Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 55, NWS Great Falls, MT

August 4, 2021Glacier County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Aug 4, 2021, 3:55 PM MDT for Glacier County, Montana. It was in force for 12 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 4, 2021, 3:55 PM MDT (21:55 UTC)
Expired: Aug 4, 2021, 4:07 PM MDT
In force: 12 min
Issued by: NWS Great Falls, MT
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County Glacier County, MT

The radar

The Great Falls radar (KTFX), 170 km from the middle of the area, began a volume at 21:58 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

Great_falls, MT (KTFX), launched 12:00Z, 9.9 hours before the alert went out and 203 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 3035 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: -14 m²/s²
0-3 km storm-relative helicity: 45 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

489 
WUUS55 KTFX 042155
SVRTFX
MTC035-042230-
/O.NEW.KTFX.SV.W.0055.210804T2155Z-210804T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Great Falls MT
355 PM MDT Wed Aug 4 2021

The National Weather Service in Great Falls has issued a

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

* Until 430 PM MDT.

* At 355 PM MDT, a severe thunderstorm was located 13 miles northwest
  of Cut Bank, moving east at 20 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Santa Rita.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4879 11258 4890 11256 4893 11220 4869 11220
TIME...MOT...LOC 2155Z 278DEG 17KT 4882 11246 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

CMC

2 follow-up statements

487 
WWUS55 KTFX 042201
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
401 PM MDT Wed Aug 4 2021

MTC035-042230-
/O.CON.KTFX.SV.W.0055.000000T0000Z-210804T2230Z/
Glacier MT-
401 PM MDT Wed Aug 4 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM MDT
FOR EAST CENTRAL GLACIER COUNTY...

At 401 PM MDT, a severe thunderstorm was located 13 miles north of
Cut Bank, moving east at 20 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Santa Rita.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4879 11251 4889 11250 4893 11220 4870 11220
TIME...MOT...LOC 2201Z 278DEG 17KT 4882 11242 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

CMC

715 
WWUS55 KTFX 042207
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
407 PM MDT Wed Aug 4 2021

MTC035-042216-
/O.CAN.KTFX.SV.W.0055.000000T0000Z-210804T2230Z/
Glacier MT-
407 PM MDT Wed Aug 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL GLACIER COUNTY IS
CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled. However, small hail is 
still possible with this thunderstorm.

LAT...LON 4879 11251 4889 11250 4893 11220 4870 11220
TIME...MOT...LOC 2206Z 278DEG 17KT 4882 11238 

$$

CMC

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 3, 6:29 PM MDT	Special Weather Statement	TFX	Blaine	31 min
Aug 3, 6:32 PM MDT	Special Weather Statement	TFX	Meagher	28 min
Aug 4, 2:35 PM MDT	Red Flag Warning	TFX	Broadwater, Cascade, Fergus, Gallatin, Jefferson, Judith Basin and 3 more	33 hr
Aug 4, 3:03 PM MDT	Special Weather Statement	TFX	Glacier	42 min
Aug 4, 3:18 PM MDT	Severe Thunderstorm Warning	TFX	Glacier	42 min
Aug 4, 3:36 PM MDT	Special Weather Statement	TFX	Cascade	24 min
Aug 4, 3:44 PM MDT	Special Weather Statement	TFX	Glacier	31 min
Aug 4, 3:59 PM MDT	Special Weather Statement	TFX	Glacier	46 min
Aug 4, 4:09 PM MDT	Special Weather Statement	TFX	Toole	51 min
Aug 4, 4:13 PM MDT	Special Weather Statement	TFX	Cascade	32 min
Aug 4, 4:14 PM MDT	Special Weather Statement	TFX	Cascade	31 min
Aug 4, 4:15 PM MDT	Special Weather Statement	TFX	Teton	30 min
Aug 4, 4:18 PM MDT	Special Weather Statement	TFX	Lewis and Clark	27 min
Aug 4, 4:23 PM MDT	Special Weather Statement	TFX	Pondera	37 min
Aug 4, 4:26 PM MDT	Special Weather Statement	TFX	Glacier	49 min
Aug 4, 4:41 PM MDT	Special Weather Statement	TFX	Cascade	49 min
Aug 4, 4:45 PM MDT	Special Weather Statement	TFX	Teton	45 min
Aug 4, 4:47 PM MDT	Special Weather Statement	TFX	Cascade	43 min
Aug 4, 4:48 PM MDT	Special Weather Statement	TFX	Judith Basin	27 min
Aug 4, 4:51 PM MDT	Special Weather Statement	TFX	Glacier	24 min
Aug 4, 4:53 PM MDT	Special Weather Statement	TFX	Toole	37 min
Aug 4, 4:56 PM MDT	Special Weather Statement	TFX	Toole	34 min
Aug 4, 4:57 PM MDT	Special Weather Statement	TFX	Pondera	33 min
Aug 4, 5:01 PM MDT	Special Weather Statement	TFX	Teton	29 min
Aug 4, 5:11 PM MDT	Special Weather Statement	TFX	Meagher	34 min
Aug 4, 5:17 PM MDT	Special Weather Statement	TFX	Glacier	28 min
Aug 4, 5:18 PM MDT	Special Weather Statement	TFX	Teton	27 min
Aug 4, 5:23 PM MDT	Special Weather Statement	TFX	Teton	37 min
Aug 4, 5:25 PM MDT	Special Weather Statement	TFX	Cascade	35 min
Aug 4, 5:25 PM MDT	Special Weather Statement	TFX	Liberty	50 min
Aug 4, 5:32 PM MDT	Special Weather Statement	TFX	Teton	28 min
Aug 4, 5:37 PM MDT	Special Weather Statement	TFX	Teton	23 min
Aug 4, 5:42 PM MDT	Special Weather Statement	TFX	Meagher	33 min
Aug 4, 5:50 PM MDT	Special Weather Statement	TFX	Toole	40 min
Aug 4, 5:57 PM MDT	Special Weather Statement	TFX	Cascade	33 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.