Alert archive / Montana / Special Weather Statements in 2021
Special Weather Statement, NWS Great Falls, MT
NWS Great Falls, MT issued this special weather statement at Jul 20, 2021, 4:21 PM MDT for Gallatin County, Montana. It was in force for 24 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 20, 2021, 4:21 PM MDT (22:21 UTC)
- Expired
- Jul 20, 2021, 4:45 PM MDT
- In force
- 24 min
- Issued by
- NWS Great Falls, MT
County Gallatin County, MT
The radar
The Great Falls radar (KTFX), 199 km from the middle of the area, began a volume at 22:24 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, 10.4 hours before the alert went out and 206 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1591 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- -28 m²/s²
- 0-3 km storm-relative helicity
- 225 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
529 WWUS85 KTFX 202221 SPSTFX Special Weather Statement National Weather Service Great Falls MT 421 PM MDT Tue Jul 20 2021 MTZ015-055-202245- Madison-Gallatin- 421 PM MDT Tue Jul 20 2021 ...A STRONG THUNDERSTORM WILL AFFECT EASTERN MADISON AND NORTHERN GALLATIN COUNTIES... At 420 PM MDT, a strong thunderstorm was located 14 miles southwest of Belgrade, or 17 miles west of Bozeman, moving northeast at 25 mph. Winds in excess of 30 mph are possible with this storm. Locations impacted include... Bozeman, Belgrade, Manhattan, Four Corners, Amsterdam, Bozeman Hot Springs and Church Hill. This includes the following highways... Interstate 90 between mile markers 289 and 305. Highway 191 between mile markers 79 and 85. Torrential rainfall is also occurring with this storm, and may cause localized flooding. Do not drive your vehicle through flooded roadways. LAT...LON 4551 11136 4563 11155 4593 11127 4576 11098 TIME...MOT...LOC 2220Z 220DEG 22KT 4563 11139 $$ SC
The office that day
Everything else NWS Great Falls, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 2:04 PM MDT | Fire Weather Watch | TFX | Blaine, Glacier, Hill, Jefferson, Lewis and Clark, Liberty and 5 more | 23 hr |
| Jul 20, 2:38 PM MDT | Special Weather Statement | TFX | Broadwater | 22 min |
| Jul 20, 2:56 PM MDT | Special Weather Statement | TFX | Madison | 34 min |
| Jul 20, 3:14 PM MDT | Special Weather Statement | TFX | Madison | 31 min |
| Jul 20, 3:35 PM MDT | Special Weather Statement | TFX | Deer Lodge | 25 min |
| Jul 20, 3:54 PM MDT | Special Weather Statement | TFX | Madison | 36 min |
| Jul 20, 4:24 PM MDT | Special Weather Statement | TFX | Gallatin | 36 min |
| Jul 20, 5:11 PM MDT | Special Weather Statement | TFX | Broadwater | 34 min |
| Jul 20, 5:16 PM MDT | Special Weather Statement | TFX | Lewis and Clark | 29 min |
| Jul 20, 5:47 PM MDT | Special Weather Statement | TFX | Lewis and Clark, Meagher | 28 min |
| Jul 20, 5:53 PM MDT | Special Weather Statement | TFX | Jefferson | 37 min |
Nearby
Special Weather Statements in Montana, 2021Every special weather statement 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.