MESO: Mesoscale Discussion 1696

ACUS11 KWNS 222246
SWOMCD
SPC MCD 222246
MNZ000-SDZ000-NDZ000-230015-

MESOSCALE DISCUSSION 1696
NWS STORM PREDICTION CENTER NORMAN OK
0546 PM CDT FRI JUL 22 2011

AREAS AFFECTED...NE SD...SE ND AND WRN MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 222246Z - 230015Z

A SEVERE THREAT IS LIKELY TO DEVELOP ACROSS NERN SD...SE ND AND WRN
MN EARLY THIS EVENING. AN ISOLATED TORNADO THREAT ALONG WITH A
POTENTIAL FOR LARGE HAIL AND WIND DAMAGE WILL LIKELY EXIST ACROSS
THE MCD AREA. WW ISSUANCE WILL BE POSSIBLE ACROSS THE REGION.

ISOLATED THUNDERSTORMS ARE INITIATING IN NERN SD ALONG THE NRN EDGE
OF AN AXIS OF STRONG INSTABILITY WHERE MESOANALYSIS INDICATES MLCAPE
VALUES ARE IN THE 2500 TO 3500 J/KG RANGE. THE STORMS ARE INITIATING
ALONG A WELL-DEFINED FRONTAL BOUNDARY WHERE LOW-LEVEL CONVERGENCE IS
ENHANCED. THE ABERDEEN WSR-88D VWP SHOWS ABOUT 40 KT OF DEEP LAYER
SHEAR SUGGESTING SUPERCELL DEVELOPMENT WILL BE POSSIBLE WITH THE
ONGOING CONVECTION. A THREAT FOR LARGE HAIL WILL LIKELY EXIST
ESPECIALLY FROM ABERDEEN WWD WHERE SOME SHORT-TERM MODEL FORECASTS
INITIATE NEW CELLS ALONG THE FRONTAL BOUNDARY EARLY THIS EVENING AND
MID-LEVEL LAPSE RATES ARE STEEPER THAN AREAS TO THE EAST. AN
ISOLATED TORNADO THREAT MAY ALSO DEVELOP AS LOW-LEVEL FLOW INCREASES
EARLY THIS EVENING. IN ADDITION...THE STORMS ARE LOCATED IN A VERY
MOIST ENVIRONMENT WITH MID 70S F DEWPOINTS LOCATED ACROSS NERN SD
WHICH MAY AID A POTENTIAL FOR WET DOWN BURSTS.

..BROYLES.. 07/22/2011

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

ATTN...WFO...MPX...FGF...FSD...ABR...BIS...

LAT...LON 45520049 45120049 44769988 44529795 44709675 45129602
45869560 46899653 46969852 46749949 46409996 46050020
45520049

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