SPC AC 290058
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK
0758 PM CDT SUN MAR 28 2010
VALID 290100Z - 291200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF GA...SC...NC
AND FAR SRN VA...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SRN FL...
....PIEDMONT...
THE LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL TROUGH OVER THE
OH AND TN VALLEYS WITH NUMEROUS THUNDERSTORMS ONGOING JUST AHEAD OF
A DRY SLOT FROM CNTRL GA EXTENDING NEWD INTO CNTRL NC. THE STORMS
ARE ALIGNED ALONG THE AXIS OF THE LOW-LEVEL JET WHICH WILL GRADUALLY
SHIFT EWD ACROSS THE CAROLINAS THIS EVENING. THE LATEST WSR-88D VWPS
FROM NRN GA...WRN SC AND CNTRL NC SHOW 50 TO 60 KT OF DEEP LAYER
SHEAR ASSOCIATED WITH THE EXIT REGION OF WELL-DEFINED MID-LEVEL JET
WHICH SHOULD CONTINUE TO SUPPORT SUPERCELL DEVELOPMENT THIS EVENING.
IN ADDITION...0-3 KM STORM RELATIVE HELICITIES IN THE 400 TO 450
M2/S2 RANGE COMBINED WITH RELATIVELY LOW LCL HEIGHTS SHOULD BE
FAVORABLE FOR TORNADOES WITH THE MORE INTENSE ROTATING STORMS. THE
STORMS ARE LOCATED ALONG A STALLED FRONT WHERE STORM INTERACTIONS
WITH THE BOUNDARY MAY LOCALLY ENHANCE THE POTENTIAL FOR TORNADOES.
THE GREATEST TORNADO THREAT MAY EXIST ACROSS CNTRL NC INTO FAR
SCNTRL VA CLOSER TO THE CENTER OF THE LOW-LEVEL JET. LARGE HAIL WILL
LIKELY ACCOMPANY SUPERCELLS WITH THE HAIL THREAT EXTENDING WELL TO
THE SOUTHWEST ACROSS NCNTRL GA WHERE OBJECTIVE ANALYSIS SHOWS A
POCKET OF STEEP MID-LEVEL LAPSE RATES. THE WIND DAMAGE THREAT MAY
INCREASE LATER THIS EVENING IF THE STORMS CAN CONGEAL INTO A
LINE....MOVING INTO SRN NC AND ERN SC AFTER MIDNIGHT.
...SRN FLORIDA...
A MULTI-SEGMENTED LINE OF STORMS IS CURRENTLY LOCATED JUST NORTH OF
LAKE OKEECHOBEE WHERE SFC DEWPOINTS ARE IN THE UPPER 60S F AND
OBJECTIVE ANALYSIS SHOWS 1000 TO 1500 J/KG OF MLCAPE. THE
INSTABILITY COMBINED WITH INCREASING LARGE-SCALE ASCENT SHOULD
CONTINUE TO SUPPORT THE LINE OF STORMS MOVING SSEWD INTO THE MIAMI
AREA LATER THIS EVENING. THE 00Z MIAMI SOUNDING SHOWS ABOUT 1600
J/KG OF MLCAPE WITH 55-60 KT OF DEEP LAYER SHEAR AND SUBSTANTIAL
DIRECTIONAL SHEAR BELOW 850 MB. THIS COMBINED WITH INCREASING
LOW-LEVEL FLOW THIS EVENING MAY BE SUFFICIENT FOR AN ISOLATED WIND
DAMAGE THREAT WITH THE STRONGER CELL ELEMENTS IN THE LINE.
