Avalanche Advisory for Sunday, January 7, 2018

Huntington Ravine has MODERATE and LOW avalanche danger. Central Gully has Moderate avalanche danger. Evaluate snow and terrain carefully. All other forecast areas have Low avalanche danger. Watch for unstable snow on isolated terrain features.

Tuckerman Ravine has MODERATE and LOW avalanche danger. Sluice, Lip, Center Bowl, and Chute have Moderate avalanche danger. Evaluate snow and terrain carefully. All other forecast areas have Low avalanche danger. Watch for unstable snow on isolated terrain features. The Little Headwall may still have open water.


AVALANCHE PROBLEM: Moderate rated slopes contain firm wind slabs. These slabs are mostly firm (1F-P) and probably stubborn but, as always, careful evaluation before committing to a slope would be good practice today. Lots of visual cues exist to indicate slopes are wind hammered due to the continuous wind transport of snow grains on the ground. Low rated areas are more eroded down to older hard slabs due to the scouring action of avalanches followed by strong winds. The same smooth slabs are also present in Low rated areas but are smaller and present more opportunities to get around them. Natural avalanche activity in unlikely in all areas today but evaluate snow and travel carefully, even in areas with a Low danger rating.


WEATHER: The temperature is currently -17F on the summit with northwest winds at 80 mph range. Winds have blown steadily from the west-northwest and northwest in the 80-100 mph range over the past 24 hours with even higher gusts. No new snow was recorded in the past 24 hours on the summit. Skies are currently clear with some thin summit fog and wind transported snow at the ridgetops. Winds will diminish further to the 50-70 mph range today and shift to the west. The temperature at the summit will climb to near 0F through the day under sunny skies.


SNOWPACK: So far, early morning light has revealed possible signs of avalanche activity in Chute and Left Gully in Tucks and Central Gully in Huntington. Debris isn’t obvious though due to the continuous wind hammering that our terrain has received in the past 24 hours. The Lip has a distinct crown line but has reloaded quite a bit. Our low rating comes today with a reminder that low avalanche danger doesn’t mean no avalanche danger. We are still dealing with a midwinter snowpack with lots of variability across slopes and elevations. Use safe travel practices and only expose one person at a time and carry your avalanche rescue equipment just in case. A crown line in one of the gullies (Main?) in Gulf of Slides just above the mid slope choke point was also observed this morning.


You will see changes to the advisory in the coming weeks and months as we try to find more effective ways to present the avalanche and mountain safety message in an efficient and helpful way. Today’s danger rating section purposely lacks likelihood of avalanche information which you will find in the problem section or in the North American Pubic Avalanche danger scale posted on kiosks or at the link on this page below the map.

Please Remember:
• Safe travel in avalanche terrain requires training and experience. This bulletin 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 Harvard Cabin.
• Posted 8:00 a.m., Sunday, January 7, 2018. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856