Memorial Day Weekend Forecast: Hot Weather Ahead Too

9pm Thursday…

We’ve been in a “cool” weather pattern for the past two weeks now.  By “cool” I mean the extremely warm weather that dominated April and the 1st half of May has taken a break.  It’s been replaced by the typical ups and downs we see in May.  I think we have 3 more cool days and then meteorological summer arrives right on schedule, either May 31st or June 1st (or both) we may hit 90 degrees for the first time this season.  We have hit 89 twice and 88 once, but still no 90 at PDX.

In the meantime, we have a little thing called Memorial Day Weekend to observe.  It appears to be similar to last year, maybe a bit warmer.  I expect a few scattered light showers tomorrow and possible again Saturday, otherwise the weekend should be dry south of the Columbia River.  A little better chance of showers remains up in Washington through Saturday.  The Cascades look very chilly tomorrow and Saturday (what else do you expect in May???), then a bit warmer Monday and beyond.  Here are 3 forecasts for the mountains, coast, & central Oregon…click on each for a larger view





Over the past few days models have come around to a very warm/hot pattern in the long range.  Individual model runs have been all over the place with details like which days will be hot and which are more reasonable.  Due to this I am finding ensemble forecasting more and more useful.  That’s when any one model is run with many different “perturbed” variations.  Here is one example, the ECMWF meteogram from the 12z run has a real heatwave over us next week with 4 days around/above 90 degrees.


That’s because it digs an upper-level trough offshore and keeps a hot ridge over us.  I doubted that was correct and sure enough the ECMWF ensemble chart shows that operational run is an “outlier”.


That’s the blue line which is WAY above the red; the average of all the ensembles.  Thus I did not warm temperatures up way into the 90s, but kept temps around 90 for now.  The ensemble average output numbers are far more reasonable:


The GEFS ensembles (GFS ensemble runs) are similar showing a peak temperature Tuesday or Wednesday, then a secondary peak around Sunday the 5th:


Regardless, there is excellent agreement that after 2+ weeks of the cooler weather we are headed back into a much warmer than normal pattern.  After 3 more days of cool-ish weather we’re headed into some unusually warm weather.  This time it’ll be June and it won’t be so strange, not like that 85 degree stuff almost two months ago!

By the way, May will end up a bit drier than normal and there is no big soaking on the way through at least the 5th of June.  Here’s the GFS precip forecast for each run the last 3.5 days:


Chief Meteorologist Mark Nelsen



24 Responses to Memorial Day Weekend Forecast: Hot Weather Ahead Too

  1. Tyler Mode in Battle Ground says:

    Nice cool morning out here in Battle Ground. 40.7 degrees.

  2. Well, yesterday’s soaker did us a lot of good(1.73 inches): the air feels fresh, the sky is blue again and the plants are enjoying a good drink!

  3. WEATHERDAN says:

    Imagine that, a warming trend starting around May 28th with maybe the last couple of days in May over 80. Seems to me when I mentioned this about 10 days ago I caught hell from some local trolls. How could I predict this. Well maybe because several other sources showed why it would happen. Haven’t heard much from them (the trolls that is) of late. I wonder why. Enjoy the sunshine. Peace.

    • High Desert Mat says:

      Are you twelve?

    • My alter ego says:

      Don’t like being called out Matt? You were one of those that said on this blog that I couldn’t predict correctly 10 days out. You an Jason and a couple of others. Now that I did I just wanted to remind you. If you don’t like that tough marocas. Peace.

  4. Today’s the day we get our big rainfall for the month: I’m expecting at least an inch, maybe more. That’s great- we needed it, and looking at next week’s forecast we’ll be especially glad we got it.

    • Tyler Mode in Battle Ground says:

      Funny, the sun is shining here 🙂

      Had a great day up at Mt. Rainier yesterday. Snow and sun at the same time.

    • Tyler, that’s a great picture but it’s not what I’ve been seeing for the last several hours. Steady, at times heavy rain has tapered off into showers. I see some brightening to the southern horizon now, but we won’t get a good glimpse of the sun until tomorrow!

  5. Marc (Brush Prairie, WA) says:

    Can you imagine how hot it it’s going to get in S.E. Portland?

  6. . says:

    …..And right on cue. Back to way too hot weather AGAIN. Another horrible summer awaits.

  7. Jason Hougak says:

    All this cool weather has helped the mountain snowpack
    Snowing at Timberline
    28F with 3″ of new pushing the season total to 551″
    Keep those rivers flowin’
    I drew Rogue River permits to float the wild and scenic stretch just after 4th of July.

  8. W7ENK says:

    Re: Memorial Day Weekend

    “It appears to be similar to last year, maybe a bit warmer.”

    So, why are you calling for low to mid 50s in the Cascades then? We had virtually no clouds and highs up there into the 70s all weekend last year, pushing 80 by Monday. Short memory? Maybe you guys were stuck under a marine layer down in the valley…

    Headed to the same place again, I’ll let you know how it went when we get back.

    • Mark Nelsen says:

      It was in the upper 40s to lower 50s at Government Camp all 3 days last year. I just checked the climate data. Maybe you are thinking of the week after?

  9. Dizzyland says:

    Does anybody know why The Weather decided to go private without telling anybody? Did IFred (The Admin) finally snapped and lost it with the rest following en suite?

    The forums were dying anyways and I wonder if this is the final nail in the coffin?

  10. Finally! I’m seeing some pretty good showers here this evening- actually got soaked in one coming home before 9pm. We’ll need a lot more, however.

  11. Steven James says:


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