SPC AC 070559
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT SUN SEP 07 2008
VALID 081200Z - 091200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS S FL AND THE KEYS...
...SYNOPSIS...
FAIRLY STRONG MID-LEVEL SHORT-WAVE TROUGH IS FORECAST TO MOVE EWD
ACROSS THE NRN PLAINS/GREAT LAKES/MIDWEST/OH VALLEY REGION THIS
PERIOD...WHILE A SECOND TROUGH BEGINS DIGGING SEWD ACROSS WRN CANADA
AND THE NWRN CONUS.
AT THE SURFACE...A COLD FRONT ASSOCIATED WITH THE N CENTRAL U.S.
UPPER TROUGH IS FORECAST TO MOVE EWD ACROSS THE MIDWEST/OH VALLEY
REGION...AND SEWD INTO THE SRN PLAINS. MEANWHILE...HURRICANE IKE IS
EXPECTED TO MOVE WNWWD ACROSS CUBA THROUGH THE PERIOD.
...SRN FL AND THE KEYS...
AS IKE MOVES WNWWD ACROSS CUBA -- PER THE LATEST FORECAST FROM THE
NHC...CONVECTIVE BANDS AND STRONG LOW-LEVEL FLOW FIELD WILL SPREAD
ACROSS S FL AND THE KEYS THROUGH THE DAY. MOST FAVORABLE LOW-LEVEL
SHEAR IS FORECAST DURING THE SECOND HALF OF THE PERIOD...AS THE
CENTER OF IKE MOVES E OF 80 DEGREES WEST LONGITUDE. AS THIS OCCURS
-- ALLOWING THE NERN QUADRANT OF THE STORM TO BEGIN AFFECTING THE
OUTLOOK AREA -- THE THREAT FOR ISOLATED TORNADOES WILL LIKEWISE
INCREASE.
...ERN KS/ERN OK NEWD ACROSS THE MID MS AND OH VALLEYS...
AS COOLER AIR MOVES SWD OUT OF CANADA ACROSS THE PLAINS...A COLD
FRONT IS FORECAST TO SHARPEN ACROSS KS. WITH TIME...A FRONTAL WAVE
IS EXPECTED TO SHIFT NEWD FROM THE TX/OK PANHANDLE REGION ACROSS THE
MID MS VALLEY...AND THEN INTO THE GREAT LAKES REGION LATE. AS THIS
OCCURS...THE TRAILING COLD FRONT WILL MOVE SWD INTO THE SRN
PLAINS...AND SEWD ACROSS THE MID MS/OH VALLEY REGION.
STORMS -- LIKELY ONGOING AT THE START OF THE PERIOD ACROSS THE
CENTRAL PLAINS -- SHOULD INCREASE NEAR AND TO THE COOL SIDE OF THE
FRONT DURING THE AFTERNOON ACROSS MO AND VICINITY...AND THEN ENEWD
ACROSS THE MIDWEST/OH VALLEY THROUGH THE END OF THE PERIOD.
GREATEST INSTABILITY IS FORECAST ACROSS KS/MO/OK DURING THE
DAY...WHICH WILL SUPPORT A FEW STRONGER CELLS. HOWEVER...STRONGER
FLOW ALOFT WILL REMAIN N OF THE FRONT...AND THUS EXPECT GENERALLY
MULTICELL STORMS -- AND ASSOCIATED/MARGINAL SEVERE THREAT.
AS STORMS DEVELOP ENEWD OVERNIGHT...MARGINAL INSTABILITY SUGGESTS
ONLY A LOW-END SEVERE THREAT DESPITE SOMEWHAT STRONGER FLOW ALOFT.
THUS...WILL EXPAND A LOW-PROBABILITY THREAT AREA ALONG THE FRONTAL
ZONE.
..GOSS.. 09/07/2008
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
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