98 Degrees Monday…Smoky But Cooler Today

August 29, 2017

10am Tuesday

Monday was ridiculously hot; we hit 98 in Portland which is also the 11th day at/above 90 this month.

It’s been 30+ years since we’ve seen so many 90 degree days in August…11 so far.

As of now August is also the warmest we’ve experienced here in Portland…beating the record just set in August 2014 (only 3 years ago!).  That year the nights were a bit warmer but daytime highs weren’t quite as extreme.

Air quality has been going downhill in the Willamette Valley since yesterday evening as more and more fire smoke moves up from the south.  Check out the smoke on GOES-16 visible imagery just before sunset last night.

The real thick stuff is now over us, but it’s only right over the valley and east.  Note the lack of smoke over the Coast Range on the morning loop:

The thickest smoke should gradually get pushed east late in the day.  Tonight a strong marine push should clear out all of the smoke west of the Cascades.  Wednesday we should see blue sky again…after the morning clouds.


  • Today will be very warm, but likely below 90 degrees
  • Lots of clouds the next two mornings and maybe even a spot of drizzle but with afternoon sunshine
  • Much cooler…highs mainly in upper 70s Wednesday/Thursday
  • Fire smoke goes away (for a few days) tonight
  • Another heat wave hits us for Labor Day weekend and will continue through the middle of next week
  • No sign of a soaking rain, or any rain

Of course we’ll cool down dramatically with the marine push Wednesday and Thursday too.  The bad news is we have Heat Wave #4 for this summer coming up Friday through sometime early next week.  All models are in agreement building a hot upper-level ridge right over us once again.  As early as Friday we’ve got 500 millibar heights up around 590+ over us…the heat will return quickly!  The ridge is firmly established again Saturday afternoon on this chart from the overnight ECMWF model.

It appears it’s going to stick around for 5-7 days too.  This is the FOLLOWING THURSDAY…5-6 days later

Hot in the west, unusually chilly in the eastern USA.  An early fall for them.

This hot ridge with 850 millibar temperatures up around +25 or so means that once again we will flirt with the triple digits, like Monday.  Hard to believe we’ll be moving through the first week of September at that time!

Take a look at the ECMWF ensemble chart for the next two weeks showing good agreement between ensemble members through the first week of September.  But even after that temps remain above average.  The first half of September is going to be more like a typical early August.  No sign of fall on the weather maps yet and no sign of any sort of decent rainfall:

The accompanying temperature forecast from the ECMWF is somewhat depressing if you’re sick of hot weather, showing 5-6 days of 90+ weather once again starting Friday:

One benefit of the hot August has been fantastic growth in our gardens…assuming you are watering them well.  Yesterday I had to pick my two-story high beans with the extension ladder…they were a little too far from the window to get the job done from upstairs.  But they sure look neat!  There are some morning glory vines wrapped up there as well.

Chief Meteorologist Mark Nelsen