Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 34, NWS Great Falls, MT

July 7, 2021Gallatin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 7, 2021, 4:36 PM MDT for Gallatin County, Montana. It was in force for 15 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 7, 2021, 4:36 PM MDT (22:36 UTC)
Expired: Jul 7, 2021, 4:51 PM MDT
In force: 15 min
Issued by: NWS Great Falls, MT
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Gallatin County, MT

The radar

The Billings radar (KBLX), 185 km from the middle of the area, began a volume at 22:37 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, 10.6 hours before the alert went out and 199 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: 42 J/kg
Mixed-layer CIN: -360 J/kg
Mixed-layer LCL: 2232 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: -61 m²/s²
0-3 km storm-relative helicity: 70 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

001 
WUUS55 KTFX 072236
SVRTFX
MTC031-072315-
/O.NEW.KTFX.SV.W.0034.210707T2236Z-210707T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Great Falls MT
436 PM MDT Wed Jul 7 2021

The National Weather Service in Great Falls has issued a

* Severe Thunderstorm Warning for...
  East central Gallatin County in south central Montana...

* Until 515 PM MDT.

* At 435 PM MDT, a severe thunderstorm was located near Bozeman,
  moving east at 20 mph.

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

  SOURCE...Public report.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Bozeman.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4570 11112 4584 11080 4561 11080 4559 11106
TIME...MOT...LOC 2235Z 256DEG 19KT 4567 11097 

HAIL...0.75IN
WIND...60MPH
 
$$

CMC

2 follow-up statements

517 
WWUS55 KTFX 072240
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
440 PM MDT Wed Jul 7 2021

MTC031-072315-
/O.CON.KTFX.SV.W.0034.000000T0000Z-210707T2315Z/
Gallatin MT-
440 PM MDT Wed Jul 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM MDT
FOR EAST CENTRAL GALLATIN COUNTY...

At 440 PM MDT, a severe thunderstorm was located 7 miles east of
Bozeman, moving east at 25 mph.

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

SOURCE...Public.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Bozeman.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4584 11080 4561 11080 4559 11101 4574 11104
TIME...MOT...LOC 2240Z 264DEG 23KT 4566 11089 

HAIL...0.75IN
WIND...60MPH
 
$$

CMC

315 
WWUS55 KTFX 072251
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
451 PM MDT Wed Jul 7 2021

MTC031-072301-
/O.CAN.KTFX.SV.W.0034.000000T0000Z-210707T2315Z/
Gallatin MT-
451 PM MDT Wed Jul 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL GALLATIN COUNTY
IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

LAT...LON 4584 11080 4561 11080 4559 11101 4574 11104
TIME...MOT...LOC 2250Z 256DEG 19KT 4567 11081 

$$

CMC

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, 6:50 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	40 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, 4:48 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.