Flash Flood Warning 11, NWS Houston/Galveston, TX

SOUTHEAST TEXAS FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
825 PM CDT WED JUN 6 2001

WILL HAVE ONLY VERY MINOR CHANGES IN 9 PM UPDATE.

LATEST NFD DISCUSSION OF T.D. ALLISON HAS STORM BECOMING STATIONARY
OVER SE TX... AS MODELS HAVE PREDICTED FOR SOME TIME.  PROBLEM BEING
THAT THE MODELS ARE UNABLE TO BE AS ARTICULATE AS WE WOULD LIKE WITH
THE WANDERING LOW EITHER AT THE SURFACE OR ALOFT.  AS FOR THE PRECIP
WITH THIS SYSTEM, IT HAS FAITHFULLY TRACKED WITH THE 700 MB
CIRCULATION FOR THE PAST 30 HOURS WHILE THE SURFACE CIRCULATION HAS
BEEN OF LITTLE OR NO CONSEQUENCE, BUT MODELS SHOW AS MUCH VARIANCE
WITH 700 MB CIRCULATION AS ANYTHING ELSE, THE ONLY CONSTANT BEING
THE QUASI-STATIONARY NATURE OF THE FORECASTS.

THE 18Z RUNS ADDED NOTHING OF IMPORT TO PREVIOUS DISCUSSION, AND THE
FACT THAT THE LITTLE BIT OF CONVERGENCE SET UP BY THE SEABREEZE AND
THE WEAK CIRCULATION AROUND THE T.D. WAS SUFFICIENT TO FIRE UP A
BAND OF HEAVY SHOWERS AND THUNDERSTORMS THIS AFTERNOON FROM JUST E
OF HOUSTON TO WEST OF FORT POLK REINFORCES THE ARGUMENT FOR THE EASE
WITH WHICH CONVECTION MAY FIRE ON THURSDAY WHEN UPPER SUBSIDENCE ON
SOUTH AND SOUTHWEST SIDES OF UPPER CIRCULATION WILL NOT BE AS MUCH
AN ISSUE AS TODAY.  AND OF COURSE, FOR WHAT ITS WORTH, ALL THE
NUMERICAL GUIDANCE ALSO ANTICIPATES REDEVELOPMENT OF PRECIP TOMORROW
OVER MUCH OF THE REGION.  GIVEN THE WEAKNESS OF THE MODELS IN THESE
LATITUDES IN SUMMER - WELL ITS ALMOST SUMMER - AND WITH THESE
WEAK CIRCULATIONS IN PARTICULAR, HARD TO FORECAST TIMING, INTENSITY,
OR EXTENT WITH ANY PRECISION - JUST THE CONFIDENCE THAT IT WILL
HAPPEN BECAUSE THE CONDITIONS ARE ALL RIPE EVEN IF THE MODELS ALL
TURN OUT... IN VARYING DEGREES... TO BE WRONG.

AND UNFORTUNATELY, NOT MUCH TO BE GAINED BY MERE OLD FASHIONED HAND
ANALYSIS AND LOOKING AT LAST 12 HOURS OF SATELLITE IMAGERY AND GOING
BY EXTRAPOLATION, SINCE SYSTEM IS ALREADY NEARLY STATIONARY.

AS SUCH, THUNDERSTORMS, SOME CARRYING NEARLY 1/HR RAINFALL AMOUNTS
CONTINUE TO AFFECT THE COUNTIES UNDER THE CURRENT FFA AND AM
INCLINED TO RETAIN THE CURRENT FFA IN PLACE TONIGHT EVEN THOUGH AS
PREVIOUS DISCUSSION NOTES, THIS SYSTEM IS COLD CORE AT 700 MB, AND
THOUGH IT DOES NOT SHOW A DEFINITIVE THERMAL CORE IN MODELS AT 500
MB DIRECTLY ASSOCIATED WITH 500 MB CIRCULATION, 500 MB TEMPS OVER E
TX ARE COOLER THAN THOSE E-W-N.  STILL, WILL WAIT AND SEE IF
CONVECTION IS INCLINED TO TAKE A GRADUAL DIMINISHING TREND AFTER
SUNSET BEFORE CONSIDERING TERMINATING OR RECONFIGURING THE CURRENT
FFA.

38/36/BT

.KHGX...FFA NE ZONES TNGT.

PRELIMS...
CLL TT 071/086 071/086 071 566
IAH TT 072/086 073/085 073 466
GLS TT 076/084 076/084 076 356