The Heat Is On: April-Style

80 degree temperatures are on the way, including to the Oregon Coast!  Hard to believe after seeing snow down below 3,000′ this weekend, but it’s coming.  Models have been telling us this for almost a week; so quite a good forecast.

The Highlights This Week

  • Warmest weather so far this year
  • 80s at the Coast Wednesday, maybe for some spots Thursday too
  • 80s in the western valleys of Oregon and SW Washington Wednesday and Thursday
  • Gusty east wind tomorrow through Thursday morning in and near the Gorge.  Gusts could exceed 50 mph tomorrow night and Wednesday.


Take a look at the 500mb (~18,000′) chart for Thursday morning; that’s quite a ridge of high pressure centered right on the West Coast!  We haven’t seen that this spring so far.  That blocks all storminess and when it’s in this position we get surface high pressure to our east.  Thus the breezy east wind expected the next few days.  And when the ridge is very “sharp-looking” like this one, we tend to get a nice sharp trough of low pressure down at sea level along or off the coastline.  That’s why in this case the east wind will make it all the way to the beaches.


How warm (hot) is it going to get?  Models are in excellent agreement that 850mb temps (~4,000′) will be around +16 to +17 over Salem/Portland Wednesday and Thursday.  When you combine that with maximum mixing of that air down to the surface due to the easterly wind, you get a high temperature of 85-90 degrees.  It is EXTREMELY rare to get 850mb temps above +16 in April.  In fact from 1992-2009, that’s 500+ days, there have only been 3 days that warm.  One that hit +17, and two that hit +18.  They were 86, 86, and 90 degree days here in Portland.  So will we break a record?


The red columns are the records at PDX for the next 3 days, with my forecast numbers in yellow.  Wednesday is the day in 1998 when we hit 90 on the last day of the month, so no record coming that day.  I have a feeling we may break a record on Thursday though.

Enjoy the sunshine!

Chief Meteorologist Mark Nelsen

31 Responses to The Heat Is On: April-Style

  1. Sandman, Aloha 300' says:

    Sure is a great time to enjoy the weather. The air is heavy with spring blooms. The warm sun feels good on the skin and I like it.

  2. Joshua says:

    I can get behind some 75 and sunny days in April, but 70 at 8:00 am is disgusting. Can’t wait to get today and tomorrow out of the way.

    • Sifton says:

      LMFAO!! “disgusting”……..way to over react, geez!!

    • Joshua says:

      Seriously, it feels gross to me. I had the AC on in my car on the way to work. I just went out for a little break, and it actually feels pretty good out.

    • Gesh. For air that only contains 20-25% humidity?
      My definition of disgusting includes areas east of the rockies, but not here.

    • W7ENK says:

      “Disgusting” lolololol

      Last night when I went to bed at 11 o’clock I still had a light East wind, it was 70 degrees, RH was 11% and the dewpoint was 14F…

      …and it felt AMAZING!!

      Exactly THIS is why I survive winters here, usually without any snow at all. This last winter was a good one, but I’m still glad to see the warm sunshine come back. You will NEVER hear me complain about the sun, just don’t harsh my buzz…

      “Disgusting” lololololololololol

      Don’t be a wimp.

  3. Tyler Mode in Battle Ground says:

    Sunshine and 64 to wake up to on the coast? ?? Sure!

  4. schmit44 says:

    4/29/2014 Oregon (All) Temperature Summary

    High:84 at Highway 42 at Co( 448 ft) & DW5789 Eagle Poi(1463 ft) & Medford Viaduct(1360 ft) & DW9562 Wolf Cr.(1470 ft) & EW4806 Grants Pa(942 ft)
    Low: 63 at CW8242 Ashland(3451 ft)

    High:42 at CW7477 Lostine(7002 ft)
    Low: 14 at ANEROID LAKE #2 (7300 ft )

    Largest Diurnal Change: 50 degrees
    ILLINOIS VALLEY (82/32 ) (1389 ft )

  5. Tyler Mode in Battle Ground says:

    Still very nice here in Newport! Amazing mid 70’s day in most areas. This evening things decoupled and some areas cooled more quickly.

