Alert archive / Michigan / Mesoscale Discussions in 2009

Mesoscale Discussion 564

April 25, 2009Cook County, Will County, Illinois; 11 counties in Indiana; 31 counties in Michigan

The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2009, 1:55 PM CDT for Cook County, Will County, Illinois; 11 counties in Indiana; 31 counties in Michigan. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Apr 25, 2009, 1:55 PM CDT (18:55 UTC)
Expired
Apr 25, 2009, 3:30 PM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 44 counties

Cook County, IL, Will County, IL, Elkhart County, IN, Kosciusko County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Noble County, IN, Porter County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Allegan County, MI, Arenac County, MI, Barry County, MI, Bay County, MI, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Gratiot County, MI, Hillsdale County, MI, Huron County, MI, Ingham County, MI, Ionia County, MI, Jackson County, MI, Kalamazoo County, MI, Kent County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Midland County, MI, Montcalm County, MI, Oakland County, MI, Saginaw County, MI, Saint Joseph County, MI, Shiawassee County, MI, Tuscola County, MI, Van Buren County, MI, Washtenaw County, MI

The radar

The Grand Rapids radar (KGRR), 54 km from the middle of the area, began a volume at 18:58 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 6.9 hours before the alert went out and 157 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

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 25, 5:32 PM CDTMesoscale DiscussionSPCAdams, Boone, Brown, Bureau, Carroll, Cass and 40 more73 min
Apr 25, 2:39 PM CDTSevere Thunderstorm WatchSPCDeKalb, Elkhart, Fulton, Kosciusko, LaGrange, LaPorte and 7 more6 hr
Apr 25, 6:15 PM CDTMesoscale DiscussionSPCDeKalb, Elkhart, Kosciusko, LaGrange, LaPorte, Marshall and 4 more60 min
Apr 24, 7:42 PM CDTMesoscale DiscussionSPCDickinson, Gogebic, Iron, Ontonagon63 min
Apr 25, 9:23 AM CDTMesoscale DiscussionSPCAlcona, Alpena, Arenac, Barry, Bay, Clare and 27 more2 hr
Apr 25, 9:44 AM CDTSevere Thunderstorm WatchSPCAlcona, Allegan, Alpena, Arenac, Barry, Bay and 35 more5 hr
Apr 25, 10:55 AM CDTMesoscale DiscussionSPCAlcona, Alpena, Arenac, Barry, Bay, Calhoun and 31 more95 min
Apr 25, 12:06 PM CDTMesoscale DiscussionSPCArenac, Barry, Bay, Calhoun, Clare, Clinton and 26 more84 min

Nearby

Mesoscale Discussions in Michigan, 2009Mesoscale Discussions in Indiana, 2009Mesoscale Discussions in Illinois, 2009Every mesoscale discussion 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.