Alert archive / Minnesota / Tornado Warnings in 2017

Tornado Warning 30, NWS Sioux Falls, SD

August 18, 2017Nobles County, Minnesota

NWS Sioux Falls, SD issued this tornado warning at Aug 18, 2017, 7:18 PM CDT for Nobles County, Minnesota. It was in force for 27 min. 5 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: Aug 18, 2017, 7:18 PM CDT (00:18 UTC)
Expired: Aug 18, 2017, 7:45 PM CDT
In force: 27 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.75 in

County Nobles County, MN

The radar

The Sioux Falls radar (KFSD), 73 km from the middle of the area, began a volume at 00:16 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
Aug 18, 7:20 PM CDT	HAIL 1.5	2 S Wilmont, MN
Aug 18, 7:26 PM CDT	TORNADO	3 Nw Rushmore, MN	EF1 TORNADO TRAVELED 1.6 MILES WITH A 50 YARD WIDE PATH. THE TORNADO LIFTED AT 7:35 JUST SOUTHWEST OF RUSHMORE.
Aug 18, 7:26 PM CDT	TORNADO	3 Nw Rushmore, MN	TORNADO TRAVELED 1.6 MILES WITH A 50 YARD WIDE PATH. THE TORNADO LIFTED AT 7:35 JUST SOUTHWEST OF RUSHMORE.
Aug 18, 7:37 PM CDT	TORNADO	1 Wnw Rushmore, MN	EF 1 TORNADO TRACKED FROM 1 WNW OF RUSHMORE TO 1 SW OF RUSHMORE. TORNADO LIFTED AT 7:43 PM. PATH LENGTH WAS 1.25 MILES WITH MAXIMUM WIDTH OF 75 TO 100 YARDS. PEAK WINDS ESTIMATED AT 91 MPH WITH DAMAGE CONFINED TO FIELD CROPS.
Aug 18, 7:37 PM CDT	TORNADO	1 Wnw Rushmore, MN	TORNADO TRACKED FROM 1 WNW OF RUSHMORE TO 1 SW OF RUSHMORE. TORNADO LIFTED AT 7:43 PM. PATH LENGTH WAS 1.25 MILES WITH MAXIMUM WIDTH OF 75 TO 100 YARDS. PEAK WINDS ESTIMATED AT 91 MPH WITH DAMAGE CONFINED TO FIELD CROPS.

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
Aug 18, 4:51 PM CDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 0.3 hours before the alert went out and 220 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 13 J/kg
Mixed-layer CIN: -140 J/kg
Mixed-layer LCL: 1494 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 14 m²/s²
0-3 km storm-relative helicity: 53 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

048 
WFUS53 KFSD 190018
TORFSD
MNC105-190045-
/O.NEW.KFSD.TO.W.0030.170819T0018Z-170819T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sioux Falls SD
718 PM CDT FRI AUG 18 2017

The National Weather Service in Sioux Falls has issued a

* Tornado Warning for...
  Central Nobles County in southwestern Minnesota...

* Until 745 PM CDT
    
* At 718 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Wilmont, or 15 miles northwest of Worthington,
  moving southeast at 20 mph.

  HAZARD...Tornado and golf ball size hail. 

  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...
  Rushmore around 745 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.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4375 9593 4379 9582 4360 9565 4356 9583
TIME...MOT...LOC 0018Z 334DEG 17KT 4374 9588 

TORNADO...RADAR INDICATED
HAIL...1.75IN

$$

Ferguson

2 follow-up statements

099 
WWUS53 KFSD 190025
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
725 PM CDT FRI AUG 18 2017

MNC105-190045-
/O.CON.KFSD.TO.W.0030.000000T0000Z-170819T0045Z/
Nobles MN-
725 PM CDT FRI AUG 18 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR CENTRAL
NOBLES COUNTY...
    
At 725 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Rushmore, or 12 miles west of Worthington, moving
southeast at 20 mph.

HAZARD...Tornado and golf ball size hail. 

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...
  Rushmore around 735 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.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4372 9591 4375 9579 4360 9565 4356 9583
TIME...MOT...LOC 0025Z 332DEG 17KT 4367 9583 

TORNADO...RADAR INDICATED
HAIL...1.75IN

$$

Ferguson

323 
WWUS53 KFSD 190046
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
746 PM CDT FRI AUG 18 2017

MNC105-190056-
/O.EXP.KFSD.TO.W.0030.000000T0000Z-170819T0045Z/
Nobles MN-
746 PM CDT FRI AUG 18 2017

...THE TORNADO WARNING FOR CENTRAL NOBLES COUNTY HAS EXPIRED...
    
The tornado threat has diminished and the Tornado Warning has been
cancelled. However, large hail and damaging winds remain likely and a
Severe Thunderstorm Warning remains in effect for the area.

A severe thunderstorm watch remains in effect until 100 AM CDT for
southwestern Minnesota.

LAT...LON 4372 9591 4375 9579 4360 9565 4356 9583
TIME...MOT...LOC 0046Z 334DEG 17KT 4358 9577 

$$

Ferguson

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 18, 7:11 PM CDT	Severe Thunderstorm Warning	FSD	Nobles	34 min
Aug 18, 7:15 PM CDT	Severe Thunderstorm Warning	FSD	Cottonwood, Jackson	30 min
Aug 18, 7:45 PM CDT	Severe Thunderstorm Warning	FSD	Nobles	30 min
Aug 18, 7:49 PM CDT	Tornado Warning	FSD	Nobles	26 min

Nearby

Tornado Warnings in Minnesota, 2017 Every tornado warning in 2017 Tornadoes 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.