Flash Flood Warning 4, NWS Corpus Christi, TX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
710 AM CDT TUE MAY 6 2008

.UPDATE...WHILE DOING FIRE WEATHER FORECAST...DECIDED TO UPDATE
POPS A BIT BASED ON TRENDS AND 6Z GUIDANCE. ANOTHER ROUND OF
CONVECTION ASSOC W/ AREA OF UPR DIVERGENCE AHEAD OF JET STREAK
ACROSS NRN MEXICO HAS DEVELOPED WEST OF LRD. DECIDED TO LOWER POPS
TO 30 PERCENT SOUTH OF RKP TO ALI TO LRD LINE AS MOST ACTIVITY
SEEMS LINED UP TO GO ACROSS NRN COS. HAVE STRETCHED LIKELY 60
POPS ACROSS ALL NRN ZONES. NOTE THE TSTM THAT PASSED NORTH OF ALI
DISSIPATED RAPIDLY IN LAST HOUR. THIS MAY BE A SIGN THAT THE
STRONGER NEGATIVE THETA E ADVECTION AT H85 SHOWN IN THE GFS IS
CORRECT AND THIS MAY LIMIT HOW FAR EAST TSTMS WILL MAKE IT.
STILL...MID LEVEL STRATIFORM PRECIP MAY HOLD TOGETHER AND VERIFY
HIGHER POPS IN NERN ZONES. WILL ALSO HAVE TO WATCH AN OUTFLOW
BOUNDARY DROPPING SOUTH FROM STRONG CONVECTION IN NRN TEXAS LAST
NIGHT AS THIS COULD IMPACT THE FORECAST LATER TODAY OR TONIGHT IF
NEW CONVECTION FIRES ALONG IT. FOR NOW WILL CONTINUE TO SHOW
RAPID DROP OFF IN POPS AFTER 18Z.

ONE LAST NOTE...THE NAM12 IS ACTUALLY ATTEMPTING TO FORECAST SOME
SORT OF WAKE LOW DEVELOPING LATER THIS MORNING. HAVE NEVER SEE A
MODEL ACTUALLY ATTEMPT TO SHOW THIS...AND WILL HAVE TO WATCH
PRESSURE FIELDS CLOSELY AS IT COULD CAUSE BRIEF PERIOD OF VERY
GUSTY SE FLOW SIMILAR TO YESTERDAY.

&&

.AVIATION...CIGS ARE BOUNCING ALL OVER THE PLACE THIS
MORNING...BUT GENERALLY SEEING AREAS OF MVFR CONDITIONS ACROSS THE
REGION. CIGS WILL RAISE THIS AFTN TO VFR LEVELS...THEN MVFR
STRATUS IS LIKELY AGAIN THIS EVENING AND OVERNIGHT AS STRONG LLJ
PUMPS LOW LEVEL MOISTURE NORTH. SCT TSTMS COULD IMPACT AREA
AIRPORTS...ESP NORTH OF RKP TO LRD LINE THIS MORNING...THEN
CONVECTION WILL WIND DOWN RAPIDLY AROUND 18Z.

&&

.PREV DISCUSSION... /ISSUED 416 AM CDT TUE MAY 6 2008/

SHORT TERM (TODAY AND TONIGHT)...ANOTHER SMALL TSTM COMPLEX W/
AREA OF STRATIFORM RAIN EXTENDING NNE HAS MOVED OUT OF MEXICO INTO
WEBB COUNTY THIS MORNING. THESE STORMS ARE NOT NEAR AS ORGANIZED
AS THOSE YESTERDAY...BUT ARE STILL PUTTING DOWN 1 TO 2 INCHES OF
MUCH NEEDED RAIN. THEY HAVE BEEN HAMPERED BY AREA OF SFC
DIVERGENCE ACROSS THE WEST AND ARE SOMEWHAT MOVING OUT OF MORE
FAVORABLE H85 THETA-E RIDGING...BUT AREA OF UPR DIFFLUENCE AHEAD
OF THE NOSE OF AN H250 JET STREAK (SEEN ON MODELS AND RUC ANALYSIS)
WILL MAX OUT BETWEEN 12Z AND 18Z AND THIS IS EXPECTED TO HELP
KEEP THE TSTMS GOING. BASED ON THIS...EXTRAPOLATED 40-60 POPS
FAVORING NRN COS AHEAD OF THE TSTM CLUSTER THIS MORNING. ONCE THIS
CONVECTION DIES...RAIN CHCS WILL BE SLIM IN THE AFTN AND AM
SHOWING ONLY 10-20 POPS AFTER 18Z. ENERGY ASSOC W/ MAIN UPR TROUGH
WILL MOVE ACROSS NRN MEXICO INTO WRN TEXAS TONIGHT. MOST LARGE SCALE
LIFT WILL STAY NORTH OF THE REGION...BUT TAIL END OF A TSTM LINE
COMING OUT OF MEXICO COULD CLIP NWRN COS TONIGHT AND WILL FOLLOW
MAV POPS SHOWING 20-30% IN THIS AREA (HIGHEST NEAR COT). SPC
SLIGHT RISK AREA ALSO CLIPS THESE COS THROUGH 12Z WED. MAV TEMPS
GENERALLY LOOK GOOD AND DID NOT DEVIATE SIGNIFICANTLY FROM IT
GUIDANCE.

