Alert archive / Iowa / Severe Thunderstorm Warnings in 2018
Severe Thunderstorm Warning 255, NWS Omaha, NE
NWS Omaha, NE issued this severe thunderstorm warning at Sep 1, 2018, 5:36 AM CDT for Sarpy County, Nebraska; Mills County, Montgomery County, Pottawattamie County, Iowa. It was in force for 24 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Sep 1, 2018, 5:36 AM CDT (10:36 UTC)
- Expired
- Sep 1, 2018, 6:00 AM CDT
- In force
- 24 min
- Issued by
- NWS Omaha, NE
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Mills County, IA, Montgomery County, IA, Pottawattamie County, IA, Sarpy County, NE
The radar
The Omaha radar (KOAX), 67 km from the middle of the area, began a volume at 10:40 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, 10.6 hours before the alert went out and 67 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
- 2615 J/kg
- Mixed-layer CIN
- -112 J/kg
- Mixed-layer LCL
- 1197 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 186 m²/s²
- 0-3 km storm-relative helicity
- 306 m²/s²
- Significant tornado parameter
- 2.2
- Supercell composite
- 24.5
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Omaha, NE wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 1, 3:07 AM CDT, 2 hours 29 minutes earlier.
Area forecast discussion, Sep 1, 3:07 AM CDT, 2 hours 29 minutes before
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</html>Hazardous weather outlook, Sep 1, 5:26 AM CDT, 10 minutes before
Hazardous Weather Outlook National Weather Service Omaha/Valley NE 526 AM CDT Sat Sep 1 2018 IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034- 042>045-050>053-065>068-078-088>093-020030- Monona-Harrison-Shelby-Pottawattamie-Mills-Montgomery-Fremont- Page-Knox-Cedar-Thurston-Antelope-Pierce-Wayne-Boone-Madison- Stanton-Cuming-Burt-Platte-Colfax-Dodge-Washington-Butler- Saunders-Douglas-Sarpy-Seward-Lancaster-Cass-Otoe-Saline- Jefferson-Gage-Johnson-Nemaha-Pawnee-Richardson- 526 AM CDT Sat Sep 1 2018 This Hazardous Weather Outlook is for portions of southwest Iowa...west central Iowa...east central Nebraska...northeast Nebraska and southeast Nebraska. .DAY ONE...Today and Tonight Thunderstorms will be possible today, with the highest chances into mid morning and again later in the afternoon. A few storms could approach severe limits. Hail, strong winds and locally heavy rain would be the main hazards. Thunderstorm chances will be higher this evening and into tonight. The chance of severe storms seems to be highest from about 6 pm to 10 pm. Storms could produce large hail and damaging winds, along with areas of heavy rain. Locations that received heavy rain recently could see some flooding tonight, if heavy rain occurs again in those areas. Minor flooding will continue along the Missouri River upstream of Lewis and Clark Lake in northwest Knox county. .DAYS TWO THROUGH SEVEN...Sunday through Friday Scattered thunderstorms remain in the forecast for Sunday through Monday. Some strong storms and areas of locally heavy rain will be possible, especially from late Sunday afternoon into Monday morning. night and again Sunday night. Some flash flooding could develop. Rainfall through Monday could reach 2 to 5 inches in some spots across east central Nebraska and western Iowa. The weather pattern should remain active through at least mid week, with a continued chance for thunderstorms just about every day. Minor flooding will continue along the Missouri River upstream of Lewis and Clark Lake in northwest Knox county. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected to be needed today or tonight.
In the hours before
Special weather statement, Sep 1, 2:29 AM CDT, 3 hours 7 minutes before
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</html>Special weather statement, Sep 1, 3:17 AM CDT, 2 hours 19 minutes before
Special Weather Statement
National Weather Service Omaha/Valley Nebraska
317 AM CDT SAT SEP 1 2018
NEZ031-032-042>044-050-010900-
Stanton NE-Madison NE-Platte NE-Butler NE-Colfax NE-Dodge NE-
317 AM CDT SAT SEP 1 2018
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN MADISON...COLFAX...
PLATTE...WEST CENTRAL DODGE...NORTHWESTERN BUTLER AND SOUTHWESTERN
STANTON COUNTIES UNTIL 400 AM CDT...
