Area Forecast Discussion
Issued by NWS Shreveport, LA

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000
FXUS64 KSHV 011741
AFDSHV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
1141 AM CST SUN FEB 1 2015

.DISCUSSION...
A 20-30NM WIDE BAND OF SHOWERS AND ISOLATED THUNDERSTORMS HAS
DEVELOPED ALONG A COLD FRONT...WHICH EXTENDS FROM NEAR LIT...TO
ADF...TO TXK...TO JXI/TYR...TO JUST E OF CRS AND TPL AS OF 17Z.
THIS CONVECTION HAS RESULTED IN 20-25KT WIND GUSTS ACROSS SW AR/NE
TX WITH ITS PASSAGE...ALTHOUGH WEAK CIN CONTRIBUTED BY THE LOW
LEVEL INVERSION NOTED ON THE 12Z KSHV RAOB CONTINUES TO HOLD
ACROSS SW AR/EXTREME NRN LA. FARTHER S...SOME BREAKS IN THE
STRATUS HAS BEEN NOTED...WITH LFK HAVING JUMPED INTO THE MID 70S.
SHOULD SEE SOME WEAK SFC BASED INSTABILITY DEVELOP THIS AFTERNOON
FROM LOWER TOLEDO BEND COUNTRY NE ACROSS NCNTRL LA AS SOME OF
THESE BREAKS MAY EXTEND NE OVER THESE AREAS...WITH CONTINUED
MOISTURE ADVECTION/BNDRY LYR HEATING CONTRIBUTING TO 500-800 J/KG
OF MLCAPE. FRONTAL CONVERGENCE REMAINS STRONG LATE THIS MORNING
WHERE THE CONVECTION IS ONGOING...WITH THE SHORT TERM PROGS
ACTUALLY MAINTAINING THE FRONTAL CONVERGENCE THROUGH THE AFTERNOON
WHERE A LITTLE BETTER INSTABILITY IS EXPECTED. HOWEVER...LAPSE
RATES ALOFT WILL BE QUITE MARGINAL...WITH THE BEST FORCING
EXPECTED TO BE ON THE NRN FRINGE OF THE WEAK INSTABILITY AXIS.
WHILE BRIEF WIND GUSTS TO 30-35KTS WILL BE POSSIBLE WITH THE
STRONGER CONVECTION...HAVE LOW CONFIDENCE IN SVR CONVECTION DEVELOPING
OVER THE AREA THIS AFTERNOON GIVEN THE VERY MARGINAL THERMODYNAMIC
ENVIRONMENT.

HOWEVER...THE FRONT IS MAKING A LITTLE FASTER PROGRESS SE THAN
EARLIER ANTICIPATED...WITH THE LATEST HRRR RUN HANDLING THE
FRONTAL PROGRESSION QUITE WELL. THE 12Z NAM IS ABOUT 3 HOURS
SLOWER...WITH THE GFS POSITION VERY SIMILAR IF NOT A TAD SLOWER
THAN THE HRRR. THUS...THE CONVECTION SHOULD MOVE OUT OF THE REGION
A LITTLE FASTER THAN EXPECTED LATER THIS AFTERNOON.
HOWEVER...THE MSAS ANALYSIS DEPICTS 3-5MB/3 HOUR PRESSURE RISES
ARE NOTED BEHIND THE FRONT FROM N TX INTO CNTRL OK/KS...WITH A
TIGHTENING PRESSURE GRADIENT BEHIND A SFC LOW OVER SW MO. IN
FACT...THE VISIBLE SATELLITE IMAGERY INDICATES NW TO SE STRIATIONS
IN THE STRATOCU FIELD OVER N TX/MUCH OF CNTRL AND ERN
OK...INDICATIVE OF THE STRONGER WINDS NEAR 2.5-3KFT. THESE
STRONGER WINDS SHOULD WORK INTO MCCURTAIN COUNTY OK AND THE WRN
SECTIONS OF E TX THIS AFTERNOON...AND FOR THAT REASON...HAVE
HOISTED A LAKE WIND ADVISORY FOR THESE AREAS THROUGH 10Z MONDAY.
WILL LIKELY HAVE TO EXPAND THE ADVISORY E INTO SW AR/WRN LA
LATER...BUT WILL ADDRESS THAT WITH THE AFTERNOON FORECAST PACKAGE.

HAVE ALSO RAISED TEMPS A FEW DEGREES ACROSS THE WARM SECTOR PER
THE 17Z OBS...WHILE ALSO REFLECTING A TEMP FALL FOR THE AFTERNOON
BEHIND THE FRONT. ALSO ADUSTED POPS AS WELL PER CURRENT RADAR
TRENDS.

ZONE UPDATE/NPW ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.

15

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  65  31  47  28  56 /  90  10   0   0   0
MLU  68  35  45  27  53 /  80  30   0   0   0
DEQ  55  26  45  24  54 /  60  10   0   0   0
TXK  59  29  43  27  54 /  90  10   0   0   0
ELD  62  30  45  25  53 /  90  10   0   0   0
TYR  64  27  45  31  55 /  60  10   0   0   0
GGG  65  29  44  30  55 /  80  10   0   0   0
LFK  75  33  49  30  57 /  60  10   0   0  10

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...LAKE WIND ADVISORY UNTIL 4 AM CST MONDAY FOR THE FOLLOWING
     ZONES: OKZ077.

TX...LAKE WIND ADVISORY UNTIL 4 AM CST MONDAY FOR THE FOLLOWING
     ZONES: TXZ096-108>111-124-125-136-137-149-150.

&&

$$

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