Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 27, NWS Great Falls, MT

July 6, 2021Blaine County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 6, 2021, 6:50 PM MDT for Blaine County, Montana. It was in force for 40 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: Jul 6, 2021, 6:50 PM MDT (00:50 UTC)
Expired: Jul 6, 2021, 7:30 PM MDT
In force: 40 min
Issued by: NWS Great Falls, MT
Area: Storm-based polygon
Hail: 1.75 in
Wind: 60.0 mph

County Blaine County, MT

The radar

The Glasgow radar (KGGW), 145 km from the middle of the area, began a volume at 00:50 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

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 0.8 hours before the alert went out and 146 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: 20 J/kg
Mixed-layer CIN: -155 J/kg
Mixed-layer LCL: 1401 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: -5 m²/s²
0-3 km storm-relative helicity: 134 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

660 
WUUS55 KTFX 070050
SVRTFX
MTC005-070130-
/O.NEW.KTFX.SV.W.0027.210707T0050Z-210707T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Great Falls MT
650 PM MDT Tue Jul 6 2021

The National Weather Service in Great Falls has issued a

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

* Until 730 PM MDT.

* At 649 PM MDT, severe thunderstorms were located along a line
  extending from 22 miles north of Turner to 35 miles north of
  Chinook, moving southeast at 20 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...
  Harlem, Turner and Hogeland. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

These thunderstorms are capable of producing all types of severe
weather including extremely large hail, destructive straight line
winds and tornadoes. Move quickly to a safe shelter such as an
interior room, a bathroom, closet or basement.

&&

LAT...LON 4875 10826 4874 10832 4844 10835 4844 10842
      4822 10841 4900 10946 4900 10823
TIME...MOT...LOC 0049Z 315DEG 17KT 4915 10856 4910 10916 

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

RCG

2 follow-up statements

947 
WWUS55 KTFX 070115
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
715 PM MDT Tue Jul 6 2021

MTC005-070130-
/O.CON.KTFX.SV.W.0027.000000T0000Z-210707T0130Z/
Blaine MT-
715 PM MDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM MDT
FOR NORTHEASTERN BLAINE COUNTY...

At 714 PM MDT, severe thunderstorms were located along a line
extending from 15 miles north of Turner to 31 miles north of Chinook,
moving southeast at 20 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...
Harlem, Turner and Hogeland. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

These thunderstorms are capable of producing all types of severe
weather including extremely large hail, destructive straight line
winds and tornadoes. Move quickly to a safe shelter, such as an
interior room, a bathroom or closet or basement.

&&

LAT...LON 4875 10826 4874 10832 4844 10835 4844 10842
      4822 10841 4879 10917 4900 10916 4900 10823
TIME...MOT...LOC 0114Z 315DEG 17KT 4907 10844 4902 10904 

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

RCG

198 
WWUS55 KTFX 070122
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
722 PM MDT Tue Jul 6 2021

MTC005-070130-
/O.CON.KTFX.SV.W.0027.000000T0000Z-210707T0130Z/
Blaine MT-
722 PM MDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM MDT
FOR NORTHEASTERN BLAINE COUNTY...

At 722 PM MDT, severe thunderstorms were located along a line
extending from 14 miles north of Turner to 30 miles north of Chinook,
moving southeast at 20 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...
Harlem, Turner and Hogeland. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

These thunderstorms are capable of producing all types of severe
weather including extremely large hail, destructive straight line
winds and tornadoes. Move quickly to a safe shelter, such as an
interior room, a bathroom or closet or basement.

&&

LAT...LON 4875 10826 4874 10832 4844 10835 4844 10842
      4822 10841 4879 10917 4900 10916 4900 10823
TIME...MOT...LOC 0122Z 315DEG 17KT 4905 10841 4900 10901 

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

RCG

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 6, 6:14 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	29 min
Jul 6, 6:16 PM MDT	Special Weather Statement	TFX	Toole	29 min
Jul 6, 6:57 PM MDT	Special Weather Statement	TFX	Toole	33 min
Jul 6, 7:27 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	63 min
Jul 6, 7:30 PM MDT	Special Weather Statement	TFX	Liberty	30 min
Jul 6, 8:20 PM MDT	Tornado Warning	TFX	Blaine	25 min
Jul 6, 8:45 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	19 min
Jul 7, 1:51 PM MDT	Special Weather Statement	TFX	Beaverhead	39 min
Jul 7, 2:03 PM MDT	Special Weather Statement	TFX	Judith Basin	27 min
Jul 7, 2:18 PM MDT	Special Weather Statement	TFX	Fergus	27 min
Jul 7, 2:43 PM MDT	Special Weather Statement	TFX	Fergus	32 min
Jul 7, 2:46 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	29 min
Jul 7, 2:55 PM MDT	Special Weather Statement	TFX	Madison	50 min
Jul 7, 3:06 PM MDT	Special Weather Statement	TFX	Jefferson	54 min
Jul 7, 3:13 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	47 min
Jul 7, 3:21 PM MDT	Special Weather Statement	TFX	Fergus	24 min
Jul 7, 3:26 PM MDT	Severe Thunderstorm Warning	TFX	Jefferson, Lewis and Clark	34 min
Jul 7, 3:36 PM MDT	Special Weather Statement	TFX	Fergus	24 min
Jul 7, 3:40 PM MDT	Special Weather Statement	TFX	Lewis and Clark	35 min
Jul 7, 3:46 PM MDT	Special Weather Statement	TFX	Broadwater, Jefferson	44 min
Jul 7, 3:55 PM MDT	Special Weather Statement	TFX	Gallatin	50 min
Jul 7, 3:59 PM MDT	Special Weather Statement	TFX	Fergus	46 min
Jul 7, 4:02 PM MDT	Special Weather Statement	TFX	Broadwater, Jefferson	43 min
Jul 7, 4:30 PM MDT	Severe Thunderstorm Warning	TFX	Gallatin	30 min
Jul 7, 4:36 PM MDT	Severe Thunderstorm Warning	TFX	Gallatin	15 min
Jul 7, 4:48 PM MDT	Special Weather Statement	TFX	Silver Bow	27 min
Jul 7, 4:56 PM MDT	Special Weather Statement	TFX	Meagher	34 min
Jul 7, 5:12 PM MDT	Special Weather Statement	TFX	Judith Basin	48 min
Jul 7, 5:13 PM MDT	Special Weather Statement	TFX	Blaine	62 min
Jul 7, 5:38 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	37 min
Jul 7, 5:56 PM MDT	Special Weather Statement	TFX	Blaine	34 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.