Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 21, NWS Detroit, MI

June 29, 20214 counties in Michigan

NWS Detroit, MI issued this severe thunderstorm warning at Jun 29, 2021, 1:06 PM EDT for 4 counties in Michigan. It was in force for 54 min. 4 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
Jun 29, 2021, 1:06 PM EDT (17:06 UTC)
Expired
Jun 29, 2021, 2:00 PM EDT
In force
54 min
Issued by
NWS Detroit, MI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Genesee County, MI, Livingston County, MI, Oakland County, MI, Shiawassee County, MI

The radar

The Detroit radar (KDTX), 47 km from the middle of the area, began a volume at 17:06 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
Jun 29, 1:19 PM EDTTSTM WND DMGByron, MISPOTTERS AND COUNTY OFFICIALS REPORTED NUMEROUS TREES DOWN ACROSS FAR SOUTHERN SHIAWASEE COUNTY.
Jun 29, 1:36 PM EDTTSTM WND DMGGrand Blanc, MIREPORTS OF NUMEROUS TREES DOWN ACROSS GRAND BLANC.
Jun 29, 1:48 PM EDTTSTM WND DMG4 S Grand Blanc, MIMEDIA RECEIVED MULTIPLE REPORTS OF TREES DOWN IN GRAND BLANC AREA
Jun 29, 1:50 PM EDTTSTM WND DMGAtlas, MIA SPOTTER REPORTED A LARGE TREE AND SEVERAL LARGE TREE LIMBS BLOWN DOWN. A SHED WAS ALSO DAMAGED AND HAD ITS ROOF BLOWN OFF.

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

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 5.1 hours before the alert went out and 50 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 2021-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 681 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 2021-06-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 108 square meters per square second.193958Sfc1 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
681 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
1064 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
108 m²/s²
0-3 km storm-relative helicity
105 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.3

Open this sounding in Storm Lab

The text

As transmitted.

358 
WUUS53 KDTX 291706
SVRDTX
MIC049-093-125-155-291800-
/O.NEW.KDTX.SV.W.0021.210629T1706Z-210629T1800Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Detroit/Pontiac MI
106 PM EDT Tue Jun 29 2021

The National Weather Service in Detroit/Pontiac has issued a

* Severe Thunderstorm Warning for...
  Northwestern Oakland County in southeastern Michigan...
  Southern Shiawassee County in southeastern Michigan...
  Northern Livingston County in southeastern Michigan...
  Southern Genesee County in southeastern Michigan...

* Until 200 PM EDT.

* At 104 PM EDT, a severe thunderstorm was located near Perry, moving
  east at 40 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Fowlerville around 110 PM EDT.
  Bancroft around 115 PM EDT.
  Cohoctah and Oak Grove around 120 PM EDT.

Other locations in the path of this severe thunderstorm include
Byron, Gaines, Linden, Fenton, Lake Fenton and Holly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Damaging winds and continuous cloud to ground lightning is occurring 
with this storm. Move indoors immediately. Lightning is one of nature's 
leading killers. Remember, if you can hear thunder, you are close enough to 
be struck by lightning.

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

&&

LAT...LON 4288 8435 4303 8347 4267 8346 4262 8414
      4277 8416 4278 8432
TIME...MOT...LOC 1704Z 262DEG 33KT 4275 8416 

HAIL...1.00IN
WIND...60MPH
 
$$

AA
2 follow-up statements
178 
WWUS53 KDTX 291720
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
120 PM EDT Tue Jun 29 2021

MIC049-093-125-155-291800-
/O.CON.KDTX.SV.W.0021.000000T0000Z-210629T1800Z/
Oakland MI-Shiawassee MI-Livingston MI-Genesee MI-
120 PM EDT Tue Jun 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM EDT
FOR NORTHWESTERN OAKLAND...SOUTHEASTERN SHIAWASSEE...NORTHERN
LIVINGSTON AND SOUTHERN GENESEE COUNTIES...

