Alert archive / Illinois / Mesoscale Discussions in 2011

Mesoscale Discussion 1337

June 21, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Jun 21, 2011, 11:45 AM CDT for 4 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jun 21, 2011, 11:45 AM CDT (16:45 UTC)
Expired
Jun 21, 2011, 2:15 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
All 94 counties

Allamakee County, IA, Clayton County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Howard County, IA, Jackson County, IA, Jones County, IA, Scott County, IA, Winneshiek County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, Cook County, IL, DeKalb County, IL, DeWitt County, IL, DuPage County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Henry County, IL, Iroquois County, IL, Jo Daviess County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Logan County, IL, Marshall County, IL, Mason County, IL, McHenry County, IL, McLean County, IL, Menard County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Tazewell County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL, Woodford County, IL, Dodge County, MN, Fillmore County, MN, Goodhue County, MN, Houston County, MN, Olmsted County, MN, Wabasha County, MN, Winona County, MN, Adams County, WI, Buffalo County, WI, Calumet County, WI, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Eau Claire County, WI, Fond du Lac County, WI, Grant County, WI, Green County, WI, Green Lake County, WI, Iowa County, WI, Jackson County, WI, Jefferson County, WI, Juneau County, WI, Kenosha County, WI, La Crosse County, WI, Lafayette County, WI, Marquette County, WI, Milwaukee County, WI, Monroe County, WI, Ozaukee County, WI, Pepin County, WI, Pierce County, WI, Racine County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Sheboygan County, WI, Trempealeau County, WI, Vernon County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The Milwaukee radar (KMKX), 117 km from the middle of the area, began a volume at 16:45 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

Davenport, (KDVN), launched 12:00Z, 4.8 hours before the alert went out and 133 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, Davenport, at 12:00Z on 2011-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 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, Davenport, at 12:00Z on 2011-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -64 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
12 J/kg
Mixed-layer CIN
-422 J/kg
Mixed-layer LCL
1767 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
-64 m²/s²
0-3 km storm-relative helicity
-114 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
Jun 21, 12:56 PM CDTMesoscale DiscussionSPCAlexander, Bond, Calhoun, Christian, Clay, Clinton and 40 more64 min
Jun 21, 1:22 PM CDTTornado WatchSPCAlexander, Bond, Calhoun, Cass, Champaign, Christian and 49 more9 hr
Jun 21, 3:31 PM CDTMesoscale DiscussionSPCAlexander, Bond, Calhoun, Cass, Champaign, Christian and 46 more89 min
Jun 21, 4:56 PM CDTMesoscale DiscussionSPCBond, Brown, Bureau, Cass, Champaign, Christian and 68 more94 min
Jun 21, 5:42 PM CDTSevere Thunderstorm WatchSPCBoone, Bureau, Cook, DeKalb, DuPage, Ford and 23 more4 hr
Jun 20, 7:46 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Carroll, Cass, Crawford and 12 more59 min
Jun 20, 9:02 PM CDTMesoscale DiscussionSPCAudubon, Boone, Buena Vista, Calhoun, Carroll, Cherokee and 21 more58 min
Jun 20, 10:22 PM CDTMesoscale DiscussionSPCAppanoose, Benton, Black Hawk, Boone, Bremer, Buchanan and 48 more83 min
Jun 20, 10:58 PM CDTTornado WatchSPCAppanoose, Black Hawk, Bremer, Butler, Cerro Gordo, Davis and 17 more4 hr
Jun 21, 1:25 AM CDTMesoscale DiscussionSPCBenton, Black Hawk, Bremer, Buchanan, Butler, Chickasaw and 14 more35 min
Jun 21, 2:11 PM CDTTornado WatchSPCAnoka, Chisago, Dakota, Goodhue, Hennepin, Houston and 7 more7 hr

Nearby

Mesoscale Discussions in Illinois, 2011Mesoscale Discussions in Wisconsin, 2011Mesoscale Discussions in Iowa, 2011Every mesoscale discussion in 2011

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.