MARINE...LOW PRESSURE SYSTEM TRAVERSING THE SOUTHERN PLAINS WILL
LEAD TO INCREASING ONSHORE FLOW THIS AFTN AND TONIGHT. EXPECT SCA
CONDITIONS ALL AREAS...BEGINNING WITH SRN BAYS THIS AFTN AND
SPREADING INTO NRN BAYS...NEARSHORE AND OFFSHORE GULF WATERS THIS
EVENING AND OVERNIGHT. WINDS WILL SUBSIDE SLOWLY FROM WEST TO EAST
ON WED. HAVE ISSUED THE SCAS IN THIS MORNINGS PACKAGE.

LONG-TERM (WEDNESDAY THROUGH MONDAY)...A PACIFIC FRONT IS STILL
SCHEDULED TO PUSH INTO THE MID-SECTIONS OF THE CWA WEDNESDAY AS THE
MID/UPR LOW ENTERS THE SOUTHERN PLAINS. PRECIP CHANCES WILL
GENERALLY BE CONFINED TO THE VICTORIA CROSSROADS AHEAD OF THE FRONT
AS H85 FLOW BECOMES SWLY AND STRENGTHENS THE CAP OVER MOST OF SOUTH
TEXAS. THINK THE FRONT/DRYLINE WILL MAKE IT TO HIGHWAY 281 BY WED
AFTERNOON...BUT SLOWLY RETREAT WESTWARD DURING THE WEDNESDAY
EVENING/OVERNIGHT HOURS AS THE SEA BREEZE WORKS INLAND. NOT REAL
CONFIDENT IN ISSUING A FIRE WEATHER WATCH FOR THE WESTERN COUNTIES
WEDNESDAY GIVEN RECENT RAINFALL OVER THE AREA. IN ADDITION...THE
WINDS BEHIND THE FRONT ARE PROGGED TO ONLY BE AROUND 15 MPH DURING
THE AFTERNOON HOURS. A PROGRESSIVE ZONAL SYNOPTIC PATTERN WILL
DEVELOP OVER THE REGION BY THURSDAY AND PERSIST THROUGH THE REST OF
THE PERIOD. THE ONLY FEATURE OF INTEREST THURSDAY AND BEYOND IS A
COLD FRONT PROGGED BY BOTH THE GFS AND ECMWF TO ENTER SOUTH TEXAS
SUNDAY. THE ECMWF IS A LITTLE STRONGER WITH THIS FRONT THAN THE GFS.
HOWEVER...THE PARENT MID/UPR LOW IS PROGGED TO BE DISPLACED OVER THE
OHIO RIVER VALLEY...WHICH IS CONDUCIVE TO A WEAKER FROPA. FOR THE
TIME BEING...WILL KEEP THE FORECAST DRY FOR SUNDAY AND MONDAY AND
FOLLOW CLOSER TO THE GFS SOLUTION. OTHERWISE...TEMPERATURES WILL BE
ABOUT A CATEGORY ABOVE NORMAL THROUGH THE EXTENDED WITH TRIPLE DIGIT
READINGS EXPECTED ALONG THE RIO GRANDE EVERY DAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI    83  75  87  67  92  /  30  10  10  10   0
VICTORIA          81  71  86  64  94  /  60  10  30  10   0
LAREDO            93  75 100  70 105  /  30  20  10   0   0
ALICE             88  73  94  65  99  /  30  10  10  10   0
ROCKPORT          81  75  82  70  88  /  30  10  10  10   0
COTULLA           90  72  95  61 102  /  60  30  10   0   0
KINGSVILLE        88  73  93  66  97  /  30  10  10  10   0
NAVY CORPUS       82  76  84  71  88  /  30  10  10  10   0

