Alert archive / Michigan / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 63, NWS Grand Rapids, MI

May 18, 20264 counties in Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at May 18, 2026, 2:34 PM EDT for 4 counties in Michigan. It was in force for 70 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 18, 2026, 2:34 PM EDT (18:34 UTC)
Expired: May 18, 2026, 3:44 PM EDT
In force: 70 min
Issued by: NWS Grand Rapids, MI
Area: Storm-based polygon
Damage threat: Considerable
Hail: 0.75 in
Wind: 70.0 mph

Counties Calhoun County, MI, Eaton County, MI, Ionia County, MI, Montcalm County, MI

The radar

The Grand Rapids radar (KGRR), 45 km from the middle of the area, began a volume at 18:36 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 18, 12:59 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 6.6 hours before the alert went out and 130 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 97 J/kg
Mixed-layer CIN: -412 J/kg
Mixed-layer LCL: 1455 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 15 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Grand Rapids, MI wrote its last area forecast discussion before this severe thunderstorm warning went out at May 18, 2:15 PM EDT, 19 minutes earlier.

Area forecast discussion, May 18, 2:15 PM EDT, 19 minutes before

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In the hours before

Special weather statement, May 18, 12:46 PM EDT, 1 hour 48 minutes before

Special Weather Statement
National Weather Service Grand Rapids MI
1246 PM EDT Mon May 18 2026

MIZ037-038-043-044-181745-
Oceana MI-Lake MI-Newaygo MI-Mason MI-
1246 PM EDT Mon May 18 2026

...Strong thunderstorms will impact portions of northwestern
Newaygo, northeastern Oceana, Lake, and Mason Counties through 145
PM EDT...

At 1245 PM EDT, Doppler radar was tracking developing thunderstorms
from around Free Soil to Custer to 10 miles north of Hesperia.
Movement was northeast at 50 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Baldwin...             Scottville...          Luther...
Fountain...            Free Soil...           Colfax...
Custer...              Walkerville...         Woodland Park...
Nirvana...             Big Star Lake...       Wolf Lake...
Idlewild...            Irons...               Walhalla...
Bristol...             Sauble Lakes...        Bitely...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, seek shelter inside a building.

&&

LAT...LON 4416 8598 4417 8557 4398 8556 4365 8590
      4359 8600 4358 8609 4386 8624 4406 8640
      4418 8635
TIME...MOT...LOC 1643Z 210DEG 45KT 4404 8635 4390 8622 4371 8610

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

CAS

Local storm report, May 18, 1:49 PM EDT, 45 minutes before

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Local storm report, May 18, 1:53 PM EDT, 41 minutes before

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Local storm report, May 18, 2:15 PM EDT, 19 minutes before

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Local storm report, May 18, 2:29 PM EDT, 5 minutes before

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The office that day

Everything else NWS Grand Rapids, MI issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 18, 4:01 AM EDT	Small Craft Advisory	GRR		42 hr
May 18, 12:30 PM EDT	Special Marine Warning	GRR		103 min
May 18, 12:46 PM EDT	Special Weather Statement	GRR	Lake	59 min
May 18, 1:20 PM EDT	Severe Thunderstorm Warning	GRR	Allegan, Van Buren	55 min
May 18, 1:58 PM EDT	Severe Thunderstorm Warning	GRR	Allegan, Barry, Calhoun, Kalamazoo, Kent, Ottawa	79 min
May 18, 2:24 PM EDT	Severe Thunderstorm Warning Destructive damage threat	GRR	Allegan, Barry, Kent	36 min
May 18, 2:59 PM EDT	Severe Thunderstorm Warning Destructive damage threat	GRR	Clinton, Eaton, Ingham, Ionia	46 min
May 18, 3:07 PM EDT	Severe Thunderstorm Warning Considerable damage threat	GRR	Clinton, Gratiot, Ingham, Isabella, Jackson	53 min
May 18, 3:55 PM EDT	Severe Thunderstorm Warning	GRR	Ingham, Jackson	35 min
May 18, 4:00 PM EDT	Severe Thunderstorm Warning	GRR	Clare, Isabella	30 min

Nearby

Severe Thunderstorm Warnings in Michigan, 2026 Every severe thunderstorm warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.