SPC AC 090054
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0754 PM CDT TUE APR 08 2008
VALID 090100Z - 091200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM INDIANA/IL SWWD INTO TX...
...INDIANA/IL SWWD ACROSS THE MID MS VALLEY INTO CENTRAL/NERN TX...
THUNDERSTORMS ARE ONGOING ATTM AHEAD OF COLD FRONT...IN THE FORM OF
A SLOWLY INCREASING LINE FROM N CENTRAL IL SSWWD INTO SRN MO...AND
THEN WSWWD ACROSS AR AND INTO NERN AND CENTRAL TX AS ISOLATED
CELLULAR STORMS.
GREATEST INSTABILITY EXISTS ATTM FROM CENTRAL AR WSWWD ACROSS TX
INTO THE HILL COUNTRY...WHERE GENERALLY 500 TO 1500 J/KG MIXED-LAYER
CAPE IS INDICATED. FURTHER N -- FROM SRN MO NNEWD...INSTABILITY IS
MUCH MORE LIMITED -- WITH WIDESPREAD CLOUD COVER HAVING HINDERED
DAYTIME HEATING. NONETHELESS...WITH 50S DEWPOINTS SPREADING SLOWLY
NWD TOWARD LK MI...UP TO 500 J/KG SURFACE-BASED CAPE SHOULD CONTINUE
TO SUPPORT STORMS ACROSS THIS REGION.
DEEP-LAYER WIND FIELD REMAINS SUPPORTIVE OF SUPERCELLS ACROSS
TX...WITH SLY LOW-LEVEL FLOW VEERING/INCREASING WITH HEIGHT THROUGH
THE MID LEVELS TO AROUND 40 KT. ALONG WITH THREAT FOR LARGE
HAIL...A FEW LOCALLY-DAMAGING GUSTS WILL BE POSSIBLE OVER THE NEXT
FEW HOURS.
MEANWHILE...MUCH STRONGER DEEP-LAYER WIND FIELD IS INDICATED FROM E
CENTRAL MO NWD INTO THE UPPER GREAT LAKES REGION...IN CONJUNCTION
WITH WELL-DEFINED VORT MAX NOW CROSSING ERN IA/NWRN IL/SWRN WI.
WHILE LESSER SEVERE THREAT APPEARS TO EXIST ACROSS MUCH OF THE
REGION FROM NRN AR NNEWD...WILL MAINTAIN SLIGHT RISK ACROSS THIS
REGION AS STRENGTH OF FLOW ALOFT COULD SUPPORT LOCALLY SEVERE
STORMS/LINE SEGMENTS INTO THE OVERNIGHT HOURS.
ALSO OVERNIGHT...STORMS ARE FORECAST TO DEVELOP ACROSS PARTS OF THE
HIGH PLAINS OF TX...AS 40 KT SELY/ESELY LOW-LEVEL JET DEVELOPS AHEAD
OF THE MAIN UPPER TROUGH CROSSING THE SWRN CONUS. STEEP LAPSE RATES
ATOP LOW-LEVEL THETA-E ADVECTION SHOULD YIELD SUFFICIENT
DESTABILIZATION ATOP THE STABLE BOUNDARY LAYER TO RESULT IN
POTENTIALLY-VIGOROUS ELEVATED STORMS. DEGREE OF INSTABILITY
COMBINED WITH AMPLE /ROUGHLY 40 KT/ SWLYS AT MID LEVELS SUGGESTS
THAT A FEW OF THE STRONGER STORMS MAY PRODUCE HAIL THROUGH THE END
OF THE PERIOD.
..GOSS.. 04/09/2008
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
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