX 83 66 88 66 / 20 10 10 30 GAGE OK 85 62 87 58 / 20 20 30 30 PONCA CITY OK 82 66 83 65 / 30 10 30 40 DURANT OK 81 67 84 67 / 20 20 20 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 25 ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 950 PM EDT TUE MAY 11 2004 PER LATEST RUC RUN AND RADAR DATA...IT APPEARS ONLY REMAINING CHANCE OF THUNDERSTORMS IS TOWARD NORTHWEST PA AS THE BOUNDARY MOVES THROUGH THAT AREA. REST UNCHANGED. ...GIORDANO .PBZ WATCHES/WARNINGS/ADVISORIES... PA...NONE. OH...NONE. WV...NONE. MD...NONE. && $$ pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 1023 AM CDT TUE MAY 11 2004 .DISCUSSION... ACROSS THE MID SOUTH THIS MORNING SKIES WERE PARTLY CLOUDY WITH LIGHT SOUTHERLY WINDS AND TEMPS CLIMBING THROUGH THE 70S. 14Z RUC ANALYSIS INDICATES A 1000-500 MB MOISTURE MINIMUM CENTERED OVER THE MID SOUTH WHILE DEEPER MOISTURE LIES ACRS SRN AR AND NRN LA. SCT SHOWERS HAVE DEVELOPED IN THESE AREAS THIS MORNING ASSOCD WITH SOME WEAK LIFT...PROBABLY CAUSED BY A WEAK SHORTWAVE. CAPES ALREADY 1000-1500 J/KG ACRS WRN HALF OF THE CWFA. HEATING THIS AFTN WL PUSH THESE VALUES TO 2000+ J/KG. DEEPER MOISTURE WILL SPREAD NORTHWARD THIS AFTN. SOME WEAK LIFT AND AFTN HEATING/INSTABILITY SHOULD BE SUFFICIENT TO TRIGGER SCT TSRAS THAT WL CONT INTO THE EARLY EVENING. && .MEG...WATCHES/WARNINGS/ADVISORIES... AR...NONE. MS...NONE. MO...NONE. TN...NONE. && $$ SJM tn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 900 PM CDT TUE MAY 11 2004 .UPDATE... CONVECTION ON THE WANE ALONG AND BEHIND RETREATING DRY LINE WITH LOSS OF DAYTIME HEATING AND PASSING OF MID LEVEL SHORT WAVE. WILL UPDATE ZONES/GRIDS TO REMOVE MENTION OF THUNDER THE REST OF THE NIGHT AND TAKE OUT EVENING WORDING. TWEAKED DEW POINT SKY CONDITION AND WIND GRIDS. WILL SEND UPDATED ZFP/SFT/PFM SHORTLY. 12 .SHORT TERM... SKIES HAVE CLEARED NICELY OVER THE AREA ALLOWING THE AREA TO DESTABILIZE. DRYLINE FINALLY STARTED MAKING PROGRESS EAST BY 18Z TODAY...AS KCNM WINDS TURNED TO THE WEST AND THE DEWPOINT DROPPED 10F DEGREES. EXPECT THE DRYLINE TO MAKE PRETTY GOOD PROGRESS TO THE EAST AS MIXING INCREASES. WHITE SANDS PROFILER IS SHOWING WEST TO SOUTHWEST WINDS OF 15KT TO 20KT THROUGH 700MB...AND THIS SHOULD CONTINUE TO HELP MIX THE DRYLINE TO THE EAST THROUGH THE LATE AFTERNOON HOURS. RUC DATA ANALYZED A SHORTWAVE OVER SOUTHERN NM AND NORTHERN CHIHUAHUA WHICH WILL MOVE EAST OUT OVER WEST TX THIS EVENING. THIS WILL COMBINE WITH CAPES OF AROUND 1200J/KG AND THE DRYLINE TO INITIATE CONVECTION FROM OUR CWA NORTHWARD...MOST LIKELY IN OUR NORTH AND NORTHEASTERN ZONES. WITH MUCH BETTER VERTICAL SHEAR OVER THE AREA TODAY...EXPECT SOME OF THESE THUNDERSTORMS TO BE BETTER ORGANIZED THAN THE PAST FEW DAYS AND APPROACH SEVERE LEVELS...WITH LARGE HAIL AND DAMAGING WINDS BEING THE MAIN THREATS FROM THESE STORMS. THERE WILL ALSO BE BETTER MOVEMENT TO THESE THUNDERSTORMS TODAY THAN THERE HAS BEEN IN THE PAST FEW DAYS AS WINDS ALOFT AND THROUGH THE MID-LEVELS HAVE BEEN INCREASING OVER THE PAST 24 HOURS. WILL NOT MAKE ANY BIG CHANGES TO THE LOW TEMPERATURES TONIGHT AS THE DRYLINE IS EXPECTED TO MAKE SOME PROGRESS BACK TO THE WEST. .LONG TERM... LONGWAVE TROUGH WILL BE ESTABLISHED OVER THE WESTERN CONUS WEDNESDAY...BEFORE PROGRESSING EAST AND MINORING OUT OVER THE CENTRAL PLAINS BY WEEK/S END. NEARLY ZONAL FLOW ALOFT WILL PREVAIL THEREAFTER WITH OCCASIONAL WEAK SHORTWAVE TROUGHS TRANSLATING EASTWARD OVER THE AREA THROUGH THE END OF THE PERIOD. LOW LEVEL MOISTURE WILL PUSH EAST OF THE CWA WEDNESDAY AFTERNOON ON WEST/SOUTHWEST FLOW ALOFT AND AT THE SURFACE...PRECLUDING THE ADDITION OF ANY POPS FOR WEDNESDAY AND WEDNESDAY NIGHT. ANOTHER SHORTWAVE TROUGH WILL HEAD TOWARD THE CWA ON THURSDAY. EXPECT DRYLINE TO SETUP OVER THE EASTERN ZONES THURSDAY WHICH WILL PROVIDE A LOW LEVEL FOCUS FOR THUNDERSTORM DEVELOPMENT AS AFOREMENTIONED SHORTWAVE TROUGH MOVES OVERHEAD. THEREFORE...HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS FOR THE EASTERNMOST ZONES THURSDAY AFTERNOON AND EVENING. SHEAR LOOKS SUFFICIENT FOR ORGANIZED CONVECTION THURSDAY...SO CONSIDERING THE INSTABILITY WE/LL HAVE...SOME SEVERE STORMS WILL BE POSSIBLE. AREAL EXTENT STILL IN QUESTION...SO WILL NOT MENTION SEVERE WORDING IN THE ZONES AT THIS TIME. MOISTURE LINGERS OVER THE EASTERN ZONES FRIDAY AS ANOTHER SHORTWAVE TROUGH ROUNDS THE BASE OF THE LONGWAVE TROUGH. IN ADDITION...A COLD FRONT WILL PUSH INTO THE AREA FRIDAY MORNING...AND PROBABLY PUSH SOUTHWEST OF THE PECOS RIVER BY FRIDAY AFTERNOON. MID LEVEL SUPPORT APPEARS TO BE LACKING...BUT HAVE ADDED A CHANCE OF TSRA TO THE LOWER TRANS PECOS...AND A SLIGHT CHANCE FROM THE BIG BEND REGION TO THE WESTERN LOW ROLLING PLAINS. WENT AHEAD AND MENTIONED THUNDER IN ALL OF THESE LOCATIONS AS GFS INDICATING ATMOSPHERE TO BE AT LEAST MARGINALLY UNSTABLE...EVEN BEHIND THE FRONT INTO EARLY AFTERNOON. ADDED...BUT RELEGATED...A SLIGHT CHANCE OF TSRA FRIDAY EVENING TO THE BIG BEND REGION DESPITE UPPER TROUGH BEING DEPICTED EAST OF THE AREA BY THEN SINCE THERE ARE SOME INDICATIONS A WEAK SHORTWAVE WILL BE TRAILING THE MAIN TROUGH. LEFT A FEW SHOWERS IN THE BIG BEND AREA SATURDAY MORNING...BEFORE DROPPING ALL POPS SATURDAY NIGHT. REFINED THE CHANCES OF SHRA/TSRA SUNDAY THROUGH MONDAY NIGHT AS GFS AND ECMWF DEPICTING UPSLOPE FLOW...WAA OVER SLIGHTLY COOLER AIRMASS...AND A SERIES OF WEAK SHORTWAVES PARADING OVER THE AREA DURING THIS TIME. WARMEST TEMPERATURES SO FAR THIS YEAR APPEAR TO BE IN ORDER WEDNESDAY AS H85 THERMAL RIDGE EXPANDS OVER THE AREA...AND WILL BE AIDED IN WARMING TEMPERATURES BY DOWNSLOPE WINDS. ON THURSDAY... TEMPS WILL BE FAIRLY SIMILAR TO READINGS WEDNESDAY...EXCEPT FOR THE EXTREME EASTERN ZONES WHERE MOISTURE EXPECTED TO INFRINGE. WILL MAKE MINOR TWEAKS WEDNESDAY AND A FEW MORE ON THURSDAY. ON FRIDAY...WILL HAVE TO COOL HIGHS...ESPECIALLY OVER THE NORTHEAST HALF OF THE CWA DUE TO COLD FRONT. WILL TRY NOT TO GET TOO CARRIED AWAY...SINCE IT/S ALMOST MID MAY. TEMPERATURES WARM GRADUALLY INTO EARLY NEXT WEEK. THANKS FOR COORD LUB...SJT. && .PRELIMINARY POINT TEMPS/POPS... BIG SPRING TX 65 92 62 89 / 20 10 0 10 CARLSBAD NM 60 91 60 90 / 0 0 0 0 DRYDEN TX 64 92 67 90 / 20 10 10 20 FORT STOCKTON TX 64 93 63 91 / 20 0 0 10 GUADALUPE PASS TX 58 84 58 84 / 0 0 0 0 HOBBS NM 61 92 60 91 / 20 0 0 0 MARFA TX 52 86 50 85 / 20 0 0 0 MIDLAND INTL AIRPORT TX 63 93 62 88 / 20 10 0 10 ODESSA TX 63 92 61 89 / 20 0 0 10 WINK TX 62 99 62 96 / 20 0 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... TX...NONE. NM...NONE. && $$ 20/67 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 330 PM CDT TUE MAY 11 2004 .SHORT TERM... APPROACHING UPPER TROF AND INCREASING SOUTHWEST FLOW ALOFT CAUSING SURFACE PRESSURE FALLS ACROSS WESTERN GREAT PLAINS THIS AFTERNOON. DRYLINE ORGANIZING ACROSS WESTERN PANHANDLE AND EXTREME NORTHWESTERN SOUTH PLAINS...THEN TAKING INTERESTING KINK TO THE SOUTH-SOUTHEAST ACROSS SOUTHWESTERN SOUTH PLAINS. THIS IS BECAUSE OF LAST EVENINGS RAINFALL ACROSS THE CENTRAL SOUTH PLAINS THAT HAS LIMITED THE SURFACE WARMING AND DEPTH OF MIXING SLIGHTLY HOLDING MORE SOUTHEAST SURFACE COMPONENT AND THUS APPARENTLY CREATING THE DRYLINE BULGE. SURFACE CONVERGENCE VALUES INCREASING FROM WEST-NORTHWEST COUNTIES TO SOUTH CENTRAL COUNTIES...WITH AN APPARENT MAX SHOWING UP ACROSS LYNN AND SOUTHWEST LUBBOCK COUNTIES WHERE HORIZONTAL VORTICITY ROLLS SHOWING UP BEST THROUGH GROWING CUMULUS FIELD THIS AREA. SEVERE INDICES ARE GENERALLY FAVORABLE THIS AFTERNOON WITH MODERATE CAPES AND INCREASING SHEAR...ESPECIALLY IN LOWEST 3KM WHERE HELICITY VALUES HAVE GONE UP AS FORECAST THIS MORNING FROM BOTH THE ETA AND RUC MODELS. 