8pm Thursday...

You just made it through ANOTHER 100 degree day in Portland. PDX hit 102 yesterday, and 103 today. You see the entire metro area was in the 103-107 degree range. This would be our big summer heatwave…if it weren’t for the historic event back in late June that produced 108-116 temps at PDX. What a summer…

Highs Today Metro.png

And the official numbers across the region

Highs Today DMA.png

Off the map, a gusty northeasterly wind reached Bellingham, Washington today. That pushed the temperature to 100 degress…an all-time high! The airport there is located very close to the water so most afternoons a cooling onshore breeze keeps the extreme heat away. Not today; summer 2021 will be remembered for a long time all across the region. Notice a bit more onshore flow at the beaches = no heat there. A bit cooler than yesterday at Astoria and Tillamook.

For the hardcore weather geeks, I see the 850mb temperature on the afternoon balloon sounding over Salem was +25.8 degrees (C). That’s very near what used to be the all-time record…this is a hot airmass! There was about 1 millibar of easterly flow through the Gorge earlier today and some light easterly flow was blowing over the Cascades. That was just enough to warm us up a bit from yesterday. That easterly flow delivered a first batch of lowland wildfire smoke to the Portland metro area.

Here’s the current view from our Skyline Camera; not really a “postcard-perfect” moment in the Rose City is it? You can’t see more than about 15 miles; Troutdale and Gresham are out there…somewhere

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Current AQI shows parts of metro area and Gorge into the “UNHEALTHY” category; not so bad up north at Longview and in the Willamette Valley.

airquality.PNG

I want to alleviate any renewed anxiety about us having another “SmokePocalypse” similar to last September

1. There are no huge fires close by to produce massive volumes of smoke

2. Flow goes westerly the next few afternoons = dense low level smoke shouldn’t get stuck in the valleys

3. It’s not September, when it’s much easier to get inversions and smoke lingering

4. Westerly flow returns at all levels of the atmosphere Sunday = much better later that day and next week

Check out the HRRR smoke modeling forecast. First, right now. Notice the colors (generally) match the Air Quality Index categories:

HRRR Surface Smoke Forecast.png

Then by tomorrow morning an even thicker surge of smoke has arrived at the eastern end of the Gorge. Really bad air Hood River, The Dalles, and farther east. But not much worse in Portland

HRRR Surface Smoke Forecast8am.png

Just in time, we switch to a light westerly flow tomorrow afternoon west of the Cascades. That pushes the thickest smoke over and east of the Cascades…at ground level. There will still be a sickly, yellowish sun overhead. Notice the model thinks the Tillamook forest fire will produce significant smoke; that seems unlikely.

HRRR Surface Smoke Forecast10pFriday.png

By midday Saturday, a continuing (light) westerly flow is keeping most areas west of the Cascades in good shape, and west wind in the Gorge is helping a bit too. On Sunday I expect more westerly flow and even better conditions

HRRR Surface Smoke Forecast11amSaturday.png

Remember these are GROUND LEVEL forecasts, there will still be lots of smoke swirling overhead many thousands of feet up.

As for temperatures, the strong upper level ridge remains over us tomorrow and Saturday.

ecm_friday.png

Then weakens with two cool upper-level troughs passing by both Sunday night and midday Tuesday. This returns us to a more typical morning clouds and afternoon sun routine. High temps drop back to around 80…much better!

By the way, Portland only dropped to 70 degrees this morning, which makes it an ALL-TIME RECORD WARM NIGHT FOR THE MONTH OF AUGUST.  Tonight should be similar

Forecast Night City Temps.png

Salem now has a new record for the month too… at 69 degrees. The days of “you don’t need air conditioning in Portland” are over aren’t they? Take a look at this. The number of nights at/above 65 degrees at PDX for each decade. I had to skip one year to get these past 10 years…didn’t want to miss 2021.

65 Degree Nights Climate Portland.png

Wow! What a change the past 10 years…of course in general a warming urban area is going to see warmer nights as the decades go on. But the past 10 years have been amazingly warm. Here’s the deal, clearly a large part of this IS the urban heat island. But some is our warming climate as well. I checked Salem, Eugene, Olympia (using both 60 and 65 as a cutoff) and can’t find a similar effect. Yes, nights are a bit warmer, but nothing so dramatic as what we’re seeing in Portland.

That’s it for now, I’ll be on at 8pm & 9pm (PDX-TV), and 10/11pm (KPTV). I’ll see you there.

Chief Meteorologist Mark Nelsen

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