Presidential Range

You are unlikely to trigger an avalanche today. Warm temperatures and strong sunlight will continue to melt and settle the snowpack. Use normal cautions when traveling in avalanche terrain and carefully assess for springtime mountain hazards to help reduce your exposure.

This week has seen a significant transformation of the snowpack at all elevations, attributed to a continued trend of warm temperatures above freezing for the fifth consecutive day across all elevations. The summit of Mt. Washington has seen a 12-inch reduction in snowpack depth due to melting and settlement, compounded by almost 2 inches of rain in the last five days, which has accelerated the snowpack's settlement. The snowpack at Hermit Lake lost almost 7 inches of height during the same time period. 

At lower elevations, the warm temperatures have largely eradicated the snowpack, shifting our focus to the middle and upper elevations where avalanche concerns remain. Although lower elevations are currently not a primary concern, we will keep monitoring these areas and reintegrate them into our avalanche forecast as necessary, based on evolving conditions.

Recent Weather:

The latest weather event yesterday deposited up to 5.9 inches of heavy, wet snow at elevations above 4500 feet, adding a moist layer on top of an already saturated snowpack. Despite strong northerly winds, the wet nature of the snow has prevented significant wind slab formation, allowing this new layer to settle into and adhere to the existing snowpack. For the first time in several days, temperatures dropped below freezing last night at elevations above around 1600 feet. 

Current Snowpack Conditions:

The sustained warmth, despite initially increasing instability due to water permeation over the last several days, has ultimately enhanced the snowpack's stability. This stabilization occurred through destratification, which involved the breakdown of ice layers and the unification of the snowpack's structure. Consequently, the snow has become more uniform, significantly reducing the potential for slab avalanches.  

Considerations for Today: 

Recent instability was driven by significant meltwater and rain permeating the snowpack. With precipitation over and below freezing temperatures last night, much of this water has drained or refrozen, reducing the chances for a wet snow avalanche at least for the morning hours.

• Small Wind Slabs? The Mount Washington Observatory recorded 5.7 inches of new snow yesterday morning. Field observations from yesterday found a consistent layer of wet new snow at middle elevations, without any evidence of snow drifting. However, the cooler conditions at higher elevations leave room for the potential formation of a few small wind slabs, especially on southern aspects. If present, these wind slabs are expected to be well adhered to the underlying snowpack, making them difficult to trigger. Should you find an area of recent snow that's drifted deeper than the top of your boots, assess the stability of this layer and consider the potential risks before proceeding.
• Wet Avalanches and a Soggy Rotten Snowpack: Despite a cold night that brought temperatures below freezing at middle and upper elevations, today's clear skies and rising temperatures are expected to heat the snow surface again, particularly on south-facing slopes. While the likelihood of encountering wet snow avalanches has decreased compared to previous days, it is not eliminated. Key indicators include finding a soggy snowpack, where frozen surface snow melts under the afternoon's warm temperatures and strong sunlight. This effect is particularly pronounced at middle elevations, where warmer temperatures are expected. Also keep in mind the recent warm spell has infused the snowpack with substantial meltwater. Although the rate of meltwater production has decreased, allowing some of the soggy snow to drain, the transition to a firmer snowpack is gradual and ongoing.

• Springtime Mountain Hazards: It’s worth paying attention to common springtime mountain hazards when traveling in steep avalanche terrain. These include but are not limited to falling rock and ice, undermined snow, and loose-wet avalanches. Some of these hazards are predictable and some are not. Plan accordingly to mitigate the risk and reduce your exposure. 

Refresh your knowledge about springtime mountain hazards here.

OBSERVATIONS: Please consider submitting an observation of what you are seeing in your travels. Submitting an observation hones your skills, informs other users, and improves our forecasts.