Alert archive / Montana / Frost Advisories in 2021
Frost Advisory 1, NWS Missoula, MT
NWS Missoula, MT issued this frost advisory at Aug 23, 2021, 1:21 PM MDT for 7 counties in Montana. It took effect at Aug 24, 2021, 3:00 AM MDT. It was in force for 6 hr.
The area
The counties it named.
The facts
- Issued
- Aug 23, 2021, 1:21 PM MDT (19:21 UTC)
- In effect from
- Aug 24, 2021, 3:00 AM MDT
- Expired
- Aug 24, 2021, 9:00 AM MDT
- In force
- 6 hr
- Issued by
- NWS Missoula, MT
Counties Flathead County, MT, Lake County, MT, Lincoln County, MT, Mineral County, MT, Missoula County, MT, Ravalli County, MT, Sanders County, MT
The radar
The Missoula radar (KMSX), 65 km from the middle of the area, began a volume at 19:20 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, 7.4 hours before the alert went out and 142 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
- 1114 m above ground
- 0-6 km bulk shear
- 62 kt
- 0-1 km storm-relative helicity
- -27 m²/s²
- 0-3 km storm-relative helicity
- -27 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
739 WWUS75 KMSO 231921 NPWMSO URGENT - WEATHER MESSAGE National Weather Service Missoula MT 121 PM MDT Mon Aug 23 2021 MTZ001-003>005-241500- /O.NEW.KMSO.FR.Y.0001.210824T0900Z-210824T1500Z/ Kootenai/Cabinet Region-Flathead/Mission Valleys- Lower Clark Fork Region-Missoula/Bitterroot Valleys- 121 PM MDT Mon Aug 23 2021 ...FROST ADVISORY IN EFFECT FROM 3 AM TO 9 AM MDT TUESDAY... * WHAT...Temperatures as low as 35 to 40 degrees will result in areas of frost formation. * WHERE...Kootenai/Cabinet Region, Flathead/Mission Valleys, Lower Clark Fork Region and Missoula/Bitterroot Valleys. * WHEN...From 3 AM to 9 AM MDT Tuesday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. && $$
1 follow-up statement
656 WWUS75 KMSO 241447 NPWMSO URGENT - WEATHER MESSAGE National Weather Service Missoula MT 847 AM MDT Tue Aug 24 2021 MTZ001-003>005-241600- /O.EXP.KMSO.FR.Y.0001.000000T0000Z-210824T1500Z/ Kootenai/Cabinet Region-Flathead/Mission Valleys- Lower Clark Fork Region-Missoula/Bitterroot Valleys- 847 AM MDT Tue Aug 24 2021 ...FROST ADVISORY WILL EXPIRE AT 9 AM MDT THIS MORNING... Temperatures are warming, the threat of frost is ending. $$
Nearby
Frost Advisories in Montana, 2021Every frost advisory 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.