491
ACUS11 KWNS 141756
SWOMCD
SPC MCD 141756
WIZ000-ILZ000-IAZ000-MNZ000-142000-
MESOSCALE DISCUSSION 0419
NWS STORM PREDICTION CENTER NORMAN OK
1256 PM CDT TUE APR 14 2026
AREAS AFFECTED...PARTS OF CENTRAL/EASTERN IA...SOUTHERN WI...AND
NORTHERN IL
CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY
VALID 141756Z - 142000Z
PROBABILITY OF WATCH ISSUANCE...95 PERCENT
SUMMARY...THE RISK OF SUPERCELLS CAPABLE OF PRODUCING SEVERAL
TORNADOES (SOME STRONG TO INTENSE), GIANT HAIL, AND SEVERE WIND
GUSTS WILL INCREASE BY AROUND 19-22Z. A TORNADO WATCH IS LIKELY
WITHIN THE NEXT COUPLE HOURS.
DISCUSSION...THE LATEST SURFACE ANALYSIS DEPICTS A QUASI-STATIONARY
BOUNDARY EXTENDING FROM CENTRAL/NORTHERN IA INTO SOUTHERN/CENTRAL
WI, WITH AN ADDITIONAL COMPOSITE OUTFLOW BOUNDARY FARTHER SOUTH FROM
NORTHEAST IA INTO NORTHERN IL. OVER THE NEXT FEW HOURS, CONTINUED
DIURNAL HEATING OF A MOIST AIR MASS (UPPER 60S DEWPOINTS) SHOULD
ERODE REMAINING INHIBITION AT THE BASE A SUBSTANTIAL EML, RESULTING
IN THE DEVELOPMENT OF STRONG SURFACE-BASED BUOYANCY (UPWARDS OF
3000-3500 J/KG MLCAPE). AS THIS OCCURS, INITIAL THUNDERSTORM
DEVELOPMENT IS EXPECTED ACROSS PARTS OF CENTRAL/EASTERN IA NEAR THE
INTERSECTING BOUNDARIES BY AROUND 19-22Z -- AIDED BY A SUBTLE
FRONTAL WAVE TRACKING EASTWARD ALONG THE QUASI-STATIONARY BOUNDARY.
THE STRONGLY UNSTABLE AIR MASS COUPLED WITH 40-50 KT OF EFFECTIVE
SHEAR WILL FAVOR RAPID THUNDERSTORM ORGANIZATION/INTENSIFICATION
INTO SEMI-DISCRETE SUPERCELLS AND ORGANIZED CLUSTERS. INITIALLY,
VERY LARGE TO GIANT HAIL (2-3+ INCHES IN DIAMETER) AND SEVERE WIND
GUSTS WILL BE THE MAIN CONCERN WITH POTENTIALLY SPLITTING SUPERCELLS
-- GIVEN A MOSTLY STRAIGHT HODOGRAPH. HOWEVER, A SOUTH-SOUTHWESTERLY
LOW-LEVEL JET WILL STRENGTHEN ACROSS THE AREA LATER THIS AFTERNOON
INTO THE EVENING AND LIKELY FAVOR A TRANSITION TO DOMINANT
RIGHT-MOVING SUPERCELLS WITH A QUICKLY INCREASING TORNADO RISK. THE
STRONG BUOYANCY AND 200-300+ M2/S2 EFFECTIVE SRH WILL SUPPORT STRONG
TO INTENSE TORNADOES WITH ANY LONGER-LIVED SUPERCELLS, ALONG WITH A
CONTINUED RISK OF GIANT HAIL AND SEVERE GUSTS. EVENTUALLY,
THUNDERSTORMS MAY HAVE A TENDENCY OF GROWING UPSCALE INTO CLUSTERS
WITH EASTWARD EXTENT, WHICH WILL YIELD AN INCREASING RISK OF
DAMAGING WIND SWATHS.
A TORNADO WATCH WILL BE ISSUED WITHIN THE NEXT COUPLE HOURS.
..WEINMAN/GLEASON.. 04/14/2026
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...LOT...MKX...DVN...ARX...DMX...
LAT...LON 41219309 41419361 41849390 42349386 42679350 43349177
43819045 43798943 43548877 42948850 42438870 41938916
41309166 41219309
MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN
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