7:47 a.m., Wednesday, November 6, 2002 ***** WINTER STORM THROUGH THIS EVENING--BE PREPARED FOR AN INTERESTING DAY PLEASE READ THE DISCUSSION BELOW**** Winter sure seems to be establishing itself in the mountains! SNOW, SNOW, SNOW!!(Perhaps a bit of Rain?) Be prepared and well practiced in snow stability assessment, travel in avalanche terrain, and avalanche rescue. This is an early season GENERAL ADVISORY. Use of the 5 scale avalanche rating system will begin when conditions warrant. Until then new advisories will be issued as needed. We are getting very close to using the U.S. 5 scale danger rating, but realize avalanches are occuring even though we are still issuing 'General Advisories'. It is important to remember that until we have more widespread snowfields, and therefore avalanche danger, we will continue to issue General Avalanche Advisories due to the isolated hazard. Check csac.org frequently as we move through November and certainly check the latest avalanche advisory before heading into avalanche terrain. Snow began last night on the summit of Mount Washington around 10:00 pm with SE and S winds. Precipitation has slowly intensified through the evening hours and the NWS is predicting near 5 inches for the mountains before the change over to rain this afternoon. As this occurs expect the winds to shift from the S-SE to the NE. At 4 am the summit temperature was 15 F and currently stands at 19 F. High summit temperatures are anticipated to reach 25 F as warm air moves into the region later today. It appears the higher summits may be spared the rain the rest of us will receive. As this system moves out to sea colder air will come in changing rain back to snow for an additional inch or two this evening. It is difficult to say whether avalanche start zones from 5000ft down will receive liquid precipitation or stay frozen, in the form of snow, all the way through the storm cycle. If in the mountains today expect snow, rain, light winds and then high winds. Some of the snow that lingered into yesterday morning generated some natural avalanche activity in a few isolated pockets, namely Left gully, the Chute, and Central gully in Huntington. As mentioned in advisories over the past week these snowfields have been growing and yesterdays avalanche activity significantly increased the size of what will be the next cycles 'base'. 5 inches are expected through the morning hours, but will come in from the SE and S which will limit the amount of loading in the ravines. However some loading will occur and as the day progresses snow will become heavier creating a possible unstable, 'inverted' snowpack. As temperatures increase heavier snow will deposit over the lighter snow which fell during the past several hours. As temperatures rise instability should increase and if we do get rain in 'the current' avalanche terrain instability should increase rapidly. This triggers the old saying "if it rains in avalanche terrain go home". Although snowfields with southerly aspects are quite small a sun crust from yesterdays radiation may create some small unique instability problems. Expect some crossloading in the Ravines and loading of northern aspects with these S-SE winds, but they shouldn't load the snowfields of most concern as a W or NW wind would. Again, 'some' of these snowfields are Left Gully, the Chute, isolated areas growing beween rocks on the Headwall of Tuckerman, and the E and NE side of the summit cone. In Huntington Ravine, Central, the top of O'Dells, and the upper sections of Yale gully should generate the most concern. These snowfields, as well as, exposed ice are the most likely areas for possible avalanche activity during the next series of weather makers. Ice develops rapidly each fall in both Ravines and often act as an excellent sliding layer for avalanches to occur. Be aware that a small slab or sluff can be very dangerous. This is particularly true in the steep gullies and slopes of Tuckerman and Huntington Ravines for early season ice climbers. As a climber picks their way through a route they will usually cross small pockets of snow. Often this snow has deposited over blue ice, making for a poor bond at the interface. Consider this ahead of time and place protection before crossing suspect slopes. It doesn't take much snow to knock you off your feet and depending how high you are this could be a considerable problem. Remember if the snowfield is large enough to ski or recreate on it's large enough to avalanche. Approach early season snowfields with skepticism and be conservative while on them, near them, or in their runout zones. As always, this bulletin is one more tool to help you make your own decisions in avalanche terrain. It should be used along with your own snow stability assessments, knowledge of safe travel techniques, and skill in reading mountain weather's effect on the snowpack. Pull out your beacon and practice, ONLY YOU CAN SAVE YOUR PARTNER!! Review your safe travel rules, techniques for assessing snow stability, and sign up for an avalanche course. We will have all the avalanche courses offered in the valley this winter on our website, csac.org very soon. PLEASE REMEMBER: o Any new precipitation may increase the avalanche danger, this includes wind transported snow. o Obtain latest weather forecast before starting out. o For more information, contact the U.S. Forest Service Snow Rangers: AMC at Pinkham Notch Visitor Center or Hermit Lake Shelters. o This General Avalanche Bulletin will be updated as needed. Christopher Joosen, Snow Ranger USDA Forest Service White Mountain National Forest