Tough Sleeping This Summer? You’re Not Alone!

August 28, 2014

It’s been a common saying in the Willamette Valley (including Portland) that you don’t need air conditioning in our climate.  I’ve been hearing that since the 1970s when I was a kid.  After the past two summers, many would disagree now.

Last summer we set a record for most nights above 60 degrees here in Portland…44!

Well here we are on August 28th, and now we’ve seen 40 such warm nights this summer so far. BMAC 60 Degree Nights  I think it’s quite likely we’ll see 5 more between now and the end of September so we’ll probably set a new record for a 2nd year.


So what’s causing this?   One thing that isn’t…plenty of these nights have been under perfectly clear skies, so it’s not as if we’ve been seeing lots more cloud cover at night.  That would sure raise overnight lows.

More likely it’s a combination of the both the urban heat island effect and our warming summers.

I can’t speak with any knowledge on the first because I haven’t check outlying areas (like Aurora, Battle Ground, Sandy etc…) to see if they have seen a similar rise in overnight temps.  Common sense would tell you that overnight temps in summer in a rapidly growing metro area should warm; although PDX isn’t exactly surrounded by concrete and buildings.  You can see the increase in warm nights since 1941


As for the warming summers…our summers have definitely been warmer, check out the June-August temps for the lower elevations of western Oregon.  timeseries_summer_willamettevalley  That’s Oregon climate zone #2.  It’s also interesting that summers seemed to cool from around 1955 to 1980, then warm again following.  With warmer summers, one would expect both warmer daytime highs and warmer nights.

Will this continue?  History would say we will be in unprecedented territory if we had a THIRD summer of 35-45 warm nights.  Looking at that chart you can see we’ve never had more than one or two summers like this before cooling a bit again.  So it’s quite possible next summer is more reasonable.  But the big picture also shows that in a slowly warming climate there will be more of this in the future…

My advice is to get at least a one-room air conditioner if you live in an urban area.  They are more efficient than they have ever been and cheaper than they were 20 years ago!

Chief Meteorologist Mark Nelsen

Is It the Warmest Summer Ever in Portland?

August 26, 2014

11pm Tuesday…

The short answer is a “no“.  But it’s one of our warmest ever recorded here, and that’s without any real heatwaves!  Let me explain how that has come to be…First, here are the official numbers from this afternoon…


And the number of 90 degree days so far this season…

BMAC July 90 degree recap


Notice Salem has seen 9 more 90 degree days than Portland, yet nowhere near a record as you can see in this graphic from the NWS.


Not sure why it says Portland averages 12 since the 1981-2010 30 year NCDC average is 13.6 days.  I’ll have to check the numbers again.

So let’s talk about this summer…I did some number crunching, finishing off the August numbers with our 7 Day forecast. Assuming that forecast is within a few degrees (one hopes), here is how the summer should rank….


Generally meteorologists consider summer in the northern hemisphere as the 3 warmest months June-August.  Of course in some places (along parts of the west coast) September is the same or warmer than June.  But for most areas it’s June-August.  Anyway, it appears August will end up the 2nd warmest in Portland.  That’s where the official records are kept at PDX back to around 1940.  It’ll also end up the 4th warmest month (of any month) in our history.  That’s after July 1985, July 2009, and August 1967.

What about Summer 2014?  We know it is the warmest since 2009.  Remember those 9-10 days above 90 and two days at 106?  That was definitely “Africa Hot”!  This summer should end up 3rd warmest behind 2009 and 2004.  That’s a hot summer…

Several things I’ve noticed about this summer…


Much of the summer we’ve seen an upper-level ridge just to our west, out in the eastern Pacific.  It’s quite similar to the pattern we’ve seen off/on for about 18 months, most likely related to the huge pool of above average ocean temps in the eastern Paciifc Ocean.  With the ridge frequently in this position the past 2 months or so, we got weak onshore flow, but rarely get a hot thermal trough west of the Cascades.  In fact only once between mid June and late August did we get gusty easterly wind in the Gorge, that was during the 99 degree event the 1st of July.

Another effect of this pattern?  It’s been consistently warm, with no prolonged periods of cooler than average temps, yet no heat waves.  We did see 5 days at the end of July and early August with high temps between 89 and 92, but that barely qualifies as a heat wave here in Portland.  Yes, I know it was hotter to our south and east, but I’m specifically talking about the Portland metro area. 

Did you notice we didn’t hit 100 this year?  A little weird since it’ll be the 3rd warmest summer.  That’s related to the lack of strong offshore flow at any point during the summer.

And did you notice what was missing much of the summer?  Morning low clouds.  I noticed how many more days started sunny this July and August compared to the past few summers (I really liked that).  The marine layer was often present, but very thin in the metro area.  Just enough to keep us out of the “real hot” range and more in the “a little hot” range.  I don’t really know what that means, but hopefully it makes sense.

It’s pretty obvious looking at 7-10day maps/models that we’re headed into a cooler than average weather pattern as we start September.  For the next week or so we’re done with the continously warmer than average weather.  Take a look at the 12z ECMWF ensemble chart



So what are YOUR thoughts about this summer?  Discuss and (nicely) argue below please…

Chief Meteorologist Mark Nelsen

3pm Tuesday…Turning into a Scorcher Today

August 26, 2014

Wow, already up to 91 at PDX at 3pm. PLOT_Temps_Metro  I have a feeling we’ll end up around 94 degrees.  If you’re tired of hot weather, hang on, after tomorrow’s high in the upper 80s temperatures plummet and the 7-10 day period looks more like September.

