Flash Flood Warning 50, NWS Houston/Galveston, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
459 AM CDT THU MAY 21 2015

.DISCUSSION...
COLD FRONT WHICH APPEARED TO BE SLIGHTLY AHEAD OF SCHEDULE LAST
NIGHT HAS SLOWED DOWN OVERNIGHT. THIS LINE (ALONG WITH ITS ASSO-
CIATED PCPN) SEEMS TO BE JUST ENTERING THE NRN PARTS OF THE CWA
ATTM...AND STILL EXPECTING ALL OF THIS ACTIVITY TO SPREAD SOUTH
WITH TIME TODAY. KEEPING POPS HIGH SIDE IN/AROUND THIS BOUNDARY
THESE NEXT COUPLE OF DAYS AS IT WILL REMAIN THE FOCUS FOR PCPN/
POSSIBLE LOCATIONS OF HEAVY RAINS. PWS PROGGED TO REMAIN AROUND
1.8" AS SHORTWAVES MOVE IN FROM THE SW. NOT RULING OUT THE POSS-
IBILITY OF ISO SEVERE STORMS THIS AFTN...BUT CLOUDINESS ALREADY
OVER THE THE AREA COULD LIMIT INSTABILITY SOME. BUT THE GREATER
CONCERN MAY BE THE LIKELIHOOD OF LOCALLY HEAVY RAINS OVER AREAS
STILL TRYING TO DRY OUT FROM RAINS THIS PAST WEEK. ADDITIONALLY
THIS SCENARIO COULD BE SETTING THE STAGE FOR POTENTIALLY BIGGER
PROBLEMS LATER (THIS UPCOMING WEEKEND).

AS THIS SFC BOUNDARY WASHES OUT/MOVES BACK NORTH ON SAT...STILL
LOOKING FOR JUST A SLIGHT BREAK IN THE ACTIVITY. BUT MODELS ARE
REMAINING VERY SALTY WITH THE PROSPECTS OF VERY HEAVY RAINS FOR
SUN/MON. THE PROGGED PWS NOW UP TO 2" AS THE UPPER FLOW BECOMES
VERY FAVORABLE WITH THE APPROACH OF THE MAIN UPPER LOW FROM THE
WEST. HOLDING OFF ON THE MENTION OF LOCALLY HEAVY RAINS FOR THE
GRIDS FOR TIME FRAME AS WE ARE STILL A WAYS OFF BUT WILL LIKELY
HIGHLIGHT THE POSSIBILITY IN THE UPCOMING HWO. UNFORTUNATELY...
ALL OF THIS IS HAPPENING ON THE HOLIDAY WEEKEND. 41

&&

.MARINE...
WINDS RELAXING THIS MORNING WITH MOST MARINE SITES AT 6-13 KNOTS
WITH A CORRESPONDING DROP IN SEAS. THIS PATTERN SHOULD PREVAIL
TODAY AS WINDS BACK SLIGHTLY AHEAD OF A COLD FRONT SAGGING INTO
SETX. EXPECT STORMS TO REDEVELOP THIS AFTERNOON ALONG THE
SEABREEZE AND COLD FRONT IN THE COASTAL COUNTIES. THESE STORMS MAY
EXTEND INTO THE BAYS WITH HEAVY DOWNPOURS AND SLOW MOVEMENTS. THE
FRONTAL BOUNDARY WASHES OUT ON FRIDAY AS IT LIFTS BACK SLOWLY
NORTHWARD. IMPRESSIVE UPPER LEVEL TROUGH MOVES INTO TEXAS LATE
THIS WEEKEND LEADING TO WINDS INCREASING FRIDAY AND WILL VERY
LIKELY WARRANT SCEC/SCA SATURDAY AND SCA SATURDAY NIGHT-MONDAY.
SUSTAINED WINDS AROUND 20 KNOTS WITH SEAS BUILDING TO 7 FEET. LLJ
LINES UP FROM NORTH TO SOUTH ACROSS THE AREA AND GUSTY WINDS
SHOULD ACCOMPANY THE WINDS THIS WEEKEND. WILL NEED TO KEEP AN EYE
OUT ON STORMS PROPAGATING EAST FROM THE AXIS OF DEEPEST/RICHEST
MOISTURE TRANSPORT (PROBABLY GREATEST THREAT OF THIS ON SUNDAY AND
MONDAY) AND INTO THE COASTAL WATERS AS A LARGE CLUSTER OF STRONG
STORMS. RUNUP AND PERSISTENT SE FLOW AND SWELL FETCH ALL POINT TO
ELEVATED TIDES AND STRONGER RIP CURRENTS OVER THE HOLIDAY WEEKEND.

45
&&

.AVIATION...
STORMS FIRING OFF ON OR JUST SOUTH OF THE FRONTAL BOUNDARY NEAR
CLL- DKR THIS MORNING. BOUNDARY SHOULD CONTINUE TO SAG SOUTHWARD
TURNING WINDS FROM L/V TO N TO NE. WIND SHIFT SHOULD REACH IAH BY
AROUND 17Z THEN BOUNDARY SHOULD STALL. THIS WILL LIKELY BECOME A
FOCUS FOR STORMS THIS AFTERNOON AND WILL CONTINUE TO MENTION
VCTS/TEMPO CONDITIONS 19-23Z FOR MOST OF THE SOUTHERN SITES. COULD
END UP WITH SOME SIGNIFICANT IMPACTS WITH SLOW MOVING/STATIONARY
STORMS BOTH EAST AND WEST OF THE MAJOR TERMINALS. STORMS SHOULD
WIND DOWN BETWEEN 23-02Z.

45
&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      81  70  82  71  84 /  60  40  50  30  40
HOUSTON (IAH)              85  72  83  72  84 /  60  30  40  20  30
GALVESTON (GLS)            83  77  82  77  83 /  60  30  30  20  20

&&

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

DISCUSSION...99