Mesoscale Discussion 396

Issued

Mar 31, 2012, 6:18 AM CDT (11:18 UTC)

Expired

Mar 31, 2012, 8:15 AM CDT

In force

117 min

Issued by

the Storm Prediction Center

Counties Bay County, FL, Calhoun County, FL, Dixie County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Jackson County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Suwannee County, FL, Taylor County, FL, Wakulla County, FL, Brooks County, GA, Decatur County, GA, Grady County, GA, Seminole County, GA, Thomas County, GA

The Tallahassee radar (KTLH), 50 km from the middle of the area, began a volume at 11:18 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

732 
ACUS11 KWNS 311118
SWOMCD
SPC MCD 311118 COR
FLZ000-GAZ000-311315-

MESOSCALE DISCUSSION 0396
NWS STORM PREDICTION CENTER NORMAN OK
0618 AM CDT SAT MAR 31 2012

AREAS AFFECTED...PORTIONS COASTAL FL PANHANDLE...NWRN FL...SWRN GA.

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 311118Z - 311315Z

CORRECTED FOR GEOGRAPHIC HEADER

SMALL QUASI-LINEAR MCS WITH OCNL BOW/LEWP FEATURES MAY PRODUCE
STG/ISOLATED DAMAGING WIND FROM ERN BAY COUNTY EWD ACROSS COASTAL
AREAS S TLH.  TORNADO POTENTIAL...IF ANY...WOULD BE VERY
BRIEF/CONDITIONAL ON STORM-SCALE EFFECTS....SUCH AS TRANSIENT
MISOCIRCULATIONS.  LESS-ORGANIZED/E-W CONVECTIVE BAND IS
STRENGTHENING NEAR JUNCTION OF FL-AL/GA BORDERS AND MAY GROW UPSCALE
AS WELL.  SVR THREAT APPEARS TOO MRGL/DISORGANIZED FOR WW.

AS OF 1015Z...IR AND ANIMATED COMPOSITE-REFLECTIVITY IMAGERY
INDICATE WELL-DEFINED MESOSCALE CONVECTIVE VORTICITY FIELD -- LEFT
OVER FROM CONVECTION OVER DEEP S TX AND NERN MEX ABOUT 36 HOURS AGO
-- CENTERED ABOUT 45 S MOB OVER GULF.  THIS FEATURE WAS MOVING EWD
TO ENEWD ABOUT 25 KT...OFFERING LARGE-SCALE ASCENT IN CONVECTIVE
ENVIRONMENT.  ASSOCIATED MODULATION OF MIDLEVEL WINDS TO ITS E
YIELDED BACKING WITH HEIGHT IN 1-3 KM AGL LAYER...IN PRE-STORM VWP
FROM EGLIN AFB.  THIS PROFILE IS DEPICTED WELL ON PROXIMAL RUC FCST
SOUNDINGS FARTHER E ACROSS AREAS NEAR AND INLAND FROM AAF OVER NEXT
2-3 HOURS...SUPPORTING PROBABILITY OF CONTINUED QUASI-LINEAR/MESSY
CONVECTIVE MODES WITH COASTAL COMPLEX.  WHEN FACTORING IN VEERED SFC
FLOW...DEEP-LAYER SHEAR IN THIS EWD-SHIFTING REGIME WILL REMAIN
MODEST -- E.G. EFFECTIVE SHEAR MAGNITUDE 25-35 KT.  STILL...FORWARD
PROPAGATION AND RESULTANT FORCED ASCENT OF FAVORABLY MOIST AIR MASS
NEAR COAST SHOULD SUPPORT PERSISTENCE OF THIS COMPLEX EWD ACROSS
LOWER APALACHICOLA RIVER AREA TOWARD NRN SHORE OF APALACHEE BAY.

FCST SOUNDINGS SUGGEST SFC-BASED EFFECTIVE INFLOW PARCELS WITH
MLCAPE RANGING FROM AROUND 1000 J/KG ALONG COAST TO 500 J/KG N OF
I-10.  BUOYANCY AND CINH BECOME DECIDEDLY UNFAVORABLE OVER NRN
PENINSULA...DUE TO LOWER-THETAE BOUNDARY-LAYER TRAJECTORIES.  SWLY
SFC WINDS MAY ADVECT FAVORABLE THETAE INLAND W OF I-75 BEFORE
CONVECTION REACHES AREA.

..EDWARDS.. 03/31/2012

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

ATTN...WFO...TBW...JAX...TAE...

LAT...LON   30228588 30568560 30948547 31038413 30788330 30208292
            29728284 29468295 29348314 29448326 29448331 29518339
            29688340 29728360 29818358 29918366 30108405 30068431
            29908433 29918450 29568497 29668521 29658536 29888544
            29728530 29898535 30118566 30228593 30228588

Mesoscale Discussions in Florida, 2012Mesoscale Discussions in Georgia, 2012Every mesoscale discussion in 2012

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.