Alert archive / Iowa / Mesoscale Discussions in 2016

Mesoscale Discussion 1652

September 6, 201621 counties in Iowa; Burt County, Dakota County, Thurston County, Nebraska

The Storm Prediction Center issued this mesoscale discussion at Sep 6, 2016, 10:45 PM CDT for 21 counties in Iowa; Burt County, Dakota County, Thurston County, Nebraska. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
Sep 6, 2016, 10:45 PM CDT (03:45 UTC)
Expired
Sep 6, 2016, 11:45 PM CDT
In force
60 min
Issued by
the Storm Prediction Center
All 24 counties

Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cerro Gordo County, IA, Cherokee County, IA, Crawford County, IA, Hancock County, IA, Harrison County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Monona County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Sac County, IA, Webster County, IA, Winnebago County, IA, Woodbury County, IA, Worth County, IA, Wright County, IA, Burt County, NE, Dakota County, NE, Thurston County, NE

The radar

The Des Moines radar (KDMX), 142 km from the middle of the area, began a volume at 03:47 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, 3.8 hours before the alert went out and 190 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 2016-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2597 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 2016-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 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
2597 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
1252 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
1.5
Supercell composite
9.8

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 6, 7:00 PM CDTSevere Thunderstorm WatchSPCAdair, Adams, Audubon, Black Hawk, Boone, Bremer and 30 more7 hr
Sep 6, 8:16 PM CDTMesoscale DiscussionSPCAllamakee, Winneshiek89 min
Sep 7, 1:00 PM CDTMesoscale DiscussionSPCCedar, Clinton, Des Moines, Dubuque, Henry, Jackson and 9 more3 hr
Sep 7, 2:47 PM CDTMesoscale DiscussionSPCAdams, Appanoose, Clarke, Decatur, Fremont, Mills and 6 more2 hr

Nearby

Mesoscale Discussions in Iowa, 2016Mesoscale Discussions in Nebraska, 2016Every mesoscale discussion in 2016

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.