MESO: Mesoscale Discussion 1908

ACUS11 KWNS 280250
SWOMCD
SPC MCD 280249
MNZ000-SDZ000-NEZ000-280415-

MESOSCALE DISCUSSION 1908
NWS STORM PREDICTION CENTER NORMAN OK
0949 PM CDT MON AUG 27 2007

AREAS AFFECTED...SERN SD THROUGH SWRN MN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 280249Z - 280415Z

ELEVATED STORMS DEVELOPING OVER SERN SD MAY POSE A THREAT FOR HAIL.
A WW IS UNLIKELY UNLESS STORMS BEGIN TO SHOW EVIDENCE OF
INTENSIFICATION. AREA WILL CONTINUE TO BE MONITORED.

A COLD FRONT EXTENDS FROM A SURFACE LOW IN SWRN MN SWWD THROUGH SERN
SD THROUGH SWRN NEB MOVING SLOWLY SEWD. PRE-FRONTAL WARM SECTOR
REMAINS VERY UNSTABLE...BUT A ZONE OF STRONG MUCAPE PERSISTS IN POST
FRONTAL REGION ACROSS SERN SD. MOST OF THIS CAPE RESULTS FROM
PARCELS THAT CAN BE LIFTED FROM BELOW 800 MB. CHARACTER AND MOTION
OF DEVELOPING STORMS OVER SERN SD SUGGEST THEY ARE STILL ROOTED
ABOVE A STRONG INVERSION THAT WAS EVIDENT ON MOST 00Z RAOBS.
ACTIVITY IS DEVELOPING WITHIN A ZONE OF MID LEVEL ASCENT ASSOCIATED
WITH AN EWD ADVANCING SHORTWAVE TROUGH. GIVEN STRENGTH OF
INVERSION...IT IS UNLIKELY THAT STORMS WILL BE ABLE TO ROOT FARTHER
DOWN. STRENGTHENING SLY LOW LEVEL JET IS ENHANCING ISENTROPIC LIFT
IN FRONTAL ZONE...AND THIS MAY CONTRIBUTE TO SOME COOLING AND
MOISTENING IN THE INVERSION LAYER. HOWEVER...AT THIS TIME CONFIDENCE
IS NOT HIGH THAT INVERSION WILL BE ERODED SUFFICIENTLY FOR UPDRAFTS
TO TAP INTO HIGH THETA-E AIR BELOW 800 MB.

.DIAL.. 08/28/2007

..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MPX...FSD...ABR...LBF...

44849564 43359775 43009848 42969916 43519882 44629754
44979661

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