FXUS64 KCRP 260510 AAB
AFDCRP
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
1110 PM CST FRI DEC 25 2009
.DISCUSSION...UPDATED FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...VFR CONDITIONS TO PREVAIL THROUGH APPROXIMATELY 15Z
SATURDAY MORNING. AFTER THIS TIME, A COASTAL TROUGH WILL BEGIN TO
DEVELOP BRINGING NORTHERLY SURFACE WINDS. A MOIST SOUTH FLOW
RIDING UP OVER THE SURFACE LAYER WILL LEAD TO OVERCAST SKIES WITH
IFR/MVFR CIGS AND ISOLD -SHRA. CONDITIONS WILL BEGIN TO IMPROVE
TOWARD THE END OF THE TAF PERIOD AS THE COASTAL TROUGH MOVES OFF
TO THE EAST.
&&
.PREV DISCUSSION... /ISSUED 903 PM CST FRI DEC 25 2009/
DISCUSSION...MAIN FORECAST CONCERN OVERNIGHT IS THAT OF FREEZING
TEMPERATURES. TO BEGIN, THERE ARE A COUPLE OF THINGS WORKING
TO KEEP THIS FROM HAPPENING. OBJECTIVE SURFACE ANALYSIS INDICATES
STRONG SURFACE HIGH PRESSURE CENTERED OVER THE UPPER TEXAS COAST
WITH RETURN FLOW BEGINNING TO SET UP ACROSS SOUTH TEXAS. LOCATIONS
AS FAR WEST AS LAREDO AND AS FAR NORTH AS SAN ANTONIO ARE SHOWING
SOUTHEAST WINDS. SLOWLY STRENGTHENING RETURN FLOW DUE TO THE
EASTWARD PROGRESSION OF THE SURFACE HIGH SHOULD HELP TO SLOWLY
BOOST SURFACE DEW POINTS OVERNIGHT. ALSO, CONSIDERABLE HIGH CLOUDS
CONTINUE TO STREAM IN FROM THE WEST-SOUTHWEST, WHICH SHOULD HELP
TO RETAIN A DEGREE OR TWO OF HEAT OVERNIGHT. WITH THE EXPECTATION
THAT TEMPS SHOULD BOTTOM OUT IN THE LOWER 30S IN THE FAVORED COLD
LOCATIONS, WILL ISSUE A SPECIAL STATEMENT ABOUT TEMPS CLOSE TO
FREEZING EARLY SATURDAY MORNING, BUT WILL OTHERWISE AVOID A FREEZE
WARNING. NO UPDATE NEEDED AT THIS TIME.
PREV DISCUSSION... /ISSUED 544 PM CST FRI DEC 25 2009/
DISCUSSION...NOTE AVIATION DISCUSSION BELOW.
AVIATION...EXPECT MVFR CEILINGS TO DEVELOP FROM SOUTH TO NORTH
ACROSS THE REGION AFTER 10Z SATURDAY. DRIZZLE MAY DEVELOP
GENERALLY EAST OF US 281 AFTER 16Z SATURDAY. EXPECT VFR CONDITIONS
TO DEVELOP FROM WEST TO EAST AFTER 18Z SATURDAY. GENERALLY LIGHT
EAST/NORTHEAST SFC WIND EXPECTED THROUGH SATURDAY.
