Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 18, NWS Great Falls, MT

June 24, 2021Fergus County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jun 24, 2021, 5:59 PM MDT for Fergus County, Montana. It was in force for 31 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: Jun 24, 2021, 5:59 PM MDT (23:59 UTC)
Expired: Jun 24, 2021, 6:30 PM MDT
In force: 31 min
Issued by: NWS Great Falls, MT
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

County Fergus County, MT

The radar

The Billings radar (KBLX), 109 km from the middle of the area, began a volume at 00:02 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, 12.0 hours before the alert went out and 158 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: 10 J/kg
Mixed-layer CIN: -138 J/kg
Mixed-layer LCL: 2437 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 105 m²/s²
0-3 km storm-relative helicity: 109 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

398 
WUUS55 KTFX 242359
SVRTFX
MTC027-250030-
/O.NEW.KTFX.SV.W.0018.210624T2359Z-210625T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Great Falls MT
559 PM MDT Thu Jun 24 2021

The National Weather Service in Great Falls has issued a

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

* Until 630 PM MDT.

* At 558 PM MDT, a severe thunderstorm was located 11 miles south of
  Grass Range, or 23 miles southwest of Winnett, moving east at 40
  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.

* This severe thunderstorm will remain over mainly rural areas of
  southeastern Fergus County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 4676 10863 4675 10868 4677 10892 4696 10889
      4698 10861
TIME...MOT...LOC 2358Z 272DEG 36KT 4685 10880 

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

Ludwig

1 follow-up statement

080 
WWUS55 KTFX 250021
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
621 PM MDT Thu Jun 24 2021

MTC027-250030-
/O.EXP.KTFX.SV.W.0018.000000T0000Z-210625T0030Z/
Fergus MT-
621 PM MDT Thu Jun 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN FERGUS COUNTY
WILL EXPIRE AT 630 PM MDT...
        
The storm which prompted the warning has moved out of the 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 4676 10863 4675 10868 4677 10892 4696 10889
      4698 10861
TIME...MOT...LOC 0020Z 272DEG 36KT 4684 10848 

$$

Ludwig

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 24, 2:05 PM MDT	Special Weather Statement	TFX	Cascade	40 min
Jun 24, 3:57 PM MDT	Special Weather Statement	TFX	Teton	33 min
Jun 24, 4:07 PM MDT	Special Weather Statement	TFX	Meagher	23 min
Jun 24, 4:25 PM MDT	Special Weather Statement	TFX	Teton	35 min
Jun 24, 4:29 PM MDT	Severe Thunderstorm Warning	TFX	Fergus, Judith Basin	31 min
Jun 24, 4:55 PM MDT	Severe Thunderstorm Warning	TFX	Fergus, Judith Basin	35 min
Jun 24, 5:16 PM MDT	Special Weather Statement	TFX	Fergus	44 min
Jun 24, 5:29 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	31 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.