Flash Flood Warning 22, NWS Houston/Galveston, TX

942 
WGUS74 KHGX 292222
FFSHGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
522 PM CDT THU MAR 29 2012

TXC201-339-292231-
/O.CAN.KHGX.FF.W.0022.000000T0000Z-120329T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HARRIS TX-MONTGOMERY TX-
522 PM CDT THU MAR 29 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR EXTREME
SOUTHEASTERN MONTGOMERY AND EASTERN HARRIS COUNTIES IS CANCELLED...

DOPPLER RADAR INDICATES THAT HEAVY RAINFALL HAS COME TO AN END 
ACROSS THE WARNED AREA...AND THE HARRIS COUNTY SHERIFF'S OFFICE 
REPORTS NO FLOODING OR ROAD CLOSURES. IF FLOODING IS STILL 
OBSERVED...PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

&&

PLEASE REPORT SEVERE WEATHER TO THE COUNTY SHERIFF...LOCAL POLICE...
OR DEPARTMENT OF PUBLIC SAFETY AND ASK THEM TO RELAY YOUR REPORT TO
THE NATIONAL WEATHER SERVICE.

LAT...LON 3010 9515 2996 9500 2962 9510 2960 9515
      2977 9542 2986 9546 2995 9540 3002 9535
      3010 9527

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
117 PM CDT THU MAR 29 2012

.AVIATION...
CLUSTER OF STORMS CONTINUES TO ORGANIZE AND BOW OUT OVER THE
COASTAL COUNTIES AND NEARING LBX SHORTLY. EXPECT SCATTERED
SHRA/TSRA TO CONTINUE TO FORM OVER THE IAH TERMINALS NORTHWARD
THIS AFTERNOON AS UPPER S/W TRACKS EAST. A FEW WRF MODELS HIT THE
REDEVELOPMENT HARD OVER THE IAH/HOU/CXO TERMINALS THIS AFTERNOON
WITH AN EAST WEST BOUNDARY. NOT AS CONFIDENT THAT THIS WILL PAN
OUT GIVEN THE ORGANIZATION OF THE MESOSCALE FEATURE OVER THE
COASTAL COUNTIES. MAY BE MORE POPCORN/SCATTERED OVER THE
TERMINALS IAH NORTH THIS AFTERNOON. S/W DEPARTS THE AREA AND
EXPECT PRECIP TO END QUICKLY OVER THE SOUTH AND LINGER THROUGH 00Z
OVER THE NORTH THEN WANE. EXPECT THAT CIGS WILL LOWER OVERNIGHT
AND DROP INTO MVFR/IFR MOST LOCATIONS. FRIDAY AFTER 12Z SOME
POTENTIAL FOR WIDELY SCATTERED SHRA DEVELOPING AS IT WARMS AND
DESTABILIZES THOUGH THE UPPER FLOW SHOULD BE DOMINATED BY THE
TROUGH PASSAGE.
45

&&

.PREV DISCUSSION... /ISSUED 1058 AM CDT THU MAR 29 2012/

DISCUSSION...
ACTIVE PATTERN CONTINUING ON INTO THIS AFTN AS THE PCPN OVER THE
NRN ZONES MOVE OUT AND THE STORMS OVER THE SRN HALF KEEP DEVELOP-
ING. ALL OF THIS COURTESY OF THE WEAK SHORTWAVE ENERGY COMING UP
VIA THE SWLY FLOW ALOFT. SHORT TERM GUIDANCE SUGGESTING THAT THE
BEST CHCS FOR STORMS THIS AFTN/EVENING WILL BE OVER THE SRN HALF
OF THE CWA...AND GIVEN THE TRENDS THUS FAR HARD TO ARGUE WITH IT.
MAIN THREATS WITH THESE STORMS APPEAR TO BE LOCALLY HEAVY RAINS/
PERHAPS HAIL. 41

PREV DISCUSSION... /ISSUED 340 AM CDT THU MAR 29 2012/

A SLOW MOVING SHORTWAVE TROUGH ALLOWED SCT THUNDERSTORM ACTIVITY
OVER NORTHERN PORTIONS OF SE TX LAST NIGHT INTO EARLY THIS
MORNING. LOCALLY HEAVY RAINFALL CAUSED SOME FLOODING IN CALDWELL
AS WELL AS DROPPING 2.17 INCHES OF RAIN AT KCLL. THIS BRINGS
KCLL'S MONTHLY RAINFALL TO 8.56 INCHES WHICH IS A NEW RECORD FOR
THE MONTH OF MARCH. SEE THE CLIMATE SECTION FOR MORE DETAILS.

