Alert archive / Iowa / Mesoscale Discussions in 2003

Mesoscale Discussion 2041

July 31, 200319 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at Jul 31, 2003, 11:14 PM CDT for 19 counties in Iowa. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 31, 2003, 11:14 PM CDT (04:14 UTC)
Expired: Aug 1, 2003, 1:15 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Benton County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Chickasaw County, IA, Franklin County, IA, Grundy County, IA, Hamilton County, IA, Hardin County, IA, Jasper County, IA, Linn County, IA, Marshall County, IA, Polk County, IA, Story County, IA, Tama County, IA, Webster County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 77 km from the middle of the area, began a volume at 04:17 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

Davenport, (KDVN), launched 00:00Z, 4.2 hours before the alert went out and 247 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 857 J/kg
Mixed-layer CIN: -64 J/kg
Mixed-layer LCL: 1878 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 102 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

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.

Issued	Product	Office	Counties	Lasted
Jul 31, 8:19 PM CDT	Mesoscale Discussion	SPC	Allamakee, Benton, Black Hawk, Bremer, Buchanan, Cedar and 11 more	116 min
Aug 1, 10:59 AM CDT	Mesoscale Discussion	SPC	Des Moines, Henry, Louisa, Muscatine	2 hr
Aug 1, 2:00 PM CDT	Severe Thunderstorm Watch	SPC	Des Moines, Henry, Jefferson, Lee, Louisa, Scott and 1 more	6 hr
Aug 1, 5:49 PM CDT	Mesoscale Discussion	SPC	Des Moines, Henry, Lee, Louisa, Scott	86 min

Nearby

Mesoscale Discussions in Iowa, 2003 Every mesoscale discussion in 2003

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.