18Z REESE SOUNDING COURTESY OF THE TTU WEST TEXAS MESONET GROUP INDICATED STILL ABOUT 4.5 DEGREES CENTIGRADE OF WARMING REQUIRED TO BREAK LOW LEVEL CAP...BUT WE HAVE ALREADY MADE UP 2/3 OF THAT BY MID AFTERNOON. ALL OF THIS TO SAY WE STILL SUPPORT PREVIOUS RISK OF SEVERE OVER THE NEXT 6-8 HOURS WITH POTENTIAL FOR A FEW ROTATING SUPERCELLS SHOULD LONG LASTING UPDRAFTS GET GOING. SCENARIO WOULD OTHERWISE FAVOR LINEAR OR CLUSTER MULTICELL DEVELOPMENT WITH TYPICAL HIGH BASED PULSE SEVERE THREAT. ANY THUNDERSTORMS SHOULD MOVE STEADILY EAST THIS EVENING WITH DRIER AIR FOLLOWING OVERNIGHT INTO WEDNESDAY. STRONGER SOUTHWEST FLOW EXPECTED TO MIX DRYLINE FURTHER EAST BY WEDNESDAY AFTERNOON WITH WARM DOWNSLOPE AND DRYING COMPONENT DOMINATING. MINOR CHANGES TO INDICATE SLIGHTLY HIGHER CHANCE OF PRECIPITATION SOUTHWEST ZONES EARLY THIS EVENING. OTHERWISE FEW CHANGES OVERALL FROM PREVIOUS FORECAST. MCQUEEN .LONG TERM... ABUNDANT MOIST LOW LEVEL FLOW WILL GIVE WAY TO RAPID DRYING IN THE WAKE OF WEST TO SOUTHWEST FLOW ALONG THE DRYLINE/MOISTURE POOLING INTERFACE. ETA MODEL HAS A GOOD HANDLE ON THIS FEATURE. WENT WITH A DRYING TREND AND LOWERED POPS FROM NORTHWEST TO SOUTHEAST ACROSS THE CWA FOR WEDNESDAY. ON THE LARGER SCALE...LARGE UPPER LEVEL TROUGH WILL CONTINUE TO MOVE SLOWLY EAST ACROSS THE CENTRAL AND NORTHERN PLAINS STATES THROUGH THE MID RANGE PERIOD. SURFACE COLD FRONTAL BOUNDARY SHOWING UP WELL ON MID RANGE MODELS TODAY. CONSENSUS BRINGS THE SURFACE FRONT INTO THE NORTHERN PANHANDLE BETWEEN 00Z AND 06Z FRIDAY WITH GOOD LOW LEVEL CONVERGENCE AXIS SETTING UP ROUGHLY ALONG AND SOUTH OF A KBWS TO KPTS TO KJTS TO KSPS LINE. WITH LOW LEVEL DYNAMICS IN PLACE....WEAK SHORTWAVE DYNAMICS AND COOL AIR RUSHING IN ALOFT...INCREASED POPS ACROSS OUR CWA...ESPECIALLY CENTRAL AND EASTERN SECTIONS. KEPT LOW POPS OVER SOUTHEAST PORTIONS THROUGH EARLY SATURDAY MORNING TO CONSIDER FRONTAL SLOWING AND OR STRATIFORM TYPE RAIN BEHIND THE FROPA. BY SUNDAY...LOW LEVEL FLOW INCREASES OUT OF THE SOUTH AND SOUTHWEST AS FRONTAL BOUNDARY STALLS SOUTH OF THE CWA AND EVENTUALLY WASHES OUT. SLIGHT CHANCES FOR THUNDERSTORMS ALONG DRYLINE SETUP LATE MONDAY BUT...FOR THE MOST PART DRY SOUTHWEST FLOW AND LOW DEWPOINTS WILL BE THE RULING ACROSS MOST OF THE REGION THROUGH THE DAYS 5 TO 7 PERIOD. HIGH PRESSURE ALOFT WILL BE FOLLOWED BY ANOTHER LARGE UPPER TROUGH MOVING INTO THE FOUR CORNERS REGION BY NEXT THURSDAY. WIDELSKI && .PRELIMINARY POINT TEMPS/POPS... FRIONA 53 90 53 78 / 30 10 10 10 TULIA 57 90 59 79 / 30 10 10 10 PLAINVIEW 58 91 60 81 / 30 10 10 10 LEVELLAND 55 92 61 85 / 30 10 10 10 LUBBOCK 59 91 60 85 / 30 10 10 10 BROWNFIELD 56 92 61 86 / 30 10 10 10 CHILDRESS 63 93 63 81 / 30 10 10 30 SPUR 63 92 63 85 / 30 10 10 30 ASPERMONT 64 92 65 84 / 20 10 10 30 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 05/17 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 219 PM CDT TUE MAY 11 2004 .SHORT TERM... SKIES HAVE CLEARED NICELY OVER THE AREA ALLOWING THE AREA TO DESTABILIZE. DRYLINE FINALLY STARTED MAKING PROGRESS EAST BY 18Z TODAY...AS KCNM WINDS TURNED TO THE WEST AND THE DEWPOINT DROPPED 10F DEGREES. EXPECT THE DRYLINE TO MAKE PRETTY GOOD PROGRESS TO THE EAST AS MIXING INCREASES. WHITE SANDS PROFILER IS SHOWING WEST TO SOUTHWEST WINDS OF 15KT TO 20KT THROUGH 700MB...AND THIS SHOULD CONTINUE TO HELP MIX THE DRYLINE TO THE EAST THROUGH THE LATE AFTERNOON HOURS. RUC DATA ANALYZED A SHORTWAVE OVER SOUTHERN NM AND NORTHERN CHIHUAHUA WHICH WILL MOVE EAST OUT OVER WEST TX THIS EVENING. THIS WILL COMBINE WITH CAPES OF AROUND 1200J/KG AND THE DRYLINE TO INITIATE CONVECTION FROM OUR CWA NORTHWARD...MOST LIKELY IN OUR NORTH AND NORTHEASTERN ZONES. WITH MUCH BETTER VERTICAL SHEAR OVER THE AREA TODAY...EXPECT SOME OF THESE THUNDERSTORMS TO BE BETTER ORGANIZED THAN THE PAST FEW DAYS AND APPROACH SEVERE LEVELS...WITH LARGE HAIL AND DAMAGING WINDS BEING THE MAIN THREATS FROM THESE STORMS. THERE WILL ALSO BE BETTER MOVEMENT TO THESE THUNDERSTORMS TODAY THAN THERE HAS BEEN IN THE PAST FEW DAYS AS WINDS ALOFT AND THROUGH THE MID-LEVELS HAVE BEEN INCREASING OVER THE PAST 24 HOURS. WILL NOT MAKE ANY BIG CHANGES TO THE LOW TEMPERATURES TONIGHT AS THE DRYLINE IS EXPECTED TO MAKE SOME PROGRESS BACK TO THE WEST. .LONG TERM... LONGWAVE TROUGH WILL BE ESTABLISHED OVER THE WESTERN CONUS WEDNESDAY...BEFORE PROGRESSING EAST AND MINORING OUT OVER THE CENTRAL PLAINS BY WEEK/S END. NEARLY ZONAL FLOW ALOFT WILL PREVAIL THEREAFTER WITH OCCASIONAL WEAK SHORTWAVE TROUGHS TRANSLATING EASTWARD OVER THE AREA THROUGH THE END OF THE PERIOD. LOW LEVEL MOISTURE WILL PUSH EAST OF THE CWA WEDNESDAY AFTERNOON ON WEST/SOUTHWEST FLOW ALOFT AND AT THE SURFACE...PRECLUDING THE ADDITION OF ANY POPS FOR WEDNESDAY AND WEDNESDAY NIGHT. ANOTHER SHORTWAVE TROUGH WILL HEAD TOWARD THE CWA ON THURSDAY. EXPECT DRYLINE TO SETUP OVER THE EASTERN ZONES THURSDAY WHICH WILL PROVIDE A LOW LEVEL FOCUS FOR THUNDERSTORM DEVELOPMENT AS AFOREMENTIONED SHORTWAVE TROUGH MOVES OVERHEAD. THEREFORE...HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS FOR THE EASTERNMOST ZONES THURSDAY AFTERNOON AND EVENING. SHEAR LOOKS SUFFICIENT FOR ORGANIZED CONVECTION THURSDAY...SO CONSIDERING THE INSTABILITY WE/LL HAVE...SOME SEVERE STORMS WILL BE POSSIBLE. AREAL EXTENT STILL IN QUESTION...SO WILL NOT MENTION SEVERE WORDING IN THE ZONES AT THIS TIME. MOISTURE LINGERS OVER THE EASTERN ZONES FRIDAY AS ANOTHER SHORTWAVE TROUGH ROUNDS THE BASE OF THE LONGWAVE TROUGH. IN ADDITION...A COLD FRONT WILL PUSH INTO THE AREA FRIDAY MORNING...AND PROBABLY PUSH SOUTHWEST OF THE PECOS RIVER BY FRIDAY AFTERNOON. MID LEVEL SUPPORT APPEARS TO BE LACKING...BUT HAVE ADDED A CHANCE OF TSRA TO THE LOWER TRANS PECOS...AND A SLIGHT CHANCE FROM THE BIG BEND REGION TO THE WESTERN LOW ROLLING PLAINS. WENT AHEAD AND MENTIONED THUNDER IN ALL OF THESE LOCATIONS AS GFS INDICATING ATMOSPHERE TO BE AT LEAST MARGINALLY UNSTABLE...EVEN BEHIND THE FRONT INTO EARLY AFTERNOON. ADDED...BUT RELEGATED...A SLIGHT CHANCE OF TSRA FRIDAY EVENING TO THE BIG BEND REGION DESPITE UPPER TROUGH BEING DEPICTED EAST OF THE AREA BY THEN SINCE THERE ARE SOME INDICATIONS A WEAK SHORTWAVE WILL BE TRAILING THE MAIN TROUGH. LEFT A FEW SHOWERS IN THE BIG BEND AREA SATURDAY MORNING...BEFORE DROPPING ALL POPS SATURDAY NIGHT. REFINED THE CHANCES OF SHRA/TSRA SUNDAY THROUGH MONDAY NIGHT AS GFS AND ECMWF DEPICTING UPSLOPE FLOW...WAA OVER SLIGHTLY COOLER AIRMASS...AND A SERIES OF WEAK SHORTWAVES PARADING OVER THE AREA DURING THIS TIME. WARMEST TEMPERATURES SO FAR THIS YEAR APPEAR TO BE IN ORDER WEDNESDAY AS H85 THERMAL RIDGE EXPANDS OVER THE AREA...AND WILL BE AIDED IN WARMING TEMPERATURES BY DOWNSLOPE WINDS. ON THURSDAY... TEMPS WILL BE FAIRLY SIMILAR TO READINGS WEDNESDAY...EXCEPT FOR THE EXTREME EASTERN ZONES WHERE MOISTURE EXPECTED TO INFRINGE. WILL MAKE MINOR TWEAKS WEDNESDAY AND A FEW MORE ON THURSDAY. ON FRIDAY...WILL HAVE TO COOL HIGHS...ESPECIALLY OVER THE NORTHEAST HALF OF THE CWA DUE TO COLD FRONT. WILL TRY NOT TO GET TOO CARRIED AWAY...SINCE IT/S ALMOST MID MAY. TEMPERATURES WARM GRADUALLY INTO EARLY NEXT WEEK. THANKS FOR COORD LUB...SJT. && .PRELIMINARY POINT TEMPS/POPS... BIG SPRING TX 65 92 62 89 / 20 10 0 10 CARLSBAD NM 60 91 60 90 / 0 0 0 0 DRYDEN TX 64 92 67 90 / 20 10 10 20 FORT STOCKTON TX 64 93 63 91 / 20 0 0 10 GUADALUPE PASS TX 58 84 58 84 / 0 0 0 0 HOBBS NM 61 92 60 91 / 20 0 0 0 MARFA TX 52 86 50 85 / 20 0 0 0 MIDLAND INTL AIRPORT TX 63 93 62 88 / 20 10 0 10 ODESSA TX 63 92 61 89 / 20 0 0 10 WINK TX 62 99 62 96 / 20 0 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... TX...NONE. NM...NONE. && $$ 20/67 tx AREA FORECAST DISCUSSION...UPDATED FOR MIDDAY AVIATION NATIONAL WEATHER SERVICE FORT WORTH TX 1155 AM CDT TUE MAY 11 2004 .AVIATION... MCV CONTS MOVG SLOWLY TWDS WRN PTNS OF N TX TRACON...WHILE SEA BREEZE FEATURE IN SE TX MOVS NWD TWDS SRN SECTIONS OF TRACON WITH RADAR INDICATING NUMEROUS SHRA/TSRA ONGOING ALONG IT WITH DAYTIME HEATING. KACT SHOULD SEE ACTIVITY AFFECTING SITE BY 18Z/AFTER AND WILL HAVE VCTS W/PROB 30 GROUP THROUGH 23-00Z AS ABUNDANT MOISTURE/INSTABILITY MAY RESULT IN WET MICROBURST TYPE GSTS IN EXCESS OF 40 KT. FARTHER NWD ACROSS KDFW PTN OF TRACON XPCT AN INCRS IN SCT SHRA/TSRA THRU 00Z WITH HEATING. WILL INSERT VCTS/CB MENTION AS MCV APPROACHES. OTRW...CONT S/SELY FLOW 10-15 KTS/GSTS TO 20 KTS AT TIMES THRU 00Z. SFC WNDS SELY 5-15 KTS BY 01Z/AFTER AS SFC FLOW BECOMES SEMI-DECOUPLED FROM BL. VFR CONDS TO CONT THROUGH 06Z... OUTSIDE OF ANY TSRA...WITH MVFR CIGS RETURNING IN THE 06Z WED/AFTER PD ONCE AGAIN AS MODEST LLJ ENSUES. 