Alert archive / Idaho / Winter Weather Advisories in 2021
Winter Weather Advisory 21, NWS Spokane, WA
NWS Spokane, WA issued this winter weather advisory at Mar 20, 2021, 1:46 PM PDT for 4 counties in Idaho. It took effect at Mar 21, 2021, 5:00 PM PDT. It was in force for 18 hr.
The area
The counties it named.
The facts
- Issued
- Mar 20, 2021, 1:46 PM PDT (20:46 UTC)
- In effect from
- Mar 21, 2021, 5:00 PM PDT
- Expired
- Mar 22, 2021, 11:00 AM PDT
- In force
- 18 hr
- Issued by
- NWS Spokane, WA
Counties Benewah County, ID, Kootenai County, ID, Latah County, ID, Shoshone County, ID
The radar
The Spokane radar (KOTX), 97 km from the middle of the area, began a volume at 20:47 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, 8.8 hours before the alert went out and 49 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
- 1206 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 102 m²/s²
- 0-3 km storm-relative helicity
- 94 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
006 WWUS46 KOTX 202046 WSWOTX URGENT - WINTER WEATHER MESSAGE National Weather Service Spokane WA 146 PM PDT Sat Mar 20 2021 ...LATE SEASON SNOW EXPECTED TO IMPACT TRAVEL OVER PASSES... .An incoming system is expected to bring several inches of snow to the higher terrains of the Cascades starting late Sunday evening and lasting through Monday morning. The late season snow is expected to bring travel impacts in the area. WAZ042-210945- /O.NEW.KOTX.WW.Y.0021.210322T0000Z-210322T1800Z/ East Slopes Northern Cascades- Including the cities of Holden Village, Plain, Stevens Pass, Mazama, and Stehekin 146 PM PDT Sat Mar 20 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM SUNDAY TO 11 AM PDT MONDAY FOR THE CASCADE CREST INCLUDING HIGHWAY 2 BETWEEN COLES CORNER AND STEVENS PASS... * WHAT...Snow expected for the Cascade Crest including Highway 2 between Coles Corner and Stevens Pass. Total snow accumulations 6 to 10 inches above 4000 feet and 3 to 6 inches above 3000 feet * WHERE...Holden Village, Plain, Stevens Pass, Mazama, and Stehekin. * WHEN...From 5 PM Sunday to 11 AM PDT Monday. * IMPACTS...Travel could be very difficult. The hazardous conditions could impact the Monday morning commute. Roads, and especially bridges and overpasses, will likely become slick and hazardous. 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. && $$ JCLEV
4 follow-up statements
147 WWUS46 KOTX 210910 WSWOTX URGENT - WINTER WEATHER MESSAGE National Weather Service Spokane WA 210 AM PDT Sun Mar 21 2021 ...LATE SEASON SNOW EXPECTED TO IMPACT TRAVEL OVER PASSES... .An incoming system is expected to bring several inches of snow to the higher terrains of the Cascades starting late Sunday evening and lasting through Monday morning. The late season snow is expected to bring impacts to travel in the area. WAZ042-220200- /O.CON.KOTX.WW.Y.0021.210322T0000Z-210322T1800Z/ East Slopes Northern Cascades- Including the cities of Holden Village, Plain, Stevens Pass, Mazama, and Stehekin 210 AM PDT Sun Mar 21 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 5 PM THIS AFTERNOON TO 11 AM PDT MONDAY FOR THE CASCADE CREST INCLUDING HIGHWAY 2 BETWEEN COLES CORNER AND STEVENS PASS... * WHAT...Snow expected for the Cascade Crest including Highway 2 between Coles Corner and Stevens Pass. Total snow accumulations 6 to 10 inches above 4000 feet and 3 to 6 inches above 3000 feet * WHERE...Holden Village, Plain, Stevens Pass, Mazama, and Stehekin. * WHEN...From 5 PM this afternoon to 11 AM PDT Monday. * IMPACTS...Travel could be very difficult. The hazardous conditions could impact the Monday morning commute. Roads, and especially bridges and overpasses, will likely become slick and hazardous. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ OTX
