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000
FXUS64 KSHV 051818
AFDSHV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
1218 PM CST THU DEC 5 2013

.UPDATE...
PULLED BACK ICE STORM WARNING START TIME TO MIDNIGHT TONIGHT.

&&

.DISCUSSION...
ARCTIC COLD FRONT IS ON TRACK...BUT STILL NOT OVER OUR SE CWA.
AIR TEMPS ARE FALLING IN THE 30 AND 40S FOR MANY OVER NW HALF WITH
THE FREEZING LINE AT PARIS TX...SNAKING...INTO THE OUACHITA/S UP TO
FORT SMITH. DRIER AND COLDER AIR IS PUSHING IN WITH GUSTS OVER E
OK TOWARD OUR AREA AND FOR THAT REASON HAVE PULLED BACK START
TIME. IN FACT...SOME OF THE WARNING AREA MAY BEGIN TO SEE VERY
LIGHT ACCUMULATION SHORTLY AFTER SUNSET...BUT TOO DIFFICULT TO
SEPARATE OUT A PORTION FOR THE EVENING WORDING WISE FOR ADVISORY
CRITERIA.

THE GFS AND NAM ARE SIMILAR IN REALLY BEEFING UP THE AMOUNTS OF
PRECIP WITH THE WATER VAPOR SHOWING A GOOD PUSH OF DIVERGENCE
ALOFT NOW OVER BAJA AND NORTHWESTERN MEXICO. QPF AMOUNTS WILL BE
HEARTY ALONG I-30 CORRIDOR AND THE ICE STORM WARNING AREA. THE
GOOD NEWS IS THAT THIS PUSH WILL BETTER SEPARATE THE TWO EVENTS
AND MAKE FOR A LITTLE BETTER SATURDAY...ALBEIT STILL VERY
COLD...BUT SOME TOKEN SUNSHINE MAY BE SEEN WITH EXITING DIVERGENCE.

THE NEXT OVERRUNNING FOR THE WEEKEND IS PUSHING UNDER THE BAJA LOW
FROM THE TROPICAL E PAC. SO NO CHANGES BEYOND NOON TOMORROW AT
THIS TIME IN DEALING WITH THE CURRENT UNFOLDING EVENTS FOR SHORT
TERM. THE BACK EDGE OF THE THIS WILL PUSH OVER THE AREA DURING THE
AFTERNOON ON FRIDAY WITH SLIGHTLY FASTER TIMING ON NAM...AND NEW GFS
IS NOT FAR BEHIND. WE ARE CURIOUS TO SEE NEW EURO ALONG SIDE GFS
FOR THE WEEKEND. HOWEVER...THE NEW 12Z GFS HAS CONTINUED IT/S
TREND WITH ONSET FOR THE NUMBER TWO EVENT INITIATION FOR A TINY BIT
LATER ON SATURDAY AFTERNOON AND EVENING. IT STILL LOOKS HEARTY
OVERNIGHT AND INTO SUNDAY WITH ANOTHER ICE STORM WATCH DEEPER INTO
OUR CWA TO BE ISSUED FOR THAT LATER IN THE SHORT TERM. /24/


.AVIATION...
VERY STG COLD FRONT HAS MOVD ACROSS ALL TERMINAL LOCATIONS...AND
QUICKLY APPROACHING KMLU TERMINAL ATTM. SCATTERED BRIEF SHOWERS
AHEAD AND ALONG FRONT. N-NW WINDS AROUND 15 KTS MOST OF DAY...AND
ONLY SUBSIDING TO AROUND 10 KTS OVERNIGHT. COLD AIRMASS VERY
SHALLOW...THUS WINDS ABOVE FIRST 1000 OR 2000 FEET WILL REMAIN FROM
SW TODAY. POSTFRONTAL CIGS IN MVFR CAT...AND LOWER IFR CIGS AND
LOWER VSBYS IN SHOWERS WITH FROPA. CIGS WILL ALSO GRADUALLY LOWER
INTO IFR CAT AFTER 06/00Z WITH INCREASING PRECIP LOWERING THE DECKS.
STG WARM NOSE IN SW WINDS ABOVE SFC WILL INSURE THAT RA AND FZRA
ONLY PRECIP TYPES...DEPENDING ON LOCATION OF SFC FRZG LINE.
HOWEVER...INITIAL WARM GROUND AND SFC CONDITIONS MAY SLOW ONSET OF
ICE ACCUMULATIONS ON EXPOSED SURFACES. KTXK...KTYR...AND KGGG MAY
TRANSITION TO FZRA AFTER 06/09Z DEPENDING ON EXACT LOCATION OF FRZG
LINE./VII/


