Afternoon HGX AFD:
AFDHGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
352 PM CST MON DEC 2 2013
.DISCUSSION...
SW FLOW IN THE BOUNDARY LAYER HAS SUPPORTED TEMPS IN THE UPPER 70S
FOR MOST AREAS. GULF MOISTURE HAS ALSO INCREASED ALONG THE COAST
BASICALLY SOUTH OF I-10 WHERE DEWPOINT TEMPS ARE IN THE LOW 60S.
AREAS FROM COLLEGE STATION TO HUNTSVILLE HAVE HAD DEWPOINT TEMPS
MIX OUT DOWN INTO THE UPPER 40S. THERE SHOULD BE ENOUGH RECOVERY
IN MOISTURE OVERNIGHT THAT PATCHY FOG WILL BE POSSIBLE AGAIN. THE
MAIN ISSUE IS IF WINDS STAY AROUND 5KTS FROM THE SOUTH.
MOISTURE WILL GRADUALLY INCREASE WED/THUR SO POSSIBLE TO HAVE FOG
EACH OF THOSE NIGHTS DEPENDING ON WINDS. TEMPS TOMORROW SHOULD BE
BACK INTO THE UPPER 70S TO LOW 80S. TEMPS AT 850MB WARM TO AROUND
17-18C TOMORROW SO THINK LOW 80S LOOKS REASONABLE. RECORD HIGH
TEMP AT KIAH IS 85 AND 86 AT KCLL. DO NOT THINK IT WILL GET THAT
WARM. WILL KEEP SOME 20 POPS FOR A FEW SHOWERS ON WED BUT REALLY
DO NOT EXPECT THERE TO BE MUCH ACTIVITY.
DRASTIC TEMPERATURE CHANGES ARE EXPECTED FOR THE END OF THE WEEK
BUT WILL OCCUR SLOWLY. THE 12Z MODELS WERE IN MUCH BETTER
AGREEMENT WITH THE FRONTAL PUSH. CANADIAN COLD FRONT WORKS INTO TX
ON WED AND STALLS NORTH OF THE AREA. THE NAM/ECMWF HAVE BEEN
CONSISTENT WITH A SLOWER PUSH THAN THE GFS BUT THE 12Z GFS IS NOW
SHOWING VERY SIMILAR TIMING. THIS BRINGS THE FRONT INTO KCLL AREA
AROUND 18Z THEN HOUSTON METRO AROUND 00Z FRI JUST IN TIME FOR RUSH
HOUR. BASED OFF MODEL SOUNDINGS THINK THERE COULD BE A FEW STORMS
ALONG AND AHEAD OF THE FRONT BUT INSTABILITY STILL RATHER LIMITED
ALTHOUGH THERE WILL BE QUITE A BIT OF DEEP LAYER SHEAR. OVERALL
JUST DO NOT SEE A LOT OF STORM ORGANIZATION WITH LIMITED
INSTABILITY. MAIN THREATS IF ANYTHING WILL BE SOME GUSTY WINDS AND
PERHAPS SOME SMALL HAIL IN STRONG STORMS BUT A SMALL PROBABILITY.
AS SUCH POPS ARE HELD AROUND 30-50 PERCENT ON THUR.
FRONT IS EXPECTED TO BE VERY SLOW MOVING AND ONLY BARELY PUSHING
OFF THE COST BY FRI MORNING. FRONT LOOKS TO HOLD PARALLEL TO MAIN
UPPER LEVEL FLOW GOING INTO FRI. COLD FRONT AT 850MB ONLY SLIGHTLY
PUSHES INTO THE AREA BUT OVERALL LOOKING AT A SHALLOW COLD AIRMASS
BELOW 850MB. FRONT WILL GET A BETTER PUSH DURING THIS TIME AS
RIGHT ENTRANCE TO JET APPROACHES WITH A SHORT WAVE TROUGH.
DIVERGENCE ALOFT SHOULD BE STRONG AND THINK FRI MORNING BEST
CHANCES FOR RAIN AT THIS TIME. FOR NOW 60 POPS LOOK ON TRACK BUT
COULD GO HIGHER NOW THAT MODELS ARE STARTING TO BE IN MORE
AGREEMENT. MODEL SOUNDINGS SUGGEST RAIN PRECIP TYPE MAINLY AS
COLDER SUB-FREEZING AIR WILL BE NORTH OF THE AREA.
SATURDAY ANOTHER JET STREAK MOVES BY WITH AGAIN RIGHT ENTRANCE
REGION FAVORABLE FOR LARGE SCALE ASCENT. ISENTROPIC ANALYSIS AT
290K HAS LIFT INCREASING OVER THE FRONTAL SURFACE. MODELS
SOUNDINGS SHOW A WELL PRONOUNCED WARM NOSE THROUGH A DEEP LAYER
ABOVE THE FRONT. THERE MAY BE A HINT OF A SUB-FREEZING LAYER JUST
OFF THE SURFACE FOR COLLEGE STATION TO CROCKETT ON SATURDAY BUT
DO NOT THINK IT WILL BE ENOUGH FOR FROZEN PRECIP. GIVEN THE SET UP
WILL KEEP WITH GENERALLY 30-40 POPS AS THERE IS NOT EXPECTED TO BE
MUCH IN THE WAY OF PRECIP. ANOTHER COLD FRONT IS EXPECTED TO PUSH
THROUGH WITH A MUCH DEEPER/COLDER AIRMASS BEHIND IT. EXPECT RAIN
CHANCES TO END SUN NIGHT PERHAPS EARLIER. OVERALL IT LOOKS LIKE A
COLD WET WEEKEND.
http://forecast.weather.gov/product.php ... glossary=1