[BNAWX] Severe Storm Outlook Narrative

[EMWIN Server]

ACUS11 KWNS 202312
SWOMCD
SPC MCD 202311
GAZ000-NCZ000-TNZ000-ALZ000-MSZ000-210115-

MESOSCALE DISCUSSION 0590
NWS STORM PREDICTION CENTER NORMAN OK
0611 PM CDT THU APR 20 2006

AREAS AFFECTED...NRN AL AND NRN GA

CONCERNING...SEVERE THUNDERSTORM WATCH 221...225...

VALID 202311Z - 210115Z

THREAT FOR SVR WILL CONTINUE WITH ORGANIZED CLUSTER ACROSS MUCH OF
WW 225 OVER THE NEXT SEVERAL HRS AS IT MOVES INTO THE WRN PORTION OF
THE ATL METRO AREA BETWEEN 00-01Z. FURTHER WEST...SVR THREAT SHOULD
GRADUALLY DIMINISH OVER WW 221 IN THE NEXT 1-3 HRS. THUS A NEW WW TO
REPLACE WW 221 IS NOT LIKELY ATTM...ALTHOUGH LOCAL WFO EXTENSION IS
POSSIBLE.

LATEST SFC ANALYSIS SHOWS A WELL DEFINED COLD POOL HAS DEVELOPED
OVER NERN AL ASSOCIATED WITH SVR TSTM CLUSTER MOVING OUT OF WW 221
INTO WW 225 /NWRN GA/. GIVEN ORGANIZED NATURE OF CONVECTION AND
STEEP LOW LEVEL LAPSE RATES /NOTED ON THE 18Z ATL SOUNDING / DMGG
WINDS MAY BECOME THE GREATER SVR THREAT AS ACTIVITY MOVES TOWARDS
THE ATL METRO AREA. IN THE WAKE OF THIS CLUSTER...SSWLY FLOW OF
10-20 KTS /NOTED ON RECENT BMX VWP DATA/ WAS ORTHOGONAL TO THE
OUTFLOW BOUNDARY OVER CENTRAL/NCENTRAL AL. COMBINED WITH MODERATE
INSTABILITY AND MARGINAL CINH THIS SHOULD SUPPORT A THREAT FOR
REDEVELOPMENT OF TSTMS TO THE EAST OF THE OUTFLOW BOUNDARY OVER
NCENTRAL/NERN AL FOR THE NEXT COUPLE OF HRS. GRADUALLY DIMINISHING
INSTABILITY AFTER 00Z /WITH LOSS OF HEATING / COMBINED WITH
DISPLACEMENT OF CONVECTION FURTHER AWAY FROM THE WWD MOVING OUTFLOW
BOUNDARY /NOTED ON BMX RADAR/ WILL LIKELY LEAD TO A DIMINISHING SVR
THREAT WITH TIME. THE DIMINISHING INSTABILITY SHOULD ALSO LEAD TO A
GRADUAL DEMISE OF ISOLATED SVR STORM NEAR THE AL/MS BORDER...BUT NOT
BEFORE THE PASSAGE OF THE WWD MOVING OUTFLOW BOUNDARY INTERACTS WITH
THIS STORM. LOCALLY BACKED LOW LEVEL FLOW JUST AHEAD OF THE BOUNDARY
MAY AID IN A BRIEF LOCALIZED TORNADO THREAT WITH THIS STORM AROUND
00Z.

..CROSBIE.. 04/20/2006

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...GSP...MRX...FFC...BMX...HUN...MEG...JAN...

35158506 34678822 33368850 33298603 33068613 33008428
34998343 34988503

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