PREV DISCUSSION... /ISSUED 318 PM CST FRI DEC 25 2009/
SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...SURFACE RIDGE IS
ANALYZED ACROSS THE COASTAL BEND THIS AFTERNOON AND WILL CONTINUE
TO MOVE EAST THROUGH THE LATE AFTERNOON AND EVENING...ALLOWING
FOR A WEAK ONSHORE FLOW TO TEMPORARY DEVELOP. A COASTAL TROUGH
WILL DEVELOP OFF THE LOWER TEXAS COAST ON SATURDAY AND LIFT
NORTHEAST SATURDAY NIGHT. ABOVE THE COOL AIRMASS NORTH OF THE
COASTAL TROUGH ISENTROPIC UPGLIDE WILL INCREASE EARLY SATURDAY
MORNING THROUGH SATURDAY AFTERNOON. (ALREADY EVIDENCE OF THIS
BEGINNING WELL SOUTH OF BRO). ASSISTING IN LIFT WILL BE WEAK PVA
ASSOCIATED WITH A DISTURBANCE LIFTING NORTHEAST THROUGH THE CWA
DURING THE FIRST HALF OF THE DAY AND FAVORABLE ENTRANCE REGION TO
UPPER LEVEL JET. THIS WILL RESULT IN CLOUDS...COOL TEMPERATURES
AND DRIZZLE WITH CHANCES FOR LIGHT RAIN ON SATURDAY. BEST CHANCE
WILL BE OVER THE COASTAL PLAINS AND VICTORIA CROSSROADS. AM
SLIGHTLY HESITANT WITH THE HIGH POPS GIVEN HOW QUICKLY MOISTURE
ADVECTION WILL HAVE TO TAKE PLACE TONIGHT AND SATURDAY MORNING
GIVEN THE VERY DRY AIRMASS CURRENTLY IN PLACE...AND THE POTENTIAL
FOR MAINLY DRIZZLE WITH TRACING OF PRECIPITATION. FOR NOW HAVE
WENT IN LINE WITH THE HIGHER GFS MOS POPS. HAVE UNDERCUT THE GFS
MOS TEMPS TONIGHT...ESPECIALLY ACROSS THE NORTH GIVEN THE LOW DEW
POINTS IN PLACE AND LEAST AMOUNT OF CLOUD COVER. THIS COULD RESULT
IN A BRIEF LIGHT FREEZE AGAIN ACROSS THE VICTORIA CROSSROADS
REGION. WILL ALLOW SWING SHIFT TO MONITOR TRENDS. UNDERCUT GFS MOS
HIGHS FOR SATURDAY ACROSS THE EAST GIVEN THE CLOUD COVER...DRIZZLE
AND LIGHT RAIN.
LONG TERM (SUNDAY THROUGH THURSDAY)...SURFACE HIGH PRESSURE BUILDS
IN FROM THE NORTH ON SUNDAY AND HELPS BRING AN END TO RAIN CHANCES.
CLOUDS AND CHANCES FOR RAIN INCREASE AGAIN ON MONDAY AS ISENTROPIC
UPGLIDE DEVELOPS OVER SOUTH TEXAS. WILL CONTINUE TO GO WELL BELOW
GUIDANCE ON TEMPERATURES AS CLOUD COVER AND SURFACE HIGH PRESSURE
REMAINS OVER THE AREA. MOISTURE CONTINUES TO INCREASE AS A COASTAL
TROUGH DEVELOPS OFF THE SOUTHERN TEXAS GULF COAST BY TUESDAY.
MEANWHILE...AN UPPER LEVEL TROUGH LIFTS NORTHEASTWARD INTO THE
CENTRAL UNITED STATES OUT OF SOUTHERN CALIFORNIA COAST. THIS WILL
HELP STRENGTHEN THE COASTAL TROUGH AND INCREASE RAIN
CHANCES...MAINLY OVER THE COASTAL COUNTIES AND VICTORIA CROSSROADS.
ALSO KEPT AFTERNOON TEMPERATURES IN THE 40S AND 50S TUESDAY WITH
CLOUD COVER AND AREAWIDE RAIN. THIS SYSTEM SHIFTS EASTWARD AND WILL
END RAIN CHANCES BY WEDNESDAY WITH HIGH PRESSURE BUILDING BACK IN.
BEYOND MIDWEEK MODELS CONTINUE TO DIFFER. THE ECMWF DRIVES A SHORT
WAVE TROUGH OUT OF THE ROCKIES SOUTHWARD LATE IN THE WEEK. THIS
WOULD BRING ANOTHER STRONG COLD FRONT DOWN INTO SOUTH TEXAS WITH
MUCH COLDER AIR. THE GFS IS LESS AGGRESSIVE WITH THIS FEATURE AND
KEEPS THE COLDER AIR TO THE NORTH. WILL CONTINUE TO TREND TOWARD A
COOLER SOLUTION AND GREATLY UNDERCUT GUIDANCE BY DAY 8.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 40 54 45 59 42 / 10 60 20 10 10
VICTORIA 31 52 40 58 35 / 0 50 30 10 10
LAREDO 42 59 41 61 42 / 0 10 10 10 10
ALICE 34 55 41 60 39 / 10 50 10 10 10
ROCKPORT 37 54 46 59 43 / 10 70 30 10 10
COTULLA 34 58 37 60 37 / 0 10 10 10 10
KINGSVILLE 38 56 43 61 41 / 10 60 10 10 10
NAVY CORPUS 44 58 48 59 45 / 10 70 20 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JAR/19...SHORT TERM/AVIATION
WC/87...LONG TERM
