Avalanche Advisory for Tuckerman and Huntington Ravines
Posted: 8:34 a.m., Saturday, January 13, 2007

Tuckerman Ravine will have LOW avalanche danger today. Natural avalanches will be very unlikely and human triggered avalanches will be unlikely except in isolated pockets. Normal caution is advised. This Low danger forecast is developing currently so read on below. Hillman's Highway, the Lower Snowfields, the Little Headwall and Right Gully have little to no snow in them so the 5-Scale danger rating does not pertain to these areas. Forecasts for these locations will begin when needed.

Huntington Ravine is still under a General Avalanche Advisory. A General Advisory is issued when instabilities are isolated within the entire forecast area. However it's important to realize that avalanche activity may occur within these locations before the issuance of a 5-scale forecast. This is a critical fact to remember. Under a General Advisory you need to make your own avalanche stability assessments before venturing into any open slopes.

Warm temperatures overnight brought Hermit Lake to 39F (4C) with light rain and drizzle. As of 700 am we received .19"(.47cm) of rain but temperatures are beginning to plummet rather quickly as the summit as dropped from 28 to 23F (-2 to -5C) over the past hour. This trend is expected to continue making it into the single digits F by dark. Avalanche start zones have gone through some quick stabilization over the past 24 hours with temperatures above freezing and some light liquid precipitation. The dropping temperatures will continue this process by freezing free water in the snowpack locking round snow crystals together. This will likely create a breakable crust as opposed to a firm concrete lock up due to limited amounts of liquid water in the snowpack. Nonetheless the increase in tensile strength through this bridging process will improve stability in the start zones. Until this trend moves forward over the next few hours realize we are moving from Moderate to Low avalanche danger in all Tuckerman forecast areas early this morning. Freezing temperatures building a crust will confirm we have moved into the Low forecast.

We are expected to break out of the fog this afternoon and under go some partial clearing due to the cold front moving out this morning's moisture. As the front moves through we could see some snow showers with little accumulations, but it could slow crust development slightly by insulating the warmer snowpack below. The next snow event will enter the mountains Sunday afternoon and then another moisture band for all day Monday. Runs differ considerablely between the ETA and the GFS models with 10" (25cm) and 4"(10cm) respectively. Unfortunately the GFS has been more accurate as of late and is expected to be more in keeping with Monday's reality. So at this point I think we can bank 3-4" (7.5-10cm) and hope the track bumps north a bit boosting snow totals. Hope for the best.

Huntington continues to rebound from last week's devastating rain, but coverage is still scant. This still causes the "General Advisory" to be issued. The northern gullies have the thinnest lines compared to Central, Pinnacle, and over to O'Dells. Currently the first snowfields of concern will likely be at the bottom and middle of Central and the exit gullies of O'Dells. We mention them because they offer some of the largest bed surfaces in Huntington, but they are still isolated concerns within their entire forecast area. Remember climbs are thin in places and anticipate unusual conditions including thin ice over rock in the typically straightforward Central gully.

Please Remember:
•   It is impossible to accurately predict natural events, such as avalanches, in every instance. This Advisory is one tool to help you make your own decisions in avalanche terrain. It should be used along with safe travel techniques, snow stability assessments, an understanding of weather's effect on the snowpack, and proficiency in avalanche rescue.
 
•   You should obtain the latest weather forecast before heading into the mountains. Anticipate a changing avalanche danger when actual weather differs from the National Weather Service forecast.
 
•   For more information, contact the U.S. Forest Service Snow Rangers, the HMC Caretaker at the Harvard Cabin, and the AMC at Pinkham Notch Visitor Center or Hermit Lake Shelters. This advisory will expire at midnight.

Christopher Joosen, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856
 
This is the Official Tuckerman Ravine website.  Occasionally the remoteness of Tuckerman Ravine, weather, or communication problems prevent the website from being updated immediately.  Check the date, and if it is not the most recent, you can also call the National Forest Service's 24 hour avalanche hotline at (603) 466-2713 (ext. 4)

Avalanche Advisory Archives.

United States Avalanche Danger Descriptions.

Échelle Canadienne de risque d’avalanche.

Back to the Tuckerman Ravine Home Page

†.5>Av†/