A Warm & Dry June Turns Into A Cooler July Start

8pm Sunday…

Back at work this evening!  After checking out the weather maps/models I can see I’ll be dealing with “why is it so cool?” whining this week.  More on that in a bit.

Apparently I missed a tornado?  Yep, that EF-0 in NE Portland on the 1st

Mid-summer and mid-winter are the tornado “off-season” in Western OR and SW WA.  The 1950-2019 records from SPC show this is the first July tornado on record in our area.  WAY back in the past a few were recorded in July (early 1900s), but that’s before detailed records were kept beginning in 1950.

The first official summer month (June) ended warmer and drier than average.  After an early June heat wave the weather has been pretty normal for early summer.  We haven’t seen a cool June in 8 years!

July has been a different story the past 11 years.  Only 4 have been unusually warm, the rest either cool or just a little warmer than average.

July Month In Review

So what’s ahead?

  1. There is NO sign of hot weather the next 7-14 days.  At least the first half of July will not feature any heat waves and 85+ is very unlikely through the 15th.
  2. Expect more cloud cover than normal to continue through the next week.  I don’t see many days that start sunny.
  3. Later Tuesday through early Thursday will be wet at times and even unusually humid as a subtropical airmass moves overhead.  Overnight lows will warm to above average with the cloud cover and humidity.
  4. Still, temperatures will remain near or only slightly below normal
  5. After some blazing hot summer weather the past few years, we ARE overdue for this kind of weather.

To summarize

  • Portland isn’t sunny Southern California, hot Atlanta, or sunny/dry/hot Denver (in summer).  We live in a temperate marine-influenced climate; notice the greenery all around us?  This is perfectly normal unless it continues for the next 6 weeks.  It doesn’t necessarily mean the entire summer will be cloudy and “cool”.  No need to panic for now if your livelihood depends on renting standup paddleboards.

 

Maps and models are in good agreement that an upper-level trough pushes up against the Pacific Northwest coastline later Tuesday.  This one has plenty of subtropical moisture.  Sea surface temps offshore are well above average too.  The anomaly map shows a warm “blob” in the Eastern Pacific

SST_Anomaly

WRF-GFS shows the IVT (Integrated Vapor Transport) quite juicy, but most of it is directed north of Oregon Tuesday evening through Wednesday.

ivt.60.0000 Because of that, this doesn’t appear to be a big soaking, well under 1/2″ in western valleys of Oregon and SW Washington.  More likely .10-.25″.  Enough to wet the dust and once again delay fire season.  There are no large fires burning in Oregon or Washington. Excellent news.

Looking farther ahead the ECMWF ensembles show the cool upper-level trough this Wednesday centered offshore

m500za_f072_bg_NA

Then this coming weekend.  Trough is there, but a bit weaker.  Temps warm to around average.

m500za_f156_bg_NA

Then 10 days ahead (Wednesday the 17th) a very unusual July pattern on both the GFS and ECMWF ensembles.  A large upper level negative anomaly covering the Gulf of Alaska.  Very interesting, but 10 days out.

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Chief Meteorologist Mark Nelsen

28 Responses to A Warm & Dry June Turns Into A Cooler July Start

  1. Jason Hougak says:

    Love it, love it, love it

  2. Roland Derksen says:

    Can’t complain over here either: So far , my total amount for the month is 0.68 inches. That’s more than the last 2 Julys combined, but projected over 31 days it’s quite close to the long term average.

  3. boydo3 says:

    Is the “blob” really back!? That’s a bad deal for the chinook salmon that migrate north for their breakfast, lunch and dinner.

    • Kyle says:

      It never really went away! As long as whatever is heating it keeps happening it will to some degree always be there. It just got dampened for a while.

  4. Jake in Gresham says:

    This weather is sheer perfection. I’ve gone hiking almost every other day. And went blueberry picking today. If Summer stays like this you won’t hear a peep from here.

  5. Jason Hougak says:

    What a great July, Oregon needs this.

  6. Roland Derksen says:

    A dark, showery morning here- we had 0.44 inches overnight, which isn’t a lot, but after yesterday’s 79F maximum under mainly sunny skies it feels like quite a difference. Here’s an interesting stat; I’ve recorded 2 Julys in the past (1982 and 1986) that were cooler in mean temperatures(and wetter) than the June month before them.
    Anyone else have something like that to tell ? (just wondering)

    • Pat says:

      Yes. I remember July 1986 here in Northwest Oregon as being a bit cooler than average.

    • Roland Derksen says:

      Here’s another discovery about July I’ve made; It’s not always the driest month of the year. Out of the past 44 years (1975-2018)
      it’s been the driest 36% of the time. And 23% (10 years ) it’s been 4th driest or lower for me.

  7. andy says:

    Raining moderately at times here in Albany. What a change this year. Feel bad for the farmers though, some were still working with straw and hey. it will be interesting what August will be. Checked the update on MT Hood, looks like over 30 tremors now. The volcanic observatory doesn’t seem to concerned though.

  8. Analogs would suggest August to outperform on heat this year. Just my take. Bottom of solar cycle plus ebbing of El Nino could provide for active winter. Blob heat throws in an interesting variable. It’s interesting we’re getting a classic winter like storm in mid July.

    • Andy says:

      I was thinking the same on August…hot and dry, however, I don’t think we expected a December storm in July. The satellite loop looks like a winter season storm.

  9. Roland Derksen says:

    I am also expecting the :whiners” to show up soon, if the weather doesn’t change much in the coming week. As Mark says, we were overdue for this kind of weather. Remember July 2011 ? That was only a few years ago.

    • JERAT416 says:

      Wasn’t 2008 the year July started cooler than this year and many said summer was over, before August hit and it got nice and toasty?

      • Roland Derksen says:

        Intresting- I think summer 2008 was a bit different in my end of the Pacific NW, but I’ll have to check. I do recall it was warm and sunny through most of August, but toward the end it got cooler and rather showery.

  10. Portlandsummerfail says:

    Nothing worse than a cloudy summer that leads into a cloudy fall, then winter and so on. This Portland summer is the worst it’s been in a while. Here’s hoping that next summer is actually sunny.

  11. Sounds like my idea of perfect weather ahead.

  12. W7ENK says:

    Glad I’ve been able to experience peak Summer in Estonia. Sunny days, an onshore breeze coming in off the Baltic, only a couple rainy days, and only one crack of thunder under a heavy downpour, but overall the weather has been fantastic. Highs in the upper 60s to low 70s, lows around 50 to 55, and twilight all night long.

    Looks like we’ll be coming home to some cool and wet weather late next week.

  13. PAUL D says:

    No heat waves for the first half of July? Now that’s some AWESOME news!

  14. Lisa Nowak says:

    June might have been warmer and drier than average, but 19 out of 30 days started out cloudy (or were entirely cloudy or rainy). Same deal with May. Now July is starting out the same way. That seems like a lot more gloomy mornings than average. I’m hoping this year will be like 2016 when we had a lot of cool, gray weather the end of June and beginning of July, but we got a reset around the 20th and had a hot summer after that.

  15. JohnD says:

    Thank you Mark for your detailed and interesting analysis–as always. We all have gotten used to stretches of deep summer weather in many of the recent years–even amid our marine climate.
    We are definitely in the summer weather window now. Time will tell if this one ends up being a relative anomaly. Interesting what you show in the potential longer term too.

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