Severe Thunderstorm Warning 145, NWS Houston/Galveston, TX

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
210 PM CDT SAT SEP 2 2000

OTHER THAN A PATCH OF BKN MID LEVEL CLOUDS OVER THE NWRN CWA...SUNNY
SKIES ACROSS SOUTHEAST TEXAS. THE MAIN FORECAST ISSUES ARE HEAT...
SEVERE DOWNBURSTS THIS AFTERNOON...SUN/MON AFTERNOONS...AND THEN
POPS/TEMPS IN THE EXTENDED RANGE.

IN THE VERY SHORT TERM GOES AND FSL MAPS SOUNDINGS SHOW PW OF 1.75
TO 2 INCHES...AND ELEVATED CAPE OF 2700-4000 J/KG. MID LEVEL WINDS
AND 0-6KM SHEAR ARE A BIT STRONGER THAN FRI. THE MID SHIFT ESTIMATED
A CONVECTIVE TEMP OF 102F...WHICH LOOKS PERFECT GIVEN THE MID LEVEL
CONVECTION THAT JUST STARTED BETWEEN TPL-ACT (WHERE TEMPS HIT 102F
THE PREVIOUS HOUR). THEREFORE...EXPECT CONVECTION TO START FROM CLL
THROUGH ONGOING MID LEVEL CLOUDS TO LFK BETWEEN 215 AND 330 PM. THERE
IS GOOD POTENTIAL FOR DOWNBURSTS BY LATE AFTERNOON GIVEN THE
INVERTED-V STRUCTURE BELOW 700 MB. AGREE WITH SPC DAY1 AND 2
OUTLOOKS FOR DOWNBURST POTENTIAL THIS AFTERNOON AND TOMORROW. THE
ETA OMEGA FIELDS AND MODEL SOUNDINGS INDICATE ANOTHER ROUND OF STORMS
MONDAY AFTERNOON.

OTHERWISE...THE 12Z NCEP MODELS ARE IN GOOD TO EXCELLENT AGREEMENT
WITH RETAINING THE HEAT AND LATE AFTERNOON DOWNBURST THREAT THROUGH
MON...THEN VERY LOW OR NIL POPS TUE/WED. THE MEDIUM RANGE MODELS
BRING THE SERN U.S. UPPER LOW ACROSS THE NRN GULF AND FOLLOWED BY
CYCLOGENESIS. HOWEVER...THE UPPER LOW HAS NOT MOVED MUCH FOR THE
PAST 5 DAYS...SO AGREE WITH HPC THAT IT'S NOT WORTH JUMPING ON UNTIL
IT ACTUALLY DOES MOVE. WILL GO WITH CURRENT FORECAST OF SLIGHT
CHANCE POPS THU-SAT.

THE MAV TEMPS LOOK THE BEST BY FAR OF ANY GUIDANCE...ALTHOUGH EVEN
THEY APPEAR TOO COOL...SO PLAN ON 1-3F ABOVE FOR BOTH MAXS AND MINS.
OBVIOUSLY...THE HEAT ADVISORY WILL CONTINUE...DAILY RECORD HIGHS
WILL BE BROKEN...AND THE MONTHLY/ALL-TIME RECORDS ARE THREATENED.
THE RED FLAG WARNING ALSO CONTINUES AS HOT AND DRY CONDITIONS NEAR
THE SFC WITH DOWNBURST WINDS CAN QUICKLY CAUSE A CONFLAGRATION.

.KHGX...HEAT ADVISORY ALL ZONES.
        RED FLAG WARNING ALL ZONES.

31/47/48

PRELIMS...
CLL GG 074/109 073/108 073 432
IAH GG 074/106 074/104 073 332
GLS UU 082/096 082/096 081 121

RECORDS...

    SUN       MON       SEPT      ALL-TIME
CLL 105/1951  102/1995  108/2000  110/1917
IAH 100/1995  100/1995  107/2000  107/1980 2000
GLS  98/1995   98/1995 +  98/1995  101/1932

GMZ335-TXZ163-164-176>179-195>200-210>214-226-227-235>238-031000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
320 PM CDT SAT SEP 2 2000

...SEVERE THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON AND EVENING AND
AGAIN ON SUNDAY...
...RED FLAG WARNING FOR VERY HIGH FIRE DANGER...
...RECORD SETTING DANGEROUS HEAT THROUGH AT LEAST LABOR DAY...

A STRONG AND PERSISTENT RIDGE OF HIGH PRESSURES THAT HAS BEEN
INFLUENCING THE WEATHER ACROSS TEXAS FOR THE LAST MONTH CONTINUES ITS
GRASP ON THE REGION. RECORD BREAKING TEMPERATURES ARE EXPECTED AGAIN
SUNDAY WITH THE MERCURY SOARING INTO THE 105 TO 110 DEGREE RANGE AT
INLAND LOCATIONS. HEAT INDICES WILL RANGE FROM 105 TO 115. NEAR THE
COAST MID 90S CAN BE EXPECTED AS THE SEABREEZE DEVELOPS AND MOVES
SLOWLY INLAND. ALTHOUGH THE TEMPERATURES MAY DROP WITH THE PASSAGE
OF THE SEABREEZE THE HUMIDITIES WILL RISE WHICH MAY INCREASE THE
HEAT INDICIES.

SCATTERED THUNDERSTORMS ARE CURRENTLY DEVELOPING DURING THE PEAK OF
AFTERNOON HEATING. DUE IN PART TO THE EXTREME HEAT...THESE WILL BE
UNUSUALLY HIGH BASED THUNDERSTORMS FOR SOUTHEAST TEXAS AND CAPABLE
OF PRODUCING STRONG DOWNBURST WINDS. THE THREAT FOR STRONG
DOWNBURSTS WILL CONTINUE INTO THE EARLY EVENING HOURS WHEN
TEMPERATURES COOL SOMEWHAT. SIMILAR CONDITIONS WILL BE PRESENT
SUNDAY AFTERNOON FOR MORE DOWNBURST PRODUCING THUNDERSTORMS.

IN ADDITION...THE DROUGHT THAT SOUTHEAST TEXAS HAS BEEN EXPERIENCING
HAS DRIED LEAVES AND TREE LITTER THAT HAVE MADE VERY FLAMMABLE FUEL
MATERIAL FOR EASILY STARTED FIRES. BURN BANS ARE IN EFFECT FOR ALL
OF SOUTHEAST TEXAS. THE LIGHTNING FROM THUNDERSTORMS WILL BE CAPABLE
OF STARTING WILDFIRES EASILY...AND THE STRONG WINDS ASSOCIATED WITH
THE STORMS WILL FAN THE FLAMES. BECAUSE OF THIS THREAT...A RED FLAG
WARNING IS IN EFFECT. PERSONS ACROSS SOUTHEAST TEXAS SHOULD BE ON
THE LOOKOUT FOR FIRES THROUGH THE HOLIDAY WEEKEND AND CURTAIL
ACTIVITIES THAT COULD START FIRES ESPECIALLY WHILE OPERATING
EQUIPMENT CAPABLE OF IGNITING FIRES AND WHILE COOKING OUT.

FURTHER INFORMATION ON THE FIRE WEATHER THREAT CAN BE FOUND ON THE
INTERNET AT

HTTP:\TXFORESTSERVICE.TAMU.EDU

OR BY PHONE TOLL FREE AT 1-877-258-5973.