Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 3, NWS Great Falls, MT

June 4, 2021Fergus County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jun 4, 2021, 9:45 PM MDT for Fergus County, Montana. It was in force for 45 min. 3 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: Jun 4, 2021, 9:45 PM MDT (03:45 UTC)
Expired: Jun 4, 2021, 10:30 PM MDT
In force: 45 min
Issued by: NWS Great Falls, MT
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Fergus County, MT

The radar

The Billings radar (KBLX), 142 km from the middle of the area, began a volume at 03:47 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
Jun 4, 9:56 PM MDT	TSTM WND GST 47	6 Nne Forestgrove, MT	AWOS STATION K1NM NOVEMBER.
Jun 4, 10:00 PM MDT	HAIL 0.25	5 Ene Forestgrove, MT	0.50 INCH RAINFALL.
Jun 4, 10:08 PM MDT	TSTM WND GST 40	Grass Range, MT	ESTIMATED 40 MPH WIND GUSTS. NO HAIL.

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
Jun 4, 4:01 PM MDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 3.8 hours before the alert went out and 142 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: 460 J/kg
Mixed-layer CIN: -28 J/kg
Mixed-layer LCL: 2772 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: 121 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

As transmitted.

256 
WUUS55 KTFX 050345
SVRTFX
MTC027-050430-
/O.NEW.KTFX.SV.W.0003.210605T0345Z-210605T0430Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Great Falls MT
945 PM MDT Fri Jun 4 2021

The National Weather Service in Great Falls has issued a

* Severe Thunderstorm Warning for...
  Southeastern Fergus County in central Montana...

* Until 1030 PM MDT.

* At 944 PM MDT, two severe thunderstorms were located 11 to 15 
  miles east of Lewistown, moving east-northeast at 35 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Grass Range, Giltedge and Forestgrove. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

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

&&

LAT...LON 4687 10919 4711 10931 4731 10860 4730 10859
      4727 10860 4727 10872 4719 10871 4718 10874
      4710 10874 4710 10862 4708 10860 4695 10861
TIME...MOT...LOC 0344Z 253DEG 29KT 4704 10918 

HAIL...1.00IN
WIND...60MPH
 
$$

Kredensor

3 follow-up statements

878 
WWUS55 KTFX 050400
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
1000 PM MDT Fri Jun 4 2021

MTC027-050430-
/O.CON.KTFX.SV.W.0003.000000T0000Z-210605T0430Z/
Fergus MT-
1000 PM MDT Fri Jun 4 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM MDT
FOR SOUTHEASTERN FERGUS COUNTY...

At 959 PM MDT, a severe thunderstorm was located near Grass Range, or
24 miles west of Winnett, moving east at 35 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Grass Range.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

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

&&

LAT...LON 4690 10898 4710 10907 4720 10871 4719 10871
      4718 10874 4710 10874 4710 10862 4708 10860
      4695 10861 4691 10892
TIME...MOT...LOC 0359Z 254DEG 30KT 4702 10887 

HAIL...1.00IN
WIND...60MPH
 
$$

Kredensor

515 
WWUS55 KTFX 050413
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
1013 PM MDT Fri Jun 4 2021

MTC027-050430-
/O.CON.KTFX.SV.W.0003.000000T0000Z-210605T0430Z/
Fergus MT-
1013 PM MDT Fri Jun 4 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM MDT
FOR EAST CENTRAL FERGUS COUNTY...

At 1012 PM MDT, a severe thunderstorm was located near Grass Range,
or 18 miles west of Winnett, moving east at 35 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Grass Range.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

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

&&

LAT...LON 4694 10879 4712 10889 4717 10874 4710 10874
      4710 10862 4708 10860 4696 10861
TIME...MOT...LOC 0412Z 251DEG 29KT 4706 10873 

HAIL...1.00IN
WIND...60MPH
 
$$

Kredensor

819 
WWUS55 KTFX 050429
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
1029 PM MDT Fri Jun 4 2021

MTC027-050439-
/O.EXP.KTFX.SV.W.0003.000000T0000Z-210605T0430Z/
Fergus MT-
1029 PM MDT Fri Jun 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL FERGUS COUNTY
WILL EXPIRE AT 1030 PM MDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Great Falls.

LAT...LON 4694 10879 4712 10889 4717 10874 4710 10874
      4710 10862 4708 10860 4696 10861
TIME...MOT...LOC 0429Z 253DEG 29KT 4710 10854 

$$

Kredensor

The office that day

Everything else NWS Great Falls, MT issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 4, 7:41 PM MDT	Special Weather Statement	TFX	Blaine	34 min
Jun 4, 9:22 PM MDT	Special Weather Statement	TFX	Fergus	53 min
Jun 4, 9:30 PM MDT	Severe Thunderstorm Warning	TFX	Gallatin	33 min
Jun 4, 9:36 PM MDT	Special Weather Statement	TFX	Gallatin	24 min
Jun 4, 10:45 PM MDT	Special Weather Statement	TFX	Fergus	45 min
Jun 5, 1:18 PM MDT	Special Weather Statement	TFX	Madison	27 min
Jun 5, 5:08 PM MDT	Special Weather Statement	TFX	Judith Basin	37 min

Nearby

Severe Thunderstorm Warnings in Montana, 2021 Every severe thunderstorm warning in 2021

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.