118
ACUS11 KWNS 090740
SWOMCD
SPC MCD 090740
MNZ000-WIZ000-IAZ000-090915-
MESOSCALE DISCUSSION 1908
NWS STORM PREDICTION CENTER NORMAN OK
0240 AM CDT SAT AUG 09 2025
AREAS AFFECTED...PORTIONS OF MN INTO NORTHWEST WI AND IA
CONCERNING...SEVERE THUNDERSTORM WATCH 578...
VALID 090740Z - 090915Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 578
CONTINUES.
SUMMARY...ISOLATED TO WIDELY SCATTERED STORMS MAY PRODUCE STRONG TO
SEVERE WIND GUSTS INTO EARLY MORNING ACROSS EASTERN PORTIONS OF
MINNESOTA, NORTHWEST WISCONSIN, AND PORTIONS OF NORTHERN IOWA.
DISCUSSION...STORMS HAVE MODESTLY INCREASED IN COVERAGE/INTENSITY
OVER THE PAST 1-2 HOURS AHEAD OF THE EAST/SOUTHEAST-ADVANCING COLD
FRONT. A VERY MOIST AIRMASS BENEATH STEEP MIDLEVEL LAPSE RATES IS
SUPPORTING A CORRIDOR OF STRONG INSTABILITY GREATER THAN 2500 J/KG.
STRONGER VERTICAL SHEAR LAGS SOMEWHAT BEHIND THE FRONT ACROSS IA
INTO SOUTHEAST MN/NORTHWEST WI, BUT A 30-40 KT LOW-LEVEL JET IS
EVIDENT ACROSS THE REGION. CONVECTION HAS BEEN SOMEWHAT SLOW TO
INCREASE/ORGANIZE, BUT WILL LIKELY PERSIST IN THE FAVORABLE
THERMODYNAMIC ENVIRONMENT AS LARGE-SCALE ASCENT CONTINUES TO SLOWLY
OVERSPREAD THE MID-MO/UPPER MS VALLEYS INTO EARLY MORNING. DAMAGING
WIND GUSTS WILL BE THE MAIN HAZARD WITH THIS ACTIVITY, THOUGH
ISOLATED LARGE HAIL IS POSSIBLE WITH ANY MORE DISCRETE CELLULAR
ACTIVITY.
SEVERE THUNDERSTORM WATCH 578 IS SET TO EXPIRE AT 09Z. GIVEN
CONVECTION IS LIKELY TO PERSIST, A LOCAL WATCH EXTENSION OR A NEW
WATCH ISSUANCE IS POSSIBLE FOR PARTS OF THE MCD AREA.
..LEITMAN.. 08/09/2025
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...DLH...ARX...MPX...DMX...FSD...
LAT...LON 42509608 48589323 48238987 45549139 42559354 42509608
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
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