Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 31, NWS Gaylord, MI

August 11, 2021Chippewa County, Mackinac County, Michigan

NWS Gaylord, MI issued this severe thunderstorm warning at Aug 11, 2021, 4:11 PM EDT for Chippewa County, Mackinac County, Michigan. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 11, 2021, 4:11 PM EDT (20:11 UTC)
Expired
Aug 11, 2021, 5:00 PM EDT
In force
49 min
Issued by
NWS Gaylord, MI
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Chippewa County, MI, Mackinac County, MI

The radar

The NCL Michigan radar (KAPX), 123 km from the middle of the area, began a volume at 20:11 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.

The nearest sounding before it

Alpena, MI (KAPX), launched 12:00Z, 8.2 hours before the alert went out and 163 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, Alpena, MI at 12:00Z on 2021-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Alpena, MI at 12:00Z on 2021-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 158 square meters per square second.19395878Sfc1 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
2 J/kg
Mixed-layer CIN
-340 J/kg
Mixed-layer LCL
1366 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
158 m²/s²
0-3 km storm-relative helicity
172 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

781 
WUUS53 KAPX 112011
SVRAPX
MIC033-097-112100-
/O.NEW.KAPX.SV.W.0031.210811T2011Z-210811T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Gaylord MI
411 PM EDT Wed Aug 11 2021

The National Weather Service in Gaylord has issued a

* Severe Thunderstorm Warning for...
  Southeastern Chippewa County in eastern Michigan...
  Southeastern Mackinac County in eastern Michigan...

* Until 500 PM EDT.

* At 410 PM EDT, severe thunderstorms were located along a line
  extending from 10 miles southeast of Munuscong to 6 miles south of
  Goetzville to near Mackinac Island, moving southeast at 50 mph.

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

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Saint Marys River and Detour Village around 415 PM EDT.
  Potagannissing Bay around 420 PM EDT.
  Drummond Island around 425 PM EDT.

Other locations in the path of these severe thunderstorms include
False Detour Channel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4589 8353 4588 8358 4594 8413 4588 8445
      4580 8432 4575 8431 4571 8436 4569 8450
      4582 8474 4588 8458 4586 8455 4592 8448
      4600 8413 4623 8410 4606 8395 4606 8390
      4612 8383 4612 8364 4600 8344
TIME...MOT...LOC 2010Z 305DEG 65KT 4616 8401 4599 8409 4580 8461 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$
2 follow-up statements
694 
WWUS53 KAPX 112032
SVSAPX

Severe Weather Statement
National Weather Service Gaylord MI
432 PM EDT Wed Aug 11 2021

MIC033-097-112100-
/O.CON.KAPX.SV.W.0031.000000T0000Z-210811T2100Z/
Chippewa MI-Mackinac MI-
432 PM EDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT
FOR SOUTHEASTERN CHIPPEWA AND SOUTHEASTERN MACKINAC COUNTIES...

At 431 PM EDT, severe thunderstorms were located along a line
extending from near Drummond Island to 14 miles southeast of Saint
Marys River to Nine Mile Point, moving southeast at 45 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
  False Detour Channel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4589 8353 4588 8358 4594 8413 4588 8445
      4580 8432 4575 8431 4571 8436 4569 8450
      4582 8474 4588 8458 4586 8455 4592 8448
      4600 8413 4623 8410 4606 8395 4606 8390
      4612 8383 4612 8364 4600 8344
TIME...MOT...LOC 2031Z 305DEG 65KT 4598 8364 4581 8372 4562 8424 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$
394 
WWUS53 KAPX 112045
SVSAPX

Severe Weather Statement
National Weather Service Gaylord MI
445 PM EDT Wed Aug 11 2021

MIC097-112053-
/O.CAN.KAPX.SV.W.0031.000000T0000Z-210811T2100Z/
Mackinac MI-
445 PM EDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MACKINAC COUNTY
IS CANCELLED...

The storms which prompted the warning have weakened. Therefore, the 
warning has been cancelled.

LAT...LON 4589 8353 4588 8358 4595 8390 4594 8430
      4597 8421 4598 8412 4599 8417 4600 8413
      4623 8410 4606 8395 4606 8390 4612 8383
      4610 8375 4612 8364 4600 8344
TIME...MOT...LOC 2043Z 305DEG 65KT 4586 8341 4569 8349 4551 8401 

$$

MIC033-112100-
/O.CON.KAPX.SV.W.0031.000000T0000Z-210811T2100Z/
Chippewa MI-
445 PM EDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT
FOR SOUTHEASTERN CHIPPEWA COUNTY...

At 443 PM EDT, severe thunderstorms were located along a line
extending from 7 miles southeast of False Detour Channel to 24 miles
southeast of Drummond Island to near Forty Mile Point, moving 
southeast at 45 mph. This storm produced a measured 60 mph wind gust 
on Neebish Island. 

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

SOURCE...Radar indicated.

