Avalanche Forecast for Saturday, February 9, 2019

This forecast was published 02/09/2019 at 7:08 AM.
A new forecast will be issued tomorrow.

NOT THE CURRENT FORECAST

This is an archived avalanche forecast and expired on 02/09/2019 at midnight.


The Bottom Line

A drop in temperature by nearly 50 degrees since yesterday is creating a hard, slick crust as our dominant snow surface. You may be able to find isolated and small pockets of wind slab from the trace of new snow overnight. That said, long sliding falls on our refrozen snow surface and brutally cold weather conditions should be of greater concern than avalanches today. Remember that the current unforgiving cold and wind quickly make small problems into big problems. All forecast areas have LOW avalanche danger.

The term Long Sliding Falls is mentioned in this forecast from time to time when a wet snow surface refreezes. The significance and danger of a small stumble on seemingly benign terrain cannot be overstated. If you have not practiced self arrest with an ice axe you should. If you have practiced, know that the effectiveness of this skill is limited in the hard icy snow you’ll encounter in the mountains this weekend. Self arrest is a last resort and may only serve to slow you down on your way to the floor of the ravine. In these conditions, very careful movement is necessary to prevent a fall from happening in the first place. Put crampons on before slopes steepen and get your ice axe out and ready before you expect to need it. Crampons and ice axes cause injuries almost as often as they prevent them, so never practice self arrest with crampons on or on a slope without a clean and flat runout.

2019-2-9_printable_pdf

 

Forecast Area

Mountain Weather

The recent warm and wet weather quickly gave way to cold with extreme winds overnight. Temperatures are below or near to 0F throughout our terrain. The current summit temperature is -11F and forecast to drop a few more degrees before rebounding slowly to single digits below 0F tonight and tomorrow. A trace of snow fell last night and snow showers this morning could produce additional though minimal accumulation before our mostly cloudy skies trend towards mostly clear. Summit wind near 100 mph since early last night should shift from W to NW today while holding at just over 100 mph with stronger gusts. Wind speeds will decrease overnight towards 60 mph by tomorrow.

Snowpack and Avalanche Discussion

Our recently wetted snowpack is mostly refrozen and will continue to gain stability as the snow deeper in the snowpack refreezes. A crust on the surface is likely to be already supportable, especially in steep terrain, though may remain breakable in the trees or at low elevations. You may be able to find very small pockets of new wind slab, but by and large, our terrain is void of an avalanche problem. Today marks the formation of another crust that will become a factor in future snowpack stability. On the east side of the range, avalanche paths are well developed and now have a widespread smooth bed surface for future avalanches.

Additional Concerns

The Sherburne and Gulf of Slides ski trails are snow covered and firm to Pinkham Notch. Just in time for these low tide riding conditions, we’ve added a “Learn” tab to our website menu. Use these quality online avalanche education resources to prep for our next round of elevated avalanche danger.

Snow Plot Information

DateHN24HN24W
(SWE)
Density (%)HSTTotalAir TT MaxT MinSkyPrecipComments
03/26/19
05:30
0 CM 0 MM0CM245 CM-16.0 C-7.0 C-16.0 CClearNo precipitation
03/25/19
05:20
3 CM 1.7 MM 9%3CM249 CM-12.0 C-2.0 C-12.0 CBrokenNo precipitation
03/24/19
05:19
0 CM 4.0 MM32CM250 CM-10.5 C-5.0 C-13.0 CClearNo precipitationView
03/23/19
05:17
38 CM 38.6 MM 12%NC253 CM-5.5 C-2.5 C-5.5 COvercastSnowView
03/22/19
05:20
Trace Trace NC213 CM-4.0 C3.0 C-4.0 COvercastSnowView

Avalanche Log and Summit Weather

Daily Observations


Thank you Mount Washington Observatory for providing daily weather data from the summit of Mount Washington.

DateMax TempMin TempTotal (SWE)24H Snow & IceWind AvgWind Fastest MileFastest Mile DirAvalanche Activity
03/25/1911 F-3 F .15 in 1.7 in56.5 MPH86 MPH

270 (W)

03/24/1914 F1 F .21 in 3.4 in74 MPH123 MPH

310 (NW)

03/24/1918 F4 F Trace in 0.1 in63.2 MPH98 MPH

290 (WNW)

03/23/1914 F1 F 0.21 in 3.4 in74.4 MPH123 MPH

310 (NW)

03/22/1924 F12 F 1.09 in 15.2 in38.9 MPH79 MPH

330 (NNW)

View
03/21/1926 F15 F 0.02 in 0.3 in28.8 MPH60 MPH

160 (SSE)

03/20/1917 F1 F 0.0 in 0.0 in32 MPH58 MPH

270 (W)

03/19/194 F-4 FTrace Trace 43.4 MPH63 MPH

300 (WNW)

03/18/193 F-6 F 0.03 in 0 in52.1 MPH82 MPH

280 (W)

03/17/192 F-6 F 0.07 in .5 in61.5 MPH110 MPH

270 (W)

03/16/1925 F2 F 0.24 in 2.3 in67.5 MPH97 MPH

280 (W)

03/15/1941 F25 F 0.04 inTrace 54 MPH105 MPH

250 (WSW)

Please Remember:

Safe travel in avalanche terrain requires training and experience. This forecast is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.

Avalanche danger may change when actual weather differs from the higher summits forecast.

For more information contact the US Forest Service Snow Rangers, AMC visitor services staff at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or seasonally at the Harvard Cabin (generally December 1 through March 31). The Mount Washington Ski Patrol is also available on spring weekends.

Posted 02/09/2019 at 7:08 AM.

Ryan Matz, Snow Ranger
USDA Forest Service
White Mountain National Forest