Alert archive / Iowa / Mesoscale Discussions in 2017
Mesoscale Discussion 1543
The Storm Prediction Center issued this mesoscale discussion at Aug 21, 2017, 2:35 PM CDT for 4 states. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- Aug 21, 2017, 2:35 PM CDT (19:35 UTC)
- Expired
- Aug 21, 2017, 4:00 PM CDT
- In force
- 85 min
- Issued by
- the Storm Prediction Center
All 55 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, Dickinson County, IA, Emmet County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Harrison County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Lyon County, IA, Monona County, IA, O'Brien County, IA, Osceola County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Sac County, IA, Shelby County, IA, Sioux County, IA, Webster County, IA, Winnebago County, IA, Woodbury County, IA, Wright County, IA, Cottonwood County, MN, Jackson County, MN, Martin County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Antelope County, NE, Boone County, NE, Burt County, NE, Cedar County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Garfield County, NE, Madison County, NE, Pierce County, NE, Stanton County, NE, Thurston County, NE, Wayne County, NE, Wheeler County, NE, Union County, SD
The radar
The Sioux Falls radar (KFSD), 125 km from the middle of the area, began a volume at 19:39 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 12:00Z, 7.6 hours before the alert went out and 136 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.
- Mixed-layer CAPE
- 107 J/kg
- Mixed-layer CIN
- -350 J/kg
- Mixed-layer LCL
- 1132 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 209 m²/s²
- 0-3 km storm-relative helicity
- 421 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 11.7
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 11:14 PM CDT | Mesoscale Discussion | SPC | Adair, Audubon, Boone, Calhoun, Carroll, Cass and 15 more | 91 min |
| Aug 21, 11:12 AM CDT | Mesoscale Discussion | SPC | Lyon, Plymouth, Sioux | 93 min |
| Aug 21, 11:33 AM CDT | Severe Thunderstorm Watch | SPC | Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 6 more | 7 hr |
| Aug 21, 5:31 AM CDT | Mesoscale Discussion | SPC | Hand, Hughes, Hyde, Potter, Stanley, Sully | 89 min |
| Aug 21, 8:27 AM CDT | Mesoscale Discussion | SPC | Aurora, Beadle, Brule, Buffalo, Charles Mix, Davison and 16 more | 2 hr |
| Aug 21, 8:55 AM CDT | Severe Thunderstorm Watch | SPC | Aurora, Brule, Buffalo, Charles Mix, Davison, Douglas and 8 more | 5 hr |
Nearby
Mesoscale Discussions in Iowa, 2017Mesoscale Discussions in Nebraska, 2017Mesoscale Discussions in Minnesota, 2017Every mesoscale discussion in 2017
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.