Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS01 KWNS 011958
SWODY1
SPC AC 011957

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0157 PM CST SUN FEB 01 2015

VALID 012000Z - 021200Z

...THERE IS A MRGL RISK OF SVR TSTMS FROM SE TX TO CENTRAL MS/W
CENTRAL AL...

...SUMMARY...
A FEW MARGINALLY SEVERE THUNDERSTORMS WITH STRONG WIND GUSTS MAY
OCCUR THIS AFTERNOON AND EARLY EVENING FROM PORTIONS OF SOUTHEAST
TEXAS TO THE LOWER MISSISSIPPI VALLEY REGION.

...20Z UPDATE...
NO CHANGES TO FORECAST REASONING...ALTHOUGH SPATIAL ADJUSTMENTS WERE
MADE TO PARTS OF CENTRAL/EAST TX IN ACCORDANCE WITH THE PROGRESSION
OF THE COLD FRONT.

..GUYER.. 02/01/2015

.PREV DISCUSSION... /ISSUED 1026 AM CST SUN FEB 01 2015/

...E TX TO THE LOWER MS VALLEY THROUGH THIS EVENING...
A MIDLEVEL SHORTWAVE TROUGH OVER THE CENTRAL PLAINS WILL PROGRESS
EWD TO THE OH VALLEY AND APPALACHIANS BY MONDAY MORNING.  A SURFACE
CYCLONE WILL PRECEDE THE MIDLEVEL WAVE FROM NRN MO THIS MORNING TO
CENTRAL PA BY MONDAY MORNING...AS A TRAILING COLD FRONT TRANSLATES
SEWD ACROSS TX AND THE LOWER MS/TN VALLEY REGION.

CONVECTION HAS BEEN LIMITED WITH THIS SYSTEM THUS FAR...WITH ONLY
ISOLATED LIGHTNING FLASHES OBSERVED OVER NE TX.  THE COMBINATION OF
BOUNDARY LAYER DEWPOINTS SLOWLY RISING INTO THE LOWER 60S AND
DAYTIME HEATING IN CLOUD BREAKS WILL RESULT IN SOME DESTABILIZATION
IN ADVANCE OF THE COLD FRONT BY THIS AFTERNOON /SBCAPE VALUES
APPROACHING 500 J PER KG/.  THOUGH SHOWERS AND ISOLATED
THUNDERSTORMS MAY FORM LATER THIS AFTERNOON WITHIN THE WARM
SECTOR...THE PRIMARY FOCUS FOR CONVECTIVE DEVELOPMENT WILL BE THE
BAND OF LOW-LEVEL ASCENT ALONG THE COLD FRONT WHEN BUOYANCY IS
MAXIMIZED BY LATER THIS AFTERNOON.

THE FRONTAL CONVECTION WILL STRENGTHEN GRADUALLY THROUGH THE
AFTERNOON...WITH THE POTENTIAL FOR A MARGINAL SEVERE STORM RISK BY
MID-LATE AFTERNOON FROM SE TX TO CENTRAL MS.  BUOYANCY WILL BE
RELATIVELY WEAK AND WARM SECTOR WIND PROFILES WILL BECOME LARGELY
UNIDIRECTIONAL WITH STRAIGHT HODOGRAPHS...AS THE SURFACE CYCLONE
DEVELOPS WELL N/NE OF THE LOWER MS VALLEY.  THUS...ISOLATED
STRONG/DAMAGING WIND GUSTS WITH EMBEDDED CELLS OR SHORT LINE
SEGMENTS WILL BE THE MAIN CONCERN THIS AFTERNOON/EVENING...PRIOR TO
BUOYANCY DIMINISHING BY EARLY TONIGHT.




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