Alert archive / Idaho / Winter Weather Advisories in 2021
Winter Weather Advisory 21, NWS Missoula, MT
NWS Missoula, MT issued this winter weather advisory at Feb 20, 2021, 7:28 AM PST for Clearwater County, Idaho County, Idaho. It was in force for 9 hr.
The area
The counties it named.
The facts
- Issued
- Feb 20, 2021, 7:28 AM PST (15:28 UTC)
- Expired
- Feb 20, 2021, 4:00 PM PST
- In force
- 9 hr
- Issued by
- NWS Missoula, MT
Counties Clearwater County, ID, Idaho County, ID
The radar
The Missoula radar (KMSX), 148 km from the middle of the area, began a volume at 15:30 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, 3.5 hours before the alert went out and 172 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
- 798 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 82 m²/s²
- 0-3 km storm-relative helicity
- 108 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
997 WWUS45 KMSO 201528 WSWMSO URGENT - WINTER WEATHER MESSAGE National Weather Service Missoula MT 828 AM MST Sat Feb 20 2021 IDZ005-202100- /O.NEW.KMSO.WW.Y.0021.210220T1528Z-210220T2100Z/ Northern Clearwater Mountains- 728 AM PST Sat Feb 20 2021 ...WINTER WEATHER ADVISORY IN EFFECT UNTIL 1 PM PST THIS AFTERNOON... * WHAT...Snow. Additional snow accumulations of 1 to 3 inches. * WHERE...Elk River, Highway 11 Pierce to Headquarters, and Pierce. * WHEN...Until 1 PM PST this afternoon. * IMPACTS...Expect sudden visibility reduction to one half mile or less with slush on the roadways associated with the intense snow showers. Travel could be affected. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ IDZ006-210000- /O.NEW.KMSO.WW.Y.0021.210220T1528Z-210221T0000Z/ Southern Clearwater Mountains- 728 AM PST Sat Feb 20 2021 ...WINTER WEATHER ADVISORY IN EFFECT UNTIL 4 PM PST THIS AFTERNOON... * WHAT...Snow. Additional snow accumulations of 1 to 4 inches. * WHERE...Dixie, Elk City, and Highway 12 Lowell to Lolo Pass. * WHEN...Until 4 PM PST this afternoon. * IMPACTS...Expect sudden visibility reduction to one half mile or less with slush on the roadways associated with the intense snow showers. Travel could be affected. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ IDZ008-210000- /O.NEW.KMSO.WW.Y.0021.210220T1700Z-210221T0000Z/ Lower Hells Canyon/Salmon River Region- 728 AM PST Sat Feb 20 2021 ...WINTER WEATHER ADVISORY IN EFFECT UNTIL 4 PM PST THIS AFTERNOON... * WHAT...Snow expected. Total snow accumulations of 1 to 2 inches. * WHERE...Whitebird Grade and Whitebird Hill. * WHEN...Until 4 PM PST this afternoon. * IMPACTS...Expect sudden visibility reduction to one half mile or less with slush on the roadways associated with the intense snow showers. Travel could be affected. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$
Nearby
Winter Weather Advisories in Idaho, 2021Every winter weather 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.