Portland’s Driest April In 50+ Years

11pm Tuesday…

Today was another very nice spring day.  Temperatures rose into the lower 70s west of the Cascades (except along the coastline).  This is what we typically see around Memorial Day, still a month away.

web_ORWA_HIGHS_Today_West

Every day except the first four has been at/above average as well.

Do you realize this is the driest month in Portland since last July?  That’s very dry for April.  It looks like we’ll see less than .20″ rain coming up with a weak system Wednesday evening and early Thursday.  That means we end up with less than 1.00″ for the month.  We haven’t seen that since 1966.

MarkDrySpells April

And what a change from the past few years…I remember the closed sports fields (standing water) in 2017 & 2018.

MarkDrySpells April2

The warm and dry April has taken quite a toll on the mountain snowpack, it’s melting much quicker than what we’d typically see.

Compare the April 1st “snow water equivalent” to the 28th.  Below 50% of average now in parts of southern Oregon and close to that 50% number in central Oregon.  These numbers will continue to drop the next 10 days since we see more warm weather next week

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What’s ahead?  I see more of the same…drier and warmer than normal the next 7-10 days.  But that DOESN’T mean totally dry weather.

A strong upper-level ridge across the western USA is keeping weather systems very weak as they move by the Pacific Northwest.  This is tomorrow.

ecmwed

That ridge weakens quite a bit and a cool airmass attempts to move inland this weekend…this is Sunday.  Notice below normal heights across the entire northeastern Pacific, but it’s not directly over us.  Showery, but not crazy wet or cold.

ecm_sun3rd

But by the middle of next week the warm upper-level ridging returns, this time perhaps directly overhead

ecm_wed_6th

These maps are all from the European model ensembles, but other models are similar.  This COULD lead to our first 80 degree weather next week.  For sure we see another spell of mainly dry weather after this upcoming weekend.  This is 24 hour rainfall for each of the GFS ensemble members (one horizontal line per member) centered over the northern Willamette Valley.  You see the weekend showers, then very few members are forecasting significant rain next week.  Many are totally dry.

gfs-ensemble-all-KMMV-indiv_qpf_24-8075200

So, it’s been a nice spring but we could sure use a major week-long soaking sometime in May!  For now I don’t see any sign of that happening.

Chief Meteorologist Mark Nelsen

21 Responses to Portland’s Driest April In 50+ Years

  1. paulbeugene says:

    T storms looking possible in day 7-10 period, perhaps nocturnal t storms Monday night next week. A little ways out but keep eye out for those donkeys

  2. Jason Hougak says:

    Frost this morning in the foothills

  3. lurkingsince’14 says:

    Hey Josh – it’s legit raining! Pop some bubbly and drop the confetti! 😆 😉

    Ha but really with 80s on the 7 day a damp weekend is probably a good thing

    • Joshua Lake Oswego says:

      Ha. I’m sticking with my predictions. Yea, it’s going to be warm with really low humidity in less than a week. .25” or so isn’t going to help in the slightest.

  4. BullMtn97 says:

    Eugene: .67 in
    Salem: .71in
    Portland: .59 in
    Olympia: .51 in
    Seattle: .48 in

    • Joshua Lake Oswego says:

      I don’t know where you’re getting your info.This WEEKEND per NWS:

      Eugene: .31’’
      Salem: .53’’
      Portland: .44’’
      Olympia: .72’’
      Seattle: .30’’

      Overall, I nailed Eugene and Olympia. Portland and Salem exceeded my predictions. Nice! Seattle underachieved.

      It was nice while it lasted. Here comes summer weather.

  5. runrain says:

    SPC has included Portland in it Marginal Risk category for severe weather tomorrow. We’re on the very western edge of that risk but nice to be included in something that is more common to the midwest. Hope it pans out!

  6. Joshua Lake Oswego says:

    Ok, who wants to play a game? Guess how much rain Eugene, Salem, Portland, Olympia, and Seattle will get over the weekend. The latest operational runs of the ECMWF, GFS, and GEM show a minimum of .50” for all cities and up to 1” depending on the model and location. Let’s call the average .75”.

    So, knowing that the models are about 62-67% too high for the Willamette Valley, and that Olympia and Seattle out-perform us 100% of the time regardless of forecasted amounts, below are my predictions through Sunday at 11:59pm:

    Eugene: .32”
    Salem: .28”
    Portland: .24”
    Olympia: .81”
    Seattle: .72

    • Paul D says:

      Hillsboro 0.10″. just call us the Dust Bowl NW.

    • BullMtn97 says:

      Eugene: .61in
      Salem: .71in
      Portland: .59in
      Olympia: .55in
      Seattle: .48in

    • Doug in LO says:

      .24” for us is probably optimistic. We get the usual pity dribble and not much more.

    • Doug in LO says:

      Just checked the radar. The big green mass north of us. Again. We’re left with tail end scraps. Again.

    • Peter Christenson says:

      0.51 so far in this event with a lively shower coming in. And a bit of thunder. Sad how weather-starved we’ve been. All in all, though, I’d have to describe this as performance. Maybe even overperformance.

  7. boydo3 says:

    4.45″ for April on the south coast. Dry but not dusty..

  8. Paul D says:

    Welcome to the NW Desert.

  9. Timenator says:

    First!

  10. Debra brown says:

    Thanks Mark. Sure miss our seasons. Boring weather sucks

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