May Arrives With More Dry Weather

A new month is here, but the weather pattern hasn’t changed much.

We ended up with .39″ rain at PDX, making it the driest April on record.

At the last minute (the last few hours of Friday) a surge of rain fell throughout the Willamette Valley. That pushed Salem’s total down to only #20 driest. Still near the upper end, but no record. Olympia ended up 3rd driest, Astoria was 2nd driest, North Bend was #4.

Of course spring continues to be the driest on record in Portland. Same in Astoria, Eugene, and Pendleton. It’s the 2nd driest spring on record at Olympia. But only #13 at Salem. IF PDX gets less than 2.20″ or so this month, it’ll still be the driest spring on record there. But it CAN rain a lot in May. One can argue we are overdue. We haven’t seen a “wet” May since 2013! Hopefully this May (or June) we’ll get a good soaking at some point

May in our area sees a gradual transition from the cool spring weather to (usually brief) periods of summer conditions. In many years we see at least a few days in the 80s, or even some brief 90s, before a return to more seasonal temps in the 60s/70s.

What do I see through this first 10 days of May? First we have a very weak/dying front moving overhead tomorrow afternoon. Little or no rain with this one. Then a strong ridge of high pressure pops up briefly Wednesday. A combination of strong offshore flow & thermal trough (in blue) west of the Cascades should give us one day of 80 degree weather Wednesday. Check out the offshore flow for 5pm Wednesday.

We might even get temps 75-80 Wednesday midday/PM on the northern Oregon coastline. Due to 850mb temps forecast between +15 and +17C over Salem, it’s possible we hit 85 and our warmest day of the year.

Then it’s back to onshore flow near sea level for Thursday. At the same time a cool upper-level trough is approaching. This is right overhead Friday/Saturday for lots of showers. Maybe some thunder? We will see. Colors here represent upper-level height anomaly. Red = higher than normal heights

Unfortunately, this doesn’t appear to be a big pattern change. By Sunday the 9th the cold trough is leaving the area and higher than normal heights fill the Gulf of Alaska. This keeps significant wet systems away from us

It’s still there on Thursday the 13th.

This leads me to believe we won’t see a significant wet spell in the first 10+ days of May. Keep watering! If we get lucky, maybe 0.50″ out of the showers Friday/Saturday

By the way, we recorded a fun FOX12 WEATHER podcast last week. We caught up with Stephanie Kralevich! She was a member of the weather team here for about 9 years from 2005-2014. Some great old stories…find it in Apple Podcasts or you can listen directly here: https://www.kptv.com/podcasts/weather/

Chief Meteorologist Mark Nelsen

39 Responses to May Arrives With More Dry Weather

  1. Roland Derksen says:

    High overcast skies here currently, with some light rain expected tomorrow. I’ve also noticed the light amounts of precipitation over the past few weeks. Other than April 30th, and March 24th, I haven’t measured anything in a day over half an inch since March 21st.

  2. W7ENK says:

    Looks like the high cirrus shield ahead of our next system has moved overhead a bit earlier than expected. My temperature seems to have capped at 78, as I’ve now lost all semblance of direct sunlight (shadows). Methinks today’s forecast for 85 will be unattainable.

    • W7ENK says:

      Also partly due to the fact that those “gusty East winds” never materialized.

      • Lurkyloo says:

        It’s been fairly windy here for a while by Rose City Park. Maybe it just hasn’t reached you yet, Erik.

        • W7ENK says:

          It’s been relatively calm here all day, just some very light and variable breezes. Only started to pick up about an hour ago, light winds mostly out of the NW, though some stations to my South showing from the SW. Really nothing over 10 mph this side of the Columbia and West of I-205.

        • W7ENK says:

          lol

          Even Cascade Locks is reporting 9G13 right now. Stevensen right across the river is at 1G4.

          I’d say the East wind was a major bust. Not to worry though, I’m sure there will be plenty to come this Summer…

        • Mr T says:

          YEEEEEEEEEEEEEEHAAAAAAAAAAAAAWWWWW! Sorry got carried away. Glad the 80F is a ‘bust’. Finally a positive bust!

        • Mr T says:

          BTW: That was the rebel call I did against the heat only wish casters on here. 🙂 You know who you are.

      • Zach says:

        Yeah we are socked in with clouds out in Gresham and hovering around 75. 80+ isn’t happening.

  3. Joshua Lake Oswego says:

    The 12z GFS brings back the death ridge for late next week that I mentioned before. Wanna know how I know it will happen? I have family coming in from out of town, and without fail, that means that the weather will be the worst-case scenario or worse. To me, hot and arid is a worst-case, so, alas, get ready for 90 degrees. The arid part is already a given.

