Alert archive / Iowa / Mesoscale Discussions in 2018
Mesoscale Discussion 1476
The Storm Prediction Center issued this mesoscale discussion at Sep 18, 2018, 3:06 PM CDT for 19 counties in Iowa; Nodaway County, Worth County, Missouri; 13 counties in Nebraska. It was in force for 84 min.
The area
The outline as issued.
The facts
- Issued
- Sep 18, 2018, 3:06 PM CDT (20:06 UTC)
- Expired
- Sep 18, 2018, 4:30 PM CDT
- In force
- 84 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
All 34 counties
Adair County, IA, Adams County, IA, Audubon County, IA, Cass County, IA, Clarke County, IA, Decatur County, IA, Fremont County, IA, Guthrie County, IA, Harrison County, IA, Madison County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Ringgold County, IA, Shelby County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Nodaway County, MO, Worth County, MO, Butler County, NE, Cass County, NE, Colfax County, NE, Dodge County, NE, Douglas County, NE, Lancaster County, NE, Otoe County, NE, Platte County, NE, Polk County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Washington County, NE
The radar
The Omaha radar (KOAX), 39 km from the middle of the area, began a volume at 20:09 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, 8.1 hours before the alert went out and 40 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
- 1380 J/kg
- Mixed-layer CIN
- -109 J/kg
- Mixed-layer LCL
- 1445 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- -3 m²/s²
- 0-3 km storm-relative helicity
- -25 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 |
|---|---|---|---|---|
| Sep 18, 2:48 AM CDT | Mesoscale Discussion | SPC | Lyon | 2 hr |
| Sep 18, 5:48 AM CDT | Mesoscale Discussion | SPC | Dickinson, Emmet, Lyon, Osceola | 2 hr |
| Sep 18, 5:11 PM CDT | Mesoscale Discussion | SPC | Fremont, Mills, Montgomery, Page, Ringgold, Taylor | 64 min |
| Sep 17, 7:49 PM CDT | Mesoscale Discussion | SPC | Antelope, Blaine, Boone, Boyd, Brown, Cedar and 16 more | 116 min |
Nearby
Mesoscale Discussions in Iowa, 2018Mesoscale Discussions in Nebraska, 2018Mesoscale Discussions in Missouri, 2018Every mesoscale discussion in 2018
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.