Alert archive / Wisconsin / Mesoscale Discussions in 2009

Mesoscale Discussion 557

April 24, 200929 counties in Iowa; 5 counties in Minnesota; 34 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2009, 9:40 PM CDT for 29 counties in Iowa; 5 counties in Minnesota; 34 counties in Wisconsin. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Apr 24, 2009, 9:40 PM CDT (02:40 UTC)
Expired
Apr 24, 2009, 10:45 PM CDT
In force
65 min
Issued by
the Storm Prediction Center
All 68 counties

Adair County, IA, Adams County, IA, Allamakee County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Chickasaw County, IA, Clayton County, IA, Dallas County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy County, IA, Hardin County, IA, Howard County, IA, Jasper County, IA, Madison County, IA, Marshall County, IA, Montgomery County, IA, Page County, IA, Polk County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Winneshiek County, IA, Fillmore County, MN, Houston County, MN, Olmsted County, MN, Wabasha County, MN, Winona County, MN, Adams County, WI, Buffalo County, WI, Chippewa County, WI, Clark County, WI, Crawford County, WI, Eau Claire County, WI, Florence County, WI, Forest County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Marinette County, WI, Marquette County, WI, Menominee County, WI, Monroe County, WI, Oconto County, WI, Oneida County, WI, Outagamie County, WI, Pepin County, WI, Portage County, WI, Price County, WI, Richland County, WI, Rusk County, WI, Shawano County, WI, Taylor County, WI, Trempealeau County, WI, Vernon County, WI, Vilas County, WI, Waupaca County, WI, Waushara County, WI, Wood County, WI

The radar

The La Crosse radar (KARX), 82 km from the middle of the area, began a volume at 02:43 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 nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 2.7 hours before the alert went out and 219 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, Minneapolis, MN at 00:00Z 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, Minneapolis, MN at 00:00Z on 2009-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
1032 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
181 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 24, 7:42 PM CDTMesoscale DiscussionSPCAdair, Adams, Allamakee, Benton, Black Hawk, Boone and 35 more63 min
Apr 25, 4:30 PM CDTSevere Thunderstorm WatchSPCAppanoose, Davis, Decatur, Monroe, Wapello, Wayne6 hr
Apr 25, 5:32 PM CDTMesoscale DiscussionSPCCedar, Clinton, Delaware, Des Moines, Dubuque, Henry and 11 more73 min

Nearby

Mesoscale Discussions in Wisconsin, 2009Mesoscale Discussions in Iowa, 2009Mesoscale Discussions in Minnesota, 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.