A pair of weather disturbances, the first one quickly passing through the region on the evening of February 23rd and through the 24th and the second stronger system transiting the region during the day of February 25th brought heavy mountain snow to the high terrain of the central Idaho panhandle and moderate to locally heavy snow to the Idaho Palouse region, the Coeur D'Alene area and the…
Every event with a place to put it; 12 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 pair of weather disturbances, the first one quickly passing through the region on the evening of February 23rd and through the 24th and the second stronger system transiting the region during the day of February 25th brought heavy mountain snow to the high terrain of the central Idaho panhandle and moderate to locally heavy snow to the Idaho Palouse region, the Coeur D'Alene area and the valleys of the central panhandle.
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 Feb 23, 3:58 PM PST, 2 hours 2 minutes earlier.
Area Forecast Discussion
National Weather Service Spokane WA
358 PM PST Fri Feb 23 2018
.SYNOPSIS...
A series of storm systems will impact the Inland Northwest this
weekend into early next week with the potential for more snow,
breezy conditions and continued below normal temperatures for most
locations. The first round of snow will arrive over most of the
Inland Northwest this evening and continue at times through
Saturday. Another system will move into the region on Sunday.
&&
.DISCUSSION...
...Light to moderate snow tonight into Saturday. Snow and wind
Sunday...
Tonight through Sunday: This weekend will feature a pair of storm
systems. The first arrives this evening and lingers into
Saturday. A second system impacts the area Sunday. The general
storm track will be from the northwest which favors the the Idaho
Panhandle and Cascade Crest to receive the heaviest snow however
portions of the Blue Mountains and Palouse can also expect a
healthy dosage as well.
As of 2PM...a cold front and band of light snow was moving across
Central WA. This band will continue to march east toward the
Idaho Panhandle arriving close to rush hour and lingering into the
evening hours. Snowfall amounts will be extremely light in the
lee of the Cascades and Western Basin increasing around an inch or
two toward the Idaho Panhandle. Timing of this band into Eastern
WA and N ID could lead to slick conditions during the Friday
evening commute. A trailing cold core shortwave will track into
the region tonight. All models agree on weak surface low
developing with this wave and tracking west to east between
Highway 2 and I-90 across the Columbia Basin. Rapid cooling aloft
coupled with lift along the low will result in increasing snow
across much of the Idaho Panhandle and eastern reaches of WA with
a favorable setup for heavier snow bands. Snow intensities under
some of these bands may become moderate to heavy at times and
result in quick accumulations of 1-2 inches. Winds will become
breezy south and east of the surface low. Southwest winds of 10-20
mph with gusts near 25 mph will impact portions of Southeastern
WA and the lower Idaho Panhandle and could lead to patchy drifting
snow. Thinking the Camas Prairie may have the greatest threat
because of the additional 2-4 inches of fluffy snow that fell last
night. Snow from this first system will wane Saturday afternoon
with a brief break Saturday evening but a second round of snow and
winds arrives Saturday night into Sunday.
A second, deeper shortwave drops into the Northwestern US Saturday
night into Sunday. This is a much more dynamic system featuring a
stronger surface low across southwestern Canada and much tighter
packing of pressure gradients across the CWA. This equates to more
wind and much stronger orographic lift into the Cascades and into
the rising terrain of North Idaho, especially the Central
Panhandle Mountains. Precipitation will start off light Saturday
night with the passage of a warm front then look for snow to
increase early Sunday morning between 0400-1000 PST and continue
into the early afternoon. Snow amounts in excess of a foot are
expected for the mountains of southern Shoshone County and along
the Cascade Crest near Stevens Pass. Moderate to heavy amounts on
the order of 4-8 inches will also be possible in the rising
terrain of the Palouse, Camas Prairie, Blue Mountains, and into
the Silver Valley. Lighter amounts are expected northward and into
NE WA including the Spokane Area.
