Alert archive / Michigan / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 51, NWS Grand Rapids, MI

July 19, 2020Mason County, Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Jul 19, 2020, 7:07 AM EDT for Mason County, Michigan. It was in force for 39 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 19, 2020, 7:07 AM EDT (11:07 UTC)
Expired
Jul 19, 2020, 7:46 AM EDT
In force
39 min
Issued by
NWS Grand Rapids, MI
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Mason County, MI

The radar

The Grand Rapids radar (KGRR), 138 km from the middle of the area, began a volume at 11:11 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

Green Bay/Straub, WI (KGRB), launched 00:00Z, 11.1 hours before the alert went out and 146 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 00:00Z on 2020-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 293 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 00:00Z on 2020-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 122 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
293 J/kg
Mixed-layer CIN
-321 J/kg
Mixed-layer LCL
1478 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
122 m²/s²
0-3 km storm-relative helicity
312 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Grand Rapids, MI wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 19, 6:38 AM EDT, 29 minutes earlier.

Area forecast discussion, Jul 19, 6:38 AM EDT, 29 minutes before
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Hazardous weather outlook, Jul 19, 3:44 AM EDT, 3 hours 23 minutes before
Hazardous Weather Outlook
National Weather Service Grand Rapids MI
344 AM EDT Sun Jul 19 2020

MIZ037>040-043>046-050>052-056>059-064>067-071>074-200745-
Mason-Lake-Osceola-Clare-Oceana-Newaygo-Mecosta-Isabella-Muskegon-
Montcalm-Gratiot-Ottawa-Kent-Ionia-Clinton-Allegan-Barry-Eaton-
Ingham-Van Buren-Kalamazoo-Calhoun-Jackson-
344 AM EDT Sun Jul 19 2020

This hazardous weather outlook is for portions of southwest Lower
Michigan.

.DAY ONE...Today and Tonight

Scattered thunderstorms are expected this morning, mostly near and
north of I-96. It would not be out of the question to see an
isolated damaging wind gust from any storm that does develop this
morning. Locally heavy rain would be a more significant threat
but even that would be isolated.

Later this morning into mid afternoon thunderstorms should
redevelop, mostly near and south of I-96 and those storms may have
damaging winds and locally heavy rainfall associated with them.
The greatest risk for that would be in the I-69 area.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

A frontal wave moving through the area between Tuesday and
Wednesday is expected to bring thunderstorms back to the area.
Some locally heavy rainfall is possible from those storms.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not out the question today.

LMZ844>849-200745-
St Joseph to South Haven MI-South Haven to Holland MI-
Holland to Grand Haven MI-Grand Haven to Whitehall MI-
Whitehall to Pentwater MI-Pentwater to Manistee MI-
344 AM EDT Sun Jul 19 2020

This hazardous weather outlook is for portions of southwest Lower
Michigan.

.DAY ONE...Today and Tonight

The wind and waves will be hazardous to both small craft and
swimmers into this evening. Scattered thunderstorms are possible
until midday.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Thunderstorms are possible from Tuesday into Wednesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not out of the question today.

wdm

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 6:42 AM EDTSpecial Marine WarningGRR19 min
Jul 19, 6:52 AM EDTSpecial Marine WarningGRR45 min
Jul 19, 6:56 AM EDTSpecial Marine WarningGRR64 min
Jul 19, 7:49 AM EDTSpecial Marine WarningGRR61 min
Jul 19, 8:25 AM EDTSevere Thunderstorm WarningGRRIsabella, Mecosta44 min
Jul 19, 8:54 AM EDTSevere Thunderstorm WarningGRRGratiot51 min
Jul 19, 11:44 AM EDTSevere Thunderstorm WarningGRRCalhoun20 min
Jul 19, 12:03 PM EDTSpecial Weather StatementGRRAllegan, Barry, Calhoun, Eaton, Ingham, Jackson and 2 more57 min
Jul 19, 12:58 PM EDTSpecial Marine WarningGRR62 min
Jul 19, 1:34 PM EDTSevere Thunderstorm WarningGRRVan Buren40 min

Nearby

Severe Thunderstorm Warnings in Michigan, 2020Every severe thunderstorm warning in 2020

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.