Historic Pacific Northwest Heatwave of 2021

[Roger Smith]

4 hours ago, LibertyBell said:

I dont regard high min temps as "hot"- most of my most memorable heatwaves had high temps of 100 or above like  1991, 1993,  1995, 1999, 2010 and 2011.

That aspect was covered in the previous post to the minima. The point is that mean temperatures are an average of ,max and min, so I am interested in understanding how record high mean temperatures will be affected by differential changes over time in max and min. The study of mean temps has not been posted yet. 

[Roger Smith]

1 hour ago, bluewave said:

 

 

I disagree to some extent that this is just a bell curve shifter, it's a singularity and there was nothing in the June climate records within 5-6 deg of this on a regional scale, so the shift is more to do with a longer season than a former climate moved over to the right, in my opinion anyway.

I am right under the H today, very close to the station "Warfield" in the Trail area listed in Don's report above. 

Just in from a morning walk and would say it is well over 95 F at 1100h local time, feels oppressively hot out of the shade. Thank goodness we have very little humidity this far inland, the situation is probably quite a bit worse in the large cities near the coast because they are getting moderately high dew points in the 60s, here it's more like 50F. 

Some were commenting on the amount by which daily records had fallen yesterday. Part of that is simply that June 27 didn't produce any real heat in past years although I see Warfield was only slightly over a 2015 record. Other dates a little later into the summer would have had narrower margins for these records. The same will happen today. Also just because it gets hot in this region is no guarantee that coastal locations will set records, in some heat waves they hold on to sea breeze or marine layer conditions, as shown in coastal Oregon where the southern half of the coast stayed quite moderate while Astoria got up to 101 with a land breeze. In this heat wave the severity is overwhelming the sea breeze protection, the Straits of Juan de Fuca and Georgia are turning into the Sea of Cortez del Norte with coastal 40 C and over water 25 C readings. The outer coast of Vancouver Island still has some locations in cooler marine layers and probably dense fog as water temps out there are only in the 50s to low 60s F. 

Will not be surprised if our new national record lasts only one day and gets replaced today. Warfield is not quite as rocky a location as the three traditional record setting spots (Lytton, Lillooet and Osoyoos north of Omak WA), but it does heat up with a southeast exposure and keep in mind this thermometer is 400 feet above the Columbia River where Trail, BC is located; I often notice on car thermometers that it is 1-2 C warmer in Trail than in Warfield, it is very rocky around Trail partly because the smelters there killed off the first growth of the forest cover and what they have since improvements were made resembles a Utah open woodland setting without large trees. 

Working on part three of that study of mean temps, we'll see if it overlaps the maxima or the minima better. 

[donsutherland1]

The 6/28/2021 12z sounding (500 mb heights):

[bluewave]

21 minutes ago, Roger Smith said:

I disagree to some extent that this is just a bell curve shifter, it's a singularity and there was nothing in the June climate records within 5-6 deg of this on a regional scale, so the shift is more to do with a longer season than a former climate moved over to the right, in my opinion anyway.

The Hansen, Sato, and Ruedy paper expanded on the changing nature of these extreme heat events as the climate continues to warm.

https://skepticalscience.com/Summary-of-Hansen-Nov-2011.html

The New Normal 

From 1950 to 1980 normal temperatures, cold and hot are all present about 33% of the time as expected.  There is little Very Hot or Very Cold. The Nauties are completely different.  Normal and Cold have dropped to 20 and 15% respectively and Hot has risen to about 66%.  In 2010, Very Hot (+2σ) occurred over 31% of the Earths surface and Extremely Hot (+3σ) occurred over 13% of the Earth’s surface, while the corresponding Very Cold and Extremely Cold were 1% and 0%.

Hansen says: 

“The most dramatic and important change of the climate dice is the appearance of a new category of extreme climate outliers. These extremes were practically absent in the period of climatology, covering much less than 1% of Earth's surface. Now summertime extremely hot outliers, more than three standard deviations (σ) warmer than climatology, typically cover about 10% of the land area. Thus there is no need to equivocate about the summer heat waves in Texas in 2011 and Moscow in 2010, which exceeded 3σ – it is nearly certain that they would not have occurred in the absence of global warming. If global warming is not slowed from its current pace, by mid-century 3σ events will be the new norm and 5σ events will be common.”

Looking at Figure 3, we see in 2010 that Moscow was in the middle of a large black spot of +3σ, while in 2011 Texas was in the middle of a similar spot.  Europe had its time in the heat in 2003.  All these outliers were absent from 1950-1980.  People who continue to deny that extreme heat is caused by AGW need to look carefully at these graphs.  These extreme weather events were not normal; they are directly caused by AGW.  They are becoming normal now.  In 2010, 17% of the world’s land area was Extremely Hot (data not shown).  In the 1960s there were virtually zero Extremely Hot areas.

[TimB]

Seattle hit 102 before noon, so has a very good shot at breaking its all time heat record by 1pm. I wonder what the earliest time of day is for a location to break its all time heat record.

