Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 79, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Jul 14, 2021, 8:42 PM CDT for 4 counties in Iowa. It was in force for 43 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jul 14, 2021, 8:42 PM CDT (01:42 UTC)
- Expired
- Jul 14, 2021, 9:25 PM CDT
- In force
- 43 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Tornado
- Possible
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Jasper County, IA, Marshall County, IA, Polk County, IA, Story County, IA
The radar
The Des Moines radar (KDMX), 39 km from the middle of the area, began a volume at 01:41 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jul 14, 2:35 PM CDT | Tornado Watch | SPC | 8 hr |
The nearest sounding before it
Davenport, (KDVN), launched 00:00Z, 1.7 hours before the alert went out and 231 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
- 2569 J/kg
- Mixed-layer CIN
- -10 J/kg
- Mixed-layer LCL
- 832 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 253 m²/s²
- 0-3 km storm-relative helicity
- 346 m²/s²
- Significant tornado parameter
- 3.2
- Supercell composite
- 23.4
The text
As transmitted.
954 WUUS53 KDMX 150142 SVRDMX IAC099-127-153-169-150245- /O.NEW.KDMX.SV.W.0079.210715T0142Z-210715T0245Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Des Moines IA 842 PM CDT Wed Jul 14 2021 The National Weather Service in Des Moines has issued a * Severe Thunderstorm Warning for... Northeastern Polk County in central Iowa... Southern Story County in central Iowa... Marshall County in central Iowa... Northern Jasper County in central Iowa... * Until 945 PM CDT. * At 841 PM CDT, severe thunderstorms were located along a line extending from 10 miles south of Nevada to 6 miles south of Marshalltown, moving east at 40 mph. HAZARD...60 mph wind gusts and penny size hail. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. * Locations impacted include... Ames, Ankeny, Marshalltown, Newton, Altoona, Nevada, Bondurant, Huxley, Saylorville, Mitchellville, Colfax, State Center, Baxter, Rock Creek Lake, Adventureland Amusement Park, Prairie Meadows, Le Grand, Maxwell, Colo and Melbourne. This includes the following highways... Interstate 35 between mile markers 88 and 111. Interstate 80 between mile markers 141 and 163. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Tornado Watch remains in effect until 900 PM CDT for central Iowa. Remain alert for a possible tornado! Tornadoes can develop quickly from severe thunderstorms. If you spot a tornado go at once into the basement or small central room in a sturdy structure. For your protection move to an interior room on the lowest floor of a building. Torrential rainfall is occurring with these storms, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 4165 9358 4199 9364 4214 9277 4170 9277 TIME...MOT...LOC 0141Z 258DEG 35KT 4188 9339 4194 9293 TORNADO...POSSIBLE HAIL...0.75IN WIND...60MPH $$ Fowle
3 follow-up statements
875 WWUS53 KDMX 150153 SVSDMX Severe Weather Statement National Weather Service Des Moines IA 853 PM CDT Wed Jul 14 2021 IAC099-127-153-169-150245- /O.CON.KDMX.SV.W.0079.000000T0000Z-210715T0245Z/ Polk IA-Story IA-Marshall IA-Jasper IA- 853 PM CDT Wed Jul 14 2021 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM CDT FOR NORTHEASTERN POLK...SOUTHEASTERN STORY...SOUTHERN MARSHALL AND NORTHERN JASPER COUNTIES... At 853 PM CDT, severe thunderstorms were located along a line extending from near Bondurant to near Rock Creek Lake, moving east at 30 mph. HAZARD...60 mph wind gusts and penny size hail. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. Locations impacted include... Ankeny, Marshalltown, Newton, Altoona, Bondurant, Huxley, Saylorville, Mitchellville, Colfax, Baxter, Rock Creek Lake, Adventureland Amusement Park, Prairie Meadows, Le Grand, Maxwell, Melbourne, Cambridge, Elkhart, Kellogg and Gilman. This includes the following highways... Interstate 35 between mile markers 88 and 106. Interstate 80 between mile markers 141 and 163. