Alert archive / Iowa / Severe Thunderstorm Warnings in 2011
Severe Thunderstorm Warning 45, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at Apr 9, 2011, 11:11 PM CDT for Buena Vista County, Clay County, Iowa. It was in force for 34 min. 1 report 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
- Apr 9, 2011, 11:11 PM CDT (04:11 UTC)
- Expired
- Apr 9, 2011, 11:45 PM CDT
- In force
- 34 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Hail
- 1.5 in
- Wind
- 58.0 mph
Counties Buena Vista County, IA, Clay County, IA
The radar
The Sioux Falls radar (KFSD), 145 km from the middle of the area, began a volume at 04:13 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 |
|---|---|---|---|
| Apr 9, 11:31 PM CDT | HAIL 1 | 3 Ssw Greenville, IA | COVERING APPROXIMATELY HALF OF THE GROUND |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Apr 9, 5:48 PM CDT | Tornado Watch | SPC | 7 hr |
| Apr 9, 11:01 PM CDT | Tornado Watch | SPC | 5 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 4.2 hours before the alert went out and 207 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
- 3327 J/kg
- Mixed-layer CIN
- -24 J/kg
- Mixed-layer LCL
- 1533 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 270 m²/s²
- 0-3 km storm-relative helicity
- 403 m²/s²
- Significant tornado parameter
- 3.7
- Supercell composite
- 19.0
The text
As transmitted, in the capitals the NWS used until 2016.
712 WUUS53 KFSD 100411 SVRFSD IAC021-041-100445- /O.NEW.KFSD.SV.W.0045.110410T0411Z-110410T0445Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE SIOUX FALLS SD 1111 PM CDT SAT APR 9 2011 THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... NORTHERN BUENA VISTA COUNTY IN NORTHWEST IOWA... SOUTHERN CLAY COUNTY IN NORTHWEST IOWA... * UNTIL 1145 PM CDT * AT 1111 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING WALNUT SIZE HAIL. THIS STORM WAS LOCATED NEAR PETERSON...OR 18 MILES NORTHWEST OF STORM LAKE...AND MOVING NORTHEAST AT 45 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... SIOUX RAPIDS AROUND 1120 PM CDT... GREENVILLE AND MARATHON AROUND 1130 PM CDT... WEBB AROUND 1135 PM CDT... OTHER LOCATIONS IMPACTED BY THIS SEVERE THUNDERSTORM INCLUDE ROSSIE AND GILLETT GROVE. PRECAUTIONARY/PREPAREDNESS ACTIONS... SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD. && A TORNADO WATCH REMAINS IN EFFECT UNTIL 100 AM CDT SUNDAY MORNING FOR NORTHWEST IOWA AND SOUTHWEST MINNESOTA AND NORTHEAST NEBRASKA AND SOUTHEASTERN SOUTH DAKOTA. A TORNADO WATCH ALSO REMAINS IN EFFECT UNTIL 500 AM CDT SUNDAY MORNING FOR NORTHWEST IOWA. LAT...LON 4308 9503 4286 9497 4280 9539 4295 9541 TIME...MOT...LOC 0411Z 230DEG 37KT 4288 9535 WIND...HAIL <58MPH 1.50IN $$
1 follow-up statement
160 WWUS53 KFSD 100420 SVSFSD SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 1120 PM CDT SAT APR 9 2011 IAC021-041-100445- /O.CON.KFSD.SV.W.0045.000000T0000Z-110410T0445Z/ CLAY IA-BUENA VISTA IA- 1120 PM CDT SAT APR 9 2011 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN BUENA VISTA AND SOUTHERN CLAY COUNTIES UNTIL 1145 PM CDT... AT 1120 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING WALNUT SIZE HAIL. THIS STORM WAS LOCATED NEAR LINN GROVE...OR 17 MILES SOUTHWEST OF SPENCER...MOVING NORTHEAST AT 45 MPH. THE SEVERE THUNDERSTORM WILL BE NEAR... GREENVILLE AND MARATHON AROUND 1130 PM CDT... WEBB AROUND 1135 PM CDT... OTHER LOCATIONS IMPACTED BY THIS SEVERE THUNDERSTORM INCLUDE ROSSIE AND GILLETT GROVE. PRECAUTIONARY/PREPAREDNESS ACTIONS... A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH NOT IMMEDIATELY LIKELY...IF A TORNADO IS SPOTTED ACT QUICKLY AND MOVE TO A PLACE OF SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM. SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD. && LAT...LON 4282 9532 4296 9537 4308 9503 4286 9497 TIME...MOT...LOC 0420Z 230DEG 37KT 4294 9525 WIND...HAIL <58MPH 1.50IN $$ CJ
