Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 39, NWS Billings, MT

July 7, 2021Custer County, Montana

NWS Billings, MT issued this severe thunderstorm warning at Jul 7, 2021, 8:14 PM MDT for Custer County, Montana. It was in force for 46 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: Jul 7, 2021, 8:14 PM MDT (02:14 UTC)
Expired: Jul 7, 2021, 9:00 PM MDT
In force: 46 min
Issued by: NWS Billings, MT
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Custer County, MT

What was reported inside it

Time	Report	Where	Remark
Jul 7, 8:35 PM MDT	TSTM WND GST 82	18 Ssw Mizpah, 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
Jul 7, 3:03 PM MDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 2.2 hours before the alert went out and 265 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: 201 J/kg
Mixed-layer CIN: -154 J/kg
Mixed-layer LCL: 2168 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 107 m²/s²
0-3 km storm-relative helicity: 209 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.8

Open this sounding in Storm Lab

The text

As transmitted.

429 
WUUS55 KBYZ 080214
SVRBYZ
MTC017-080300-
/O.NEW.KBYZ.SV.W.0039.210708T0214Z-210708T0300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Billings MT
814 PM MDT Wed Jul 7 2021

The National Weather Service in Billings has issued a

* Severe Thunderstorm Warning for...
  Southeastern Custer County in southeastern Montana...

* Until 900 PM MDT.

* At 813 PM MDT, a severe thunderstorm was located 12 miles north of 
  Volborg, or 29 miles southeast of Miles City, moving east at 30 
  mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Volborg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4613 10494 4579 10494 4582 10573 4612 10578
      4618 10490 4614 10490
TIME...MOT...LOC 0213Z 272DEG 39KT 4602 10559 

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

Tesar

1 follow-up statement

533 
WWUS55 KBYZ 080236
SVSBYZ

Severe Weather Statement
National Weather Service Billings MT
836 PM MDT Wed Jul 7 2021

MTC017-080300-
/O.CON.KBYZ.SV.W.0039.000000T0000Z-210708T0300Z/
Custer MT-
836 PM MDT Wed Jul 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM MDT
FOR SOUTHEASTERN CUSTER COUNTY...

At 835 PM MDT, a severe thunderstorm was located 20 miles northeast 
of Volborg, or 37 miles southeast of Miles City, moving east at 30 
mph.

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

SOURCE...Radar indicated.

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

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4613 10494 4579 10494 4581 10552 4613 10561
      4618 10490 4614 10490
TIME...MOT...LOC 0235Z 274DEG 30KT 4600 10532 

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

Tesar

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 7, 6:21 PM MDT	Special Weather Statement	BYZ	Treasure	24 min
Jul 7, 6:35 PM MDT	Severe Thunderstorm Warning	BYZ	Big Horn, Carbon, Golden Valley, Musselshell, Stillwater, Yellowstone	55 min
Jul 7, 6:47 PM MDT	Special Weather Statement	BYZ	Rosebud	28 min
Jul 7, 7:00 PM MDT	Severe Thunderstorm Warning	BYZ	Rosebud	30 min
Jul 7, 7:24 PM MDT	Severe Thunderstorm Warning	BYZ	Big Horn, Musselshell, Rosebud, Treasure, Yellowstone	66 min
Jul 7, 7:31 PM MDT	Severe Thunderstorm Warning	BYZ	Custer, Rosebud	29 min
Jul 7, 7:53 PM MDT	Severe Thunderstorm Warning	BYZ	Custer	52 min
Jul 7, 8:23 PM MDT	Severe Thunderstorm Warning	BYZ	Big Horn, Rosebud	52 min
Jul 7, 8:59 PM MDT	Severe Thunderstorm Warning	BYZ	Custer	31 min
Jul 7, 9:13 PM MDT	Severe Thunderstorm Warning	BYZ	Big Horn, Powder River, Rosebud	62 min
Jul 7, 9:19 PM MDT	Severe Thunderstorm Warning	BYZ	Carter	56 min
Jul 7, 9:50 PM MDT	Special Weather Statement	BYZ	Fallon	55 min
Jul 7, 10:05 PM MDT	Special Weather Statement	BYZ	Carter	40 min
Jul 7, 10:08 PM MDT	Special Weather Statement	BYZ	Powder River	52 min
Jul 7, 10:59 PM MDT	Special Weather Statement	BYZ	Carter, Powder River	61 min
Jul 7, 11:59 PM MDT	Special Weather Statement	BYZ	Carter	46 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.