SPC AC 150725
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0225 AM CDT MON SEP 15 2008
VALID 171200Z - 181200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
UPR TROUGH EXPECTED TO BE OVER THE ERN STATES ON WEDNESDAY WILL
BEGIN TO WEAKEN...WITH MORE ROBUST PORTION OF THE TROUGH OVER SE
CANADA/NEW ENGLAND ASSOCD WITH A POLAR VORTEX OVER JAMES BAY.
MEANWHILE...SRN PORTIONS OF THE TROUGH WILL REMAIN OVER THE SRN
APLCNS/SERN STATES AS A MOBILE UPR HIGH BUILDS TOWARD THE MS VLY
FROM THE PLNS STATES. TO THE W...MODELS VARY ON THE EVOLUTION OF A
COMPLEX TROUGH APCHG/ALONG THE W CST. LEAD WAVE EXPECTED TO EJECT
INTO THE WRN GRT BASIN/PAC NW WILL EVENTUALLY PIVOT NWD AS A STRONG
IMPULSE AMPLIFIES/DIGS SEWD TOWARD THE PAC NW CST BY THE END OF THE
PD.
IN THE LWR LVLS...A FRONT ALONG THE SE ATLC CST WILL REMAIN QSTNRY
OVER N FL AND THE NRN GULF BASIN THROUGH THE PD. THIS FRONT AND
SEABREEZES WILL BE THE FOCUS FOR NON-SVR TSTMS.
...INTERMOUNTAIN W/NW GRT BASIN...
LOW-LVL MOISTURE WILL LIKELY STREAM FROM THE LWR CO RVR VLY NWD INTO
PARTS OF NV AND UT BY WEDNESDAY AFTN. SRN PERIPHERY OF THE
AFOREMENTIONED NEGATIVE-TILT TROUGH WILL SKIRT E NV/UT DURING THE
DAY AND MAY BE IMPETUS FOR TSTMS. A FEW OF THESE STORMS MAY PRODUCE
GUSTY WINDS AS THEY WILL LIKELY BE HIGH-BASED. IF FORCING FOR
ASCENT ENDS UP BEING MORE ROBUST THAN EXPECTED...THERE EVENTUALLY
COULD BE A LOW PROBABILITY FOR SEMI-ORGANIZED TSTMS.
HOWEVER...MODEL SPREAD WITH THE HANDLING OF THE LEAD UPR WAVE IS
HIGH AND THIS UNCERTAINTY WILL PRECLUDE AN ADDITION OF SVR
PROBABILITIES ATTM.
..RACY.. 09/15/2008
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NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z