Hail in Illinois, April 22, 2025

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
Issued by National Weather Service Lincoln IL
309 PM CDT Tue Apr 22 2025

.KEY MESSAGES...

- Showers and thunderstorms continue to be in the forecast
  tonight, with a Marginal Risk for severe storms late this
  afternoon/this evening.

- Well above normal temperatures are expected inland through
  week's end, then turning more seasonable for the weekend.

- Chances for severe storms return early next week.

&&

.DISCUSSION...
Issued at 309 PM CDT Tue Apr 22 2025

Through Wednesday:

Zonal flow aloft exists across the area today, with upper level
lows across northern MN and Quebec currently. At the surface, a
warm front is lifting northeast across northern IL this
afternoon...ushering in warmer and more humid air into the
area. Expect showers and thunderstorms to move in/redevelop
across the forecast area by late afternoon. Believe the greatest
threat for storms in the Chicago metro to be from 6 pm to 8 pm
this evening. Instability (CAPE of near 1000 J/kg) and shear
(0-6 km bulk shear near 30 kts) will provide the risk for some
severe storms through this evening. The SPC currently has much
of LOT area in a Marginal Risk for tonight (except the SE).
Showers and isolated storms will be possible off and on through
the night across northern IL, with the best chance for a second
round from 3 am to 7 am.

For Wednesday, showers and storms will linger in the vicinity of
a boundary near the IL/WI border. Expect activity to be mostly
in WI, and generally, severe storms are not expected tomorrow.
However, some models have CAPEs near 1000 J/kg and deep shear at
25-30 kts, so it's not out of the question. Currently, northern
IL is not outlooked for severe weather by the SPC. Highs
tomorrow should be in the mid to upper 70s inland.

Knutsvig

Wednesday Night through Tuesday:

Warm temps will continue through the week with the next
weather-maker coming on Friday. Showers and isolated storms are
generally expected, with severe storms not expected currently.
After a return to cooler temperatures over the weekend, expect a
chance for severe storms possibly as early as Monday.

Knutsvig

&&

.AVIATION /18Z TAFS THROUGH 00Z THURSDAY/...
Issued at 107 PM CDT Tue Apr 22 2025

Forecast concerns for the terminals...

- Periods of scattered showers and thunderstorms from late this
  afternoon through early Wednesday morning.

- Breezy southwest winds this afternoon gusting 20-25 kt.

Shower/thunderstorm activity over southeast WI/far northeast IL
is anticipated to move off to the east, with a lull in storm
activity anticipated for much of the early to mid afternoon.
Scattered showers and storms ahead of a subtle wave moving
across IA are projected to arrive in northeastern IL/far
northwest IN later this afternoon. Confidence in coverage and
placement of lightning strikes is modest, but we should see an
increase in shower development in the 23z-01z time frame.

Confidence is low in exact placement of a west-east boundary
during the overnight and early morning hours which is
anticipated to act as a focus for shower and thunderstorm
development. In addition, some spread in timing of storm
development exists as well. We opted for a PROB30 group covering
the most likely early morning time frame for now, but some
adjustment in these times may occur.

Winds are anticipated to shift to a more south-southwesterly
direction through 19z, with some gusts up to 25 kt or so through
the afternoon. Look for southwesterly winds of 10 kt or less
this evening and overnight, becoming south-southeast in the
morning with gusty and erratic winds a possibility near
thunderstorms.

NWS Central IL

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

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Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
Issued by National Weather Service Lincoln IL
354 PM CDT Tue Apr 22 2025

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-232100-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-
La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-
Northern Cook-Central Cook-Southern Cook-Northern Will-
Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-Benton-
354 PM CDT Tue Apr 22 2025 /454 PM EDT Tue Apr 22 2025/

This Hazardous Weather Outlook is for portions of north central
Illinois...northeast Illinois and northwest Indiana.

.DAY ONE...Tonight.

Weather hazards expected...

  Limited Thunderstorm Risk...with an associated:
     Level 1 of 5 Damaging Wind Risk...up to 60 mph.
     Level 1 of 5 Large Hail Risk...up to 1 inch in diameter.

DISCUSSION...

Scattered thunderstorms are possible area wide late this
afternoon and tonight. One or two of any of the storms that form
this afternoon or tonight could become severe, posing a threat of
both damaging winds and large hail. Based on the latest
information, any severe threat this afternoon and tonight is
expected to remain quite isolated in nature.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Wednesday through Friday...
Limited Thunderstorm Risk.

Monday and Tuesday...
Limited Thunderstorm Risk.

DISCUSSION...

The best chance for storms will be in the north on Wednesday and
area-wide on Friday. The better chance for severe weather will
come early next week. But plenty of uncertainty remains for this
period.

.SPOTTER INFORMATION STATEMENT...

Due to the isolated nature of any severe weather, spotter
activation is not anticipated. However, spotters should relay any
reports of hail or damaging winds.

GENERAL STORM MOTION OF THE DAY:

 Moving toward the east at 35 mph.

LMZ740>745-232100-
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
354 PM CDT Tue Apr 22 2025

This Hazardous Weather Outlook is for portions of the Illinois
nearshore waters of Lake Michigan and the Indiana nearshore
waters of Lake Michigan.

.DAY ONE...Tonight.

Weather hazards expected...

  Limited Thunderstorm Risk...with an associated:
    Level 1 of 5 Thunderstorm Wind Gust Risk...up to 50 knots.
    Level 1 of 5 Hail Risk...up to 1 inch in diameter.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Wednesday...
  Limited Thunderstorm Risk.
Friday...
  Hazardous conditions for small craft are likely.
  Limited Thunderstorm Risk.
Saturday...
  Hazardous conditions for small craft are likely.

Visit us at www.weather.gov/chicago

Special Weather Statement
National Weather Service Chicago/Romeoville
Issued by National Weather Service Milwaukee/Sullivan WI
604 PM CDT Tue Apr 22 2025

ILZ008-222345-
Ogle IL-
604 PM CDT Tue Apr 22 2025

...A strong thunderstorm will impact portions of southeastern Ogle
County through 645 PM CDT
...

At 602 PM CDT, a strong thunderstorm was reported over mainly rural
areas of Ogle County moving east at 30 mph.

HAZARD...Penny size hail.

SOURCE...Doppler Radar.

IMPACT...Minor hail damage possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

&&

LAT...LON 4205 8950 4215 8897 4215 8894 4190 8894
      4192 8952
TIME...MOT...LOC 2302Z 263DEG 27KT 4201 8938

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...<30 MPH

MG