Today is the Fall Equinox, which means that we are now passing into the “dark half” of the year.   Of course, due to seasonal lag it’s not quite the cold half of the year yet; that threshold is still  nearly a month away.  But normally we start seeing somewhat cooler and wetter conditions arrive around this time.

I say “normally” because not all years are normal. In fact we’re expected to see a fairly impressive warm spell beginning this Saturday, continuing through next Tuesday. A strong upper-level ridge will pop up over the West Coast for a few days.  Sunday afternoon:

That means a warmer-than-normal airmass over the region.  This is the kind of big ridge that could push us close to 100° in midsummer.  But in the last week of September, 85-90 degrees is the most likely outcome. The 12z GFS shows widespread upper 80s in Western Oregon and SW Washington by Monday afternoon:

Three or four days in the 80s would almost guarantee that September 2022 goes down as the warmest on record at PDX.

Later next week, as we approach October, we should see temps come down to something more seasonable again:

“Normal” 850mb temperatures are around 9-10 degrees C at the turn from September to October. The jury is still out on how much rain we might get, though.

I’m headed to Southern Oregon and possibly  far northern California next Tuesday-Saturday for some sightseeing.  It’s been ages since I spent any time in the Rogue Valley or the rugged highlands of Klamath County. As a kid I romanticized the climate and landscape of that region- though I imagine that climate change has lessened some of the romance.

Take care!

Karl