    • Joshua lake Oswego says:

      The Euro and GEM are both very warm beginning next Tuesday, The GEM remains warm through the end of the run. The Euro pushes the ridge east of us by the 14th as a low approaches from the NW. A strong low at that. Right over us on day 10. The GFS doubles down on the heat with triple digits possible around the 20th.

      Expect to see forecasted temps on your weather app going way up for at least the Tuesday – Thursday timeframe.

      My opinion is that a solution closer to the GFS and GEM will play out. High pressure ALWAYS outperforms expectation in regards to duration and intensity. If tur, get ready for our first heat wave of the year. Just what we need.

      • Zach says:

        There probably will be some sort of heatwave, but triple digits is very unlikely. I mean the 20th is 15 days out and what the GFS operational says past like day 10 is really just noise that I don’t even bother looking at.

        • Joshua Lake Oswego says:

          Oh, I know it’s not to be taken literally. The writing is on the wall for a heat wave though.

        • Zach says:

          Yeah. Doesn’t look like any sort of pattern change will happen through at least mid May. Hoping we se some sort of change to consistently wetter weather going into June.

  4. tim says:

    After this weekend the faucet gets turned off for foreseeable future which will allow my waterlogged lawn to dry out finally.

    • W7ENK says:

      With less than 4 inches of rain in Seattle over the current three-month period (MAM), I’m just going to straight up call you a liar, outright.

      Stop lying, Tim.

      • tim says:

        Since January 1st to may 3rd Seattle is 1.65 above normal so get your facts straight before you start calling someone a liar.

      • tim says:

        Yes you are correct, I was focused on the year to date but I suspect I’ll still be called a liar.

        • W7ENK says:

          Well, had you stayed inside the rails…

          With roughly 50% of average precip in the most recent 3 month timeframe (MAM) — that I’ve been talking about since my first comment here — I find your claim of a “waterlogged lawn” highly suspect. Unless, of course, your lawn is generally part of a swamp to begin with, in which case, why even bother?

  5. Garron Slocum says:

    The only time I pray for rain around these parts, is when I’m planning to do outdoorsy stuff in the summertime. Camping bonfires fireworks using four wheelers etc other than that I would rather be warm and dry as long as I can enjoy it!

  6. Garron Slocum says:

    Thanks again for all your hard work on here Mr Mark Nelsen! I’d love to see a warm to Hot Summer, I just hope we get a little bit more spring and summer rain so I can have a bonfire at the campsite this year! Couldn’t even go camping last year do the pandemic, then the fires. Hoping for a good year for tomatoes but a bad year for Forest fires and the pandemic.

  7. Paul D says:

    Measurable rain yesterday! Shock and amazement! Wasn’t much, but it was something.

  8. Joshua Lake Oswego says:

    Call me crazy, but to me, later this week is looking like another bust. .25’’ at PDX if we’re lucky from Thursday through Saturday. I will go with .18’’. Whatever has fallen by Friday afternoon is pretty much it. For at least another week.

    • Joshua Lake Oswego says:

      I hadn’t even seen the 00z Euro when I posted this. It’s game over. Yet another flop.

      • Zach says:

        eh, lets wait and see what today’s runs say.

        • Joshua Lake Oswego says:

          Let’s just say that my .18” estimate is very generous. More like .05”. The Puget Sound convergence zone will get all the fun.

  9. tim says:

    .26 so far here in seattle and with another 1 to 2″ forecasted this weekend that well put us above normal rain for May once again just like last year I thought la Nina is over?, we just keep getting slammed here in WA it’s been to wet.

  10. Grizzly Bear says:

    This all is so peculiar….4 and 5 months ago most everyone on this blog were praying and hoping for snow….fast forward to May and everyone is praying and hoping for rain….ha ha. And if it was raining you all would be hoping and praying for hot weather and sunshine…never satisfied with the reality of weather and climate.

    • Garron Slocum says:

      The only time I pray for rain around these parts, is when I’m planning to do outdoorsy stuff in the summertime. Camping bonfires fireworks using four wheelers etc other than that I would rather be warm and dry as long as I can enjoy it!

  11. 5OClockCharlie says:

    Looking like my “misplaced optimism” last week on getting rain is not so misplaced after all? Will I be vindicated or is this thing going to fizzle out by Thursday again? Interesting times for sure…

  12. Paul D says:

    Portland the new dustbowl

    • Mr T says:

      Oregahoma!

      • Lurkyloo says:

        Noooo! Have any of you read “The Worst Hard Time?” We can’t get there — not by a long-shot. But it does feel somewhat ominous. I wonder how we’ll look by September …

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