Avalanche Forecast for Tuesday, April 7, 2020

This information was published 04/07/2020 at 8:46 AM.
A new forecast will be issued tomorrow.

NOT THE CURRENT FORECAST

This is an archived avalanche forecast and expired on 04/07/2020 at midnight.


The Bottom Line

Surface snow stability at mid elevations will decrease today as temperatures rise above freezing leading to the chance for sluff (wet-loose) avalanches on steep slopes. Watch for wet snow at the snow surface as an indicator that this hazard is increasing.  Clouds may limit snow surface warming, while direct sun will exacerbate this hazard on south aspects. Avalanche danger today is LOW.


Mountain Weather

Yesterday the summit reached a high of 23F under sunny skies and a west wind. Flurries very early in the day brought .3” of snow on the summit while Harvard Cabin received no measurable precipitation. High temperature at Harvard Cabin was 44F.

Today, temperatures will again reach the lower 20s F, with NW wind 25-40 mph. Partly sunny/clouds may limit the effects of solar radiation, and a chance for snow flurries are expected to result in no accumulation.

Tomorrow
, high cloud cover with temperatures rising to the upper 20sF. NW wind at 15-30mph. Clouds increase tomorrow (Wednesday) night with up to 1” snow possible. Looking further, up to 12” of snow possible late Thursday into Friday.

Primary Avalanche Problem – Wet Loose

Wet Loose

Aspect/Elevation

Likelihood

Size

Wet Loose avalanches will be possible as the snow surface warms above freezing. Snow surface warming may happen at all aspects as the temperatures rise, though direct sun on the snow surface will increase the likelihood and size at those locations. These “sluff” avalanches should be small, and found mostly on the steepest terrain. Watch for pinwheels and rollerballs as signs of increasing likelihood. Cloud cover today will be the largest determining factor contributing to this avalanche problem today. 

  Wet Loose avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.

Forecast Discussion

Snowpack changes look to be subtle for the next two days. Significant storm Thursday into Friday brings increasing avalanche danger to be aware of. As of today, NWS is calling for all/mostly snow.

Snow Plot Information

DateHN24HN24W
(SWE)
Density (%)HSTTotalAir TT MaxT MinSkyPrecipComments
04/13/20
06:15
0 CM 0.1 MM0CM206 CM-3.5 C7.5 C-7.0 COvercastRain
04/12/20
06:20
Trace 1.8 MMTrace216 CM-7.0 C-4.0 C-7.0 CFewNo precipitation
04/11/20
06:20
14 CM 23.1 MM 14%62CM222 CM-8.0 C-6.0 C-8.0 COvercastNo precipitation
04/10/20
06:30
53 CM 49.5 MM 12%NC200 CM-6.0 C-2.0 C-6.5 COvercastSnowView
04/09/20
06:25
0 CM 0.0 MM0CM158 CM-1.0 C8.0 C-4.5 CClearNo precipitation

Avalanche Log and Summit Weather

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
05/25/2054 F46 F 0.0 in 0.0 in18.7 MPH44 MPH

260 (W)

05/24/2054 F40 F 8.3 in 21 in8.3 MPH21 MPH

280 (W)

05/23/2055 F43 F 0.0 in 0.0 in15 MPH45 MPH

300 (WNW)

05/22/2055 F40 F 0.0 in 0.0 in37.4 MPH67 MPH

290 (WNW)

05/21/2053 F38 F 0.0 in 0.0 in29.4 MPH59 MPH

280 (W)

05/20/2050 F34 F 0.0 in 0.0 in29.4 MPH59 MPH

280 (W)

05/19/2041 F27 F 0.0 in 0.0 in15.3 MPH36 MPH

100 (E)

05/19/2050 F34 F 0.0 in 0.0 in11.4 MPH25 MPH

30 (NNE)

05/18/2045 F30 F 0.0 in 0.0 in14.7 MPH36 MPH

70 (ENE)

05/17/2040 F30 F 0.0 in 0.0 in17 MPH35 MPH

270 (W)

05/16/2037 F28 F .16 in 0.0 in38.8 MPH101 MPH

310 (NW)

05/15/2042 F32 F .95 inTrace 31.5 MPH95 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 04/07/2020 at 8:46 AM.

Jeff Fongemie
USDA Forest Service
White Mountain National Forest