[sojitodd]

23 minutes ago, TimB84 said:

Seattle hit 102 before noon, so has a very good shot at breaking its all time heat record by 1pm. I wonder what the earliest time of day is for a location to break its all time heat record.

And Portland has hit 105 before noon as well. They are now at 108 shortly after noon. Seattle somehow went back to 99.

[GaWx]

Noon PDT vs 24 hours ago:

Portland 105 (+7)

SeaTac      102 (+8)

Pendleton 105 (-1)

Walla Walla 105 (+2)

Spokane 98 (+3)

Yakima 104 (+3)

[donsutherland1]

42 minutes ago, bluewave said:

The Hansen, Sato, and Ruedy paper expanded on the changing nature of these extreme heat events as the climate continues to warm.

https://skepticalscience.com/Summary-of-Hansen-Nov-2011.html

The New Normal 

From 1950 to 1980 normal temperatures, cold and hot are all present about 33% of the time as expected.  There is little Very Hot or Very Cold. The Nauties are completely different.  Normal and Cold have dropped to 20 and 15% respectively and Hot has risen to about 66%.  In 2010, Very Hot (+2σ) occurred over 31% of the Earths surface and Extremely Hot (+3σ) occurred over 13% of the Earth’s surface, while the corresponding Very Cold and Extremely Cold were 1% and 0%.

Hansen says: 

“The most dramatic and important change of the climate dice is the appearance of a new category of extreme climate outliers. These extremes were practically absent in the period of climatology, covering much less than 1% of Earth's surface. Now summertime extremely hot outliers, more than three standard deviations (σ) warmer than climatology, typically cover about 10% of the land area. Thus there is no need to equivocate about the summer heat waves in Texas in 2011 and Moscow in 2010, which exceeded 3σ – it is nearly certain that they would not have occurred in the absence of global warming. If global warming is not slowed from its current pace, by mid-century 3σ events will be the new norm and 5σ events will be common.”

Looking at Figure 3, we see in 2010 that Moscow was in the middle of a large black spot of +3σ, while in 2011 Texas was in the middle of a similar spot.  Europe had its time in the heat in 2003.  All these outliers were absent from 1950-1980.  People who continue to deny that extreme heat is caused by AGW need to look carefully at these graphs.  These extreme weather events were not normal; they are directly caused by AGW.  They are becoming normal now.  In 2010, 17% of the world’s land area was Extremely Hot (data not shown).  In the 1960s there were virtually zero Extremely Hot areas.

IMO, that's a landmark paper that retains its value today. To put things into perspective, the 102-degree reading in Seattle is just over 3.4 sigma over the 1991-2020 average summer maximum temperature. It would be nearly 3.65 sigma over the 1951-80 numbers. In sum, that event is more than twice as likely (nearly 2.35 times as likely) in today's climate as it was in the earlier climate regime.

[sojitodd]

2 minutes ago, GaWx said:

Noon PDT vs 24 hours ago:

Portland 105 (+7)

SeaTac      102 (+8)

Pendleton 105 (-1)

Walla Walls 105 (+2)

Spokane 98 (+3)

Yakima 104 (+3)

If you go to the NWS Portland site you can see the latest in five minute increments and Portland is now up to 109. Dang they were at 100 at the same time yesterday, (+ 9) now. 

I also saw Seattle dropped a bit as the winds changed to from the West. Portland has not had that change.

[GaWx]

1PM PDT vs 24 hours ago:

Portland 110 (+6)(warmed 5 last hour)

SeaTac      99 (+3) (cooled 3 last hour)

Pendleton 109 (+3)(warmed 4 last hour

Walla Walls 106 (0)(warmed 1 last hour)

Spokane 99 (+1)(warmed 1 last hour)

Yakima 103 (+1)(cooled 1 last hour)

[nycwinter]

yesterday seattle was predicted by some to hit 112 not even close today..including the nws in seattle..

[Roger Smith]

I was not aware of any predictions of 112 for SEA unless they were humidex predictions (which verified near that level). I watch local SEA and GEG t.v. news and weather segments and the general range of predictions was accurate in all regions (same in BC). We knew this was coming a week ago and it has been on the news cycle in terms of get ready for about a week. All of these coastal urban areas have very large variations from one part of town to another, so the airport high is just part of a greater complexity. YVR is more marine-modified than most of the urban area it represents and a better idea of conditions for most of the two million residents of greater Vancouver can be gained from the Pitt Meadows station which is inland (Abbotsford even more so). For Seattle and Tacoma, SEA is also somewhat more exposed to sea breezes than large parts of those two cities but at the same time a few neighborhoods of Seattle are probably more exposed than SEA to sea breezes. Here again, in some heat waves you'll get a better representative temperature from McChord Air Force Base which is situated between the two cities and inland several miles. 

The bottom line is, it is dangerously hot in a coastal region that does not get a lot of severe heat waves even in peak season. Our climate is a bit different from the east coast, we don't just glide into summer through June, quite often there's a long delay of full summer heat and drought (which is normal there for about 6-8 weeks) until the second half of July. Even in the hotter interior regions, June is usually quite temperate and the main heat arrives in mid to late July and persists through most of August. That's the main story here, a full on midsummer heat wave in June is considered odd here, I wouldn't imagine it would seem that odd in NYC or DC (although mean temps are still rising in late June and so are daily records, the differential is larger out here at least by the coast). 

