Alert archive / North Dakota / Tornado Warnings in 2017

Tornado Warning 37, NWS Grand Forks, ND

September 1, 2017Nelson County, North Dakota

NWS Grand Forks, ND issued this tornado warning at Sep 1, 2017, 5:40 PM CDT for Nelson County, North Dakota. It was in force for 35 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: Sep 1, 2017, 5:40 PM CDT (22:40 UTC)
Expired: Sep 1, 2017, 6:15 PM CDT
In force: 35 min
Issued by: NWS Grand Forks, ND
Area: Storm-based polygon
Tornado: Observed
Hail: 1.0 in

County Nelson County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 72 km from the middle of the area, began a volume at 22:41 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
Sep 1, 5:59 PM CDT	HAIL 1	5 Nnw Mcville, ND	HEAVY RAIN WITH A FEW DIME TO QUARTER SIZED HAIL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 10.7 hours before the alert went out and 236 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: 143 J/kg
Mixed-layer CIN: -272 J/kg
Mixed-layer LCL: 1132 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 224 m²/s²
0-3 km storm-relative helicity: 281 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

240 
WFUS53 KFGF 012240
TORFGF
NDC063-012315-
/O.NEW.KFGF.TO.W.0037.170901T2240Z-170901T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Eastern ND/Grand Forks ND
540 PM CDT FRI SEP 1 2017

The National Weather Service in Grand Forks has issued a

* Tornado Warning for...
  East central Nelson County in northeastern North Dakota...

* Until 615 PM CDT.

* At 540 PM CDT, a confirmed tornado was located 7 miles northeast of
  Pekin, or 33 miles southeast of Devils Lake, moving east at 20 mph.

  HAZARD...Tornado and quarter size hail. 

  SOURCE...Public confirmed tornado. 

  IMPACT...Expect damage to mobile homes, roofs, and vehicles. 

* Locations impacted include...
  Petersburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Grand Forks.

&&

LAT...LON 4792 9832 4805 9790 4802 9790 4802 9789
      4778 9789 4781 9831
TIME...MOT...LOC 2240Z 256DEG 19KT 4789 9823 

TORNADO...OBSERVED
HAIL...1.00IN

$$

Lee

1 follow-up statement

991 
WWUS53 KFGF 012256
SVSFGF

Severe Weather Statement
National Weather Service Eastern ND/Grand Forks ND
556 PM CDT FRI SEP 1 2017

NDC063-012315-
/O.CON.KFGF.TO.W.0037.000000T0000Z-170901T2315Z/
Nelson ND-
556 PM CDT FRI SEP 1 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR EAST
CENTRAL NELSON COUNTY...
    
At 555 PM CDT, a confirmed tornado was located 8 miles south of
Michigan, or 37 miles east of Devils Lake, moving east at 30 mph.

HAZARD...TORNADO. 

SOURCE...Weather spotters confirmed tornado. At 545 pm, trained 
         weather spotters reported a rope tornado on the ground 
         approximately 10 miles southwest of Petersburg.

IMPACT...Expect damage to mobile homes, roofs, and vehicles. 

Locations impacted include...
Petersburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If a tornado or other severe weather is spotted, report it to the
National Weather Service or your local nearest law enforcement agency
who will send your report. This act may save lives of others in the
path of dangerous weather.

&&

LAT...LON 4792 9825 4805 9790 4802 9790 4802 9789
      4778 9789 4781 9826
TIME...MOT...LOC 2255Z 257DEG 24KT 4791 9813 

TORNADO...OBSERVED
HAIL...<.75IN

$$

Lee

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 1, 6:05 PM CDT	Special Weather Statement	FGF	Walsh	40 min
Sep 1, 6:12 PM CDT	Severe Thunderstorm Warning	FGF	Grand Forks, Nelson, Steele	33 min
Sep 1, 6:42 PM CDT	Special Weather Statement	FGF	Steele	48 min
Sep 1, 6:54 PM CDT	Severe Thunderstorm Warning	FGF	Griggs, Steele	51 min

Nearby

Tornado Warnings in North Dakota, 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.