Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 99, NWS Detroit, MI

August 29, 2021Oakland County, Michigan

NWS Detroit, MI issued this severe thunderstorm warning at Aug 29, 2021, 5:56 PM EDT for Oakland County, Michigan. It was in force for 64 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 29, 2021, 5:56 PM EDT (21:56 UTC)
Expired
Aug 29, 2021, 7:00 PM EDT
In force
64 min
Issued by
NWS Detroit, MI
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Oakland County, MI

The radar

The Detroit radar (KDTX), 6 km from the middle of the area, began a volume at 21:55 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Aug 29, 6:36 PM EDTTSTM WND DMG4 Nne Milford, MISEVERAL TREES REPORTED DOWN ACROSS MILFORD AND HIGHLAND TWP VIA CENTRAL DISPATCH.
Aug 29, 6:47 PM EDTTSTM WND DMGWalled Lake, MITREE DAMAGE REPORTED VIA CENTRAL DISPATCH.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 29, 1:46 PM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 9.9 hours before the alert went out and 8 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Detroit, MI at 12:00Z on 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1500 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Detroit, MI at 12:00Z on 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -80 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1500 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
915 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-80 m²/s²
0-3 km storm-relative helicity
-70 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

776 
WUUS53 KDTX 292156
SVRDTX
MIC125-292300-
/O.NEW.KDTX.SV.W.0099.210829T2156Z-210829T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Detroit/Pontiac MI
556 PM EDT Sun Aug 29 2021

The National Weather Service in Detroit/Pontiac has issued a

* Severe Thunderstorm Warning for...
  Oakland County in southeastern Michigan...

* Until 700 PM EDT.

* At 556 PM EDT, severe thunderstorms were located along a line
  extending from Lake Fenton to near Hartland to near Pinckney,
  moving east at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Severe thunderstorms will be near...
  Holly around 600 PM EDT.
  Milford and Ortonville around 615 PM EDT.
  Oxford around 630 PM EDT.
  Clarkston around 635 PM EDT.
  Pontiac and Novi around 645 PM EDT.
  West Bloomfield around 650 PM EDT.
  Troy around 655 PM EDT.
  Southfield, Royal Oak, Birmingham and Rochester around 700 PM EDT.

Other locations impacted by these severe thunderstorms include
Franklin, Keego Harbor, Waterford, Orchard Lake, Holly State
Recreation Area, Commerce, Rose Center, Lathrup Village, Auburn Hills
and Bingham Farms.

People attending Meadow Brook Amphitheatre should seek safe shelter
immediately!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4249 8367 4287 8369 4289 8310 4249 8309
TIME...MOT...LOC 2156Z 265DEG 31KT 4285 8369 4267 8384 4248 8398 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Mann
4 follow-up statements
164 
WWUS53 KDTX 292208
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
608 PM EDT Sun Aug 29 2021

MIC125-292300-
/O.CON.KDTX.SV.W.0099.000000T0000Z-210829T2300Z/
Oakland MI-
608 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR OAKLAND COUNTY...

At 608 PM EDT, severe thunderstorms were located along a line
extending from near Holly to near Hartland to near Hamburg, moving
east at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Milford and Holly around 615 PM EDT.
  Ortonville around 620 PM EDT.
  Oxford and Clarkston around 635 PM EDT.
  Pontiac and Novi around 645 PM EDT.
  West Bloomfield around 650 PM EDT.
  Rochester around 700 PM EDT.
  Southfield and Birmingham around 705 PM EDT.
  Troy and Royal Oak around 710 PM EDT.

Other locations impacted by these severe thunderstorms include
Franklin, Keego Harbor, Waterford, Orchard Lake, Holly State
Recreation Area, Commerce, Rose Center, Lathrup Village, Auburn Hills
and Bingham Farms.

People attending Meadow Brook Amphitheatre should seek safe shelter
immediately!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4249 8367 4287 8369 4289 8310 4249 8309
TIME...MOT...LOC 2208Z 265DEG 31KT 4286 8357 4268 8372 4249 8386 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke
850 
WWUS53 KDTX 292224
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
624 PM EDT Sun Aug 29 2021

MIC125-292300-
/O.CON.KDTX.SV.W.0099.000000T0000Z-210829T2300Z/
Oakland MI-
624 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR OAKLAND COUNTY...

At 624 PM EDT, severe thunderstorms were located along a line
extending from near Ortonville to near Clarkston to near South Lyon,
moving east at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Oxford and Clarkston around 630 PM EDT.
  Pontiac around 645 PM EDT.
  West Bloomfield around 650 PM EDT.
  Southfield, Birmingham and Rochester around 700 PM EDT.
  Royal Oak around 705 PM EDT.
  Troy around 710 PM EDT.

