First Hot Weather

SnapshotIt’s very gratifying to take 3 days off work, come back, and find almost the exact same forecast you left the week before.  That’s the case tonight.  The cold trough that over the weekend moved through the Northwest is now into the Northern Rockies.  An upper-level ridge of high pressure is developing just to our west and it moves directly over the West Coast over the next few days.  This gives us another round of downslope easterly wind.  Of course in the warm season, this is a hot wind so today’s 68 degree high will be just a memory by tomorrow afternoon.  Remember that a couple weeks ago we went from 59 to 81 in just one day in the same quick switch from onshore to offshore windflow.  It appears that a thermal trough develops over the coastline by daybreak, then shifts over the Coast Range later tomorrow afternoon.  That gives a brief period of offshore wind even to the beaches in the morning.  That’s why I had such high temperatures in the Coastal forecast tonight.  Inland temperature forecasting is a bit simpler.  850 mb temp of +15 to +16 with "perfect" offshore flow (tomorrow), can give us as high as 90-91 at PDX.  However, I think the wind may be quite breezy even all the way to the airport, which can reduce heating, so I left it at 88.  Wednesday should be warmer since we still have easterly flow in the morning, then it goes calm in the afternoon.  But still no onshore flow at that point, so 91-94 is a good bet then.  A decent, but not major, marine push for Thursday drops us down into the mid 80s.  Same thing for Friday with a few degrees more cooling.
The weekend looks interesting with a sharp trough developing way offshore Saturday, then swinging onshore later Sunday.  That setup will pull the thermal trough back over the westside or at least over the Cascades for a warmer day.  Then when the trough arrives sometime later Sunday or Monday, we get a major marine push west of the mountains.  This will probably be one of those 20-25 degree one-day temperature drops.  Also, it can be a severe thunderstorm pattern east of the Cascades too.  Enjoy the warmer temperatures the next few days…I know my freshly sprouted corn and cucumbers will!  Mark

32 Responses to First Hot Weather

  1. AtmosphericWrath -Southeast Portland- says:

    I topped out at 87.4F Currently 83.8F. E wind still breezy 15-25mph+. Assuming the thermal through remains over/near the Coast Range overnight the E wind should persist throughout the night. That will keep the temps up in the mid 60’s to low 70’s especially E of I-205. If the thermal trough hangs up over the valley tomorrow I’m going with 89-93F. Really tricky depending on how soon the thermal trough begins to push E with the subsequent light onshore flow from the SW filtering in behind it.
    Rob

  2. Derek-West Gresham says:

    That east wind no doubt held the temp down..shouldnt be a problem tomorrow. I am going for 90 still, even that could be too high as the GFS has backed off the heat slightly for tomorrow.

  3. Gregg-Troutdale says:

    Only hit 83 here today, too much wind held it down. My station in Hillsboro hit 87 with only light E winds.

  4. Jordan-Kelso says:

    Temp hasn’t beem rising alot here, but the dew point is sure plummiting. KLS

  5. Jesse-Orchards says:

    Looks like Mark left a 92 for tomorrow in the updated 7-day. We’ll see, but it might be “close but no cigar”. 88 was widely predicted today and it looks as if many areas will top out at 85 or 86 at best. My temp peaked at 86.1 about 20 minutes ago and now is back down to 85.4, may go up again but not much higher than 86 most likely. 90 may happen tomorrow, but if it doesn’t we may have to wait well into June for our next good shot looking at the long range.

  6. Andrew---Ellensburg, Wa and Portrland, Or says:

    Little cooler here today than places on the west side. Currently sitting at 81 degrees. However, that should change come tomorrow. Here is my forcast for ellensburg:
    Wednesday: 89
    Thursday: 91
    Friday: 93
    Saturday: 90
    Sunday: 92
    Monday: 75—cooler

  7. Jesse-Orchards says:

    Looks like PDX stayed at 84 the last two hourly reports, heating for today is beginning to peak, most of us should see our highs within the next 2-2.5 hours. I think 85 or 86 is all most of us, including PDX, will muster today, maybe 87 if and where the wind dies down.

  8. Gregg-Troutdale says:

    81.5, E wind 19 gusting to 26. Have the AC set at 68.

  9. Jesse-Orchards says:

    I’m at 83.8 here now, 90 is looking remote, considering I’ve now been around 83 for nearly an hour.

  10. AtmosphericWrath -Southeast Portland- says:

    84.7F here now. E wind 20-30mph+

  11. Sean (Lebanon, Indiana) says:

    Rob – I’m not seeing any real signs of instability on the westside of the cascades. As Mark mentioned that the eastside may need to be watched though in the next few days.
    Yes, I definitely like warm evenings and sit out and watch the lightning bugs. Been pretty humid here of late (dewpoints have been in the middle 60s) during the evening. So average lows have been hanging around 60-65 at night.