GIVEN THE TRENDS OF WEAK VORT MAXES COMING OUT OF MEXICO WHICH
THE MODELS ARE HAVING A DIFFICULT TIME RESOLVING AND THEN
DETERMINING THEIR EVOLUTION...THINK THE GFS HAS THE BEST HANDLE
ON THE CURRENT TRENDS. THE NAM SEEMS TO BE TOO WEAK WITH ANY OF
THESE DISTURBANCES AND THE ECMWF HAS BEEN TOO STRONG RESULTING IN
HIGHER QPF. GFS HAS WEAK DISTURBANCE MOVING OVER THE AREA TODAY
WITH STILL 1.4 TO 1.6 INCHES OF PRECIP WATER. THINK SCT
THUNDERSTORM ACTIVITY WILL BE A GOOD POSSIBILITY WITH SOME
LOCALIZED HEAVY RAINFALL AMOUNTS LIKE WHAT WAS OBSERVED LAST
NIGHT. POPS WERE BUMPED UP TO 50 PERCENT THIS AFTERNOON WITH 30
PERCENT OVERNIGHT. GFS HOLDS ON TO SOME BROAD TROUGHING OVER TX
INTO FRI AND SAT BUT LIFT LOOKS RATHER WEAK. AS A RESULT MAY SEE
MORE ISO THUNDERSTORM ACTIVITY FRI/SAT WITH SOME BRIEF HEAVY
DOWNPOURS SINCE DEEPER MOISTURE REMAINS OVER THE AREA. AS SUCH
TRIMMED BACK POPS TO 30 PERCENT BUT STILL LEARY OF VERY LOCALIZED
HEAVY RAINFALL.

MODELS AGREE WITH A DEEPENING TROUGH OVER THE 4 CORNERS SUN WHICH
WILL ALLOW FOR LEE CYCLOGENESIS OVER THE PLAINS. EXPECT LLJ TO
INCREASE SUN NIGHT INTO MON WHICH WILL KEEP TEMPS MILD OVERNIGHT.
GFS HAS PRETTY STRONG FRONTAL PASSAGE MON AFTERNOON SO WILL NEED
30/40 POPS FOR THE FRONTAL PASSAGE. CAP SHOULD INCREASE DURING
THE DAY AS BOUNDARY LAYER FLOW VEERS TO THE SW BUT STILL THINK
THERE COULD BE A SOLID LINE OF STORMS WITH THE FRONT. SFC RIDGE
BUILDS OVER TX ON TUE WITH MUCH DRIER AIRMASS IN PLACE. TEMPS
THAT HAD BEEN AVERAGING A GOOD 5-10 DEGREES ABOVE NORMAL SHOULD
DROP BACK TO CLIMO NORMS WITH LOWS IN THE 50S AND HIGHS IN THE
UPPER 70S.

39

CLIMATE...
COLLEGE STATION ESTABLISHED A NEW MONTHLY RAINFALL RECORD FOR
MARCH. KCLL RECEIVED 2.17 INCHES OF RAIN YESTERDAY AND THIS
BRINGS THE MONTHLY RAINFALL TOTAL TO 8.56 INCHES AND THIS BREAKS
THE PREVIOUS MARCH RAINFALL RECORD OF 8.03 INCHES SET IN 1926.
COLLEGE STATION HAS NOW RECEIVED MORE RAIN IN THE FIRST 3 MONTHS
OF 2012 (20.64 INCHES) THAN IT RECEIVED IN ALL OF 2011 (19.01).
GALVESTON IS STILL ON TRACK TO RECORD ITS SECOND WARMEST MARCH ON
RECORD. 43

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      79  66  81  67  83 /  50  50  30  20  20
HOUSTON (IAH)              80  66  82  67  82 /  50  50  30  20  20
GALVESTON (GLS)            76  70  78  71  77 /  50  50  30  20  20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

DISCUSSION...41
AVIATION/MARINE...45

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
453 AM CDT THU MAR 29 2012

TXZ163-164-176>179-195>200-210>214-226-227-235>238-301000-
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-
453 AM CDT THU MAR 29 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME. AN UPPER LEVEL
DISTURBANCE WILL HELP TO GENERATE SHOWERS AND THUNDERSTORMS
ACROSS PORTIONS OF SOUTHEAST TEXAS. SOME OF THE STORMS WILL HAVE
THE POTENTIAL TO BECOME STRONG WITH LOCALLY HEAVY RAINFALL.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. ANOTHER UPPER
LEVEL DISTURBANCE IS EXPECTED TO MOVE ACROSS SOUTHEAST TEXAS
THURSDAY NIGHT INTO FRIDAY. SHOWERS AND A FEW THUNDERSTORMS WILL
BE POSSIBLE AND SOME OF THE STRONGER STORMS WILL BE CAPABLE OF
PRODUCING LOCALLY HEAVY RAINFALL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1002 AM CDT THU MAR 29 2012

TXZ226-235-236-291600-
JACKSON-MATAGORDA-WHARTON-
1002 AM CDT THU MAR 29 2012

...SIGNIFICANT WEATHER ADVISORY...

AT 959 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
RAPIDLY DEVELOPING THUNDERSTORM OVER EAST CENTRAL JACKSON
COUNTY...NEAR LA WARD MOVING NORTHEAST AT 15 MPH.

PEA SIZE HAIL...WINDS GREATER THAN 40 MPH...BRIEF HEAVY
DOWNPOURS...ARE POSSIBLE WITH THIS STORM. RAINFALL RATES OF 2 INCHES
PER HOUR WILL BE POSSIBLE WITH THIS STORM.

LOCATIONS IN THE PATH OF THIS STORM INCLUDE...MIDFIELD...LOUISE...
BLESSING AND LA WARD.

GUSTY WINDS MAY CAUSE UNSECURED SMALL OBJECTS SUCH AS TRASH CANS TO
BLOW AROUND. SEEK SHELTER IN A STURDY STRUCTURE OR NON-CONVERTIBLE
AUTOMOBILE UNTIL THIS STORM HAS PASSED.

LAT...LON 2920 9634 2889 9607 2877 9642 2891 9656
TIME...MOT...LOC 1502Z 228DEG 12KT 2890 9641