FXUS64 KSHV 041044
AFDSHV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
444 AM CST FRI DEC 4 2009
.DISCUSSION...
OVERNIGHT CLOUDINESS HAS HAD AN ADVERSE IMPACT ON THE ANTICIPATED
FREEZE CONDITIONS FOR THIS MORNING. TEMPERATURES ACROSS EAST TEXAS
AND NORTHERN LOUISIANA HAVE HELD IN THE MID TO UPPER 30S FOR THE
PAST COUPLE OF HOURS. ACCORDINGLY...WENT AHEAD AND CANCELLED THE
FREEZE WARNING EARLY.
MUCH DRIER AIR CONTINUES TO SURGE SOUTH ACROSS THE
FOUR STATE REGION THIS MORNING WITH DEWPOINTS IN THE MID TEENS
ACROSS SOUTHEAST OKLAHOMA AND SOUTHERN ARKANSAS AND MID 20S TO
AROUND 30 FARTHER SOUTH. WITH SUCH DRY AIR AT THE LOWER
LEVELS...INITIAL PRECIPITATION LATER TODAY WILL REQUIRE SUFFICIENT
EVAPORATIVE CONDITIONING BEFORE REACHING THE SURFACE.
NOT MUCH CHANGE FROM PREVIOUS REASONING REGARDING THE UPCOMING
SNOW EVENT LATER TODAY ACROSS EAST TEXAS AND WEST CENTRAL LOUISIANA.
TEMPERATURES ARE FORECAST TO STEADILY FALL THROUGH THE AFTERNOON
AS PRECIPITATION BEGINS TO MODERATE THE ATMOSPHERE THROUGH
EVAPORATIVE COOLING. INITIAL RAINFALL IS FORECAST TO TRANSITION
INTO SNOW WITH THE HEAVIEST ACCUMULATION EXPECTED ALONG A LINE
FROM NACOGDOCHES TEXAS...THROUGH MANY LOUISIANA...AND EASTWARD TO
JENA LOUISIANA. THIS EVENT IS EXPECTED TO BE SHORT LIVED RANGING FROM MID
AFTERNOON THROUGH MIDNIGHT TONIGHT WITH SNOW ACCUMULATIONS BETWEEN
1 TO 2 INCHES ACROSS THE SOUTHERN COUNTIES AND PARISHES OF THE
COUNTY WARNING AREA.
LINGERING SNOW MAY LEAD TO ICING PROBLEMS ACROSS BRIDGES AND
OVERPASSES DURING THE OVERNIGHT HOURS AS TEMPERATURES ARE PR0GGED
TO FALL INTO THE MID 20S ACROSS SNOW COVERED AREAS. ALONG WITH
THESE PRECAUTIONS...THE ENTIRE FOUR STATE REGION SHOULD PREPARE
FOR FREEZING CONDITIONS AS LOWS ARE ALSO PROGGED TO FALL INTO THE
TEENS ACROSS SOUTHEAST OKLAHOMA AND PORTIONS OF ARKANSAS.
A SERIES OF DISTURBANCES WILL MOVE THROUGH THE REGION THROUGH THE
REMAINDER OF THE FORECAST PERIOD...PROVIDING A WET FORECAST FOR
THE UPCOMING WORK WEEK. THE FIRST OF THESE WILL PUSH ACROSS THE
REGION LATE SUNDAY NIGHT INTO MONDAY MORNING FOLLOWED BY A MORE
VIGOROUS SYSTEM TUESDAY NIGHT INTO WEDNESDAY./05/
&&
.AVIATION...
DESPITE THE OVC SKIES...FLIGHT CATEGORIES REMAINED VFR ACROSS AREA
TERMINALS EARLY THIS MORNING. AREA RADARS CONTINUE TO SHOW SOME
LIGHT RETURNS ACROSS NE TX/S AR...BUT NO PRECIPITATION IS REACHING
THE GROUND AS OF YET. THESE RETURNS WERE MORE THAN LIKELY SOME LOW
AC/HIGH SC. IN GENERAL...NO MAJOR CHANGES ARE EXPECTED OVER
AIRPORTS ACROSS THE AREA THROUGH AT LEAST 04/1600 UTC OR SO.
A RATHER DEEP UPPER-LEVEL TROUGH IS FORECAST TO MOVE ACROSS THE
FORECAST AREA OVER THE NEXT 24 HOURS. AS THE MORNING PROGRESSES...
WE EXPECT THE ATMOSPHERIC BOUNDARY LAYER TO CONTINUE SATURATING FROM
THE TOP DOWN. WITH COLD TEMPERATURES AND A LITTLE EVAPORATIVE
COOLING ANTICIPATED...RATHER EARLY SEASON SN WILL BE POSSIBLE.
WHERE -- THE GREATEST RISK OF SEEING SN ACROSS OUR AREA WILL LIKELY
BE ALONG AND S OF A KJSO-KTVR AXIS...IN A REGION WITH SLIGHTLY
DEEPER MOISTURE. -RASN OR --SN MIGHT BE SEEN AS FAR N AS THE IH-20
CORRIDOR...BUT IS MORE QUESTIONABLE HERE.
WHEN -- CURRENT TIMING TRENDS IN THE ONGOING TAF PACKAGE LOOK GOOD.
-SN MAY MOVE INTO KLFK BETWEEN 04/1800-2100 UTC AND CONTINUE OFF AND
ON THROUGH MUCH OF THE EVENING. MAY SEE SOME -SN AT KMLU BETWEEN
05/0000-0300 UTC...BUT ANY MENTION HERE WILL BE BASED ON A
LAST-MINUTE JUDGEMENT CALL. I PLAN ON KEEPING OTHER TERMINALS DRY
FOR THE TIME BEING...ALTHOUGH -RASN/--SN CANNOT BE DISCOUNTED
/ESPECIALLY/ TOWARD SUNSET.
PRECIPITATION SHOULD START TAPERING FROM THE S/W AFTER 05/0300
UTC...WITH GRADUALLY INCREASING CIGS AFTER 05/0600 UTC. /D. BUTTS/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 41 24 49 31 51 / 30 20 0 10 30
MLU 43 26 48 27 51 / 30 40 0 10 30
DEQ 42 18 50 25 48 / 10 10 0 10 30
TXK 42 23 48 32 46 / 20 10 0 10 30
ELD 41 20 50 27 50 / 20 20 0 10 30
TYR 39 23 49 34 48 / 30 20 0 10 30
GGG 39 22 49 34 49 / 30 20 0 10 30
LFK 39 23 48 33 53 / 60 40 0 10 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST
TONIGHT FOR THE FOLLOWING ZONES: LAZ018>022.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: LAZ017.
OK...NONE.
TX...WINTER WEATHER ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: TXZ149-152-153-165>167.
&&
$$
05/D. BUTTS/
