4 out of the past 6 Octobers have been wetter than normal here in Portland as mentioned in a previous post:
As of 6pm Tuesday we haven’t seen all that much rain today.
The sunbreaks around 5pm sure did make for this beautiful rainbow from Joanna Burn up in Vancouver!
The rain action should pick up dramatically overnight through midday Wednesday as a low pressure system tracks directly over NW Oregon. Here is the 8am view from WRF-GFS model:
The surface low appears to move right through an Astoria to Portland line in the first half of the day. The showers taper off beyond that time and Thursday looks mainly dry.
Other than a warm front brushing us Friday and the early part of Saturday, the jet stream should lift north for a few days putting us on the very warm side of the jet stream. We will be just south of an “atmospheric river” of subtropical moisture aimed at Vancouver Island and NW Washington. As a result our forecast highs of 70 & 73 for Saturday/Sunday could be quite low. We may end up closer to 80 if the clouds clear out both days.
Beyond that there is good agreement that we’ll see our first “stormy” period the latter half of next week. Check out the deep upper-level trough and strong westerly jet on the ECMWF for next Thursday…looks more like November doesn’t it?
The GFS and GEM models keep the ridging over us a little longer next week, we’ll see how that pans out. It’s definitely a warm pattern, much milder than the past week. The 18z GFS is very warm with a bunch of 70s Saturday through Wednesday.
If so that’ll be nice after the icy cold September! Okay, a degree or so below normal, but I want to keep everyone happy…
Chief Meteorologist Mark Nelsen