SWODY2
SPC AC 190616
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0116 AM CDT FRI MAR 19 2010
VALID 201200Z - 211200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF SRN LA THROUGH
SRN MS...
...SYNOPSIS...
PROGRESSIVE UPPER PATTERN WILL PERSIST THROUGH SATURDAY. THE UPPER
TROUGH DROPPING THROUGH THE GREAT BASIN AS OF EARLY FRIDAY MORNING
WILL AMPLIFY SEWD...REACHING THE SRN HIGH PLAINS SATURDAY MORNING.
THIS FEATURE IS FORECAST TO CLOSE OFF OVER THE SRN PLAINS AND LOWER
MS VALLEY SATURDAY EVENING. VORT MAX CURRENTLY OVER NRN BAJA WILL
MOVE THROUGH SRN TX SATURDAY REACHING THE LOWER MS VALLEY DURING THE
EVENING. THIS IMPULSE IS FORECAST TO WEAKEN AS IT BECOMES ABSORBED
BY THE LARGER UPPER TROUGH. A STRONG COLD FRONT DELINEATING A SURGE
OF CP AIR WILL DROP SWD THROUGH THE SRN PLAINS DURING THE DAY.
CYCLOGENESIS WILL LIKELY BE UNDERWAY FROM ERN TX INTO THE LOWER MS
VALLEY SATURDAY AFTERNOON AND EVENING ALONG THE BAROCLINIC ZONE IN
ASSOCIATION WITH UPPER JET THAT WILL ROTATE THROUGH THE BASE OF THE
UPPER TROUGH.
...SRN PARTS OF THE GULF COAST STATES...
AREA OF CP HIGH PRESSURE OVER THE GULF WILL LIMIT BOUNDARY LAYER
MODIFICATION. THE HIGH WILL MOVE EAST FRIDAY INTO SATURDAY WITH SELY
NEAR SURFACE WINDS BECOMING ESTABLISHED OVER MUCH OF THE GULF BY
FRIDAY NIGHT. WITH THE GULF SLOW TO MODIFY AND THE MORE SIGNIFICANT
SLY LOW-LEVEL JET NOT FORECAST TO BECOME ESTABLISHED UNTIL SATURDAY
EVENING IN RESPONSE TO DEVELOPING CYCLONE...MOISTURE RETURN WILL
LIKELY REMAIN MODEST. LOW TO MID 50F DEWPOINTS WILL LIKELY ADVECT
JUST INLAND FROM THE COAST WITH DEWPOINTS AROUND 60F ALONG THE
COASTAL AREAS. TEMPERATURES ALOFT WILL REMAIN RATHER COOL WHICH
COULD COMPENSATE FOR THE LIMITED MOISTURE TO SOME EXTENT...BUT
INSTABILITY IS EXPECTED TO REMAIN VERY MARGINAL WITH MUCAPE
GENERALLY BELOW 500 J/KG POSSIBLE AS MOISTURE ADVECTS NWD OVERNIGHT.
FORCED BAND OF CONVECTION WILL PERSIST WITHIN ZONE OF DEEP ASCENT
ASSOCIATED WITH UPPER TROUGH AND ITS ATTENDANT BAROCLINIC ZONE.
ACTIVITY WILL BE EMBEDDED WITHIN STRONG DEEP SHEAR AND HODOGRAPH
SIZE WILL ALSO INCREASE AS LOW-LEVEL JET STRENGTHENS OVERNIGHT. MAIN
THREAT APPEARS TO BE ISOLATED STRONG TO DAMAGING WIND GUSTS OVER SRN
PARTS OF GULF COAST STATES OVERNIGHT WHERE ACTIVITY WILL HAVE A
BETTER CHANCE OF BEING ROOTED NEAR THE SURFACE. THE WEAK
THERMODYNAMIC ENVIRONMENT MAY ULTIMATELY SERVE AS A LIMITING FACTOR
FOR A MORE ROBUST SEVERE EVENT.
...CNTRL THROUGH SERN TX...
A BAND OF STORMS WILL BE ONGOING WITHIN ZONE OF FORCED ASCENT IN
VICINITY OF SEWD ADVANCING COLD FRONT. STORMS DEVELOPING ALONG SRN
END OF THIS BAND WILL EXIST WITHIN A STEEPER LAPSE RATE
ENVIRONMENT...BUT INSTABILITY WILL REMAIN MARGINAL DUE TO LIMITED
LOW-LEVEL MOISTURE RETURN. SOME RISK FOR ISOLATED STRONG WIND GUSTS
AND HAIL WILL EXIST AS ACTIVITY DEVELOPS SEWD DURING THE DAY.
HOWEVER...OVERALL THREAT DOES NOT APPEAR SUFFICIENT TO WARRANT MORE
THAN 5% SEVERE PROBABILITIES.
..DIAL.. 03/19/2010
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