SPC AC 121230
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0730 AM CDT WED MAR 12 2008
VALID 121300Z - 131200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
PROGRESSIVE SPLIT FLOW REGIME WILL PERSIST THROUGH THE DAY ONE
PERIOD. SEVERAL SHORT WAVE TROUGHS WILL BE EMBEDDED WITHIN THIS
LARGER-SCALE PATTERN THOUGH THE PRIMARY FEATURES OF INTEREST WILL
BE: 1) IMPULSE TRANSLATING FROM THE NRN PLAINS EWD ACROSS THE GREAT
LAKES AND 2) SRN BRANCH SYSTEM WHICH WILL MOVE FROM THE CNTRL GULF
COAST ESEWD ACROSS THE FL PENINSULA.
IN THE LOW LEVELS...WEAK CYCLONE DEVELOPMENT IS FORECAST TO OCCUR IN
ASSOCIATION WITH THE FORMER SYSTEM MENTIONED ABOVE WITH THIS FEATURE
DEVELOPING GENERALLY EWD FROM THE MID MO VALLEY INTO THE UPPER
MIDWEST. A WARM FRONT ATTENDANT TO THIS LOW WILL LIFT NEWD THROUGH
THE MID MS AND LOWER OH VALLEYS THROUGH THE FORECAST PERIOD.
MEANWHILE...TRAILING COLD FRONT WILL PUSH SWD THROUGH THE CNTRL INTO
SRN PLAINS.
...OH VALLEY/UPPER GREAT LAKES...
LOW-LEVEL MOISTURE WILL REMAIN QUITE LIMITED AHEAD OF SURFACE LOW
AND COLD FRONT. HOWEVER...A PLUME OF STEEP MIDLEVEL LAPSE RATES
WILL BE COINCIDENT WITH UPPER SYSTEM...CONTRIBUTING TO POCKETS OF
WEAK CONVECTIVE INSTABILITY WITH MUCAPES 200-400 J/KG. ELEVATED
TSTMS WILL BECOME INCREASINGLY LIKELY TONIGHT N OF WARM FRONT ALONG
NOSE OF STRENGTHENING LLJ WHERE FORCING FOR ASCENT VIA WAA ACTS ON
DESTABILIZING ENVIRONMENT.
...SERN FL PENINSULA...
WLY LOW-LEVEL FLOW WILL EXIST TODAY AHEAD OF WEAK FRONTAL BOUNDARY
SAGGING SWD THROUGH THE PENINSULA. THIS SHOULD SERVE TO ENHANCE
CONVERGENCE ALONG SEA-BREEZE BOUNDARY AS IT PUSHES ALONG/OFF THE
SERN FL COAST THIS AFTERNOON. AIR MASS IS EXPECTED TO REMAIN MOIST
/DEWPOINTS IN THE LOWER TO MID 60S/ AND AT LEAST WEAKLY UNSTABLE
WITH MLCAPES AROUND 500 J/KG. FORCING FOR ASCENT ASSOCIATED WITH
APPROACHING MIDLEVEL TROUGH COUPLED WITH THE INCREASING CONVERGENCE
IN THE LOW LEVELS SHOULD BE SUFFICIENT TO INITIATE SHOWERS AND
ISOLATED TSTMS ALONG THE IMMEDIATE COAST THIS AFTERNOON INTO
EVENING.
..MEAD/EVANS.. 03/12/2008
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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