Flash Flood Warning 82, NWS Houston/Galveston, TX

000 
WGUS74 KHGX 220132
FFSHGX
TXC089-220140-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
730 PM CST SUN NOV 21 2004

...THE FLASH FLOOD WARNING FOR COLORADO COUNTY IS CANCELED...

A FLOOD WATCH REMAINS IN EFFECT.

THE STORMS THAT BROUGHT HEAVY RAINS TO CENTRAL COLORADO COUNTY 
EARLIER THIS EVENING HAVE MOVED OUT OF THE AREA.

PLEASE REPORT FLOODING TO THE COUNTY SHERIFF...LOCAL POLICE...OR
DEPARTMENT OF PUBLIC SAFETY. THEY WILL RELAY YOUR REPORT TO THE
NATIONAL WEATHER SERVICE.

LAT...LON 2942 9670 2959 9629 2978 9635 2990 9660
      2965 9685

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
225 PM CST SUN NOV 21 2004

DISCUSSION...
A COMPLICATED FORECAST AGAIN ACROSS SOUTHEAST TEXAS. THE PERSISTENT
BOUNDARY WHICH HAS REMAINED NEARLY STATIONARY ALONG THE COAST SINCE
EARLY SATURDAY WILL PUSH SLOWLY NORTH OVERNIGHT. HAVE LEANED TOWARD
THE SLOWER GFS SOLUTION IN THE MOVEMENT OF THIS BOUNDARY. THE RAIN
COOLED AIR TO THE NORTH OF THE BOUNDARY SHOULD HELP REINFORCE THE
BOUNDARIES POSITION SO CONFIDENCE IS LOW THAT MUCH NORTHERN MOTION
CAN BE EXPECTED OVERNIGHT. PWS ARE FORECAST TO CONTINUE TO SLOWLY
CLIMB TO BETWEEN 1.7-1.8 INCHES BY 6Z. WITH THE BOUNDARY IN PLACE
AND A SERIES OF UPPER LEVEL DISTURBANCES EMBEDDED IN THE SOUTHWEST
UPPER FLOW...IT SEEMS REASONABLE TO KEEP THE HIGH POPS IN PLACE. THE
GROUND REMAINS SATURATED AND ANY ADDITIONAL HEAVY RAIN WILL CAUSE
FLOODING SO AS A PRECAUTION...WILL MAINTAIN THE FFA OVERNIGHT. THE
AXIS OF HEAVIEST RAIN SHOULD BEGIN TO SHIFT SLOWLY NORTH OVERNIGHT
AND AFFECT AREAS THAT HAVENT RECEIVED AS MUCH RAIN. SEE THE WELL
WRITTEN QPFERD FOR MORE DETAILS ON THE EXPECTED HEAVY RAIN.

AS OF 2 PM...IT APPEARS THAT THE WIDESPREAD CONVECTION AFFECTING
WHARTON AND JACKSON COUNTIES HAS BEGUN TO WEAKEN. IF THE GFS IS
CORRECT...THIS RESPITE FROM THE RAIN WILL END AROUND 06Z WITH
ADDITIONAL DEVELOPMENT BETWEEN 06 AND 09Z. AT 19Z...SFC ANALYSIS
REVEALS ANOTHER WEAK BOUNDARY OVER THE EXTREME NORTHERN PORTION OF
THE CWA. PERHAPS THIS IS THE GENESIS OF THE SECONDARY BOUNDARY WHICH
THE ETA DEVELOPS AND FOCUSES PRECIP DEVELOPMENT ON LATER TONIGHT. IF
THAT IS THE CASE...PERHAPS POPS OVER THE SOUTH ARE TOO HIGH. SUFFICE
TO SAY...WITH NUMEROUS MESO-SCALE INFLUENCES...CONFIDENCE IS LOW.

GFS FORECAST SOUNDINGS HAVE K INDICES IN THE MID/UPPER 30S AND TTS
AROUND 50. IT APPEARS THAT THE GFS IS SUFFERING CONVECTIVE FEEDBACK
FOR MONDAY NIGHT...YET IT STILL LOOKS LIKE WIDESPREAD PRECIP FOR MON
NIGHT OVER THE NORTHERN 2/3RD OF THE CWA. THE DEEPER MOISTURE/BOUNDARY
SHOULD BE PULLED NORTHWESTWARD AWAY FROM THE COAST AS THE WEST COAST
TROF DEEPENS. SPC HAS HAS THE AREA OUTLOOKED IN SLT RISK ON
MON...BUT WILL LET THE NEXT SHIFT EXAMINE THINGS BEFORE MENTIONING
SEVERE IN THE ZONES. WILL UPDATE THE HWO THIS EVENING AND ADDRESS
LATEST FLOODING/SEVERE CONCERNS.

ON TUESDAY...THIS PATTERN FINALLY COMES TO A CLOSE AS THE UPPER TROF
OUT WEST PUSHES NORTHEAST. A SURFACE COLD FRONT WILL CROSS THE AREA
TUESDAY BRINGING A SQUALL LINE ACROSS THE AREA LATE TUES MORNING
INTO THE AFTERNOON. DYNAMICS LOOK IMPRESSIVE AND A HIGH WIND EVENT
LOOKS POSSIBLE. ANYONE ELSE TIRED OF OUR LITTLE EL NINO?

