Severe Thunderstorm Warning 53, NWS Grand Rapids, MI

Area Forecast Discussion
National Weather Service Grand Rapids MI
738 PM EDT Fri Apr 17 2026

.KEY MESSAGES...

- Line of Storms Crosses Area Tonight, Strong to Severe Possible

- Cooler Sunday, Drier Pattern Ahead

&&

.DISCUSSION...
Issued at 253 PM EDT Fri Apr 17 2026

- Line of Storms Crosses Area Tonight, Strong to Severe Possible

Storms out west across the upper Mississippi Valley will traverse
east through the evening reaching the lakeshore near 9am. HREF/RAP
guidance is less bullish on CAPE than yesterday with MUCAPE on the
order of 500-1000 J/kg by the time storms arrive thanks to a warm
nose just off the surface. 30-45 knots of deep layer, and 0-3 km
shear will be sufficient for the potential of storms remaining
organized as they approach. Damaging winds in any bowing segments
are the main concern, with a non-zero, but low, risk of tornadoes.
The greatest risk will be near and west of US131 where the
earlier arrival will support better instability lessening with
eastward extent. Showers and garden variety storms will follow the
primary line continuing through daybreak. Widespread rainfall of
0.25-0.75" is expected with isolated totals to around 1.5 inches.
The progressive nature of the storms should limit areal flooding
concerns but any training or heavier swaths will bring that
potential given saturated soils.

- Cooler Sunday, Warmer and Drier Pattern Next Week

Colder air filters in behind the cold front with 850mb temps falling
into the negatives. This will also support breezy conditions later
Saturday with gusts to 30-35 mph. Highs in the 40s and lows in the
20s to low 30s between Sunday Morning and Monday will be a notable
change from recent patterns. The bright side is the incoming ridging
and northwest flow will be much drier than we have been of late. Dry
weather is likely until late next week when the approach of our next
system brings precipitation back into the forecast. Temperatures
then rebound into the 60s and 70s.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 738 PM EDT Fri Apr 17 2026

Thunderstorms from the west will move east tonight from 01Z to 08Z
from west to east. Thunderstorms may contain gusts 25 to 35 knots
with higher gusts possible for the western TAF sites. MVFR
ceilings move in with the thunderstorms and may fall to IFR levels
briefly into Saturday morning. Low visibilities of 1 to 3 SM are
also likely with heavy rain.

Low level wind shear of 40 to 50 knots will also be present as
the low level jet from 03 to 12Z Saturday.

Northwest winds behind the front Saturday will build through the
day with gusts 25 to 30 knots. Ceilings will also begin to lift
and scatter out Saturday afternoon and evening.

&&

.MARINE...
Issued at 253 PM EDT Fri Apr 17 2026

Webcams show that fog has dissipated across the nearshore waters
so will be ending the Marine Dense Fog advisory with this package.
Winds and waves increase to levels hazardous to small craft
tonight and continue through the weekend. A Small Craft Advisory
goes into effect this evening continuing into Sunday. A line of
thunderstorms is expected to cross the lake this evening. Wind
gusts to 34 knots are possible as this line moves through.

&&

.HYDROLOGY...
Issued at 253 PM EDT Fri Apr 17 2026

Major flooding continues on the Muskegon River. The good news is
that the river at most locations will be cresting within the next 24
hours (Upstream areas of the river including Evart crested earlier
today). It will likely take until late next week for all locations
to come under flood stage, so the recovery process will be slow.
Meanwhile, water levels continue to rise on the Grand River, and
confidence is increasing that this will end up being another minor
flood event, slightly higher and worse than the one that happened
earlier this month, but not a record flood at any locations.
However, some of the lowest and easily flooded locations on the
river like Comstock Park and Robinson Township will have moderate to
possibly major flooding.

A final round of rain moves back into Lower Michigan tonight, and is
expected to drop around one-half inch of rain over a large area,
with locally higher streaks of 1"+ possible at some locations. Given
the saturated soils everywhere, this could result in some renewed
minor flooding, primarily impacting roadways. Thankfully, this
expected rainfall is not anticipated to make the river flooding
significantly worse at any locations. Beyond this next round of
rain, we dry out for at least the better part of a week going
forward, which will be a very welcome chance for the rivers to begin
the slow process of recovering to more normal levels.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 8 AM EDT Sunday for LMZ844>849.

&&

DISCUSSION...Thomas
AVIATION...RAH
MARINE...Thomas
HYDROLOGY...AMD

Hazardous Weather Outlook
National Weather Service Grand Rapids MI
247 PM EDT Fri Apr 17 2026

MIZ037>040-043>046-050>052-056>059-064>067-071>074-181900-
Mason-Lake-Osceola-Clare-Oceana-Newaygo-Mecosta-Isabella-Muskegon-
Montcalm-Gratiot-Ottawa-Kent-Ionia-Clinton-Allegan-Barry-Eaton-
Ingham-Van Buren-Kalamazoo-Calhoun-Jackson-
247 PM EDT Fri Apr 17 2026

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

.DAY ONE...This Afternoon and Tonight

Strong to severe storms will be possible this evening into early
tomorrow. Damaging winds and large hail are the main threat

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this evening.

LMZ844>849-181900-
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-
247 PM EDT Fri Apr 17 2026

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

.DAY ONE...This Afternoon and Tonight

Thunderstorms will be possible tonight into tomorrow. Winds in
excess of 34 knots are possible in the strongest storms. Small
craft advisory is in effect tonight through the weekend.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Small craft advisory conditions will continue Saturday into
Sunday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

Special Weather Statement
National Weather Service Grand Rapids MI
1201 AM EDT Sat Apr 18 2026

MIZ056-180445-
Ottawa MI-
1201 AM EDT Sat Apr 18 2026

...Strong thunderstorms will impact portions of Ottawa County through
1245 AM EDT...

At 1201 AM EDT, Doppler radar was tracking showers and thunderstorms
along a line extending from near Grand Haven to 6 miles northwest of
Zeeland to near Beechwood. Movement was northeast at 50 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...
Holland...             Grand Haven...         Walker...
Grandville...          Hudsonville...         Zeeland...
Coopersville...        Ferrysburg...          Spring Lake...
Beechwood...           Jenison...             Allendale...
Conklin...             Wright...              Port Sheldon...
Borculo...             Crockery Lake...       Lamont...
Olive Center...        Eastmanville...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4312 8621 4312 8591 4320 8591 4320 8579
      4289 8578 4277 8603 4277 8616 4285 8614
      4292 8622 4298 8622 4309 8625
TIME...MOT...LOC 0401Z 232DEG 43KT 4301 8621 4290 8608 4280 8610

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

NJJ