It’s back! The wet season has arrived; First Alert for rough morning commute Friday

I sure wouldn’t call it “spooky” weather today in honor of Halloween, but as I was prepared to head to work I sure noticed it was dark inside my house at 1pm! We had thick cloud cover overhead as a cold front moved through over the metro area. Yep, the darker time of year is about here and that includes lots of clouds, rainy periods, and cooler days. Today was our coolest day in almost 7 months with late afternoon temperatures barely creeping over the 50° mark. This could have easily been a “mild” mid-winter day.

Take a look in the rain the past 7 days; ALL of us in the metro area have received an inch and some parts of outer SE metro (Happy Valley/Damascus) have picked up more than 2.00″

and check out all those 3″+ totals in the mountains around us. Fire Season 2024 is a memory…

WHAT’S AHEAD?

Rain, and lots of it, the next two days. A cool/unstable airmass streams across the Pacific Northwest. An upper-level low (dip in the polar jet stream) sits offshore and then moves inland the next 3 days.

There will be an enhancement to the showers both tomorrow afternoon, and more noticeably on Friday morning as waves of energy rotate through the base of the trough. There have even been hints on various models and various runs that a weak surface low may develop and move inland somewhere across NW Oregon or SW Washington. The effect would be heavy rainfall at some point somewhere in the region during Friday morning’s commute. We may also see southerly wind gusts in the 35-50 mph range for a couple of hours during the morning commute, mainly from south metro down into the Willamette Valley. This would drop a few tree limbs into powerlines in spots = power outages. In much of the metro area a dying easterly wind will likely be hanging on, keeping the southerlies from getting too strong. Our evening GRAF model is a bit stronger than earlier runs; not a windstorm, but plenty of wind during the Friday morning commute south of Portland.

There’s a good chance we double the last week’s rain totals in the next two days. That’s 1-2″ rain in the western valleys! If we already had saturated soil in mid-winter and rivers running high, that might be a problem for local flooding by Friday afternoon. But since the soil is still relatively dry, all our trees/shrubs/lawns will be soaking up that much-needed rain. Of course 1-2″ rain spread out over 2 days is okay, but if we get 1″ of rain in just a few hours, that can cause urban/local flooding issues. The same model shown above is producing about 1.00″ of rain in both Salem and Portland between midnight Thursday night through the end of the Friday morning commute. Plenty of that will fall BEFORE the commute, but even 1/2″ rain plus a breezy southerly wind will make for an annoying first commute of November! For this reason we’re calling Friday morning a FIRST ALERT WEATHER DAY (MORNING). Not a major storm, but it WILL have an impact on your life. That’s especially if you lose power from the gusty wind!

MOUNTAIN SNOW

It’s not unusual to see snow down to the passes in late October or early November, but each year is VERY different. Take a look at November 1-15th snowfall at Government Camp the last 30 years. Some years no snow falls, other years several feet accumulate and the ski season kicks in early. Last year none fell in the first two weeks of the month.

The snow level lingers near or above the passes these next two days with all the showers. I expect 6-10″ at Government Camp, and 12-18″ up at the higher Mt. Hood resort slopes (5,000-6,000′). WAY up there around 6,500′ and above, 20-30″ will fall. If you are driving across the passes the next two days, mornings will likely be snowy but then expect mainly slush or wet roads midday and afternoons. Santiam and Willamette passes are a bit higher so snow coverage will linger further into each day there.

MILDER AND DRIER NEXT WEEK

Another weak upper-level trough slides through Saturday for lighter showers, then IN GENERAL we’re headed into a setup with ridding nearby or just offshore. That makes for weak weather systems or dry weather. You can see the higher-than-normal heights in this 7-day average from the Euro ensembles next week

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