Alert archive / Montana / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 60, NWS Great Falls, MT
NWS Great Falls, MT issued this severe thunderstorm warning at Aug 8, 2021, 4:29 PM MDT for Beaverhead County, Gallatin County, Madison County, Montana. It was in force for 61 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
- Aug 8, 2021, 4:29 PM MDT (22:29 UTC)
- Expired
- Aug 8, 2021, 5:30 PM MDT
- In force
- 61 min
- Issued by
- NWS Great Falls, MT
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Beaverhead County, MT, Gallatin County, MT, Madison County, MT
The radar
The Pocatello radar (KSFX), 227 km from the middle of the area, began a volume at 22:31 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 8, 5:16 PM MDT | TSTM WND GST 50 | 3 Ssw Ennis, MT | MESONET STATION ENNM8 ENNIS RAWS. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Great_falls, MT (KTFX), launched 12:00Z, 10.5 hours before the alert went out and 290 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.
- Mixed-layer CAPE
- 16 J/kg
- Mixed-layer CIN
- -213 J/kg
- Mixed-layer LCL
- 2411 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 81 m²/s²
- 0-3 km storm-relative helicity
- 174 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
097
WUUS55 KTFX 082229
SVRTFX
MTC001-031-057-082330-
/O.NEW.KTFX.SV.W.0060.210808T2229Z-210808T2330Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Great Falls MT
429 PM MDT Sun Aug 8 2021
The National Weather Service in Great Falls has issued a
* Severe Thunderstorm Warning for...
Madison County in southwestern Montana...
South central Beaverhead County in southwestern Montana...
Northern Gallatin County in south central Montana...
* Until 530 PM MDT.
* At 429 PM MDT, areas of severe wind gusts were located along a
line extending from 11 miles southeast of Toston to 6 miles north
of Leadore, moving northeast at 45 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Bozeman, Dillon, Sheridan, Virginia City, Belgrade, Three Forks,
Manhattan, Ennis, Lima, Pony, Alder, Harrison, Dell, Bannack Pass,
Cameron, Missouri Headwaters State Park, Snowline, Maudlow, Four
Corners and Amsterdam.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4440 11289 4445 11300 4468 11307 4477 11313
4482 11325 4582 11185 4580 11171 4593 11150
4600 11141 4618 11133 4620 11081 4578 11079
4448 11257 4450 11269 4448 11278 4436 11285
TIME...MOT...LOC 2229Z 234DEG 37KT 4607 11125 4477 11333
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
HART2 follow-up statements
859
WWUS55 KTFX 082304
SVSTFX
Severe Weather Statement
National Weather Service Great Falls MT
504 PM MDT Sun Aug 8 2021
MTC001-031-057-082330-
/O.CON.KTFX.SV.W.0060.000000T0000Z-210808T2330Z/
Madison MT-Beaverhead MT-Gallatin MT-
504 PM MDT Sun Aug 8 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM MDT
FOR MADISON...SOUTH CENTRAL BEAVERHEAD AND NORTHERN GALLATIN
COUNTIES...
At 501 PM MDT, sporadic areas of severe wind gusts continue
across the warned area. Many locations within the warned area
have reported wind gusts of 50 to 55 mph over the last 30 minutes. A
few gusts to around 60 mph are likely.
HAZARD...60 mph wind gusts.
SOURCE...Trained weather spotters.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Bozeman, Dillon, Sheridan, Virginia City, Belgrade, Three Forks,
Manhattan, Ennis, Lima, Pony, Alder, Harrison, Dell, Bannack Pass,
Cameron, Missouri Headwaters State Park, Snowline, Maudlow, Four
Corners and Amsterdam.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4440 11289 4445 11300 4468 11307 4477 11313
4482 11325 4582 11185 4580 11171 4593 11150
4600 11141 4618 11133 4620 11081 4578 11079
4448 11257 4450 11269 4448 11278 4436 11285
TIME...MOT...LOC 2301Z 234DEG 37KT 4626 11088 4496 11296
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
HART034
WWUS55 KTFX 082327
SVSTFX
Severe Weather Statement
National Weather Service Great Falls MT
527 PM MDT Sun Aug 8 2021
MTC001-031-057-082336-
/O.EXP.KTFX.SV.W.0060.000000T0000Z-210808T2330Z/
Madison MT-Beaverhead MT-Gallatin MT-
527 PM MDT Sun Aug 8 2021
...THE SEVERE THUNDERSTORM WARNING FOR MADISON...SOUTH CENTRAL
BEAVERHEAD AND NORTHERN GALLATIN COUNTIES WILL EXPIRE AT 530 PM
MDT...
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However gusty
winds of 50 to 55 mph are still possible.
LAT...LON 4440 11289 4445 11300 4468 11307 4477 11313
4482 11325 4582 11185 4580 11171 4593 11150
4600 11141 4618 11133 4620 11081 4578 11079
4448 11257 4450 11269 4448 11278 4436 11285
TIME...MOT...LOC 2326Z 234DEG 37KT 4640 11059 4511 11268
$$
HARTThe office that day
Everything else NWS Great Falls, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 8, 1:26 PM MDT | Special Weather Statement | TFX | Beaverhead, Broadwater, Gallatin, Jefferson, Madison, Meagher | 79 min |
| Aug 8, 2:37 PM MDT | Special Weather Statement | TFX | Beaverhead, Broadwater, Gallatin, Jefferson, Madison | 83 min |
| Aug 8, 2:46 PM MDT | Special Weather Statement | TFX | Cascade, Judith Basin, Meagher | 59 min |
| Aug 8, 3:09 PM MDT | Areal Flood Advisory | TFX | Cascade | 51 min |
| Aug 8, 3:31 PM MDT | Special Weather Statement | TFX | Fergus, Judith Basin, Meagher | 59 min |
| Aug 8, 4:03 PM MDT | Special Weather Statement | TFX | Beaverhead, Gallatin, Madison, Meagher | 57 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.