Alert archive / Iowa / Mesoscale Discussions in 2004

Mesoscale Discussion 731

May 17, 20044 states

The Storm Prediction Center issued this mesoscale discussion at May 17, 2004, 8:20 PM CDT for 4 states. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
May 17, 2004, 8:20 PM CDT (01:20 UTC)
Expired
May 17, 2004, 9:15 PM CDT
In force
55 min
Issued by
the Storm Prediction Center
All 43 counties

Adams County, IA, Appanoose County, IA, Clarke County, IA, Davis County, IA, Decatur County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Keokuk County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Monroe County, IA, Page County, IA, Poweshiek County, IA, Ringgold County, IA, Taylor County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Atchison County, KS, Brown County, KS, Doniphan County, KS, Nemaha County, KS, Andrew County, MO, Atchison County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Sullivan County, MO, Worth County, MO, Nemaha County, NE, Pawnee County, NE, Richardson County, NE

The radar

The Des Moines radar (KDMX), 130 km from the middle of the area, began a volume at 01:21 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, 1.3 hours before the alert went out and 200 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 2004-05-18Temperature 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, Omaha, NE at 00:00Z on 2004-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -35 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
704 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
-35 m²/s²
0-3 km storm-relative helicity
139 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

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.

IssuedProductOfficeCountiesLasted
May 17, 7:15 PM CDTSevere Thunderstorm WatchSPCBenton, Black Hawk, Buchanan, Cedar, Clayton, Clinton and 17 more5 hr
May 17, 7:59 PM CDTMesoscale DiscussionSPCBarton, Butler, Clark, Clay, Dickinson, Edwards and 40 more2 hr
May 18, 6:22 AM CDTMesoscale DiscussionSPCCoffey, Douglas, Franklin, Jefferson, Johnson, Leavenworth and 4 more113 min
May 18, 2:22 PM CDTMesoscale DiscussionSPCClay, Dickinson, Douglas, Ellsworth, Geary, Jackson and 10 more113 min
May 18, 4:28 PM CDTMesoscale DiscussionSPCAllen, Barber, Butler, Elk, Greenwood, Harvey and 6 more2 hr
May 18, 6:27 PM CDTMesoscale DiscussionSPCAnderson, Atchison, Chase, Coffey, Douglas, Franklin and 11 more2 hr
May 18, 10:26 AM CDTMesoscale DiscussionSPCAudrain, Boone, Callaway, Lincoln, Monroe, Montgomery and 6 more3 hr
May 18, 12:00 PM CDTSevere Thunderstorm WatchSPCCrawford, Franklin, Gasconade, Jefferson, Lincoln, Marion and 7 more7 hr
May 18, 2:38 PM CDTMesoscale DiscussionSPCJefferson, Saint Louis, City of Saint Louis2 hr
May 17, 11:48 PM CDTMesoscale DiscussionSPCAdams, Clay, Fillmore, Franklin, Furnas, Harlan and 4 more2 hr

Nearby

Mesoscale Discussions in Iowa, 2004Mesoscale Discussions in Missouri, 2004Mesoscale Discussions in Kansas, 2004Every mesoscale discussion in 2004

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.