PORTLAND, Ore. (KOIN) — Prepare for excessive heat, dry and windy conditions with fluctuating air quality this weekend.
The day starts off clear with temperatures in the low to mid 50s in the valley. Astoria is on track to have the coldest morning temperatures again after breaking a record low temp Thursday morning at 44°. The old record was 45° (1955). You’ll notice the beginning of the overall warm-up today. The valley will see highs in the mid to upper 80s. Offshore flow (wind from the east) develops this afternoon. As a result of this wind reversal, coastal temperatures could reach 80 today.
Excessive Heat Warning goes into effect Saturday and lasts through Sunday across the Willamette Valley, including the Columbia River Gorge. Hot hot, just hot – low 100’s possible. This will come as a shock considering this August so far has been, shall we say, bearable. We’ve had one day at 90+, seven days at 80+, and 5 days at 70+. Normal daytime high in Portland is 82 for mid August.
What about last year, wasn’t it hot then? Let’s examine similar calendar days to this weekend. August 15th, 2019 was 83 degrees. August 16th, 2019 was 77 degrees. There were zero days in August last year meeting or exceeding 100 degrees. The all time record at PDX for the 15th day of August is 100 degrees (2008). The record for the 16th is 102 degrees (1977).
On Sunday a southerly flow kicks into high gear, dragging up clouds and moisture from the south. The chance for non-severe thunderstorm development seems low right now but it cannot be ruled out yet. The one thing we don’t want are dry thunderstorms and that may be the more likely scenario leading into Sunday.
Mosier Creek Fire:
Concerns moving forward: gusty each afternoon & evening. Wind today swings around from the NE pushing smoke to the south and southwest. Saturday directly from the east pushing smoke toward Portland, potentially. Sunday wind from the SSW pushing smoke to the north across I-84. Yes, it will be hot there too around 100.