Alert archive / Montana / Special Weather Statements in 2021
Special Weather Statement, NWS Missoula, MT
NWS Missoula, MT issued this special weather statement at Aug 5, 2021, 3:20 PM MDT for Granite County, Ravalli County, Montana. It was in force for 55 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 5, 2021, 3:20 PM MDT (21:20 UTC)
- Expired
- Aug 5, 2021, 4:15 PM MDT
- In force
- 55 min
- Issued by
- NWS Missoula, MT
- Hail
- 0.00 in
- Wind
- 30
Counties Granite County, MT, Ravalli County, MT
The radar
The Missoula radar (KMSX), 39 km from the middle of the area, began a volume at 21:19 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
Spokane, WA (KOTX), launched 12:00Z, 9.3 hours before the alert went out and 216 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
- 40 J/kg
- Mixed-layer CIN
- -512 J/kg
- Mixed-layer LCL
- 2758 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 20 m²/s²
- 0-3 km storm-relative helicity
- 100 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
703
WWUS85 KMSO 052120
SPSMSO
Special Weather Statement
National Weather Service Missoula MT
320 PM MDT Thu Aug 5 2021
IDZ006-MTZ004>007-043-052215-
Southern Clearwater Mountains ID-Bitterroot/Sapphire Mountains MT-
Missoula/Bitterroot Valleys MT-Lower Clark Fork Region MT-
Butte/Blackfoot Region MT-Potomac/Seeley Lake Region MT-
320 PM MDT Thu Aug 5 2021
...Strong thunderstorms will impact portions of northeastern Idaho,
eastern Mineral, southwestern Missoula, northeastern Ravalli and
northwestern Granite Counties through 415 PM MDT/315 PM PDT/...
At 319 PM MDT/219 PM PDT/, Doppler radar was tracking outflow winds
associated with thunderstorms along a line extending from 7 miles
south of Alberton to 21 miles east of Hamilton. Movement was east at
35 mph.
HAZARD...Winds in excess of 30 to 40 mph.
SOURCE...Recent observations show this line has a history of
producing winds of 30 to 40 mph.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Missoula, Hamilton, Lolo, Stevensville, Wye, Florence, Victor,
Bonner-West Riverside, East Missoula, Woodside, Pinesdale,
Grantsdale, Quigley, Corvallis, Clinton, Turah, Bell Crossing and
Skalkaho Pass.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4705 11392 4638 11324 4606 11411 4691 11463
TIME...MOT...LOC 2119Z 248DEG 29KT 4690 11447 4617 11371
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...30 MPH
$$The office that day
Everything else NWS Missoula, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 4, 6:21 PM MDT | Special Weather Statement | MSO | Flathead | 24 min |
| Aug 4, 6:31 PM MDT | Special Weather Statement | MSO | Lake | 14 min |
| Aug 4, 7:57 PM MDT | Special Weather Statement | MSO | Lake | 18 min |
| Aug 4, 8:03 PM MDT | Severe Thunderstorm Warning | MSO | Lake | 27 min |
| Aug 4, 8:26 PM MDT | Severe Thunderstorm Warning | MSO | Lake | 34 min |
| Aug 5, 2:27 PM MDT | Special Weather Statement | MSO | Mineral, Ravalli | 33 min |
| Aug 5, 4:12 PM MDT | Special Weather Statement | MSO | Deer Lodge, Silver Bow | 48 min |
| Aug 5, 4:19 PM MDT | Special Weather Statement | MSO | Ravalli | 56 min |
| Aug 5, 5:03 PM MDT | Severe Thunderstorm Warning | MSO | Powell | 42 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.