Tornadoes and Damaging Winds in Illinois, June 3, 2025

Area Forecast Discussion
National Weather Service Quad Cities IA IL
559 AM CDT Tue Jun 3 2025

...12z Aviation Update...

.KEY MESSAGES...

-  Rounds of showers and thunderstorms still are in line for
   today, Some of the storms could become strong to severe
   especially south of I-80, along with swaths of heavy
   rainfall. The flooding threat should remain minimal, except
   if copious rainfall occurs over urban areas.

- Generally seasonal temps expected for most of the period into
  the weekend, with the next rain chances coming Thursday night
  into the start of the weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 315 AM CDT Tue Jun 3 2025

The current water vapor imagery loop was indicating the main
upstream weather maker upper wave acrs CO into northeast NM,
with progged mid level steering flow taking this feature right
acrs the DVN CWA by Wed morning. Upstream sfc front was
undulating from western LK Superior, down to Omaha, and to a sfc
wave to lee of upper low acrs far southeast CO into SW KS. With
pre- upper trof southwesterlies aligned with it as well as some
rippling sfc waves along it, this front to be a slow mover and
may not get much steam to become more progressive through the
CWA until after midnight into early Wed morning as the main
upper trof axis approaches from the west-southwest. Increasing
southwesterly low to mid level flow will be a warm moist
conveyor type shuttling PWAT's of 1.8 to over 2 inches up acrs
the region as the day progresses. The vertical wind fields are
robust for this time of year and produce deep layer of shear of
40-60 KTs by this afternoon and evening. Higher level clouds and
some lingering smoke aloft may limit higher CAPE values, but
with sfc DPTs well in the 60s if not near 70 pooling ahead of
the front, with some marginal heating there could be some areas
with values of effective CAPE of 1000-2000 J/kg especially south
of I-80.

Current short range/CAM guidance support the best combo of shear
and instability in our area of concern occurs by late afternoon into
early evening acrs the southeast quarter to third of the DVN CWA
(especially far southeast IA). All types of severe may occur here,
but thermal profiles and saturation may make it tough for severe
size hail to reach the sfc. Organized bowing segments with QLCS type
tornadoes possible southeast IA into west central IL 4-8 PM,
otherwise damaging wind gusts still seem to be the primary concern.
Secondary strong cells possible up closer to I-80 as well especially
along and east of the MS RVR this evening, while the northwest half
of the CWA may have more stratiform like rain with some embedded
thunder.

The models continue to advertise a high precipital water(PWAT) feed
of 1.8 to 2" inches, with the meso-analysis showing a pool of at
least 1.9 inches already upstream acrs east OK-KS. With the shear
and expected forcing, can expect swaths of matching rainfall
amounts of 1-2 inches by Wed morning, and would not be surprised
for a few 3 inch reports. Most of the area can take these amounts,
but potential high 2 inch an hour rainfall rates by passing storms
may produce some localized urban and small stream flooding/ponding
of low lying areas.

Post-frontal downward mixing mechanisms may finally allow for a
better chance for some wildfire smoke mix down to the sfc late
tonight in the northwestern CWA, but this is an uncertain call. But
upstream observations in MN show this ongoing with a lot of 3-5SM
visibility's. Post-frontal showers may linger in the east through
dawn Wed. Low temps ranging from the mid 50s northwest, to the low
60s east by 12z Wed.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 315 AM CDT Tue Jun 3 2025

Wednesday and Thursday...Will walk out a little lingering post-
frontal rain in the east Wed, and will have to assess the post-
frontal sfc smoke situation acrs the northwest half of the CWA for
air quality and vsby issues. Highs ranging from the upper 70s west
in earlier clear out zones, to the upper 60s/low 70s east. Broad mid
CONUS upper troffiness may try to produce spotty showers later Thu
and Thu night into Friday, but more of this period may be dry with
better/more organized precip support taking place to the south of
our area of concern. If mainly dry, Thu looks seasonable with highs
upper 70s to near 80 degrees.

