Good Thanksgiving morning backcountry travelers this is Carl Skustad with the Chugach National Forest Avalanche Information Center on Thursday, November 26 at 7 am. This will serve as a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (advisory does not apply to highways, railroads, or operating ski areas).
The Chugach National Forest Glacier Ranger District opened Turnagain Pass to snowmachines yesterday. All CNFAIC Staff areas including Johnson Pass, Placer, Twenty-Mile, and all areas on the Seward Ranger District will remain closed until there is more snow. The Turnagain Pass open riding area is on the west side of the highway from Bertha Creek Campground north to the Forest boundary near the Turnagain Arm.
Avalanche danger may exist at any time in backcountry areas like Turnagain Pass on the Chugach National Forest, whether these areas are open or closed. The US Forest Service does not close areas due to avalanche danger. When areas designated for use by snowmachines on the Chugach National Forest are closed, a primary reason is for the protection of natural resources in accordance with the current Forest Plan. Similarly, on open sign does not mean that it is safe. There are many inherent dangers associated with traveling in the backcountry including avalanches. Safe backcountry travel requires training and experience. You Control Your Own Risk by choosing where, when and how to travel. The Chugach National Forest Avalanche Information Center provides pertinent information to assist you in making your own decisions for traveling in these backcountry areas.
Opening of these motorized areas in the early season can be subject to immediate closure based on sufficient snow to prevent the tracks of a snowmachine from tearing up vegetation. If the weather changes and the snowpack gets too thin to prevent resource damage, then areas may be closed again. It is your responsibility to check the official open/closed status of these areas with the Chugach National Forest. CNFAIC Staff resources for information regarding these motorized areas can be found through the Glacier Ranger District, and/or the Chugach National Forest Avalanche Information Center.
AnCNFAIC Staff band of precipitation came through the area last night and produced a nice 3-6 inch blanket of snow for our Thanksgiving.
We received 5 inches of snow in the Girdwood Valley with 6-8 higher on Alyeska. Current temperatures range from 20-27 deg F. Summit Lake is a little cooler at 16 deg F. Winds are light out of the east, southeast, and southwest.
The Center Ridge weather station in Turnagain Pass (1800 ft) is reporting 23 deg F, .3 inches of water equivalent and 2-3 inches of snow.
The Sunburst weather station in Turnagain Pass (3800 ft) is reporting 20 deg F, and wind 7- 11 mph out of the SW.
The NWS forecasts the next precipitation to work it’s way into the area this afternoon with rain and snow mixed at lower elevations and snow above the freeze line. I expect the freeze line to be 500 to 800 ft. The models have not been in agreement for the folks at the NWS so the amount of snowfall ranges from 0 to 12 inches. Stronger winds are also forecasted.
If you haven’t been in tune with the weather this week, the last significant event occurred on Monday the 23 when we received 2-3 feet of new snow above 800 ft and easterly winds up to 60+ mph.
WESTERN PRINCE WILLIAM SOUND-
500 AM AKST THU NOV 26 2009
…STRONG WIND THURSDAY EVENING THROUGH LATE THURSDAY NIGHT THROUGH
PORTAGE VALLEY AND TURNAGAIN ARM…
.TODAY…SCATTERED SNOW THIS MORNING. RAIN AND SNOW THIS AFTERNOON.
AREAS OF BLOWING SNOW NEAR WHITTIER THIS MORNING THEN THROUGH PORTAGE
VALLEY AND ALONG TURNAGAIN ARM BRIEFLY THIS AFTERNOON. SNOW
ACCUMULATION UP TO 1 TO 4 INCHES POSSIBLE. HIGHS IN THE 30S. LIGHT
WINDS BECOMING EAST 15 TO 20 MPH IN THE AFTERNOON. THROUGH PORTAGE
VALLEY AND TURNAGAIN ARM…EAST WIND INCREASING TO 25 TO 50 MPH
IN THE AFTERNOON.
.TONIGHT…SNOW AND RAIN. SNOW ACCUMULATION 2 TO 5 INCHES…EXCEPT UP
TO 8 INCHES AT HIGHER ELEVATIONS. LOWS IN THE MID 20S TO MID 30S.
SOUTHEAST WIND 15 TO 30 MPH. THROUGH PORTAGE VALLEY AND TURNAGAIN
ARM…EAST WIND 30 TO 50 MPH.
.FRIDAY…SCATTERED SNOW SHOWERS. HIGHS IN THE 30S. SOUTHEAST WIND 10
TO 15 MPH. THROUGH PORTAGE VALLEY AND TURNAGAIN ARM…EAST WIND 25 TO
35 MPH BECOMING VARIABLE 10 MPH IN THE AFTERNOON.
.FRIDAY NIGHT…MOSTLY CLOUDY WITH SCATTERED SNOW SHOWERS. LOWS
IN THE LOWER 20S TO MID 30S. VARIABLE WIND 10 MPH. NEAR SEWARD…
LIGHT WINDS BECOMING NORTH 15 MPH AFTER MIDNIGHT.
.SATURDAY…CLOUDY WITH A CHANCE OF SNOW. HIGHS IN THE UPPER 20S
TO MID 30S. NORTHEAST WIND 10 TO 15 MPH. NEAR SEWARD…SOUTH WIND
10 TO 20 MPH SHIFTING TO THE NORTH IN THE AFTERNOON.
TEMPERATURE / PRECIPITATION
SEWARD 37 34 39 / 100 100 80
GIRDWOOD 34 27 34 / 70 80 80
An educational opportunity is coming up to learn more about mountain weather, Dec 5th. Weather for the Backcountry Traveler Lecture Series. Given by AK Avalanche School and the NWS 9am-5pm visit www.alaskaavalanche.com for more info.
Heightened avalanche conditions on specific terrain features today. Evaluate snow and terrain carefully. Natural avalanches unlikely, human triggered avalanche possible. This MODERATE avalanche rating will increase to CONSIDERABLE this afternoon if the area you are traveling in receives rain or significant new snow or wind. If the rain line goes higher than 800 feet we will see natural avalanche activity at those elevations. CNFAIC Staff areas of concern include steep rollovers around tree line. This is where Matt and I found the largest facets (weak sugary grained snow) and associated crust three feet deep. We observed multiple collapses of the snowpack at this mid elevational band. Moderate test results were recorded on this layer. Tests at higher elevations (3000 ft) also had moderate results (SCT 19 Q2). The last and most significant area of avalanche concern today has to include the high alpine. The wind blown snow above 3000 ft smells of a rat. Hanging snowfields look tempting, but reek of early season injury. A mistake in this arena could have significant consequences.
The early season snow pack in South Central Alaska is always full of surprises because it needs time to adjust. Every year, people get caught off guard in November and December because they are trying to use Turn again Pass like they do in the middle of winter. The facts are that the snowpack is not ready for aggressive skiing, snowboarding, or snowmachining yet. The snowpack is still young, give it some time to adjust over the next couple weeks and next couple of storms. Moderate terrain for a moderate snowpack.