A Chilly Evening

May 20, 2008

Snapshot Quite a change the last 24 hours…during my bike ride yesterday evening (between shows), it was in the 80s and a bit sweaty. Tonight, I needed some hardware and plants, so I was shivering a bit in the chilly/breezy air. No big changes tomorrow as an upper-level low passes overhead. It is headed for Utah by early Thursday morning. This will be our first "upper level low" event of the season. A forecasting nightmare in short. The low will back up a bit and end up in S.E. Oregon by Friday morning. As a result, showers will become widespread over Eastern Oregon Friday. There is the possibility that the showers will move west over the Cascades and down into the Western Valleys. Models don't indicate too much instability, but this pattern in the past has produced thunderstorms this time of the year in this pattern for those of us west of the Cascades.

     We'll see about that, but having dry weather in the forecast Thursday-Monday (our 7 Day forecast) is a bit risky in this pattern. Hopefully I qualified that forecast well enough during the 10pm broadcast. Either way, increasing 850mb temps means a warming atmosphere Friday-Saturday for sure. That should push temps up to or above average for this time of the year. We're getting close to 70 now for our average high here in Portland. Mark Nelsen