Alert archive / Michigan / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 85, NWS Grand Rapids, MI

September 7, 2021Kent County, Ottawa County, Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Sep 7, 2021, 2:40 PM EDT for Kent County, Ottawa County, Michigan. It was in force for 39 min. 3 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, 2:40 PM EDT (18:40 UTC)
Expired
Sep 7, 2021, 3:19 PM EDT
In force
39 min
Issued by
NWS Grand Rapids, MI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Kent County, MI, Ottawa County, MI

The radar

The Grand Rapids radar (KGRR), 34 km from the middle of the area, began a volume at 18:45 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, 3:00 PM EDTTSTM WND DMG5 Se Sand Lake, MIPHOTO OF 30-INCH-DIAMETER FALLEN TREE AT THE NELSON CEMETERY...VIA SOCIAL MEDIA. TIME ESTIMATED FROM RADAR.
Sep 7, 3:00 PM EDTTSTM WND DMG5 Sw Trufant, MIPHOTO OF 26-INCH-DIAMETER TREE ACROSS ROAD...RELAYED VIA SOCIAL MEDIA. TIME ESTIMATED FROM RADAR.
Sep 7, 3:00 PM EDTTSTM WND GST 422 Nw Sparta, MIMESONET STATION MISPN 2.0 NW SPARTA (MAWN).

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

Detroit, MI (KDTX), launched 12:00Z, 6.7 hours before the alert went out and 194 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 2021-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Detroit, MI at 12:00Z on 2021-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1621 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

537 
WUUS53 KGRR 071840
SVRGRR
MIC081-139-071930-
/O.NEW.KGRR.SV.W.0085.210907T1840Z-210907T1930Z/

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

The National Weather Service in Grand Rapids has issued a

* Severe Thunderstorm Warning for...
  Northern Kent County in southwestern Michigan...
  Northeastern Ottawa County in southwestern Michigan...

* Until 330 PM EDT.

* At 240 PM EDT, a severe thunderstorm was located 6 miles northwest
  of Sparta, or 13 miles south of Newaygo, 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...
  Rockford...            Coopersville...        Sparta...
  Grattan...             Cedar Springs...       Conklin...
  Wright...              Kent City...           Sand Lake...
  Casnovia...            Crockery Lake...       Belmont...
  Cannonsburg...         Comstock Park...       Northview...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4312 8597 4312 8591 4320 8591 4321 8579
      4329 8579 4329 8531 4327 8531 4305 8532
      4305 8598
TIME...MOT...LOC 1840Z 272DEG 49KT 4322 8580 

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

$$

HOVING
1 follow-up statement
659 
WWUS53 KGRR 071919
SVSGRR

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

MIC081-139-071928-
/O.CAN.KGRR.SV.W.0085.000000T0000Z-210907T1930Z/
Kent MI-Ottawa MI-
319 PM EDT Tue Sep 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN KENT AND NORTHEASTERN
OTTAWA COUNTIES IS CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.

A Severe Thunderstorm Watch remains in effect until 700 PM EDT for
central, southwestern and west central Michigan.

LAT...LON 4312 8597 4312 8591 4320 8591 4321 8579
      4329 8579 4329 8531 4327 8531 4305 8532
      4305 8598
TIME...MOT...LOC 1915Z 272DEG 49KT 4320 8508 

$$

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, 12:25 PM EDTSevere Thunderstorm WarningGRRMason65 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, 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.