Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 58, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Jul 9, 2021, 12:28 PM CDT for 4 counties in Iowa. It was in force for 47 min. 6 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 9, 2021, 12:28 PM CDT (17:28 UTC)
- Expired
- Jul 9, 2021, 1:15 PM CDT
- In force
- 47 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Hail
- 1.25 in
- Wind
- 60.0 mph
Counties Boone County, IA, Greene County, IA, Hamilton County, IA, Webster County, IA
The radar
The Des Moines radar (KDMX), 57 km from the middle of the area, began a volume at 17:31 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 9, 12:43 PM CDT | HAIL 1 | Boxholm, IA | REPORT FROM MPING. |
| Jul 9, 12:50 PM CDT | HAIL 1 | 2 Wsw Pilot Mound, IA | |
| Jul 9, 1:02 PM CDT | HAIL 1.75 | Ogden, IA | CORRECTS PREVIOUS HAIL REPORT FROM OGDEN. |
| Jul 9, 1:05 PM CDT | HAIL 1.75 | Ogden, IA | LASTED ABOUT 2 MIN. |
| Jul 9, 1:14 PM CDT | HAIL 1.75 | 4 E Berkley, IA | |
| Jul 9, 1:15 PM CDT | HAIL 0.88 | 2 N Boone, IA |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 5.5 hours before the alert went out and 214 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
- 428 J/kg
- Mixed-layer CIN
- -350 J/kg
- Mixed-layer LCL
- 881 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km storm-relative helicity
- 404 m²/s²
- 0-3 km storm-relative helicity
- 551 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.9
The text
As transmitted.
854
WUUS53 KDMX 091728
SVRDMX
IAC015-073-079-187-091815-
/O.NEW.KDMX.SV.W.0058.210709T1728Z-210709T1815Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
1228 PM CDT Fri Jul 9 2021
The National Weather Service in Des Moines has issued a
* Severe Thunderstorm Warning for...
Northeastern Greene County in west central Iowa...
Southeastern Webster County in central Iowa...
Northwestern Boone County in central Iowa...
Southwestern Hamilton County in central Iowa...
* Until 115 PM CDT.
* At 1228 PM CDT, a severe thunderstorm was located 7 miles southeast
of Gowrie, or 18 miles northeast of Jefferson, moving southeast at
30 mph.
HAZARD...60 mph wind gusts and half dollar size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* Locations impacted include...
Ogden, Boone and Boone Speedway.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4223 9439 4240 9418 4217 9370 4215 9370
4190 9402
TIME...MOT...LOC 1728Z 307DEG 28KT 4223 9416
HAIL...1.25IN
WIND...60MPH
$$
Fowle3 follow-up statements
953
WWUS53 KDMX 091745
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
1245 PM CDT Fri Jul 9 2021
IAC015-073-079-187-091815-
/O.CON.KDMX.SV.W.0058.000000T0000Z-210709T1815Z/
Greene IA-Webster IA-Boone IA-Hamilton IA-
1245 PM CDT Fri Jul 9 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 PM CDT
FOR NORTHEASTERN GREENE...SOUTHEASTERN WEBSTER...NORTHWESTERN BOONE
AND SOUTHWESTERN HAMILTON COUNTIES...
At 1244 PM CDT, a severe thunderstorm was located 8 miles north of
Ogden, or 12 miles northwest of Boone, moving southeast at 25 mph.
HAZARD...Ping pong ball size hail and 60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...People and animals outdoors will be injured. Expect hail
damage to roofs, siding, windows, and vehicles. Expect wind
damage to roofs, siding, and trees.
Locations impacted include...
Boone, Ogden, Boone Speedway, Dayton, Stratford, Harcourt, Paton,
Boxholm, Pilot Mound, Fraser, Dana, Beaver, Boone Municipal Airport
and Ledges State Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.
To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Des Moines .
&&
LAT...LON 4218 9434 4234 9409 4217 9370 4215 9370
4190 9402
TIME...MOT...LOC 1744Z 315DEG 22KT 4215 9408
HAIL...1.50IN
WIND...60MPH
$$
Fowle578
WWUS53 KDMX 091757
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
1257 PM CDT Fri Jul 9 2021
IAC079-091805-
/O.CAN.KDMX.SV.W.0058.000000T0000Z-210709T1815Z/
Hamilton IA-
1257 PM CDT Fri Jul 9 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN HAMILTON COUNTY
IS CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled.