At 119 PM EDT, a severe thunderstorm was located over Byron, or 8
miles southeast of Durand, moving east at 45 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

This severe storm will be near...
  Linden around 125 PM EDT.

Other locations in the path of this severe thunderstorm include
Fenton, Holly, Lake Fenton, Grand Blanc and Goodrich.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 4288 8409 4301 8347 4293 8347 4272 8346
      4270 8405
TIME...MOT...LOC 1719Z 255DEG 43KT 4282 8390 

HAIL...1.00IN
WIND...60MPH
 
$$

AA
369 
WWUS53 KDTX 291736
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
136 PM EDT Tue Jun 29 2021

MIC155-291745-
/O.CAN.KDTX.SV.W.0021.000000T0000Z-210629T1800Z/
Shiawassee MI-
136 PM EDT Tue Jun 29 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SHIAWASSEE COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has
moved out of the warned area. Therefore, the warning has been
cancelled.

LAT...LON 4301 8347 4293 8347 4272 8346 4271 8378
      4293 8387
TIME...MOT...LOC 1735Z 259DEG 33KT 4286 8370 

$$

MIC049-093-125-291800-
/O.CON.KDTX.SV.W.0021.000000T0000Z-210629T1800Z/
Oakland MI-Livingston MI-Genesee MI-
136 PM EDT Tue Jun 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM EDT
FOR NORTHWESTERN OAKLAND...NORTHEASTERN LIVINGSTON AND SOUTHERN
GENESEE COUNTIES...

At 135 PM EDT, a severe thunderstorm was located over Lake Fenton, or
near Fenton, moving east at 40 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

This severe storm will be near...
  Holly around 140 PM EDT.
  Grand Blanc around 145 PM EDT.
  Goodrich around 150 PM EDT.

Other locations impacted by this severe thunderstorm include Atlas,
Davisburg, Rankin, Holly State Recreation Area, Rose Center, Tyrone
Township and Argentine.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 4301 8347 4293 8347 4272 8346 4271 8378
      4293 8387
TIME...MOT...LOC 1735Z 259DEG 33KT 4286 8370 

HAIL...1.00IN
WIND...60MPH
 
$$

AA

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 28, 8:10 PM EDTSpecial Weather StatementDTXWashtenaw50 min
Jun 28, 8:15 PM EDTSpecial Weather StatementDTXWayne60 min
Jun 28, 8:51 PM EDTSpecial Weather StatementDTXWashtenaw39 min
Jun 28, 9:09 PM EDTSpecial Weather StatementDTXMacomb, Saint Clair66 min
Jun 29, 4:24 AM EDTSpecial Weather StatementDTXLivingston, Oakland66 min
Jun 29, 12:48 PM EDTSpecial Weather StatementDTXLivingston, Shiawassee, Washtenaw57 min
Jun 29, 1:38 PM EDTSpecial Weather StatementDTXLivingston, Washtenaw97 min
Jun 29, 1:55 PM EDTSevere Thunderstorm WarningDTXGenesee, Lapeer, Oakland38 min
Jun 29, 2:02 PM EDTSevere Thunderstorm WarningDTXWashtenaw58 min
Jun 29, 2:30 PM EDTSpecial Weather StatementDTXMacomb, Monroe, Oakland, Saint Clair, Wayne60 min
Jun 29, 2:56 PM EDTSpecial Marine WarningDTX70 min
Jun 29, 3:04 PM EDTSpecial Marine WarningDTX56 min
Jun 29, 3:09 PM EDTAreal Flood AdvisoryDTXMacomb, Oakland, Wayne90 min
Jun 29, 3:09 PM EDTSevere Thunderstorm WarningDTXMacomb, Wayne23 min
Jun 29, 3:28 PM EDTAreal Flood AdvisoryDTXSaint Clair73 min
Jun 29, 5:58 PM EDTSpecial Marine WarningDTX77 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.