What a change this afternoon. Take a look at the temperature change from 6pm Monday to 6pm Tuesday:
We were 23 degrees lower here in Portland! Around noon I was doing some errands on the eastside of town, getting irritated at the lack of rain (I don’t like a bad forecast). But that forecast turned out perfect this afternoon…what a downpour. It was our first good soaking in about 4 weeks, very much overdue:
The cold upper level low has definitely arrived hasn’t it? 850mb temps over Salem this afternoon were measured between -2 and -3 degrees celsius. That’s just about the core of the cold air, so it won’t get any colder than this. The bad news though is that the upper-low isn’t going anywhere from now through Monday (Memorial Day). That means we have a chance for showers through the Memorial Day Weekend. The coldest/heaviest showers will definitely be tomorrow through Friday with the coldest airmass.
If you are looking for a return to some semblance of warmer weather, think again. Take a look at the 850mb ensemble temperature chart from the 12z ECMWF:
Very good agreement that below average temperatures will likely continue for the next 10 days. Monday and/or Tuesday will be close to average, but at that time we get into a wet westerly flow, so lots of gray.
Here’s the 00z GFS chart, very similar:
So put away the shorts & flipflops, keep the pool covered, and hope your warm weather veggies can tolerate some repeated soakings without rotting.
Chief Meteorologist Mark Nelsen
Posted by Mark Nelsen 