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 7 PM CDT
     WEDNESDAY FOR THE FOLLOWING ZONES: WATERS BAFFIN BAY TO
     PORT ARANSAS 20 TO 60 NM...WATERS PORT ARANSAS TO MATAGORDA
     SHIP CHANNEL 20 TO 60 NM.

     SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM CDT
     WEDNESDAY FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM
     BAFFIN BAY TO PORT ARANSAS.

     SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT
     WEDNESDAY FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM
     PORT ARANSAS TO PORT OCONNOR.

     SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 4 PM CDT
     WEDNESDAY FOR THE FOLLOWING ZONES: COASTAL WATERS BAFFIN
     BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS PORT ARANSAS
     TO MATAGORDA SHIP CHANNEL OUT 20 NM.

&&

MJG...UPDATE/AVIATION

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
519 AM CDT TUE MAY 6 2008

GMZ230-235-250-255-270-275-TXZ229>234-239>247-071030-
BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS-
BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT OCONNOR-
COASTAL WATERS BAFFIN BAY TO PORT ARANSAS OUT 20 NM-
COASTAL WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM-
WATERS BAFFIN BAY TO PORT ARANSAS 20 TO 60 NM-
WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL 20 TO 60 NM-
LA SALLE-MCMULLEN-LIVE OAK-BEE-GOLIAD-VICTORIA-WEBB-DUVAL-
JIM WELLS-KLEBERG-NUECES-SAN PATRICIO-ARANSAS-REFUGIO-CALHOUN-
519 AM CDT TUE MAY 6 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH TEXAS AND THE MIDDLE
TEXAS COASTAL WATERS.

.DAY ONE...TODAY AND TONIGHT

AN UPPER DISTURBANCE WILL PRODUCE ISOLATED TO SCATTERED THUNDERSTORMS
ACROSS THE REGION THIS MORNING. AN ISOLATED STRONG THUNDERSTORM
PRODUCING VERY HEAVY RAINFALL...FREQUENT LIGHTNING...GUSTY WINDS
AND SMALL HAIL WILL BE POSSIBLE...ESPECIALLY ACROSS THE RIO
GRANDE PLAINS AND SOUTH TEXAS BRUSH COUNTRY THIS MORNING. ISOLATED
RAINFALL AMOUNTS OF 1 TO 2 INCHES WILL BE POSSIBLE IN STRONGER
STORMS.

A LINE OF STRONG TO SEVERE STORMS IS EXPECTED TO DEVELOP TONIGHT
ACROSS PORTIONS OF WESTERN AND CENTRAL AHEAD OF A VIGOROUS UPPER
LEVEL TROUGH. THE TAIL END OF THESE STORMS MAY CLIP PORTIONS OF
THE RIO GRANDE PLAINS NORTH OF A LAREDO TO TILDEN LINE LATE TONIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THERE IS A CHANCE OF THUNDERSTORMS ACROSS THE VICTORIA CROSSROADS
WEDNESDAY. HOWEVER...NO ORGANIZED SEVERE WEATHER IS EXPECTED AT THIS
TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

MJG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
458 AM CDT TUE MAY 6 2008

TXZ239-240-061100-
DUVAL-WEBB-
458 AM CDT TUE MAY 6 2008

...A STRONG THUNDERSTORM WAS AFFECTING DUVAL AND WEBB COUNTIES...

AT 453 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 20 MILES NORTH OF OILTON...MOVING EAST AT 20 MPH.

THIS STORM WILL BE NEAR...
  NEAR FREER BY 600 AM CDT.

DIME SIZE HAIL...AND WINDS 40 TO 50 MPH ARE EXPECTED WITH THIS
STORM. IN ADDITION...RAINFALL AMOUNTS OF 1 TO 2 INCHES CAN BE
EXPECTED IN AREAS AFFECTED BY THE CORE OF THE STORM.

MJG