An unseasonably warm and dry winter has left the BC mountains with a little as half the normal snowpack for this time of year with little prospect it will change before spring.
Summary:
Feb 1st snow bulletin is now posted. Sampling of whole provincial network will not occur until the March 1st period, but there is now sufficient sampling information to identify the trends around the province. Of interest are the extremely low snow packs in the Upper Fraser and Similkameen basins and at low and middle elevations throughout the province. There is a significant area of the north central interior bounded by the Bulkley River Basin in the northwest to the West Chilcotin in the southwest to the Upper Fraser and Mcgregor Rivers in the north east and the Valemount area in the southeast, that is extremely low on snow pack. This area is in the 45% to 60% of normal snow pack range at upper elevation with a number of new record low measurements. Likewise the Similkameen River Basin is showing some period of record low snow packs. All areas of the province are showing below normal snow packs for the period. As two thirds of the mountain snow pack is normally on the ground by February 1st it is unlikely the current trend will be reversed. Assuming normal weather conditions for the remainder of the winter and spring, mountain snow packs can be expected to peak at below normal values this season. Snowpack After a very late start to snow accumulation, mid and upper elevation snowpacks throughout BC still vary from below to far below normal for February 1. The Upper Fraser, and Similkameen have around half of their normal snowpacks. Most of the rest of the province is in the 60% to 75% of normal snowpack range, with Vancouver Island and the far north in the 80% to 90% of normal range. Due to generally well above normal temperatures over the last three months, lower elevation snow nearly everywhere is shallow. One example of this is the low-elevation Fraser snow water index, which has improved but is still very low at 41% of normal for this date. Weather As indicated by Environment Canada valley bottom weather stations, weather all over the province has been much warmer than normal since November. January mean monthly temperatures varied from 2 or 3 degrees C above normal on the South Coast and far northern BC, to around 5 degrees C above normal in central areas. Cumulative precipitation since November has beengenerally less than normal through most of the province, with the exception of the far north, where heavier January snowfall now has winter precipitation totals at near to above normal. Outlook By February 1 each year, on average two thirds of the peak snowpack for the winter has fallen. This means that the weather patterns during the next three months or so still can have a significant effect on this year’s maximum snowpack. However, if this winter’s El Nino (drier & warmer) conditions persist through the remainder of the winter, freshet volumes will probably be below normal this spring.