February 16, 2002

Good morning, this is Ron Johnson with your Gallatin National Forest
Avalanche Advisory issued on Saturday, February 16th, at 7:30 am.  A
Recreation Trails Grant administered by the Montana Department of Fish,
Wildlife and Parks is the sponsor of today's advisory.  Though we work
closely with the local ski areas, these advisories do not apply to them.

                CURRENT CONDITIONS AND WEATHER DISCUSSION:

The ridge of high pressure that was responsible for yesterday's clear
skies, light winds and warm temperatures will influence today's weather.
There is some moisture ahead of a low pressure system that is currently off
of the coast of California.  This moisture will move into Southwest
Montana, which means that, later today, the sky will become partly cloudy.
No precipitation is expected during the next 24 hours.  The next chance for
snow looks to be Sunday night and Monday.   This morning there is a decent
temperature inversion with valley temperatures in the single digits and
mountain temperatures in the upper 20s to low 30s.  Today, mountain
temperatures will remain warm with readings in the 30s.  Ridgetop winds
will be from the southwest to northwest at 10 to 20 mph.

                    SNOWPACK AND AVALANCHE DISCUSSION:

The Bridger Range, northern Gallatin, and northern Madison Ranges:

The only avalanche activity, from this week, that I'm aware of, occurred
Thursday.  Wind blowing a few inches of new snow deposited wind slabs near
the ridgetops at higher elevations, especially in the mountains around 
Big Sky.  These wind slabs were isolated and were only active for a short
period of time.  Doug was in the northern Madison Range earlier this week,
and I was in the northern Bridger Range with Doug on Wednesday.  The
snowpack in these areas didn't have any stability problems that would be
affected by the current weather conditions.  So, for today, the avalanche
danger in the northern mountains is considered to be LOW.

The southern Gallatin, southern Madison and Washburn Ranges, the Lionhead
area, and the mountains around Cooke City:

Yesterday, my partner and I enjoyed a wonderful day checking the snowpack
conditions in the southern Madison Range, near Bacon Rind Creek.  We didn't
see any recent avalanches or experience any obvious signs of instability
such as collapsing or cracking of the snowpack.  Given the current weather
conditions, the snowpit we dug didn't reveal any weak layers that concerned
us.  While we found a stable snowpack, there are some slopes in the
southern mountains that have a buried layer of surface hoar or faceted 
snow on top of a buried ice crust.  These weak layers are getting stronger and
are not widespread, however their existence causes enough of a concern 
that a MODERATE avalanche danger exists on all slopes steeper than 35 degrees.
The avalanche danger on less steep slopes is LOW.

                                A REMINDER:

One way to deal with a moderate avalanche danger or even a low avalanche
danger is to assume every steep slope could avalanche.  If you make this
assumption, then you should only expose one person at a time on any
avalanche terrain.  You should also travel with a properly equipped and
trained partner who will watch your every move, like a hawk.

Scott will issue the next advisory tomorrow morning at 7:30 am.  

END