Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 77, NWS Grand Rapids, MI

September 7, 2021Mason County, Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Sep 7, 2021, 12:25 PM EDT for Mason County, Michigan. It was in force for 65 min. 6 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
Sep 7, 2021, 12:25 PM EDT (16:25 UTC)
Expired
Sep 7, 2021, 1:30 PM EDT
In force
65 min
Issued by
NWS Grand Rapids, MI
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

County Mason County, MI

The radar

The Grand Rapids radar (KGRR), 143 km from the middle of the area, began a volume at 16:26 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
Sep 7, 12:58 PM EDTHAIL 1Ludington, MIPHOTO OF QUARTER-SIZED HAIL IN LUDINGTON, DURATION OF 5 MINS...VIA SOCIAL MEDIA. TIME ESTIMATED FROM RADAR.
Sep 7, 12:58 PM EDTHAIL 1.25Ludington, MITIME ESTIMATED FROM RADAR.
Sep 7, 1:00 PM EDTHAIL 25 Se Ludington, MI
Sep 7, 1:11 PM EDTHAIL 1.252 Se Scottville, MI
Sep 7, 1:14 PM EDTHAIL 1Custer, MI
Sep 7, 1:20 PM EDTHAIL 2.57 N Colfax, MIPHOTO OF 2.5-INCH HAIL...VIA SOCIAL MEDIA.

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
Sep 7, 12:21 PM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 4.4 hours before the alert went out and 149 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, Green Bay/Straub, WI at 12:00Z on 2021-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 14 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, Green Bay/Straub, WI at 12:00Z on 2021-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -120 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
14 J/kg
Mixed-layer CIN
-216 J/kg
Mixed-layer LCL
1012 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
-120 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1

Open this sounding in Storm Lab

The text

As transmitted.

228 
WUUS53 KGRR 071625
SVRGRR
MIC105-071730-
/O.NEW.KGRR.SV.W.0077.210907T1625Z-210907T1730Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Rapids MI
1225 PM EDT Tue Sep 7 2021

The National Weather Service in Grand Rapids has issued a

* Severe Thunderstorm Warning for...
  Mason County in west central Michigan...

* Until 130 PM EDT.

* At 1225 PM EDT, a severe thunderstorm was located 7 miles west of
  Ludington SP, moving east at 55 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.

* Locations impacted include...
  Ludington...           Ludington SP...        Scottville...
  Fountain...            Free Soil...           Hamlin Lake...
  Custer...              Walhalla...            

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4417 8604 4382 8604 4382 8643 4396 8646
      4403 8651 4406 8651 4408 8650 4412 8643
      4418 8639
TIME...MOT...LOC 1625Z 266DEG 46KT 4403 8664 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

HOVING
1 follow-up statement
637 
WWUS53 KGRR 071656
SVSGRR

Severe Weather Statement
National Weather Service Grand Rapids MI
1256 PM EDT Tue Sep 7 2021

MIC105-071730-
/O.CON.KGRR.SV.W.0077.000000T0000Z-210907T1730Z/
Mason MI-
1256 PM EDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 PM EDT
FOR MASON COUNTY...

At 1254 PM EDT, severe thunderstorms were located along a line
extending from 5 miles southwest of Ludington SP to near Ludington to
6 miles northwest of Silver Lake SP, moving east at 50 mph.

Another line of severe storms are also near Freesoil.

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.

Locations impacted include...
Ludington...           Ludington SP...        Scottville...
Fountain...            Free Soil...           Hamlin Lake...
Custer...              Walhalla...            

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.

&&

LAT...LON 4417 8604 4382 8604 4382 8643 4396 8646
      4403 8651 4406 8651 4408 8650 4412 8643
      4418 8639
TIME...MOT...LOC 1654Z 267DEG 44KT 4399 8658 4389 8648 4376 8659 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

NJJ

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 7, 11:50 AM EDTSpecial Marine WarningGRR91 min
Sep 7, 12:32 PM EDTSevere Thunderstorm WarningGRRLake, Osceola58 min
Sep 7, 12:40 PM EDTSpecial Marine WarningGRR87 min
Sep 7, 12:54 PM EDTSevere Thunderstorm WarningGRROceana66 min
Sep 7, 1:08 PM EDTTornado WarningGRRClare, Osceola40 min
Sep 7, 1:13 PM EDTSevere Thunderstorm WarningGRRLake, Newaygo37 min
Sep 7, 1:30 PM EDTSpecial Marine WarningGRR60 min
Sep 7, 1:39 PM EDTSevere Thunderstorm Warning Destructive damage threatGRROsceola38 min
Sep 7, 1:51 PM EDTSevere Thunderstorm WarningGRRMuskegon, Oceana54 min
Sep 7, 2:01 PM EDTLakeshore Flood AdvisoryGRRMuskegon4 hr
Sep 7, 2:03 PM EDTSevere Thunderstorm WarningGRRClare46 min
Sep 7, 2:13 PM EDTTornado WarningGRRClare30 min
Sep 7, 2:20 PM EDTSevere Thunderstorm WarningGRRIsabella, Mecosta, Newaygo55 min
Sep 7, 2:23 PM EDTTornado WarningGRRIsabella21 min
Sep 7, 2:40 PM EDTSevere Thunderstorm WarningGRRKent, Ottawa39 min
Sep 7, 3:04 PM EDTSevere Thunderstorm WarningGRRMontcalm56 min
Sep 7, 3:26 PM EDTSevere Thunderstorm WarningGRRClinton, Gratiot, Ionia64 min
Sep 7, 3:37 PM EDTSpecial Marine WarningGRR83 min
Sep 7, 4:05 PM EDTSevere Thunderstorm WarningGRRVan Buren55 min
Sep 7, 4:49 PM EDTSevere Thunderstorm WarningGRRAllegan, Barry, Kalamazoo42 min
Sep 7, 5:13 PM EDTSevere Thunderstorm WarningGRRBarry, Calhoun, Eaton47 min
Sep 7, 5:40 PM EDTSevere Thunderstorm WarningGRRIngham, Jackson50 min
Sep 7, 6:01 PM EDTSevere Thunderstorm WarningGRRClinton29 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.