rain

9pm Wednesday...

Now that was a soaker during the evening commute. A strong Pacific frontal system moved onshore the 2nd half of today, bringing gusty wind to the coastline and heavy rain to many areas.

Peak wind gusts along the coast were generally 40-55mph in the cities. The usual highly exposed spots saw gusts over 70 mph. A 76 mph gust at Cape Foulweather and 75 mph at Barview Jetty just west of Garibaldi are the highest I've seen. Those southerly winds died down after the cold front passed. But just this hour a westerly wind gust of 69 mph was reported at a temporary IRAWS weather station on the Lionshead Fire southeast of Breitenbush Lake. Luckily it's raining with high humidity and temps in the 40s too!

During the evening commute a few areas saw buckets of rain. Aurora airport picked up 0.52" between 5-6pm. Troutdale saw .39" at the same time. Here are metro totals as of 8pm

The 0.68" in Portland so far today makes it the wettest day since mid-March! That's only as of 8:30pm. It's quite possible we go above the .74" on March 14th and see our wettest day since late January. Spring was relatively dry. Similar to Friday's thunderstorms, some spots have been a bit wetter today...

What's Ahead?

  1. Expect two more wet days, then just a few sprinkles/showers Saturday
  2. A long dry spell begins Sunday
  3. September ends and October begins warm, sunny, & dry

Tonight's cold front was the first of three organized system moving through the Pacific Northwest. The 2nd arrives Friday morning, then a very weak ripple in the jet stream comes through here late Friday night and Saturday morning. The upper-level pattern shows a cool trough offshore that will rotate by to our north the next two days; (click for a better view)

How much MORE rain can we expect? Quite a bit for late September. Here's one model's forecast...shows maybe another 0.50" or so in the valleys and 2" additional in the mountains. This is excellent for the leftover smoldering Riverside and Beachie Creek fires; there won't be much left of them. East side of the Lionshead fire will not get as much rain so it'll keep limping along.

By Saturday a weak upper-level ridge has begun to show up, but it's slower to get its act together and that's why we've kept a few showers in that forecast

But check out Monday! Huge and hot upper-level ridging returns over the West Coast. 500mb heights up above 594dm! One month ago we'd be going for mid-upper 90s. BUT, it's the end of September and unlikely we'd hit 90 in this setup.

By Thursday October 1st, it is STILL there. This is the ECMWF ensemble average...the average of 51 ensemble members. West Coast ridging and cold fall weather across eastern USA.

The brand new GFS ensembles (should do better this winter) look the same for next Thursday, although slightly weaker

The main message is that we're headed into an unusually warm and dry period for all of next week, starting Sunday. The extended WRF-GFS cross-section shows a (more typical) east wind episode begins Tuesday. I've circled the wind forecast up around 2,000-4,000'...dry and warm

At this point I'm not too concerned about another widespread fire episode since Cascade forests will have been doused with 2-5" of rain over the previous 10 days. It'll be early October too...long nights and inversions in the valleys = less time for a fire to burn actively each day.

Alright, that's it for tonight. Enjoy the rain the next few days; you look forward to some beautiful blue skies and warm temperatures next week.

Chief Meteorologist Mark Nelsen

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