As for winds, we have increased winds for the Eastern Columbia Basin
including the Palouse and foothills of the Blue Mountains. Winds
will increase in these areas Saturday night into early Sunday
morning with speeds near sunrise on the order of 20-30 mph. Wind
gusts of 30-45 mph are expected but potential gusts of 50 mph are
not out of the question. This is because we see 50kts around
1500-2K ft AGL. Hi-res model data suggest this low-level jet will
remain decoupled from the surface Sunday morning and then weaken
closer to 40-45kts by the afternoon when gusts will have a better
potential to mix down to the surface but this will need to be
monitored closely. Exposed ridgetops will stand a better shot of
experiencing wind gusts in the 40-60 mph range. For the remainder
of the Columbia basin including the Waterville Plateau, expect
winds on the order of 15-25 mph with gusts closer to the 30-35 mph
range. /sb
Sunday night through Friday...Through the extended period it looks
like the pattern remains fairly progressive in northwest flow.
One upper low will exit the region on Monday, a second will drop
through the region Tuesday/Tuesday night, and a third will drop in
Thursday and Friday. There are some changes however, as the
models are indicating that the ridge that has been lingering out
near 160W will slowly begin to retrograde to the west. This in
turn will allow the storm systems to drop south along or even west
of the coast. This would keep the weather unsettled, but allow
temperatures to slowly creep back up to around normal by the end
of the week.
Sunday night and Monday...As mentioned above a deep and cold low
will track south on Sunday and exit the region Sunday night. The
focus of the precipitation will shift to the Cascade crest, The
Panhandle mountains, and south towards the Blue mountains and the
Camas Prairie. 5-6 inches of new snow will be possible in the
mountains above Clarkia and Avery, with a couple of inches of snow
for the Blues and up near Winchester by the end of the day
Monday. Strong gusty winds behind an exiting cold font will result
in wind gust 20 to 30 mph to continue through the night for the
Basin, the Waterville Plateau, the Palouse, and on ridge tops
through about midnight. Temperatures will remain on the cool side
of normal.
Monday night through Wednesday...After a brief break in the weather
Monday night the next low will take a similar track, with similar
results as the one this weekend. The lower east slopes and the
western basin will be mostly missed, but the Cascades and the
eastern half of the forecast area will have another chance to pick
widespread precipitation. Again it will be cold enough to support
mainly snow, with a rain/snow mix for a portions of the eastern
Basin south of highway 21. Northerly flow will keep temperatures
on the cool side of normal.
Thursday and Friday...This is out pretty far in the forecast but
we could see temperatures begin to warm to around normal by the
weekend. Model guidance is showing the next storm system tracking
south along the coast Thursday night before ejecting back to the
northeast Friday night and Saturday. This will allow the flow to
shift to the southwest and result in warming temperatures with a
much deeper Pacific moisture tap. This will keep the unsettled
weather in the forecast through the extended period. Tobin
&&
.AVIATION...
00Z TAFS: A cold front is moving through the area at the time and
will bring a band of light to moderate snow to the eastern TAF
sites 00-03z. When the front moved through KMWH vis dropped to
1/2sm sn for an hour. The same is possible for KCOE-KGEG-KSFF-
KPUW. Snow will taper off to isolated -shsn through 10-11z with
cig/vis returning to VFR/MVFR. A surface low will come through the
region early Saturday morning and will result in bands of
moderate to locally heavy snow from 10-11z through 18-19z. This
will likely drop conditions back down to IFR at times. Then
returning back to VFR conditions with clearing from the west after
18z. Tobin
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 23 33 27 39 21 35 / 90 80 20 60 20 10
Coeur d'Alene 22 33 24 38 20 35 / 90 90 40 90 20 20
Pullman 23 34 27 38 23 34 / 80 90 40 90 50 20
Lewiston 31 40 33 45 27 41 / 50 80 20 60 50 20
Colville 21 35 25 40 17 37 / 80 50 20 70 20 10
Sandpoint 21 33 25 37 21 34 / 90 70 40 90 30 20
Kellogg 20 31 24 33 22 31 / 90 100 60 100 60 40
Moses Lake 26 41 32 48 23 44 / 10 20 10 20 10 0
Wenatchee 25 39 33 44 23 43 / 20 30 30 60 20 0
Omak 19 35 25 41 17 38 / 30 30 20 20 10 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 4 PM PST Saturday for Lewis and
Southern Nez Perce Counties-Lewiston Area.
