000
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