05/ && .PREV PUBLIC UPDATE 1045 AM... MAIN SHORT TERM FORECAST CONCERN WILL BE POPS. ANALYSIS OF 12Z KFWD RAOB DATA SHOWS STRONG INSTABILITY WITH CAPE VALUES EXCEEDING 2000 J/KG. ADDITIONAL ANALYSES SUGGEST THAT A PLUME OF DEEP MOISTURE IS ORIENTED FROM SOUTH-CENTRAL TEXAS...INTO WESTERN/CENTRAL OKLAHOMA... WITH A WEAK MID-LEVEL VORT MAX ALSO NOTED ACROSS WEST TEXAS. GIVEN THIS DATA...WE WILL NEED TO UPDATE TO INCREASE POPS TO THE CHANCE CATEGORY FOR ALL AREAS. SHORT TERM GUIDANCE FROM THE RUC/MESOETA IS IN DECENT AGREEMENT ON MOVEMENT OF SOUTH TEXAS MCS...LOCATED BETWEEN KUVA-KCOT-KHDO...TO THE EAST LATER THIS AFTERNOON. HOWEVER...ITS EFFECTS ON THE ANTICIPATED WEATHER ACROSS ACROSS NORTH TEXAS SHOULD BE NEGLIGIBLE...WITH DEEP MOISTURE ALREADY IN PLACE ACROSS THE AREA. CLOUD COVER/SFC WIND/MAX TEMP GRIDS ALL LOOK OKAY...AND WE WILL NOT CHANGE THEM AT THIS POINT. 65/DD && .EARLY MORNING AVIATION 700 AM... A FEW LLJ STORMS NEAR ACT AROUND DAYBREAK. MCS OVER HILL COUNTRY CONTINUES MAKING PROGRESS EASTWARD. MCV STILL BACK TOWARD NEAR SJT. AS FEATURE APPROACHES DEEPER MOISTURE...FURTHER DEVELOPMENT POSSIBLE THROUGH CENTRAL TEXAS. 06Z AVN QUITE AGGRESSIVE WITH QPF. HAVE CHOSEN TO FOREGO TSRA/SHRA AT METRO TAF SITES...BUT MAY NEED SOME THIS AFTERNOON. BREEZY SOUTH WINDS WITH SOME GUSTS OVER 20KTS TODAY. ST/SC RETURNS AGAIN TONIGHT. 25 && .PREV EARLY MORNING DISCUSSION 341 AM... THE UNSETTLED WEATHER WILL CONTINUE INTO THE WEEKEND...WITH OCCASIONAL SHOWERS AND THUNDERSTORMS EXPECTED THROUGHOUT THE PERIOD. THE ONLY DRY TIME WILL BE WEDNESDAY WITH HEAVIER RAINS EXPECTED THURSDAY INTO FRIDAY. THE UPPER LOW NOW MOVING ACROSS WEST CENTRAL TEXAS WILL MOVE ACROSS THE SOUTHERN PART OF NORTH TEXAS TODAY. ALTHOUGH THE LOW IS FAIRLY WELL HANDLED BY THE 00Z MODELS...THE NORTHERN EXTENT OF THIS PRECIP SHIELD IS NOT HANDLED WELL. THAT CONCERN EXTENDS INTO THE REMAINDER OF THE DAY AND TONIGHT. WITH ANOTHER WEAK SHORT WAVE EXPECTED TONIGHT...WILL KEEP POPS IN THIS EVENING FOR THE REGION...ENDING THEM OVERNIGHT AS SUBSIDENCE SETS UP WEDNESDAY AHEAD OF THE NEXT STRONGER WAVE. CONVECTIVE ACTIVITY WILL INCREASE THURSDAY AND FRIDAY AS A STRONGER SYNOPTIC PATTERN DEVELOPS...WITH A COLD FRONT TO MOVE INTO THE REGION FRIDAY/SATURDAY. THE COOL SPELL WILL NOT LAST LONG AS RETURN FLOW BEGINS SUNDAY. DEWPOINTS WILL CONTINUE TO INCREASE UNTIL FROPA AS SOUTHERLY FLOW KEEPS GULF MOISTURE ON TAP. PWS WILL ALSO BE ON THE RISE...WITH SOME SIGNIFICANT RAINS POSSIBLE BY THE END OF THE WEEK. 42 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 80 68 84 69 / 40 40 10 10 WACO, TX 80 68 85 70 / 60 40 10 10 PARIS, TX 79 66 83 68 / 20 40 20 10 DENTON, TX 81 67 85 68 / 20 20 10 10 MCKINNEY, TX 80 67 84 68 / 20 40 10 10 DALLAS, TX 80 68 84 69 / 40 40 10 10 TERRELL, TX 80 67 84 68 / 40 40 20 10 CORSICANA, TX 80 68 84 69 / 60 40 20 10 TEMPLE, TX 81 69 85 70 / 60 40 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... TX...NONE. && $$ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FORT WORTH TX 1045 AM CDT TUE MAY 11 2004 .UPDATE... MAIN SHORT TERM FORECAST CONCERN WILL BE POPS. ANALYSIS OF 12Z KFWD RAOB DATA SHOWS STRONG INSTABILITY WITH CAPE VALUES EXCEEDING 2000 J/KG. ADDITIONAL ANALYSES SUGGEST THAT A PLUME OF DEEP MOISTURE IS ORIENTED FROM SOUTH-CENTRAL TEXAS...INTO WESTERN/CENTRAL OKLAHOMA... WITH A WEAK MID-LEVEL VORT MAX ALSO NOTED ACROSS WEST TEXAS. GIVEN THIS DATA...WE WILL NEED TO UPDATE TO INCREASE POPS TO THE CHANCE CATEGORY FOR ALL AREAS. SHORT TERM GUIDANCE FROM THE RUC/MESOETA IS IN DECENT AGREEMENT ON MOVEMENT OF SOUTH TEXAS MCS...LOCATED BETWEEN KUVA-KCOT-KHDO...TO THE EAST LATER THIS AFTERNOON. HOWEVER...ITS EFFECTS ON THE ANTICIPATED WEATHER ACROSS ACROSS NORTH TEXAS SHOULD BE NEGLIGIBLE...WITH DEEP MOISTURE ALREADY IN PLACE ACROSS THE AREA. CLOUD COVER/SFC WIND/MAX TEMP GRIDS ALL LOOK OKAY...AND WE WILL NOT CHANGE THEM AT THIS POINT. 65/DD .AVIATION... 700 AM CDT A FEW LLJ STORMS NEAR ACT AROUND DAYBREAK. MCS OVER HILL COUNTRY CONTINUES MAKING PROGRESS EASTWARD. MCV STILL BACK TOWARD NEAR SJT. AS FEATURE APPROACHES DEEPER MOISTURE...FURTHER DEVELOPMENT POSSIBLE THROUGH CENTRAL TEXAS. 06Z AVN QUITE AGGRESSIVE WITH QPF. HAVE CHOSEN TO FOREGO TSRA/SHRA AT METRO TAF SITES...BUT MAY NEED SOME THIS AFTERNOON. BREEZY SOUTH WINDS WITH SOME GUSTS OVER 20KTS TODAY. ST/SC RETURNS AGAIN TONIGHT. 25 && .PREV DISCUSSION... 341 AM CDT THE UNSETTLED WEATHER WILL CONTINUE INTO THE WEEKEND...WITH OCCASIONAL SHOWERS AND THUNDERSTORMS EXPECTED THROUGHOUT THE PERIOD. THE ONLY DRY TIME WILL BE WEDNESDAY WITH HEAVIER RAINS EXPECTED THURSDAY INTO FRIDAY. THE UPPER LOW NOW MOVING ACROSS WEST CENTRAL TEXAS WILL MOVE ACROSS THE SOUTHERN PART OF NORTH TEXAS TODAY. ALTHOUGH THE LOW IS FAIRLY WELL HANDLED BY THE 00Z MODELS...THE NORTHERN EXTENT OF THIS PRECIP SHIELD IS NOT HANDLED WELL. THAT CONCERN EXTENDS INTO THE REMAINDER OF THE DAY AND TONIGHT. WITH ANOTHER WEAK SHORT WAVE EXPECTED TONIGHT...WILL KEEP POPS IN THIS EVENING FOR THE REGION...ENDING THEM OVERNIGHT AS SUBSIDENCE SETS UP WEDNESDAY AHEAD OF THE NEXT STRONGER WAVE. CONVECTIVE ACTIVITY WILL INCREASE THURSDAY AND FRIDAY AS A STRONGER SYNOPTIC PATTERN DEVELOPS...WITH A COLD FRONT TO MOVE INTO THE REGION FRIDAY/SATURDAY. THE COOL SPELL WILL NOT LAST LONG AS RETURN FLOW BEGINS SUNDAY. DEWPOINTS WILL CONTINUE TO INCREASE UNTIL FROPA AS SOUTHERLY FLOW KEEPS GULF MOISTURE ON TAP. PWS WILL ALSO BE ON THE RISE...WITH SOME SIGNIFICANT RAINS POSSIBLE BY THE END OF THE WEEK. 42 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 80 68 84 69 / 40 40 10 10 WACO, TX 80 68 85 70 / 60 40 10 10 PARIS, TX 79 66 83 68 / 20 40 20 10 DENTON, TX 81 67 85 68 / 20 20 10 10 MCKINNEY, TX 80 67 84 68 / 20 40 10 10 DALLAS, TX 80 68 84 69 / 40 40 10 10 TERRELL, TX 80 67 84 68 / 40 40 20 10 CORSICANA, TX 80 68 84 69 / 60 40 20 10 TEMPLE, TX 81 69 85 70 / 60 40 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... TX...NONE. && $$ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 930 AM CDT TUE MAY 11 2004 .DISCUSSION...LARGE MCC JUST WEST OF COT IS MOVING DUE EAST THIS MORNING. LATEST RUC SHOWS RELATED SHORTWAVE TROUGH/VORT SHOULD BEGIN TO EJECT INTO NORTHEAST TEXAS THROUGH THIS AFTERNOON. THIS SHOULD KEEP THE MCC TO OUR NORTH BUT THE VERY SOUTHERN EDGE MAY CLIP THE NORTHERN CWA. WILL INCREASE NORTHERN POPS SLIGHTLY AND WILL INCREASE CLOUD COVER FOR THE DAY REGIONWIDE. && .MARINE...BOY020 REPORTED SOUTHEAST WINDS AT 10 TO 16 KNOTS WITH 5 FOOT SEAS. WILL HAVE A SMALL CRAFT SHOULD EXERCISE CAUTION FOR THE GULF WATERS TODAY DUE TO WINDS