Likelihood ?CertainVery LikelyLikelyPossible
Size ?HistoricVery LargeLarge
Some weather models predicting up to 2 to 4 inches today, the temperatures at upper elevations will be around 32 degrees or slightly below accompanied by winds. I only expect to see the accumulations at upper elevations which is where the hazard will be. If the accumulations are on the high side, the new storm slabs could become touchy as they may be dense and could slide on older lighter snow that is in the upper snowpack. It should be easy to do some quick hand shear tests or use the sled to cut blocks in the upper pack to observe the stability as you travel around. Slopes greater than 35 in upper elevations could be enough steepness to get things moving. With precipitation and temperatures right on the tipping point of being favorable or non favorable it's very much up to all of us to decide when it's safe to hit a slope. Always remember any rapid change is no good for stability.
National Weather Service Spokane WA
351 AM PST Fri Jan 24 2020
A mild and active weather pattern is expected into next week
with several rounds of mainly valley rain and mountain snow.
Today through Sunday: The mild and wet pattern continues with a
series of waves tracking into the region from the southwest.
Today: The first system in the form of an occluded front will
track across Eastern Washington and North Idaho this morning
bringing widespread rain and high mountain snow. Behind it
westerly flow will lead to a drying trend over Central WA by early
morning and across much of Eastern WA late morning or early
afternoon while showers will be more prevalent in the Cascades and
Idaho Panhandle. Breezy winds across the Columbia Basin behind
the front combined with mild 850mb temperatures around 2C should
translate to mild temperatures in the mid 40s to low 50s for
Tonight and Saturday: A mid level wave passing through tonight will
keep showers persisting across the ID Panhandle and Cascades with
snow levels dropping to around 3000 feet. Light accumulations are
possible in the mountains. On Saturday yet another wave reaches
Central WA in the morning and then NE WA/N Idaho late morning into
the afternoon. Precip amounts are light, but could lead to a
rain/snow mix northern valleys and Cascade valleys and valley
rain/mountain snow elsewhere.
Saturday night and Sunday: A stronger system arrives as a surface
low deepens to around 995mb as it tracks north near or just off
the WA coast. This is expected to bring widespread precipitation
into the region especially overnight Saturday night into Sunday
morning with snow levels ranging from 3000-5000 feet for most of
the area resulting in valley rain and mountain snow. Snow levels
could begin lower however along the East Slopes of the Cascades.
In addition an easterly pressure gradient over the area will
provide increased isentropic ascent and precipitation amounts for
the Cascades. Moderate snow accumulations of 6 to 10 inches are
likely in the mountains. Snow amounts around Winthrop, Stehekin,
and Lake Wenatchee are a tougher call as surface temperatures may
have a hard time dropping down to freezing Saturday night before
precipitation arrives due to abundant boundary layer moisture and
stratus limiting temperature falls. Most model guidance suggest
the Methow Valley will be cold enough for snow, with a rain/snow
mix more likely for the Leavenworth and Lake Wenatchee areas. Wet
snow may also occur on the Waterville Plateau and near the
Canadian border before snow levels rise. Accumulations in these
areas should be light. As the low weakens and tracks into British
Columbia on Sunday mild southwest winds again develop across the
Columbia Basin, Spokane area, Palouse, and LC Valley with highs
again very mild in the mid 40s to near 50. JW
Sunday night through Friday: Subtle change in the overall weather
pattern for the start of next week. Instead of weather systems
coming at us from the southwest, they will be more from the west.
Thus they will be a little cooler, for a little better chance of
low-elevation snow, mainly in the late night and morning hours.
Not looking for anything appreciable even if it does occur.
Looks like there might be a brief break in the precipitation
around Tuesday night or Wednesday. But another even warmer system
moves in around Thursday. Snow levels in the Panhandle rise to
about 5000 feet.
The cold front that comes through the region on Thursday night and
Friday could be a windy one. Not much computer model agreement on
it at this point, but some ensemble members show the potential for
a high wind event. Too far out in the forecast to get into
details, but it will bear watching. RJ
Yesterday light snow accumulations were happening at upper elevations only with rain level at 5000' elevation in the Selkirks. I observed a few inches of new wet and heavy snow at 6100 feet that became sticky at 4500 feet. Total snowpack was 10 feet and very consolidated. There were some weaknesses 6 inches down and 1.5 feet deep in the pack that appeared to be due to snow density change and the new load of wet heavy snow atop those layers. That is my primary concern for today with up to 8 inches of snow coming throughout the day. We also had observations submitted by a private party from Lunch Peak at 6280 reporting 11 feet of snow and 3 moderate failures in the upper 2 feet of snowpack on the storm snow interfaces.
Temperatures decreasing to 27 with 2 to 4 inches with breezy conditions today. Temperatures expected to stay below 32 through weekend.
|0600 temperature:||31 deg. F.|
|Max. temperature in the last 24 hours:||35 deg. F.|
|Average wind direction during the last 24 hours:||250|
|Average wind speed during the last 24 hours:||10 mph|
|Maximum wind gust in the last 24 hours:||35 mph|
|New snowfall in the last 24 hours:||2 inches|
|Total snow depth:||115 inches|
Avalanche conditions change for better or worse continually. Backcountry travelers should be prepared to assess current conditions for themselves, plan their routes of travel accordingly, and never travel alone. Backcountry travelers can reduce their exposure to avalanche hazards by utilizing timbered trails and ridge routes and by avoiding open and exposed terrain with slope angles of 30 degrees or more. Backcountry travelers should carry the necessary avalanche rescue equipment such as a shovel, avalanche probe or probe ski poles, a rescue beacon and a well-equipped first aid kit. For a recorded version of the Avalanche Advisory call (208)765-7323.
This website is owned and maintained by the Friends of the Idaho Panhandle Avalanche Center. Some of the content is updated by the USDA avalanche forecasters including the forecasts and some observational data. The USDA is not responsible for any advertising, fund-raising events/information, or sponsorship information, or other content not related to the forecasts and the data pertaining to the forecasts.