SPC AC 081257
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0657 AM CST SAT NOV 08 2008
VALID 081300Z - 091200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
AMPLIFIED AND INCREASINGLY PROGRESSIVE FLOW REGIME WILL ENSUE ACROSS
MUCH OF THE CONUS STARTING TODAY AS THE CENTER OF A DEEP-LAYER
CYCLONE ACROSS THE GREAT LAKES REGION PIVOTS NNEWD INTO CANADA AHEAD
OF ANOTHER STRONG IMPULSE AND DEVELOPING LOW CENTER DROPPING SEWD
TOWARD MN/WI. THE RESULTING BELT OF FAST CYCLONIC FLOW WITHIN THE
BASE AND ERN FLANK OF THIS DEVELOPING COMPLEX TROUGH WILL SPREAD
ACROSS THE MID ATLANTIC AND NEW ENGLAND REGIONS THROUGH EARLY
SUNDAY. COLD FRONT ASSOCIATED WITH THE GREAT LAKES LOW...NOW
SITUATED FROM NY TO NRN FL...WILL ADVANCE EAST AND OFF MOST OF THE
MID ATLANTIC COAST THROUGH THE AFTERNOON WHILE MAKING SLIGHTLY
SLOWER EWD PROGRESS ACROSS NEW ENGLAND THROUGH THIS EVENING.
ON THE OTHER COAST...POTENT PACIFIC TROUGH...NOW MOVING ONSHORE FROM
NRN CA TO WA...WILL PRODUCE SUBSTANTIAL HEIGHT FALLS OF 150-200M PER
12 HOURS FROM THE SRN CASCADES TO NRN CA/SIERRA NEVADA RANGE THROUGH
LATE TODAY. STRONG PACIFIC JET OVER 100KT WITHIN THE WRN FLANK OF
THIS TROUGH WILL SUPPORT RAPID AMPLIFICATION AND DIGGING OF THE
MID/UPPER LEVEL TROUGH SEWD ACROSS CA AND MUCH OF WRN NV BY SUNDAY
MORNING.
...ERN NV TO NEW ENGLAND...
POCKET OF HIGHER THETA-E AIR AND LIFT WITH THE COLD FRONT MAY
SUPPORT THE DEVELOPMENT OF WIDELY SCATTERED CONVECTION FROM ERN NC
TO NEW ENGLAND THROUGH THIS EVENING. WARM/MOIST MARITIME AIR MASS
AND INCREASINGLY STRONG DYNAMIC FORCING FOR ASCENT SPREADING EAST
MAY ALSO LEAD TO AN INCREASE IN COASTAL WATERS TSTMS/LATENT HEATING
AND SECONDARY CYCLOGENESIS OVER SERN NEW ENGLAND. TSTM ORGANIZATION
OVER LAND AREAS EXPECTED TO BE LIMITED BY MARGINAL DEEP-LAYER LAPSE
RATES. HOWEVER...A FEW CLUSTERS OF STRONG/MORE PERSISTENT STORMS
APPEAR POSSIBLE THROUGH THIS EVENING WITHIN/NEAR DEVELOPING
SECONDARY LOW FROM MA TO DOWNEAST ME.
...PAC NW TO NRN GREAT BASIN...
STRONG HEIGHT FALLS AND RAPID DYNAMIC COOLING WILL CONTINUE TO
SPREAD INLAND ACROSS THESE AREAS THROUGH TONIGHT. STEEPENING LAPSE
RATES/LOWERING STATIC STABILITY AND MOISTENING WILL CONTRIBUTE TO
POTENTIAL FOR ISOLATED/EPISODIC THUNDER SHIFTING ACROSS THE OUTLOOK
AREA. WHILE INSTABILITY SHOULD REMAIN TOO MEAGER FOR MORE ORGANIZED
SEVERE STORM THREAT...DYNAMIC AND OROGRAPHIC FORCING AND INCREASING
SHEAR MAY SUPPORT POCKETS OF MORE PERSISTENT/STRONGER CONVECTIVE
UPDRAFTS WITH SOME SMALL HAIL/LOCALLY HIGH WINDS POSSIBLE.
..CARBIN.. 11/08/2008
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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