683 FXUS64 KHGX 100309 AFDHGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 1009 PM CDT THU APR 9 2015 .UPDATE... UPDATE FOR RAIN CHANCES. && .DISCUSSION... WILL RAISE POPS OVERNIGHT INTO FRI MORNING. LATEST HRRR IS MATCHING UP WELL WITH ADDITIONAL DEVELOPMENT ON THE APPROACHING COLD FRONT. THE FRONT COUPLED WITH A WEAK DISTURBANCE MOVING INTO THE STATE SHOULD YIELD HIGHER POPS THROUGH 15Z FRI. NEW ZONES OUT BY 1015 PM. 43 && .PREV DISCUSSION... /ISSUED 858 PM CDT THU APR 9 2015/ UPDATE... SEE EVENING UPDATE. DISCUSSION... AT 8 PM...A COLD FRONT EXTENDED FROM SPRINGFIELD MO TO PARIS TO SAN ANGELO. A PRE FRONTAL TROUGH EXTENDED FROM TEXARKANA TO WACO TO A WEAK AREA OF LOW PRESSURE WEST OF LAREDO. SHRA/TSRA DEVELOPED ALONG THE PRE FRONTAL TROUGH AND HAVE THUS FAR REMAINED JUST NORTH AND WEST OF THE HGX CWA. MODELS HAVE BEEN WAY TOO AGGRESSIVE WITH RAINFALL THIS EVENING AND HAVE LEANED TOWARD THE 18Z TEXAS TECH WRF SINCE IT INITIALIZED BEST. 00Z SOUNDINGS SHOW PW VALUES HAVE GONE UP TO 1.50 INCHES AND THE ATMOSPHERE IS LESS CAPPED THAN LAST EVENING. SOUNDINGS STILL SHOW SOME DRY AIR BETWEEN 850 AND 700 MB. THE COLD FRONT IS SURGING SOUTH AT A PRETTY GOOD CLIP OVER CENTRAL TEXAS WHILE THE EASTERN PART OF THE FRONT IS MOVING MORE SLUGGISHLY. THE DILEMMA FOR THE NIGHT IS FAR SOUTH THE FRONT MOVES AND ITS EFFECT ON TEMPERATURES AND RAIN CHANCES. THE TEXAS TECH WRF KEEPS THINGS RELATIVELY DRY OVERNIGHT AS THE CONVECTION PUSHES NORTHEAST AND AWAY FROM THE STATE. STILL FEEL THERE WILL BE SUFFICIENT LOW LEVEL CONVERGENCE ALONG THE BOUNDARY TO GENERATE A FEW SHOWERS/THUNDERSTORMS OVERNIGHT AND WILL LEAVE POPS AS THEY ARE. A S/WV ON WATER VAPOR WILL APPROACH SE TX FRIDAY MORNING AND FEEL SHRA/TSRA WILL INCREASE IN COVERAGE BY MID MORNING. MIN TEMPS ARE A TOUGH CALL AND WILL BE STRONGLY DEPENDENT ON THE FRONTAL POSITION. SINCE THE EASTERN PART OF THE FRONT IS MOVING SLOWER...FEEL THE FRONT WILL HAVE TROUBLE CLEARING THE CWA. CURRENT MIN TEMPS LOOK GOOD BASED ON WHERE THE FRONT IS EXPECTED TO BE AT 12Z FRIDAY. TWEAKED SKY GRIDS TO MATCH CURRENT OBS OTHERWISE WILL LEAVE CURRENT FCST AS IS. PREV DISCUSSION... /ISSUED 639 PM CDT THU APR 9 2015/ DISCUSSION... SEE THE 00Z AVIATION DISCUSSION BELOW. 40 AVIATION... A FRONTAL BOUNDARY WILL SINK INTO SE TX FROM THE NORTH TONIGHT. THE MODELS DIFFERED ON THE FRONTAL TIMING AND ON COVERAGE OF SHOWERS AND THUNDERSTORMS. DECIDED TO GO WITH A CONSENSUS OF THE RAP...NAM...AND GFS. WITH THIS IN MIND...THINK THAT MVFR IS FAIRLY CERTAIN TO DEVELOP OVER THE INLAND COUNTIES SOMETIME BETWEEN 03Z AND 09Z. MVFR CONDITIONS HAD ALREADY DEVELOPED OVER KLBX AND KGLS AT 23Z. THINK THAT WITH THE END OF DAYTIME HEATING...THE RAIN AND THUNDERSTORM COVERAGE WILL DECREASE AS THE FRONT REACHES INTO THE KCLL AND KUTS AREAS OVERNIGHT TONIGHT. HOWEVER...CHANCES OF RAIN WILL INCREASE OVER THE METRO HOUSTON SITES AND SOUTHWARD AFTER MID MORNING AND THROUGH MOST OF THE AFTERNOON ON FRIDAY. 