&&

.PREV DISCUSSION... /ISSUED 437 AM CST THU DEC 5 2013/

DISCUSSION...
COLD FRONT ENTERED THE CWA OVERNIGHT AND HAS REACHED A ARKADELPHIA
ARKANSAS TO JACKSONVILLE TEXAS LINE AS OF 10Z. STILL NO
PRECIPITATION WITH THE SYSTEM AS THE UPPER TROUGH JUST REACHING
THE CENTRAL ROCKIES. THE TROUGH SHOULD DIG INTO THE SOUTHERN
ROCKIES BY 00Z FRIDAY...AND THIS WILL GET THE MOISTURE TRAIN
STARTED IN THE SOUTHWEST FLOW. LOOK FOR SCATTERED SHOWERS TO
DEVELOP BY MIDDAY...BUT RAIN SHOULD INCREASE IN ERNEST ACROSS THE
CWA THIS EVENING. MUCH COLDER TEMPERATURES AND GUSTY NORTHWEST
WIND WILL FOLLOW THE FRONT TODAY...BECOMING ENTRENCHED OVER THE
REGION THROUGH THE REMAINDER OF THE SEVEN DAY FORECAST. AS
TEMPERATURES FALL...RAIN WILL BEGIN TO CHANGE OVER TO FREEZING
RAIN. THIS WILL HAPPEN ALONG THE NORTHERN BORDER OF THE CWA LATER
THIS AFTERNOON. HOWEVER...DUE TO EXPECTED COLD AIR DAMMING IN
SOUTHEAST OKLAHOMA...THINK MOST OF AREA WILL REMAIN ABOVE FREEZING
UNTIL LATE TONIGHT. ALL MODELS FOLLOW THIS SCENARIO...SO HAVE
BACKED OF THE ONSET OF THE ICE STORM WARNING UNTIL 4 AM TONIGHT.
THE AREA EXPECTED TO FALL BELOW FREEZING WILL INCLUDE SOUTHEAST
OKLAHOMA... ADJACENT SOUTHWEST ARKANSAS AND NORTHEAST TEXAS. AT
THIS TIME IT APPEARS THAT TEMPERATURES IN THE ICE STORM WARNING
AREA WILL BECOME LOCKED NEAR OR JUST ABOVE THE FREEZING MARK
THROUGH MUCH OF FRIDAY...THUS ICE ACCUMULATIONS MAY NOT BE THAT
SIGNIFICANT. HOWEVER ONE OR TWO DEGREES WILL DETERMINE THIS...SO
WILL CONTINUE WITH THE QUARTER INCH ACCUMULATIONS. THE REMAINDER
OF THE CWA WILL EXPERIENCE A COLD RAIN FOR MOST OF TONIGHT AND
FRIDAY. THE RAIN AREA WILL SHIFT EAST FRIDAY NIGHT...BUT FALLING
TEMPERATURES COULD LEAD TO SOME MORE FREEZING RAIN ACROSS NORTH
LOUISIANA AND SOUTH CENTRAL ARKANSAS.

FOR SATURDAY INTO SUNDAY...THE MAIN UPPER TROUGH MOVES VERY LITTLE...
ALLOWING A RETURN OF RAIN TO THE ENTIRE AREA ON SATURDAY AS A
SHORT WAVE MOVES THROUGH THE SOUTHWEST FLOW. FREEZING TEMPERATURES
WILL BE IN PLACE SATURDAY MORNING WHEN THE RAIN PICKS BACK UP...SO
MUCH OF THE CWA HAS A GOOD CHANCE FOR ICE ACCUMULATIONS SATURDAY
INTO SATURDAY NIGHT AND SUNDAY. MODELS HAVE BACKED OFF ON THE
AMOUNT OF PRECIPITATION FOR THE WEEKEND...SO THE RAIN AMOUNTS
SHOULD GENERALLY BE LESS THAN ONE QUARTER INCH. THE TROUGH FINALLY
KICKS EAST ON MONDAY...LEAVING A COLD NORTHWEST FLOW AND DRY
WEATHER THROUGH MID WEEK.

AVIATION...
COLD FRONT LOCATED ROUGHLY ALONG A KTYR/KTXK/KADF LINE WILL MAKE ITS
WAY SLOWLY ACROSS THE REGION TODAY...WITH MVFR/IFR CIGS/VSBYS TO
PREVAIL FOR MUCH OF THE TAF PD. LIGHT RAIN IS EXPECTED TO DEVELOP
THIS MORNING...MAINLY BEHIND THE FRONT...THEN INCREASE BY TONIGHT
AND CONTINUE THROUGH FRIDAY MORNING AND BEYOND. THE VERY COLD
AIRMASS THAT WILL FILTER INTO THE REGION TODAY/TONIGHT MAY BRING
-FZRA...MAINLY FOR AREAS ALONG AND N OF A KTYR/KTXK LINE TOWARDS THE
END OF THE PD. OTHERWISE...EXPECT GUSTY NWLY WINDS AFTER FROPA
AREAWIDE...TURING MORE NELY BY FRIDAY MORNING. /12/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  58  36  37  33  34 /  50 100 100  20  50
MLU  73  39  40  32  35 /  50  80 100  40  50
DEQ  44  30  34  20  30 /  80 100 100  10  20
TXK  50  31  33  22  28 /  70 100 100  10  40
ELD  66  35  36  28  32 /  70 100 100  20  40
TYR  44  32  33  28  31 /  50 100 100  10  50
GGG  48  34  35  30  31 /  50 100 100  10  50
LFK  68  38  42  35  36 /  40  70 100  30  50

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...ICE STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM CST FRIDAY FOR
     THE FOLLOWING ZONES: ARZ050-051-059>061-070-071.

LA...NONE.
OK...ICE STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM CST FRIDAY FOR
     THE FOLLOWING ZONES: OKZ077.

TX...ICE STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM CST FRIDAY FOR
     THE FOLLOWING ZONES: TXZ096-097-108>112-124-125-136.

&&

$$

24/07