Alert archive / Iowa / Severe Thunderstorm Warnings in 2012
Severe Thunderstorm Warning 24, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at May 1, 2012, 8:09 PM CDT for Lyon County, Iowa. It was in force for 36 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
- May 1, 2012, 8:09 PM CDT (01:09 UTC)
- Expired
- May 1, 2012, 8:45 PM CDT
- In force
- 36 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Hail
- 1.75 in
- Wind
- 58.0 mph
County Lyon County, IA
The radar
The Sioux Falls radar (KFSD), 59 km from the middle of the area, began a volume at 01:12 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 |
|---|---|---|---|
| May 1, 2:59 PM CDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 1.2 hours before the alert went out and 228 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
- 1502 J/kg
- Mixed-layer CIN
- -30 J/kg
- Mixed-layer LCL
- 1477 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 75 m²/s²
- 0-3 km storm-relative helicity
- 122 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 5.2
The text
As transmitted, in the capitals the NWS used until 2016.
204 WUUS53 KFSD 020109 SVRFSD IAC119-020145- /O.NEW.KFSD.SV.W.0024.120502T0109Z-120502T0145Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE SIOUX FALLS SD 809 PM CDT TUE MAY 1 2012 THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... EASTERN LYON COUNTY IN NORTHWEST IOWA... * UNTIL 845 PM CDT * AT 810 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING GOLF BALL SIZE HAIL. THIS STORM WAS LOCATED NEAR DOON...OR 7 MILES SOUTH OF ROCK RAPIDS...AND MOVING NORTHEAST AT 30 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... ROCK RAPIDS AROUND 815 PM CDT... GEORGE AROUND 825 PM CDT... LITTLE ROCK AROUND 845 PM CDT... 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 1000 PM CDT TUESDAY EVENING FOR NORTHWEST IOWA AND SOUTHWEST MINNESOTA AND SOUTHEASTERN SOUTH DAKOTA. LAT...LON 4326 9620 4350 9622 4350 9587 4326 9587 TIME...MOT...LOC 0110Z 237DEG 25KT 4334 9617 WIND...HAIL <58MPH 1.75IN $$ CJ
2 follow-up statements
836 WWUS53 KFSD 020129 SVSFSD SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 829 PM CDT TUE MAY 1 2012 IAC119-020145- /O.CON.KFSD.SV.W.0024.000000T0000Z-120502T0145Z/ LYON IA- 829 PM CDT TUE MAY 1 2012 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR EASTERN LYON COUNTY UNTIL 845 PM CDT... AT 829 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING HALF DOLLAR SIZE HAIL. THIS STORM WAS LOCATED NEAR GEORGE...OR 6 MILES EAST OF ROCK RAPIDS...MOVING NORTHEAST AT 30 MPH. THE SEVERE THUNDERSTORM WILL BE NEAR... LITTLE ROCK AROUND 845 PM CDT... PRECAUTIONARY/PREPAREDNESS ACTIONS... A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH NOT IMMEDIATELY LIKELY...IF A TORNADO IS SPOTTED ACT QUICKLY AND MOVE TO A PLACE OF SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM. SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD. && LAT...LON 4326 9617 4350 9618 4350 9587 4326 9587 TIME...MOT...LOC 0129Z 237DEG 25KT 4341 9602 WIND...HAIL <58MPH 1.25IN $$ CJ
518 WWUS53 KFSD 020144 SVSFSD SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 844 PM CDT TUE MAY 1 2012 IAC119-020154- /O.EXP.KFSD.SV.W.0024.000000T0000Z-120502T0145Z/ LYON IA- 844 PM CDT TUE MAY 1 2012 ...THE SEVERE THUNDERSTORM WARNING FOR EASTERN LYON COUNTY WILL EXPIRE AT 845 PM CDT... THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY...HOWEVER SMALL HAIL AND HEAVY RAIN ARE STILL POSSIBLE WITH THIS THUNDERSTORM. LAT...LON 4326 9617 4350 9618 4350 9587 4326 9587 TIME...MOT...LOC 0144Z 237DEG 25KT 4347 9590 $$ CJ
The office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 1, 7:12 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 33 min |
| May 1, 7:27 PM CDT | Tornado Warning | FSD | Lyon, Sioux | 33 min |
| May 1, 7:41 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 34 min |
| May 1, 7:57 PM CDT | Tornado Warning | FSD | Lyon | 33 min |
| May 1, 8:40 PM CDT | Flash Flood Warning | FSD | Lyon | 3 hr |
| May 1, 9:15 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee, Clay, O'Brien, Plymouth, Sioux | 30 min |
| May 1, 9:22 PM CDT | Severe Thunderstorm Warning | FSD | Dickinson, Osceola | 38 min |
| May 1, 9:29 PM CDT | Tornado Warning | FSD | Clay, O'Brien | 46 min |
| May 1, 9:41 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee, Clay, Dickinson, O'Brien, Osceola | 34 min |
| May 1, 9:44 PM CDT | Tornado Warning | FSD | Clay | 31 min |
| May 1, 10:13 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Clay, Dickinson | 17 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 2012Every severe thunderstorm warning in 2012
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.