Alert archive / Idaho / Winter Storm Warnings in 2021
Winter Storm Warning 6, NWS Missoula, MT
NWS Missoula, MT issued this winter storm warning at Feb 18, 2021, 9:23 AM PST for Clearwater County, Idaho County, Idaho. It took effect at Feb 18, 2021, 4:00 PM PST. It was in force for 16 hr. 3 reports came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Feb 18, 2021, 9:23 AM PST (17:23 UTC)
- In effect from
- Feb 18, 2021, 4:00 PM PST
- Expired
- Feb 19, 2021, 8:00 AM PST
- In force
- 16 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 17:23 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Feb 19, 7:00 AM PST | SNOW 4.6 | 1 Wsw Ahsahka, ID | COCORAHS STATION ID-CW-6 AHSAHKA. |
| Feb 19, 7:30 AM PST | SNOW 3.6 | 10 Sse Orogrande, ID | CO-OP OBSERVER STATION DXEI1 DIXIE 1 N. |
| Feb 19, 8:00 AM PST | SNOW 2.1 | 1 E Woodland, ID | COCORAHS STATION ID-ID-5 WOODLAND. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Spokane, WA (KOTX), launched 12:00Z, 5.4 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
- 1310 m above ground
- 0-6 km bulk shear
- 57 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 76 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
635 WWUS45 KMSO 181723 WSWMSO URGENT - WINTER WEATHER MESSAGE National Weather Service Missoula MT 1023 AM MST Thu Feb 18 2021 IDZ007-191600- /O.UPG.KMSO.WS.A.0004.210218T2100Z-210219T1200Z/ /O.NEW.KMSO.WS.W.0006.210219T0000Z-210219T1600Z/ Orofino/Grangeville Region- 923 AM PST Thu Feb 18 2021 ...WINTER STORM WARNING IN EFFECT FROM 4 PM THIS AFTERNOON TO 8 AM PST FRIDAY... * WHAT...Heavy snow and blowing snow expected. Gusty winds up to 50 mph will cause widespread blowing and drifting of snow and whiteout conditions in Grangeville and vicinity. Total snow accumulations of 1 to 3 inches possible. * WHERE...The Camas Prairie, including Grangeville. * WHEN...From 4 PM this afternoon to 8 AM PST Friday. * IMPACTS...Travel could be very difficult to impossible. Snow drifts may completely block roadways. PRECAUTIONARY/PREPAREDNESS ACTIONS... If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ MTZ004-191900- /O.CON.KMSO.WW.Y.0020.210219T0300Z-210220T0000Z/ Lower Clark Fork Region- 1023 AM MST Thu Feb 18 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 8 PM THIS EVENING TO 5 PM MST FRIDAY... * WHAT...Snow expected. 5 to 8 inches for Lookout Pass. Total snow accumulations of 1 to 3 inches in the valleys. * WHERE...Evaro Hill, Highway 200 Thompson Falls to Plains, Highway 200 Trout Creek to Heron, and I-90 Lookout Pass to Alberton. * WHEN...From 8 PM this evening to 5 PM MST Friday. * IMPACTS...Travel could be affected. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ IDZ005-006-191900- /O.CON.KMSO.WW.Y.0020.210219T0300Z-210220T0000Z/ Northern Clearwater Mountains-Southern Clearwater Mountains- 923 AM PST Thu Feb 18 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 7 PM THIS EVENING TO 4 PM PST FRIDAY... * WHAT...Snow expected. Total snow accumulations of 5 to 8 inches. Slightly lower amounts for Dixie and Elk City with 2 to 4 inches. * WHERE...Elk River, Highway 11 Pierce to Headquarters, Pierce, Dixie, Elk City, and Highway 12 Lowell to Lolo Pass. * WHEN...From 7 PM this evening to 4 PM PST Friday. * IMPACTS...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. && $$
3 follow-up statements
142 WWUS45 KMSO 191059 WSWMSO URGENT - WINTER WEATHER MESSAGE National Weather Service Missoula MT 359 AM MST Fri Feb 19 2021 IDZ007-191600- /O.CON.KMSO.WS.W.0006.000000T0000Z-210219T1600Z/ Orofino/Grangeville Region- 259 AM PST Fri Feb 19 2021 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 8 AM PST THIS MORNING... * WHAT...Heavy snow and blowing snow expected. Gusty winds of 35 to 45 mph will cause widespread blowing and drifting of snow and possible whiteout conditions in Grangeville and vicinity. Winds will gradually decrease through the morning hours. Total snow accumulations of 1 to 3 inches possible. * WHERE...The