Alert archive / Iowa / Mesoscale Discussions in 2005

Mesoscale Discussion 779

May 8, 200534 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at May 8, 2005, 3:05 PM CDT for 34 counties in Iowa. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
May 8, 2005, 3:05 PM CDT (20:05 UTC)
Expired
May 8, 2005, 4:30 PM CDT
In force
85 min
Issued by
the Storm Prediction Center
All 34 counties

Black Hawk County, IA, Boone County, IA, Bremer County, IA, Butler County, IA, Calhoun County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clarke County, IA, Dallas County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Humboldt County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Polk County, IA, Poweshiek County, IA, Story County, IA, Tama County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Webster County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 17 km from the middle of the area, began a volume at 20:05 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

Omaha, NE (KOAX), launched 12:00Z, 8.1 hours before the alert went out and 237 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, Omaha, NE at 12:00Z on 2005-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 446 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, Omaha, NE at 12:00Z on 2005-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 162 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
446 J/kg
Mixed-layer CIN
-93 J/kg
Mixed-layer LCL
704 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
162 m²/s²
0-3 km storm-relative helicity
122 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.0

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
May 7, 7:34 PM CDTMesoscale DiscussionSPCCherokee, Ida, Lyon, Monona, O'Brien, Osceola and 3 more116 min
May 7, 7:55 PM CDTSevere Thunderstorm WatchSPCLyon, Plymouth, Sioux6 hr
May 7, 11:07 PM CDTMesoscale DiscussionSPCDickinson, Lyon, O'Brien, Osceola, Plymouth, Sioux83 min
May 8, 1:10 PM CDTMesoscale DiscussionSPCLyon, Sioux3 hr
May 8, 1:50 PM CDTTornado WatchSPCBuena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 6 more7 hr
May 8, 2:30 PM CDTSevere Thunderstorm WatchSPCAudubon, Carroll, Crawford, Fremont, Harrison, Mills and 5 more7 hr
May 8, 5:27 PM CDTMesoscale DiscussionSPCBuena Vista, Cherokee, Clay, Crawford, Dickinson, Emmet and 12 more63 min
May 8, 5:30 PM CDTSevere Thunderstorm WatchSPCCalhoun, Emmet, Franklin, Hamilton, Hancock, Hardin and 7 more8 hr

Nearby

Mesoscale Discussions in Iowa, 2005Every mesoscale discussion in 2005

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.