Alert archive / Michigan / Severe Thunderstorm Watches in 2009

Severe Thunderstorm Watch 182

April 25, 200913 counties in Indiana; 29 counties in Michigan; Fulton County, Williams County, Ohio

The Storm Prediction Center issued this severe thunderstorm watch at Apr 25, 2009, 3:39 PM EDT for 13 counties in Indiana; 29 counties in Michigan; Fulton County, Williams County, Ohio. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 25, 2009, 3:39 PM EDT (19:39 UTC)
Expired
Apr 25, 2009, 10:00 PM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 44 counties

DeKalb County, IN, Elkhart County, IN, Fulton County, IN, Kosciusko County, IN, LaGrange County, IN, LaPorte County, IN, Marshall County, IN, Noble County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Whitley County, IN, Allegan County, MI, Barry County, MI, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Hillsdale County, MI, Ingham County, MI, Ionia County, MI, Jackson County, MI, Kalamazoo County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Monroe County, MI, Oakland County, MI, Saginaw County, MI, Saint Clair County, MI, Saint Joseph County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Van Buren County, MI, Washtenaw County, MI, Wayne County, MI, Fulton County, OH, Williams County, OH

The radar

The Detroit radar (KDTX), 48 km from the middle of the area, began a volume at 19:41 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
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 25, 4:30 PM EDTSevere Thunderstorm WarningGRRBarry, Calhoun, Eaton, Kalamazoo45 min
Apr 25, 4:39 PM EDTSevere Thunderstorm WarningGRRCalhoun, Kalamazoo36 min
Apr 25, 5:00 PM EDTSevere Thunderstorm WarningGRRCalhoun, Clinton, Eaton, Ingham, Jackson60 min
Apr 25, 5:27 PM EDTSevere Thunderstorm WarningDTXLivingston, Shiawassee, Washtenaw93 min
Apr 25, 5:56 PM EDTSevere Thunderstorm WarningGRRIngham, Jackson22 min
Apr 25, 5:59 PM EDTSevere Thunderstorm WarningDTXGenesee, Oakland68 min
Apr 25, 6:12 PM EDTSevere Thunderstorm WarningGRRClinton, Gratiot21 min
Apr 25, 6:21 PM EDTSevere Thunderstorm WarningDTXWayne71 min
Apr 25, 7:04 PM EDTSevere Thunderstorm WarningDTXMacomb, Saint Clair41 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

Detroit, MI (KDTX), launched 12:00Z, 7.7 hours before the alert went out and 52 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 2009-04-25Temperature 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 2009-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 221 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1402 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
221 m²/s²
0-3 km storm-relative helicity
222 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
Apr 25, 2:55 PM EDTMesoscale DiscussionSPCElkhart, Kosciusko, LaGrange, Lake, LaPorte, Marshall and 5 more95 min
Apr 25, 7:15 PM EDTMesoscale DiscussionSPCDeKalb, Elkhart, Kosciusko, LaGrange, LaPorte, Marshall and 4 more60 min
Apr 24, 8:42 PM EDTMesoscale DiscussionSPCDickinson, Gogebic, Iron, Ontonagon63 min
Apr 25, 10:23 AM EDTMesoscale DiscussionSPCAlcona, Alpena, Arenac, Barry, Bay, Clare and 27 more2 hr
Apr 25, 10:44 AM EDTSevere Thunderstorm WatchSPCAlcona, Allegan, Alpena, Arenac, Barry, Bay and 35 more5 hr
Apr 25, 11:55 AM EDTMesoscale DiscussionSPCAlcona, Alpena, Arenac, Barry, Bay, Calhoun and 31 more95 min
Apr 25, 1:06 PM EDTMesoscale DiscussionSPCArenac, Barry, Bay, Calhoun, Clare, Clinton and 26 more84 min

Nearby

Severe Thunderstorm Watches in Michigan, 2009Severe Thunderstorm Watches in Indiana, 2009Severe Thunderstorm Watches in Ohio, 2009Every severe thunderstorm watch in 2009

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.