Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 11, NWS Great Falls, MT

June 9, 2021Blaine County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jun 9, 2021, 9:30 PM MDT for Blaine County, Montana. It was in force for 45 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: Jun 9, 2021, 9:30 PM MDT (03:30 UTC)
Expired: Jun 9, 2021, 10:15 PM MDT
In force: 45 min
Issued by: NWS Great Falls, MT
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

County Blaine County, MT

The radar

The Glasgow radar (KGGW), 153 km from the middle of the area, began a volume at 03:33 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 9, 10:05 PM MDT	HAIL 1	Hays, MT	QUARTER SIZE HAIL REPORTED DURING THE SECOND SYSTEM TO PASS OVER HAYS, MT.

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 9, 6:42 PM MDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 3.5 hours before the alert went out and 157 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: 22 J/kg
Mixed-layer CIN: -195 J/kg
Mixed-layer LCL: 1287 m above ground
0-6 km bulk shear: 71 kt
0-1 km storm-relative helicity: 12 m²/s²
0-3 km storm-relative helicity: 408 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

207 
WUUS55 KTFX 100330
SVRTFX
MTC005-100415-
/O.NEW.KTFX.SV.W.0011.210610T0330Z-210610T0415Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Great Falls MT
930 PM MDT Wed Jun 9 2021

The National Weather Service in Great Falls has issued a

* Severe Thunderstorm Warning for...
  Southeastern Blaine County in north central Montana...

* Until 1015 PM MDT.

* At 930 PM MDT, a severe thunderstorm was located 12 miles west of
  Hays, or 17 miles west of Zortman, moving northeast at 30 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Hays and Lodge Pole. 

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 4798 10851 4799 10860 4792 10864 4792 10888
      4781 10890 4804 10903 4828 10842 4798 10843
TIME...MOT...LOC 0330Z 244DEG 27KT 4792 10890 

HAIL...1.25IN
WIND...60MPH
 
$$

Kredensor

2 follow-up statements

008 
WWUS55 KTFX 100343
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
943 PM MDT Wed Jun 9 2021

MTC005-100415-
/O.CON.KTFX.SV.W.0011.000000T0000Z-210610T0415Z/
Blaine MT-
943 PM MDT Wed Jun 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1015 PM MDT
FOR SOUTHEASTERN BLAINE COUNTY...

At 943 PM MDT, a severe thunderstorm was located near Hays, or 13
miles west of Zortman, moving northeast at 30 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...
Hays and Lodge Pole. 

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 4792 10886 4803 10898 4812 10882 4825 10851
      4818 10842 4801 10843 4798 10850 4798 10851
      4799 10860 4792 10864
TIME...MOT...LOC 0343Z 231DEG 24KT 4798 10880 

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

Kredensor

720 
WWUS55 KTFX 100406
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
1006 PM MDT Wed Jun 9 2021

MTC005-100415-
/O.CON.KTFX.SV.W.0011.000000T0000Z-210610T0415Z/
Blaine MT-
1006 PM MDT Wed Jun 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1015 PM MDT
FOR EAST CENTRAL BLAINE COUNTY...

At 1006 PM MDT, a severe thunderstorm was located 10 miles northeast
of Hays, or 13 miles north of Zortman, moving northeast at 30 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Lodge Pole.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

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 4798 10854 4809 10871 4819 10866 4825 10851
      4818 10842 4801 10843 4798 10850
TIME...MOT...LOC 0406Z 209DEG 25KT 4812 10854 

HAIL...1.75IN
WIND...60MPH
 
$$

Kredensor

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 9, 6:18 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	42 min
Jun 9, 6:55 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	35 min
Jun 9, 7:08 PM MDT	Special Weather Statement	TFX	Fergus	22 min
Jun 9, 7:19 PM MDT	Special Weather Statement	TFX	Teton	56 min
Jun 9, 7:26 PM MDT	Special Weather Statement	TFX	Fergus	34 min
Jun 9, 7:28 PM MDT	Special Weather Statement	TFX	Judith Basin	32 min
Jun 9, 7:36 PM MDT	Special Weather Statement	TFX	Fergus	24 min
Jun 9, 7:53 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau, Fergus	37 min
Jun 9, 7:57 PM MDT	Special Weather Statement	TFX	Hill	33 min
Jun 9, 8:04 PM MDT	Special Weather Statement	TFX	Judith Basin	26 min
Jun 9, 8:19 PM MDT	Special Weather Statement	TFX	Teton	26 min
Jun 9, 8:28 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau, Judith Basin	32 min
Jun 9, 8:31 PM MDT	Special Weather Statement	TFX	Chouteau	29 min
Jun 9, 8:42 PM MDT	Severe Thunderstorm Warning	TFX	Blaine, Fergus	33 min
Jun 9, 8:45 PM MDT	Special Weather Statement	TFX	Petroleum	30 min
Jun 9, 8:48 PM MDT	Special Weather Statement	TFX	Hill	27 min
Jun 9, 8:57 PM MDT	Special Weather Statement	TFX	Blaine	18 min
Jun 9, 9:04 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau, Hill	26 min
Jun 9, 9:09 PM MDT	Severe Thunderstorm Warning	TFX	Blaine, Fergus	21 min
Jun 9, 9:18 PM MDT	Special Weather Statement	TFX	Toole	42 min
Jun 9, 9:26 PM MDT	Special Weather Statement	TFX	Blaine	49 min
Jun 9, 9:37 PM MDT	Special Weather Statement	TFX	Blaine	23 min
Jun 9, 9:38 PM MDT	Special Weather Statement	TFX	Fergus	37 min
Jun 9, 9:38 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	40 min
Jun 9, 9:51 PM MDT	Special Weather Statement	TFX	Blaine	24 min
Jun 9, 10:17 PM MDT	Special Weather Statement	TFX	Blaine	28 min
Jun 9, 10:32 PM MDT	Special Weather Statement	TFX	Fergus	43 min
Jun 9, 10:48 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	42 min
Jun 9, 11:34 PM MDT	Special Weather Statement	TFX	Blaine, Fergus, Hill	116 min
Jun 10, 2:11 AM MDT	Special Weather Statement	TFX	Blaine	34 min
Jun 10, 2:53 PM MDT	Special Weather Statement	TFX	Fergus	37 min
Jun 10, 3:08 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	52 min
Jun 10, 3:53 PM MDT	Special Weather Statement	TFX	Fergus	37 min
Jun 10, 4:22 PM MDT	Special Weather Statement	TFX	Cascade	23 min
Jun 10, 4:56 PM MDT	Special Weather Statement	TFX	Cascade	34 min
Jun 10, 5:33 PM MDT	Special Weather Statement	TFX	Cascade	27 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.