Alert archive / Iowa / Mesoscale Discussions in 2013

Mesoscale Discussion 815

May 27, 20134 states

The Storm Prediction Center issued this mesoscale discussion at May 27, 2013, 1:40 AM CDT for 4 states. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
May 27, 2013, 1:40 AM CDT (06:40 UTC)
Expired
May 27, 2013, 3:15 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 37 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Cass County, IA, Fremont County, IA, Harrison County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Ringgold County, IA, Shelby County, IA, Taylor County, IA, Union County, IA, Brown County, KS, Doniphan County, KS, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Harrison County, MO, Holt County, MO, Nodaway County, MO, Worth County, MO, Burt County, NE, Cass County, NE, Douglas County, NE, Nemaha County, NE, Otoe County, NE, Richardson County, NE, Sarpy County, NE, Saunders County, NE, Washington County, NE

The radar

The Omaha radar (KOAX), 75 km from the middle of the area, began a volume at 06:42 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 00:00Z, 6.7 hours before the alert went out and 75 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 2013-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3377 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 2013-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 151 square meters per square second.1939Sfc1 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
3377 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
966 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
272 m²/s²
Significant tornado parameter
3.3
Supercell composite
16.4

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 26, 11:03 PM CDTSevere Thunderstorm WatchSPCFremont, Harrison, Mills, Monona, Montgomery, Page and 2 more6 hr
May 27, 2:51 AM CDTSevere Thunderstorm WatchSPCAdair, Adams, Audubon, Boone, Calhoun, Carroll and 23 more4 hr
May 27, 6:20 AM CDTMesoscale DiscussionSPCDecatur, Hardin, Jasper, Lucas, Marion, Marshall and 3 more85 min
May 27, 3:33 AM CDTSevere Thunderstorm WatchSPCAtchison, Brown, Doniphan, Jackson, Nemaha5 hr
May 27, 2:00 PM CDTMesoscale DiscussionSPCCheyenne, Decatur, Gove, Logan, Norton, Rawlins and 4 more60 min
May 27, 2:19 PM CDTSevere Thunderstorm WatchSPCCheyenne, Gove, Greeley, Logan, Rawlins, Sherman and 3 more6 hr
May 27, 3:23 PM CDTMesoscale DiscussionSPCCloud, Decatur, Ellis, Graham, Jewell, Lincoln and 9 more67 min
May 27, 4:49 PM CDTTornado WatchSPCClay, Cloud, Decatur, Dickinson, Ellis, Ellsworth and 20 more7 hr
May 27, 5:36 PM CDTMesoscale DiscussionSPCBarber, Barton, Butler, Chase, Comanche, Cowley and 19 more84 min
May 27, 5:41 PM CDTMesoscale DiscussionSPCCheyenne, Greeley, Logan, Scott, Sherman, Thomas and 2 more94 min
May 27, 6:53 PM CDTMesoscale DiscussionSPCClay, Cloud, Decatur, Dickinson, Ellis, Geary and 17 more2 hr
May 27, 2:39 PM CDTSevere Thunderstorm WatchSPCFranklin, Jefferson, Saint Charles, Saint Louis, City of Saint Louis5 hr
May 27, 5:54 PM CDTMesoscale DiscussionSPCPerry, Sainte Genevieve96 min
May 26, 7:33 PM CDTTornado WatchSPCAntelope, Blaine, Boone, Brown, Buffalo, Custer and 18 more4 hr
May 26, 9:07 PM CDTMesoscale DiscussionSPCAntelope, Blaine, Boone, Brown, Butler, Cedar and 24 more83 min

Nearby

Mesoscale Discussions in Iowa, 2013Mesoscale Discussions in Missouri, 2013Mesoscale Discussions in Nebraska, 2013Every mesoscale discussion in 2013

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.