AND SEAS. WILL HAVE A SMALL CRAFT ADVISORY FOR THE LAGUNA LATER TODAY AS WINDS RIGHT ABOVE THE SURFACE ARE 30 KNOTS FROM THE SOUTHEAST. SOUTHEAST WINDS WILL CONTINUE FOR THE NEXT FEW DAYS AS HIGH PRESSURE OVER THE GULF COMBINES WITH LOW PRESSURE OVER THE GREAT PLAINS. WINDS WILL CONTINUE TO BE MODERATE FOR THE NEXT FEW DAYS AS LOW PRESSURE MOVES ACROSS THE GREAT PLAINS. && .AVIATION...VFR CIGS WILL DOMINATE THE REGIONAL AIRPORTS TODAY WITH MODERATE TO STRONG SOUTHEAST WINDS. CIGS WILL BE MVFR BY THIS EVENING AND CONTINUE THROUGH THE NIGHT WITH STRATOCUMULUS MOVING IN FROM THE GULF. VISIBILITIES WILL BE PREVAILING VFR THROUGH THE NEXT 24 HOURS. && .BRO WATCHES/WARNINGS/ADVISORIES...SCA GMZ130. && $$ 64/65 THIS PRODUCT IS ALSO AVAILABLE ON OUR INTERNET WEB PAGE AT: HTTP://WWW.SRH.NOAA.GOV/BRO tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 545 AM EDT WED MAY 12 2004 .DISCUSSION... MAIN FCST CONCERNS FOR SHORT TERM ARE SHRA/TSRA CHCS TODAY AND TONIGHT AND POTENTIAL FOR SVR STORMS. WATER VAPOR IMAGERY/RUC ANALYSIS CONTINUES TO SHOW A DEEP TROF OVER THE ROCKIES...A RIDGE OVER SE CONUS AND AN UPR LOW OVER NE CANADA. SFC LOW PRES TROUGH/COLD FRONT ASSOCIATED WITH ROCKIES TROF STRETCHES FROM WRN MN INTO TX PNHDL. CONVECTION ALONG MUCH OF EXTENT OF FRONT IN AREA OF 1000-2000 J/KG CAPE WHERE AXIS OF 50-55 KT 8H JET LOCATED AND IN RIGHT ENTRANCE OF 100+ KT 3H JET. EVEN OVER UPPER MI...SOME ISOLATED TSRA HAVE FORMED EARLY THIS MORNING AIDED BY CONVERGENCE AHEAD OF LOW LEVEL JET OVER THE PLAINS AND ELEVATED CAPES AROUND 500 J/KG PER ETA FCST SNDGS. WILL CONTINUE TO CARRY A MENTION OF ISOLD TSRA FOR ENTIRE CWA EARLY THIS MORNING WITH ELEVATED CAPE OF AROUND 500 J/KG PRESENT AND WAA CONTINUING AT 850 MB. MODELS SHOW BETTER CHC FOR CONVECTION TAKING PLACE IN LATER THIS AFTERNOON AND EVENING FOR WEST HALF OF UPR MI AND THEN OVERNIGHT FOR EAST HALF AS COLD FRONT MOVES IN FROM THE WEST. GFS A BIT SLOWER WITH TIMING OF FRONT THAN ETA AND GIVEN AMPLIFIED FLOW OVER THE CNTRL CONUS IS THE PREFERRED SOLN. INSTABILITY RISES THIS AFT AHEAD OF CDFNT WITH SBCAPES REACHING TO 1000-1500 K J/KG BY MID AFT IN WRN COUNTIES WITH BASICALLY NO CIN. DESPITE WB ZEROS AROUND 8500 KFT...DEEP LYR SHEAR FROM 20-30 KT WILL KEEP SVR THREAT ISOLD THIS AFTERNOON AND EVENING. WITH DWPNTS IN THE 50S ADVECTING OVER LAKE MI IN SSE FLOW WILL CONTINUE PATCHY FOG AND LOW CLDS FOR EAST AND CNTRL COUNTIES THIS MORNING. BUMPED UP POPS TO CATEGORICAL ACROSS THE CWA TONIGHT WITH FRONT SLOWLY CROSSING AREA AND GOOD UPR DIV PRESENT IN RRQ OF 100+ 3H JET MAX OVER WRN ONTARIO. WITH SLOWER GFS SOLN PREFERRED ON TIMING OF FRONT HAVE BUMPED UP POPS ON THU TO LIKELY OVER ERN COUNTIES AND HIGH CHC POPS IN CNTRL COUNTIES FOR SHRA/TSRA. WITH NEXT MOVG UP ALONG THE STALLED OUT FRONT FOR THU NIGHT/FRI WILL KEEP LIKELY POPS GOING FOR E HALF WITH CHC POPS TO WEST AND GFS SHOWALTER'S OF 0 TO -1C WARRANTS CHC OF THUNDER FOR ERN ZONES. GENERALLY FOLLOWED MORE REASONABLE GFS MOS GUIDANCE FOR TEMPS AS ETA MOVES COLD FRONT EAST TOO QUICKLY AND BRINGS IN MUCH COLDER TEMPS FOR LATER IN WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 950 AM EDT WED MAY 12 2004 .DISCUSSION... 10Z CAPE SOUNDING SHOWS PLENTIFUL LOW LVL MOISTURE BELOW 850 MB WITH A DRY LAYER FROM 850-650 MB. LOW LVL CONVERGENCE CLOUD LINES IN SE FLOW ALLOWING A FEW SHOWERS TO TO MOVE NW TWD THE COAST AND A FEW INTO THE INTERIOR. IN THE MID AND UPPER LVLS...WATER VAPOR IMAGERY AND RUC UPPER STREAMLINES/ VORTICITY FORECASTS UPR LVL TROUGH ACROSS THE ERN GULF WITH MID AND HIGH LEVEL MOISTURE ACROSS THE PENINSULA. ENOUGH MID LEVEL LIFT TO ALLOW FOR SOME LIGHT PRECIP RETURNS MOVING NE ON KMLB/KTBW 88D COMPOSITE REFLECTIVITY...THOUGH THIS PRECIP PROBABLY JUST FALLING FROM 12KFT-14KFT AS VIRGA. UPPER TROUGH AXIS POISED TO SLIDE SE AS HEIGHTS BEGIN TO BUILD ACROSS THE CENTRAL AND ERN GULF BY THIS EVENING. WILL MONITOR RADAR TRENDS AND MAY NEED TO ADD A LESS THAN 20 PCT POP FOR A FEW SHOWERS IN ESE FLOW. HIGH TEMP FORECASTS GENERALLY IN LINE BUT MAY TRIM A DEG OR TWO FROM SOME INTERIOR SPOTS. OTHERWISE LITTLE CHANGE TO MORNING FORECAST. && .MARINE...WINDS/SEAS CURRENTLY RUNNING 13-18KT/4-5FT WHICH IS RIGHT IN LINE WITH THE CWF. ISOLD MARINE SHRA WITH CELL OFFSHORE KXMR ACTUALLY SPITTING OUT SOME LTG IN SPITE OF THE FORMIDABLE WARM/DRY MID LEVELS. DON'T PLAN ON PUTTING TS INTO THE CWF AS MORE INTENSE ACTIVITY SHOULD WEAKEN BY AFTN. CWF WILL REMAIN ESSENTIALLY UNCHANGED. && .MLB WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...VOLKMER LONG TERM...CRISTALDI fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1015 AM MDT WED MAY 12 2004 .UPDATE...RELEASED A ZONE UPDATE TO BUMP WINDS UP INTO THE BREEZY TO WINDY CATEGORY THIS AFTERNOON SOUTH OF THE INTERSTATE. LOW PRESSURE WILL DEEPEN OVER SOUTHEAST COLORADO/WESTERN KANSAS THIS AFTERNOON. RUC INDICATES POSSIBILITY OF 30 KNOT SUSTAINED WINDS AROUND 00Z. GIVEN THE LATE TIMING OF THE INCREASE...EXPECT NOCTURNAL INVERSION TO KEEP THINGS BELOW WIND ADVISORY CRITERIA FOR ALL BUT A SHORT TIME THIS EVENING. WILL PROBABLY HANDLE THE EVENING WINDS WITH NOWCASTS RATHER THAN AN ADVISORY. MAIN CONCERN...HOWEVER...IS SEVERE WEATHER IN THE SOUTHERN COUNTIES. THE ENVIRONMENT WILL BE CHARACTERIZED BY VERY STRONG SHEAR AND VEERING WIND PROFILES FAVORABLE FOR SUPERCELL THUNDERSTORMS WITH LARGE HAIL. SEE THE SPC DAY 1 OUTLOOK FOR DETAILS. MAIN QUESTION WILL BE INSTABILITY...WHICH LOOKS TO BE MARGINAL...BUT INCREASING THROUGHOUT THE EVENING FROM GOVE TO TRIBUNE TO CHEYENNE WELLS. MADE NO CHANGES TO AFTERNOON TEMPERATURES...AS NEW GUIDANCE SUPPORTS THE PREVIOUS FORECAST. BURKE. .PREV DISCUSSION... 227 AM MDT WED MAY 12 2004 FORECAST CONCERNS ARE ON RECENT FRONTAL PASSAGES IMPACT ON TEMPERATURES TODAY AND THREAT FOR SEVERE WEATHER OVER WESTERN AND SOUTHERN PORTIONS OF THE AREA. TODAY/TONIGHT...FOCUS WILL BE ON THE POSITION OF THE COOL FRONT AND ITS AFFECTS ON SEVERE WEATHER POTENTIAL. CURRENT THINKING IS FOR SURFACE WINDS TO GRADUALLY VEER AROUND TO THE EAST OR NORTHEAST OVER MUCH OF THE AREA AS HIGH PRESSURE DESCENDS FROM CANADA. OVER MUCH OF EASTERN COLORADO SOUTHEAST THROUGH THOSE COUNTIES SOUTH OF THE INTERSTATE MOISTURE/INSTABILITY AND LIFT ALL COMBINE WITH AN EJECTING VORT MAX AND RIGHT REAR QUAD OF DEPARTING 250 JET TO CREATE A MODEST THREAT FOR SEVERE WEATHER. ALL THE INGREDIENTS ARE IN PLACE ITS NOW A MATTER OF LOOKING FOR SOMETHING TO SCREW IT UP. SPC HAS REALLY JUMPED ON BOARD IN THE DAY 1 OUTLOOK COMPARED TO YESTERDAYS DAY 2 OUTLOOK FOR THE SAME TIME PERIOD. WILL HAVE HIGHEST POPS ALONG THE BOUNDARY LATE IN THE DAY. POST FRONTAL LOW CLOUDINESS QUICKLY FILLS IN AS SURFACE WINDS BECOME NORTHERLY. DESPITE DECREASING LIFT AFTER 06Z AS UPPER DYNAMICS MOVE NORTHEAST OF US MODELS CONTINUE TO PAINT SOME PRETTY HIGH POPS. WILL KEEP THE CHANCE OF SHOWERS IN THE FORECAST AS VARIOUS WAVES AT 500 MB MOVE ACROSS FROM THE SOUTHWEST. THURSDAY/THURSDAY NIGHT...NORTH TO NORTHEAST WINDS AND BELOW NORMAL TEMPERATURES WILL BE OBSERVED AS HIGH PRESSURE SETTLES INTO THE AREA. MODELS HAVE BEEN CONSISTENT WITH AFTERNOON TEMPERATURES IN THE 50S SO CONFIDENCE IS MODEST. STILL HAVE SOME DYNAMICS WITH UPPER TROUGH AXIS OVERHEAD SO WILL KEEP A SLIGHT CHANCE OF SHOWERS IN THE FORECAST. FOR THURSDAY NIGHT SURFACE HIGH MOVES RIGHT OVER TOP OF US LEADING TO CLEARING SKIES AND RELATIVELY LIGHT WINDS. MOS AND 2M TEMPERATURES ARE IN THE BALLPARK WITH EACHOTHER SO WILL NOT STRAY FAR. FRIDAY/FRIDAY NIGHT...FLOW BECOMES A BIT MORE ZONAL ALOFT WITH SURFACE HIGH QUICKLY MOVING EAST. GFS/ETA 850 TEMPERATURES AS WELL AS MOS/2M TEMPERATURES