82 in Portland Today: Possible Thunder Tomorrow Evening

10pm Wednesday

What a day!  Temperatures reached into the lower 80s today with our first real taste of late spring/early summer weather.  PDX officially hit 82, the warmest day since late September

It appears that Medford was the warmest spot in Oregon (of the official METAR sites) with a high of 90 degrees

We did this with a relatively humid atmosphere, morning clouds in the valleys, and very little offshore flow.  You can see how we could be close to 90 in this pattern with dry offshore flow.  That happened on this date in 1992.  We hit 89 on that day and the following one.  I remember that hot weather spell; my first spring living in Portland and sitting on a very sweaty MAX train coming home from a downtown job.

The warm weather means we hit our first 70 AND first 80 degree day together, which hasn’t happened in the past in Portland.  Here are a few other weather facts for you:

Tomorrow we start sunny except in the southern Willamette Valley where some low clouds might come in off the Pacific Ocean.  Then things get interesting in the afternoon.  Models have consistently been showing convection breaking out over the Cascades & Coast Range, then popping up over the valleys too.  Each model is slightly different, but they ALL show very low lifted indexes, abundant CAPE, and precipitable water values well above 1″.  This means we have a POSSIBILITY of seeing a strong thunderstorm anywhere from the Coast Range to the Cascades, but not everyone will see one.  They are always tough to forecast.  The evening WRF-GFS and our RPM imply most of the action stays near/over the Cascades in the south-southwest flow aloft.  I’m not sold on that, but I also don’t see a setup like the June 4th, 2009 event which brought damaging wind to the metro area from a line of thunderstorms.  That event was the last time we saw a Severe Thunderstorm Watch west of the Cascades.


Yes, that’s 8 years back.  We don’t get damaging thunderstorms west of the mountains very often!  In early August 2014 severe storms developed over the North Cascades and north-central Oregon, but a watch only extended up to the Cascade crest as you can see on this image:


For now SPC has part of our area under a MARGINAL threat for severe thunderstorms tomorrow:

Beyond tomorrow evening/night, we’ve got a cold front coming through Friday morning followed by light showers the rest of the day and Saturday today.  Sunday through Tuesday looks pretty nice with typical May clouds and sun mixed.  Note the ECMWF ensemble precipitation product shows little/no rain from Saturday through early next Wednesday.  This is quite an improvement over last week!

We’ll be watching the radar and trends closely tomorrow and I’ll keep you updated.  Don’t forget to follow us on Twitter and Like us on Facebook.  I update info more frequently there.  You see those posts over to the right.

Chief Meteorologist Mark Nelsen

36 Responses to 82 in Portland Today: Possible Thunder Tomorrow Evening

  1. pappoose in scappoose says:

    I hear em out there, wandering about! Gotta get outside!
    (don’t try this at home)

  2. W7ENK says:

    Portland radar just dropped offline two frames ago… perfect timing!! 😂😂😂

  3. GTS1K' says:

    Don’t know about der blitzen, but der donner is here with a vengeance….

  4. cgavic says:

    Cliff Gavic, Sandy, Oregon.
    Sunny with high temps 85, 86. Slight SE wind.

  5. W7ENK says:

    Mt. Hood area:


    234 PM PDT THU MAY 4 2017


    ● Half inch hail and winds in excess of 35 mph will be possible with
    this storm.

  6. Jake-(Gresham near Nadaka Nature Park) says:

    Looking at the regional radar:

    The PDX:


    I’d strongly say the Portland metro area is in for it. I had a feeling this was going to be good. Mark called for 80F yesterday. I made it to 82F and for today he called for a high of 83F. Made it to 84F. While the discrepancy is small. We’re running on the hot and humid end. This could be good. Already had a sprinkle go through and drop the temperature to 82F. Sun is peaking and shining out again now.

