Northwest Inland

Fair - Forecast snowfall amounts are uncertain on Thursday

Strong southwest winds are expected to swing more westerly by Thursday morning. Moderate precipitation should continue overnight Wednesday and during the day Thursday bringing another 10 cm to treeline elevations by Thursday morning. A further 10 cm of snow at treeline during the day on Thursday is forecast to be combined with very strong and gusty westerly winds. A weak ridge of high pressure should develop briefly on Friday. The wind should drop a bit, but still be about 40-60 km/hr from the west with flurries. The next Pacific system should move in from the coast overnight or early Saturday morning. This system is still a few days away, but is forecast to combine very strong southwest winds, heavy precipitation, and freezing levels rising to about 1000 metres. The west of the region may see higher snowfall amounts, and the East may see less.

No reports of avalanches from the region. I expect that there has been a natural cycle during the storm. We may not get many observations until the brief lull in the weather on Friday.

The storm brought another 20 cm overnight into Wednesday morning. Windslabs and storm slabs continue to develop. I have left in the snowpack information that we have gathered over the last few days, and updated the depths above the layers.I am going to call the facet layer that is buried about 50cm, the January 20th FC layer. This layer has only been buried a few days, but due to the very cold temperatures when it was buried and the continued cooler conditions during the recent storm, this layer may continue to be triggered by light loads. Tests on this layer in the Seaton Basin are producing moderate shears that are sudden planar in character. Shears that "pop" and slide off the block very easily can give us some clues about the ease of triggering and the extent of propagations. In the Howsons, this facet layered was buried with very little wind effect in the alpine, at the same time that the northeast outflow winds were howling in Terrace. The next storm looks like it will also be cooler, with freezing levels briefly going up to about 800 metres. Cooler temperatures will slow down the settling and bonding process for the weak layer. We were sent some interesting observations regarding conditions in what was described as "a rare BTL glade in the Hankin/Kitsequecla area." The area had a shallow weak snowpack of about 100 cm that had been weakened by the recent very cold temperatures. The observer noted "huge, widespread whumpfing, and massive settlements." This area is not very representative of conditions in most of the region, but it does make you wonder about shallow areas in the alpine that have developed due to strong winds this winter, that are getting buried by the current storm. The new storm has brought about 50 cm to the Interior. The snowpack in the Seaton Basin is reported to be 250 cm at 1650 metres, with a moderate shear down 40 cm on a facet layer. The snowpack depth in the Smithers-Hankin area is about 250-275 cm at the upper extent of the treeline elevation band. Some surface facetting has been observed above treeline, and some surface hoar observed below treeline. Very strong northeast outflow winds have scoured north and east aspects and reduced previous cornice growth. The snow has been transported into stiff windslabs on south through west aspects. These windslabs should be stiff enough in most areas that the forecast southerly winds will not be able to re-distribute the snow. The mid-december crust has been observed to have bonded to the mid-pack in most areas, but may be found to have become facetted in areas with a shallow snowpack. The mid-pack is considered to be strong and well settled in most areas. No basal weak layers of concern have been reported.