Alert archive / Michigan / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 407

June 18, 201231 counties in Michigan

The Storm Prediction Center issued this severe thunderstorm watch at Jun 18, 2012, 5:46 PM EDT for 31 counties in Michigan. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jun 18, 2012, 5:46 PM EDT (21:46 UTC)
Expired
Jun 18, 2012, 11:17 PM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 31 counties

Alcona County, MI, Alpena County, MI, Antrim County, MI, Arenac County, MI, Benzie County, MI, Charlevoix County, MI, Cheboygan County, MI, Clare County, MI, Crawford County, MI, Emmet County, MI, Gladwin County, MI, Grand Traverse County, MI, Iosco County, MI, Isabella County, MI, Kalkaska County, MI, Lake County, MI, Leelanau County, MI, Manistee County, MI, Mason County, MI, Mecosta County, MI, Missaukee County, MI, Montmorency County, MI, Newaygo County, MI, Oceana County, MI, Ogemaw County, MI, Osceola County, MI, Oscoda County, MI, Otsego County, MI, Presque Isle County, MI, Roscommon County, MI, Wexford County, MI

The radar

The NCL Michigan radar (KAPX), 41 km from the middle of the area, began a volume at 21:49 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
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
80%
One or more gusts of 65 knots or more
50%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 18, 6:47 PM EDTSevere Thunderstorm WarningAPXAntrim, Charlevoix, Emmet58 min
Jun 18, 7:13 PM EDTSevere Thunderstorm WarningAPXCheboygan, Emmet29 min
Jun 18, 7:40 PM EDTSevere Thunderstorm WarningAPXBenzie, Grand Traverse, Leelanau50 min
Jun 18, 7:42 PM EDTFlash Flood WarningAPXCharlevoix2 hr
Jun 18, 7:56 PM EDTSevere Thunderstorm WarningAPXAntrim, Kalkaska38 min
Jun 18, 9:43 PM EDTSevere Thunderstorm WarningAPXAlcona, Iosco, Ogemaw, Oscoda, Roscommon44 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

Alpena, MI (KAPX), launched 12:00Z, 9.8 hours before the alert went out and 216 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, Alpena, MI at 12:00Z on 2012-06-18Temperature 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, Alpena, MI at 12:00Z on 2012-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 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
1609 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
164 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 18, 10:33 AM EDTMesoscale DiscussionSPCBranch, Calhoun, Eaton, Genesee, Hillsdale, Ingham and 13 more2 hr
Jun 18, 12:40 PM EDTMesoscale DiscussionSPCDelta, Menominee2 hr
Jun 18, 1:24 PM EDTSevere Thunderstorm WatchSPCDelta, Dickinson, Iron, Menominee, Schoolcraft8 hr
Jun 18, 1:38 PM EDTMesoscale DiscussionSPCMonroe67 min
Jun 18, 4:50 PM EDTMesoscale DiscussionSPCAntrim, Benzie, Charlevoix, Cheboygan, Crawford, Emmet and 12 more85 min

Nearby

Severe Thunderstorm Watches in Michigan, 2012Every severe thunderstorm watch in 2012

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.