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

Locations impacted include...
Drummond Island, False Detour Channel, Saint Marys River,
Potagannissing Bay, Detour Village, Goetzville and Raber.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4589 8353 4588 8358 4595 8390 4594 8430
      4597 8421 4598 8412 4599 8417 4600 8413
      4623 8410 4606 8395 4606 8390 4612 8383
      4610 8375 4612 8364 4600 8344
TIME...MOT...LOC 2043Z 305DEG 65KT 4586 8341 4569 8349 4551 8401 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 9:00 PM EDTSpecial Marine WarningAPX2 hr
Aug 10, 9:44 PM EDTSevere Thunderstorm WarningAPXAntrim, Charlevoix46 min
Aug 10, 10:04 PM EDTSevere Thunderstorm WarningAPXBenzie, Grand Traverse, Leelanau, Manistee, Wexford41 min
Aug 10, 10:30 PM EDTSevere Thunderstorm WarningAPXAntrim, Kalkaska30 min
Aug 10, 10:45 PM EDTSevere Thunderstorm Warning Considerable damage threatAPXBenzie, Grand Traverse, Kalkaska, Leelanau, Missaukee, Wexford45 min
Aug 10, 10:52 PM EDTFlash Flood WarningAPXAntrim, Grand Traverse3 hr
Aug 10, 10:58 PM EDTSevere Thunderstorm WarningAPXAntrim, Crawford, Kalkaska, Otsego32 min
Aug 10, 11:24 PM EDTSevere Thunderstorm WarningAPXAntrim, Crawford, Kalkaska, Otsego51 min
Aug 10, 11:28 PM EDTSevere Thunderstorm WarningAPXCrawford, Kalkaska, Missaukee, Roscommon32 min
Aug 11, 12:13 AM EDTFlash Flood WarningAPXLeelanau3 hr
Aug 11, 12:28 AM EDTSevere Thunderstorm WarningAPXAlcona, Arenac, Iosco, Ogemaw, Oscoda47 min
Aug 11, 12:31 AM EDTSevere Thunderstorm WarningAPXAlcona, Alpena, Montmorency, Oscoda, Presque Isle44 min
Aug 11, 12:37 AM EDTSpecial Marine WarningAPX83 min
Aug 11, 1:46 AM EDTAreal Flood WarningAPXAntrim, Grand Traverse3 hr
Aug 11, 4:12 AM EDTSmall Craft AdvisoryAPX16 hr
Aug 11, 2:52 PM EDTSpecial Marine WarningAPX53 min
Aug 11, 2:59 PM EDTSpecial Weather StatementAPXMackinac31 min
Aug 11, 3:11 PM EDTSpecial Marine WarningAPX64 min
Aug 11, 3:18 PM EDTSpecial Weather StatementAPXChippewa42 min
Aug 11, 3:38 PM EDTSpecial Marine WarningAPX52 min
Aug 11, 3:47 PM EDTSevere Thunderstorm WarningAPXChippewa, Mackinac43 min
Aug 11, 3:58 PM EDTSpecial Marine WarningAPX92 min
Aug 11, 4:24 PM EDTSpecial Marine WarningAPX2 hr
Aug 11, 4:54 PM EDTSevere Thunderstorm WarningAPXCheboygan51 min
Aug 11, 5:00 PM EDTSevere Thunderstorm WarningAPXEmmet18 min
Aug 11, 5:24 PM EDTSevere Thunderstorm WarningAPXCharlevoix, Cheboygan, Emmet36 min
Aug 11, 5:28 PM EDTSpecial Marine WarningAPX2 hr
Aug 11, 5:30 PM EDTSevere Thunderstorm WarningAPXAntrim, Benzie, Grand Traverse, Kalkaska, Leelanau45 min
Aug 11, 5:43 PM EDTSevere Thunderstorm WarningAPXCheboygan, Emmet, Presque Isle47 min
Aug 11, 5:52 PM EDTSevere Thunderstorm WarningAPXCheboygan, Presque Isle38 min
Aug 11, 6:00 PM EDTSevere Thunderstorm Warning Destructive damage threatAPXBenzie, Leelanau30 min
Aug 11, 6:09 PM EDTSevere Thunderstorm WarningAPXAntrim, Crawford, Kalkaska, Otsego35 min
Aug 11, 6:24 PM EDTSevere Thunderstorm Warning Considerable damage threatAPXAntrim, Benzie, Grand Traverse, Kalkaska, Leelanau51 min
Aug 11, 6:26 PM EDTSpecial Marine WarningAPX34 min
Aug 11, 6:31 PM EDTSevere Thunderstorm WarningAPXCrawford, Montmorency, Oscoda, Otsego44 min
Aug 11, 6:58 PM EDTSevere Thunderstorm WarningAPXAlcona, Alpena, Presque Isle47 min
Aug 11, 7:26 PM EDTSpecial Marine WarningAPX46 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.