ADVERTISING HIGHS BACK INTO THE MID 60S. SOUTHERLY WINDS RETURN FRIDAY NIGHT WITH MODERATING MIN TEMPERATURES. SATURDAY THROUGH WEDNESDAY...NO CHANGES MADE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ DDT ks AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1045 AM EST TUE MAY 11 2004 UPDATING THE FORECAST TO MAINLY REMOVE ANY MENTION OF MORNING/AFTERNOON WORDING. CURRENT FORECAST LOOKS TO BE RIGHT ON TRACK AND ONLY MADE MINOR SKY COVER CHANGES IN THE GRIDS. ISOLATED SHOWERS AND THUNDERSTORMS SHOULD BEGIN DEVELOPING DURING MAX DAYTIME HEATING. LATEST RUC AND MESOETA MODELS INDICATE A WEAK SHORTWAVE MOVING NORTH ALONG THE EASTERN CWFA IN THE AFTERNOON. THIS COULD HELP ENHANCE ANY BAY BREEZE ACTIVITY THAT DEVELOPS. OTHERWISE...ANY STORMS THAT FIRE WILL BE DRIVEN BY LEFT OVER MESOSCALE BOUNDARIES FROM YESTERDAY. LISTEMAA PREVIOUS DISCUSSION................................................. .SHORT TERM... SUMMER PTTN NXT 24 HRS...AS HIPRES RDG SFC-ALOFT REMAINS PARKED OFF CAROLINA COAST...PUMPING WARM..HUMID AIR ACRS CWFA. H8 TEMPS REMAIN NEAR 14-15C...SO SEE LTLCG TO MAXT FCST. DONT SEE MUCH FOR FORCING EITHER...WHICH MEANS THAT MESOSCALE BNDRYS WL INTERACT W/ OROGRAPHICS FOR WIDELY SCT LATE DAY-ELY EVNG CNVCTN. ATMOS CERTAINLY UNSTBL ENUF TO SUPPORT IT. MAY ALSO BE A TSRA SOMEWHERE NEAR THE BAY-RIVER BRZ BNDRY...BUT CVRG WL BE ISOLTD. WL TRIM POPS BACK TO THE MID TEENS-MID 20S...WHICH WL ROUND FOR A BLANKET 20 AREAWIDE AFTN-EVE. GRIDS WL DEPICT BTTR CHC IN THE MTNS. && .AVIATION...MVFR VSBY TIL SUNUP DUE TO HIGH RH. MAY BE SOME LCL IFR IN VLYS...SPCLY INVOF CHO DUE TO YDA PCPN. ANTICIPATE IMPVG VSBY AFTR 12-13Z. WIDELY SCT TSRA IN THE AFTN-EVE AREAWIDE. XPCT INITIATION TO OCCUR NEAR MTN RDGS...HAVING GREATEST IMPACT ON CHO AND MRB. && .MARINE...SLY FLOW LIKELY TO BECOME CHANNELED UPSTREAM...AND THEN TURN ONSHORE IN THE AFTN. && .HYDROLOGY...PWAT 1.25-1.50 INCHES. LC STORMS CUD BE HVY RAINERS. HWVR...DONT ANTICIPATE MUCH IN WAY OF PROBLEMS. && .LONG TERM... THURSDAY THROUGH NEXT WEEK... H5 RIDGE CONTINUES TO BLOCK IMPULSES FROM TRIGGERING MORE THAN ISOLATED CONVECTION OVER AREA THROUGH FRIDAY. ON SATURDAY HIGH MOVES EASTWARD AHEAD OF APPROACHING FRONT TRIGGERING MORE THUNDERSTORMS INCREASING CLOUDINESS OVER THE AREA. ETA SOLUTION IS FAVORED WITH DRIER REGIME AS FRONT APPROACHES. FRONT STALLS OVER AREA SUNDAY AND MONDAY INCREASING POPS THEN DRIFTS NORTH ON TUESDAY. DECIDED TO INCREASE POPS SLIGHTLY BUT OTHER THAN THAT NO MAJOR CHANGES MADE TO THIS MORNINGS PACKAGE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ HTS/DICARLO md AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TAUNTON MA 1145 AM EDT WED MAY 12 2004 .SHORT TERM... THIS AFTERNOON AND TONIGHT FORECASTS WERE UPDATED TO ACCOUNT FOR CURRENT CONDITIONS AND TO ADJUST MAX TEMPERATURES. WE ARE ALSO WATCHING CONVECTION DEVELOP ACROSS UPSTATE NY AND EASTERN PA WHERE THE AIRMASS IS MORE UNSTABLE... AND ALSO HAS SOME HELP FROM A WEAK SHORT WAVE AT 500 MB. RUC AND BOX ETA-10 SHOW THIS ACTIVITY SLOWLY SPREADING E INTO THE HUDSON VALLEY THIS AFTERNOON AS THE SHORT WAVE HEADS TOWARD CT. BOTH MODELS ALSO SUGGEST SOME CONVECTION COULD REACH OUR CT VALLEY ZONES TOWARD EVENING...AS THEY END UP ON THE EASTERN EDGE OF THE INSTABILITY AXIS AND GET SOME ADDED SUPPORT FROM THE SHORT WAVE. IT LOOKS LIKE MOST OF THE CONVECTION WILL BE FOCUSED ON WEAK BOUNDARIES OR TERRAIN FEATURES. LOCALLY HEAVY RAINFALL WOULD BE THE MAIN THREAT GIVEN HIGH PRECIPITABLE WATER VALUES AND WEAK WIND FIELDS ALOFT. .LONG TERM... THU THROUGH NEXT WED FORECAST THROUGH THE WEEKEND STILL LOOKS VALID. WE ARE IN THE WARM SECTOR SAT BEFORE THE COLD FRONT APPROACHES LATE IN THE DAY...SO WE ARE PLANNING TO LEAVE CHANCE POPS FOR SHOWERS AND THUNDERSTORMS LATE SAT INTO SAT NIGHT. FRONT PUSHES S OF NEW ENGLAND SUN ALLOWING FOR DRY AND COOLER WEATHER SUN AND MON. WE ARE LEANING TOWARD GFS ENSEMBLES AND HPC GUIDANCE FOR TUE AND WED. ANOTHER COLD FRONT WILL BE MOVING E FROM THE GREAT LAKES TUE... AGAIN PUTTING US IN THE WARM SECTOR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON. WE ARE GOING ABOVE MEX GUIDANCE AND SIDING CLOSER TO THE HIGH END OF THE ENSEMBLE MOS. DRY AND COOLER WEATHER IS EXPECTED WED AS THE FRONT PUSHES OFFSHORE. DESPITE 00Z GFS SHOWING MEASURABLE RAINFALL...ENSEMBLE MEAN SHOWS FRONT S OF NEW ENGLAND WITH A LOW PROBABILITY (BELOW CLIMO) OF 0.10" OF RAINFALL. && .AVIATION... VFR CONDITIONS EXPECTED TODAY...BUT A LOWERING TO MVFR TOWARD THURSDAY MORNING DUE TO SCATTERED RAIN SHOWERS UNDER LOWERING CEILINGS. && .MARINE... QUIET WITH WINDS AND SEAS FOR MOST OF FORECAST PERIOD. WINDS AND SEAS MAY INCREASE IN ADVANCE OF COLD FRONT SATURDAY AND SATURDAY NIGHT WITH SMALL CRAFT CONDITIONS POSSIBLE ESPECIALLY ALONG THE SOUTHERN OUTER WATERS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. $$ NEAR TERM...TLM SHORT TERM...STRAUSS LONG TERM...JWD ma AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1100 AM EDT WED MAY 12 2004 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST UPDATE IS THE THUNDERSTORM POTENTIAL FOR THIS AFTERNOON. WATER VAPOR IMAGERY AND RUC/ETA SHOWING A LONGWAVE TROUGH OVER THE THE NORTHERN HIGH PLAINS AND A RIDGE OVER THE UPPER GREAT LAKES. SURFACE ANALYSIS DEPICTS A DEEP LOW OVER NORTHERN MINNESOTA WITH A WARM FRONT STRETCHING EAST THROUGH NORTHERN LAKE SUPERIOR INTO SOUTHEAST ONTARIO...AND A COLD FRONT DRAPED SOUTHWEST INTO NORTHEAST KANSAS. THE COLD FRONT IS DIRECTING LOW LEVEL GULF MOISTURE INTO THE UPPER MISSISSIPPI RIVER VALLEY. SURFACE DEW POINTS OVER WISCONSIN AND MINNESOTA HAVE CLIMBED INTO THE MID 60S. OVERRUNNING OF THE WARM FRONT AND INSTABILITY ACCOMPANYING THE SHORTWAVE MOVING THROUGH THE UPPER LEVEL RIDGE ARE GENERATING SCATTERED SHOWERS AND THUNDERSTORMS OVER EAST CENTRAL AND NORTHEAST MINNESOTA. SCATTERED RAIN SHOWERS AND THUNDERSTORMS DEVELOPED THIS MORNING ALONG THE NORTHERN LAKE MICHIGAN SHORE IN ASSOCIATION WITH WEAK 850-500MB Q-VECTOR CONVERGENCE AND AREA OF THE HIGHEST CAPE VALUES. AS THE CAPE VALUES DIMINISH THE THUNDERSTORMS ENDED...HOWEVER A FEW SHOWER PERSIST. RUC/ETA SHOWING A LOW DEVELOPING WITHIN THE LONGWAVE TROUGH AND OVER SOUTHWEST SASKATCHEWAN THIS AFTERNOON. SHORTWAVE ENERGY SWINGING THROUGH THE TROUGH WILL REACH THE EASTERN DAKOTAS AND NORTHWEST MINNESOTA. LOW LEVEL MOISTURE WILL CONTINUE TO BE DIRECTED INTO THE UPPER GREAT LAKES REGION WITH THE HIGHEST RELATIVE HUMIDITIES OVER NORTHWEST WISCONSIN. RUC/ETA BOTH SHOW AN INCREASE IN Q-VECTOR CONVERGENCE OVER THE WESTERN U.P. AND BY 18Z MOST UNSTABLE CAPE WILL INCREASE TO >1000 J/KG OVER THE WEST END AND AROUND 800 J/KG OVER THE CENTRAL U.P. BY LATE AFTERNOON...THE CAPE VALUES AND Q-VECTORS WILL INCREASE CONSIDERABLY ACROSS THE FORECAST AREA. LIFTED INDICES AND CAPE POINT TO THE GREATEST POTENTIAL OF THUNDERSTORM DEVELOPMENT WILL BE OVER NORTH CENTRAL WISCONSIN THIS AFTERNOON WHERE MUCAPE ARE PROGGRED TO >2500J/KG AND LI'S < -4. HOWEVER...THAT COULD MEAN THAT THE STORMS WILL DEVELOP THERE AND MOVE INTO THE FORECAST AREA BE DISSIPATING. THIS WILL NEED CLOSE MONITORING THROUGH THE AFTERNOON. THE MID LEVEL RIDGE WILL SHIFT TO EASTERN ONTARIO THIS EVENING AS A WEAK SHORTWAVE SHIFT INTO THE WESTERN U.P. THE SURFACE LOW WILL SHIFT INTO WESTERN ONTARIO BY 00Z AND INTO NORTHERN ONTARIO OVERNIGHT...ALL THE WHILE DRAGGING THE COLD FRONT INTO CENTRAL U.P. THE MUCAPE VALUES WILL INCREASE TO >1000J/KG THIS EVENING. AS THE SURFACE HEATING DIMINISHES OVERNIGHT THE MUCAPE VALUES WILL SHIFT EAST AND DIMINISH AS WELL. WILL LEAVE THE OVERNIGHT FORECAST ALONE AND IT LOOKS REASONABLE AT THIS TIME. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE UPTON NY 1125 AM EDT WED MAY 12 2004 .DISCUSSION... .UPDATE...ONLY MINOR CHANGES TO CURRENT WEATHER FIELDS BASED ON CURRENT WEATHER AND TRENDS. WE UPPED TEMPS OVER LONG ISLAND AND HAVE ADDED STRATUS/FOG FOR WATERS TONIGHT. RIDGE REMAINS OVER REGION WITH DIFFUSE FRONTAL BOUNDARY OVER THE AREA. WATER VAPOR IMAGERY AND LATEST RUC MODEL RUN INDICATES A VERY WEAK SHORTWAVE OVER CENTRAL PA. CLOUDS ALSO IN THIS AREA CURRENTLY. MODELS INDICATE A FAIR AMOUNT OF SURFACE HEATING INSTABILITY WITH 2000+ J/KG OF SURFACE BASED CAPE AND -5 C ON THE LI. EXPECT MORE ACTIVITY THAN YESTERDAY WITH FOCUS OF CONVECTION BEING TO THE NORTHWEST OF NYC AND THEN A DRIFT TO THE EAST SOUTHEAST. HIGH PW AND SLOW MOVING CONVECTION INDICATES GOOD POTENTIAL FOR URBAN FLOODING. KEEPING POPS AS AND DO NOT ANTICIPATE THE FORMATION OF AN MCS AS WE HAD MONDAY NIGHT. && .AVIATION...EXPECT MVFR HAZE...THOUGH SURFACE OBS WILL LIKELY REACH P6SM WITH MIXING. HAZE ALOFT WILL CONTINUE. MODERATE AMOUNTS INSTABILITY ARE PRESENT IN THE ATMOSPHERE FOR WIDELY SCATTERED AFTERNOON/EARLY EVENING THUNDERSTORMS. EXPECT THESE TO ME FOCUSED TO THE NORTH AND WEST OF NYC. RIGHT NOW NOT EXPECTING A SIGNIFICANT IMPACT ON THE TERMINAL. ONLY HAVE TEMPO GROUP FOR SWF WITH VCNTY FOR LGA-EWR-TEB-HPN. EXPECT SEA BREEZE CONVERGENCE KEEPS ACTIVITY OUT OF JFK WITH A CLOSE CALL FOR EWR AND LGA...BUT MAINLY NORTHWEST OF THE TERMINAL. && ************* PREVIOUS 415 AM DISCUSSION ************************** SHORT TERM... THU AND THU NIGHT...AN EASTERLY FLOW BEGINS TO DEVELOP ON THU. MEANWHILE...THE UPPER LEVEL RIDGE REMAINS IN PLACE ALTHOUGH IT STARTS TO MOVE SLOWLY TO THE E TOWARD EVENING. FOR THU...I/LL KEEP THE POPS SIMILAR TO TODAY/S. HOWEVER...A TROF APPROACHES FROM THE SW THU NIGHT AS THE UPPER RIDGE MOVES A LITTLE TO THE E. I/LL INCR THE POPS FOR THU NIGHT...IN LINE WITH THE ETA AND GFS. FRI...I/LL FORECAST CHANCE POPS AS THE SW FLOW ALOFT CONTINUES. LONG TERM...NO SIG CHANGES...OTHER THAN TO ADD POPS FOR FRI NIGHT. && .MARINE...RELATIVELY QUIET THROUGH FRIDAY NIGHT. MAIN CHANGE TO PREVIOUS FORECAST FROM THU-FRI AS HIGH PRESSURE BUILDING SE INTO NEW ENGLAND TURNS WINDS EASTERLY THU AFTERNOON AND NIGHT...THEN SE-S ON FRI AS THE HIGH MOVES WELL E OF THE NEW ENGLAND COAST. SCA FOR ROUGH OCEAN SEAS POSSIBLE BEGINNING SAT MORNING WITH INCREASING SW FLOW AHEAD OF APPROACHING COLD FRONT. && .HYDROLOGY...SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE...BUT NO WIDESPREAD PROBLEMS EXPECTED FOR THE NEXT COUPLE OF DAYS. && ***************** END OF PREVIOUS FORECAST ************************ .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NJ...NONE. NY...NONE. MARINE...NONE. && $$ TONGUE ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 945 AM EDT WED MAY 12 2004 .DISCUSSION... RUC HAS A GGOD HANDLE ON OMEGA/PRECIPITATION BULLSEYE THIS MORNING. MODELS CONTINUE TO SHOW ACTIVITY ALONG THE SEABREEZE TODAY. WEAK INSTABILITY COUPLED WITH WEAK SHORT WAVE WILL BE ENOUGH FOR SHOWERS AND THUNDERSTORMS TODAY WITH PRECIPITABLE WATERS 1 TO 1 1/2". WILL TWEAK CURRENT FORECAST TO INCREASE POPS SLIGHTLY...MAINLY INLAND FROM THE BEACHES. REMAINDER OF THE FORECAST LOOKS TO BE ON TARGET FOR THIS AFTERNOON. && .MARINE... VERY QUITE OVER THE WATERS THIS MORNING WITH SOUTHERLY WINDS AROUND 8 KNOTS REPORTED AT 41013 WITH 3 FT SEAS. THE 06Z MESO-ETA SHOWING SOUTHERLY WINDS CONTINUING WITH SPEEDS REMAINING AROUND 10 KNOTS THROUGH THE DAY. GFS BUFR SOUNDING SHOWING WINDS ALONG THE COAST REACHING 11 KNOTS AT KILM AROUND 18Z. SO PLANS ARE ONLY TO MODIFY THE WIND SPEED TO AROUND 10 KNOTS FOR AFTERNOON FORECAST && .PRELIMINARY POINT TEMPS/POPS... WILMINGTON 83 64 83 65 / 20 20 10 10 FLORENCE 84 62 84 63 / 30 20 10 10 LUMBERTON 84 62 84 63 / 30 20 10 10 MYRTLE BEACH 80 65 79 66 / 20 20 10 10 && .ILM WATCHES/WARNINGS/ADVISORIES... NC...NONE. SC...NONE. && $$ PUBLIC: RJD MARINE: HAWKINS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1015 AM CDT WED MAY 12 2004 .UPDATE...ISOLATED LIGHT SHOWERS WERE LOCATED ALONG THE NORTHERN COASTAL BEND TO THE VICTORIA THIS MORNING BUT ONLY TRACE AMOUNTS ARE EXPECTED WITH THIS. 12Z KCRP SOUNDING IS SHOWING PWAT VALUES UP TO 1.58 INCHES WITH A SMALL CAP AROUND 800 HPA. THERE ARE GOOD LAPSE RATES ABOVE THIS CAP FROM 800-650 HPA BUT LACK OF DYNAMICS WILL LIKELY KEEP THIS INSTABILITY FROM BEING PUT TO USE. WITH THIS IN MIND...WILL CONTINUE TO KEEP ONLY MENTION OF ISOLATED ACTIVITY IN THE ZONES FOR THE INLAND LOCATIONS TODAY. TEMP FORECAST LOOKS ON TRACK WITH READINGS IN THE MID 90S ACROSS THE RIO GRANDE PLAINS AND MID 80S IN THE EAST. FORECAST FOR TONIGHT LOOKS INTERESTING HOWEVER. VORTICITY MAXIMUM SHOWING UP IN WV IMAGERY OVER THE BAJA IS NOT INITIALIZED WELL ON THE 6Z MODEL RUNS. RUC ANALYSIS IS SHOWING THIS SHORTWAVE BUT DOES NOT HAVE A HANDLE ON ITS MOTION. TIMING FOR THIS FEATURE TO MOVE ACROSS SOUTH TEXAS LOOKS TO BE BETWEEN MIDNIGHT AND 12Z. WITH MOISTURE IN PLACE AT THE SURFACE AND ONLY A WEAK CAP...THINK THAT POPS MAY NEED TO BE BUMPED UP TO AT LEAST 20 PERCENT TONIGHT ACROSS THE AREA...MAYBE TO LOW END CHANCE ACROSS THE NORTH. WILL MONITOR THE 12Z MODEL RUNS AS THEY COME IN TO SEE HOW THIS FEATURE IS HANDLED. SCEC CONDITIONS WILL CONTINUE OVER THE BAYS AND GULF WATERS TODAY...BUT WILL HAVE TO KEEP AN EYE ON THE OFFSHORE WATERS. THE SEAS HAVE CREPT UP TO 6 FEET AND WINDS ARE GETTING CLOSE TO SCA CONDITIONS. DO EXPECT SCA FLAG TONIGHT IN THE GULF BUT MAY HAVE TO UPDATE THE FORECAST TO FLAG THE WATERS A LITTLE SOONER THIS AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 86 75 85 72 84 / 05 10 30 30 60 VICTORIA 86 73 84 71 80 / 10 10 40 30 60 LAREDO 96 77 93 71 87 / 10 10 20 40 50 ALICE 91 74 89 72 85 / 10 10 30 30 60 ROCKPORT 83 76 83 74 82 / 05 20 40 30 60 COTULLA 93 74 92 70 80 / 10 20 20 40 50 && .CRP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 94/MJ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 955 AM PDT WED MAY 12 2004 .DISCUSSION... NORCAL REMAINS BETWEEN SYSTEMS THIS MORNING WITH UPPER TROUGH SLOWLY EXITING THE GREAT BASIN AND RIDGE BUILDING OVER THE EAST PACIFIC. TOUGH TO PICK OUT ANY SHORT WAVES EMBEDDED IN NORTHWEST FLOW ALOFT OVER OUR AREA...BUT BOTH THE GFS AND THE RUC SHOW A WEAK SHORT WAVE PASSAGE FOR THIS AFTERNOON. RESULTANT INSTABILITY APPEARS QUITE WEAK AND FOCUSED JUST SOUTH AND EAST OF OUR AREA...SO DRY FORECAST LOOKS GOOD FOR NOW. MORNING AIR RESOURCES BOARD LOW LEVEL SOUNDINGS SUPPORT SEVERAL DEGREES OF WARMING TODAY...SO GOING FORECAST IS IN GOOD SHAPE. NO UPDATES PLANNED. JJ && .STO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 342 PM CDT WED MAY 12 2004 .DISCUSSION... MAIN FORECAST CHALLENGES WILL BE RAIN CHANCES AND THE AMOUNT OF RAIN THROUGH THURSDAY NIGHT. LATEST SURFACE MAP AND RADAR HAD FRONTAL BOUNDARY FROM NEAR SENECA TO MANHATTAN TO ABILENE. FRONT HAS BEEN MOVING VERY SLOWLY AND MAY BE STARTING TO SLOW UP. SATELLITE SHOWING NEXT WAVE MOVING ACROSS COLORADO THIS AFTERNOON. FRONT FORECAST TO STALL ACROSS THE CWA THIS EVENING AS UPPER ENERGY EJECTS OUT TONIGHT INTO THE PLAINS WHICH CAUSES THE 850 MB WINDS TO BACK THIS EVENING. INCREASING LOW LEVEL JET TONIGHT OVER THE FRONT WILL PUMP UP HIGH PRECIPITAL WATER VALUES...IN EXCESS OF 150 PERCENT OF NORMAL. STRONG CONVERGENCE ALONG THE FRONT THIS AFTERNOON SHOULD BE ENOUGH TO DEVELOP SURFACE BASED CONVECTION ALONG THE FRONT AS CAP WEAKENS. LATEST RUC HAD CONVECTION FIRING ALONG THE FRONT FROM NORTHWEST OKLAHOMA INTO SOUTH CENTRAL KANSAS THIS EVENING NORTH INTO NORTHEAST KANSAS. HAVE ISSUED A FLOOD WATCH FOR TONIGHT THROUGH