Area Forecast Discussion
Issued by NWS Shreveport, LA

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000
FXUS64 KSHV 261745
AFDSHV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
1245 PM CDT TUE MAY 26 2015

.AVIATION...
EXPECT VFR WEATHER TO BEGIN THE 26/18Z TAF ISSUE. CANNOT RULE OUT
CONVECTION TOTALLY THIS AFTERNOON...BUT COVERAGE SHOULD BE
ISOLATED AND SHOULD EASILY BE AVOIDED. EXPECT MVFR CIGS TO RETURN
AFTER 08Z TONIGHT ACROSS THE AREA. MIXING WILL ALLOW FOR THESE
CIGS TO LIFT TO VFR BY 27/16Z.  /14/

&&

.PREV DISCUSSION... /ISSUED 1116 AM CDT TUE MAY 26 2015/

DISCUSSION...
HAVE UPDATED THE ZONES TO REMOVE THE HIGHER RAIN CHANCES OVER THE
SOUTHERN ZONES FOR THE REST OF THE MORNING AND SCALED BACK FOR THE
AFTERNOON WITH JUST THE MORE SOUTHERN WITH A LOWER CHANCE
CATEGORY. HRRR MODEL INDICATED DEVELOPMENT OVER PARTS OF DEEP
EAST TEXAS AND EAST ACROSS ADJACENT NORTHWEST AND NORTH CENTRAL
LOUISIANA DURING THE AFTERNOON. A SURFACE RIDGE OF HIGH PRESSURE
EXTENDED WEST INTO THE FORECAST AREA WITH A SOUTHWEST FLOW ALOFT
WITH A SERIES OF SMALLER SCALE DISTURBANCES MOVING THROUGH THE
FLOW AROUND A BROAD TROUGH ACROSS TEXAS. /06/

PREV DISCUSSION... /ISSUED 417 AM CDT TUE MAY 26 2015/

DISCUSSION...
AFTER WIDESPREAD SEVERE THUNDERSTORMS AFFECTED THE REGION DURING
THE AFTERNOON AND EVENING HOURS MONDAY...MUCH CALMER CONDITIONS
ARE EXPECTED IN THE SHORT TERM...WITH THE AIR MASS HAVING BEEN
STABILIZED AREAWIDE. THE MORNING IR SATELLITE IMAGERY CONTINUES TO
SHOW A WARMING OF THE CLOUD TOPS ACROSS THE REGION...WITH THE POST
SQUALL LINE RAINS DIMINISHING IN INTENSITY ATTM. WITH THE PRIMARY
SHORTWAVE RESPONSIBLE FOR THE MONDAY AFTERNOON/EVENING CONVECTION
HAVING ALREADY LIFTED TO THE NE OVER SE KS/NE OK /PER WATER VAPOR
IMAGERY/...THE THREAT FOR HEAVY RAINFALL IS ENDING...AND WILL BE
CANCELLING THE FLASH FLOOD WATCH FOR THE CWA WITH THE MORNING
FORECAST. THE GFS/HRRR HAVE INITIALIZED WELL THIS MORNING WITH
THE ONGOING CONVECTION...WITH IT CLEARING THE SRN/ERN SECTIONS OF
NCNTRL LA BETWEEN 12-15Z...AND THUS HAVE TAPERED POPS BACK FARTHER
W...EVEN DROPPING POPS THIS MORNING OVER MUCH OF SW AR/SE OK/NE
TX. STILL CAN/T RULE OUT ADDITIONAL SCT REDEVELOPMENT THIS
AFTERNOON MAINLY FROM LOWER TOLEDO BEND INTO NCNTRL LA...WITH
ISOLATED CONVECTION AT BEST POSSIBLE ELSEWHERE. TEMPS SHOULD AGAIN
CLIMB BACK TO NEAR CLIMO OVER MUCH OF THE REGION THIS AFTERNOON.