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Tornado Watch remains in effect until 1100 PM CDT for central Iowa. Remain alert for a possible tornado! Tornadoes can develop quickly from severe thunderstorms. If you spot a tornado go at once into the basement or small central room in a sturdy structure. Torrential rainfall is occurring with these storms, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 4165 9358 4191 9362 4207 9277 4170 9277 TIME...MOT...LOC 0153Z 285DEG 26KT 4173 9339 4179 9294 TORNADO...POSSIBLE HAIL...0.75IN WIND...60MPH $$ Fowle
567 WWUS53 KDMX 150208 SVSDMX Severe Weather Statement National Weather Service Des Moines IA 908 PM CDT Wed Jul 14 2021 IAC099-127-153-169-150245- /O.CON.KDMX.SV.W.0079.000000T0000Z-210715T0245Z/ Polk IA-Story IA-Marshall IA-Jasper IA- 908 PM CDT Wed Jul 14 2021 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM CDT FOR NORTHEASTERN POLK...SOUTHEASTERN STORY...SOUTHERN MARSHALL AND NORTHERN JASPER COUNTIES... At 908 PM CDT, severe thunderstorms were located along a line extending from near Mitchellville to Rock Creek Lake, moving east at 35 mph. HAZARD...60 mph wind gusts and penny size hail. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. Locations impacted include... Ankeny, Newton, Altoona, Bondurant, Huxley, Saylorville, Mitchellville, Colfax, Baxter, Rock Creek Lake, Adventureland Amusement Park, Prairie Meadows, Maxwell, Melbourne, Cambridge, Elkhart, Kellogg, Gilman, Collins and Alleman. This includes the following highways... Interstate 35 between mile markers 88 and 104. Interstate 80 between mile markers 141 and 163. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Tornado Watch remains in effect until 1100 PM CDT for central Iowa. Intense thunderstorm lines can produce brief tornadoes and widespread significant wind damage. Although a tornado is not immediately likely, it is best to move to an interior room on the lowest floor of a building. These storms may cause serious injury and significant property damage. Torrential rainfall is occurring with these storms, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 4189 9362 4197 9277 4170 9277 4165 9358 TIME...MOT...LOC 0208Z 266DEG 29KT 4170 9331 4175 9281 HAIL...0.75IN WIND...60MPH $$ Fowle
888
WWUS53 KDMX 150225
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
925 PM CDT Wed Jul 14 2021
IAC099-127-153-169-150234-
/O.CAN.KDMX.SV.W.0079.000000T0000Z-210715T0245Z/
Polk IA-Story IA-Marshall IA-Jasper IA-
925 PM CDT Wed Jul 14 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN POLK...
SOUTHEASTERN STORY...SOUTHERN MARSHALL AND NORTHERN JASPER COUNTIES
IS CANCELLED...
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning has been cancelled. However gusty winds and
heavy rain are still possible with these thunderstorms.
A Tornado Watch remains in effect until 1100 PM CDT for central Iowa.
LAT...LON 4189 9362 4197 9277 4170 9277 4165 9358
TIME...MOT...LOC 0221Z 258DEG 35KT 4173 9313 4178 9263
$$
FowleThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 14, 7:03 PM CDT | Special Weather Statement | DMX | Story | 42 min |
| Jul 14, 7:23 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Marshall, Polk, Story | 67 min |
| Jul 14, 7:29 PM CDT | Severe Thunderstorm Warning | DMX | Tama | 14 min |
| Jul 14, 8:10 PM CDT | Tornado Warning | DMX | Marshall | 35 min |
| Jul 14, 8:28 PM CDT | Flash Flood Warning | DMX | Marshall, Polk, Story | 6 hr |
| Jul 14, 8:45 PM CDT | Severe Thunderstorm Warning | DMX | Poweshiek, Tama | 45 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.