845 AM PST THU MAR 06 2008 && ZONE AVALANCHE FORECASTS * OLYMPICS- Thursday: MODERATE avalanche danger below 7000 feet early Thursday increasing later Thursday morning and afternoon and becoming locally CONSIDERABLE on steeper sun exposed terrain Thursday night: MODERATE avalanche danger above 5 to 6000 feet and LOW below Friday morning: gradually increasing danger later Friday morning and becoming MODERATE below 7000 feet Friday afternoon and night: increasing avalanche danger Friday afternoon becoming CONSIDERABLE above 4 to 5000 feet and MODERATE below Friday night, with greatest danger developing on north, northeast and east exposures * WASHINGTON CASCADES NEAR AND WEST OF THE CREST, MT HOOD AREA- Thursday: MODERATE avalanche danger below 7000 feet early Thursday increasing later Thursday morning and afternoon and becoming locally CONSIDERABLE on steeper sun exposed terrain Thursday night: MODERATE avalanche danger above 5000 feet and LOW below Friday: gradually increasing danger later Friday morning and becoming MODERATE below 7000 feet through Friday afternoon, with greatest danger on sun exposed terrain Friday night: increasing avalanche danger becoming CONSIDERABLE above 4 to 5000 feet and MODERATE below, with greatest danger developing on north, northeast and east exposures * EAST SLOPES WASHINGTON CASCADES- Thursday: MODERATE avalanche danger above 4 to 5000 feet early Thursday increasing later Thursday morning and afternoon and becoming MODERATE below 7000 feet except locally CONSIDERABLE on steeper sun exposed terrain Thursday night: MODERATE avalanche danger above 6000 feet and LOW below Friday: gradually increasing danger later Friday morning and becoming MODERATE below 7000 feet through Friday afternoon, with greatest danger on sun exposed terrain Friday night: increasing avalanche danger becoming CONSIDERABLE above 5 to 6000 feet and MODERATE below, with greatest danger developing on north, northeast and east exposures SNOWPACK ANALYSIS After sun and warming related surface melt in many areas on Wednesday, clear skies overnight produced weak surface crust formation on most previously sun exposed terrain. Combined with continued snowpack settlement and some natural loose and isolated slab avalanche activity on Wednesday, these weather and avalanche factors produced a decreased avalanche danger in most areas overnight and early Thursday. However, a moderate avalanche danger remains, especially on steeper northeast through southeast exposures not receiving sunshine on Wednesday where some 8-16 inch soft slabs continue over an old crust formed mid-late last week. Field reports indicate that the bond of recent snows...both from the last Friday-Saturday storm and Mondays storm...is not particularly good either to each other or the crust formed mid-late last week, especially on northwest through northeast exposures above 4 to 5000 feet where some faceting may have developed near the recent crust. While better bonding both within the recent snow and to the old crust exists at lower elevations, this recent snow remains susceptible to the destabilizing effects of warming and melt associated with the high freezing levels and increasingly intense late winter sunshine. During the past few days, significant human triggered and natural slide activity confirms the considerable avalanche danger that developed as a result of the recent storm activity. While much of the recent slide activity has been of the loose variety, such loose or wet loose slides entrained much of the recent snow down to last weeks crust, with relatively impressive debris deposited in the path runouts. And as reported on yesterdays forecast, some 1- 2 ft human triggered slabs have occurred with some fortunate outcomes. DETAILED FORECASTS THURSDAY Variable mid and high clouds are likely on Thursday as a weak frontal system moves mostly north of the region and dissipates. Along with relatively light winds, considerable sunshine or filtered sunshine, and relatively high freezing levels, this weather should produce significant warming and melt of near surface snow. As a result, an increasing avalanche danger is expected later Thursday morning and afternoon, especially on sun exposed terrain where natural avalanches should become possible and human triggered avalanches probable. Such danger should be greatest on steeper terrain below trees, rocks, cliffs or overhanging cornices, where cornice releases or snow melting and releasing from tree boughs and warmed rock areas are most likely to trigger slides on the slopes below. The probability of such slides should be greatest on slopes showing no evidence of recent avalanche activity; and back country travelers are urged to use caution in route selection and perform stability tests prior to traversing or descending slopes of questionable stability. THURSDAY NIGHT, FRIDAY MORNNG Variable high clouds, light winds and slowly lowering freezing levels should allow for decreasing danger overnight as previously melting surface snow refreezes and creates a slowly expanding surface crust. However, some surface hoar formation should be closely monitored as increasing clouds and lowering freezing levels on Friday may allow it to persist long enough to be buried by new snow late Friday. Increasing sunshine or filtered sunshine in most areas Friday morning should result in a gradual increase in the danger, mainly on sun exposed terrain, where further loose or isolated slab slides are possible. FRIDAY AFTERNOON AND NIGHT Increasing clouds and increasing light rain or snow should spread into the Olympics during the afternoon, and the Cascades and Mt Hood area mid-late Friday afternoon and evening, becoming moderate Friday night. Along with increasing winds and substantially lowering freezing levels, this weather should produce generally increasing avalanche danger mid-late Friday, especially on wind loaded north, northeast and east facing terrain above about 5000 feet where a weaker bond of new snow to an old crusted or refrozen snow surface is expected. At lower elevations rain changing to snow late Friday should allow for a better bond of new snow to the old refreezing snow surface; however variations in wind speed and snowfall rates Friday night and early Saturday should allow for some weak layers to form within the new snow, especially on more heavily wind loaded terrain. &&