Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 72, NWS Detroit, MI

August 11, 2021Livingston County, Michigan

NWS Detroit, MI issued this severe thunderstorm warning at Aug 11, 2021, 2:42 PM EDT for Livingston County, Michigan. It was in force for 63 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
Aug 11, 2021, 2:42 PM EDT (18:42 UTC)
Expired
Aug 11, 2021, 3:45 PM EDT
In force
63 min
Issued by
NWS Detroit, MI
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Livingston County, MI

The radar

The Detroit radar (KDTX), 33 km from the middle of the area, began a volume at 18:42 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 11, 3:08 PM EDTTSTM WND DMGHamburg, MIREPORTS OF MULTIPLE TREES AND POWER LINES DOWN RELAYED VIA SOCIAL MEDIA.
Aug 11, 3:12 PM EDTTSTM WND DMG4 W Brighton, MILARGE TREE DOWN BLOCKING ROAD
Aug 11, 3:12 PM EDTTSTM WND DMG4 W Brighton, MILARGE TREE DOWN BLOCKING ROAD NEAR CHILSON AND COON LAKE RD...CORRECTED TO INCLUDE CROSSROADS
Aug 11, 3:15 PM EDTTSTM WND DMGHartland, MIREPORTS FROM SEVERAL SOURCES OF NUMEROUS TREES DOWN NEAR HARTLAND.

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 11, 2:32 PM EDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 6.7 hours before the alert went out and 37 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 2021-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 106 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 2021-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 169 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
106 J/kg
Mixed-layer CIN
-290 J/kg
Mixed-layer LCL
1220 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
169 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

069 
WUUS53 KDTX 111842
SVRDTX
MIC093-111945-
/O.NEW.KDTX.SV.W.0072.210811T1842Z-210811T1945Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Detroit/Pontiac MI
242 PM EDT Wed Aug 11 2021

The National Weather Service in Detroit/Pontiac has issued a

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

* Until 345 PM EDT.

* At 240 PM EDT, a severe thunderstorm was located over Gregory, or 8
  miles west of Pinckney, moving northeast at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* This severe thunderstorm will be near...
  Pinckney around 250 PM EDT.
  Howell around 300 PM EDT.
  Brighton around 310 PM EDT.
  Hartland around 320 PM EDT.

Other locations impacted by this severe thunderstorm include Parkers
Corners, Lakeland, Plainfield, Island Lake State Recreation Area,
Chilson, Unadilla, Pinckney State Recreation Area, Conway Township,
Hell and Tyrone Township.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4278 8369 4243 8366 4242 8414 4277 8416
TIME...MOT...LOC 1840Z 245DEG 30KT 4248 8411 

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

$$

KDK
2 follow-up statements
421 
WWUS53 KDTX 111900
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
300 PM EDT Wed Aug 11 2021

MIC093-111945-
/O.CON.KDTX.SV.W.0072.000000T0000Z-210811T1945Z/
Livingston MI-
300 PM EDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EDT
FOR LIVINGSTON COUNTY...

At 258 PM EDT, a severe thunderstorm was located near Pinckney,
moving northeast at 50 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

This severe storm will be near...
  Hamburg around 310 PM EDT.
  Brighton around 315 PM EDT.
  Hartland and South Lyon around 320 PM EDT.

Additional storms extended eastward from Pinckney and northwest 
toward Fowlerville.

Other locations impacted by this severe thunderstorm include Parkers
Corners, Lakeland, Plainfield, Island Lake State Recreation Area,
Chilson, Unadilla, Pinckney State Recreation Area, Conway Township,
Hell and Tyrone Township.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4278 8369 4243 8366 4242 8414 4277 8416
TIME...MOT...LOC 1858Z 245DEG 41KT 4248 8401 

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

$$

BT
024 
WWUS53 KDTX 111941
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
341 PM EDT Wed Aug 11 2021

MIC093-111950-
/O.EXP.KDTX.SV.W.0072.000000T0000Z-210811T1945Z/
Livingston MI-
341 PM EDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR LIVINGSTON COUNTY WILL EXPIRE
AT 345 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

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

LAT...LON 4278 8369 4243 8366 4242 8414 4277 8416
TIME...MOT...LOC 1940Z 245DEG 30KT 4262 8359 

$$

BT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 11:43 PM EDTSevere Thunderstorm WarningDTXBay, Midland, Saginaw62 min
Aug 10, 11:53 PM EDTSpecial Weather StatementDTXGenesee, Livingston, Shiawassee, Washtenaw52 min
Aug 10, 11:58 PM EDTSpecial Marine WarningDTX92 min
Aug 11, 12:02 AM EDTSevere Thunderstorm WarningDTXGenesee, Livingston, Oakland, Shiawassee, Washtenaw58 min
Aug 11, 12:43 AM EDTSevere Thunderstorm WarningDTXBay, Huron, Saginaw, Tuscola47 min
Aug 11, 1:09 AM EDTSpecial Marine WarningDTX81 min
Aug 11, 1:11 AM EDTSpecial Weather StatementDTXHuron49 min
Aug 11, 1:29 AM EDTSpecial Marine WarningDTX46 min
Aug 11, 4:04 AM EDTHeat AdvisoryDTXLenawee, Livingston, Macomb, Monroe, Oakland, Washtenaw and 1 more13 hr
Aug 11, 2:22 PM EDTSevere Thunderstorm WarningDTXLenawee, Washtenaw68 min
Aug 11, 2:31 PM EDTSevere Thunderstorm WarningDTXSaginaw42 min
Aug 11, 2:59 PM EDTSevere Thunderstorm WarningDTXMonroe, Wayne76 min
Aug 11, 3:02 PM EDTSpecial Weather StatementDTXGenesee58 min
Aug 11, 3:09 PM EDTSevere Thunderstorm WarningDTXOakland66 min
Aug 11, 3:16 PM EDTSevere Thunderstorm WarningDTXGenesee, Shiawassee59 min
Aug 11, 3:17 PM EDTSpecial Marine WarningDTX88 min
Aug 11, 3:36 PM EDTSpecial Marine WarningDTX84 min
Aug 11, 3:36 PM EDTSevere Thunderstorm WarningDTXLapeer, Macomb, Saint Clair, Sanilac69 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.