SPC AC 150733
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0133 AM CST TUE DEC 15 2009
VALID 171200Z - 181200Z
...SYNOPSIS...
MODEL CONSENSUS IS THAT UPPER PATTERN WILL BEGIN THE PROCESS OF
AMPLIFICATION LATE THURSDAY AS A NRN STREAM SHORTWAVE TROUGH DROPS
SEWD THROUGH THE NRN AND CNTRL ROCKIES AND PLAINS. IN THE PROCESS A
SRN STREAM SHORTWAVE TROUGH WILL DEAMPLIFY AS IT EJECTS EWD INTO THE
CNTRL GULF OF MEXICO. MODEST SURFACE CYCLOGENESIS IS FORECAST OVER
THE CNTRL GULF IN ASSOCIATION WITH THIS FEATURE ALONG WITH NWD
RETREAT OF A WARM FRONT THROUGH SRN FL.
...SRN FL...
SLY LOW-LEVEL FLOW WILL STRENGTHEN LATER THURSDAY OVER THE ERN GULF
AND THE FL PENINSULA DOWNSTREAM FROM EWD ADVANCING SHORTWAVE TROUGH
AND ITS ATTENDANT SURFACE LOW. INCREASING THETA-E ADVECTION AND
ISENTROPIC LIFT WITHIN THE DEVELOPING WARM ADVECTION REGIME WILL
CONTRIBUTE TO DESTABILIZATION AND THE DEVELOPMENT OF CONVECTION
ACROSS THE FL PENINSULA DURING THE DAY. SURFACE BASED THUNDERSTORMS
WILL BECOME POSSIBLE LATER THURSDAY OVER S FL WHERE DEWPOINTS IN THE
UPPER 60S WILL RESIDE. DEPENDING ON SPEED OF THE SRN STREAM
IMPULSE...DEEP LAYER WIND AND VERTICAL SHEAR MAY BECOME SUFFICIENT
FOR A THREAT OF ROTATING STORMS. THE LIKELIHOOD OF WIDESPREAD WARM
ADVECTION PRECIPITATION...POOR LAPSE RATES AND MODEST INSTABILITY IN
THE WARM SECTOR WILL SERVE AS OVERALL LIMITING FACTORS. THIS AND
UNCERTAINTY REGARDING TIMING AND STRENGTH OF SRN STREAM IMPULSE
PRECLUDE MORE THAN 5% SEVERE PROBABILITIES AT THIS TIME.
..DIAL.. 12/15/2009
CLICK TO GET WUUS03 PTSDY3 PRODUCT
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0830Z
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