Friday, May 25, 2007

MESO: Mesoscale Discussion 0888

ACUS11 KWNS 251845
SWOMCD
SPC MCD 251844
SDZ000-NDZ000-WYZ000-251945-

MESOSCALE DISCUSSION 0888
NWS STORM PREDICTION CENTER NORMAN OK
0144 PM CDT FRI MAY 25 2007

AREAS AFFECTED...NERN WY...NWRN SD...SWRN/SCNTRL ND

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 251844Z - 251945Z

CONDITIONS ARE BECOMING INCREASINGLY FAVORABLE FOR SEVERE STORM
DEVELOPMENT ACROSS PARTS OF THE DAKOTAS IN THE NEXT COUPLE OF HOURS.
A WATCH WILL LIKELY BE ISSUED SHORTLY FOR SECTIONS OF WRN
SD...SWRN/SCNTRL ND...AND PERHAPS ERN WY.

LATEST ANALYSIS INDICATED SURFACE LOW ACROSS NWRN SD WITH WARM FRONT
EXTENDING NEWD AND THEN EWD ALONG THE SD/ND BORDER AREA. COLD FRONT
APPEARS TO BE SWEEPING SEWD ACROSS NERN WY WITH WIDESPREAD CU
DEVELOPMENT OCCURRING ALONG AND AHEAD OF THIS FEATURE. WHILE AIR
MASS REMAINS DRY ACROSS WRN SD ATTM...SURFACE TEMPERATURES IN THE
MID 70S AND COOLING TEMPERATURES ALOFT WERE CONTRIBUTING TO MLCAPE
VALUES AROUND 1000 J/K IN THE WARM SECTOR ATTM. CONVERGENCE NEAR THE
SURFACE LOW AND WARM FRONT APPEAR SUFFICIENT TO INITIATE CONVECTION
SHORTLY AND...GIVEN EFFECTIVE SHEAR NEAR THESE FEATURES IN THE RANGE
OF 30-40 KT...A FEW SUPERCELLS WITH LARGE HAIL APPEAR POSSIBLE.
TORNADO THREAT WILL ALSO EXIST IF CELLS CAN TRACK PREFERENTIALLY
ALONG THE WARM FRONT WHERE A FOCUSED REGION OF STRONG LOW LEVEL SRH
WILL ENHANCE UPDRAFT ROTATION POTENTIAL. HOWEVER...GIVEN RELATIVELY
HIGH LFC DUE TO LIMITED MOISTURE ACROSS THE REGION...TORNADO
POTENTIAL WILL LIKELY REMAIN QUITE LIMITED IN TIME/SPACE.

ADDITIONAL HIGH-BASED ACTIVITY APPEARS LIKELY TO INCREASE AS THE
UPPER IMPULSE AND ASSOCIATED COLD FRONT SPREAD EAST FROM ERN WY OVER
THE NEXT FEW HOURS. DAMAGING WIND POTENTIAL MAY ACCOMPANY SOME OF
THIS CONVECTION. SHEAR ACROSS THE WARM SECTOR WILL INCREASE AS THE
UPPER SYSTEM SPREADS EWD THIS EVENING AND THIS COULD PROMOTE SOME
UPSCALE DEVELOPMENT LATER IN THE DAY WITH A SMALL ORGANIZED COMPLEX
OF STORMS SPREADING EWD ACROSS SD.

.CARBIN.. 05/25/2007

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

ATTN...WFO...ABR...BIS...UNR...CYS...

43670304 43350402 43970446 44980387 46010355 46510256
46690096 46239943 45629946 44890063

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