The Great 2021 Heatwave: Monday Updates

June 28, 2021

I’ve changed the format for the heat wave…come back to this same link regularly throughout each day for quick updates as we go through the rest of this incredible weather event.  Newest information FIRST. Remember you can follow me on Twitter: @marknelsenKPTV and Facebook @marknelsenweather and I’ll be on TV tonight at 4, 5, 6, 8, 9, 10, 11.

11pm Final Update

This must be just about the largest temperature swing we’ve seen from a marine push. 46 degrees cooler at Salem at 11pm compared to the 117 degree high. By the way, Salem tied Palm Springs today, and was only exceeded by Death Valley here in the USA.

9pm Major marine push = much cooler

The past three hours have featured a very strong marine push. Just about the strongest I’ve ever seen and it’s wonderful! This means a shallow layer of ocean air surged inland. We expected that to happen and models forecast it very well. Most of us have seen a 25-30 degree drop. Kelso has dropped 41 degrees! That’s 110 down to 69 in about 4 hours. That’s some serious free air conditioning. I’ve had a few people ask me what’s up with the haze? I think it’s from some large fires burning just across the California/Oregon border that was picked up as air surged up from the south. By the way, Portland reached 116 around 6pm. These will now be the three hottest temperatures in Portland’s history. Downtown made it to 114.

6pm

Today’s forecast worked out perfectly…in a bad way. Marine air is arriving too late to keep us from setting more all-time records in the north Willamette Valley. Here are the official highs. Notice Salem was within two degrees of the all-time Oregon high (119 Pendleton-1898). The Dalles (technically in Dallesport, WA) has tied the all-time Washington high temperature record of 118

Portland’s 115 degree high beat the old (pre-Saturday) record of 107 by 8 degrees! Downtown hit 114, beating that old record by 7 degrees. Basically this heat wave blows away all other heat waves and resets the historical record

Cooler air continues to flood into the western valleys with wind gusts 30-35 mph west of Salem and up toward McMinnville. The cooling has reached a Bald Peak to Aurora line on the south, and down to Scappoose to Woodland coming in from the north. The next two hours we’ll see a 10-15 degree drop in the metro area as the east wind disappears and is replaced by the southwest or northwest wind. By 10pm I expect most of the metro area to be in the 70s…get those windows open later!

That’s it for now…I’ll be on FOX12PLUS (Channel 13 or 49) 8-10pm, then back on FOX12-KPTV 10-11:30pm. See you there!

2pm

Salem has broken their all-time temperature record AGAIN this afternoon. 116 degrees at 2pm!

This is just ahead of the approaching marine air. 112 at PDX ties the all-time high once again. We are running 3 degrees hotter than yesterday at 2pm. Headed for at least 114 the next few hours. Marine air is flooding inland on the west side of the valley; it should make the big move now to 5pm. Regional temps…The Dalles is at 115, just 4 degrees short of the Oregon all-time record. Except “The Dalles” is the airport…across the river in Washington.

Hang on folks…much cooler air begins arriving just 4-6 hours from now…

I’ll be on TV from 4-7pm as we track the extreme numbers and cooler air arrival

11am Monday

It’s the last day, but this heatwave is going out with one last blast of hot air. That will finish out this (hopefully) once-in-a-lifetime event. I would not be surprised to see one of the official Portland area weather stations hit 116 degrees.

Everything is proceeding according to plan. We’ve got 2-3 millibars (hot) easterly gradient still going through the Gorge to keep the extreme heat going through maximum heating around 5pm. Cooler marine air is poised in the Coast Range and pressure gradients are building between the coast and Willamette Valley. It’s 74 just west of Willamina, but 103 in Sheridan! Eugene is running noticeably cooler too. Hard to believe at 11am we’ve got temps well above 100 in a good chunk of the metro area.

And the regional temps.

850mb temperatures over Salem was a bit below the forecast this morning, at 28.0 degrees…we will see if the “coveted” +30 shows up in the afternoon balloon sounding.

Portland only dropped to 76 this morning and that is a new all-time record. But wait, there’s more. Many areas where it stayed breezy remained in the 80s! At my home it was 90 or higher all the way until 2am. I see a hilltop in Damascus only briefly touched 89 degrees before the sun rose.

Again, this is likely a once-in-a-lifetime occurrence. By the way, that record only stands if PDX stays at/above 75 degrees through midnight. It’s possibly the big surge of marine air heading inland this evening drops us below the mid 70s by that time.

Chief Meteorologist Mark Nelsen