There has been a substantial increase in our snowpack during November. To illustrate, here are the snow depths on November 1 and last night. Notable increases, particularly over the north Cascades and southern BC..
But even with increases, the snowpack is less than at the same time last year (see below).
In fact, although there have been considerable increases in higher elevation snowpack the past few weeks, the latest USDA Snotel data shows that the Cascades are still below normal (about 40%), while the northern Sierra Nevada is above normal, as are the western slopes of the Rockies.
The last day has not been kind to our mountain snowpack, with warm, rainy conditions caused by a moderate atmospheric river. But that is past now and we have been experiencing cooler, unstable conditions, with decent snow showers in the mountains.
The forecast for the next 72 hr (ending 4 AM Saturday), suggests another half a foot at higher elevations in the Washington Cascades and huge snow dumps over northern CA and southern Oregon.
Now modern ski areas have considerable capabilities for making snow if the temperatures are cold enough, and there is good news on that front--we are heading into a period of much cooler lower atmosphere temperatures.
To show this, here are the NOAA/NWS GEFS ensemble air temperature forecasts at the surface for Stampede Pass in the central WA Cascades around 4000 ft (remember that in an ensemble system we run the forecast model many times to explore uncertainty). The black line is the average of the forecasts, the ensemble mean, which is usually a very good forecast. Temperatures really drop the next few days and generally stay below freezing. Any snow won't be melting and snow making should be fine about 3500 ft.
from Cliff Mass Weather and Climate Blog https://ift.tt/2AsU4rA
No comments:
Post a Comment