SPC AC 191716
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1116 AM CST THU NOV 19 2009
VALID 201200Z - 211200Z
...NO SVR TSTM AREAS FORECAST...
...SOUTH TEXAS...
A POSITIVELY-TILTED UPPER-LEVEL TROUGH OVER FAR ERN NM WILL MOVE EWD
ACROSS THE SRN PLAINS FRIDAY BECOMING CLOSED-OFF IN NCNTRL TX.
AT THE SFC...A COLD FRONT IN THE WRN TX HILL COUNTRY FRIDAY MORNING
IS FORECAST TO MOVE SEWD ACROSS SOUTH TX BY AFTERNOON. LARGE-SCALE
ASCENT AND WARM ADVECTION SHOULD RESULT IN ELEVATED THUNDERSTORMS
ONGOING ALONG THIS BOUNDARY FRIDAY MORNING. CONVECTIVE COVERAGE
SHOULD GRADUALLY EXPAND AS THE STORMS MOVE SEWD INTO SOUTH TX FRIDAY
AFTERNOON. FORECAST SOUNDINGS ACROSS THE WARM SECTOR IN THE LOWER TX
COASTAL PLAINS FRIDAY AFTERNOON SHOW AN INCREASINGLY DEEP MOIST
LAYER WITH SEWD EXTENT SUGGESTING SFC-BASED THUNDERSTORM DEVELOPMENT
WILL BECOME MORE FAVORABLE AS THE FRONT APPROACHES THE COASTAL
AREAS. ALTHOUGH LAPSE RATES WILL BE ON THE MARGINAL SIDE FOR STRONG
UPDRAFTS...ENOUGH VERTICAL SHEAR SHOULD EXIST ALONG WITH THE MOIST
BOUNDARY LAYER FOR A MARGINAL THREAT FOR WET DOWNBURSTS. THE THREAT
SHOULD BE GREATEST FROM VICTORIA SSWWD TO THE BROWNSVILLE AREA WHERE
LOW-LEVEL FLOW IS FORECAST TO BE MAXIMIZED NEAR PEAK HEATING. IF A
SUPERCELL CAN DEVELOP...THEN A MARGINAL TORNADO THREAT WILL ALSO BE
POSSIBLE.
..BROYLES.. 11/19/2009
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z
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