The National Weather Service Forecasts-

TODAY...RAIN. HIGHS AROUND 47. SOUTHEAST WIND 10 MPH SHIFTING TO THE NORTHEAST IN THE AFTERNOON.

TONIGHT...RAIN. LOWS AROUND 37. NORTHEAST WIND 10 MPH.

FRIDAY...RAIN...HEAVY AT TIMES. SNOW LEVEL 600 FEET INCREASING TO 1300 FEET IN THE AFTERNOON. HIGHS 39 TO 45. NORTHEAST WIND 5 TO 15 MPH BECOMING SOUTHEAST 10 TO 20 MPH IN THE AFTERNOON.

Tram summit temperatures have remained well above freezing for the last several days.

We have seen 1.2\" of precip in the last 36 hours at Tram summit elevations with no significant snow at that elevation.

We may have a little new snow at upper elevations. Below the snow line this rain is eroding the bonds in the snow. Above the snow line this new snow is probably not bonding well to the old icy snow surface.

The forecast calls for over 1.3\" of rain in the next 24 hours and over 2\" of rain in the next 48 hours. This should continue to add stress to the snowpack.

Temperatures are forecast to fall over the next 24 hours then to rise again tomorrow afternoon. Look to see a continuing to weaken snowpack at lower elevations. At snow level and above this is a critical loading rate and may be enough to start natural avalanches. Be especially cautious in windloaded areas if you venture into snow level elevations and above.

As tomorrows warming occurs this will be the critical point for this storm. With snow first being deposited on a poor bed surface and then adding up rapidly... before becoming upside down and finishing off with a warming trend and significant precip.

Avalanche danger is Moderate today and on the rise.

Expect to see small wet avalanches early on in the event. Expect the possibility of avalanches sizes to grow throughout the event. Expect to see considerable avalanche danger tomorrow depending on how much new snow we get and what the freezing levels do.

Use caution over the next two+ days folks.

Upside-Down Storm:

Lucky for us, most storms deposit new snow with denser snow on the bottom and lighter snow on top?just the way we like it. This is because most snow comes from cold fonts, which usually start out warm and windy but end up cold and calm. But sometimes snowstorms deposit denser, stiffer snow on top of softer, fluffier snow. We call this ?upside down? snow. We often call it ?slabby? or ?punchy? meaning that you punch through the surface slab into the softer snow below, making for difficult riding and trail breaking conditions. It also means that we need to carefully monitor avalanche conditions within the new snow because?by definition?a denser slab has been recently deposited on top of a weaker layer, which should make anyone?s avalanche antennae stand at attention. Most instabilities within upside-down snow stabilize within a day or two.

The kind of weather conditions that often produce upside-down snow include warm fronts, storms in which the wind blows harder at the end of the storm than the beginning, or storms that end with an unstable airmass, which can precipitate a lot of graupel within instability showers.

Tomorrow the upside down event will begin with diurnal warming throughout the day.