Friday through Monday...Quick look at the extended suggests upper
troffiness to develop and dig south acrs the GRT LKS into the
weekend. We may just have spotty precip chances through this period
with near seasonable temps, or a day or two a bit below normal.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 555 AM CDT Tue Jun 3 2025

An approaching front and sfc wave will produce isolated to sctrd
showers and possibly some thunder moving through the TAF sites
through late morning, with some passing MVFR CIGs and VSBYs.
Then expect a midday to early afternoon lull in the precip
activity with varying MVFR to VFR CIGs with gusty south to
southwesterly sfc winds up to 28 KTs. Then will have to watch
for the main line or linear clusters of showers and
thunderstorms moving in from the west and southwest during the
mid afternoon through early evening period. The best bet for
strong to severe storms with high variable wind gusts appears to
be south of I-80 during the late afternoon into evening. There
will be a frontal passage wind shift(or storm outflow) to the
west during the evening, with moisture convergence supporting
low MVFR CIGs along and behind these frontal features. The
models are even more bullish now with IFR post-frontal CIGs
later tonight. Lighter rain could linger in spots well into
early Wed morning especially along and east of the MS RVR. Will
also have to watch for the possibility of post-frontal wildfire smoke
mixing down to the sfc and producing MVFR VSBY restrictions
late tonight into Wed morning especially at CID and DBQ.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.

&&

SHORT TERM...12
LONG TERM...12
AVIATION...12

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
446 AM CDT Tue Jun 3 2025

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-041100-
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-
Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll-
Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-Hancock-McDonough-Scotland-Clark-
446 AM CDT Tue Jun 3 2025

This Hazardous Weather Outlook is for portions of north central
Illinois...northwest Illinois...west central Illinois...east
central Iowa...northeast Iowa...southeast Iowa and northeast
Missouri.

.DAY ONE...TODAY AND TONIGHT

Occasional rounds of showers and thunderstorms are likely today and
tonight. The Storm Prediction Center has a Slight Risk (level 2
of 5) for severe storms generally south of Interstate 80. There is
a Marginal Risk (level 1 of 5) across the rest of the Outlook
Area. The main threat will be damaging winds, with an isolated
tornado a secondary concern. An increasingly humid air mass will
support heavy rainfall amounts of 1 to 2 inches, and isolated
higher amounts are possible. This may produce some urban and small
stream flooding, as well as ponding water in low-lying areas.

The pattern remains active for late in the week with a chance for
sporadic showers and thunderstorms from Thursday afternoon into
Friday. Severe weather is not anticipated at this time.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon and evening,
especially south of Interstate 80.

12

Special Weather Statement
National Weather Service Quad Cities IA/IL
943 AM CDT Tue Jun 3 2025

IAZ052-064-065-031530-
Linn IA-Cedar IA-Johnson IA-
943 AM CDT Tue Jun 3 2025

...A strong thunderstorm will impact portions of southeastern Linn,
northern Cedar and east central Johnson Counties through 1030 AM
CDT...

At 943 AM CDT, Doppler radar was tracking a strong thunderstorm over
Iowa City, moving northeast at 40 mph.

HAZARD...Winds in excess of 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could cause minor tree limb damage and blow
         around unsecured objects. Minor damage to outdoor objects
         is possible.

This strong thunderstorm will be near...
  West Branch around 950 AM CDT.

Other locations in the path of this storm include Mechanicsville and
Stanwood.

This includes Interstate 80 in Iowa between mile markers 245 and 254.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4195 9129 4195 9103 4188 9093 4158 9152
      4163 9158
TIME...MOT...LOC 1443Z 224DEG 33KT 4165 9149

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

JTS

Special Weather Statement
National Weather Service Quad Cities IA/IL
1147 AM CDT Tue Jun 3 2025

IAZ054-066-ILZ001-002-007-009-031730-
Whiteside IL-Carroll IL-Jo Daviess IL-Stephenson IL-Clinton IA-
Jackson IA-
1147 AM CDT Tue Jun 3 2025

...Strong thunderstorms will impact portions of northern Whiteside,
Carroll, Jo Daviess, Stephenson, northeastern Clinton and
southeastern Jackson Counties through 1230 PM CDT...

At 1146 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Council Hill to near Fulton. Movement was
east at 50 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could cause minor tree limb damage and blow
         around unsecured objects.

Strong thunderstorms will be near...
  Savanna, Elizabeth, Woodbine, Scales Mound, Massbach, Schapville,
  and Argo Fay around 1150 AM CDT.
  Mount Carroll, Stockton, Fairhaven, Chadwick, and Apple River
  around 1155 AM CDT.
  Lanark, Warren, and Coleta around 1200 PM CDT.
  Milledgeville, Pearl City, and Nora around 1205 PM CDT.

Other locations in the path of these storms include Lena, Shannon,
Freeport, Winslow and Cedarville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 4250 8940 4220 8940 4220 8969 4193 8969
      4193 8963 4183 8963 4179 9013 4251 9038
TIME...MOT...LOC 1646Z 258DEG 42KT 4248 9031 4188 9009

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

JTS