602
ACUS11 KWNS 041911
SWOMCD
SPC MCD 041910
WIZ000-ILZ000-IAZ000-MNZ000-042115-
MESOSCALE DISCUSSION 2234
NWS STORM PREDICTION CENTER NORMAN OK
0210 PM CDT FRI SEP 04 2026
AREAS AFFECTED...NORTHERN IOWA INTO SOUTHERN WISCONSIN
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 041910Z - 042115Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...ISOLATED INSTANCES OF HAIL AND GUSTY WINDS POSSIBLE THIS
AFTERNOON.
DISCUSSION...CONVECTION HAS DEVELOPED ACROSS CENTRAL/NORTHERN IOWA
NEAR A ZONE OF WEAK SURFACE CONVERGENCE AND ALONG A SURFACE BOUNDARY
DRAPED ACROSS NORTHERN IOWA INTO SOUTHERN WISCONSIN. WATER VAPOR
IMAGERY SHOWS THIS MADE BE AIDED BY WEAK ASCENT WITH A SHORTWAVE
MOVING ACROSS THE REGION. A BROAD AREA OF STRONG INSTABILITY EXTENDS
ALONG AND SOUTH OF THE SURFACE BOUNDARY ACROSS IOWA AND SOUTHERN
WISCONSIN/NORTHERN ILLINOIS. THIS WAS WELL SAMPLED BY THE 18Z RAOB
FROM DVN, WHICH SHOWS AROUND 3400 J/KG MLCAPE. DEEP LAYER FLOW IS
FAIRLY WEAK ACROSS IOWA, WITH MORE FAVORABLE FLOW/DEEP LAYER SHEAR
LOCATED ALONG AND NORTH OF THE SURFACE BOUNDARY. ADDITIONALLY,
SURFACE OBJECTIVE ANALYSIS SUGGESTS MLCIN REMAINS FAIRLY STRONG
ACROSS THE REGION. THE 18Z RAOB FROM DVN ALSO SUGGESTS TEMPERATURES
ALOFT ARE QUITE WARM, GIVEN THE UPPER-LEVEL RIDGE INFLUENCE. IT IS
LIKELY THAT CONVECTION WILL REMAIN FAIRLY ISOLATED AND POSSIBLE
SHORT-LIVED BUT A FEW INSTANCES OF MARGINALLY SEVERE HAIL AND WIND
WILL BE POSSIBLE.
..THORNTON/GUYER.. 09/04/2026
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...LOT...MKX...DVN...ARX...DMX...
LAT...LON 43399220 43279283 43089331 42949365 42499398 42189387
42129370 42379134 42488905 42808879 43108892 43368930
43558976 43579107 43569127 43399220
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
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