THIS AVALANCHE ADVISORY EXPIRED ON March 26, 2019 @ 6:44 am
Avalanche Advisory published on March 25, 2019 @ 6:44 am
Issued by George Halcom - Payette Avalanche Center
bottom line

The Avalanche Hazard is Low today. Loose wet avalanches are possible as the snow pack receives sunlight, and daytime temperatures warm up. Avoid steep, rocky slopes that are getting the direct influence of the sun.  Later in the day, South winds around 30 MPH will be transporting snow and forming shallow wind slabs.

How to read the advisory


  • Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1: Loose Wet
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Temperatures will rise through the day.  The upper elevations are forecasted to climb back up into the upper 30's. Along with the warm daytime temps, the cloud filtered Sun will heat up the new snow surface making small, loose wet avalanches possible. Avoid steep, rocky slopes that are getting the direct influence of the sun.  Choose slopes that are cooler, and are not getting heated up by the Sun.

 

 

 

Avalanche Problem 2: Wind Slab
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South winds are forecasted to ramp into the 30 MPH range today as a storm system approaches the West Central Mountains. Shallow wind slabs from 2-6 inches in depth are possible in upper elevation wind loaded, and cross-loaded terrain.

 

advisory discussion

PAC will issue 3 Advisories per week through April 5. 

Your Observations are extremely helpful and appreciated by all backcountry users.  If you have not checked our our Observations page, it is really easy to add snow or avalanche info.  Drop down menus and prompts will lead you through it and it is easy to add photos.

Please be aware that there are areas that are CLOSED to motorized traffic in the McCall, Goose Lake and greater West Mountains area.  Just because there are tracks in some areas, does not mean they are open.  Please respect all users and closures.  See the Payette Winter Travel Maps for clarification.  Both the East and West maps can be downloaded on the Avenza app on your phone or are available at trailheads and local shops.   IT IS YOUR RESPONSIBILITY TO KNOW WHERE YOU ARE AND WHERE THESE CLOSURES EXIST. 

CURRENT CONDITIONS Today's Weather Observations From the Granite Weather Station at 7700 ft.:
0600 temperature: 21 deg. F.
Max. temperature in the last 24 hours: 28 deg. F.
Average wind direction during the last 24 hours: W
Average wind speed during the last 24 hours: 20 mph
Maximum wind gust in the last 24 hours: 20 mph
New snowfall in the last 24 hours: NA inches
Total snow depth: NA inches
weather

 

Area Forecast Discussion
National Weather Service Boise ID
257 AM MDT Mon Mar 25 2019

.SHORT TERM...Today through Thursday...Brief upper level ridging
will keep us precipitation-free most of today, but that will
change rapidly tonight as southwest flow aloft increases and a
large trough off the coast moves inland. Precipitation will enter
eastern Oregon late this afternoon and this evening. The system
will spread into much of southwest Idaho late tonight, with the
best chance in the West-Central Mountains. Tuesday, models differ
on the coverage of precipitation, with the GFS the wettest, and
the EC the driest. We have leaned toward the wetter models as
precipitable water and moisture transport values are impressive,
and instability increases slightly as well. Tue night and Wed the
chance of precipitation increases yet again, as a positively-
tilted shortwave swings inland across northern CA and toward our
CWA. This will further destabilize the atmosphere and increase
advection of heat and moisture. Wed night and Thu things stay
pretty wet as the upper low slowly moves closer and we remain in
an area of continued lift and instability. Snow levels will range
from 5000 to 6000 feet for much of the short term period, with all
accumulating snows confined to elevations above 5000 feet.

Winds will be notable this afternoon in the Upper Treasure Valley
near Mountain Home, with gusts to near 40 mph possible. At this
point the forecast is just below wind advisory criteria, but
please be aware that southeast winds will increase through the day
over much of the Upper Treasure Valley. Temps will warm
considerably today, with readings in the lower to mid 60s
expected in lower elevations. As the precipitation increases Tue
through Thu, temps will remain in the 50s each day. Lows will
range from 40 to 45 in the lower elevations through the short term
period.

.LONG TERM...Thursday night through Sunday...Upper level trough
passage will bring showers through Friday afternoon. Showers will
increase in coverage Friday afternoon with better instability.
Snow levels will remain between 4000-5000 ft MSL. Upper level
ridge builds in beginning Saturday ahead of the next upper level
trough. Snow levels rise along with temperatures. The next trough
reaches the region late Sunday/Monday bringing more precipitation.
The timing of this system varies quite a bit between the models
so confidence remains low. Temperatures will remain above normal
through the period.

&&

.AVIATION...Mostly VFR. Patchy fog developing in sheltered
valleys this morning should dissipate by 18z. Otherwise, mostly
clear skies today. Surface winds: east-southeast less than 10 kts
increasing to 15-25 kts through the Snake River Valley after 18z.
Winds aloft at 10k feet MSL southwest 10-20 kts becoming south
30-40 kts after 18z.

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Monday Monday Night Tuesday
Weather: Patchy fog before noon. Otherwise, mostly sunny, with a high near 50. Calm wind becoming south 5 to 8 mph in the afternoon. Showers likely after midnight. Mostly cloudy, with a low around 32. South wind 5 to 9 mph becoming calm after midnight. Winds could gust as high as 20 mph. Chance of precipitation is 70%. Showers. High near 41. Calm wind becoming south southwest around 5 mph in the afternoon. Chance of precipitation is 80%.
Temperatures: 50 deg. F. 27 deg. F. 41 deg. F.
Wind direction: S S SSW
Wind speed: 5-8 5-9, Gusts 20 MPH 5
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Monday Monday Night Tuesday
Weather: Mostly sunny, with a high near 38. South southeast wind 8 to 16 mph, with gusts as high as 30 mph. Snow showers after midnight. Low around 27. South wind 13 to 18 mph, with gusts as high as 30 mph. Chance of precipitation is 80%. New snow accumulation of around an inch possible. Snow showers. High near 30. South southwest wind 10 to 13 mph. Chance of precipitation is 90%. New snow accumulation of 1 to 3 inches possible.
Temperatures: 38 deg. F. 27 deg. F. 30 deg. F.
Wind direction: SSE S SSW
Wind speed: 8-16, Gusts 30MPH 13-18, Gusts 30 MPH 10-13 MPH
Expected snowfall: 0 in. 1 in. 1-3 in.
Disclaimer

This avalanche advisory is provided through a partnership between the Payette National Forest and the Payette Avalanche Center. This advisory covers the West Central Mountains between Hard Butte on the north and Council Mountain on the south. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires at midnight on the posted day unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.