    For now it’s 70 here on the north side of town.

  6. Dave in South Salem (500') says:

    I hope the beaches aren’t too crowded tomorrow. I’m counting on it being mid week to hold off the hoards.

  7. Donna4843 says:

    So,do you think the frost/freeze date is done for the yr or can we still have a frost in May? Thz.

    • David B. says:

      Last frost dates are in May for most of the lowlands, so it is still possible. That said, the odds are definitely against it.

      Quite the dramatic change up here (Bainbridge Island, WA). From frost yesterday morning to well into the 70s (summer temps for us) this afternoon.

      Maybe even warmer tomorrow. No, warmer is not a sure thing for us tomorrow, just a maybe thing. It all depends on the winds. There was very little sea breeze today, which is why it got as warm as it did. If the greater heating in most places tomorrow causes more sea breeze, we’ll stay cooler on the island even though areas away from the water are warmer. I’ve seen it happen before in warm spells.

    • i remember living in Oak Harbor on Whidbey Island, and it would be close to 100 down here, and low 70’s there, and it would feel so warm id be in the front yard with a sprinkler drinkin beers.

    • David B. says:

      North Whidbey really gets blasted by the sea breeze coming in the Strait. Summer highs are often only in the low to mid 60s there. Bainbridge gets much less wind and is significantly warmer in the summer, but still typically about 5 degrees cooler than Seattle.

  8. Muxpux (Castle Rock 175') says:

    I get to start my new landscaping job today. Was just gonna help under the table, but they decided to hire me instead, so that’s awesome. Haven’t worked in the heat (or at all) for a bit now. Should be interesting haha

  9. schmit44 says:

    4/28/2014 Oregon (All) Temperature Summary

    High:71 at MT. YONCALLA(1822 ft) & Hood River(571 ft) & DW5789 Eagle Poi(1463 ft) & Medford Viaduct(1360 ft) & EW4806 Grants Pa(942 ft) & Hayes Hill (US 1(1640 ft)
    Low: 48 at LOCKS(128 ft)

    High:32 at ANEROID LAKE #2(7300 ft) & CW7477 Lostine(7002 ft)
    Low: 15 at CHRISTMAS VALLEY (4360 ft )

    Largest Diurnal Change: 44 degrees
    CHRISTMAS VALLEY (59/15 ) (4360 ft )

    Heaviest Rainfall:
    0.53″ at WANDERER’S PEAK(4350ft)
    0.36″ at MT. WILSON(4002ft)

  10. karlbonner1982 says:

    I wonder if the “Looks more like September” thought crossed Mark’s mind this past day or two, with the warmest air centered west of the Cascades and a very strong east wind through the Gorge and over the Cascades?

    • Garron near Washington Square says:

      I believe this is the classic definition for a NW heatwave. While, there are different definitions for a heatwave, here at least, I think this one is the best fit. 3 or more days of 10 + degrees F above average temperatures. Our average high is around 65, and we’ll be well above that for 3-4 days. Also, on a tech note, 850 MB is actually ~5000′, 1500 meters or exactly 4921.26′. Sorry Mark, everyone makes misteaks…enjoy the heatwave!

  11. karlbonner1982 says:

    Ah – a “May Day Heatwave” this year! That oughtta get the seasonal festivities pumping pretty intensely. Hope the crowds behave this year… 😛

  12. Boydo3 N. Albany says:

    This is great! We get some tropical weather without paying for the plane ride!

  13. Paul D says:

    UGH! 80’s in April? I’ll be inside waiting for it to pass.

  14. The Bad Forecaster says:


    The NWS says the hottest day this week in Tacoma will be 80 before rain returns on late Friday.

  15. Sifton says:

    Tue-Wed; Columbia river here I come!!

  16. Sapo says:

    I can’t wait for this heat, it’s going to be awesome.

  17. W7ENK says:

    YAY!! I can’t wait! ^_^

  18. Aloha Rainshadow says:


%d bloggers like this: