Heat Wave #2 Rest Of This Week

July 22, 2018

9pm Sunday

Back from a nice vacation this evening and heat is back as well.  We hit 94 in Portland today, which means we have just about had our “typical allotment” of 90 degree days.  We average 13 days per year at/above 90 in our area…but we’ve definitely exceeded our average 4 out of the past 5 years

90 Degree Days Summer Heat

We are up to #12 already this year with another 7 likely on the way.  You aren’t crazy, we HAVE seen a string of hot summers starting in 2014.  Of course 2016 was only a bit above average but it has been ridiculously hot otherwise.

We had a nice cool down Wednesday through Saturday after that 7 day spell of hot weather:

High Temp Last 13 Days

As of this evening, it’s our 4th hottest July on record in Portland, 10th hottest in Salem.

Why such hot weather?  As mentioned in previous posts this month, upper-level heights have been running quite high compared to normal.  A strong upper-level ridge is centered right over New Mexico right now, which isn’t all that unusual for July.

Jet Stream Forecast 2017

This chart shows the big ridge, centered far to our SE (the lines, not colors).  But most important for us are the warm colors showing that even well away from the big ridge heights are far higher than normal in the Pacific Northwest and British Columbia

m500za_f024_bg_NA

It stays there most of the week but then edges closer to us, centered over Nevada/Utah next weekend.

Jet Stream Forecast 2017_2

That’s why I’ve put in temperatures near 100 again for next weekend.  We’ll see how that plays out.  Most important, the ridge stays nearby and keeps us continuously hot all this work week without any sort of good marine push to bring us cooler ocean air.

Models have been in great agreement showing this pattern.  Check out the ECMWF ensemble 15 day forecast surface temps at Portland:

KPDX_2018072212_eps_min_max_15 (1)

That’s a long hot spell, but you also see some sort of pattern change arriving about the middle of next week (we hope!).  Just as August arrives the ridge seems to want to weaken…maybe.

By the way, my family and I just spent two days at Waldo Lake…hadn’t been down there in almost 10 years.  That’s the 2nd largest lake in Oregon and typically real chilly, but perfectly clear.

photo_waldolake

We got lucky; the heatwave has warmed up the surface to at least 65-70 degrees, maybe even a bit warmer along the edges.  What a beautiful place with no motors and so peaceful as well.  Mosquitoes weren’t horrific, but definitely around.  As always August is better at Cascade lakes mosquito-wise.  Then we spent two nights at Clear Lake…getting pretty low early again this year.

photo_clearlake

 

Won’t be much left in a few weeks up there, I was almost able to walk across the wide section.  So many beautiful places to visit but just not enough time!…maybe in retirement.

Chief Meteorologist Mark Nelsen