Severe Thunderstorm Warning 112, NWS Houston/Galveston, TX

SOUTHEAST TEXAS FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1025 PM CDT SAT OCT 19 2002

UPDATE FOR CWF...WILL DROP TO SCEC FOR 0-60 NM AND MAKE MINOR
CHANGES TO WINDS FIRST TWO PERIODS.

COOLING CLOUD TOPS AND INCREASING LIGHTNING ACTIVITY NOTED WITH
CONVECTION OVER SWRN ZONES...WITH ECHOES BEGINNING TO TRAIN THIS
AREA. JUST ISSUED FFS FOR WHARTON/JACKSON COUNTIES WHERE AROUND 3
INCHES OF RAIN HAS FALLEN IN THE LAST 2-3 HOURS. 00Z ANALYSIS SHOWS
120 KNOT JET STREAK OVER CENTRAL TX WITH OUTFLOW BOUNDARY FROM
EARLIER TODAY HAVING SHIFTED OFF THE UPPER TX COAST. LOOKS LIKE
BOUNDARY IS BEGINNING TO WASH OUT WITH CONVECTION OFFSHORE LIFTING
NORTHWARD NOW. NEITHER 18Z AVN OR ETA HANDLED JET STRUCTURE OR
ONGOING CONVECTION VERY WELL. EXPECT THREAT FOR HEAVY RAINFALL
OVERNIGHT WITH TRAINING ECHOES/CELL MERGERS MAINLY OVER COASTAL
ZONES. WILL KEEP WITH GOING POPS IN FCST AND ADD MENTION OF HEAVY
RAINFALL TO CENTRAL/SRN ZONES. COLD FRONT SURGING THROUGH NORTH TX
EXPECTED TO SLOW DRAMATICALLY AS IT APPROACHES CWA. ONLY MINOR
TWEAKS TO REST OF FCST ANTICIPATED.

35/43

.HGX...SCEC 0-60NM

PRELIMS...
CLL EE 064/076 063/076 065 533
IAH CE 065/077 065/079 068 533
GLS CE 070/080 073/075 075 633

PREVIOUS DISCUSSION...
WIDESPREAD SHOWERS OVER THE REGION RACING OFF TO THE NORTHEAST ABOVE
THE SHALLOW COOL POOL THAT PUSHED THROUGH THE AREA AND IS NOW NEAR A
PSX TO 15S OF HIGH ISLAND LINE. RR JET ENTRANCE REGION OVERHEAD AND
LIFTING OUT TO THE ENE AS THE UPPER LOW OVER LBB GETS SHEARED OUT IN
THE CONVERGING FLOW TO ITS EAST. THE JET LOSES A GREAT DEAL OF
CURVATURE AND HENCE HAS VERY WEAK LIFT OVER THE REGION BY 06Z. COLD
FRONT STILL UP NORTH FROM NEAR SPS TO LIT. PREFRONTAL TROUGH/OUTFLOW
TRAILS OFF FROM NEAR MLU-AEX-BPT-BUOY035-PSX. EXPECT THAT THIS
OUTFLOW BOUNDARY SHOULD GRADUALLY MODIFY/MIX OUT OVER NIGHT YIELDING
LIGHT E-S WINDS OVER THE FA. WILL PROBABLY GET OFF AND ON SHOWERS
THROUGHOUT THE NIGHT BUT WITH A GRADUAL DECREASE IN COVERAGE. MORE
SOUTHERLY WINDS SHOULD BE IN PLACE SUNDAY AND EXPECT THE COLD FRONT
TO BE CONFINED TO N TX OR PERHAPS MAKE IT AS FAR SOUTH AT CROCKETT
SUNDAY. CLOUDY NIGHT SHOULD GRADUALLY GIVE WAY DURING THE AFTERNOON
SUNDAY TO MOSTLY CLOUDY. COULD GET SOME WIDESPREAD FOG TONIGHT AFTER
TEMPERATURES DROP BACK DOWN TO 64 TO 65 DEGREES AND WINDS GO CALM.
FOG WILL LIKELY BE AN ISSUE AGAIN SUNDAY NIGHT.

AS FOR THE REMAINDER OF THE PACKAGE WILL INCREASE CLOUD COVER ON
MONDAY TO MOSTLY CLOUDY AND MAINTAIN THE MOSTLY CLOUDY WITH SLIGHT
CHANCE TO CHANCE FOR THE REMAINDER OF THE WEEK. DO NOT HAVE MUCH
CONFIDENCE IN 12Z GFS SOLUTION OR FOR THAT MATTER THE 00Z. THE
PREVIOUS MRF AND THE UKMET/ECMWF MATCH UP BETTER. THESE WOULD FAVOR
THE MOIST SW FLOW ALOFT WITH A SERIES OF S/W RIDING OVERHEAD. SO A
ITS A LOW CONFIDENCE FORECAST...AND GIVEN THE CURRENT PACKAGE
IS ALREADY STRADDLING THESE SOLUTIONS WILL MAKE LITTLE CHANGE.

ON THE MARINE SIDE WILL CARRY AN SCA 20-60NM AND SCEC FOR 0-20NM
BASED ON SEAS.

HAVE SET A NEW RAINFALL RECORD AT CLL.

45/41

GMZ300-330-335-350-355-370-375-TXZ163-164-176>179-195>200-210>214-226-
227-235>238-201200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
533 AM CDT SAT OCT 19 2002

...LOCALLY HEAVY RAINFALL POSSIBLE TODAY ACROSS THE NORTHERN AND
CENTRAL PORTIONS OF SOUTHEAST TEXAS...

.DAY ONE...
TODAY...SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE NORTHERN
PORTIONS OF SOUTHEAST TEXAS ALONG A LINE FROM CALDWELL TO
MADISONVILLE TO CROCKETT BEFORE SUNRISE THIS MORNING. AVERAGE
RAINFALL AMOUNTS OF 1 INCH ARE EXPECTED WITH ISOLATED TOTALS OF 2 TO
3 INCHES POSSIBLE. ACTIVITY WILL SPREAD INTO THE REMAINDER OF
SOUTHEAST TEXAS THROUGHOUT THE DAY. SIMILAR RAINFALL AMOUNTS ARE
ANTICIPATED FOR INLAND COUNTIES WHILE AMOUNTS ALONG COASTAL COUNTIES
WILL AVERAGE 1/2 TO 1 INCH WITH ISOLATED 2 INCH TOTALS POSSIBLE.
WIND GUSTS BETWEEN 30 AND 40 MPH MAY ACCOMPANY THE STRONGER
THUNDERSTORMS AS THEY MOVE ACROSS THE AREA.

.SPOTTER CALL TO ACTION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUIRED TODAY IF RAINFALL AMOUNTS BECOME
GREATER THAN ANTICIPATED.

.DAYS TWO THROUGH SEVEN...
SUNDAY THROUGH FRIDAY...SHOWERS AND THUNDERSTORMS WILL BECOME
SCATTERED ON SUNDAY AND MORE ISOLATED ON MONDAY AND TUESDAY AS A
SLOW MOVING COLD FRONT LINGERS ALONG OR NEAR THE COAST. RAINS ARE
EXPECTED TO INCREASE WEDNESDAY THROUGH FRIDAY AS UPPER LEVEL
DISTURBANCES MOVE ACROSS THE STATE IN A MID AND UPPER LEVEL WEST TO
SOUTHWEST FLOW. NO SEVERE WEATHER IS EXPECTED THROUGH THE PERIOD.