Heavy snow amounts fell above 7 thousand feet.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS PIH wrote it up.
Heavy snow amounts fell above 7 thousand feet.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Pocatello, ID wrote its last area forecast discussion before the first event at Dec 18, 2:00 AM MST, 2 hours earlier.
Area Forecast Discussion National Weather Service Pocatello ID 200 AM MST Tue Dec 18 2018 .SHORT TERM...Today through Thursday. A moist zonal flow is in place over the PAC NW this morning. Moisture is being ushered in by a 160+ kt speed max in the upper levels. The main impacts will be along Hwy 75 from Hailey to Stanley, in the Island Park area, and the Big Hole Mountains along the Wyoming border. Snow amounts will be around 4 to 6 inches at the mountain passes with about 1 to 3 inches in the valleys. Strong surface winds will likely cause blowing and drifting snow. Models are suggesting a cold front passing through the area late tonight. Winds will be particularly strong around the front, but snowfall should diminish shortly after the front passes. A rain/snow mix can be expected in the Snake Plain today with little snow accumulation. Weak ridging begins to move into the area Wednesday afternoon/evening which should help clear out the precipitation. Temperatures should remain above climatological normal in the short term periods. Hinsberger .LONG TERM...Thursday night through Tuesday. A quick moving but somewhat weak system will move through the region on Thursday night and Friday. This system will produce some light snow for the high country and perhaps some light snow for the valleys depending on how much moisture remains in tact as it moves into the Great Basin. Our next stronger system arrives possibly as early as Sunday. Models are beginning to indicate that this system could split with part of the energy dropping into the southern Great Basin. Potentially this would significantly limit snow totals across the region. Confidence remains low at this time for this system as the models just don't seem to have a good handle on it quite yet. Valle && .AVIATION...Another storm system will arrive today. This system will produce gusty conditions for this afternoon and tonight. DIJ and possibly SUN have the best chances for ifr ceilings and visibilities from snow this afternoon and evening, although other locations could see lower ceilings and visibilities as well. Valle && .PIH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 5 AM early this morning to 11 AM MST Wednesday for IDZ064-066-072-073. &&
The national radar mosaic for the moment the first event began.
2 heavy snow. Local standard time, as filed.
The Vienna Mine SNOTEL recorded 15 inches of snow.
Heavy snow amounts at high elevations SNOTEL sites were: 10 inches at Dollarhide Summit, 9 inches at Galena, 11 inches at Galena Summit, 6 inches at Hyndman, and 10 inches at Lost Wood Divide.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2018Every state in 2018This day in weather historyWarnings in Idaho, December 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 798850, 798851.