Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 49, NWS Billings, MT

August 26, 2021Big Horn County, Montana

NWS Billings, MT issued this severe thunderstorm warning at Aug 26, 2021, 7:21 PM MDT for Big Horn County, Montana. It was in force for 54 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 26, 2021, 7:21 PM MDT (01:21 UTC)
Expired
Aug 26, 2021, 8:15 PM MDT
In force
54 min
Issued by
NWS Billings, MT
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

County Big Horn County, MT

The radar

The Billings radar (KBLX), 58 km from the middle of the area, began a volume at 01:23 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

Riverton, WY (KRIW), launched 00:00Z, 1.4 hours before the alert went out and 263 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-pSkew-T log-p diagram, Riverton, WY at 00:00Z on 2021-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 154 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 00:00Z on 2021-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
154 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
3406 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

059 
WUUS55 KBYZ 270121
SVRBYZ
MTC003-270215-
/O.NEW.KBYZ.SV.W.0049.210827T0121Z-210827T0215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Billings MT
721 PM MDT Thu Aug 26 2021

The National Weather Service in Billings has issued a

* Severe Thunderstorm Warning for...
  Western Big Horn County in south central Montana...

* Until 815 PM MDT.

* At 721 PM MDT, a severe thunderstorm was located 14 miles east of
  Pryor, or 29 miles southeast of Billings, moving east at 15 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.

* Locations impacted include...
  Fort Smith, Bighorn Lake and Crow Indian Reservation. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4535 10834 4546 10832 4549 10832 4549 10820
      4552 10819 4552 10781 4526 10785
TIME...MOT...LOC 0121Z 277DEG 13KT 4543 10822 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Carrothers
2 follow-up statements
619 
WWUS55 KBYZ 270147
SVSBYZ

Severe Weather Statement
National Weather Service Billings MT
747 PM MDT Thu Aug 26 2021

MTC003-270215-
/O.CON.KBYZ.SV.W.0049.000000T0000Z-210827T0215Z/
Big Horn MT-
747 PM MDT Thu Aug 26 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM MDT
FOR WESTERN BIG HORN COUNTY...

At 747 PM MDT, a severe thunderstorm was located 10 miles northwest
of Fort Smith, or 31 miles southwest of Hardin, moving east at 15
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.

Locations impacted include...
Crow Indian Reservation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4539 10821 4552 10819 4552 10781 4532 10784
TIME...MOT...LOC 0147Z 277DEG 13KT 4542 10809 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Carrothers
731 
WWUS55 KBYZ 270206
SVSBYZ

Severe Weather Statement
National Weather Service Billings MT
806 PM MDT Thu Aug 26 2021

MTC003-270216-
/O.EXP.KBYZ.SV.W.0049.000000T0000Z-210827T0215Z/
Big Horn MT-
806 PM MDT Thu Aug 26 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN BIG HORN COUNTY WILL
EXPIRE AT 815 PM MDT...
                
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 will be allowed to expire.  However heavy rain
is still possible with this thunderstorm.

LAT...LON 4539 10821 4552 10819 4552 10781 4532 10784
TIME...MOT...LOC 0206Z 277DEG 13KT 4541 10799 

$$

Carrothers

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 26, 6:50 PM MDTSpecial Weather StatementBYZMusselshell25 min
Aug 26, 7:13 PM MDTSpecial Weather StatementBYZTreasure47 min
Aug 26, 7:15 PM MDTSpecial Weather StatementBYZBig Horn30 min
Aug 26, 7:58 PM MDTSpecial Weather StatementBYZTreasure62 min
Aug 26, 8:22 PM MDTSpecial Weather StatementBYZBig Horn23 min
Aug 26, 8:57 PM MDTSpecial Weather StatementBYZRosebud63 min
Aug 26, 9:02 PM MDTSpecial Weather StatementBYZBig Horn28 min
Aug 26, 9:27 PM MDTSpecial Weather StatementBYZBig Horn33 min
Aug 26, 9:57 PM MDTSpecial Weather StatementBYZCuster, Rosebud63 min
Aug 26, 10:57 PM MDTSpecial Weather StatementBYZ63 min
Aug 27, 2:48 PM MDTSpecial Weather StatementBYZYellowstone42 min
Aug 27, 3:33 PM MDTSpecial Weather StatementBYZCarter42 min
Aug 27, 4:14 PM MDTSpecial Weather StatementBYZCarter31 min

Nearby

Severe Thunderstorm Warnings in Montana, 2021Every 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.