NOON THURSDAY FOR POINTS NORTH OF INTERSTATE 70. THIS AREA HAS RECEIVED ONE TO THREE INCHES OF RAIN OVER THE PAST FEW DAYS. CELLS MAY FOCUS IN NORTH CENTRAL KANSAS THEN MOVE NORTHEAST PARALLEL TO THE FRONT ACROSS NORTHEAST KANSAS. MCS GOOD BET TO DEVELOP LATER TONIGHT AND PROPAGATE ACROSS THE CWA THROUGH THURSDAY MORNING. WILL CONTINUE WITH HIGH POPS ON THURSDAY MORNING THEN DECREASE LATER IN THE AFTERNOON. FRONT IS FORECAST TO PUSH THROUGH THE CWA DURING THE AFTERNOON HOURS. TIGHT THERMAL GRADIENT BEHIND THE FRONT ON THURSDAY WILL MAKE HIGHS A CHALLENGE. CHANCES OF PRECIPITATION WILL CONTINUE THROUGH THURSDAY NIGHT WHEN UPPER TROUGH MOVES THROUGH. IN THE EXTENDED...GFS NOW HINTING AT A POSSIBLE MCS DEVELOPING SUNDAY NIGHT IN NORTH CENTRAL KANSAS THEN PROPAGATING EAST THROUGH THE MORNING ON MONDAY. KANSAS WILL BE ON THE SOUTH END OF THE WESTERLIES WITH SHORTWAVES MOVING THROUGH. A FRONT SETTLES DOWN INTO NORTHERN KANSAS BY TUESDAY...PROVIDING A FOCUS FOR NOCTURNAL CONVECTION. GRADUALLY WARMED TEMPERATURES THROUGH THE EXTENDED. && .TOP...WATCHES/WARNINGS/ADVISORIES...FLOOD WATCH FROM MIDNIGHT TONIGHT THROUGH NOON CDT THURSDAY...MAINLY NORTH OF AN ABILENE TO JUNCTION CITY TO HOLTON LINE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 230 PM EDT WED MAY 12 2004 CUMULUS DEVELOPED RAPIDLY EARLIER THIS AFTERNOON AS CONVECTIVE TEMPERATURES WERE REACHED. NO DISTURBANCES OR BOUNDARYS TO FOCUS CONVECTION ARE APPARENT...BUT EXPECT SCATTERED THUNDERSTORMS LATER THIS AFTERNOON JUST LIKE YESTERDAY. THE AXIS OF GREATEST INSTABILITY FORECASTED BY THE RUC THIS AFTERNOON HINTS THAT THE BEST CONCENTRATION OF CONVECTION WILL DEVELOP ALONG AND EAST OF INTERSTATE 65 AND ACROSS THE BLUEGRASS REGION. LESS CU DEVELOPMENT IN WESTERN KENTUCKY IS ASSOCIATED WITH WEAK SUBSIDENCE AHEAD OF A DISTURBANCE ALONG LOWER MISSISSIPPI VALLEY. CLOUDS WILL INCREASE TONIGHT AS CONVECTIVE DEBRIS CURRENTLY WIDESPREAD ALONG THE MISSISSIPPI RIVER WILL MOVE INTO CENTRAL KENTUCKY AFTER MIDNIGHT. A WEAK UPPER LEVEL TROUGH ASSOCIATED WITH CURRENT CONVECTION ACROSS ARKANSAS WILL MOVE NORTH ACROSS WESTERN PART OF STATE EARLY THURSDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AND BEGIN TO MOVE INTO WEST CENTRAL CWA WELL AFTER MIDNIGHT IN RESPONSE TO SUBTLE MID-LEVEL HEIGHT FALLS. WITH INCREASED CLOUD COVER AND SCATTERED CONVECTION...THURSDAY'S HIGHS WILL NOT BE AS WARM AS THIS AFTERNOON'S. WARM HUMID MODIFIED SUBTROPICAL AIR WILL REMAIN OVER THE ENTIRE REGION THROUGH LATE FRIDAY. BEST CHANCE OF WIDESPREAD PRECIPITATION WILL DEVELOP FRIDAY EVENING AND OVERNIGHT. A COLD FRONT ASSOCIATED WITH LOW PRESSURE ACROSS THE WESTERN GREAT LAKES WILL CROSS CWA OVERNIGHT FRIDAY. DRIER AND SLIGHTLY COOLER AIR WILL ARRIVE BEHIND FRONT DURING THE DAY SATURDAY. .IN THE EXTENDED (SATURDAY NIGHT THROUGH WEDNESDAY)... RIDGING WILL STILL EXTEND OVR THE EAST COAST SAT NITE WITH AN APPROACHING TROUGH...THE COLD FRONT WILL MOST LIKELY BE SOUTH AND EAST OF THE FORECAST AREA...BUT STALL OUT JUST SOUTH OF THE FORECAST AREA SUNDAY. A FEW DRY DAYS WILL FINALLY OCCUR SUN INTO MON AS THE UPPER FLOW FLATTENS OUT AND THE RIDGE REMAINS ACROSS THE SE STATES. THE FRONT WILL MOVE BACK NORTH MON AS A WARM FRONT...MOISTURE FROM THE GULF WILL OPEN UP WITH SLIGHTLY HIGHER THAN NORM TEMPS RETURNING. BOUNDARY WILL REMAIN NEAR THE FORECAST AREA TUES AND WED...WITH INSTABILITY AND THEREFORE THE POSSIBILITY OF TSTORMS BOTH DAYS. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. && $$ JSD/BS ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 510 PM EDT WED MAY 12 2004 .DISCUSSION... MAIN FCST CONCERNS ARE SVR TSRA POTENTIAL TONIGHT...WHETHER POPS ARE NEEDED THU AND TEMPS/POPS FRI. WATER VAPOR IMAGERY/RUC ANALYSIS SHOW TROF PERSISTING OVER THE ROCKIES WITH RIDGE OVER THE SE CONUS. ONE PROMINENT SHORTWAVE WAS LIFTING OUT OF TROF THRU ERN DAKOTAS/NW MN WHILE ANOTHER HAS JUST ROUNDED BASE OF TROF AND WAS LIFTING THRU COLARADO. SFC LOW PRES WAS LOCATED IN NE MN WITH TRAILING COLD FRONT JUST ENTERING WRN WI. LINE OF SHRA/TSRA HAS REDEVELOPED ALONG/AHEAD OF FRONT WITH OTHER STORMS DEVELOPING FARTHER E IN CAPLESS/UNSTABLE ENVIRONMENT (SBCAPE UPWARDS OF 2-2.5K J/KG OVER WRN UPPER MI). DEFINITELY A SUMMERLIKE FEEL THIS AFTN WITH MANY AREAS OVER THE W HALF OF UPPER MI WELL INTO THE 70S/MID 80S WITH DWPTS AROUND 60F. QUITE A DAY IN ONTONAGON AS TEMP HIT 84 AROUND 1730Z AND THEN DROPPED TO 43 AS WIND SHIFTED OFF THE LAKE. MODELS IN BETTER AGREEMENT ON PROGRESSION OF UPPER TROF AND SLOW MOVING SFC BOUNDARY THRU THE AREA OVER THE NEXT COUPLE OF DAYS. LOOKS LIKE THE FASTER COLD FRONT DEPICTED BY PREVIOUS ETA/NGM RUNS IS NOW THE PREFERRED SOLUTION FOR TONIGHT/THU. MODELS ALSO IN GOOD AGREEMENT NOW ON DECENT WAVE LIFTING ALONG FRONT TOWARD THE STRAITS ON FRI. CHILLY RAIN/N WIND FRI (HIGH TEMPS POSSIBLY AROUND 40 AT BEST KEWEENAW/NCNTRL NEAR LAKE SUPERIOR) WILL BE A STARK CONTRAST TO TODAYS SUMMERLIKE CONDITIONS. ETA IS JUST A TOUCH FASTER THAN GFS WITH MOVEMENT OF FRONT TONIGHT...AND WILL LARGELY FOLLOW ETA TIMING WITH ITS RECENT CONSISTENCY. FRONT SHOULD BE NEAR/JUST E OF KERY BY 12Z THU. AS FOR SVR TSRA THREAT...PLENTY OF SFC BASED INSTABILITY PRESENT ATTM (2-2.5K J/KG). HOWEVER...0-6KM SHEAR IS ONLY ON THE ORDER OF 20-30KT WHICH WILL WORK TO LIMIT SVR THREAT. NONETHELESS...POTENTIAL IS THERE FOR BRIEF ISOLD SVR STORMS (SVR HAIL/DAMAGING WIND) THIS EVENING BEFORE INSTABILITY DIMINISHES. WILL CONTINUE TO CARRY CATEGORICAL POPS E WITH FRONT AS THERE IS A BRIEF BOUT OF UPPER DIVERGENCE ASSOCIATED WITH JET STREAK LIFTING TO ONTARIO THAT SHOULD MAINTAIN SHRA/TSRA THRU THE NIGHT. IN THE WAKE OF FRONT...FAIRLY CONFIDENT NW/NCNTRL AREAS WILL BE DRY ON THU AS MIDLEVELS DRY AND SOME SFC RIDGING NOSES INTO THE AREA. SW/SCNTRL LESS CERTAIN AS NEXT WAVE DEVELOPS FARTHER S ALONG FRONT. HOWEVER...RIGHT ENTRANCE UPPER DIVERGENCE ASSOCIATED WITH DEVELOPING JET STREAK FROM CNTRL PLAINS TO WRN ONTARIO WILL NOT COME INTO PLAY UNTIL THU NIGHT. SO WILL TRY TO SLIP IN A DRY THERE. WILL LEAVE IN CHC POPS OVER THE E/SE THRU THE DAY DUE TO PROXIMITY OF FRONT. PREFER COOLER ETA MOS GIVEN MAGNITUDE OF COOLING BEHIND FRONT IN MN/ONTARIO (TEMPS ONLY IN THE 40S/30S) WHICH WILL BE SUSTAINED BY TRAJECTORY OVER LAKE SUPERIOR. ETA/GFS/NGM/CANADIAN MODELS ARE IN GOOD AGREEMENT ON SFC WAVE LIFTING TOWARD FAR ERN UPPER MI FRI. EXPECT A DECENT AREA OF AT LEAST LIGHT RAIN TO DEVELOP ON COOL SIDE OF WAVE THANKS TO HEALTHY UPPER DIVERGENCE UNDER RIGHT ENTRANCE REGION OF STRENGTHENING UPPER JET (120KT) FROM MN TO ONTARIO. TIMING ONSET IS STILL SOMEWHAT IN QUESTION...BUT WILL BRING IN LIKELY POPS AFTER MIDNIGHT THU NIGHT AND CARRY THRU FRI...WITH DIMINISHING TREND FRI AFTN FROM W AND SW. MOS NUMBERS ARE EXTREMELY VARIED FRI (UPWARDS OF 20 DEGREES) WITH NGM MOS AT WARM END AND ETA AT COOL END. PREFER COOLER ETA MOS GUIDANCE FOR BOTH THU NIGHT/FRI WITH N WIND AND EXPECTED RAIN. HIGH PRES STILL EXPECTED TO SETTLE OVER UPPER MI ON SAT. 850MB THERMAL TROF OVER THE AREA SHOULD RESULT IN SCT-BKN CU FOR A TIME INLAND FROM LAKE SUPERIOR BEFORE MIXING OUT. SUN THRU WED...ECMWF/UKMET/CANADIAN/GFS SHOW LESS AGREEMENT FOR THIS PERIOD THAN RUNS LOOKED AT YESTERDAY. 