It will be raining the majority of the day today. In fact it may not stop raining until around noon Tuesday! We’ll chalk it up to early April showers.
In the 48 hours between Sunday and Tuesday afternoon we should receive around 30mm.
Snowpack at Zero – Very Unlikely to rise – What are the implications?
This is unprecedented in the instrument record at that site (since 1995) and as far as I have heard from other sources, unprecedented in the historic records on South Vancouver Island.
I find it very unlikely that there will be any accumulation whatsoever. The model forecasts below show no chance for below 0ºC temperatures within the next two weeks. I believe the snow season has ended on the South Island.
What does it mean to not have snowpack?
For some reason the BC River Forecast centre never released its March 9, 2015 snow survey bulletin. The last update was released over a month ago on February 23rd.
The main monthly Water Supply bulletin is due out on April 8th. That should give us a good idea of what to expect in the spring and summer months for water supplies and river flows.
So what happens if there is no snowpack on the Island?
a) If it is too warm to accumulate snow but still cool enough to keep the snowpack intact, existing snow on the ground will ‘lock in’ some of the rain… which slows down the runoff from the hills. This can keep river levels from rising too quickly (until the snowpack starts to melt of course).
b) When it snows on the hills, that water is effectively saved for when the rain stops and is released slowly into the rivers and lakes. Keeping them full into the hot and dry months of the summer.
c) As the snow melts through the summer, it keeps the rivers and lakes cold and fresh which is what the salmon and other wildlife depend on.
There are other ways the snowpack interacts with the wider environment. There is no doubt that having no snowpack to start the dry season will cause potential problems.
The best we can hope for is (sorry to say) a relatively cool and wet summer. The worst case scenario would be a summer like 2012 where we were dry from June through October and hot. If that were to happen, by late summer and fall we could have extremely challenging water situations all over the South island and very poor conditions for returning salmon.
Have a Happy Monday all.