414 WWUS46 KOTX 212007 WSWOTX URGENT - WINTER WEATHER MESSAGE National Weather Service Spokane WA 107 PM PDT Sun Mar 21 2021 ...LATE SEASON SNOW EXPECTED TO IMPACT TRAVEL OVER PASSES... .An incoming system is expected to bring several inches of snow to the Cascade Crest and Central Panhandle Mountains of Idaho. Snow will spread into the region Sunday evening and become moderate at times overnight into early Monday morning. The late season snow is expected to bring impacts to travel in the area. IDZ004-220800- /O.EXB.KOTX.WW.Y.0021.210322T0600Z-210322T1800Z/ Central Panhandle Mountains- Including the cities of Fourth Of July Pass, Wallace, Osburn, Dobson Pass, Kellogg, St. Maries, Mullan, and Pinehurst 107 PM PDT Sun Mar 21 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM 11 PM THIS EVENING TO 11 AM PDT MONDAY... * WHAT...Snow expected. Total snow accumulations between 4 to 7 inches in the mountains and 1 to 3 inches in the valleys. * WHERE...Fourth Of July Pass, Wallace, Osburn, Dobson Pass, Kellogg, St. Maries, Mullan, and Pinehurst. * WHEN...From 11 PM this evening to 11 AM PDT Monday. * IMPACTS...Be prepared for wintry travel, especially across Lookout Pass. Slushy wet snow accumulations will be possible in the valleys. 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. && $$ WAZ042-220800- /O.CON.KOTX.WW.Y.0021.210322T0000Z-210322T1800Z/ East Slopes Northern Cascades- Including the cities of Holden Village, Plain, Stevens Pass, Mazama, and Stehekin 107 PM PDT Sun Mar 21 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 5 PM THIS AFTERNOON TO 11 AM PDT MONDAY FOR THE CASCADE CREST INCLUDING HIGHWAY 2 BETWEEN COLES CORNER AND STEVENS PASS... * WHAT...Snow expected for the Cascade Crest including Highway 2 between Coles Corner and Stevens Pass. Total snow accumulations up to 9 inches. * WHERE...Holden Village, Plain, Stevens Pass, Mazama, and Stehekin. * WHEN...From 5 PM this afternoon to 11 AM PDT Monday. * IMPACTS...Travel could be very difficult across Stevens Pass. Roads, and especially bridges and overpasses, will likely become slick and hazardous. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ SB
709 WWUS46 KOTX 220729 WSWOTX URGENT - WINTER WEATHER MESSAGE National Weather Service Spokane WA 1229 AM PDT Mon Mar 22 2021 IDZ004-221800- /O.CON.KOTX.WW.Y.0021.000000T0000Z-210322T1800Z/ Central Panhandle Mountains- Including the cities of Fourth Of July Pass, Wallace, Osburn, Dobson Pass, Kellogg, St. Maries, Mullan, and Pinehurst 1229 AM PDT Mon Mar 22 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM PDT THIS MORNING... * WHAT...Snow expected. Total snow accumulations between 4 to 7 inches in the mountains and 1 to 3 inches in the valleys. * WHERE...Fourth Of July Pass, Wallace, Osburn, Dobson Pass, Kellogg, St. Maries, Mullan, and Pinehurst. * WHEN...Until 11 AM PDT this morning. * IMPACTS...Be prepared for wintry travel, especially across Lookout Pass. Slushy wet snow accumulations will be possible in the valleys. 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. && $$ WAZ042-221800- /O.CON.KOTX.WW.Y.0021.000000T0000Z-210322T1800Z/ East Slopes Northern Cascades- Including the cities of Holden Village, Plain, Stevens Pass, Mazama, and Stehekin 1229 AM PDT Mon Mar 22 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM PDT THIS MORNING FOR THE CASCADE CREST INCLUDING HIGHWAY 2 BETWEEN COLES CORNER AND STEVENS PASS... * WHAT...Snow for the Cascade Crest including Highway 2 between Coles Corner and Stevens Pass. Additional snow accumulations 2 to 4 inches except up to 1 inch in the valleys. * WHERE...Holden Village, Plain, Stevens Pass, Mazama. * WHEN...Until 11 AM PDT this morning. * IMPACTS...Travel could be very difficult across Stevens Pass. Roads, and especially bridges and overpasses, will likely become slick and hazardous. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ JW
616 WWUS46 KOTX 221756 WSWOTX URGENT - WINTER WEATHER MESSAGE National Weather Service Spokane WA 1056 AM PDT Mon Mar 22 2021 IDZ004-WAZ042-221900- /O.EXP.KOTX.WW.Y.0021.000000T0000Z-210322T1800Z/ Central Panhandle Mountains-East Slopes Northern Cascades- Including the cities of Fourth Of July Pass, Wallace, Osburn, Plain, Dobson Pass, Holden Village, Kellogg, St. Maries, Mazama, Stehekin, Stevens Pass, Mullan, and Pinehurst 1056 AM PDT Mon Mar 22 2021 ...WINTER WEATHER ADVISORY WILL EXPIRE AT 11 AM PDT THIS MORNING... The threat has ended. $$ RP
Nearby
Winter Weather Advisories in Idaho, 2021Winter Weather Advisories in Washington, 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.