Alert archive / Iowa / Mesoscale Discussions in 2007

Mesoscale Discussion 1650

August 4, 200721 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at Aug 4, 2007, 9:22 PM CDT for 21 counties in Iowa. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Aug 4, 2007, 9:22 PM CDT (02:22 UTC)
Expired
Aug 4, 2007, 10:15 PM CDT
In force
53 min
Issued by
the Storm Prediction Center
All 21 counties

Audubon County, IA, Boone County, IA, Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cherokee County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Humboldt County, IA, Ida County, IA, Jasper County, IA, Palo Alto County, IA, Pocahontas County, IA, Polk County, IA, Sac County, IA, Story County, IA, Webster County, IA

The radar

The Des Moines radar (KDMX), 75 km from the middle of the area, began a volume at 02:23 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

Omaha, NE (KOAX), launched 00:00Z, 2.4 hours before the alert went out and 203 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 00:00Z on 2007-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1034 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 00:00Z on 2007-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 12 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
1034 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
1889 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
73 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

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
Aug 4, 7:42 PM CDTTornado WatchSPCAudubon, Boone, Buena Vista, Calhoun, Carroll, Cherokee and 16 more3 hr
Aug 4, 9:07 PM CDTMesoscale DiscussionSPCHarrison, Monona, Pottawattamie53 min
Aug 5, 3:54 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Benton, Cass, Cedar and 39 more96 min

Nearby

Mesoscale Discussions in Iowa, 2007Every mesoscale discussion in 2007

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.