SPC AC 281720
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1120 AM CST THU DEC 28 2006
VALID 291200Z - 301200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF CNTRL AND EAST
TX...LA...SRN OK AND FAR SW AR...
...SRN PLAINS/LOWER MS VALLEY...
AN UPPER-LEVEL LOW OVER THE DESERT SOUTHWEST WILL GRADUALLY OPEN
TONIGHT INTO FRIDAY...SLOWLY DRIFTING EWD ACROSS THE SRN ROCKIES.
AHEAD OF THE SYSTEM...A WELL-DEVELOPED LOW-LEVEL JET WILL TRANSPORT
MOISTURE NWD ACROSS THE SRN PLAINS WITH SFC DEWPOINTS LIKELY RISING
INTO THE 60S F ACROSS EAST TX AND MOST OF LA BY FRIDAY AFTERNOON.
STRONG LARGE-SCALE ASCENT ASSOCIATED WITH THE UPPER-TROUGH WILL
SPREAD EWD INTO CNTRL TX AND WRN OK EARLY IN THE DAY LIKELY
RESULTING IN THE INITIATION OF SCATTERED THUNDERSTORMS ALONG A
FRONTAL BOUNDARY LOCATED FROM NEAR LAWTON OK EXTENDING SWD INTO THE
TX HILL COUNTRY. STORM COVERAGE SHOULD STEADILY INCREASE DURING THE
DAY WITH A SOLID LINE OF THUNDERSTORMS DEVELOPING BY FRIDAY EVENING
FROM CNTRL OK EXTENDING SWD TO THE HOUSTON AREA.
SHEAR PROFILES WILL GRADUALLY STRENGTHEN AHEAD OF THE APPROACHING
UPPER-LEVEL SYSTEM AS THE LOW-LEVEL JET AND MID-LEVEL FLOW INCREASE.
THIS SHOULD SUPPORT SUPERCELLS EARLY IN THE DEVELOPMENT OF THE LINE
WITH FORECAST SOUNDINGS ACROSS CNTRL TX LATE FRIDAY AFTERNOON
SHOWING 0-6 KM SHEAR VALUES REACHING 50-60 KTS. SUPERCELLS WILL BE
MOST LIKELY EARLY IN THE EVENT ALONG THE I-35 CORRIDOR NEAR A
THERMAL AXIS WHERE MID-LEVEL LAPSE RATES SHOULD BE STEEPEST AND
VERTICAL SHEAR WILL BE STRONGEST. VERTICAL SHEAR WILL BE WEAKER
FURTHER EAST BUT STILL SHOULD SUPPORT ISOLATED SUPERCELLS AND/OR
MULTICELL SEVERE STORMS IN THE AFTERNOON WELL EAST OF THE BOUNDARY
ACROSS EAST TX AND WRN LA. AN ISOLATED TORNADO THREAT MAY EXIST WITH
ANY SUPERCELLS THAT DEVELOP IN THE AFTERNOON. HOWEVER...THE GREATEST
SEVERE THREAT SHOULD BE WIND DAMAGE AS A SOLID LINE FORMS AND MOVES
EWD ACROSS EAST TX FRIDAY EVENING. THE LOW-LEVEL JET WILL STRENGTHEN
FRIDAY NIGHT RESULTING IN VERY STRONG LOW-LEVEL SHEAR PROFILES. AS A
RESULT...THE TORNADO THREAT MAY INCREASE ACROSS EAST TX AND POSSIBLY
ACROSS SW LA OVERNIGHT. ALTHOUGH THE SEVERE WEATHER POTENTIAL
REMAINS MORE UNCERTAIN ACROSS CNTRL AND SRN LA...AN ISOLATED SEVERE
THREAT COULD CONTINUE THROUGH LATE FRIDAY NIGHT IF THE SQUALL-LINE
REMAINS ORGANIZED.
..BROYLES.. 12/28/2006
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0800Z
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