Alert archive / North Dakota / Tornado Warnings in 2017

Tornado Warning 6, NWS Bismarck, ND

August 12, 2017Sioux County, North Dakota

NWS Bismarck, ND issued this tornado warning at Aug 12, 2017, 6:53 PM CDT for Sioux County, North Dakota. It was in force for 37 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
Aug 12, 2017, 6:53 PM CDT (23:53 UTC)
Expired
Aug 12, 2017, 7:30 PM CDT
In force
37 min
Issued by
NWS Bismarck, ND
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.5 in

County Sioux County, ND

The radar

The Bismarck radar (KBIS), 88 km from the middle of the area, began a volume at 23:55 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 nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 11.9 hours before the alert went out and 90 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-pSkew-T log-p diagram, Bismarck Municip, ND at 12:00Z on 2017-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 108 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Bismarck Municip, ND at 12:00Z on 2017-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 142 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
108 J/kg
Mixed-layer CIN
-88 J/kg
Mixed-layer LCL
932 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
142 m²/s²
0-3 km storm-relative helicity
225 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

490 
WFUS53 KBIS 122353
TORBIS
NDC085-130030-
/O.NEW.KBIS.TO.W.0006.170812T2353Z-170813T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Bismarck ND
653 PM CDT SAT AUG 12 2017

The National Weather Service in Bismarck has issued a

* Tornado Warning for...
  South central Sioux County in south central North Dakota...

* Until 730 PM CDT
    
* At 653 PM CDT, a severe thunderstorm capable of producing a tornado
  was located 10 miles southwest of Shields, or 14 miles west of
  Selfridge, moving southeast at 15 mph.

  HAZARD...Tornado and ping pong 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 tornadic thunderstorm will remain over mainly rural areas of
  south central Sioux County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This Tornado Warning replaces the Severe Thunderstorm Warning issued
for the same area.

&&

LAT...LON 4609 10131 4614 10122 4608 10101 4595 10103
      4594 10116 4594 10118
TIME...MOT...LOC 2353Z 317DEG 15KT 4609 10122 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

SIMOSKO
3 follow-up statements
619 
WWUS53 KBIS 130006
SVSBIS

Severe Weather Statement
National Weather Service Bismarck ND
706 PM CDT SAT AUG 12 2017

NDC085-130030-
/O.CON.KBIS.TO.W.0006.000000T0000Z-170813T0030Z/
Sioux ND-
706 PM CDT SAT AUG 12 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 730 PM CDT FOR SOUTH
CENTRAL SIOUX COUNTY...
    
At 705 PM CDT, a severe thunderstorm capable of producing a tornado
was located 10 miles north of Walker, or 11 miles west of Selfridge,
moving southeast at 15 mph.

HAZARD...Tornado and ping pong 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 tornadic thunderstorm will remain over mainly rural areas of
south central Sioux County.

LAT...LON 4605 10128 4612 10115 4608 10101 4595 10103
      4594 10116 4594 10118
TIME...MOT...LOC 0005Z 317DEG 15KT 4605 10117 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

SIMOSKO
683 
WWUS53 KBIS 130022
SVSBIS

Severe Weather Statement
National Weather Service Bismarck ND
722 PM CDT SAT AUG 12 2017

NDC085-130030-
/O.CON.KBIS.TO.W.0006.000000T0000Z-170813T0030Z/
Sioux ND-
722 PM CDT SAT AUG 12 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 730 PM CDT FOR SOUTH
CENTRAL SIOUX COUNTY...
    
At 722 PM CDT, a severe thunderstorm capable of producing a tornado
was located 5 miles north of Walker, or 8 miles west of Selfridge,
moving southeast at 15 mph.

HAZARD...Tornado and ping pong 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 tornadic thunderstorm will remain over mainly rural areas of
south central Sioux County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4603 10126 4607 10107 4608 10101 4595 10103
      4594 10116 4594 10118
TIME...MOT...LOC 0022Z 317DEG 15KT 4600 10110 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

SIMOSKO
434 
WWUS53 KBIS 130028
SVSBIS

Severe Weather Statement
National Weather Service Bismarck ND
728 PM CDT SAT AUG 12 2017

NDC085-130038-
/O.EXP.KBIS.TO.W.0006.000000T0000Z-170813T0030Z/
Sioux ND-
728 PM CDT SAT AUG 12 2017

...THE TORNADO WARNING FOR SOUTH CENTRAL SIOUX COUNTY WILL EXPIRE AT
730 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However small hail
and heavy rain are still possible with this thunderstorm.

LAT...LON 4603 10126 4607 10107 4608 10101 4595 10103
      4594 10116 4594 10118
TIME...MOT...LOC 0028Z 317DEG 15KT 4598 10108 

$$

SIMOSKO

The office that day

Everything else NWS Bismarck, ND issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 11, 7:44 PM CDTSpecial Weather StatementBISGolden Valley46 min
Aug 11, 8:06 PM CDTSevere Thunderstorm WarningBISGolden Valley, McKenzie54 min
Aug 11, 8:57 PM CDTSevere Thunderstorm WarningBISGolden Valley63 min
Aug 11, 9:54 PM CDTSevere Thunderstorm WarningBISBillings, Golden Valley66 min
Aug 11, 10:57 PM CDTSevere Thunderstorm WarningBISBillings, Golden Valley, Slope, Stark63 min
Aug 12, 2:03 PM CDTSpecial Weather StatementBISMcIntosh42 min
Aug 12, 2:13 PM CDTSevere Thunderstorm WarningBISMcIntosh62 min
Aug 12, 3:15 PM CDTSpecial Weather StatementBISStark45 min
Aug 12, 3:22 PM CDTSpecial Weather StatementBISDickey38 min
Aug 12, 3:33 PM CDTSpecial Weather StatementBISBowman42 min
Aug 12, 3:39 PM CDTSevere Thunderstorm WarningBISBowman31 min
Aug 12, 3:56 PM CDTSpecial Weather StatementBISDickey49 min
Aug 12, 4:00 PM CDTSpecial Weather StatementBISMercer45 min
Aug 12, 4:09 PM CDTSpecial Weather StatementBISBillings51 min
Aug 12, 4:27 PM CDTSpecial Weather StatementBISMercer48 min
Aug 12, 4:34 PM CDTSevere Thunderstorm WarningBISMercer56 min
Aug 12, 4:45 PM CDTSpecial Weather StatementBISBillings45 min
Aug 12, 4:51 PM CDTSpecial Weather StatementBISMercer39 min
Aug 12, 5:14 PM CDTSevere Thunderstorm WarningBISHettinger, Slope, Stark61 min
Aug 12, 5:36 PM CDTSevere Thunderstorm WarningBISGrant, Morton54 min
Aug 12, 6:17 PM CDTSevere Thunderstorm WarningBISAdams, Hettinger58 min
Aug 12, 6:25 PM CDTSevere Thunderstorm WarningBISGrant, Sioux65 min

Nearby

Tornado Warnings in North Dakota, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.