The office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 7:09 PM CDT | Severe Thunderstorm Warning | FSD | Ida, Woodbury | 36 min |
| Apr 9, 7:31 PM CDT | Tornado Warning | FSD | Ida | 29 min |
| Apr 9, 7:44 PM CDT | Severe Thunderstorm Warning | FSD | Ida | 31 min |
| Apr 9, 7:46 PM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Ida, Woodbury | 29 min |
| Apr 9, 7:56 PM CDT | Tornado Warning | FSD | Ida | 34 min |
| Apr 9, 8:08 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee, Ida, Woodbury | 37 min |
| Apr 9, 8:11 PM CDT | Severe Thunderstorm Warning | FSD | Ida | 34 min |
| Apr 9, 8:19 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth, Woodbury | 41 min |
| Apr 9, 8:40 PM CDT | Severe Thunderstorm Warning | FSD | Cherokee | 35 min |
| Apr 9, 8:41 PM CDT | Severe Thunderstorm Warning | FSD | Ida | 19 min |
| Apr 9, 8:49 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista | 41 min |
| Apr 9, 8:55 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth, Woodbury | 35 min |
| Apr 9, 9:08 PM CDT | Severe Thunderstorm Warning | FSD | Cherokee | 37 min |
| Apr 9, 9:09 PM CDT | Tornado Warning | FSD | Buena Vista | 36 min |
| Apr 9, 9:15 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth, Sioux | 30 min |
| Apr 9, 9:17 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth, Woodbury | 43 min |
| Apr 9, 9:24 PM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Plymouth, Woodbury | 36 min |
| Apr 9, 9:25 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista | 20 min |
| Apr 9, 9:31 PM CDT | Tornado Warning | FSD | Plymouth, Woodbury | 29 min |
| Apr 9, 9:36 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee, Clay | 39 min |
| Apr 9, 9:46 PM CDT | Tornado Warning | FSD | Buena Vista | 29 min |
| Apr 9, 9:48 PM CDT | Tornado Warning | FSD | Cherokee | 27 min |
| Apr 9, 9:58 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth | 32 min |
| Apr 9, 10:02 PM CDT | Tornado Warning | FSD | Buena Vista | 28 min |
| Apr 9, 10:09 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista | 36 min |
| Apr 9, 10:13 PM CDT | Tornado Warning | FSD | Buena Vista, Cherokee | 47 min |
| Apr 9, 10:24 PM CDT | Severe Thunderstorm Warning | FSD | Cherokee, O'Brien, Plymouth, Sioux | 36 min |
| Apr 9, 10:31 PM CDT | Tornado Warning | FSD | Cherokee | 29 min |
| Apr 9, 10:35 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Clay | 30 min |
| Apr 9, 10:50 PM CDT | Tornado Warning | FSD | Buena Vista, Cherokee | 40 min |
| Apr 9, 11:27 PM CDT | Tornado Warning | FSD | Buena Vista, Clay | 18 min |
| Apr 9, 11:39 PM CDT | Tornado Warning | FSD | Clay | 21 min |
| Apr 10, 12:24 AM CDT | Severe Thunderstorm Warning | FSD | Woodbury | 36 min |
| Apr 10, 12:47 AM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Ida | 28 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 2011Every severe thunderstorm warning in 2011
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.