SPC AC 060600
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT WED JUN 06 2007
VALID 071200Z - 081200Z
...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF UPPER MI...MUCH
OF WI...FAR SERN MN...THE ERN HALF OF IA...NRN IL...AND NRN MO...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY/UPPER
GREAT LAKES REGION SWWD INTO OK...
...SYNOPSIS...
POTENT UPPER TROUGH...ACCOMPANIED BY UNSEASONABLY-INTENSE DEEP-LAYER
WIND FIELD -- IS FORECAST TO SURGE NEWD OUT OF THE PLAINS AND ACROSS
THE UPPER MS VALLEY/UPPER GREAT LAKES REGION THROUGH THE PERIOD.
AT THE SURFACE...DEEP /980 MB/ LOW WILL MOVE NEWD FROM SERN SD INTO
SWRN ONTARIO BEFORE SUNSET...AND THEN SHOULD CONTINUE NNEWD TOWARD
HUDSON BAY THROUGH THE REMAINDER OF THE PERIOD. TRAILING COLD FRONT
WILL SWEEP STEADILY EWD ACROSS THE UPPER MS VALLEY THROUGH THE
AFTERNOON...AND SHOULD EXTEND FROM LK SUPERIOR SSWWD ACROSS IL/MO
INTO SERN OK...AND THEN WSWWD INTO SRN NM/W TX BY THE END OF THE
PERIOD.
...UPPER MS VALLEY/UPPER GREAT LAKES SWWD INTO OK...
ANOTHER DAY OF WIDESPREAD/SIGNIFICANT SEVERE WEATHER IS ANTICIPATED
DAY 2...AS VERY STRONG DEEP-LAYER WIND FIELD SPREADS EWD ATOP
MOIST/MODERATELY-UNSTABLE AIRMASS.
STORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS PARTS OF
THE N CENTRAL CONUS...WITH AT LEAST THE REMNANTS OF AN MCS -- AND
ASSOCIATED DAMAGING WINDS -- POSSIBLY SHIFTING NEWD ACROSS THE UPPER
MS VALLEY. HOWEVER...AIRMASS FROM ROUGHLY CENTRAL WI/ERN IA SWWD
SHOULD REMAIN GENERALLY UNTOUCHED BY EARLIER CONVECTION. THUS
EXPECT DAYTIME HEATING COMBINED WITH UPPER 60S TO NEAR 70 BOUNDARY
LAYER DEWPOINTS TO RESULT IN 1500 TO 2500 J/KG MEAN-LAYER CAPE ALONG
ENTIRE FRONTAL ZONE -- AND PERHAPS AS HIGH AS 3000 J/KG AHEAD OF THE
FRONT ACROSS SRN PORTIONS OF THE RISK AREA IN OK.
WHILE CAPPING SHOULD HELP TO SUPPRESS CONVECTIVE DEVELOPMENT THROUGH
MIDDAY -- STORMS SHOULD RAPIDLY DEVELOP BY MID-AFTERNOON INVOF COLD
FRONT. GIVEN LINEAR FORCING ANTICIPATED...EXPECT MODE TO TREND
TOWARD A LINEAR CONFIGURATION RATHER QUICKLY -- ESPECIALLY FROM MO
NEWD ALONG FRONT WHERE STRONGEST UPPER FORCING IS EXPECTED. STORMS
SHOULD REMAIN MORE ISOLATED/CELLULAR FROM ERN KS SWD INTO OK.
IN ANY CASE...DEEP-LAYER SHEAR SHOULD BE EXCEPTIONALLY STRONG FOR
JUNE...THOUGH VEERING WITH HEIGHT SHOULD BE SOMEWHAT LIMITED.
NONETHELESS...0-6KM BULK SHEAR OF 70 TO 80 KT -- AIDED BY 95 KT
MID-LEVEL JET STREAK -- WILL SUPPORT SUPERCELLS...AS WELL AS BOWS
AND EMBEDDED SUPERCELLS WITHIN LINEAR CONVECTIVE ELEMENTS. THOUGH A
FEW SIGNIFICANT TORNADOES ARE EXPECTED...WIDESPREAD/ SIGNIFICANT
WIND DAMAGE APPEARS TO BE THE PRIMARY SEVERE THREAT ATTM...WITH A
DERECHO EXPECTED TO DEVELOP SOMEWHERE IN THE NRN MO/ERN IA/NRN IL/WI
VICINITY BY EVENING. SEVERE THREAT WILL SHIFT EWD/SEWD WITH
TIME...AS STORMS SPREAD ACROSS THE UPPER GREAT LAKES REGION AND
PERHAPS INTO THE MID MS/LOWER OH VALLEY. STORMS SHOULD ALSO EXPAND
IN COVERAGE ALONG SRN FRINGES OF OUTLOOK INTO OK...WHERE SEVERE
THREAT WILL LIKELY PERSIST THROUGH THE END OF THE PERIOD.
..GOSS.. 06/06/2007
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
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