A thunderstorm moving through Saginaw Bay produced a wind gust near 40 knots.
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The episode as NWS DTX wrote it up.
A thunderstorm moving through Saginaw Bay produced a wind gust near 40 knots.
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 Detroit, MI wrote its last area forecast discussion before the first event at Aug 9, 1:56 PM EST, 1 hour 54 minutes earlier.
Area Forecast Discussion National Weather Service Detroit/Pontiac MI 256 PM EDT Sun Aug 9 2020 .DISCUSSION... A hot and humid afternoon as high temperatures push into the upper 80s/toward 90 degrees with dew pts near 70 degrees. Subsidence/anticyclone bubble seen in 850-700 MB Theta-E fields tracking through southern lower Michigan this evening, and expecting dry conditions, exception perhaps over the Thumb region/near Saginaw Bay where lingering frontal boundary/remnant weak 500 MB speed max and possible marine influenced convergence may be sufficient to tap into MLcapes 1500+ J/kg. Fortunately, 0-6 km bulk shear is low and mid level lapse rates weak. Very warm (10+ C at 700 MB) and dry mid level airmass will continue to spread into lower Michigan tonight, and likely be sufficient to cap/keep dry conditions through the bulk of the night on this side of the state. Although, the increasing low level jet and moisture gradient/upper level PV advection impinging on areas west of U.S. 23 by 12z supports a low/slight chance of activity arriving around sunrise. Seasonably strong cold front to track through Central Great Lakes late tomorrow/tomorrow evening, with good moisture pooling, as PW values ramp up around 2 inches and surface dew pts aoa 70 degrees. Favorable timing of the front to build instability, but lots of convective debris throughout the day to work through, especially if a complex potentially develops upstream over the Western Ohio Valley. Otherwise, instability could become significant (MLcapes 1500-2000 J/kg per Euro/Canadian) over southeast Michigan, with steep mid level lapse rates and increasing 0-6 KM bulk shear supportive of severe storms. Still wide-range of outcomes indicated in the various hi-res convective models, including timing issues and probably the reason SPC left southeast Michigan in just general thunder for now. Will maintain the inherited likely pops from the midnight crew, but bumped up the timing just a bit as the low level Theta-E ridge is progged to track through fairly close to 00z Tuesday, with max 500 MB height falls coming through just after midnight. Pseudo zonal flow setting up over the northern Conus on Tuesday, with westerly confluent flow over lower Michigan allowing high pressure to take hold, which looks to be persisting right through Wednesday. Upper level ridge (587+ DAM at 500 MB) slowly builds over Central Great Lakes Thursday/Friday, but low level easterly flow emitting from the high along the Ontario/Quebec border will keep the warm up subdued over southern Michigan, as 850 MB temps hold in the 17-18 C range, right into the Weekend. Increase in moisture from the south Saturday-Sunday with potential shortwave trough tracking through will bring a chance of showers and thunderstorms. Although, 00z Euro ensemble members are all over the map, leading to low confidence forecast. && .MARINE... Light southwest flow will continue to push a warmer and more humid airmass across the local waters the remainder of today and through Monday. Further upstream across the upper Midwest, a slow moving cold front and attendant upper-level disturbance will slowly push southeastward towards the central Great Lakes Monday bringing an increasing potential for scattered showers and thunderstorms. Coverage of showers and thunderstorms will be greatest Monday night associated with the frontal passage. Ahead of the cold front passage, southwest winds will ramp up, with gusts in nearshore waters approaching 20 knots. Outside of a few lingering showers across western Lake Erie and Lake St. Clair Tuesday, drier weather and lighter winds behind the cold front passage will then prevail for the middle of next week with wind direction variable each day with high pressure building overhead. && .PREV DISCUSSION... Issued at 202 PM EDT Sun Aug 9 2020 AVIATION... Precipitation stayed north and/or east of the terminals today followed by a thickening of the diurnal cumulus field early this afternoon, including some brief MVFR ceilings. Current dryness will persist into the overnight period ahead of a slowly traversing cold front. FROPA timing has shifted later and the previously anticipated warm front appears to washout well southwest of the terminals. This diminishes the potential for overnight activity leaving Monday precipitation largely tied to pre-frontal showers/storms during the afternoon and evening hours. Introduced a PROB30 for MBS to the highlight the higher potential toward the end of the TAF period, but timing remains uncertain. Winds backed southwesterly in time for the 18Z forecast and expect this to continue with slightly higher speeds midday Monday with high-based VFR afternoon cu. For DTW...SCT-BKN 4 kft cumulus ceiling with southwesterly flow continues, unless the Lake Erie breeze front makes far enough inroads to back winds south/southeasterly late this afternoon. Some degree of shower/thunderstorm activity is expected on Monday, mainly beginning late afternoon/evening. Included a PROB30 for SHRA after 21Z. DTW THRESHOLD PROBABILITIES... * High for ceiling at or below 5000 ft today and medium on Monday. * Low for lake-breeze to shift winds from southwest to southeast after 20z this afternoon. * Low for thunderstorms on Monday. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && DISCUSSION...99 MARINE.......IRL AVIATION.....KK You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.
