Special Weather Statement, NWS Grand Rapids, MI

Area Forecast Discussion
National Weather Service Grand Rapids MI
755 PM EDT Sat Aug 28 2021

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 232 PM EDT Sat Aug 28 2021

- Severe weather risk through Sunday

- Less humid weather early next week

&&

.DISCUSSION...(This evening through next Saturday)
Issued at 232 PM EDT Sat Aug 28 2021

- Severe weather risk through Sunday

The atmosphere is very unstable this afternoon and an MCV is
tracking eastward through Northern Lower MI at this time.  Storms
have developed closer to the track of the MCV.  Effective deep layer
shear is elevated south of this MCV. A few showers did start to
develop around Muskegon...they weakened. Additions showers are
trying to develop around Manitowoc...which could track into
Northwest parts of the CWA if they survive. Through sunset it looks
possible for an isolated severe thunderstorm...mainly north of a
Muskegon to Alma line. Later tonight a stronger low level jet forms
upstream in WI which then tracks into Northern Lower MI.  The
current thinking is that the main area of convection with this low
level jet stays north of the CWA. If the low level jet sets up
further south...we could see the stronger convection rolling into
our CWA...again later tonight.  Will need to monitor trends
closely.

On Sunday the cold front pushes through from the northwest.  It will
be warm and unstable as this front moves in. This will result in a
broken line of showers and thunderstorms developing. The mid level
low in Ontario will be tracking northeast and we see only slight
height falls at that level. Thus the more favorable dynamics will
be to the northeast of Lower MI. The mid level wind fields do
strengthen...which will support gusty winds with any stronger
storms. The stronger deep layer shear is shown to be lagging
behind the surface front...which would limit the organized
convective risk along the front here in MI Sunday afternoon.

- Less humid weather early next week

The PWAT values fall off considerably for Monday as the front
stalls out south of the CWA. The front is expected to remain south
of the CWA through Wednesday as a deeper northwest flow tries to
set up. Thus...much less in the way of humidity will be around. In
addition the temperatures will trend toward more seasonable values
for this time of the year.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 755 PM EDT Sat Aug 28 2021

Overall VFR conditions are expected through Sunday. Having said
that we do have a back building line of thunderstorms from near
Alma to north of Lansing to south of GRR. The storms are on the
boundary that separate the low level air coming off Lake Michigan
(more stable) from the air that did not cross Lake Michigan (more
unstable). Over the next hour I expect that line to fill in and
become nearly solid just north of Lansing. Once the sun sets, the
storms should come to an end, which would mean the I-94 TAF sites
would not be impacted. We will continue to monitor this and if it
seems the storms will impact these sites the TAFs will get
updated.

There has been a cluster of storms over Lake Michigan that keep
dissipating over mid-lake. I have VCTS MKG for 2 hours just in
case one of the these storms does make it across the lake.

It should be quite overnight once these storms do dissipate. We
will have to watch the line of storms with the cold front Sunday
during the late afternoon. I put VCTS for all our TAF sites since
I do believe these storms have a good chance of impacting all of
our TAF sites.

&&

.MARINE...
Issued at 232 PM EDT Sat Aug 28 2021

Southwest winds will increase tonight into Sunday as the cold
front moves in. This will increase the waves to up over 3 feet.
The longer fetch will favor the region from Holland then to the
north for the biggest waves. Some values over 5 feet look likely. The
south sides of the piers will be impacted up and down the
lakeshore. Given the warm water an increased numbers of swimmers
may try to enter the water...which would increase the risk. We
already issued the beach hazards so warn of the situation.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement from 6 AM EDT Sunday through Sunday
     evening for MIZ037-043-050-056-064-071.

     Heat Advisory until 8 PM EDT this evening for MIZ037>040-043>046-
     050>052-056>059-064>067-071>074.

LM...Small Craft Advisory from 2 AM to 10 PM EDT Sunday for
     LMZ844>849.

&&

SYNOPSIS...MJS
DISCUSSION...MJS
AVIATION...WDM
MARINE...MJS

Hazardous Weather Outlook
National Weather Service Grand Rapids MI
1130 AM EDT Sat Aug 28 2021

MIZ037>040-043>046-050>052-056>059-064>067-071>074-290930-
Mason-Lake-Osceola-Clare-Oceana-Newaygo-Mecosta-Isabella-Muskegon-
Montcalm-Gratiot-Ottawa-Kent-Ionia-Clinton-Allegan-Barry-Eaton-
Ingham-Van Buren-Kalamazoo-Calhoun-Jackson-
1130 AM EDT Sat Aug 28 2021

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

.DAY ONE...This Afternoon and Tonight

A Heat Advisory remains in effect for this afternoon as heat index
values of around 100 degrees are predicted.

