National Weather Service Raw Text Product

Bulk Download

PIL:
Start UTC Date @0z:
End UTC Date @0z:
501 
FXUS64 KHGX 232154
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
354 PM CST THU JAN 23 2014

...WINTER STORM WARNING IN EFFECT UNTIL NOON FRIDAY...

.DISCUSSION...
COLD FRONT HAS PUSHED OFF THE COAST AND TEMPERATURES CONTINUE TO
DROP. THERE IS STILL QUITE A BIT OF PRECIPITATION ACROSS THE AREA
AND EVEN SOME REPORTS OF SNOW MIXED WITH RAIN. UPPER LEVEL TROUGH
OVER THE PLAINS SHOULD SLOWLY SWING TOWARDS N TX TONIGHT WITH
FAVORABLE JET DYNAMICS FOR LARGE SCALE LIFT. COLD AIRMASS WILL
CONTINUE TO FILTER INTO THE REGION WITH TEMPS DROPPING BELOW
FREEZING CONROE NORTHWARD MAINLY AROUND 9PM. FREEZING TEMPS THEN
WORK NORTH TO SOUTH ACROSS THE AREA AFTER MIDNIGHT FOR HOUSTON
ALTHOUGH IT COULD HAPPEN SOONER WITH PRECIP FALLING AND WET BULB
THERMODYNAMIC PROCESSES. THERE IS QUITE A BIT OF DRY AIR JUST
NORTH OF THE AREA WITH DEWPOINTS IN THE TEENS. MODELS CONSISTENTLY
KEEPING THIS DRIER AIR OUT OF THE AREA OR SLOWLY MOVING IN MIXING
WITH MOIST BOUNDARY LAYER AS IT DOES SO. THE RESULT IS FAVORABLE
CONDITIONS FOR ONGOING PRECIPITATION.

AS JET DYNAMICS SET UP OVER THE AREA WITH RIGHT  ENTRANCE REGION
OVER THE AREA...NAM CONTINUES TO BE ROBUST WITH ISENTROPIC LIFT.
GFS NOT AS MUCH BUT STILL ENOUGH TO GENERATE A SOLID 0.1 TO 0.25
OF PRECIPITATION OVER THE AREA THROUGH 12Z FRI. NAM ALSO HAS QUITE
A BIT OF FRONTOGENESIS IN SEVERAL LAYERS MAINLY 850MB-700MB
PEAKING AROUND 06Z THROUGH 12Z. THE MAIN ISSUE BEFORE WAS WOULD
THERE BE ENOUGH LIFT FOR PRECIP AND WHETHER DRY SUB FREEZING LAYER
WOULD KEEP PRECIP FROM REACHING GROUND. THAT HAS CHANGED AND AS A
RESULT WINTER STORM WARNING CRITERIA LOOKS TO BE MET ACROSS THE
AREA. LIFT AND FORCING SEEMS TO WEAKEN AFTER 18Z FRI SO EXPECT
PRECIP TO END IN THE AFTERNOON AND EVENING. NAM STILL HOLDS ONTO
PRECIP LONGER ALONG THE COAST IN THE AFTERNOON THAN THE GFS/ECMWF.

PRECIPITATION TYPE...THINK AREAS NORTH OF CONROE WILL START WITH
RAIN TRANSITION TO MIX SLEET/FZRA UNTIL 06Z FRI. MAY THEN SEE A
TRANSITION TO SNOW/SLEET AFTER MIDNIGHT UNTIL THE MORNING HOURS.
POSSIBLE TO HAVE A BAND OF 1 INCH SNOW ACCUMULATIONS FROM
CALDWELL/COLLEGE STATION ACROSS HUNTSVILLE TO LIVINGSTON. ICE
ACCUMULATION MAY NOT BE THAT MUCH BUT STILL ENOUGH TO MAKE A MESS
OF TRAVEL CONDITIONS.

PRECIPITATION TYPE...BASICALLY CONROE SOUTH THOUGH HOUSTON TO THE
COAST EXPECT RAIN GOING TO FZRA/SLEET APPROACHING MIDNIGHT WHEN
TEMPS DROP BELOW FREEZING AT SFC. MODEL SOUNDINGS ARE NOT ALL THAT
SUPPORTIVE OF SNOW BUT SUPPOSE A FLAKE OR TWO COULD MIX IN WITH
SLEET. ISENTROPIC LIFT WITH WARM NOSE AROUND 850-800MB IN
SOUNDINGS SHOULD SUPPORT SLEET AND DEPENDING ON DEPTH OF
SUBFREEZING LAYER...FREEZING RAIN CLOSER TO THE COAST. POSSIBLE TO
GET FREEZING RAIN AS FAR SOUTH AS GALVESTON BY 12Z FRI WHICH COULD
CAUSE FURTHER TRAVEL ISSUES.