THE REST OF THE WEEK LOOKS GREAT WITH DRIER AIR AND COOLER TEMPS. BY
THURSDAY...IT LOOKS LIKE WE WILL ALL HAVE REASON TO GIVE THANKS.

.MARINE...
PRESSURE GRADIENT IS EXPECTED TIGHTEN AS THE UPPER TROUGH APPROACHES
THE SOUTH CENTRAL U.S. THIS WEEK. EXPECT WINDS OVER THE GULF WILL
REMAIN IN THE 15 TO 20 KNOT RANGE FOR THE NEXT COUPLE OF DAYS.
OFFSHORE WIND WILL FOLLOW THE FRONT TUESDAY NIGHT/WEDNESDAY MORNING
AND SPEEDS MAY INCREASE TO MORE THAN 20 OR 25 KNOTS. SMALL CRAFT
ADVISORY CONDITIONS ARE LIKELY BY MID WEEK.

&&

.AVIATION...
PRECIPITATION AND CEILINGS WILL CONTINUE TO PLAY HAVOC WITH THE TAFS
FOR THE NEXT 24 HOURS. A LARGE CLEARING IN THE OVERCAST HAS
DEVELOPED OVER COLLEGE STATION. WITH AFTERNOON HEATING...ADDITIONAL
CLOUDS ARE LIKELY TO REDEVELOP OVER THERE A BIT LATER THIS
AFTERNOON. ALL THE OTHER AIRPORTS ARE DEALING WITH THE PRECIPITATION
AND SHOULD CONTINUE THROUGH THE AFTERNOON. THERE MAY BE A BRIEF
BREAK IN THE ACTIVITY LATER THIS AFTERNOON AND EVENING...BUT MORE
RAIN AND LOW CEILINGS ARE LIKELY AGAIN IN THE MORNING HOURS. 46

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH HGX CWA THROUGH 430 AM MONDAY.
SCEC HIGH ISLAND TO MATAGORDA SHIP CHANNEL 0-20 NM WATERS.
SCA  HIGH ISLAND TO MATAGORDA SHIP CHANNEL 20-60 NM WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 66 73 65 73 51 / 70 80 80 70 05
HOUSTON (IAH)         67 74 67 76 52 / 70 60 60 70 05
GALVESTON (GLS)       72 76 72 76 59 / 50 50 30 70 05

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
400 PM CST SUN NOV 21 2004

TXZ163-164-176>179-195>200-210>214-226-227-235>238-221030-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-GALVESTON-
GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-MADISON-MATAGORDA-MONTGOMERY-
POLK-SAN JACINTO-TRINITY-WALKER-WALLER-WASHINGTON-WHARTON-
338 PM CST SUN NOV 21 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST TEXAS.

.DAY ONE...TONIGHT.
A WARM FRONT WILL SERVE AS A FOCUS FOR ADDITIONAL SHOWERS AND
THUNDERSTORMS LATER TONIGHT AND EARLY MONDAY. THERE WILL BE A
BREAK IN THE RAINFALL THIS EVENING BEFORE ADDITIONAL RAIN
DEVELOPS AFTER MIDNIGHT. HEAVY RAIN WILL FOCUS ALONG THE BOUNDARY
WHICH IS CURRENTLY FORECAST TO LIE ALONG A VICTORIA TO HOUSTON TO
CLEVELAND LINE. 2 TO 4 INCHES OF RAIN IS POSSIBLE ALONG THIS LINE WITH
LESSER AMOUNTS TO THE SOUTH. DUE TO SO MANY MESO-SCALE BOUNDARIES...
CONFIDENCE IS LOW ON WHERE THE HEAVY RAIN AXIS WILL DEVELOP.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY...
AS THE WARM FRONT MOVES NORTH...THE AXIS OF HEAVY RAIN WILL ALSO
SHIFT NORTH. AREAS NORTH OF A BRENHAM TO CONROE TO LIVINGSTON LINE
CAN EXPECT RAINFALL TOTALS OF 2 TO 3 INCHES BY MONDAY EVENING WITH
LESSER AMOUNTS TOWARD THE COAST. THE FLOOD WATCH WILL LIKELY BE
EXTENDED ON MONDAY.

THERE IS ALSO SOME POTENTIAL FOR SEVERE THUNDERSTORMS ON MONDAY AND
AGAIN TUESDAY. THE PRIMARY THREAT FOR SEVERE WEATHER ON MONDAY WILL
BE ISOLATED TORNADOES. AT THIS TIME...AREAS SOUTHEAST OF AN EDNA TO
CONROE TO LIVINGSTON ARE MOST FAVORED FOR TORNADIC THUNDERSTORMS.
THIS THREAT AREA WILL MOVE INLAND TOWARD LATE AFTERNOON. A SQUALL
LINE IS EXPECTED TO DEVELOP ALONG A COLD FRONT ON TUESDAY. THIS
FEATURE WILL RACE ACROSS SOUTHEAST TEXAS BY MID AFTERNOON. THESE
STORMS HAVE THE POTENTIAL TO PRODUCE STRONG DAMAGING WINDS AND
ISOLATED TORNADOES.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE NEEDED MONDAY.