MESO: Mesoscale Discussion 1771

ACUS11 KWNS 252056
SWOMCD
SPC MCD 252055
WIZ000-MNZ000-252200-

MESOSCALE DISCUSSION 1771
NWS STORM PREDICTION CENTER NORMAN OK
0355 PM CDT SUN AUG 25 2013

AREAS AFFECTED...CNTRL MN...NWRN WI

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 252055Z - 252200Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THE POTENTIAL FOR CONVECTIVE INITIATION CONTINUES TO BE
MONITORED ACROSS CNTRL MN WITHIN THE NEXT 1-3 HRS. IF TSTMS
DEVELOP...A RISK FOR DMGG WINDS AND LARGE HAIL WILL LIKELY EXIST AND
MAY REQUIRE A WW.

DISCUSSION...VISIBLE SATELLITE LOOP SHOWS AN EXPANDING AREA OF
BOUNDARY LAYER CU INVOF A WEAKLY CONVERGENT BOUNDARY DRAPED ACROSS
W-CNTRL AND N-CNTRL MN. A SUBTLE UPSTREAM IMPULSE WAS ALSO NOTED
NEAR ABR...AND WILL INTERSECT THE BOUNDARY IN THE NEXT 1-2 HRS.
WHILE LARGE-SCALE FORCING FOR ASCENT REMAINS MINIMAL WITH
NEAR-NEUTRAL MIDLEVEL HEIGHT CHANGES...THE POTENTIAL FOR CONVECTIVE
INITIATION MAY INCREASE AS THE UPPER IMPULSE APPROACHES THE
AREA...AND TEMPERATURES HEAT INTO THE MID-90S F RESULTING IN
WEAKENING CINH. RICH BOUNDARY LAYER MOISTURE /SFC DEWPOINTS NEAR 70
F/ BENEATH STEEP MIDLEVEL LAPSE RATES IS CONTRIBUTING TO MLCAPE
VALUES NEAR 1000-2000 J/KG...WITH HIGHER CAPE VALUES FARTHER S INTO
S-CNTRL MN. VERTICAL WIND PROFILES ARE MARGINALLY FAVORABLE FOR
STORM ORGANIZATION INTO MULTICELL CLUSTERS OR PERHAPS TRANSIENT
SUPERCELL STRUCTURES. THE PRIMARY THREATS WILL BE LARGE HAIL AND
DMGG WINDS SHOULD TSTMS DEVELOP....EVENTUALLY SPREADING E OR SEWD
INTO PARTS OF E-CNTRL MN AND PERHAPS NWRN WI. CONVECTIVE TRENDS WILL
CONTINUE TO BE MONITORED FOR A POSSIBLE WW.

..ROGERS/THOMPSON.. 08/25/2013

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

ATTN...WFO...DLH...MPX...FGF...

LAT...LON 46449114 46019136 45849280 45749389 45809502 45989586
46319642 46819640 47409546 47589446 47549350 47399205
46449114

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