AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 1248 PM CDT WED MAY 11 2011 .DISCUSSION... CONCERNING THE 11/18Z TAF ISSUANCE. && .AVIATION... PRESSURE GRADIENT BETWEEN A HIGH OVER THE SOUTHEAST U.S. AND A LOW AROUND THE OKLAHOMA/TEXAS PANHANDLE WILL PRODUCE BREEZY SOUTHERLY WINDS WITH GUSTS NEAR 20 KNOTS THROUGH THE AFTERNOON. MVFR CEILINGS HOLDING ON AT KBPT AND EXPECT OCCASIONAL MVFR CEILINGS FOR THE REMAINDER OF THE AFTERNOON AT KBPT...WHILE OTHER SITES WILL SEE CLOUDS AT VFR LEVELS. SHOWER ACTIVITY ASSOCIATED WITH SHORT WAVE WEST OF HOUSTON IS EXPECTED TO STAY WEST OF THE FORECAST AREA WITH DECENT CAP HOLDING. WIND GUSTS WILL RELAX THIS EVENING WITH THE LOSS OF DAYTIME HEATING. MVFR CEILINGS WILL AGAIN DEVELOP AT ALL TAF SITES DURING THE EVENING HOURS AND HANG AROUND THROUGH THE MORNING HOURS. ANY SHOWER ACTIVITY ASSOCIATED WITH UPPER LEVEL DISTURBANCE IS EXPECTED TO STAY WEST OF TAF SITES THROUGH THIS FORECAST PERIOD. RUA && .PREV DISCUSSION... /ISSUED 1006 AM CDT WED MAY 11 2011/ UPDATE... ANOTHER WARM DAY WITH PARTLY CLOUDY SKIES ON SOUTHEAST WINDS. THIS PATTERN WILL HOLD THROUGH TOMORROW BEFORE THE UPPER LEVEL RIDGE FINALLY BREAKS DURING THE DAY ON THURSDAY. SHOWERS LATE TMRW AFTN OVER LAKES REGION OF SE TX WILL SPREAD INTO ALL OF SE TX BEFORE MIDNIGHT AND THEN INTO SW LA CURRENT ZONE PACKAGE LOOKS FINE. PREV DISCUSSION... /ISSUED 651 AM CDT WED MAY 11 2011/ 12Z TAF DISCUSSION... AVIATION... VFR CEILINGS EXPECTED TODAY AS MAIN TROUGH REMAINS OFF TO OUR WEST...WITH MVFR CEILINGS DEVELOPING THIS EVENING. SOUTHEAST WINDS TO INCREASE AND BE GUSTY LATE THIS MORNING INTO THE AFTERNOON BEFORE DIMINSHING SOMEWHAT TONIGHT. 05 PREV DISCUSSION... /ISSUED 609 AM CDT WED MAY 11 2011/ DISCUSSION... LATEST UPPER AIR ANALYSIS/WATER VAPOR IMAGERY SHOWED DEEP MEAN TROF ACROSS THE WRN CONUS...WITH DOWNSTREAM RIDGE ACROSS THE ERN CONUS. WITHIN THE BASE OF THE TROF...AN UPPER LOW WAS NOTED OVER THE FOUR CORNERS...WITH A LEAD SHORTWAVE IMPULSE EJECTING NORTHEAST THROUGH THE MO RIVER VALLEY. AT THE SFC...HIGH PRESSURE PREVAILS ACROSS THE SOUTHEAST CONUS...WITH SFC LOW OVER SE CO AND ATTENDANT LOW PRESSURE TROUGH OVER THE WESTERN HIGH PLAINS. WEATHER ACROSS THE REGION TODAY AND TONIGHT IS EXPECTED TO BE QUITE SIMILAR TO THAT OF THE PAST FEW DAYS...WARM WITH ABOVE NORMAL HIGH AND LOW TEMPERATURES...AND A BIT BREEZY INLAND DURING THE AFTERNOON HOURS...BUT OTHERWISE UNEVENTFUL. THAT WILL BEGIN TO CHANGE ON THURSDAY AS THE WESTERN CONUS TROF CONTINUES A SLOW BUT STEADY EASTWARD MARCH. THERE IS UNCERTAINTY REGARDING EXACT DETAILS OF CONVECTIVE EVOLUTION THURSDAY INTO FRIDAY...BUT THE REGIONAL/GLOBAL MODELS ARE IN GENERAL AGREEMENT WITH HOW THE SYNOPTIC PATTERN WILL SHAPE UP. AS THE MEAN TROF CONTINUES A SLOW EASTWARD TRACK...LEAD IMPULSES WILL BEGIN TO EJECT ACROSS THE REGION THURSDAY. THUNDERSTORMS ARE EXPECTED TO INITIATE MAINLY WEST OF THE REGION FROM SOUTH CENTRAL TX NORTHEAST INTO OK/AR...BUT FORECAST SOUNDINGS FARTHER EAST INDICATE THE NEAR OR COMPLETE EROSION OF CIN BY THE AFTERNOON...THUS ISOLD/SCTD ACTIVITY WILL BE POSSIBLE HERE IN ADDITION TO ANY ACTIVITY OUT WEST WHICH MAY PROPAGATE INTO THE AREA DURING THE EVENING HOURS. OUR GREATEST POTENTIAL FOR RAINFALL WILL COME LATE THURSDAY NIGHT INTO FRIDAY...AS PWAT IS PROGGED TO CLIMB NEAR OR ABOVE 150 PERCENT OF NORMAL CONCURRENT WITH THE APPROACH OF THE COLD FRONT AND THE UPPER LEVEL TROF PIVOTING THROUGH THE REGION...PLACING THE AREA IN A FAVORABLE POSITION RELATIVE TO THE UPPER JET. HOW FAVORABLE DEPENDS ON WHICH MODEL YOU LOOK AT...SO FOR QPF...TOOK A BLENDED APPROACH. FROM A SEVERE WEATHER PERSPECTIVE...PROGGED CAPE...WBZ HEIGHTS...AND SOMEWHAT ANEMIC LOW/MID LEVEL WINDS SUGGEST PRIMARILY A LARGE HAIL RISK...WITH DAMAGING WINDS ALSO POSSIBLE...AND TORNADOES LEAST LIKELY. WILL HOLD OFF ANY MENTION OF SEVERE IN THE GRIDS FOR NOW GIVEN THE OVERALL UNCERTAINTY AND CONTINUE TO MONITOR TRENDS. FRONT ITSELF IS PROGGED TO MOVE THROUGH THE AREA FRIDAY NIGHT...WITH DRIER AND COOLER AIR PERSISTING IN ITS WAKE THROUGH THE WEEKEND. MARINE... HIGH PRESSURE WILL REMAIN OVER THE NORTHEAST GULF OF MEXICO UNTIL FRIDAY...WHEN A COLD FRONT IS FORECAST TO SWEEP THROUGH THE REGION. MODEST ONSHORE FLOW WILL PREVAIL AHEAD OF THE FRONT...WITH OFFSHORE FLOW PREVAILING IN ITS WAKE. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE AHEAD OF AND IN ASSOCIATION WITH THE FRONT...ESPECIALLY FROM THURSDAY NIGHT THROUGH FRIDAY NIGHT. SOME OF THE THUNDERSTORMS COULD BE STRONG TO SEVERE. && .PRELIMINARY POINT TEMPS/POPS... KLCH 85 72 84 70 89 / 0 10 20 50 50 KBPT 85 72 84 71 89 / 10 10 30 40 40 KAEX 89 70 87 69 86 / 0 10 30 40 50 KLFT 86 72 86 71 87 / 0 10 20 50 50 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$