FXUS64 KSHV 150352
AFDSHV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
952 PM CST MON DEC 14 2009
.DISCUSSION...
FRONT MAKING GOOD PROGRESS WITH ABOUT A 50 MILE LAG IN THE COLD
AIR BEHIND THE WIND SHIFT. FRONT NOW LOCATED FROM LUFKIN TO
NATCHITOCHES TO MONROE. AREAS ACROSS THE NORTHWEST COUNTIES ALREADY
IN THE 30S. INTERESTINGLY...THERE IS A LAG IN THE DRIER AIR
WORKING INTO SW ARKANSAS THROUGH TEXARKANA. VERY DENSE FOG HAS
DEVELOPED IN CALM WINDS ACROSS THE REGION. RECEIVED A REPORT FROM
THE EMERGENCY MANAGER IN HOWARD COUNTY OF VISIBILITIES OF ONLY A
HUNDRED FEET. THIS SHOULDNT LAST LONG AS THE DRIER AIR WORKS IN
AND MIXES OUT THE FOG. MAY STILL SEE SOME OVERRUNNING AS SOUTHWEST
FLOW ALOFT PERSISTS OVER TOP OF THE COLD AIR AT THE SURFACE WHICH
IS INFILTRATING THE AREA. OKC AND SGF 00Z SOUNDINGS INDICATE THE
ARCTIC AIRMASS IS ONLY ABOUT 75 TO 100 MB THICK OR ABOUT 2500
FEET. WITH OVERALL THICKNESSES DECREASING AND MOISTURE STILL
PRESENT AT THE TOP OF THE AIRMASS...THINK CHANCE POPS ARE STILL
POSSIBLE THROUGH MORNING AS SLIGHT ISENTROPIC LIFT STILL EXISTS.
WILL STICK WITH CHANGES IN THE ZONES MADE EARLIER THIS EVENING OF
ADDING PATCHY FOG THROUGH MIDNIGHT FOR SOUTH AND EAST ZONES AND AN
OVERALL DECREASE IN POPS.
&&
.AVIATION...
RAIN IS REMAINING SOUTH OF THE FORECAST AREA THIS EVENING...AHEAD OF
A SOUTHWARD MOVING FRONT. AT MID EVENING...THE FRONT IS NEARING A
MLU TO LFK LINE. CIGS AND VSBYS AHEAD OF THE FRONT ARE MOSTLY IFR.
AFTER FRONTAL PASSAGE...FLIGHT CONDITIONS SHOULD IMPROVE TO MVFR...
AND LATER TONIGHT VFR AS THE FRONT BRINGS IN A DEEPER LAYER OF DRY
AIR. BY 12Z MOST TAFS SITES SHOULD BE VFR...WITH MAYBE EXCEPTIONS AT
MLU AND LFK...WHICH SHOULD BECOME VFR BY 15Z. ANY ADDITIONAL
RAINFALL OVERNIGHT SHOULD BE CONFINED TO DEEP EAST TEXAS INTO
NORTHCENTRAL LOUISIANA.
EXPECT SURFACE WINDS TO BECOME NORTHERLY ALL AREAS BY 06Z...
GENERALLY AROUND 10 KTS. SPEEDS SHOULD INCREASE ON TUESDAY INTO THE
10 TO 15 KT RANGE BY 14Z WITH GUSTS 20 TO 25 KTS AT TIMES...AS COLD
AIR ADVECTION TAKES PLACE. /14/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 44 49 34 53 33 / 30 20 0 0 0
MLU 45 48 34 51 34 / 40 30 0 0 0
DEQ 35 46 25 52 30 / 10 10 0 0 0
TXK 39 48 28 51 31 / 10 10 0 0 0
ELD 40 49 29 51 31 / 20 10 0 0 0
TYR 41 50 33 54 34 / 20 10 0 0 0
GGG 42 50 34 53 33 / 30 10 0 0 0
LFK 49 51 37 55 36 / 40 30 0 0 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
04/14