FXUS64 KHGX 241120 AFDHGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 620 AM CDT FRI MAY 24 2013 .DISCUSSION... SEE THE 12Z AVIATION DISCUSSION BELOW. 40 && .AVIATION... A WEAK SURFACE BOUNDARY WILL LIKELY BECOME A SOURCE FOR THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON OVER THE NORTHERN COUNTIES. EXPECT THAT THE BEST THUNDERSTORM CHANCES WILL OCCUR OVER KCLL AND KUTS...AND TO A LESSER EXTENT AT KCXO AND KIAH. CHANCES GO DOWN TOWARD THE COAST. WITH SUNSET THIS EVENING THE CHANCES FOR MVFR CONDITIONS RETURN. FELT THAT IFR IS POSSIBLE BUT DECIDED TO WAIT FOR ANOTHER MODEL RUN OR TWO. ANY RAINFALL THAT MAY FALL WILL ALSO AFFECT THE AREA AS WELL. 40 && .PREV DISCUSSION... /ISSUED 356 AM CDT FRI MAY 24 2013/ DISCUSSION... AT 06Z...A WEAK FRONT EXTENDED FROM NORTHERN LOUISIANA...ALONG THE RED RIVER AND THEN UP TOWARDS THE TEXAS PANHANDLE. A LONG LIVED MCS WAS LOCATED OVER SOUTHWEST TEXAS AND MCV WAS FORMING SOUTHWEST OF KSJT. AT 850 MB...DEW POINTS WERE BETWEEN 12-14C AND A WEAK 850 MB TROUGH WAS LOCATED OVER SW TX AND A SECOND WEAKER TROUGH OVER WESTERN LOUISIANA. SEVERAL TROUGH AXES WERE NOTED AT 700 MB WITH ONE IN EASTERN NEW MEXICO...ANOTHER IN SW TX AND A THIRD ACROSS CENTRAL LOUISIANA EXTENDING INTO EASTERN TEXAS. AT 300 MB...WEAK UPPER LEVEL DIVERGENCE WAS NOTED OVER SOUTHWEST TEXAS WITH WEAK RIDGING OVER THE SOUTHERN PLAINS EXTENDING INTO EAST TEXAS. THE ABUNDANT MOISTURE AT 850 MB COUPLED WITH THE NUMEROUS 850/700 MB BOUNDARIES SHOULD BE ENOUGH TO GENERATE AT LEAST SCATTERED SHRA/TSRA LATER TODAY INTO TONIGHT. THE FCST SOUNDING FOR KCLL AT 21Z IS LOADED WITH PW VALUES SURGING TO 1.7 INCHES AND A K INDEX AT 42. CAPE VALUES APPROACH 3000 AND LI VALUES ARE -8. THESE PARAMETERS SUGGEST THAT A FEW OF THE STORMS COULD BE STRONG TO SEVERE OVER MAINLY THE NORTHWEST PORTION OF THE CWA. MOVEMENT WILL ALSO BE ON THE SLOW SIDE TODAY SO IF STORMS DEVELOP...SOME LOCALLY HEAVY RAIN WILL RESULT. THE HI-RES MODELS DID NOT PERFORM WELL YESTERDAY BUT SEEMED TO INITIALIZE A BIT BETTER TODAY AND BOTH THE NMM AND ARW SHOW DEVELOPMENT OVER THE NORTH THIS AFTERNOON SO RAISED POPS TO CHANCE. CLOSER TO THE COAST... ADDITIONAL CAPPING AND LOWER MOISTURE LEVELS WILL LIMIT RAIN CHANCES. MOISTURE LEVELS DROP ON SATURDAY BUT A WEAKNESS ALOFT UNDER CUTTING THE RIDGE AND DAYTIME HEATING WILL STILL PRODUCE A FEW SHOWERS OVER MAINLY THE NW HALF OF THE REGION. THE UPPER RIDGE AMPLIFIES A BIT SUNDAY AND MONDAY WITH WARMER TEMPS AND LITTLE OR NO RAIN. MEX NUMBERS AGAIN LOOK TOO COOL WITH THE UPPER RIDGE NEARBY...SO AGAIN WENT SEVERAL DEGREES WARMER THAN MEX GUIDANCE AND LEANED TOWARD THE WARMER ECMWF. LONG RANGE MODELS ARE DIFFERENT THIS MORNING AS THE UPPER RIDGE IS PROGGED TO SHIFT FURTHER EAST BY WEDNESDAY AS AN UPPER LEVEL TROUGH MOVES INTO ARIZONA. THE ECMWF IS DEEPER WITH THE TROUGH AND THIS SOLUTION IS SUPPORTED BY THE CANADIAN. THE GFS IS WEAKER AND FURTHER NORTH WITH THE TROUGH. LIFT SHOULD INCREASE AS THE TROUGH APPROACHES THU/FRI SO ADDED LOW POPS BACK TO THE FORECAST FOR NEXT THU/FRI. 43 MARINE... ONSHORE WINDS WILL LIKELY PERSIST THROUGH THE FORECAST PERIOD. EARLY NEXT WEEK THE COMPUTER MODELS INCREASE THE WIND SPEEDS TO AT LEAST CAUTION CRITERIA AND POSSIBLY ADVISORY LEVELS MONDAY NIGHT INTO TUESDAY NIGHT. 40 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 90 70 90 70 90 / 50 40 20 10 10 HOUSTON (IAH) 90 72 90 71 89 / 20 20 20 10 10 GALVESTON (GLS) 84 75 84 74 85 / 10 10 20 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43 AVIATION/MARINE...40