DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0645 PM CST WED FEB 22 2012

VALID 230100Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS FOR PARTS OF THE TN VALLEY AND
SRN APPALACHIANS...

...TN VALLEY...SRN APPALACHIANS...
A MARGINAL/ISOLATED SEVERE RISK SHOULD EXIST WITH ONGOING TSTM
CLUSTERS PROGRESSING EWD FROM THE TN VALLEY. DOWNSTREAM AIR MASS IS
ONLY MINIMALLY UNSTABLE WITH SURFACE DEW POINTS STILL HOLDING IN THE
40S TO MIDDLE 50S. ALTHOUGH AFTERNOON MODEL FORECAST HAVE BEEN
INSISTENT ON SUBSTANTIAL LOW-LEVEL WARM/MOIST ADVECTION
TONIGHT...THEY HAVE BEEN TOO MOIST IN COMPARISON WITH METARS AND 00Z
RAOBS WITH THE RETURN OF THE MODIFIED GULF AIR MASS. FOR
EXAMPLE...00Z JAN RAOB SAMPLED MLCAPE AROUND 500 J/KG WHILE 18Z NAM
FORECAST SOUNDINGS SUGGESTED MLCAPE OF 1500 TO 2000 J/KG SHOULD BE
PRESENT.

NEVERTHELESS...LARGE CYCLIC HODOGRAPHS /AS SAMPLED BY THE 00Z BMX
RAOB/ ARE FORECAST TO STRENGTHEN THIS EVENING...SUPPORTING
WIDESPREAD EFFECTIVE SRH AOA 250 M2/S2. GIVE AMPLE LOW/DEEP-LAYER
SHEAR...ACTIVITY MAY INTENSIFY SOMEWHAT DESPITE THE ONSET OF
NOCTURNAL COOLING. THE RELATIVELY GREATEST SEVERE THREAT SHOULD
EXIST ACROSS PARTS OF NRN AL/GA AND ERN TN INTO PERHAPS THE WRN
CAROLINAS THROUGH LATE EVENING.

...CNTRL/NERN GULF COAST...
HAVE REMOVED SEVERE PROBABILITIES GIVEN MINIMAL INSTABILITY /PER 00Z
TLH AND TBW RAOBS/ INVOF ONGOING ISOLATED TSTMS. AS THE LARGE-SCALE
WARM/MOIST ADVECTION REGIME SHIFTS NEWD AND THE LACK OF INFLUENCE BY
THE WEAK SHORT WAVE IMPULSE OVER THE TN VALLEY...TSTM REDEVELOPMENT
APPEARS UNLIKELY.

..GRAMS.. 02/23/2012