    Not saying we get any explosive-like-cells all evening long but I’m betting we see at least one wall / wave go through! Puts da money down

  7. Jason Hougak says:

    Severe thunderstorm warning for northern coast range just east of Astoria but radar shows plenty of activity even west of the coastline.

  8. Scott says:

    Brief thunder and shower in north Salem popped up quickly out of nowhere.

  9. ron says:

    Thunder in Astoria!!

  10. Jason Hougak says:

    Good looking cells along the Oregon Coast at Tillamook

  11. Jason Hougak says:

    Looking exciting out there!👍🏼👍🏼

  12. Too far West and North!

  13. W7ENK says:

    Here we go…

    1259 PM PDT THU MAY 4 2017



  14. Paul D says:

    Got the lawn mowed. Let the thunderstorms begin!!

    • Jake-(Gresham near Nadaka Nature Park) says:

      Same, cleaned up the yard, mowed the lawn, set some fresh Terro poison for the odorous ants going bananas in the backyard / house. Also for the freak’n carpenter ants in the shed shakes fist.

  15. WEATHERDAN says:

    Just had 2 minutes of rain under a mostly sunny sky. 84 with a dp of 61. Lots of accs. Peace.

  16. W7ENK says:

    Lots of ACCAS moving in from the South now, thickening up and starting to blot out the sun at this point. Probably going to cap our heating and keep us below 80.

  17. Roland Derksen says:

    Mainly clear skies here since 7am and temperatures entering the 70’s. I ‘m not wanting to see thunderstorms here- yesterday’s soaker rain of 1.23 inches was wet enough for me.I only saw a maximum yesterday of 59F.

  18. Longview 400 ft says:

    According to the UW radar, cells are working there way up from the southern Oregon coast and heading north.

    • Weather geek in Wood Village says:

      I noticed that too. I also see the flow going from South to North. I think it could be a very interesting afternoon and evening.

  19. W7ENK says:

    Sadly, it looks like everything is setting up too far to the East. Hard to get storms into the Valley off the Cascades when the steering flow has no Easterly component to it. We may get lucky and the inrush of marine air could trigger some storms in the Valley, but that rarely works out in our favor. If anything, Albany/Salem will get hammered, but the storms peter out before they reach Woodburn. Most likely, by the time they make it to PDX metro they’ll be collapsing and just raining out.

    This is just the beginning though, it could be a good, long Summer for this stuff…

  20. pappoose in scappoose says:

    Hazardous Weather Outlook
    National Weather Service Portland OR
    806 AM PDT Thu May 4 2017

    .DAY ONE…Today and Tonight
    Thunderstorms are expected to develop later this afternoon into
    this evening. Stronger storms are most likely over the Cascades
    and may produce damaging hail and strong winds.


  21. Is there a possibility of tornadoes today?

  22. Matthew says:

    You’re right, Mark. I knew it included Clark/Cowlitz and Multnomah/Clackamas counties, but forgot that the line that got agreed to between SPC and the offices impacted kept it east of the metro area. Sorry for the confusion & thanks for the clarification!

  23. Paul D says:

    The weather roller-coaster is back! Please keep your body parts inside at all times 🙂

  24. Matthew says:

    “That event was the last time we saw a Severe Thunderstorm Watch west of the Cascades.”

    Mark – I’m pretty sure there was a watch issued for portland metro area in August 2014

    • Mark Nelsen says:

      I remember that one, when someone died from a flash flood on Mt. Hood right? That was across the northern part of Oregon and the Gorge, but I think it stopped just east of Portland…I could be wrong.

    • Mark Nelsen says:

      I added the watch box images for those two events to the post. You see the box was for over and east of the Cascades, but then since a small part of Multnomah/Clackamas counties were clipped by the box, that set off EAS alarms in the metro area. I remember explaining that on-air.

  25. Boydo3 N. Albany says:

    Well…it feels like its been a long, long time since it has been this warm for a very, very long time (no Trump inflection intended 😉 ).

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