ACCUMULATIONS...OVERALL EXPECT HALF INCH TO 1 INCH OF SNOW FOR
NORTHERN AREAS AS OUTLINED ABOVE. GIVE MESO MODEL OUTPUT FROM TX
TECH WRF AND RECENT HRRR RUNS...EVEN 2 INCHES MAY BE POSSIBLE IN A
FEW SPOTS. FOR ICE ACCUMULATIONS GENERAL 0.05 TO 0.2 INCHES OF ICE
WILL BE POSSIBLE MAINLY ALONG I-10 AND US59 AND BACK TOWARDS
HOUSTON. LOWER AMOUNTS WILL BE POSSIBLE ALONG THE COAST BUT STILL
A RISK MAINLY FRIDAY MORNING.

WEEKEND DOES LOOK TO BE WARMER AFTER FRIDGID FRIDAY. NEXT FRONT
STILL ON SCHEDULE FOR MONDAY WHICH WILL PUT MIN TEMPS BACK BELOW
FREEZING FOR TUESDAY AND WEDNESDAY. DOES NOT LOOK LIKE A WINTER
WEATHER SCENARIO AS ANY PRECIP WILL BE PUSHED OUT WITH FRONT.

39

&&

.AVIATION...
ALREADY SEEING SNOW IN CLL OBS THIS AFTN. HAVE BEEN ADJUSTING
PCPN TYPES/TIMES WITH AMENDMENTS THUS FAR. END TIMES FOR THE
WINTRY MIX MAY HAVE TO BE EXTENDED PAST THE 15Z CURRENTLY IN THE
TAFS FOR TO- MORROW...ESPECIALLY FOR THE NRN SITES (CLL/UTS/CXO).
41

&&

.MARINE...
WENT AHEAD WITH THE GALE WARNING FOR ALL OUR MARINE AREAS WITH THE 
MORNING UPDATE AND NO CHANGES FROM THE CURRENT CONFIGURATIONS WILL 
BE COMING WITH THIS NEXT PACKAGE. STILL EXPECTING WINDS/SEAS TO DE- 
CREASE BY TOMORROW/FRI AFTN AS HIGH PRESSURE SETTLES OVER THE AREA 
FROM THE NORTH. A LIGHT ONSHORE FLOW TO RETURN LATE IN THE WEEKEND 
BUT SHOULD BE SHORT-LIVED AS ANOTHER COLD FRONT MOVES ACROSS SE TX 
AND INTO THE COASTAL WATERS SUN OVERNIGHT/VERY EARLY MON. 41

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      26  36  29  60  41 /  70  30  10  10  10 
HOUSTON (IAH)              28  35  30  60  41 /  80  50  10  10  10 
GALVESTON (GLS)            30  37  36  56  48 /  70  60  20  10  10 

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WINTER STORM WARNING UNTIL NOON CST FRIDAY FOR THE FOLLOWING 
     ZONES: BRAZOS...BURLESON...GRIMES...HOUSTON...MADISON...
     TRINITY...WALKER...WASHINGTON.

     WIND ADVISORY UNTIL 6 AM CST FRIDAY FOR THE FOLLOWING ZONES: 
     BRAZORIA...CHAMBERS...FORT BEND...GALVESTON...HARRIS...
     JACKSON...MATAGORDA...WHARTON.

     WINTER STORM WARNING FROM 9 PM THIS EVENING TO NOON CST FRIDAY 
     FOR THE FOLLOWING ZONES: AUSTIN...BRAZORIA...CHAMBERS...
     COLORADO...FORT BEND...GALVESTON...HARRIS...JACKSON...
     LIBERTY...MATAGORDA...MONTGOMERY...POLK...SAN JACINTO...
     WALLER...WHARTON.

GM...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR THE 
     FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS 
     FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 
     NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 
     20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
     WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.

     SMALL CRAFT ADVISORY FROM 3 AM TO NOON CST FRIDAY FOR THE 
     FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS 
     FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...
     WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.

     GALE WARNING UNTIL 3 AM CST FRIDAY FOR THE FOLLOWING ZONES: 
     GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE 
     MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM 
     FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS 
     FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH 
     ISLAND TO FREEPORT OUT 20 NM.

     SMALL CRAFT ADVISORY FROM 3 AM TO 5 PM CST FRIDAY FOR THE 
     FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP 
     CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO 
     FREEPORT 20 TO 60 NM.

&&

$$

DISCUSSION...39
AVIATION/MARINE...41