Another sunny and warm day today…66 here in Portland for the official high today. Today was our 5th day in the 60s (or 70s), and it appears we have at least 4 more. Many years we don’t see a warm and dry stretch that long in the month of April. Take a look at the sunset this evening!
Photo by Michael Trofimov. One more picture came in today from Gene Blick, showing a nearly snow-free Lost Lake basin:
As I’ve mentioned a bunch of times during the late winter and early spring, we’ve had unusually low snowpack below about 4,000′. Luckily the northern Oregon ski areas had enough snow in February and again in later March to prolong the ski season a bit. Both Mt. Hood Skibowl and Hoodoo Ski Area have their final weekend coming up; both will be closed for the season after Sunday. Mt. Ashland was never able to open this season for the first time in its history. Of course higher up on Mt. Bachelor and Mt. Hood the end of the ski season comes later. Interest sure wanes at the ski areas in April, especially when we have such terrific weather in the lowlands. I know it really annoys the ski area operators since they always have more snow on the ground in April and May than early on in November when just about everyone tries to get up on the slopes. Then, this time of year (in a normal year) there is plenty of snow but interest totally drops off. I have the feeling the reason is that in November/December it’s usually wet and always chilly outside, so why not head up to the snow and enjoy it? But we have limited warm weather and sunshine around here in the lowlands so when it finally shows up in spring we want to do all the things we couldn’t do in the winter. Like bicycling, running, hiking, golfing, gardening etc… Maybe it’s really just the opposite of November; there is pent-up demand to get outside and do things in the lowlands this time of year so snowplay in the mountains seems so…winterlike.
Okay, enough about that. Let’s move on to the forecast.
No big changes the next 4 days as upper level ridging builds along the coast and then shifts inland Sunday. When that happens Sunday, we’ll see a “thermal trough” develop along the coastline with easterly wind from the Cascades all the way to the beaches. That means one very warm day…probably into the 70s out there too!
Of course we’ll be much warmer here in the valleys as well. I think MOS temperatures (derived from model information) are too cool with high temps right around 70 degrees. Just as in the winter, I think they are allowing too much cool air down into Eastern Washington and Oregon. My April temperature chart shows an 850mb temperature around +9 (models agree on this) with strong easterly flow should give us a high temperature between 74-78 degrees. Up until the 00z GFS, models have been showing a big marine push Monday afternoon as an upper level trough approaches the Northwest. The 00z GFS splits that trough, prolonging the warm weather and possibly giving us temperatures closer to 80 Monday. It IS the GFS, so I ignored it and went with the ECMWF for making my 7 Day forecast.
Beyond that, cooler and wetter weather comes back, although I don’t see an unusually cold and wet pattern. Take a look at the 12z ECMWF ensemble chart, showing temperatures at about 5,000′ over Oregon over the next 10 days:
Notice the long period of near average temperatures after the warm period Sunday-Monday.
Enjoy the sunshine this weekend! I plan to clean up the last of the ice storm mess (flames!) in my yard from early March, take a long bike ride, and soak in some rays.
Chief Meteorologist Mark Nelsen