[TimB]

16 minutes ago, nycwinter said:

yesterday seattle was predicted by some to hit 112 not even close today..including the nws in seattle..

It’s not over yet. Yesterday they got to 104 and they’re 5 degrees ahead of where they were 24 hours ago. 

[GaWx]

2PM PDT vs 24 hours ago:

Portland 112 (+3)(warmed 2 last hour)

SeaTac      103 (+5) (warmed 4 last hour)

Pendleton 109 (+2)(no change last hour)

Walla Walls 107 (-2)(warmed 1 last hour)

Spokane 101 (0)(warmed 2 last hour)

Yakima 105 (+1)(warmed 2 last hour)

[MN Transplant]

The state records look like they might fall today.

Washington:  118 (1961).  Currently 116 or 117 on a downslope wind at The Dalles (KDLS).

Oregon:  117 (1939).  Currently 116 or 117 at Salem (KSLE).

[donsutherland1]

3 pm PDT:

Seattle: 105

Portland: 114

[bluewave]

 

 

[donsutherland1]

4 pm PDT:

Portland: 115

The Dalles, OR: 118

[MN Transplant]

1 minute ago, donsutherland1 said:

4 pm PDT:

Portland: 115

The Dalles, OR: 118

Interestingly, while The Dalles is in OR, it looks like the observation is taken across the Columbia River in Washington at the airport. So, that should be a tie for the WA state record.  Salem lost a few degrees after a change in wind direction.

[MN Transplant]

1 hour ago, MN Transplant said:

The state records look like they might fall today.

Washington:  118 (1961).  Currently 116 or 117 on a downslope wind at The Dalles (KDLS).

Oregon:  117 (1939).  Currently 116 or 117 at Salem (KSLE).

Some sites have 119 for Oregon in Pendleton in the late 1800s.  That might be the record and it may have to wait until tomorrow.

[sojitodd]

Environment Canada is reporting that Lytton BC hit 47.5 so far today. That would be a new all time Canada record,

[Roger Smith]

Looks like that all-time Canadian record lasted one day, it's edging up to 47 C at Lytton BC now. 

Probably the most remarkable temperature on the list is 40 C in downtown Victoria BC. YVR maintains a sea breeze and is stalled at 31 C, however, as I said that reflects almost nothing about what two million people in greater Vancouver have outside their homes, the range for 90% of the urban area is probably 36 to 41 C at present. A few lucky seafront areas are in the 20s. 

Another traditional hotspot, Osoyoos, is up to near 43C and Warfield near my location is 42.2 C. 

Have to say I am acclimatizing to this, if you take a very cold bath about twice a day and don't exert yourself, it feels comfortable enough inside, we don't have a thermostat because there's no heating system to control here but it feels like it's about 32 C (90F) inside. Somebody called to ask if I was okay being an old person, so I said sure thing, this is nothing compared to 1936 in North Dakota, had to take off the t-shirt for that one. 

[donsutherland1]

Another day, another Canadian national high temperature record!

From Environment Canada:

https://twitter.com/ECCCWeatherBC/status/1409655648220958722?s=20

Weather summary
for British Columbia
issued by Environment Canada
at 5:36 p.m. PDT Monday 28 June 2021.

Discussion.

The following data is preliminary and will be updated later tonight 

The following areas will have set a daily maximum temperature record 
on June 28, 2021: 

Lytton Area (Lytton RCS) 
Preliminary new record of 47.9 
Old record of 39.6 set in 2015 
Records in this area have been kept since 1921 

End/PSPC

Temperature Conversion: 47.9°C = 118°F

[donsutherland1]

51 minutes ago, MN Transplant said:

Interestingly, while The Dalles is in OR, it looks like the observation is taken across the Columbia River in Washington at the airport. So, that should be a tie for the WA state record.  Salem lost a few degrees after a change in wind direction.

Yes, it would at least tie the Washington record. Pasco might make a run at it tomorrow.

[MN Transplant]

Seattle tops out at 107.

[sojitodd]

Just now, MN Transplant said:

Seattle tops out at 107.

Yeah I just saw that. Funny as they have 108 recorded for 4:35 pm there. Must have been adjusted.

[MN Transplant]

6 minutes ago, sojitodd said:

Yeah I just saw that. Funny as they have 108 recorded for 4:35 pm there. Must have been adjusted.

The 5 minute obs are rounded and converted from F to C to F, which makes them problematic to take at face value.  They can be a degree off.

 

Actually, I made a thread about it a while ago:  

 

[raindancewx]

Salem, Oregon. Keep in mind, Phoenix also had ~14% humidity when it was also 117 on the 18th. 

[MN Transplant]

 

 

[donsutherland1]

Seattle finished with a high of 108.

https://twitter.com/NWSSeattle/status/1409688733247438850