SPC AC 251300
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0700 AM CST TUE DEC 25 2007
VALID 251300Z - 261200Z
...NO SVR TSTM AREAS FORECAST...
...COASTAL CAROLINAS...
EARLY MORNING WATER VAPOR IMAGERY FEATURES CLOSED UPPER LOW CROSSING
THE LOWER MISSISSIPPI VALLEY AT DAYBREAK. SHORT TERM MODEL GUIDANCE
SUGGESTS THIS UPPER LOW WILL CONTINUE TO TRANSITION
EAST-NORTHEASTWARD TO THE WESTERN CAROLINAS BY TONIGHT...WITH A
SURFACE LOW EXPECTED TO DEEPEN OFF THE COAST OF THE CAROLINAS LATE
IN THE PERIOD. WHILE THE BULK OF THUNDERSTORM ACTIVITY IS EXPECTED
TO REMAIN OVER THE COASTAL WATERS/GULF STREAM...POTENTIAL EXISTS FOR
THUNDERSTORMS INLAND ACROSS THE COASTAL PLAIN OF NC/SC. IN SPITE OF
FAVORABLY ENLARGED LOW LEVEL HODOGRAPHS ALONG THE IMMEDIATE COAST
LATE TONIGHT...OVERALL MODEST BUOYANCY WITH ONLY A FEW HUNDRED J/KG
MUCAPE WOULD LIKELY PRECLUDE A SEVERE THREAT INLAND. POTENTIAL
ONSHORE STORMS WEST OF THE SURFACE LOW WOULD LIKELY BE ROOTED ABOVE
A RELATIVELY STABLE NEAR-SURFACE LAYER PER NAM/NAM-KF FORECAST
SOUNDINGS.
...WA AND ORE COASTS...
WATER VAPOR IMAGERY FEATURES STRONG UPPER TROUGH NEARING THE PACIFIC
NORTHWEST/BRITISH COLUMBIA COAST. CONSISTENT WITH SATELLITE
IMPLICATIONS...LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THAT
CONSIDERABLE HEIGHT FALLS/DYNAMIC COOLING WILL ACCOMPANY THIS UPPER
SYSTEM INTO THE PACIFIC NORTHWEST. LARGELY ATTRIBUTABLE TO
INCREASINGLY COLD MID LEVEL TEMPERATURES /AROUND -35C AT 500
MB/...STEEPENING MID LEVEL LAPSE COUPLED WITH MOIST/ONSHORE FLOW
WILL SUPPORT WEAK DESTABILIZATION THIS AFTERNOON/TONIGHT WITHIN A
POST-FRONTAL REGIME. NAM/NAM-KF FORECAST SOUNDINGS SUGGEST THAT
EQUILIBRIUM TEMPERATURES WILL BECOME SUFFICIENTLY COOL FOR CHARGE
SEPARATION/LIGHTNING DEVELOPMENT IN ASSOCIATION WITH THE DEEPER
CONVECTIVE ELEMENTS MOVING ONTO THE WA/ORE COASTS.
..GUYER.. 12/25/2007
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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