LAT...LON 4212 9427 4221 9406 4217 9370 4215 9370
4190 9402
TIME...MOT...LOC 1755Z 318DEG 27KT 4206 9405
$$
IAC015-073-187-091815-
/O.CON.KDMX.SV.W.0058.000000T0000Z-210709T1815Z/
Greene IA-Webster IA-Boone IA-
1257 PM CDT Fri Jul 9 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 PM CDT
FOR EAST CENTRAL GREENE...SOUTHEASTERN WEBSTER AND CENTRAL BOONE
COUNTIES...
At 1255 PM CDT, a severe thunderstorm was located over Ogden, or 8
miles west of Boone, moving southeast at 30 mph.
HAZARD...Golf ball size hail and 60 mph wind gusts.
SOURCE...Radar indicated. Several reports of quarter sized hail have
been reported and the storm appears to be strengthening.
IMPACT...People and animals outdoors will be injured. Expect hail
damage to roofs, siding, windows, and vehicles. Expect wind
damage to roofs, siding, and trees.
Locations impacted include...
Boone, Ogden, Boone Speedway, Boxholm, Pilot Mound, Fraser, Dana,
Beaver, Boone Municipal Airport and Ledges State Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This is a dangerous storm. Prepare immediately for large destructive
hail capable of producing significant damage. People outside should
move to a shelter, inside a strong building and away from windows.
&&
LAT...LON 4212 9427 4221 9406 4217 9370 4215 9370
4190 9402
TIME...MOT...LOC 1755Z 318DEG 27KT 4206 9405
HAIL...1.75IN
WIND...60MPH
$$
Fowle172
WWUS53 KDMX 091806
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
106 PM CDT Fri Jul 9 2021
IAC187-091816-
/O.CAN.KDMX.SV.W.0058.000000T0000Z-210709T1815Z/
Webster IA-
106 PM CDT Fri Jul 9 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WEBSTER COUNTY IS
CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled.
LAT...LON 4205 9419 4219 9401 4211 9375 4209 9378
4208 9379 4190 9402
TIME...MOT...LOC 1806Z 307DEG 28KT 4201 9396
$$
IAC015-073-091815-
/O.CON.KDMX.SV.W.0058.000000T0000Z-210709T1815Z/
Greene IA-Boone IA-
106 PM CDT Fri Jul 9 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 PM CDT
FOR EASTERN GREENE AND CENTRAL BOONE COUNTIES...
At 106 PM CDT, a severe thunderstorm was located near Ogden, or near
Boone, moving southeast at 30 mph.
HAZARD...Tennis ball size hail and 60 mph wind gusts.
SOURCE...Radar indicated. Trained spotters reported golf ball sized
hail and even larger hail is possible.
IMPACT...People and animals outdoors will be injured. Expect hail
damage to roofs, siding, windows, and vehicles. Expect wind
damage to roofs, siding, and trees.
Locations impacted include...
Boone, Ogden, Boone Speedway, Pilot Mound, Fraser, Beaver, Boone
Municipal Airport and Ledges State Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This is a dangerous storm. Prepare immediately for large destructive
hail capable of producing significant damage. People outside should
move to a shelter, inside a strong building and away from windows.
&&
LAT...LON 4205 9419 4219 9401 4211 9375 4209 9378
4208 9379 4190 9402
TIME...MOT...LOC 1806Z 307DEG 28KT 4201 9396
HAIL...2.50IN
WIND...60MPH
$$
FowleThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 9, 2:59 AM CDT | Flood Watch | DMX | Appanoose, Davis, Monroe, Wapello, Wayne | 13 min |
| Jul 9, 3:12 AM CDT | Flash Flood Watch | DMX | Appanoose, Clarke, Davis, Decatur, Lucas, Madison and 4 more | 30 hr |
| Jul 9, 8:09 AM CDT | Severe Thunderstorm Warning | DMX | Adair, Adams, Union | 28 min |
| Jul 9, 9:24 AM CDT | Special Weather Statement | DMX | Wayne | 21 min |
| Jul 9, 12:04 PM CDT | Special Weather Statement | DMX | Webster | 26 min |
| Jul 9, 1:01 PM CDT | Severe Thunderstorm Warning | DMX | Boone, Dallas, Greene, Polk, Story | 44 min |
| Jul 9, 1:27 PM CDT | Severe Thunderstorm Warning | DMX | Boone, Dallas, Madison, Polk, Story | 63 min |
| Jul 9, 2:06 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Madison, Marion, Polk, Warren | 54 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 2021Every severe thunderstorm warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.