Camas Prairie, including Grangeville. * WHEN...Through 8 AM PST this morning. * IMPACTS...Travel could be very difficult to impossible. Snow drifts may completely block roadways. PRECAUTIONARY/PREPAREDNESS ACTIONS... If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ MTZ003-191800- /O.EXB.KMSO.WW.Y.0020.000000T0000Z-210219T1800Z/ Flathead/Mission Valleys- 359 AM MST Fri Feb 19 2021 ...WINTER WEATHER ADVISORY IN EFFECT UNTIL 11 AM MST THIS MORNING... * WHAT...Snow. Additional snow accumulations of up to one inch. Slick roads are expected for the morning commute. * WHERE...Flathead Lake, Flathead Valley, Mission Valley, and Polson. * WHEN...Until 11 AM MST this morning. * IMPACTS...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. && $$ MTZ004-200000- /O.CON.KMSO.WW.Y.0020.000000T0000Z-210220T0000Z/ Lower Clark Fork Region- 359 AM MST Fri Feb 19 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 PM MST THIS AFTERNOON... * WHAT...Snow expected. 5 to 8 inches for Lookout Pass. Total snow accumulations of 1 to 3 inches in the valleys. * WHERE...Evaro Hill, Highway 200 Thompson Falls to Plains, Highway 200 Trout Creek to Heron, and I-90 Lookout Pass to Alberton. * WHEN...Through 5 PM MST this afternoon. * IMPACTS...Travel could be affected. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ IDZ005-006-200000- /O.CON.KMSO.WW.Y.0020.000000T0000Z-210220T0000Z/ Northern Clearwater Mountains-Southern Clearwater Mountains- 259 AM PST Fri Feb 19 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 PM PST THIS AFTERNOON... * WHAT...Snow expected. Total snow accumulations of 5 to 8 inches. Slightly lower amounts for Dixie and Elk City with 2 to 4 inches. * WHERE...Elk River, Highway 11 Pierce to Headquarters, Pierce, Dixie, Elk City, and Highway 12 Lowell to Lolo Pass. * WHEN...Through 4 PM PST this afternoon. * IMPACTS...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. && $$
667 WWUS45 KMSO 191220 WSWMSO URGENT - WINTER WEATHER MESSAGE National Weather Service Missoula MT 520 AM MST Fri Feb 19 2021 IDZ007-191600- /O.CON.KMSO.WS.W.0006.000000T0000Z-210219T1600Z/ Orofino/Grangeville Region- 420 AM PST Fri Feb 19 2021 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 8 AM PST THIS MORNING... * WHAT...Snow and blowing snow expected. Gusty winds of 35 to 45 mph will cause widespread blowing and drifting of snow and possible whiteout conditions in Grangeville and vicinity. Winds will gradually decrease through the morning hours. Total snow accumulations of 1 to 3 inches possible. * WHERE...The Camas Prairie, including Grangeville. * WHEN...Through 8 AM PST this morning. * IMPACTS...Travel could be very difficult to impossible. Snow drifts may completely block roadways. PRECAUTIONARY/PREPAREDNESS ACTIONS... If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ MTZ005-043-191800- /O.EXA.KMSO.WW.Y.0020.000000T0000Z-210219T1800Z/ Missoula/Bitterroot Valleys-Potomac/Seeley Lake Region- 520 AM MST Fri Feb 19 2021 ...WINTER WEATHER ADVISORY IN EFFECT UNTIL 11 AM MST THIS MORNING... * WHAT...Snow. Periodic snow showers will bring highly variable road conditions. Slick roads are expected for the morning commute. Additional snow accumulations of up to one inch. * WHERE...Bitterroot Valley, Missoula, Highway 200 Bonner to Greenough, Highway 83 Seeley Lake to Condon, and I-90 East Missoula to Bearmouth. * WHEN...Until 11 AM MST this morning. * IMPACTS...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. && $$ MTZ004-200000- /O.CON.KMSO.WW.Y.0020.000000T0000Z-210220T0000Z/ Lower Clark Fork Region- 520 AM MST Fri Feb 19 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 PM MST THIS AFTERNOON... * WHAT...Snow expected. 5 to 8 inches for Lookout Pass. Total snow accumulations of 1 to 3 inches in the valleys. * WHERE...Evaro Hill, Highway 200 Thompson Falls to Plains, Highway 200 Trout Creek to Heron, and I-90 Lookout Pass to Alberton. * WHEN...Through 5 PM MST this afternoon. * IMPACTS...Travel could be affected. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ IDZ005-006-200000- /O.CON.KMSO.WW.Y.0020.000000T0000Z-210220T0000Z/ Northern Clearwater Mountains-Southern Clearwater Mountains- 420 AM PST Fri Feb 19 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 PM PST THIS AFTERNOON... * WHAT...Snow expected. Total snow accumulations of 5 to 8 inches. Slightly lower amounts for Dixie and Elk City with 2 to 4 inches. * WHERE...Elk River, Highway 11 Pierce to Headquarters, Pierce, Dixie, Elk City, and Highway 12 Lowell to Lolo Pass. * WHEN...Through 4 PM PST this afternoon. * IMPACTS...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. && $$ MTZ003-191800- /O.CON.KMSO.WW.Y.0020.000000T0000Z-210219T1800Z/ Flathead/Mission Valleys- 520 AM MST Fri Feb 19 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM MST THIS MORNING... * WHAT...Snow. Additional snow accumulations of up to one inch. Slick roads are expected for the morning commute. * WHERE...Flathead Lake, Flathead Valley, Mission Valley, and Polson. * WHEN...Until 11 AM MST this morning. * IMPACTS...Travel could be affected. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$
021 WWUS45 KMSO 191539 WSWMSO URGENT - WINTER WEATHER MESSAGE National Weather Service Missoula MT 839 AM MST Fri Feb 19 2021 IDZ007-191645- /O.EXP.KMSO.WS.W.0006.000000T0000Z-210219T1600Z/ Orofino/Grangeville Region- 739 AM PST Fri Feb 19 2021 ...WINTER STORM WARNING WILL EXPIRE AT 8 AM PST THIS MORNING... Winds have decreased significantly over the area, reducing the threat of drifting snow. Additional light snow is possible over the next few hours. $$ MTZ004-200000- /O.CON.KMSO.WW.Y.0020.000000T0000Z-210220T0000Z/ Lower Clark Fork Region- 839 AM MST Fri Feb 19 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 PM MST THIS AFTERNOON... * WHAT...Snow. Additional snow accumulations of up to two inches. * WHERE...Evaro Hill, Highway 200 Thompson Falls to Plains, Highway 200 Trout Creek to Heron, and I-90 Lookout Pass to Haugan. * WHEN...Until 5 PM MST this afternoon. * IMPACTS...Travel could be affected. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ IDZ005-006-200000- /O.CON.KMSO.WW.Y.0020.000000T0000Z-210220T0000Z/ Northern Clearwater Mountains-Southern Clearwater Mountains- 739 AM PST Fri Feb 19 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 PM PST THIS AFTERNOON... * WHAT...Snow. Additional snow accumulations of 1 to 3 inches. * WHERE...Elk River, Highway 11 Pierce to Headquarters, Pierce, Dixie, Elk City, and Highway 12 Lowell to Lolo Pass. * WHEN...Until 4 PM PST this afternoon. * IMPACTS...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. && $$ MTZ003-191800- /O.CON.KMSO.WW.Y.0020.000000T0000Z-210219T1800Z/ Flathead/Mission Valleys- 839 AM MST Fri Feb 19 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM MST THIS MORNING... * WHAT...Snow. Additional snow accumulations of up to one inch. * WHERE...Flathead Lake, Flathead Valley, Mission Valley, and Polson. * WHEN...Until 11 AM MST this morning. * IMPACTS...Travel could be affected. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ MTZ005-043-191800- /O.CON.KMSO.WW.Y.0020.000000T0000Z-210219T1800Z/ Missoula/Bitterroot Valleys-Potomac/Seeley Lake Region- 839 AM MST Fri Feb 19 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM MST THIS MORNING... * WHAT...Snow. Additional snow accumulations of up to one inch. * WHERE...Bitterroot Valley, Missoula, Highway 200 Bonner to Greenough, Highway 83 Seeley Lake to Condon, and I-90 East Missoula to Bearmouth. * WHEN...Until 11 AM MST this morning. * IMPACTS...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. && $$
The office that day
Everything else NWS Missoula, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 18, 2:06 AM PST | Winter Weather Advisory | MSO | Clearwater, Idaho | 35 hr |
Nearby
Winter Storm Warnings in Idaho, 2021Every winter storm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.