40 PREV DISCUSSION... /ISSUED 336 PM CDT THU APR 9 2015/ DISCUSSION... SCT TSRA DEVELOPING N AND NW OF SE TX THIS AFT. BEGINNING TO SEE ISO TSTMS ACROSS FAR NORTHERN AREAS AS TEMPS REACH THE MID 80S. THE CF WILL APPROACH NW AREAS OF SE TX DURING THE LATE EVE HOURS AND WILL MOVE TO NEAR A CLL-DKR LINE AROUND OR A LITTLE AFTER MIDNIGHT. EXPECT SCT TSRA ALONG THE BOUNDARY LATE TONIGHT...WITH CONVECTION WEAKENING AS THE BOUNDARY SINKS SOUTH ACROSS SE TX DURING THE EARLY MORNING HOURS. THE SLIGHT SVR TSTM RISK GENERALLY NORTH OF A MADISONVILLE TO TRINITY LINE LOOKS APPROPRIATE FOR THIS AFT/TONIGHT. HAVE MADE SOME COOLER ADJUSTMENTS TO FRIDAY'S TEMPS AS THE FRONT WILL PROVIDE COOLING TO THE NORTHWEST HALF OF THE AREA. STILL A LITTLE UNCERTAIN HOW FAR SOUTH THE FRONT WILL MAKE IT ON FRIDAY BEFORE STALLING. THERE WILL BE AMPLE CLOUD COVER AREAWIDE WITH SHWRS/TSTMS IN THE VICINITY OF THE BOUNDARY...SO COOLER TEMPS ARE EXPECTED FOR ALL...WITH THE EXCEPTION OF POSSIBLY THE IMMEDIATE COAST. WILL TAPER POPS ON FRIDAY FROM THE SOUTHEAST THIRD (HIGHEST) TO THE NORTH. COULD BE AN ISO SVR THREAT FRIDAY NEAR AND SOUTH OF THE FRONT...BUT THIS THREAT IS CONDITIONAL ON INSTABILITY...WHICH COULD BE LACKING. IF THE INSTABILITY IS SUFFICIENT...COULD SEE A SVR WIND GUST THREAT WITH ANY ORGANIZED CONVECTION. SOUTHERLY WINDS WILL RETURN ON SATURDAY WITH SHWRS/TSTMS LIKELY ACROSS MOST OF SE TX WITH AN APPROACHING DISTURBANCE. MOISTURE LEVELS WILL CONTINUE TO INCREASE SUN/MON AS A STORM SYSTEM APPROACHES FROM THE WEST AND MOVES NORTH OF THE AREA. SE TX WILL LIKELY SEE A HEAVY RAINFALL THREAT LATE SUNDAY AND INTO MONDAY WITH WELL ABOVE NORMAL MOISTURE LEVELS AND UPPER LEVEL DIFFLUENCE PRESENT. CHC POPS CONTINUE NEXT WEEK AS A LARGE SCALE MID/UPPER TROF/CLOSED LOW DEVELOPS OVER THE CENTRAL PLAINS. THIS FEATURE WILL LIKELY ALLOW A STRONG COLD FRONT TO MOVE THROUGH SE TX NEXT THU. SHOULD HAVE A COOL AND BENIGN PD IN THE WAKE OF THIS FRONT/FEATURE. 33 MARINE... SOUTHERLY WINDS WILL DECREASE THIS EVENING...A CAUTION STATEMENT WILL CONTINUE THROUGH 8 PM. SEAS OF 2-4 FEET WILL CONTINUE THROUGH SUNDAY. SHOWER AND THUNDERSTORM CHANCES INCREASE ON FRIDAY AND CONTINUE INTO EARLY NEXT WEEK WITH AN UNSETTLED WEATHER PATTERN IN PLACE. 14/33 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 62 73 64 77 66 / 40 30 20 60 60 HOUSTON (IAH) 69 77 67 79 68 / 30 60 30 60 60 GALVESTON (GLS) 72 78 69 76 70 / 20 60 30 60 50 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43