The Great 2021 Heat Wave: Sunday Updates

June 27, 2021

I’ve changed the format for the weekend…come back to this same link regularly throughout each day for quick updates as we go through the rest of this incredible heat wave.  Newest information FIRST. Remember you can follow me on Twitter: @marknelsenKPTV and Facebook @marknelsenweather

9pm Final Sunday Update

SLIGHTLY HOTTER MONDAY, THEN A DRAMATIC & WINDY EVENING COOLDOWN

Alright folks, we’ve got Portland’s warmest (hottest) night on record ahead, then slightly hotter tomorrow. Take a look at the all-time records set today. Pretty much every spot west of the Cascades in SW Washington and NW Oregon saw the hottest temp on record. Longview and Hood River numbers come in at a later time

Portland’s downtown observing location recorded a 110, which is also an all-time record. Those go back to 1874!

What’s ahead?

  1. Calm areas drop into the mid-upper 70s tonight. Windy spots only drop to 80-85 degree range…as if we’re in Arizona
  2. All model data tells us that tomorrow should be hotter than today, which is hard to believe. But it’s going to happen
  3. 850mb temps right now are around +28 to +29, and they go up to a record-breaking +31 to +32. This has never been seen in our area. Easterly flow INCREASES through mid afternoon Monday overhead, skies stay sunny. This all says several degrees of warming. I’ll stick with 114 for a high. That’ll be astounding if someone in the metro area gets within 2-3 degrees of Oregon’s all-time high (119 – Pendleton).
  4. Onshore flow sweeps up the coastline overnight = heatwave over. Then that cool air surges into the central/south Willamette Valley after noon. This should make for a cooler day south of the metro area. “Only” 95-105 south of Wilsonville-McMinnville line. Longview will also see a cooler day due to the onshore flow after about 1pm.
  5. The onshore flow will be some of the strongest we’ve seen in our area. A very shallow layer of chilly marine air surging inland trapped under a strong inversion (hot air overhead). Gusts 30-40 mph are possible 3-6pm from Sheridan to West Salem and north to Dayton. Yes, there could be a 40 degree drop from early afternoon to sunset for many of us! The cooler air arrives after 6pm in the Portland metro area, dropping us from 110+ to mid-70s by 11pm. It’s going to feel amazing…

Take a look at the WRF-GFS 5pm temperatures…112+ over a good chunk of the metro area Monday afternoon

Notice at 3pm we’ve got westerly wind beginning to pour into the central Willamette Valley. Salem is beginning to cool. Hot east/southeast wind from Longview down into the metro area

Then at 6pm things have turned VERY windy. Forecasting 8 millibars pressure difference between Lincoln City and Wilsonville! West wind gusting over 40 mph from Sheridan to Amity. Hot east wind still just barely going in the metro area. This is more of a “southwest push”; we’re not getting the real strong northwest wind coming up the Columbia River

Then at 9pm the southwesterly push has arrived in the metro area and hot east wind is gone. Gusts 20-30 mph will be ringing chimes in the southern half of the metro.

It will be a very shallow push, which means warm air overhead will mix down again Tuesday, just no extreme heat. We’ll like bounce back into the low-mid 90s Tuesday afternoon. Much better…

5pm Portland Makes It To At Least 112

High temperatures come in every six hours from the regular official reporting stations and here they are

Lots of 112s, but that’s also the current temperature at PDX. It’s possible we go a degree higher…we’ll see. Obviously that’s a new all-time record for Portland, well above the previous 108 record (yesterday) and long-standing 107 degree record. But look at the valley! Salem just blew past the 120+ year old record, by 5 degrees!

Astoria tied the 101 degree record, and Eugene set an all-time record too. I’ll have more with a detailed post about tomorrow and beyond by 8-9pm. The big message: 24 HOURS OF EXTREME HEAT STILL TO GO

3pm All-Time Record Heat, No Big Power Outages Yet

It’s 111 at PDX, the hottest temperature many of us have ever felt, including me. The same temperature as Phoenix at this hour…though at least relative humidity has fallen to 16%…it’s a dry heat. 3pm observations, notice all official stations are 108 to 111

All-time records have now fallen at PDX (again), Troutdale (again), Vancouver, Salem, and possibly Astoria where it hit at least 100. Eugene is only a couple degrees away. The Dalles at 114 is the highest I’ve seen at the airport sensor in my 30 years forecasting. The official record, I think those observations are downtown, is 115 degrees.

Huge temperature variations continue along the coastline. Just a couple miles inland it can be 105 degrees, yet around 70-75 right ON the beaches. Live view from our Shilo Inns Seaside camera shows a westerly breeze on the sand, that tells me it’s likely under 80 degrees in this spot. A lot of people. We’ve got two more hours of heating…typically. East wind has been blowing a few hours at PDX, and when that happens the temperature rise levels of a bit. That said, there’s no reason it couldn’t go up another 3-4 degrees. Hang on folks, we’ve still got 20-28 hours to go…depending on your location. I see just a thousand or so PGE customers out, that’s no worse than yesterday. Fingers crossed…

Noon

Hot…PDX is just passing over the 100 degree mark this hour. Troutdale, where east wind has surfaced, jumped to 105…at noon.

Check out Astoria…97 with a light northeast wind. Hoquiam at 100 is an all-time high temperature record.

Farther south along the Oregon coast, the extreme heat is either on the beaches or just a couple of miles inland. Example: Pacific City…67 on the beach but 97 over in the estuary area

Easterly pressure gradients continue to rise through the Gorge and across the Cascades. That easterly flow continues through Monday morning. As easterly wind surfaces in more spots, expect temperature spikes, but humidity drops. It doesn’t matter; either 102 and humid or 110 and very dry. It’s blazing hot everywhere except the beaches. Even Government Camp has gone over 90 degrees this hour.

I see PDX officially dropped to 73 degrees last night, the 2nd warmest night on record and the warmest ever in June.

10am

The heat is on big time this morning, as expected we are starting warmer and heating up much more quickly. Current temps

And regional temps

What grabs my attention right now:

  1. 850mb temp (about 4,000′) over Salem was measured at +26.4 degrees (C) this morning. About 2 degrees below all-time record. Expected to rise to a record +30 by afternoon
  2. Overnight low was bad, but we did not set an all-time record in Portland. Down into the lower 70s
  3. Easterly gradient and breezes have developed as expected. Gusts 25-35 mph at Vista House, and wherever that wind surfaces temperatures are skyrocketing
  4. It’s 100 (at two separate wx stations) in Yacolt…at 10:18am. Astounding
  5. It’s 92 already on the Long Beach Peninsula (Ocean Park). Blazing hot for some of you on the coastline the next 6 hours. Mainly north of Pacific City.
  6. PDX is 88 at 10am, already 6 degrees hotter than 10am Saturday

Hang on…it’s going to be a rough day…