A short blog post tonight! Just to point out how quickly the snow/water situation is going downhill as this warm-ish and VERY DRY spring continues…
Snowpack on April 1st…pretty good across Northern Oregon, below average across the southern half of the state
Today…what a change! Much worse. The extremely dry April and warm temperatures have taken a big toll
Now it’s important to point out that early & end of season maps can be deceiving. For example there are many lower elevation stations that don’t typically still have snow on the ground in early May. That could skew the average. But the point is that things are heading downhill quickly and I don’t see any change through mid-May. Take a look at the Mt. Hood Test Site near the bottom of Pucci lift at Timberline (5,400′)
The GREEN line is the typical accumulation of “snow water” through the season. The colored areas represent lowest to highest snowpack on record on any one date. Green area is an “average” year. At this elevation, the abundant February snows brought the snowpack up well above average (BLACK line). And a cool March preserved that snow. However the lack of precipitation in March means a peak occurred a bit earlier than normal. Now it has slipped below average! Basically A GREAT SNOWPACK IN LATE FEBRUARY AND EARLY MARCH IS NOW MELTING FASTER THAN NORMAL. The whole snowmelt season is earlier and more condensed this year. At this rate there won’t be snow on the ground more than another month…unless we go back to cool and wet weather.
Farther east, in the Blue Mountains, this site shows something similar…well above normal snowpack in March, then a rapid melt right now. It’ll be gone in a couple days…earlier than normal!
This spells trouble for our water supply. In fact Willamette Valley Project reservoirs are running well below where they should be in late spring. Most of these lakes reach their maximum “full pool” level at the end of the spring filling season. That’s right now. But two months of very little rain is a big problem.
Detroit Lake (one example) is about 17 feet below where it should be.
So…we need rain, but I don’t see anything significant through the next week. I’ve never seen it this dry at this point in the spring.
Chief Meteorologist Mark Nelsen