Alert archive / Iowa / Mesoscale Discussions in 2012

Mesoscale Discussion 1594

July 25, 20127 counties in Illinois; 23 counties in Iowa; Lafayette County, Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 25, 2012, 8:40 PM CDT for 7 counties in Illinois; 23 counties in Iowa; Lafayette County, Wisconsin. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Jul 25, 2012, 8:40 PM CDT (01:40 UTC)
Expired
Jul 25, 2012, 9:45 PM CDT
In force
65 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 31 counties

Benton County, IA, Buchanan County, IA, Cedar County, IA, Clayton County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Louisa County, IA, Mahaska County, IA, Monroe County, IA, Muscatine County, IA, Poweshiek County, IA, Scott County, IA, Wapello County, IA, Washington County, IA, Carroll County, IL, Henry County, IL, Jo Daviess County, IL, Mercer County, IL, Rock Island County, IL, Stephenson County, IL, Whiteside County, IL, Lafayette County, WI

The radar

The Quad Cities radar (KDVN), 67 km from the middle of the area, began a volume at 01:40 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 00:00Z, 1.7 hours before the alert went out and 73 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 00:00Z on 2012-07-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 700 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 00:00Z on 2012-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 84 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
700 J/kg
Mixed-layer CIN
-149 J/kg
Mixed-layer LCL
2702 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
84 m²/s²
0-3 km storm-relative helicity
158 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

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
Jul 25, 8:57 PM CDTSevere Thunderstorm WatchSPCCarroll, Jo Daviess, Lee, Ogle, Rock Island, Stephenson and 2 more6 hr
Jul 25, 11:34 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, DeKalb, Henry, Jo Daviess and 7 more86 min
Jul 26, 1:40 AM CDTMesoscale DiscussionSPCBoone, Bureau, Cook, DeKalb, DuPage, Grundy and 15 more65 min
Jul 26, 12:09 PM CDTMesoscale DiscussionSPCBoone, McHenry2 hr
Jul 26, 1:25 PM CDTMesoscale DiscussionSPCAlexander, Bond, Clay, Clinton, Cumberland, Edwards and 27 more65 min
Jul 26, 1:46 PM CDTSevere Thunderstorm WatchSPCAlexander, Clark, Clay, Clinton, Crawford, Cumberland and 28 more10 hr
Jul 26, 3:55 PM CDTMesoscale DiscussionSPCAlexander, Clay, Clinton, Crawford, Edwards, Franklin and 24 more35 min
Jul 26, 6:29 PM CDTMesoscale DiscussionSPCAlexander, Gallatin, Hamilton, Hardin, Johnson, Massac and 5 more61 min
Jul 25, 7:20 PM CDTMesoscale DiscussionSPCBlack Hawk, Boone, Bremer, Butler, Calhoun, Carroll and 25 more85 min
Jul 25, 7:21 PM CDTMesoscale DiscussionSPCCass, Fremont, Mills, Montgomery, Page, Pottawattamie and 1 more54 min
Jul 25, 8:28 PM CDTMesoscale DiscussionSPCBrown, Calumet, Kewaunee, Manitowoc, Sheboygan92 min
Jul 25, 11:09 PM CDTMesoscale DiscussionSPCOzaukee, Sheboygan96 min

Nearby

Mesoscale Discussions in Iowa, 2012Mesoscale Discussions in Illinois, 2012Mesoscale Discussions in Wisconsin, 2012Every mesoscale discussion 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.