The National Weather Service Forecasts-

TONIGHT...RAIN. LOWS AROUND 36. SOUTHEAST WIND TO 15 MPH.

THURSDAY...RAIN. HIGHS AROUND 40. SOUTHEAST WIND 10 MPH.

THURSDAY NIGHT...RAIN. LOWS AROUND 33. SOUTHEAST WIND 10 TO
15 MPH.

It was clear and cool late last week for several days. This comes following a week of rains to summit elevations.

The lower snowpack is quite solid in place.

Saturday we received almost 4\" of new snow at upper mountain elevations.

Monday we were able to see that this 4\" had created slab formations in our urban starting zones. Some of these slabs failed naturally and several are still hanging.

As we went through last night and into today the avalanche danger rose as we started to place this cold new snow on the few weak shallow slabs that are in place.

Even without the presence of the slabs and weak layer, as this storm comes in accompanied by warming temps over the next few days danger levels are expected to rise.

Temperatures have warmed by 5 degrees in the last 23 hours.

During that time we have received 27mm of precipitation which in turn left about 28 cm of snow.(nearly a foot at tram summit)

Winds out of the south (165 degrees) have been cross loading our slopes with average speeds of about 15 knots.

Currently temps at tram summit level are -1.

We are expecting as much as another 5 degrees of warming in the next 24 hours during which time we are predicted to receive about ?? of precipitation.

If this stays as snow up high until tomorrow am that could be as much as another 6? of snow.

If it turns to rain sooner you will have less snow and higher possibility of slides.

Between now and tomorrow pm you should see some natural avalanche activity.

This upside down snowpack will want to releive itself off of trees, rocks, and steep open pitches. Cornices will be forming weak and dropping off during the warm loading trend.

Slide sizes are not expected to be huge yet we should start to see some activity as this system continues throughout today and into tomorrow.

Remember in the backcountry always bring your transceiver, probe, shovel and partner.

Limit exposure to avalanche paths in the community.

Avoid avalanche zones as much as possible during periods of HIGH and EXTREME danger

Be safe and enjoy the new snow today.

Temperature trend:

As temperatures increase, the snowpack undergoes settlement, deforming and becoming denser. Settlement on an incline results in creep, a slow downhill motion.

?If air temperatures increase rapidly (more than 15?F or 8?C) in less than 12 hours, the rate of creep increases, which can lead to avalanching. This is most critical when temperatures are near or above freezing because the rate of creep increases exponentially with rising temperature.

?If temperatures increase slowly over several days, settlement rates are slower. If air temperatures never rise above freezing for very long, the snowpack deforms slowly and creep rates are slower.

?As temperatures decrease, settlement and creep rates also decrease.

?Prolonged periods of cold temperatures promote the metamorphic processes that form weak layers.

?Warm days and cold nights strengthen the pack, especially overnight and during early morning hours.

?Several days of warmer temperatures followed by colder temperatures also strengthen the pack.

Key points:

?Rapid rises in temperature can destabilize a pack, while slow rises stabilize it (especially if a cooling trend follows)

?Long periods of cold temperatures build weaker snow, which isn?t a problem until the next significant snowfall