FXUS64 KSHV 152115
AFDSHV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
315 PM CST TUE DEC 15 2009
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
LOW-LEVEL COLD ADVECTION CONTINUES STREAMING INTO THE FORECAST AREA
THIS AFTERNOON...IN WAKE OF A COLD FRONT WHICH EXTENDED NEAR A
BROWNSVILLE TEXAS TO GREENVILLE ALABAMA LINE AT 3 PM. WITH AREA
RADARS SHOWING ALL OF THE PRECIPITATION SOUTH AND EAST OF OUR
AREA...ONLY A BLANKET OF STRATUS LINGERED BEHIND THE FRONT. AS THE
FRONT SETTLES OVER THE NORTHERN GULF...CLOUD COVER OVER THE SOUTHERN
TIER OF COUNTIES/PARISHES SHOULD GRADUALLY THIN. THE RESULT WILL
LIKELY BE COLDER TEMPERATURES ACROSS THE ENTIRE FORECAST AREA
TONIGHT.
COLD HIGH PRESSURE...CENTERED OVER MID-AMERICA THIS AFTERNOON...IS
FORECAST TO SHIFT INTO THE OHIO VALLEY THROUGH THE MIDDLE OF THE
WEEK. IN THE MEANTIME...A SHORTWAVE TROUGH OVER SOUTH TEXAS WILL
GRADUALLY SHIFT EASTWARD THROUGH THURSDAY. ADDITIONAL CLOUD COVER
WILL LIKELY START SPREADING NORTHEAST ACROSS OUR AREA WEDNESDAY
NIGHT/THURSDAY...AS PERTURBATIONS ASSOCIATED WITH THIS SYSTEM START
EJECTING ACROSS THE AREA.
A LITTLE BIT OF ISENTROPIC UPGLIDE MAY BE SEEN OVER OUR SOUTHERN
TIER OF COUNTIES AND PARISHES INTO THURSDAY...AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG THE OLD FRONT. IN RESPONSE...WE MIGHT SEE A
LITTLE BIT OF LIGHT RAIN DEVELOP ALONG THE COAST AND SPREAD
NORTHEASTWARD INTO THE SOUTHERN PART OF THE FORECAST AREA. THE BIG
QUESTION APPEARS TO REVOLVE AROUND THE AMOUNT OF AVAILABLE MOISTURE
FOR RAIN TO BE SEEN IN OUR AREA. GIVEN THE AMOUNT OF ENERGY
AVAILABLE FOR THIS STORM SYSTEM...SMALL RAIN PROBABILITIES WILL BE
INTRODUCED THURSDAY OVER THE SOUTHERN TIER OF COUNTIES/PARISHES EVEN
WITH THE UNCERTAINTY IN AVAILABLE MOISTURE. RAIN PROBABILITIES
SHOULD CONTINUE INTO THURSDAY /MAINLY SOUTH AND EAST/ AS THE WAVE OF
LOW PRESSURE MOVES ACROSS THE NORTHERN GULF.
ANOTHER SHORTWAVE TROUGH IS FORECAST TO DIVE SOUTHWARD INTO THE
PLAINS THURSDAY AND AID IN THE DEVELOPMENT OF A COLD FRONT ACROSS
THE HIGH PLAINS. THE FRONT SHOULD MOVE SOUTHEAST AND ACROSS OUR
AREA FRIDAY...AND BRING A REINFORCING SHOT OF DRIER AIR TO THE
REGION.
.LONG TERM /SATURDAY THROUGH TUESDAY/...
RELATIVELY QUIET WEATHER CONDITIONS ARE EXPECTED FOR DAYS 4 THROUGH
7. A DRIER AIRMASS SHOULD MOVE INTO THE REGION THIS WEEKEND...AS A
NORTHWESTERLY FLOW ALOFT PUSHES SURFACE HIGH PRESSURE INTO THE
REGION.
ANOTHER DISTURBANCE IS FORECAST TO DIVE SOUTHEAST TOWARD THE PLAINS
IN THE SUNDAY NIGHT/MONDAY TIME FRAME. THE ASSOCIATED COLD FRONT IS
FORECAST TO PUSH ACROSS THE FORECAST AREA MONDAY. THERE COULD BE A
LITTLE BIT OF LOW-LEVEL MOISTURE RETURN AHEAD OF THE SYSTEM. THAT
COULD ALLOW US TO SEE A SMATTERING OF PRECIPITATION AS THE FRONT
MOVES THROUGH. HOWEVER...I WILL KEEP THE FORECAST DRY FOR NOW SEE
IF THE MOISTURE RETURN IS A LITTLE BETTER IN SUBSEQUENT MODEL RUNS.
IN KEEPING WITH THE RATHER QUICK PROGRESSION OF THESE SYSTEMS...HIGH
PRESSURE SHOULD BUILD INTO THE FORECAST AREA TUESDAY UNDER A
NORTHWESTERLY FLOW ALOFT. /21/
&&
.AVIATION...
CLEARING SKIES BEHIND AN EJECTING COLD FRONT WILL LEAD TO VFR
CONDITIONS AT ALL SITES. WIND SPEEDS WILL COME BACK DOWN TO THE 5 TO
10 KNOTS RANGE LATER THIS EVENING. /23/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 34 52 34 53 38 / 0 0 10 10 10
MLU 33 50 32 50 34 / 0 0 10 10 30
DEQ 26 52 28 57 37 / 0 0 0 0 10
TXK 29 51 31 54 37 / 0 0 0 0 10
ELD 30 50 30 51 33 / 0 0 10 0 10
TYR 31 54 34 55 39 / 0 0 10 10 10
GGG 32 53 34 55 38 / 0 0 10 10 10
LFK 34 54 36 53 39 / 0 0 10 30 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
PUBLIC FORECASTER... D. BUTTS
AVIATION/FIRE WEATHER FORECASTER... DUPLANTIS