Category 5 Hurricane in Eastern Pacific

August 24, 2014

The National Hurricane Center announced today that Major Hurricane Marie is the first Cat 5 storm in the eastern Pacific in 4 years.  Take a look at the water vapor imagery…


That’s a beautiful hurricane!  At 8pm winds are 150mph and it’s about 475 miles SSW of the southern tip of Baja California.  So this storm will pose no threat to land in the form of wind, storm surge, or rain.  It will track well out to the west south of the upper-level ridge that is along the western USA coastline.

But the tremendous waves & swell generated by this storm are forecast to arrive along the beaches of southern California in about 48 hours.  ww3-enp_epac_060_regional_wv_ht

The wave watch model above shows 9 meter waves, and the local NWS offices in California are warning of localized erosion, flooding, and some damage.  Of course I suppose the surfing will be great!

Up here in the Pacific Northwest it’s possible some of this moisture will enhance our showers next weekend.  Or it may stay to the south in northern California, or it may stay well offshore.  We’ll see.

The past few days there was another blowup in the comments.  It happens about every 6 months…yawn.  I didn’t even notice for the first two days because the weather is so slow, but then I see it got resurrected and brought into a new posting!  Geez, what is wrong with people!  I’ll be honest, I think at least 60% of the readers find it entertaining, at least that’s what I hear on the street and via emails.  In the past I’ve let it go a bit, or banned a few people for a couple months (last spring).  

But this time was a little different.  When the entire newsroom receives emails about it, then it becomes my problem, not just a few offended posters.   I’m not willing to damage my career or relations with my bosses over folks picking on other posters or someone going all “Mt. St. Psycho” with profanities and threats.   Or having drunk people on the blog posting about who knows what.  And really the only reason people went at it this time was because only this blog allows anyone to engage with others directly.  This was used as a battleground.  And Weather Daddy doesn’t like that!  As a result I’ve added 5 names to 2 others that are on “semi-permanent” moderation.  That means you can comment, but I have to hit the approve button.  Technically you are not banned from here, but I can’t trust you to not get out of control.  The sad part is that I actually enjoy every one of you and several of you bring really good info to this blog.  

So nothing personal, but it’s just too much chance that it’ll come back to haunt me at some point.  I’m cutting my losses ahead of time.

Remember that there are at least 2 good Facebook discussion groups here in the Portland area.

FOX12 Blog Discussions is run by Brian Schmit:

PDX Wx Analysis by Rob Grimes:

Chief Meteorologist Mark Nelsen

Baby Mac Arrives!

August 23, 2014

11:00pm Saturday…

We’re happy to announce that Brian MacMillan is a daddy! His wife Ashley gave birth to a healthy Avery Lynn MacMillan at 5:45pm this evening.  5lbs. 10oz.  & 19 inches.



Chief Meteorologist Mark Nelsen

By the way, the comments have been turned off for a week or so, or at least until I go through them to see who deserves a permanent dumping this time around.  Please don’t email me and tell me how innocent you are; no need to create even more drama.

Decreasing Daylight & A Warm Weekend

August 22, 2014

I just noticed that we’ve lost 2 hours of daylight since the longest day of the year in late June.  That’s a one hour later sunrise and one hour earlier sunset.  We’re at the time of year now where the daylight loss will accelerate. MarkDaylightDecreasing1  But the warm summer weather will continue!  We may get close to or hit 90 degrees again the middle of next week, so enjoy the milder weather over the weekend.  Skies look mainly (or all) clear west fo the Cascades away from the coastline.

Chief Meteorologist Mark Nelsen

A Taste of Fall This Morning

August 21, 2014

10pm Thursday…

Quite a chill in the air this morning, lots of 40s around the metro area.  PLOT_Lows_Metro For some of us it was the coldest in about 2 months.  At PDX the low of 54 was the coolest since July 25th when we also hit 54 degrees.  MarkTemp_Last12Days_LowsPDX That broke the long string of mainly 60+ nights we’ve been seeing since late July too.  Between that and what I see on the maps ahead, it’s pretty obvious we’ve passed the “peak of summer”.  Sure, there will be plenty of warm days (80-90 degrees) in the next month, but the long strings of hot weather are history for this year.  It probably doesn’t help that some kids go back to school in just 4 days, the rest in less than 2 weeks.

I didn’t post over the past week because the weather was slow the end of last week and over the weekend, plus my family and I did our last camping of summer at Diamond Lake (near Crater Lake).  No more vacation time in the next month, in fact I’m probably going to earn a bunch of days since Brian is about to go on paternity leave and we’re short a weather person.  But that’s how the business goes, you work long hours and many consecutive days at times.

Here are a couple of pics from the area.  I’m no photographer, and it was real hazy.  My son and I hiked up Mt. Bailey above the lake…a tough climb but not technical by any means.  The last picture was a little “window” through the ridge of rock at the top of the mountain.  That was real interesting; hate to fall out that one!




Chief Meteorologist Mark Nelsen