At 317 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 7 miles northwest of Monroe to 3 miles
northwest of Bellwood. Movement was northeast at 20 mph.
Nickel size hail and wind gusts up to 50 mph will be possible with
these storms.
Locations impacted include...
Columbus, Schuyler, Madison, Clarkson, Howells, Bellwood, Leigh,
Duncan, Platte Center, Monroe, Creston, Humphrey, Richland, Tarnov,
Cornlea, College View Trailer Park, Camp Pawnee, Lake North Babcock
Campground, Circle H Trailer Park and Camp Luther.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4195 9748 4174 9702 4167 9680 4128 9722
4140 9737 4137 9746 4150 9771 4153 9771
TIME...MOT...LOC 0817Z 212DEG 27KT 4157 9768 4137 9729
DEESpecial weather statement, Sep 1, 4:07 AM CDT, 1 hour 29 minutes before
Special Weather Statement National Weather Service Omaha/Valley Nebraska 407 AM CDT SAT SEP 1 2018 IAZ043-NEZ015-018-032>034-042>044-010945- Monona IA-Stanton NE-Thurston NE-Burt NE-Platte NE-Colfax NE- Cuming NE-Wayne NE-Dodge NE- 407 AM CDT SAT SEP 1 2018 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN MONONA... NORTHWESTERN BURT...SOUTHEASTERN WAYNE...CUMING...NORTHERN COLFAX... NORTHEASTERN PLATTE...NORTHWESTERN DODGE...THURSTON AND SOUTHEASTERN STANTON COUNTIES UNTIL 445 AM CDT... At 406 AM CDT, Doppler radar was tracking strong thunderstorms along a line extending from 3 miles north of Leigh to 3 miles east of Snyder. Movement was northeast at 25 mph. Wind gusts up to 50 mph will be possible with these storms. Locations impacted include... West Point, Onawa, Wisner, Pender, Scribner, Lyons, Walthill, Whiting, Beemer, Clarkson, Dodge, Howells, Bancroft, Decatur, Leigh, Pilger, Snyder, Macy, Oakland and Rosalie. PRECAUTIONARY/PREPAREDNESS ACTIONS... These storms may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. && LAT...LON 4213 9597 4166 9667 4172 9738 4221 9688 TIME...MOT...LOC 0906Z 222DEG 36KT 4176 9724 4171 9671 DEE
Local storm report, Sep 1, 5:14 AM CDT, 22 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
514 AM CDT SAT SEP 1 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1150 PM HAIL 4 NNE COUNCIL BLUFFS 41.29N 95.83W
08/31/2018 E1.00 INCH POTTAWATTAMIE IA PUBLIC
HAIL UP TO QUARTER SIZE NORTHEAST COUNCIL BLUFFS NEAR
SPENCER AVE.
&&Special weather statement, Sep 1, 5:20 AM CDT, 16 minutes before
Special Weather Statement
National Weather Service Omaha/Valley Nebraska
520 AM CDT SAT SEP 1 2018
IAZ069-NEZ052-053-011100-
Pottawattamie IA-Sarpy NE-Douglas NE-
520 AM CDT SAT SEP 1 2018
...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL POTTAWATTAMIE...
NORTHEASTERN SARPY AND EASTERN DOUGLAS COUNTIES UNTIL 600 AM CDT...
At 520 AM CDT, Doppler radar was tracking a strong thunderstorm over
southern Omaha, moving east at 20 mph.
Dime size hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Omaha, Council Bluffs, Bellevue, Papillion, La Vista, Ralston,
Oakland, Treynor, Underwood, Carson, Macedonia, Carter Lake, Boys
Town, Crescent, McClelland, Old Town Park, Lake Manawa State Park,
Chalco and Narrows River Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
office in Omaha.
&&
LAT...LON 4116 9580 4116 9588 4115 9589 4113 9613
4132 9618 4146 9543 4119 9536
TIME...MOT...LOC 1020Z 259DEG 33KT 4124 9605
DEESpecial weather statement, Sep 1, 5:23 AM CDT, 13 minutes before
Special Weather Statement
National Weather Service Omaha/Valley Nebraska
523 AM CDT SAT SEP 1 2018
IAZ079-090-091-NEZ051>053-066>068-091-011100-
Mills IA-Page IA-Fremont IA-Saunders NE-Cass NE-Sarpy NE-Otoe NE-
Lancaster NE-Douglas NE-Nemaha NE-
523 AM CDT SAT SEP 1 2018
...SIGNIFICANT WEATHER ADVISORY FOR FREMONT...SOUTHWESTERN MILLS...