Hazardous Weather Outlook National Weather Service Detroit/Pontiac MI 247 PM EDT Sun Aug 9 2020 MIZ047>049-053>055-062-063-101100- Midland-Bay-Huron-Saginaw-Tuscola-Sanilac-Lapeer-St. Clair- 247 PM EDT Sun Aug 9 2020 This hazardous weather outlook is for portions of southeast Michigan. .DAY ONE...This Afternoon and Tonight An isolated thunderstorm remains possible into the early evening hours. If a storm does go up, it is not expected to be severe, but heavy rainfall and wind gusts around 45 mph would be likely. Storms motion looks to be east around 20 mph. .DAYS TWO THROUGH SEVEN...Monday through Saturday There is a chance of thunderstorms Monday and Monday night. Storms could approach severe strength with damaging wind the primary hazard Monday evening into early Tuesday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today and tonight. LCZ460-LEZ444-LHZ361>363-421-422-441>443-462>464-101100- Lake St Clair- Michigan Waters of Lake Erie from Detroit River to North Cape MI- Lake Huron from 5NM east of Mackinac Bridge to Presque Isle Lt beyond 5 NM off shore- Lake Huron from Presque Isle Light to Sturgeon Point MI beyond 5NM off shore- Lake Huron from Sturgeon Point to Alabaster MI beyond 5NM off shore- Outer Saginaw Bay SW of Alabaster to Port Austin MI to Inner Saginaw Bay-Inner Saginaw Bay SW of Point Au Gres to Bay Port MI- Port Austin to Harbor Beach MI-Harbor Beach to Port Sanilac MI- Port Sanilac to Port Huron MI- Lake Huron from Port Austin to Harbor Beach beyond 5NM Off Shore- Lake Huron from Harbor Beach to Port Sanilac beyond 5NM Off Shore- Lake Huron from Port Sanilac to Port Huron beyond 5NM Off Shore- 247 PM EDT Sun Aug 9 2020 This hazardous weather outlook is for portions of Lake Erie, Lake Huron and Lake St Clair. .DAY ONE...This Afternoon and Tonight Isolated thunderstorms remain possible into the evening hours over southern Lake Huron. heavy rainfall and wind gusts around 40 knots would occur with any thunderstorm. Storm motion looks to be east around 15 knots. .DAYS TWO THROUGH SEVEN...Monday through Saturday Thunderstorms remain in the forecast Monday and Tuesday. Storms could approach severe strength with damaging wind the primary hazard Monday evening into early Tuesday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today and tonight. MIZ060-061-068>070-075-076-082-083-101100- Shiawassee-Genesee-Livingston-Oakland-Macomb-Washtenaw-Wayne-Lenawee- Monroe- 247 PM EDT Sun Aug 9 2020 This hazardous weather outlook is for portions of southeast Michigan. .DAY ONE...This Afternoon and Tonight No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Monday through Saturday There is a chance of thunderstorms Monday and Monday night, with a slight chance during the daytime hours of Tuesday. Storms could approach severe strength with damaging wind the primary hazard Monday evening into early Tuesday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today and tonight. You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit. SF
The NCL Michigan radar (KAPX), 136 km away, was scanning. The volume nearest the first event began at 20:50 UTC.
1 marine thunderstorm wind. Local standard time, as filed.
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Every storm in Lake Huron in 2020Every state in 2020This day in weather history
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: 911857.