An isolated severe storm produced a 69 mph wind gust at Big Sable Point.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS GRR wrote it up.
An isolated severe storm produced a 69 mph wind gust at Big Sable Point.
The local office's own words before the first event, 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 the first event at Aug 27, 6:24 AM EST, 3 hours 46 minutes earlier.
Area Forecast Discussion
National Weather Service Grand Rapids MI
724 AM EDT Thu Aug 27 2020
LATEST UPDATE...
Aviation
.SYNOPSIS...
Issued at 223 AM EDT Thu Aug 27 2020
- Risk for severe weather and flooding into Friday night
- Considerable cool down this weekend
&&
.DISCUSSION...(Today through next Wednesday)
Issued at 223 AM EDT Thu Aug 27 2020
- Risk for severe weather and flooding into Friday night
For much of today the region will be under speed divergence as the
low level jet pulls off to the east. This may limit the
thunderstorm risk. However tonight...especially later at night a
low level jet starts to develop in IA and WI with increasing
convergence here in MI. Instability builds along this developing
baroclinic zone. This will likely yield an expanding area of
showers and thunderstorm. Rainfall will become increasingly
efficient as the PWAT values climb to near 2 inches. Severe
weather risk through tonight may be isolated as the instability
is shown to be limited.
For Friday into Friday night the low level baroclinic zone
remains over the CWA as an upper wave drops in from the northwest.
The dynamic cooling coupled with increasing PWAT will spell
numerous showers and thunderstorms with heavy rain at times. Trop
level divergence peaks in the afternoon and evening as the PV
anomaly shifts eastward just north of the Great Lakes Region. If
the cells can train over the same area...which is a
possibility...an increased risk for flooding could develop.
Instability and deep layer shear build during the day on Friday. A
low level jet is shown to increase as it tracks through during the
late afternoon and evening hours. The CWA is shown to be in the
zone between higher helicity values to the north and stronger
instability to the south. Thus...an increased risk for severe
weather and perhaps tornadoes could develop. Close monitoring will
be needed going forward.
- Considerable cool down this weekend
Northerly winds behind the departing storm advect a cooler airmass
down into the CWA for this weekend. Temps at 925 mb bottom out in
the 11 to 13 deg C range Sunday morning. This is cold enough for
lake effect given water temps up over 20 deg C. We will feature
well below normal temperatures.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 720 AM EDT Thu Aug 27 2020
This morning we will start off with a risk for LLWS for a few
hours...but as the surface winds increase...the potential for LLWS
will diminish. There is also IFR clouds just south of KJXN at this
time. Forecasts suggest these low clouds will stay south of KJXN
as they dissipate through the morning. Thunderstorms could start
to develop mid to late afternoon and into sunset. Another batch of
showers and storms could move in or develop overhead later
tonight. Impacts should be on the increase tonight with MVFR
ceilings arriving late.
&&
.MARINE...
Issued at 223 AM EDT Thu Aug 27 2020
With a westerly low level jet tracking through the region this
morning...gusty winds are expected over the nearshore waters.
Based on the mixing heights...gusts over 20 knots are expected. We
will maintain the small craft advisory and beach hazards.
Another high wind and wave event is looking more likely with time
over the weekend. As a cooler airmass flows down from the north
the lake becomes unstable. The will likely result in efficient
wave building which will lead to hazardous boating and swim
conditions.
&&
.HYDROLOGY...
Issued at 321 PM EDT Wed Aug 26 2020
Several rounds of heavy rain could produce 2-3 inches of rain in
some parts of West Michigan over the next few days. The good news
is that the soils are currently quite dry, so we are not expecting
significant runoff to cause any river flooding issues. However,
with the hot and humid airmass that we have in place, rain during
storms will be very heavy and has the potential to cause localized
flooding and ponding of water in low spots, urban areas, and
other poor drainage spots.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement until 5 PM EDT this afternoon for MIZ037-
043-050-056-064-071.
LM...Small Craft Advisory until 5 PM EDT this afternoon for
LMZ844>849.
&&
SYNOPSIS...MJS
DISCUSSION...MJS
AVIATION...MJS
HYDROLOGY...AMD
MARINE...MJSHazardous Weather Outlook National Weather Service Grand Rapids MI 346 AM EDT Thu Aug 27 2020 MIZ037>040-043>046-050>052-056>059-064>067-071>074-280800- Mason-Lake-Osceola-Clare-Oceana-Newaygo-Mecosta-Isabella-Muskegon- Montcalm-Gratiot-Ottawa-Kent-Ionia-Clinton-Allegan-Barry-Eaton- Ingham-Van Buren-Kalamazoo-Calhoun-Jackson- 346 AM EDT Thu Aug 27 2020 This hazardous weather outlook is for portions of southwest Lower Michigan. .DAY ONE...Today and Tonight Scattered thunderstorms today will be numerous later tonight. A slight risk for severe weather exists with damaging winds and hail the main threats. Locally heavy rain could lead urban and poor drainage flooding. .DAYS TWO THROUGH SEVEN...Friday through Wednesday A slight risk for severe weather and flooding exists for Friday into Friday night. Damaging winds and an isolated tornado are possible. In addition areas of heavy rain could lead to urban and small stream flooding. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed Friday into Friday night. LMZ844>849-280800- 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- 346 AM EDT Thu Aug 27 2020 This hazardous weather outlook is for portions of southwest Lower Michigan. .DAY ONE...Today and Tonight Hazardous swim and boating conditions will exist today. scattered thunderstorms today and tonight could lead to cloud to water lightning strikes and gusty winds. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Thunderstorms Friday into Friday night could produce gusty winds and cloud to water lightning strikes. Winds and waves will be increasing Saturday into Saturday night. As cooler air flows in from the north...conditions are likely to become hazardous for swimmers and small craft. .SPOTTER INFORMATION STATEMENT...
The Green Bay radar (KGRB), 137 km away, was scanning. The volume nearest the first event began at 15:09 UTC.
1 thunderstorm wind. Local standard time, as filed.
A 69 mph wind gust was measured at the Big Sable Point mesonet station in Ludington.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Michigan in 2020Every state in 2020This day in weather historyWarnings in Michigan, August 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 907267.