SOUTHERN PAGE...SARPY...NORTHEASTERN LANCASTER...NORTHEASTERN
NEMAHA...EASTERN OTOE...WESTERN DOUGLAS...SOUTHEASTERN SAUNDERS AND
CASS COUNTIES UNTIL 600 AM CDT...
At 523 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 8 miles northwest of Greenwood to 3 miles east
of Rockport. Movement was northeast at 35 mph.
Wind gusts up to 50 mph will be possible with these storms.
Locations impacted include...
Southwestern Omaha, Bellevue, Papillion, La Vista, Nebraska City,
Plattsmouth, Ralston, Glenwood, Shenandoah, Gretna, Waverly, Ashland,
Valley, Springfield, Hamburg, Yutan, Sidney, Louisville, Weeping
Water and Peru.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
office in Omaha.
&&
LAT...LON 4059 9493 4057 9497 4059 9576 4057 9578
4053 9577 4052 9570 4056 9567 4052 9566
4051 9569 4047 9569 4046 9565 4044 9565
4102 9671 4138 9635
TIME...MOT...LOC 1023Z 225DEG 31KT 4103 9657 4041 9545
DEEThe office that day
Everything else NWS Omaha, NE issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 1, 2:29 AM CDT | Special Weather Statement | OAX | Platte | 46 min |
| Sep 1, 2:50 AM CDT | Severe Thunderstorm Warning | OAX | Madison, Platte | 25 min |
| Sep 1, 3:17 AM CDT | Special Weather Statement | OAX | Colfax, Platte | 43 min |
| Sep 1, 4:07 AM CDT | Special Weather Statement | OAX | Cuming, Stanton, Thurston | 38 min |
| Sep 1, 5:20 AM CDT | Special Weather Statement | OAX | Douglas | 40 min |
| Sep 1, 5:23 AM CDT | Special Weather Statement | OAX | Cass, Sarpy | 37 min |
| Sep 1, 5:15 PM CDT | Flash Flood Watch | OAX | Butler, Cass, Douglas, Gage, Jefferson, Johnson and 10 more | 44 hr |
| Aug 31, 9:33 PM CDT | Special Weather Statement | OAX | Pottawattamie | 27 min |
| Aug 31, 11:19 PM CDT | Special Weather Statement | OAX | Mills | 26 min |
| Aug 31, 11:53 PM CDT | Special Weather Statement | OAX | Pottawattamie | 37 min |
| Aug 31, 11:54 PM CDT | Special Weather Statement | OAX | Pottawattamie | 36 min |
| Sep 1, 12:22 AM CDT | Special Weather Statement | OAX | Mills | 23 min |
| Sep 1, 12:24 AM CDT | Special Weather Statement | OAX | Pottawattamie | 36 min |
| Sep 1, 12:42 AM CDT | Special Weather Statement | OAX | Montgomery | 33 min |
| Sep 1, 12:54 AM CDT | Special Weather Statement | OAX | Pottawattamie | 36 min |
| Sep 1, 1:10 AM CDT | Severe Thunderstorm Warning | OAX | Montgomery | 35 min |
| Sep 1, 1:38 AM CDT | Special Weather Statement | OAX | Cass | 37 min |
| Sep 1, 2:16 AM CDT | Special Weather Statement | OAX | Cass | 29 min |
| Sep 1, 5:58 AM CDT | Severe Thunderstorm Warning | OAX | Mills, Montgomery, Pottawattamie | 32 min |
| Sep 1, 6:09 AM CDT | Special Weather Statement | OAX | Montgomery | 36 min |
| Sep 1, 6:19 AM CDT | Severe Thunderstorm Warning | OAX | Montgomery, Pottawattamie | 41 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 2018Severe Thunderstorm Warnings in Nebraska, 2018Every severe thunderstorm warning 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.