Winter Weather Advisory until 1 PM PST Saturday for Coeur
d'Alene Area-Idaho Palouse.
Winter Weather Advisory until 4 PM PST Saturday for Central
Panhandle Mountains-Northern Panhandle.
WA...Winter Weather Advisory until 4 PM PST Saturday for Lower
Garfield and Asotin Counties.
Winter Weather Advisory until 1 PM PST Saturday for Spokane Area-
Washington Palouse.
Winter Weather Advisory until 4 PM PST Saturday for Northeast
Blue Mountains.
Winter Weather Advisory until 1 PM PST Saturday for Northeast
Mountains.
&&Hazardous Weather Outlook...CORRECTED National Weather Service Spokane WA 645 AM PST Fri Feb 23 2018 IDZ001>004-026-027-WAZ031>033-036-037-042-241415- Northern Panhandle-Coeur d'Alene Area-Idaho Palouse- Central Panhandle Mountains-Lewiston Area- Lewis and Southern Nez Perce Counties-Northeast Blue Mountains- Lower Garfield and Asotin Counties-Washington Palouse- Spokane Area-Northeast Mountains-East Slopes Northern Cascades- 645 AM PST Fri Feb 23 2018 This Hazardous Weather Outlook is for portions of North Idaho... North Central Idaho...North Central Washington...Northeast Washington and Southeast Washington. .DAY ONE...TODAY AND TONIGHT A winter storm will bring widespread light to moderate snow to the area beginning in the Cascades by early afternoon and across the remainder of the area by late afternoon or evening. Snow will persist at times through the night. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY Widespread snow showers will continue through Saturday morning and into the afternoon. Moderate snow amounts are possible, especially near the Cascade Crest and the Idaho Panhandle. Another potent winter weather system is expected to deliver moderate snow amounts to the Cascades and Idaho Panhandle on Sunday. This system will also be accompanied by strong and gusty winds, especially over the Palouse, southeast Washington, north-central Idaho, and in the Spokane-Coeur d'Alene area. Colder than normal temperatures and unsettled conditions will result in more snow possibilities through the week. WAZ034-035-038-041-043-044-241415- Moses Lake Area-Upper Columbia Basin-Okanogan Highlands- Wenatchee Area-Okanogan Valley-Waterville Plateau- 645 AM PST Fri Feb 23 2018 This Hazardous Weather Outlook is for portions of Central Washington...East Central Washington and North Central Washington. .DAY ONE...TODAY AND TONIGHT No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY No hazardous weather is expected at this time.
The national radar mosaic for the moment the first event began.
12 heavy snow. Local standard time, as filed.
An observer 6 miles south of Coeur D'Alene reported 8.8 inches of new snow accumulation.
An observer in Coeur D'Alene reported 7.0 inches of new snow accumulation.
An observer near Rathdrum reported 6.5 inches of new snow accumulation.
An observer near Wolf Lodge reported 4.5 inches of new snow accumulation.
An observer at Kellogg reported 4.8 inches of new snow accumulation.
An observer at Mullan reported a two day storm total of 12.7 inches of new snow accumulation.
An observer near Pritchard reported a two day storm total of 13.4 inches of new snow accumulation.
The Lookout Pass ski resort reported a two day total of 41 inches of new snow from this pair of winter storms.
The Silver Mountain ski resort reported a two day total of 32 inches of new snow from this pair of winter storms.
An observer at Moscow reported 6.5 inches of new snow accumulation.
An observer near Potlatch reported 4.0 inches of new snow accumulation.
An observer at Avery reported a two day storm total of 13.5 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, February 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: 737043, 737044, 737045, 737047, 737027, 737029, 737040, 735796, 735797, 737028, 737038, 735798.