745 AM PST SUN FEB 24 2008 && ZONE AVALANCHE FORECASTS * WASHINGTON CASCADES, OLYMPICS, MT HOOD AREA- LOW avalanche danger below 7000 feet slightly increasing Sunday morning through mid-day, mainly on north, northwest and west exposures above 4 to 5000 feet. Avalanche danger decreasing later Sunday afternoon and night and becoming generally LOW below 7000 feet. Slightly increasing avalanche danger later Monday morning and afternoon, mainly on sun exposed terrain. Decreasing danger Monday night. SNOWPACK ANALYSIS Continued snowpack settlement, increasing surface crust formation, relatively cool daytime temperatures, and only very light recent snowfall have all combined to produce a mostly stable snowpack and generally LOW avalanche danger early Sunday. Field reports indicate mostly trace amounts to an inch or so of new snow over an increasingly thick surface crust on most exposures, with the crust varying from semi-breakable to walkable to almost drivable in places. Several more buried crusts lie interspersed with multiple settling snow layers of 1-4f hardness within the upper 1 to 2 feet of the snowpack in most areas. While some minor faceting may be developing near these buried crusts, such slow and limited weakening is not expected to be a significant factor in future avalanching, at least not currently. Also, while some relatively soft recycled powder may still exist on some higher elevation north exposures, this softer near surface snow is also quite stable. Of more immediate concern is the firm near surface crust and the potential for uncontrolled sliding on this smooth hard surface after a fall. Travelers are encouraged to use caution traversing steeper terrain with such a crust, especially on slopes above terrain traps such as cliffs, rocks or trees which would result in an unpleasant outcome after a long slide on this icy surface. While neither the crust nor small amounts of new snow pose a significant avalanche problem at the present time, the combination of such layering will become much more of a concern whenever future heavier snow loading returns to the Northwest. Although a weak disturbance should move over the area later Tuesday into Wednesday morning, longer range forecast models indicate that briefly stronger westerly flow and associated heavier snowfall should return to most Northwest mountain locations late this week. DETAILED FORECASTS SUNDAY, SUNDAY NIGHT Mostly cloudy skies and some light rain or snow that spread northward overnight should continue Sunday morning, along with slightly increased ridgetop and pass winds. While any snowfall should be very light and accumulations minor, a slight increase in the danger is possible on north, northwest and west exposures where some very shallow wind slabs may develop above about 4 to 5000 feet, mainly in the southern and central Washington Cascades and Mt Hood area. While the avalanche danger from new snowfall should remain relatively low, back country travelers should exercise caution due to the strong icy crust that should continue beneath small amounts of new snow in many areas, as serious injury can occur from falls on this surface into terrain traps like cliffs, rocks or trees. The highly variable snow surface combined with frozen debris from previous avalanching may pose additional challenges in many steeper slope run outs. Also some large cornices which developed during stormy weather in early-mid February and have not yet released should be avoided, as they can still collapse during daytime warming. With gradually decreasing clouds, showers and winds expected Sunday afternoon and night, any shallow slabs that have developed earlier Sunday should quickly settle with a return to generally LOW danger below 7000 feet by early Monday. MONDAY, MONDAY NIGHT While generally decreased clouds are expected Monday, some weak shower bands are still possible as a weak disturbance moves over the top of building ridging offshore. However, any snowfall amounts should be minimal with little more than trace accumulations expected in most areas. This weather should result in a slightly increasing danger during the later morning and afternoon hours, mainly on steeper, south facing slopes receiving sun breaks between showers. On such slopes, some small sluffs or small loose slides are possible, mostly running on the recently developing crust. Decreasing clouds and slow clearing should spread northward mid-late Monday afternoon and evening, with mostly fair skies, light winds and only a slight rise in freezing levels in most areas expected Monday night. This weather should allow a return to generally low danger as previously wet surface snow refreezes and strengthens. &&