FXUS64 KSHV 060405
AFDSHV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
1005 PM CST SAT DEC 5 2009
.DISCUSSION...
SE RETURN FLOW HAS COMMENCED ACROSS THE REGION THIS EVENING...ON THE
BACKSIDE OF A SFC RIDGE THAT HAS SHIFTED E OVER THE MS VALLEY.
MEANWHILE...WATCHING CIRRUS CANOPY INCREASE RAPIDLY FROM THE W ACROSS
OK/TX...AHEAD OF A SHORTWAVE NOTED ON THE WATER VAPOR LOOP EXTENDING
FROM AZ SE INTO NRN OLD MX. THUS...CONSIDERABLE PACIFIC MOISTURE WILL
OVERSPREAD THE REGION OVERNIGHT...WHICH MAY HELP ACT AS AN INSULATOR
TO HOLD TEMPS IN CHECK. LOW LEVEL MOISTURE RETURN IS CURRENTLY
UNDERWAY THIS EVENING ALONG THE TX COASTAL BEND...AND THIS WILL BEGIN
TO SURGE NWD ACROSS CNTRL TX OVERNIGHT ALONG A 35-40KT SSWRLY LLJ THAT
WILL DEVELOP LATE. HOWEVER...THIS LOW CLOUDINESS IS EXPECTED TO NOT
ENTER E TX UNTIL AFTER 12Z SUNDAY...WHERE STRONG ISENTROPIC FORCING
DEVELOPS ALONG THE 290-300K SURFACES TO YIELD WIDELY SCT SHRA
DEVELOPING BY MID MORNING AND SPREADING NE/INCREASING ACROSS NW LA/SW
AR AFTER 18Z AS THE SHORTWAVE TO THE W TRAVERSES OK/CNTRL TX.
HAVE UPDATED THE ZONES THIS EVENING TO BEEF UP SKY CONDITIONS FROM
MOSTLY CLEAR TO CONSIDERABLE/INCREASING HIGH CLOUDINESS...WHICH WILL
THICKEN FROM W TO E OVERNIGHT. DESPITE THE SE RETURN FLOW/CIRRUS
CANOPY...03Z TEMPS HAVE FALLEN TO NEAR/BELOW FORECAST MINS ALREADY
GIVEN THE VERY DRY AIR STILL IN PLACE...AND HAVE LOWERED MIN A CPL.
DEGREES ACROSS THE BOARD BEFORE TEMPS HOLD IN CHECK..ESPECIALLY OVER E
TX SHORTLY AFTER 06Z. ALSO BEEFED UP SKY CONDITIONS SUNDAY AS
CONSIDERABLE STRATOCU CANOPY RAPIDLY SPREADS NE ACROSS E TX/SE OK
SUNDAY MORNING...AND ACROSS N LA/SW AR DURING THE AFTERNOON. CURRENT
HIGH POPS LOOK REASONABLE...ALTHOUGH THIS WILL BE A LOW QPF EVENT
THROUGH EARLY MONDAY GIVEN THE SHALLOW DEPTH OF THE LOW LEVEL MOISTURE
RETURN...AND OVERALL WEAK FORCING.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.AVIATION...
CIRRUS STREAMING OVERHEAD ATTM IN RESPONSE TO SOUTHWEST UPPER LEVEL
FLOW AHEAD OF A WEAK DISTURBANCE ACROSS NORTHWEST MEXICO. TERMINALS
SHOULD REMAIN MOSTLY VFR THROUGH THE NIGHT BUT AFTER MIDNIGHT...LOW
LEVEL MOISTURE WILL RETURN QUICKLY ACROSS SOUTH CENTRAL AND
SOUTHEAST TEXAS. HAVE TEMPO MVFR CEILINGS NEAR AND JUST AFTER
SUNRISE ACROSS NE TX TERMINALS WITH MVFR CEILINGS BECOMING LIKELY
DURING THE AFTERNOON HOURS ACROSS THESE TERMINALS. 4-5KFT MOISTURE
WILL BE MOVING INTO NW LA/SW AR AND NE LA DURING THE AFTERNOON HOURS
AS WELL WITH MVFR CEILINGS LIKELY JUST AFTER 00Z MON. ISENTROPIC
LIFT IS SUCH THAT WE WILL LIKELY SEE SOME SHOWERS DEVELOPING ACROSS
NE TX BY MID/LATE MORNING AND HAVE TEMPO GROUP AT LFK TERMINAL TO
COVER THIS WITH LIGHT RAIN AND SHOWERS BECOMING MORE WIDESPREAD AFTER
00Z MON. /13/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 30 49 39 57 46 / 0 50 60 20 70
MLU 28 51 40 57 45 / 0 30 80 30 60
DEQ 23 46 33 52 38 / 0 40 50 10 30
TXK 32 47 37 55 43 / 0 40 60 10 50
ELD 25 50 38 56 44 / 0 40 80 20 60
TYR 35 46 38 55 46 / 0 50 30 10 60
GGG 33 49 40 57 46 / 0 50 50 10 60
LFK 35 52 43 62 49 / 0 60 50 20 70
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15/13
