DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CST FRI FEB 19 2010

VALID 201200Z - 211200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
LARGE SCALE SPLIT FLOW REGIME WILL PREVAIL OVER THE WESTERN PART OF
NORTH AMERICA ON SATURDAY...WITH PROGRESSIVE/LOW AMPLITUDE
WESTERLIES ESPECIALLY OVER THE SOUTHERN/EASTERN PORTIONS OF THE
CONUS. A SOUTHERN STREAM SHORTWAVE TROUGH WILL ADVANCE EASTWARD FROM
SOUTHERN CA/NORTHERN BAJA AT THE BEGINNING OF THE PERIOD...TO THE
SOUTHERN HIGH PLAINS BY SUNDAY MORNING. SHORTWAVE TROUGH ATTENDANT
PACIFIC COLD FRONT WILL CROSS THE SOUTHWEST DESERTS/MEXICO BORDER
VICINITY...WHILE SURFACE CYCLOGENESIS GRADUALLY OCCURS ACROSS THE
SOUTHERN HIGH PLAINS WITH A SURFACE BOUNDARY BECOMING ESTABLISHED IN
A GENERAL SOUTHWEST-NORTHEAST ORIENTED FASHION FROM THE SOUTHERN
HIGH PLAINS TO THE OZARKS.

...OK/NORTH TX...
WITH THE SOUTHERN STREAM SHORTWAVE TROUGH NOT EXPECTED TO REACH THE
SOUTHERN HIGH PLAINS UNTIL SATURDAY NIGHT...AND WITH A MODIFIED GULF
AIRMASS ONLY BEGINNING TO RETURN NORTHWARD TOWARD THE REGION...MUCH
OF THE SOUTHERN PLAINS SHOULD REMAIN CAPPED/FREE OF DEEP CONVECTION
THROUGH PEAK HEATING. HOWEVER...SATURDAY EVENING AND ESPECIALLY
OVERNIGHT/EARLY SUNDAY MORNING...SHOWERS/TSTMS SHOULD APPRECIABLY
INCREASE ACROSS PORTIONS OF NORTHWEST/NORTH TX AND MUCH OF OK INTO
SOUTHERN KS/OZARKS VICINITY...WITH THE ARRIVAL OF LARGE SCALE
FORCING FOR ASCENT COINCIDENT WITH AN INCREASING SOUTHERLY LOW LEVEL
JET/MOISTURE TRANSPORT REGIME ABOVE A COOL/STABLE SURFACE LAYER.
WITH SUFFICIENT SHEAR EXPECTED IN THE CLOUD BEARING
LAYER...STEEPENING MID LEVEL LAPSE RATES AND WEAK ELEVATED
INSTABILITY...300-750 J/KG MUCAPE PER 12Z GFS/NAM GUIDANCE...WOULD
IMPLY SOME POTENTIAL FOR MARGINALLY SEVERE HAIL MAINLY AFTER 03Z.

...CA/SRN AZ...
ATTENDANT TO THE INLAND ADVANCING UPPER LOW/FRONTAL BAND...A BROKEN
SQUALL LINE SHOULD BE AFFECTING COASTAL AREAS OF SOUTHERN CA AT THE
BEGINNING OF THE PERIOD. DECREASING MOIST INFLUX/INSTABILITY AWAY
FROM SOUTHERN CA SUGGESTS A LIMITED/VIRTUALLY NIL POTENTIAL FOR
SEVERE WEATHER ATTENDANT TO THE EASTWARD ADVANCING SHORTWAVE
TROUGH/FRONTAL CONVECTION. FARTHER NORTH...IT IS ALSO CONCEIVABLE
THAT ISOLATED TSTMS MAY DEVELOP ACROSS THE SACRAMENTO VALLEY OF
NORTHERN CA SATURDAY AFTERNOON/EARLY EVENING