Severe Thunderstorm Warning 35, NWS Grand Rapids, MI

Area Forecast Discussion
National Weather Service Grand Rapids MI
313 PM EDT Wed Jun 18 2025

.KEY MESSAGES...

- Severe storms this afternoon/evening

- Precipitation chances continue Thursday night into Friday

- Hot weather begins Saturday

&&

.DISCUSSION...
Issued at 313 PM EDT Wed Jun 18 2025

- Severe storms this afternoon/evening

Mesoscale Convective Vortex (MCV) currently crossing central IL
is the feature to watch. There is a growing rain shield developing
northeast of this low and that is likely more elevated in nature.
The MCV is expected to progress into Indiana and we will see a
peripheral threat for severe weather across our southern forecast
area particularly along the I-94 corridor where all threats are in
play, mainly between 4 and 10 PM.

There is a short fused hydro threat as well. Impressive rain totals
already have been observed across SE Lower MI and there is a
Mesoscale Precipitation Discussion (#0478) issued by WPC that
discusses the flood threat for southwest Lower MI as well. Please
refer to this product for further details.

- Precipitation chances continue Thursday night into Friday

As noted previously, we can expect wrap around precipitation
continuing overnight and at least into the first part of Thursday.
Areas south of I-96 could be dry by Thursday afternoon. However,
father north more towards US-10, there will be a persistent surface
trough juxtaposed with persistent conditional instability and
episodic weak upper PV advection in northwest flow. This justifies
continued PoPs, primarily north of I-96.

- Hot weather begins Saturday

Upper ridging becomes especially pronounced by Saturday with
attendant mid-level warming/capping. Sunday and Monday will likely
feature surface dewpoints in the lower 70s combined with highs in
the lower/mid 90s under clear skies. This will yield apparent
temperatures in excess of 100 both days. As noted previously, there
is a signal for a cold front to ease the situation in the late
Tuesday/Wednesday timeframe, but the forcing for this is
questionable. Therefore, it's quite plausible that oppressive
conditions will persist into Wednesday and beyond.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 130 PM EDT Wed Jun 18 2025

No substantial changes to previous thinking. We are awaiting the
arrival of storms currently over northern Illinois moving northeast.
Convective wind gusts with the activity could be quite strong for
terminals along the I-94 corridor (AZO-BTL-JXN), with a lesser
threat farther north. Winds in general will be rather variable in
direction across the area with a gradual veering trend as a compact
surface low moves northeast into southwest Lower MI and exits early
tonight.

MVFR/IFR with even brief LIFR restrictions will be commonplace even
after thunderstorms pass early tonight. This will be due to a
combination of low ceilings and some fog development thanks to light
winds and substantial humidity resulting from prior rainfall.
Although not specifically mentioned in the terminals for the same of
brevity, there is a good chance for fuel alternate MVFR cigs to
persist well after 12Z Thursday with continued attendant showers.

&&

.MARINE...
Issued at 313 PM EDT Wed Jun 18 2025

No headline concerns at this time. A surface low will pass east of
the waters, allowing for a brief period of northwest winds tonight.
However both the speed and duration will be limited and this will
curtail wave growth. The next appreciable chance for marine
headlines at this stage looks like Friday night where we will see
a response to the effects of persistent southerly flow.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

DISCUSSION...TJT
AVIATION...TJT
MARINE...TJT

Hazardous Weather Outlook
National Weather Service Grand Rapids MI
540 AM EDT Wed Jun 18 2025

MIZ037>040-043>046-050>052-056>059-064>067-071>074-190945-
Mason-Lake-Osceola-Clare-Oceana-Newaygo-Mecosta-Isabella-Muskegon-
Montcalm-Gratiot-Ottawa-Kent-Ionia-Clinton-Allegan-Barry-Eaton-
Ingham-Van Buren-Kalamazoo-Calhoun-Jackson-
540 AM EDT Wed Jun 18 2025

This hazardous weather outlook is for portions of southwest Lower
Michigan.

.DAY ONE...Today and Tonight

Thunderstorms will be possible off and on through this evening.
Storms are not expected to be severe this morning. The potential
for storms to become severe will increase this afternoon, with the
highest potential between 2 pm and 8 pm. Areas south of Interstate
96 will have the best chance of severe weather. The main threat
will be strong winds, with a smaller chance of large hail, and
an isolated tornado.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

There is a small chance of a storm late Thursday afternoon. Severe
weather is not expected.

Hot and humid conditions will develop this weekend and continue
into early next week. This could case heat related issues for
vulnerable populations.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be possible late this afternoon and
evening, especially south of I-96.

LMZ844>849-190945-
St Joseph to South Haven MI-South Haven to Holland MI-
Holland to Grand Haven MI-Grand Haven to Whitehall MI-
Whitehall to Pentwater MI-Pentwater to Manistee MI-
540 AM EDT Wed Jun 18 2025

This hazardous weather outlook is for the nearshore waters from
St Joseph to Manistee.

.DAY ONE...Today and Tonight

Thunderstorms will be possible off and on through this evening.
Storms are not expected to be severe this morning. The potential
for storms to become severe will increase this afternoon, with the
highest potential between 2 pm and 5 pm. Areas south of
Muskegon will have the best chance of severe weather. The main threat
will be strong winds, with a smaller chance of large hail, and
an isolated waterspout.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

There is a small chance of a storm late Thursday afternoon. Severe
weather is not expected.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be possible late this afternoon and
evening, especially south of I-96.

Special Weather Statement
National Weather Service Grand Rapids MI
431 PM EDT Wed Jun 18 2025

MIZ071-072-182130-
Kalamazoo MI-Van Buren MI-
431 PM EDT Wed Jun 18 2025

...Strong thunderstorms will impact portions of Van Buren and western
Kalamazoo Counties through 530 PM EDT...

At 430 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Bridgman to near Niles. Movement was
northeast at 45 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

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

Locations impacted include...
Kalamazoo...           Portage...             South Haven...
Paw Paw...             Vicksburg...           Hartford...
Mattawan...            Lawton...              Bangor...
Decatur...             Schoolcraft...         Westwood...
Van Buren SP...        Lake Michigan Beach... Alamo...
Pine Grove...          Covert...              Keeler...
Lawrence...            Gobles...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
southwestern Michigan.

&&

LAT...LON 4207 8622 4224 8622 4224 8637 4235 8630
      4241 8628 4242 8576 4218 8544 4207 8539
TIME...MOT...LOC 2030Z 220DEG 38KT 4196 8653 4178 8615

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

CAS