00Z GFS AND 12Z/11MAY ECMWF BOTH SHOWED A FAIRLY POTENT LOW PRES SYSTEM HEADING FROM THE SRN PLAINS TO GREAT LAKES MON/TUE. 06Z GFS/00Z ECMWF HAVE BACKED OFF DRAMATICALLY FROM THAT SOLUTION. THESE LATER SOLUTIONS LOOK MORE LIKE THE 00Z CANADIAN/UKMET RUNS WHICH SHOW MORE OF AN INVERTED TROF EXTENDING NE INTO THE WRN GREAT LAKES MON. WILL FAVOR THIS WEAKER SOLUTION OF AN INVERTED TROF OR JUST A WEAK LOW PRES CENTER MOVING ACROSS THE AREA MON. GOING FCST ALREADY HAS THIS COVERED WITH A CHANCE OF SHRA. PRIOR TO MON...WILL HOLD ONTO THE DRY FCST DURING THE DAY SUN WITH TROF SETTING UP W OF HERE. CONFIDENCE IS LOW THOUGH AS CANADIAN INDICATES SHRA SPREADING INTO WRN UPPER MI...AND ECMWF SUGGESTS THAT AS WELL. 12Z GFS EVEN INDICATING PCPN NOW. WILL GO WITH A DRY FCST BEHIND SYSTEM TUE/WED ALTHOUGH 00Z ECMWF SUGGESTS NEXT SHORTWAVE MAY ARRIVE AS EARLY AS WED. TEMPS THRU THE PERIOD SHOULD NOT STRAY TOO FAR FROM NORMALS. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 245 PM CDT WED MAY 12 2004 .SHORT-TERM (TONIGHT THROUGH THURSDAY NIGHT)...CLOUDS HAVE BEEN RELUCTANT TO BURN OFF TODAY ACROSS SOUTH TEXAS. THIS AND LIGHT SHOWERS REMAINING BELOW THE CAP HAS PRETTY MUCH KEPT TEMPS IN CHECK. WV IMAGERY SHOWING SHORTWAVE MOVING ACROSS NORTH-CENTRAL MEXICO AT THIS TIME. THIS FEATURE LOOKS LIKE ITS BEGINNING TO SHEAR OUT BUT MAY STILL PROVIDE SOME LIFT ACROSS THE REGION TONIGHT. BEST DYNAMICS FROM THIS FEATURE SHOULD ARRIVE BETWEEN MIDNIGHT AND 6 AM. RUC ANALYSIS IS ALSO SHOWING AN 80 KT JET CORE APPROACHING DEEP SOUTH TEXAS THIS EVENING...PUTTING OUR CWA IN THE LEFT FRONT QUADRANT. MODEL SOUNDINGS ARE SHOWING FAIRLY STEEP LAPSE RATES ABOUT 800 HPA THIS EVENING PRODUCING SOME ELEVATED CAPE. LLJ WILL ALSO CRANK UP TONIGHT WITH WINDS OF 40KT PROGGED AT 925 HPA. THIS WILL HELP INCREASE THE SHEAR ACROSS THE AREA AS WELL. WILL GO AHEAD AND KEEP 20 PERCENT RAIN CHANCES ACROSS THE NORTHERN TIER COUNTIES TONIGHT. EXPECT SCA CONDITIONS TO OCCUR THIS EVENING OVER THE OFFSHORE WATERS AS THE LLJ INCREASES. SHOULD DROP DOWN TO SCEC OVER THE BAYS. TOMORROW SHOULD BE SOMEWHAT QUIET LIKE TODAY...WITH DEPARTING SHORTWAVE LEAVING THE CWA IN A PERIOD OF SUBSIDENCE. WILL PUT LOW END CHANCE POPS ACROSS THE NORTHEAST TOMORROW TO ACCOUNT FOR THE POSSIBILITY OF SOME LIGHT/MODERATE SHOWERS AND THUNDERSTORMS. THE BEST SURFACE CONVERGENCE LOOKS TO BE TO THE EAST OF INTERSTATE 37. SLIGHT CHANCE POPS SHOULD SUFFICE ELSEWHERE. TEMPS TOMORROW SHOULD BE A FEW DEGREES WARMER THAN TODAY ACROSS MUCH OF THE AREA. WILL BLANKET 30 POPS ACROSS THE CWA THURSDAY NIGHT AHEAD OF THE NEXT UPPER-LEVEL SYSTEM AND ASSOCIATED SURFACE FRONT. THIS PERIOD WILL NEED TO BE WATCHED FOR FUTURE UPDATES AS THE TIMING BECOMES MORE CLEAR. && LONG-TERM (FRIDAY THROUGH WEDNESDAY)...RAIN CHANCES INCREASE THROUGH FRI AS THE MAIN TROF AXIS APPROACHES THE REGION AND A COLD FRONT SINKS SOUTHWARD INTO CENTRAL TX. AGREE WITH PREVIOUS SHIFT THAT...DEVELOPMENT OF AN MCS OVR N TX THU NIGHT ASSOC WITH THE COLD FRONT...WILL HELP PROPAGATE THE CF SOUTHWARD FASTER...OR AT LEAST OUTFLOW BOUNDARY/PSEUDO FRONT AFFECTING THE CWA BY FRI MORNING. MODELS INDICATE THE WIND SHIFT OR ACTUAL CF FRI NIGHT. LATEST MODEL SOLNS HAVE FRONT THRU THE CWA BY SAT MORNING THEN QUICKLY RETREATING N BY LATE SAT. THUS...WHERE THE CF ACTUALLY STALLS BEFORE RETREATING N IS UNCERTAIN...BUT FEEL IT WILL BE IN CLOSE PROXIMITY TO THE CWA. THIS WILL PROVIDE FOCUS FOR CONTD PRECIP AT LEAST FOR SAT MORNING BEFORE WINDS SHIFT BACK TO THE SE. ALSO OF NOTE...THE GFS SPLITS THE HEAVIEST PRECIP FRI EVENING...WITH PART OF IT MOVING MORE TOWARD E TX/LA IN RESPONSE TO THE UPPER LEV DYNAMICS SHIFTING NE AND THE OTHER PIECE MOVING SW TOWARD THE RIO GRAND AND MEX IN RESPONSE TO ANOTHER S/WV MOVG ACROSS MEX. DUE TO UNCERTAINTIES IN MODEL SOLNS...WILL LET LATER SHIFTS FINE TUNE POPS/LOCATION OF HEAVIEST RAINFALL FOR FRI AND SAT. RAIN CHCS TAPER OFF SUN/MON AS A RIDGE BLDS ACROSS THE REGION. MODELS INDICATE DISTURBANCES IN NW FLOW ALOFT SUN/MON WHICH...COMBINED WITH SFC FORCING/SEA BREEZE...WILL MAINTAIN A SLIGHT CHC OF PRECIP. WILL KEEP TUE/WED DRY WITH 5 TO 10 PERCENT POPS. && .TEMPERATURES AND WIND...THE COLD FRONT WILL BRING SLIGHTLY COOLER TEMPS FOR SAT MORNING. SE FLOW QUICKLY RETURNS LATE SAT WITH TEMPS REBOUNDING. ONSHORE FLOW RELAXES ON FRI AS THE COLD FRONT MOVES SOUTH ACRS TX. HOWEVER...WINDS COULD ACTUALLY INCREASE FRI DEPENDING ON DVLPMNT/STRENGTH OF MCS. WINDS EXPECTED TO SHIFT NE FRIDAY EVENING AND REMAIN BELOW SCEC THROUGH SAT DUE TO CF STALLING IN VCNTY OF CWA. ONSHORE FLOW QUICKLY RETURNS LATE SAT BUT IS EXPECTED TO REMAIN BELOW SCA CRITERIA THRU NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 76 85 74 84 69 / 10 20 30 60 50 VICTORIA 74 85 72 82 66 / 20 30 30 60 50 LAREDO 77 94 75 86 67 / 20 20 30 50 50 ALICE 75 90 73 85 67 / 10 20 30 60 50 ROCKPORT 76 84 74 81 70 / 20 30 30 60 50 COTULLA 73 91 72 84 65 / 20 20 30 50 40 && .CRP WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY FOR THE THE BAY WATERS. && $$ 94/MJ...SHORT-TERM 81/TE...LONG-TERM tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 305 PM CDT WED MAY 12 2004 .DISCUSSION...FORECAST FOCUS ON SEVERE WEATHER POTENTIAL INTO THIS EVENING...RAINFALL AND POSSIBLE HEAVY RAINFALL POTENTIAL THROUGH FRIDAY. STRONG SURFACE COLD FRONT...CURRENTLY PRODUCING CONVECTION FROM EASTERN MINNESOTA...PROGGED BY MODELS TO SLOWLY PROPAGATE EAST INTO WESTERN WISCONSIN BY 00Z THURSDAY. AHEAD OF THIS FEATURE...SUBTLE SURFACE CONFLUENT BOUNDARIES WERE COMBINING WITH AN APPROACHING VORTICITY MAXIMUM FROM NORTHEAST MISSOURI...TO PRODUCE SCATTERED THUNDERSTORMS EAST OF THE QUAD CITIES AREA. A FEW SHOWERS WERE FORMING ACROSS THE SOUTHWEST CWA...BUT WERE NOT HOLDING TOGETHER FOR TOO LONG. AS THE VORTICITY MAXIMUM APPROACHES...THE BETTER DEEP- LAYER SYNOPTIC LIFT FROM IT SHOULD BE ABLE TO HELP BETTER SUSTAIN ANY CELLS THAT FORM IN THE CWA INTO EARLY THIS EVENING. THE INSTABILITY IS HERE...WITH 100MB MIXED LAYER CAPES ESTIMATED TO BE 1000-1500 J/KG. RUC SOUNDINGS INDICATE THAT THE ATMOSPHERE IS MIXED OUT AND UNCAPPED...WHICH SHOULD HELP CONVECTIVE CELLS BECOME MORE NUMEROUS BY LATE AFTERNOON. HOWEVER...THE WIND SHEAR IS MARGINAL AT BEST...WITH 0-6 KM SHEAR VALUES OF 20-30KT. DOWNDRAFT CAPES OF 500-1000 J/KG COULD PRODUCE ISOLATED MARGINAL SEVERE WINDS...AND WET BULB ZERO VALUES AROUND 10KFT COULD BRING A MARGINAL SEVERE HAIL HAZARD. HOWEVER...AM NOT OPTIMISTIC THAT THE WEAK SHEAR WILL BE ABLE TO SUPPORT STORMS LONG ENOUGH TO PRODUCE ANYTHING MORE THAN SOME HEAVY RAINFALL. WILL STILL GO WITH CATEGORICAL POPS FOR TONIGHT...AS SURFACE COLD FRONT SLOWLY PROPAGATES INTO CWA...AND STALLS ACROSS THE CWA LATER TONIGHT. HEAVY RAINFALL BECOMES A CONCERN FOR TONIGHT AND AGAIN THURSDAY AFTERNOON THROUGH FRIDAY...AS STALLED SURFACE BOUNDARY COMBINES WITH PARALLEL SOUTHWEST STEERING FLOW ALOFT...AND FAIRLY HIGH PRECIPITABLE WATER VALUES OF AROUND 1.5 INCHES. ALSO...THE GFS MODEL...WHICH HAS HANDLED FEATURES WITH THIS SYSTEM THE BEST OVER THE PAST FEW DAYS...HAS A SURFACE LOW PROPAGATING ALONG THE BOUNDARY THURSDAY NIGHT AND FRIDAY. THIS SHOULD COMBINE WITH GOOD FRONTOGENETIC LIFT FROM A STRENGTHENING 850MB BAROCLINIC ZONE...WHICH WILL BE CROSSING THE CWA ON FRIDAY. LOOKING AT FORECAST SOUNDINGS FROM THE RUC AND GFS...MBE VELOCITIES INDICATE A SLOW BACKWARDS PROPAGATION OF ANY STORMS AND RAIN AREAS TONIGHT...AND AGAIN THURSDAY AFTERNOON THROUGH EARLY FRIDAY...A SIGN OF BACKBUILDING POTENTIAL. ALL IN ALL...WITH FLASH FLOOD GUIDANCE VALUES STILL IN THE 2-3 INCHES PER HOUR RANGE...AND AREA RIVERS STILL ABLE TO TAKE MORE RAINFALL BEFORE ANY WIDESPREAD FLOOD HAZARD DEVELOPS...WILL JUST MENTION HEAVY RAINFALL IN ZONES...AND WILL HOLD OFF ON ANY FLOOD OR HYDROLOGIC ADVISORIES FOR NOW. WILL STILL GO WITH LIKELY POPS THROUGH FRIDAY. SURFACE ANTICYCLONE FINALLY BUILDS INTO THE CWA FRIDAY NIGHT AND SATURDAY...BRINGING AN END TO THE RAIN. COLD AIR ADVECTION BRINGS COOLER TEMPERATURES FOR THE REST OF THE WEEKEND. && .MKX...NONE. $$ WOOD wi