Other locations impacted by these severe thunderstorms include
Franklin, Keego Harbor, Waterford, Orchard Lake, Holly State
Recreation Area, Commerce, Rose Center, Lathrup Village, Auburn Hills
and Bingham Farms.

People attending Meadow Brook Amphitheatre should seek safe shelter
immediately!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4249 8367 4287 8369 4289 8310 4249 8309
TIME...MOT...LOC 2224Z 256DEG 31KT 4287 8336 4269 8351 4250 8365 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke
451 
WWUS53 KDTX 292238
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
638 PM EDT Sun Aug 29 2021

MIC125-292300-
/O.CON.KDTX.SV.W.0099.000000T0000Z-210829T2300Z/
Oakland MI-
638 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR OAKLAND COUNTY...

At 638 PM EDT, severe thunderstorms were located along a line
extending from near Dryden to near Pontiac to near Novi, moving east
at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Rochester around 655 PM EDT.
  Southfield and Birmingham around 700 PM EDT.
  Royal Oak around 705 PM EDT.
  Troy around 710 PM EDT.

Other locations impacted by these severe thunderstorms include
Franklin, Keego Harbor, Waterford, Orchard Lake, Commerce, Lathrup
Village, Auburn Hills, Bingham Farms, Lake Angelus and White Lake.

People attending Meadow Brook Amphitheatre should seek safe shelter
immediately!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4249 8367 4288 8351 4289 8310 4249 8309
TIME...MOT...LOC 2238Z 256DEG 31KT 4287 8316 4269 8331 4250 8345 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke
874 
WWUS53 KDTX 292300
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
700 PM EDT Sun Aug 29 2021

MIC125-292310-
/O.EXP.KDTX.SV.W.0099.000000T0000Z-210829T2300Z/
Oakland MI-
700 PM EDT Sun Aug 29 2021

...THE SEVERE THUNDERSTORM WARNING FOR OAKLAND COUNTY HAS EXPIRED...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning has been allowed to expire.  However gusty
winds are still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
southeastern Michigan.

LAT...LON 4249 8367 4288 8351 4289 8310 4249 8309
TIME...MOT...LOC 2300Z 265DEG 31KT 4288 8292 4271 8307 4252 8321 

$$

Behnke

The office that day

Everything else NWS Detroit, MI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 28, 8:18 PM EDTSpecial Weather StatementDTXSaginaw72 min
Aug 28, 8:22 PM EDTSpecial Weather StatementDTXSaint Clair, Sanilac68 min
Aug 28, 10:00 PM EDTSevere Thunderstorm WarningDTXShiawassee20 min
Aug 28, 10:17 PM EDTSpecial Weather StatementDTXGenesee28 min
Aug 29, 1:53 AM EDTSpecial Weather StatementDTXBay, Midland67 min
Aug 29, 2:16 AM EDTSevere Thunderstorm WarningDTXBay, Midland44 min
Aug 29, 2:32 AM EDTSpecial Marine WarningDTX42 min
Aug 29, 3:40 PM EDTSpecial Weather StatementDTXBay, Midland65 min
Aug 29, 3:54 PM EDTSpecial Marine WarningDTX108 min
Aug 29, 4:07 PM EDTSpecial Weather StatementDTXSaginaw, Shiawassee83 min
Aug 29, 4:30 PM EDTSevere Thunderstorm WarningDTXSaginaw, Shiawassee75 min
Aug 29, 4:38 PM EDTSpecial Weather StatementDTXHuron67 min
Aug 29, 4:58 PM EDTSevere Thunderstorm WarningDTXHuron62 min
Aug 29, 5:11 PM EDTSevere Thunderstorm WarningDTXBay, Genesee, Tuscola79 min
Aug 29, 5:25 PM EDTSevere Thunderstorm WarningDTXLivingston65 min
Aug 29, 5:32 PM EDTSpecial Marine WarningDTX118 min
Aug 29, 5:58 PM EDTSevere Thunderstorm WarningDTXLapeer62 min
Aug 29, 6:00 PM EDTSevere Thunderstorm WarningDTXHuron59 min
Aug 29, 6:13 PM EDTSevere Thunderstorm WarningDTXSanilac77 min
Aug 29, 6:37 PM EDTSevere Thunderstorm WarningDTXMacomb, Saint Clair83 min
Aug 29, 6:45 PM EDTSevere Thunderstorm WarningDTXLenawee75 min
Aug 29, 6:51 PM EDTSpecial Marine WarningDTX114 min
Aug 29, 7:00 PM EDTSevere Thunderstorm WarningDTXWashtenaw57 min
Aug 29, 7:23 PM EDTSpecial Weather StatementDTXMonroe67 min
Aug 29, 7:29 PM EDTSpecial Weather StatementDTXWayne61 min
Aug 29, 7:30 PM EDTSpecial Marine WarningDTX68 min

Nearby

Severe Thunderstorm Warnings in Michigan, 2021Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.