Alert archive / Michigan / Severe Thunderstorm Watches in 2016

Severe Thunderstorm Watch 405

July 21, 201649 counties in Michigan; 11 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jul 21, 2016, 9:45 AM EDT for 49 counties in Michigan; 11 counties in Wisconsin. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Jul 21, 2016, 9:45 AM EDT (13:45 UTC)
Expired
Jul 21, 2016, 4:40 PM EDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 60 counties

Alcona County, MI, Alpena County, MI, Antrim County, MI, Arenac County, MI, Bay County, MI, Benzie County, MI, Charlevoix County, MI, Cheboygan County, MI, Chippewa County, MI, Clare County, MI, Clinton County, MI, Crawford County, MI, Emmet County, MI, Genesee County, MI, Gladwin County, MI, Grand Traverse County, MI, Gratiot County, MI, Huron County, MI, Ionia County, MI, Iosco County, MI, Isabella County, MI, Kalkaska County, MI, Kent County, MI, Lake County, MI, Lapeer County, MI, Leelanau County, MI, Mackinac County, MI, Manistee County, MI, Mason County, MI, Mecosta County, MI, Midland County, MI, Missaukee County, MI, Montcalm County, MI, Montmorency County, MI, Muskegon County, MI, Newaygo County, MI, Oceana County, MI, Ogemaw County, MI, Osceola County, MI, Oscoda County, MI, Otsego County, MI, Ottawa County, MI, Presque Isle County, MI, Roscommon County, MI, Saginaw County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Wexford County, MI, Columbia County, WI, Dodge County, WI, Fond du Lac County, WI, Green Lake County, WI, Jefferson County, WI, Marquette County, WI, Milwaukee County, WI, Ozaukee County, WI, Sheboygan County, WI, Washington County, WI, Waukesha County, WI

The radar

The NCL Michigan radar (KAPX), 47 km from the middle of the area, began a volume at 13:47 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 21, 9:49 AM EDTSevere Thunderstorm WarningMKXMarquette26 min
Jul 21, 10:08 AM EDTSevere Thunderstorm WarningMKXColumbia, Dodge, Green Lake, Marquette37 min
Jul 21, 11:23 AM EDTSevere Thunderstorm WarningAPXGrand Traverse, Wexford37 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, 1.8 hours before the alert went out and 231 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 2016-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1904 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 2016-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 152 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
1904 J/kg
Mixed-layer CIN
-96 J/kg
Mixed-layer LCL
686 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
152 m²/s²
0-3 km storm-relative helicity
154 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
Jul 21, 4:54 AM EDTMesoscale DiscussionSPCBaraga, Dickinson, Gogebic, Houghton, Iron, Keweenaw and 2 more2 hr
Jul 21, 5:31 AM EDTSevere Thunderstorm WatchSPCAlger, Baraga, Delta, Dickinson, Gogebic, Houghton and 7 more6 hr
Jul 21, 7:39 AM EDTMesoscale DiscussionSPCAlger, Baraga, Delta, Dickinson, Houghton, Iron and 3 more2 hr
Jul 21, 9:28 AM EDTMesoscale DiscussionSPCAlcona, Alpena, Antrim, Arenac, Bay, Benzie and 42 more2 hr
Jul 21, 12:19 PM EDTMesoscale DiscussionSPCAlcona, Alpena, Arenac, Bay, Cheboygan, Clare and 30 more116 min
Jul 21, 2:23 PM EDTMesoscale DiscussionSPCBranch, Calhoun, Cass, Hillsdale, Jackson, Lenawee and 5 more2 hr
Jul 21, 1:32 AM EDTSevere Thunderstorm WatchSPCAshland, Barron, Bayfield, Burnett, Chippewa, Douglas and 8 more6 hr
Jul 21, 3:30 AM EDTMesoscale DiscussionSPCBayfield, Burnett, Douglas, Washburn2 hr
Jul 21, 4:20 PM EDTMesoscale DiscussionSPCAdams, Buffalo, Columbia, Eau Claire, Iowa, Jackson and 9 more115 min
Jul 21, 5:26 PM EDTSevere Thunderstorm WatchSPCColumbia, Dane, Dodge, Fond du Lac, Green, Green Lake and 13 more5 hr
Jul 21, 6:42 PM EDTMesoscale DiscussionSPCColumbia, Dane, Dodge, Fond du Lac, Green, Green Lake and 12 more93 min

Nearby

Severe Thunderstorm Watches in Michigan, 2016Severe Thunderstorm Watches in Wisconsin, 2016Every severe thunderstorm watch in 2016

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.