SW FLOW ALOFT WILL PERSIST OVER THE SRN PLAINS/LOWER MS VALLEY
TODAY AND TONIGHT...AS BROAD TROUGHING REMAINS OVER THE CNTRL AND
SRN PLAINS. THE SHORT TERM PROGS ARE KEYING ON ANOTHER SHORTWAVE
IN THIS FLOW TRAVERSING THE RED RIVER VALLEY THIS EVENING/OVERNIGHT...
WHICH MAY IGNITE SCT CONVECTION ALONG/JUST E OF THE W TX DRYLINE.
THUS...SCT CONVECTION MAY SHIFT E ALONG THE RED RIVER VALLEY
POSSIBLY AFFECTING SE OK/ADJACENT SW AR/EXTREME NE TX LATE
TONIGHT. HAVE MAINTAINED MID CHANCE POPS FOR THESE AREAS...AND
LOWERED POPS TO SLIGHT CHANCE FARTHER SE OVER DEEP E TX/SRN
SECTIONS OF NCNTRL LA FARTHER REMOVED FROM THIS SHORTWAVE.
MESOSCALE BNDRYS FROM THE OVERNIGHT CONVECTION MAY HELP INITIATE
REDEVELOPMENT FARTHER E OVER MUCH OF THE REGION WEDNESDAY...AS
DAYTIME HEATING CONTRIBUTES TO INCREASED INSTABILITY AS THE
SHORTWAVE TRAVERSES THE REGION. THIS CONVECTION SHOULD DIMINISH
TUESDAY EVENING WITH THE LOSS OF HEATING...WITH THE SHORT TERM
PROGS SUGGESTING THAT DIRTY RIDGING ALOFT WILL BUILD NE FROM E TX
INTO THE MID-MS VALLEY AHEAD OF UPPER TROUGHING THAT WILL DRIFT E
INTO THE ROCKIES.

THE GLOBAL MODELS SUGGEST THAT SCT CONVECTION WILL DEVELOP
BENEATH THIS DIRTY RIDGE WITH HEATING THURSDAY...BEFORE
DIMINISHING THURSDAY EVENING. HAVE MAINTAINED MID CHANCE POPS
AREAWIDE...WITH A MORE UNSETTLED PATTERN TAKING SHAPE FRIDAY
THROUGH THE UPCOMING WEEKEND AS THE UPPER TROUGH TO OUR W SETTLES
FARTHER S ACROSS THE SRN PLAINS. CONFIDENCE REMAINS LOW AS TO THE
EXTENT OF CONVECTION EACH DAY...ALTHOUGH FEEL THAT NE TX/SW AR/SE
OK MAY SEE THE CONVECTION INITIALLY...WITH THE CONVECTION POSSIBLY
SPREADING FARTHER ESE EACH AFTERNOON IN RESPONSE TO MESOSCALE
INTERACTIONS. THIS TROUGH MAY USHER A WEAK COOL FRONT S INTO THE
REGION BY SUNDAY...POSSIBLY WASHING OUT SOMEWHERE OVER E TX/N LA.
THUS...SCT CONVECTION WILL REMAIN POSSIBLE EACH DAY BEFORE THE
UPPER AIR PATTERN FINALLY TRIES TO CALM DOWN AS RIDGING ALOFT
BEGINS TO BUILD OVER MUCH OF THE PLAINS BY EARLY NEXT WEEK.

PRELIMS TO FOLLOW BELOW...

15

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  71  86  70  86 /  30  40  20  40
MLU  70  86  70  86 /  20  40  30  40
DEQ  67  84  69  84 /  40  40  20  40
TXK  69  85  69  86 /  30  40  20  40
ELD  69  85  69  86 /  30  40  30  40
TYR  72  86  71  86 /  30  40  20  40
GGG  72  86  71  86 /  30  40  20  40
LFK  73  87  72  86 /  20  40  20  40

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&

$$


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