Alert archive / Michigan / Severe Thunderstorm Watches in 2018

Severe Thunderstorm Watch 254

July 1, 201828 counties in Michigan

The Storm Prediction Center issued this severe thunderstorm watch at Jul 1, 2018, 6:35 PM EDT for 28 counties in Michigan. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jul 1, 2018, 6:35 PM EDT (22:35 UTC)
Expired
Jul 1, 2018, 10:00 PM EDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 28 counties

Allegan County, MI, Antrim County, MI, Barry County, MI, Benzie County, MI, Charlevoix County, MI, Cheboygan County, MI, Chippewa County, MI, Crawford County, MI, Emmet County, MI, Grand Traverse County, MI, Ionia County, MI, Kalkaska County, MI, Kent County, MI, Lake County, MI, Leelanau County, MI, Mackinac County, MI, Manistee County, MI, Mason County, MI, Mecosta County, MI, Missaukee County, MI, Montcalm County, MI, Muskegon County, MI, Newaygo County, MI, Oceana County, MI, Osceola County, MI, Otsego County, MI, Ottawa County, MI, Wexford County, MI

The radar

The NCL Michigan radar (KAPX), 51 km from the middle of the area, began a volume at 22:38 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
5%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jul 1, 6:49 PM EDTSevere Thunderstorm WarningGRRMason, Oceana56 min
Jul 1, 7:10 PM EDTSevere Thunderstorm WarningAPXBenzie, Grand Traverse, Leelanau, Manistee, Wexford50 min
Jul 1, 7:37 PM EDTSevere Thunderstorm WarningAPXAntrim, Charlevoix, Grand Traverse, Kalkaska53 min
Jul 1, 7:47 PM EDTSevere Thunderstorm WarningGRRLake, Newaygo43 min
Jul 1, 7:51 PM EDTSevere Thunderstorm WarningGRRAllegan, Barry, Kent, Ottawa39 min
Jul 1, 7:55 PM EDTSevere Thunderstorm WarningAPXGrand Traverse, Manistee, Wexford50 min
Jul 1, 8:15 PM EDTSevere Thunderstorm WarningGRROsceola45 min
Jul 1, 8:19 PM EDTSevere Thunderstorm WarningAPXKalkaska, Missaukee56 min
Jul 1, 8:22 PM EDTSevere Thunderstorm WarningGRRKent38 min
Jul 1, 8:36 PM EDTSevere Thunderstorm WarningGRRMecosta, Montcalm, Newaygo39 min
Jul 1, 9:03 PM EDTSevere Thunderstorm WarningAPXAntrim, Crawford, Kalkaska, Otsego57 min
Jul 1, 9:05 PM EDTSevere Thunderstorm WarningGRRIsabella, Mecosta40 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 10.6 hours before the alert went out and 222 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 2018-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 10 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 2018-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 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
10 J/kg
Mixed-layer CIN
-259 J/kg
Mixed-layer LCL
1272 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
152 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 30, 9:05 PM EDTMesoscale DiscussionSPCAlger, Delta, Dickinson, Gogebic, Iron, Menominee85 min
Jul 1, 12:37 PM EDTMesoscale DiscussionSPCDelta, Dickinson, Iron, Menominee83 min
Jul 1, 1:04 PM EDTTornado WatchSPCAlger, Delta, Dickinson, Iron, Luce, Marquette and 2 more6 hr
Jul 1, 2:37 PM EDTMesoscale DiscussionSPCAlger, Baraga, Delta, Dickinson, Iron, Luce and 3 more53 min
Jul 1, 4:18 PM EDTMesoscale DiscussionSPCDelta, Luce, Mackinac, Menominee, Schoolcraft87 min
Jul 1, 6:05 PM EDTMesoscale DiscussionSPCAntrim, Benzie, Charlevoix, Cheboygan, Chippewa, Clare and 16 more2 hr
Jul 1, 7:51 PM EDTMesoscale DiscussionSPCAllegan, Berrien, Cass, Van Buren114 min

Nearby

Severe Thunderstorm Watches in Michigan, 2018Every severe thunderstorm watch in 2018

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.