This advisory expires at midnight
Tuckerman Ravine has MODERATE and LOW avalanche danger. The Sluice, Lip, Center Bowl, the Chute, Left Gully and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Lobster Claw, Right Gully, Lower Snowfields, and Little Headwall have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow in isolated terrain features within these locations.
Huntington Ravine has MODERATE and LOW avalanche danger. Central, Pinnacle, Odell, and South Gully have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow in isolated terrain features within these locations.
AVALANCHE PROBLEM: Wind Slabs leftover from Monday’s howling winds are still a problem due to very slow consolidation with the cold temperatures engulfing the mountain. In addition, new Wind Slab today will develop with snow showers and a building W wind. Although precipitation is forecasted to remain light the W wind, currently at 55mph (88kph), should increase to 80+ (128+kph) this afternoon. Expect areas facing E, that are in the most protected lee of terrain features, to hold the main avalanche problem today. These locations are also the locales that reloaded the most after Monday’s avalanche cycle. The areas rated at Moderate are the most protected against strong W winds and have greater potential for someone to trigger an avalanche. Expect the steepest and most sheltered of these locations such as the Lip and Center Bowl to be at the top of the Moderate rating ready to jump the fence to Considerable. This is most likely in the afternoon if snow showers continue through the morning giving us measurable accumulations. Therefore, expect the natural avalanche potential to be increasing due to new Wind Slab. Because of this anticipate the likelihood of natural avalanches to be transitioning from unlikely towards possible if we receive 2+” (5+cm) in these aforementioned places.
WEATHER: The Mountain is being coy today, veiled in clouds, fog, snow showers, and blowing snow. Snow showers began last night at about 7pm. This is expected to continue today with winds from the W at 50mph (80kph), increasing to 80 (128kph) with higher gusts late. Temperatures will remain very cold, hovering in the negative teens F, on the summit producing harsh wind chills. Tonight and tomorrow another system will be moving through the mountains bringing snow to our region. Being on the northern fringe of the main precipitation shield, we should only pick up around 3-4″ (7.5-10cm) out of it.
SNOWPACK: As Jeff mentioned yesterday, despite several good storms and over 5 1/2 feet for the month at the Summit, overall snow coverage in both ravines is still pretty thin. This is due in large part to a lack of early season snow, and also to the thaw from about a week ago. Saying all this we are in the gaining mode once again. If you look closely at our pictures you will see most areas are continuing to grow. This is true even though avalanche activity is shedding snow from slopes and bringing it down to deposition zones in the run outs. As bed surfaces grown in the start zones, as well as the smoothing of terrain in the paths below, you will likely see more avalanche activity and snow traveling further in their paths. Currently, some new wind slabs will grow on both some of the old icy surfaces and on the newly formed slabs that resulted from our recent storm. Generally, two main wind slab issues exist to recall and remember when traveling in avalanche terrain today. First is the cold new snow that could fail on the icy crusts from the rain event mid-December that is still peppered about. And second, new snow loading on the leftover slabs from Monday’s big wind. It is quite plausible these new slabs, forming on the slabs from 48 hours ago, could fail at this interface and then step down to the icy crust depending on its depth. The variability is once again intense, so be sure to constantly evaluate and anticipate changes as you move. You will certainly find slabs between strong and weak within a small area.
- Safe travel in avalanche terrain requires training and experience. This advisory 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.
- Anticipate a changing avalanche danger when actual weather differs from the higher summits forecast.
- For more information contact the Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin.
- Posted 7:50am Wednesday, January 1, 2014. A new advisory will be issued tomorrow.
Christopher Joosen, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856