444
ACUS11 KWNS 171316
SWOMCD
SPC MCD 171316 COR
INZ000-ILZ000-IAZ000-MOZ000-171415-
MESOSCALE DISCUSSION 1162
NWS STORM PREDICTION CENTER NORMAN OK
0816 AM CDT WED JUN 17 2026
AREAS AFFECTED...EASTERN IOWA...FAR NORTHEAST MISSOURI...CENTRAL AND
NORTHERN ILLINOIS...FAR WESTERN INDIANA
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 171316Z - 171415Z
CORRECTED FOR WIND SPEEDS IN MOST PROBABLY PEAK INTENSITY ON GRAPHIC
PROBABILITY OF WATCH ISSUANCE...95 PERCENT
SUMMARY...SEVERE WIND GUSTS POTENTIALLY ABOVE 80 MPH, TORNADOES AND
ISOLATED LARGE HAIL WILL BE LIKELY THIS MORNING FROM EASTERN IOWA
SOUTHEASTWARD ACROSS NORTHWEST AND AND CENTRAL ILLINOIS. WEATHER
WATCH ISSUANCE IS EXPECTED ALONG THIS CORRIDOR.
DISCUSSION...RADAR IMAGERY SHOWS A WELL-DEVELOPED SEVERE BOWING LINE
SEGMENT ONGOING OVER EASTERN IOWA. THIS LINE WILL MOVE QUICKLY
SOUTHEASTWARD INTO NORTHWESTERN AND CENTRAL ILLINOIS THIS MORNING,
WHERE DAMAGING WIND GUSTS WILL BE LIKELY. THE LINE IS LOCATED NEAR
THE NOSE OF A STRONG LOW-LEVEL JET, WHICH WILL SHIFT EASTWARD INTO
WESTERN ILLINOIS OVER THE NEXT FEW HOURS. IN RESPONSE, THE BOWING
LINE SEGMENT IS EXPECTED TO BECOME VERY ORGANIZED AND WILL LAY DOWN
A SWATH OF WIND-DAMAGE ACROSS NORTHWEST AND CENTRAL ILLINOIS, WHERE
WIND GUSTS IN THE 80 TO 100 MPH RANGE WILL BE POSSIBLE. IN ADDITION,
RAP FORECAST SOUNDINGS INCREASE 0-3 KM STORM-RELATIVE HELICITY INTO
THE 400 TO 450 M2/S2 RANGE ACROSS WESTERN AND CENTRAL ILLINOIS BY
MID MORNING, SUGGESTING THAT A TORNADO THREAT WILL DEVELOP WITH THE
BOWING LINE SEGMENT. TORNADOES WILL BE POSSIBLE NEAR THE APEX OF THE
BOW, AND WITH ANY SUPERCELL EMBEDDED IN THE LINE. ISOLATED LARGE TO
VERY HAIL COULD ALSO OCCUR WITHIN THE MORE INTENSE CORES OF
SUPERCELLS.
..BROYLES/GUYER.. 06/17/2026
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...IND...LOT...ILX...LSX...DVN...DMX...
LAT...LON 39308747 39048810 39088873 39428972 39949092 40519207
40839246 41249260 41589250 41899226 42249172 42339108
41868958 41568894 40998785 40578738 40198717 39688722
39308747
MOST PROBABLE PEAK TORNADO INTENSITY...140-170 MPH
MOST PROBABLE PEAK WIND GUST...85-100 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN
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