SPC AC 081234
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0634 AM CST THU JAN 08 2009
VALID 081300Z - 091200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
DEAMPLIFICATION OF THE LARGE SCALE PATTERN IS UNDERWAY AS MID LEVEL
TROUGH OVER THE ERN CONUS TRANSLATES EWD TO THE WRN ATLANTIC...AND
AN UPSTREAM SHORTWAVE TROUGH MOVES INLAND FROM WA/ORE TO THE NRN
GREAT BASIN AND NRN ROCKIES. ANY THUNDERSTORM THREAT ASSOCIATED
WITH THE ERN CONUS TROUGH...SPECIFICALLY AN EMBEDDED SHORTWAVE
TROUGH MOVING ESEWD FROM KY TO NC AND A SECONDARY FRONTAL SURGE
ACROSS ERN NC THIS EVENING...SHOULD REMAIN OFFSHORE WHERE
SENSIBLE/LATENT HEAT FLUXES FROM THE GULF STREAM MORE STRONGLY
DESTABILIZE THE LOWER TROPOSPHERE. LEE CYCLOGENESIS ACROSS THE
PLAINS WILL INDUCE LOW-LEVEL MOISTURE RETURN INTO S TX BY
TONIGHT...BUT THE MOISTENING WILL OCCUR BENEATH VERY WARM MID LEVEL
TEMPERATURES AND A RESULTANT CAP. THE ONLY APPRECIABLE THUNDERSTORM
THREAT TODAY WILL BE FOCUSED FROM ERN ORE INTO SW ID ALONG THE PATH
OF THE PAC NW/NRN GREAT BASIN SHORTWAVE TROUGH.
...ERN ORE/SW ID THIS AFTERNOON...
WATER VAPOR IMAGERY AND RECENT SHORT TERM MODEL FORECASTS AGREE THAT
THE MID LEVEL TROUGH NOW APPROACHING THE WA/ORE COASTS WILL MOVE
ESEWD TO THE NRN GREAT BASIN BY THIS EVENING. CONDITIONALLY
UNSTABLE LOW-MID LEVEL LAPSE RATES ACCOMPANYING THE MID LEVEL
THERMAL TROUGH WILL ALLOW FOR THE DEVELOPMENT OF WEAK INSTABILITY
ACROSS ORE/ID IN THE IMMEDIATE POST-FRONTAL ENVIRONMENT THIS
AFTERNOON. FORECAST SOUNDINGS FROM THIS AREA SHOW THE POTENTIAL FOR
MUCAPE TO REACH 100-200 J/KG WITH EQUILIBRIUM LEVEL TEMPERATURES
COLDER THAN -20 C. THESE THERMODYNAMIC PROFILES WILL BE SUPPORTIVE
OF AT LEAST ISOLATED LIGHTNING PRODUCTION IN THE MORE VIGOROUS
CONVECTIVE ELEMENTS ASSOCIATED WITH A BAND OF MID LEVEL DCVA
DOWNSTREAM FROM THE MID LEVEL TROUGH AXIS.
..THOMPSON.. 01/08/2009
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NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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