A late winter storm moved across Idaho spreading heavy snow and strong winds over the West Central and Boise mountains and the Camas Prairie.
Every event with a place to put it; 3 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 BOI wrote it up.
A late winter storm moved across Idaho spreading heavy snow and strong winds over the West Central and Boise mountains and the Camas Prairie.
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 Boise, ID wrote its last area forecast discussion before the first event at Feb 28, 9:12 PM MST, 4 hours 48 minutes earlier.
Area Forecast Discussion
National Weather Service Boise ID
912 PM MST Wed Feb 28 2018
.DISCUSSION...The forecast looks to be on track this evening, so
no updates are needed at this time. Snow has begun near McCall, ID
and in parts of Eastern Oregon. Precip is still expected to spread
through the area tonight through tomorrow morning, with valley
locations changing to rain. A brisk SE wind in the Snake River
Valley will keep temperatures mild through the night and keep snow
accumulations under and inch. Shadowing from the Owyhees will also
keep snowfall light in the valley, with mountain locations
receiving significant snowfall through the next 36 hours.
All headlines look on track as well.
&&
.AVIATION...IFR in snow across southeast Oregon. VFR in the
mountains of southwest Idaho, but deteriorating to IFR in snow after
06Z. Mountains obscured after 06Z and continuing through Thursday.
Snake River Plain will see local MVFR starting 01/09Z, with
conditions improving after 18Z Thursday. Surface winds: south to
east 10 to 20 kts tonight, increasing Thursday to 15 to 25 kts with
gusts to 35 kts. Winds at 10k feet MSL: southwest 20 to 30 kts
through 01/12Z, then 30 to 40 kts.
&&
.PREV DISCUSSION...
SHORT TERM...Tonight through Friday...
Current satellite trends showing a winter storm developing off
the British Columbia Coast this afternoon and will spread snow
into Eastern Oregon this evening and into the Idaho Mountain
region Thursday morning. Along with heavy snow in mountains...strong
and gusty South to Southeast winds are expected across the entire
region starting Thursday morning. Gusts of 25 to 35 mph with
locally higher gusts are possible into the evening hours. Snow
levels are expected to briefly lift to 4000-5000 feet early Friday
morning before lowering back down to the valley floors by
sunrise. Models all in are good agreement indicating the cold
front pushes into the region Thursday night and brings periods of
heavier snowfall including the potential for blowing and drifting
snow into Idahos West Central and Boise Mountains. Snow begins to
taper off by Friday afternoon. Current hazard products that were
issued this morning remains fairly similar, but with the models
showing enhanced precip moving into the Boise mountains in more of
a southerly flow aloft, have upgraded the Winter Weather advisory
for the Boise mtns into a Winter Storm Warning.
LONG TERM...Friday night through Wednesday...
The upper level low still impacting the area through the first
part of the extended forecast period. Snow levels have dropped to
valley floors by now meaning any and all precipitation through
this time will be in the form of snow. Precipitation does however,
remain in the higher elevations. By Monday things begin to dry
out as a weak ridge begins to build from off the coast. Models
have trended more in line with timing of this ridge. Temperatures
through this period remain below normal.
Monday evening through Thursday morning...Starting off with
mostly sunny skies and milder conditions as weak, dry ridging and
southwesterly steering-level flow briefly dominate. By Wednesday
evening anticipate a transition into cloudy and windier conditions
as wetter, stronger troughing moves in behind the exiting ridge.
The influx of moisture will first enter from the southwest and
gradually spread northeastward covering the entire CWA by
Wednesday evening. Precipitation to initially drop out as all snow
with some lower lying valleys seeing mixed rain and snow by
Thursday morning. High and low temperatures around 5-8 degrees
below normal.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Warning until 11 AM MST Friday IDZ011-013-028-033.
Winter Weather Advisory until 11 AM MST Thursday IDZ029.
OR...Winter Storm Warning until 10 AM PST Friday ORZ062.
Winter Weather Advisory until 11 AM MST /10 AM PST/ Thursday
ORZ061-063.
&&
www.weather.gov/Boise
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise
DISCUSSION...EP
AVIATION.....SP
PREV SHORT TERM...CR
PREV LONG TERM....JC/WHThe national radar mosaic for the moment the first event began.
3 heavy snow. Local standard time, as filed.
Trained spotters reported 12 inches of new snow at Garden Valley and Idaho City and 16 inches at Featherville.
The COOP observer at Cambridge reported 9 inches while the Council Hydromet recorded 10 inches of snow and a trained spotter at Goodrich reported 6 inches.
The COOP observer at Fairfield reported 12 inches of snow and a trained spotter reported 21 inches.
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, March 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: 745140, 745329, 745289.