August was a strange month compared to recent years. First scorching hot, then a rare two-week period of below-normal temperatures with occasional showers. Average temperatures for the whole month were normal.

What’s next?

• The last three days of August will be hot; Temperatures will reach a high of 96-99 degrees in the metropolitan area on Saturday.
• Humidity on Thursday and Friday will be lower than ever before in hot weather this summer. A dry heat.
• The windy east wind in the metropolitan region on Thursday will ease on Friday and Saturday
• Thursday and Friday are not First Alert Weather Days because it is not too hot and the nights are pleasant.
• We’re calling Saturday afternoon a First Alert Weather Day because it will be particularly hot and humidity will return to normal.
• There are NO heat warnings/advisories from the Portland National Weather Service…This is not “dangerous” heat.

Our forecast for this late heatwave in Portland

Of course, as with all heat waves, there is a hot ridge of high pressure over the region. The highs are not incredibly high, just reaching 590 dm at 500 mb, but warm enough to get us into the 100s with a light offshore current. The view from now until Saturday afternoon is about 18,000 feet.

The figures forecast above are not quite record levels, but close

Offshore flow is relatively weak, but we have a strong enough thermal trough west of the Cascades to push the northern Oregon coast above 80 degrees on both Thursday and Friday…possibly temperatures up there will still be above 80 degrees early Saturday before the southwesterly/cooler winds move in. The lower values ​​will be for cooler Central Coast cities (Florence, Newport, Lincoln City).

We decided to make Saturday a First Alert Weather Day, in part because it looks like the weak offshore flow in the metro area will continue late into Saturday. There are signs of a light westerly wind Saturday morning in the central/southern Willamette Valley. That should temper the heat there a bit, and the GRAF model is consistent with that. By the way, those are thin high clouds; the model shows them a bit thicker; that’s a known problem.

The dry easterly flow on Thursday means that dew points will drop to over 30 degrees tomorrow and linger in the 40s on Friday. We haven’t experienced such pleasant dry heat since early summer. That allows all of us in the west to see temperatures drop to 50 degrees by Friday morning.

WHY IS THERE NO FIRST ALERT DAY ON FRIDAY?

1. Because a maximum temperature of 95 degrees or below hardly changes our lives in this climate.
2. Friday will be particularly dry, with temperatures starting at 10 degrees, meaning we’ll be between 21 and 25 degrees for most of Friday… hardly a really hot day.

Let’s face it folks, we started calling really impactful weather days “First Alert Weather Days” in the fall of 2022. I like the basic idea of ​​highlighting certain weather days on our graphics to get your attention. Since then, two other local TV stations have mimicked this with a sort of scary red on their 7-day forecasts (and others). I certainly don’t want this to be a “race to the bottom” for meteorologists trying to predict more and more “days”. I/we intend to ONLY predict these days WHEN IT’S REALLY A BIG DEAL weather-wise. Too many “alert” days and you, the public, will be crying “weather wolf”. For example, I saw “dangerous heat” on a graphic somewhere else tonight. There’s nothing DANGEROUS about the next 3 days… it’s going to get extra hot one day… that’s all. You can count on us to let you know when the weather gets really dangerous AND to let you know when it’s not so bad..

By the way, a weak low pressure system will move through Sunday night into Monday, bringing MUCH cooler temperatures, clouds and maybe a few showers on Labor Day…there’s something for everyone this holiday weekend. Enjoy!

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