Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS03 KWNS 150723
SWODY3
SPC AC 150722

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0222 AM CDT SAT MAR 15 2014

VALID 171200Z - 181200Z

...NO SVR TSTM AREAS FORECAST...

...FLORIDA...
AN UPPER-LEVEL LOW NEAR THE SABINE RIVER AT 12Z MONDAY IS FORECAST
TO MOVE INTO THE LOWER MS VALLEY MONDAY AFTERNOON. AT THE SFC...A
LOW IS FORECAST TO MOVE ACROSS THE ERN GULF OF MEXICO MONDAY MORNING
WITH A COLD FRONT APPROACHING THE WEST COAST OF FL BY AFTERNOON. A
LINE OF THUNDERSTORMS SHOULD BE ONGOING AHEAD OF THE FRONT ALONG A
CORRIDOR OF ENHANCED LOW-LEVEL CONVERGENCE. ALTHOUGH SOME
UNCERTAINTY EXISTS CONCERNING TIMING...THE CURRENT THINKING IS THAT
THE LINE WILL MOVE ONTO THE WEST COAST OF FL DURING THE AFTERNOON.

A VERY MOIST AIRMASS SHOULD BE IN PLACE AHEAD OF THE FRONT WITH SFC
DEWPOINTS EXPECTED TO BE IN THE 65 TO 70 F RANGE. THIS COMBINED WITH
SFC HEATING...SHOULD ALLOW MODERATE INSTABILITY TO DEVELOP BY MIDDAY
ON THE FL WEST COAST. THE NAM FORECAST SOUNDING FOR TAMPA BAY AT 21Z
SHOWS MLCAPE AROUND 1000 J/KG WITH 60 KT OF 0-6 KM SHEAR. THIS
ENVIRONMENT ALONG WITH 50 KT OF FLOW JUST ABOVE THE SFC SHOULD
SUPPORT ISOLATED DAMAGING WIND GUSTS ASSOCIATED WITH THE LINE. AT
THIS POINT...THE MAGNITUDE OF THE SEVERE THREAT IS THE MAIN
QUESTION. THE ECMWF...NAM AND GFS SOLUTIONS KEEP THE STRONGEST
LARGE-SCALE ASCENT WELL TO THE WEST OF THE FRONT SUGGESTING THE MAIN
DRIVING FACTOR WILL BE WARM ADVECTION AND LOW-LEVEL CONVERGENCE. FOR
THIS REASON...WILL KEEP THE SEVERE PROBABILITIES AT 5 PERCENT FOR
NOW.

..BROYLES.. 03/15/2014
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