A moist warm front developed over north Idaho during the day of December 11th followed by a cold front during the evening. The valleys of far north Idaho received heavy wet snow accumulations which turned over to rain late in the day.
Every event with a place to put it; 9 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 OTX wrote it up.
A moist warm front developed over north Idaho during the day of December 11th followed by a cold front during the evening. The valleys of far north Idaho received heavy wet snow accumulations which turned over to rain late in the day. South of Sandpoint valleys received generally light to moderate amounts of wet snow which turned to rain in the afternoon. The mountains of the entire north Idaho panhandle received all snow which accumulated to heavy amounts especially after the trailing cold front passage during the evening of December 11th when winds became favorable for persistent upslope snow showers.
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 Spokane, WA wrote its last area forecast discussion before the first event at Dec 11, 4:23 AM PST, 4 hours 37 minutes earlier.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html><!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html>The national radar mosaic for the moment the first event began.
9 heavy snow. Local standard time, as filed.
The Lookout Pass ski resort reported 23 inches of snow accumulation from this storm. The nearby Silver Mountain Ski resort reported 16 inches of new snow.
An observer at Fernwood recorded 4.0 inches of new snow accumulation from this storm.
The Scweitzer Mountain ski resort reported 11.0 inches of new snow from this storm.
The Hidden lake SNOTEL site 14 miles southwest of Porthill at 5040 ft. elevation recorded 13.0 inches of new snow from this storm system.
The Bear Mountain SNOTEL site 11 miles east of Hope recorded 12.0 inches of new snow from this storm system.
An observer 9 miles southeast of Elmira reported 7.5 inches of snow accumulation from this storm.
An observer 4 miles east of Laclede reported 5.0 inches of snow accumulation from this storm.
A member of the public near Coolin reported 5.0 inches of new snow accumulation from this storm.
A member of the public 9 miles north of Sandpoint reported 9.0 inches of new snow accumulation from this storm.
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 2026-09-30. Each event’s entry at NCEI: 792123, 792128, 792117, 792118, 792119, 792120, 792121, 792122, 792162.