A few thunderstorms are possible this afternoon and evening.  A
marginal risk for severe weather exists...mainly to the north of a
Muskegon to Alma line.  Damaging winds are the primary risk.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

A line of thunderstorms, a few of which could be strong to severe,
is looking likely Sunday afternoon and evening. Strong wind gusts
and hail are the main threats.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed Sunday afternoon and evening.

LMZ844>849-290930-
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-
1130 AM EDT Sat Aug 28 2021

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

.DAY ONE...This afternoon and Tonight

A moderate risk for hazardous swim conditions exists this afternoon.

A few thunderstorms are possible this afternoon and evening. Locally
gusty winds and frequent lightning are possible.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Stronger thunderstorms are possible along a cold front Sunday
afternoon and evening. Gusty winds and hail are the primary
threats.

Dangerous swim conditions are predicted for Sunday.  Conditions will
be hazardous for small craft as well.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed Sunday afternoon and evening.

Special Weather Statement
National Weather Service Grand Rapids MI
543 PM EDT Sat Aug 28 2021

MIZ052-282245-
Gratiot MI-
543 PM EDT Sat Aug 28 2021

...A strong thunderstorm will impact portions of northern Gratiot
County through 645 PM EDT...

At 542 PM EDT, Doppler radar was tracking a strong thunderstorm near
Breckenridge, or 11 miles northeast of Alma, moving east at 35 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Alma...                St. Louis...           Breckenridge...
Wheeler...             Forest Hill...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

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

&&

LAT...LON 4331 8448 4336 8474 4346 8475 4347 8472
      4346 8437 4331 8437
TIME...MOT...LOC 2142Z 260DEG 29KT 4345 8446

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

JC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
626 PM EDT SAT AUG 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0613 PM     HAIL             2 S SAINT LOUIS         43.38N 84.61W
08/28/2021  E1.00 INCH       GRATIOT            MI   PUBLIC

            QUARTER SIZE HAIL AT N STATE ROAD AND W
            LINCOLN ROAD.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
702 PM EDT SAT AUG 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0639 PM     TSTM WND GST     4 WNW ITHACA            43.32N 84.68W
08/28/2021  M68 MPH          GRATIOT            MI   AWOS

            AWOS STATION KAMN ALMA.

&&

WDM

Special Weather Statement
National Weather Service Grand Rapids MI
748 PM EDT Sat Aug 28 2021

MIZ058-059-290045-
Clinton MI-Ionia MI-
748 PM EDT Sat Aug 28 2021

...A strong thunderstorm will impact portions of central Ionia and
northwestern Clinton Counties through 845 PM EDT...

At 747 PM EDT, Doppler radar was tracking a strong thunderstorm near
Saranac, or 7 miles southeast of Lowell, moving east at 20 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Ionia...               St. Johns...           Portland...
Saranac...             Fowler...              Westphalia...
Lyons...               Maple Rapids...        Muir...
Pewamo...              Hubbardston...         Clarksville...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

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

&&

LAT...LON 4295 8454 4277 8526 4277 8529 4284 8531
      4295 8531 4312 8476 4312 8465
TIME...MOT...LOC 2347Z 259DEG 16KT 4287 8522

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

JC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
838 PM EDT SAT AUG 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0812 PM     TSTM WND GST     2 SW LYONS              42.96N 84.98W
08/28/2021  E40 MPH          IONIA              MI   PUBLIC

            THUNDERSTORMS WINDS, WITH ESTIMATED GUSTS AS
            HIGH AS 40 MPH CAUSE SOME SMALL BRANCHES AND
            LIMBS TO BE BLOWN DOWN. THERE WAS PEA SIZE
            HAIL WITH THIS STORM TOO.

&&

WDM

Special Weather Statement
National Weather Service Grand Rapids MI
902 PM EDT Sat Aug 28 2021

MIZ059-290200-
Clinton MI-
902 PM EDT Sat Aug 28 2021

...A strong thunderstorm will impact portions of Clinton County
through 1000 PM EDT...

At 902 PM EDT, Doppler radar was tracking a strong thunderstorm near
St. Johns, moving east at 35 mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
St. Johns...           Elsie...               Ovid...
Fowler...              Westphalia...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4285 8482 4306 8481 4312 8437 4286 8437
TIME...MOT...LOC 0102Z 255DEG 31KT 4298 8465

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

JC