946 FXUS64 KHGX 290115 AFDHGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 815 PM CDT WED MAR 28 2012 .DISCUSSION... UPDATED THE FORECAST A LITTLE EARLY THIS EVENING TO ACCOUNT FOR ONGOING ACTIVITY ACROSS OUT NORTHWEST COUNTIES IN ASSOCIATION WITH A SLOW MOVING DISTURBANCE SPINNING AROUND THE WACO AREA. A LITTLE CONCERNED THAT THE SHOWERS/THUNDERSTORMS IN AND AROUND THE CALDWELL AND COLLEGE STATION AREA COULD LINGER AROUND FOR A WHILE AND END UP PRODUCING SOME LOCALLY HEAVY RAINFALL THIS EVENING AND POSSIBLY INTO THE OVERNIGHT HOURS...SIMILAR TO WHAT HAPPENED EARLIER JUST NORTHWEST OF EDNA AND WHAT IS CURRENTLY HAPPENING A LITTLE FURTHER OFF TO THE WEST AND SOUTHWEST IN AND AROUND THE KENEDY AREA. WE WILL CLOSELY MONITOR THIS AS RADAR ESTIMATED RAINFALL TOTALS ARE ALREADY GETTING INTO A 1 TO 2 INCH RANGE. FOR THE UPDATE...KEPT POPS IN THE FORECAST FOR THE OVERNIGHT HOURS WITH THE HIGHER NUMBERS ACROSS OUR NORTHERN COUNTIES. ALSO RAISED POPS FOR TOMORROW ACROSS THE AREA BASED ON SOME OF THE LAST WRF MODEL DATA. NAM MOS HAS POPS ON THE HIGH SIDE FOR TOMORROW...AND IT DID A PRETTY DECENT JOB ON ITS POP FORECAST FOR TODAY. ALSO RAISED TONIGHT'S LOW TEMPERATURES JUST A BIT BASED ON CURRENT DEW POINTS. 42 && .PREV DISCUSSION... /ISSUED 703 PM CDT WED MAR 28 2012/ AVIATION... A WEAK MESOSCALE CYCLONIC VORTEX PASSING ACROSS EASTERN TEXAS...WITH POCKETS OF WESTERN AREA PRECIPITATION AFFECTING THE REGION THROUGH EARLY EVENING. VCSH THROUGH TONIGHT AS CANNOT RULE OUT A WEST-TO-EAST PASSING -SHRA. A MOISTENED AIR MASS...E-SE BREEZES FALLING TO UNDER 5 KNOTS...WILL SET THE STAGE FOR ANOTHER ROUND OF MVFR VSBYS WITHIN THICKER HAZE AND POSSIBLE ACCOMPANYING SHORT-LIVED IFR DECKS. UPPER RIDGING IS BREAKING DOWN AS WEAK TROUGHING (WITH A WESTERN DISTURBANCE OR TWO) INCREASES MID TO LATE AFTERNOON PRECIPITATION PROBABILITIES. MID TO LATE DAY ATMOSPHERE WILL BE UNSTABLE AND MOST ENOUGH...AS TEMPERATURES NEAR 80F...TO TRIGGER REGIONAL WIDELY SCATTERED SHOWERS. IF CONVECTION DOES COMMENCE...ISOLATED THUNDERSTORMS WILL LIKELY OCCUR BUT BEST TO EASE INTO THAT SCENARIO...OR WAIT AND SEE (ADMEND) WHEN THE SPATIAL/TEMPORAL COVERAGE IS BETTER DETERMINED. 31 PREV DISCUSSION... /ISSUED 334 PM CDT WED MAR 28 2012/ DISCUSSION... WIDELY SCT PCPN DEVELOPING OVER THE WESTERN PORTIONS OF THE CWA DO NOT SEEM TO BE MAKING MUCH PROGRESS PAST I-45 SO FAR THIS AFTN. SO THIS LOOKS TO BE THE LINE SEPARATING THE FA INTO "THE MORE 12Z CRP SOUNDING AIRMASS" FROM "THE MORE 12Z LCH SOUNDING AIRMASS". SHOULD SEE ALL THIS ACTIVITY DIE OFF AROUND SUNSET. ISO POPS ARE POSSIBLE TOMORRW AFTN BASED ON THIS CURRENT UPPER PATTERN OF SHORTWAVES AP- PROACHING FROM THE WSW BUT THE BEST POPS STILL LOOK TO BE TOMORROW NIGHT INTO FRI. PROGS FAIRLY CONSISTENT WITH THE PASSAGE OF A WELL DEFINED DISTURBANCE AT THAT TIME. DECENT DYNAMICS COMBINED WITH AN INCREASINGLY UNSTABLE/LESS CAPPED AIRMASS COULD PRODUCE DECENT TS/ SHRA COVERAGE. A BIT OF A BREAK OVER THE WEEKEND FROM THE MORE OR- GANIZED ACTIVITY BUT CANNOT TOTALLY RULE OUT ISO/WIDELY SCT MOSTLY DAYTIME PCN DURING THIS TIMEFRAME. ONE CHANGE OF NOTE FOR WITH THE EXTENDED WOULD BE THE TREND OF LEANING MORE TO THE ECMWF IN REGARD TO THE COLD FRONT ON MON. 12Z GFS RUNS NOW SHOWING A STRONG/FASTER FROPA WITH THIS SYSTEM BUT PREFER THE MORE STEADY ECMWF FOR TIMING ATTM. HAVE ALSO ADJUSTED TEMPS DOWN A FEW CATEGORIES FOR DAYS 6-8. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 63 80 64 80 63 / 50 30 40 40 20 HOUSTON (IAH) 63 81 63 81 64 / 30 30 40 40 20 GALVESTON (GLS) 68 78 69 78 68 / 20 30 40 40 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...42 AVIATION/MARINE...31