Alert archive / Iowa / Tornado Warnings in 2017
Tornado Warning 9, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this tornado warning at May 17, 2017, 2:28 PM CDT for Lyon County, Sioux County, Iowa. It was in force for 32 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
- May 17, 2017, 2:28 PM CDT (19:28 UTC)
- Expired
- May 17, 2017, 3:00 PM CDT
- In force
- 32 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 0.75 in
Counties Lyon County, IA, Sioux County, IA
The radar
The Sioux Falls radar (KFSD), 74 km from the middle of the area, began a volume at 19:29 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 |
|---|---|---|---|
| May 17, 2:42 PM CDT | TORNADO | 1 W Matlock, IA |
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 |
|---|---|---|---|
| May 17, 12:08 PM CDT | Tornado Watch | SPC | 7 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 7.5 hours before the alert went out and 210 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
- 121 J/kg
- Mixed-layer CIN
- -156 J/kg
- Mixed-layer LCL
- 1106 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 119 m²/s²
- 0-3 km storm-relative helicity
- 132 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
490
WFUS53 KFSD 171928
TORFSD
IAC119-167-172000-
/O.NEW.KFSD.TO.W.0009.170517T1928Z-170517T2000Z/
BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sioux Falls SD
228 PM CDT WED MAY 17 2017
The National Weather Service in Sioux Falls has issued a
* Tornado Warning for...
Southeastern Lyon County in northwestern Iowa...
Northeastern Sioux County in northwestern Iowa...
* Until 300 PM CDT
* At 227 PM CDT, a severe thunderstorm capable of producing a
tornado was located over Boyden, or west of Sheldon, moving north
at 30 mph.
HAZARD...Tornado.
SOURCE...Radar indicated rotation.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely.
* This dangerous storm will be near...
Boyden through 235 PM CDT.
Matlock around 235 PM CDT.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.
&&
LAT...LON 4313 9588 4306 9612 4326 9623 4335 9590
TIME...MOT...LOC 1927Z 170DEG 24KT 4318 9597
TORNADO...RADAR INDICATED
HAIL...<.75IN
$$
Ferguson3 follow-up statements
878
WWUS53 KFSD 171945
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
245 PM CDT WED MAY 17 2017
IAC119-167-172000-
/O.CON.KFSD.TO.W.0009.000000T0000Z-170517T2000Z/
Lyon IA-Sioux IA-
245 PM CDT WED MAY 17 2017
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 300 PM CDT FOR
SOUTHEASTERN LYON AND NORTHEASTERN SIOUX COUNTIES...
At 245 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Matlock, or 7 miles northwest of Sheldon, moving
north at 15 mph.
HAZARD...Tornado.
SOURCE...Radar indicated rotation.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed. Damage
to roofs, windows, and vehicles will occur. Tree damage is
likely.
This tornadic thunderstorm will remain over mainly rural areas of
southeastern Lyon and northeastern Sioux Counties.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.
&&
LAT...LON 4313 9588 4308 9607 4328 9614 4335 9590
TIME...MOT...LOC 1945Z 179DEG 13KT 4324 9596
TORNADO...RADAR INDICATED
HAIL...<.75IN
$$
Ferguson486
WWUS53 KFSD 171948 CCA
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
248 PM CDT WED MAY 17 2017
IAC119-167-172000-
/O.COR.KFSD.TO.W.0009.000000T0000Z-170517T2000Z/
Lyon IA-Sioux IA-
248 PM CDT WED MAY 17 2017
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 300 PM CDT FOR
SOUTHEASTERN LYON AND NORTHEASTERN SIOUX COUNTIES...
At 248 PM CDT, a confirmed tornado was located over Matlock, or 7
miles northwest of Sheldon, moving north at 15 mph.
HAZARD...Damaging tornado.
SOURCE...Storm chaser confirmed tornado. At 242 PM CDT, a storm
chaser reported a tornado near Matlock.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed. Damage
to roofs, windows, and vehicles will occur. Tree damage is
likely.
Locations impacted include...
Boyden and Matlock.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.
&&
LAT...LON 4313 9588 4308 9607 4328 9614 4335 9590
TIME...MOT...LOC 1945Z 179DEG 13KT 4324 9596
TORNADO...OBSERVED
HAIL...<.75IN
$$
Ferguson893
WWUS53 KFSD 171955
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
255 PM CDT WED MAY 17 2017
IAC119-167-172005-
/O.EXP.KFSD.TO.W.0009.000000T0000Z-170517T2000Z/
Lyon IA-Sioux IA-
255 PM CDT WED MAY 17 2017
...THE TORNADO WARNING FOR SOUTHEASTERN LYON AND NORTHEASTERN SIOUX
COUNTIES WILL EXPIRE AT 300 PM CDT...
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore the warning will be allowed to expire. However small hail
and heavy rain are still possible with this thunderstorm.
A tornado watch remains in effect until 700 PM CDT for northwestern
Iowa.
LAT...LON 4313 9588 4308 9607 4328 9614 4335 9590
TIME...MOT...LOC 1955Z 179DEG 13KT 4327 9596
$$
FergusonThe office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 16, 7:43 PM CDT | Severe Thunderstorm Warning | FSD | Ida | 33 min |
| May 16, 8:22 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista | 23 min |
| May 17, 11:16 AM CDT | River Flood Warning | FSD | Clay | 24 hr |
| May 17, 11:16 AM CDT | River Flood Warning | FSD | Buena Vista, Clay | 24 hr |
| May 17, 11:16 AM CDT | River Flood Warning | FSD | Plymouth, Sioux | 5 days |
| May 17, 11:16 AM CDT | River Flood Warning | FSD | Plymouth | 6 days |
| May 17, 11:16 AM CDT | River Flood Warning | FSD | Clay | 4 days |
| May 17, 11:16 AM CDT | River Flood Warning | FSD | Clay, Dickinson | 59 hr |
| May 17, 1:33 PM CDT | Tornado Warning | FSD | Sioux | 27 min |
| May 17, 1:56 PM CDT | Tornado Warning | FSD | Sioux | 34 min |
| May 17, 2:03 PM CDT | Tornado Warning | FSD | Sioux | 27 min |
| May 17, 2:34 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 26 min |
| May 17, 3:01 PM CDT | Tornado Warning | FSD | Lyon | 29 min |
Nearby
Tornado Warnings in Iowa, 2017Every tornado warning in 2017Tornadoes in 2017
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.