Alert archive / Iowa / Mesoscale Discussions in 2009

Mesoscale Discussion 978

June 7, 200931 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at Jun 7, 2009, 5:21 PM CDT for 31 counties in Iowa. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued
Jun 7, 2009, 5:21 PM CDT (22:21 UTC)
Expired
Jun 7, 2009, 6:15 PM CDT
In force
54 min
Issued by
the Storm Prediction Center
All 31 counties

Boone County, IA, Bremer County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cerro Gordo County, IA, Cherokee County, IA, Clay County, IA, Crawford County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Marshall County, IA, O'Brien County, IA, Palo Alto County, IA, Pocahontas County, IA, Sac County, IA, Story County, IA, Tama County, IA, Webster County, IA, Winnebago County, IA, Woodbury County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 101 km from the middle of the area, began a volume at 22:22 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, 10.4 hours before the alert went out and 201 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 2009-06-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 83 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 2009-06-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 318 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
83 J/kg
Mixed-layer CIN
-238 J/kg
Mixed-layer LCL
460 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
318 m²/s²
0-3 km storm-relative helicity
238 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.2

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
Jun 6, 9:01 PM CDTSevere Thunderstorm WatchSPCFremont, Mills, Montgomery, Page6 hr
Jun 6, 11:04 PM CDTMesoscale DiscussionSPCAdams, Fremont, Mills, Montgomery, Page, Taylor86 min
Jun 6, 11:16 PM CDTSevere Thunderstorm WatchSPCAdair, Adams, Appanoose, Audubon, Boone, Carroll and 24 more6 hr
Jun 7, 12:44 AM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Boone, Carroll and 36 more61 min
Jun 7, 4:45 AM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Cass, Cedar, Clarke and 31 more30 min
Jun 7, 11:16 AM CDTMesoscale DiscussionSPCBuena Vista, Calhoun, Carroll, Cerro Gordo, Cherokee, Clay and 24 more119 min
Jun 7, 2:36 PM CDTMesoscale DiscussionSPCFremont, Mills, Montgomery, Page, Taylor114 min
Jun 7, 3:45 PM CDTTornado WatchSPCAdair, Adams, Audubon, Cass, Clarke, Dallas and 12 more7 hr
Jun 7, 5:31 PM CDTMesoscale DiscussionSPCAppanoose, Davis, Henry, Iowa, Jefferson, Keokuk and 10 more59 min
Jun 7, 5:44 PM CDTTornado WatchSPCAppanoose, Boone, Davis, Jasper, Lucas, Mahaska and 10 more6 hr

Nearby

Mesoscale Discussions in Iowa, 2009Every mesoscale discussion in 2009

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.