  12. Jesse-Orchards says:

    It seems to be getting better now. I am now up to 83 here. I went through about 20 minutes of steady warming to get there, but now it has plateaued off again for the past 15 minutes. Not the insane, out of control warming I would like to see to go for 90. PDX is up to 82 now though with offshore flow at full tilt, just had an E wind gust of 26 mph this hour.

  13. Gregg-Troutdale says:

    Jesse, try reopening the page. 79.8 here now, have climbed nearly 5 degrees since 11:37.

  14. Jesse-Orchards says:

    Okay, is anyone else having as much trouble with typepad as I am. It keeps taking forever for it to post my comments, so long in fact that I think the comment is lost so I retype it, then suddenly it posts both of them.

  15. Jesse-Orchards says:

    You like those warm and windy nights huh Rob? I hope the wind goes calm allowing me to drop back into the 40s tonight, which is likely for my area, makes for much more comfortable sleeping. I think 90 is a long shot tomorrow. I’ve been at 81 for almost an hour now, was 81.2 at 11:40, now am 81.8 at 12:48, not as much warming as I was expecting. We just aren’t far enough into the warm season and this ridge isn’t anomalously strong enough to just easily pop us up into the 90s. It often seems to me with these downslope warming events the initial warming occurs fast, leaving most areas within 5 degrees of the high by noon or so, which is why I’m holding with my prediction of 86. Give it another three weeks or so, then a ridge like this will bring us some real heat.

  16. Jesse-Orchards says:

    You like those warm windy nights huh Rob? I personaly hope the wind goes calm overnight and I fall back into the 40s, which is likely for my location, makes for a much more comfortable sleep

  17. AtmosphericWrath -Southeast Portland- says:

    80.2F here. Quite gusty E wind 20-30mph which will stir the air a bit too limiting the potential max temp from this offshore flow. I’m hoping the E wind persist albeit lightly throughout the night so we start out Wednesday in the upper 60’s to low 70’s. Also any chance of t-storms Sunday, beyond?
    Rob

  18. Jesse says:

    I’ve been at 81 for the last half hour, it seems my heating has slowed for the time being at least.

  19. Jesse says:

    Haha, Dave Salesky was just up on the “weather deck” and was stating the thermometer up there read 91 degrees when every other reporting station in the area is still reporting mid-70s to around 80. That’s almost as bad as last summer when Matt Zaffino actually gave creedence to that obviously erroneous report of 118 degrees in the Central Willamette Valley. News Channel 8 is so sensationalistic about these “heat waves”, they totally blow it out of proportion, I can’t believe Zaffino was calling for 94 Thursday, does he even look at weather maps. I think we’ll be lucky to hit 90 at all this week, NWS dropped their forecast highs away from 90 this morning and with current temperature trends I think 86 or 87 is looking much more likely today.

  20. Gregg-Troutdale says:

    77.5 now.

  21. Gregg-Troutdale says:

    75.0 already here w E winds at 24 gusting to 32.

  22. Jesse says:

    Hmm, looks like PDX is only at 64 with light westerlies. I’m sure it’s just a matter of time before the offshore flow kicks in, but it’d better soon, or else we’ll have trouble cracking 85 today.

  23. Jesse says:

    Hmm, 64 degrees still at PDX with light westerlies. I’m sure it’s just a matter of time before the wind switches over to easterly, but it’d better soon or we won’t even crack 85.

  24. AtmosphericWrath -Southeast Portland- says:

    TTD-DLS gradient increased to -4.9MB.
    http://wxweb.meteostar.com/meteogram/link_pdiff.shtml?choice=KTTD+KDLS
    72.1F here. E wind 15-30mph
    Seeing some impressive downslope E winds occurring now.
    Larch Mountain in Washington. E 18 G@ 48mph
    Rooster Rock E @35mph
    Nearly mirroring our winter time E wind situations.
    Rob

  25. AtmosphericWrath -Southeast Portland- says:

    63.0F now. E wind 10-15mph.
    TTD-DLS gradient now a light-moderate -4.5MB
    http://wxweb.meteostar.com/meteogram/link_pdiff.shtml?choice=KTTD+KDLS
    Rob

  26. Tyler in Vancouver says:

    Finally picked up an east wind at TTD. I’m headed to work in Longview, prob no east wind there at all the next few days.
    Tyler

  27. Tyler in Vancouver says:

    Well it’s nice to see the offshore flow starting. Check out the obs at Larch Mountain in Washington.
    At
    3:09, 44 degrees, W wind at 4, humidity 99%
    4:09, 60 degrees, SSE @ 5, humidity 99%
    5:09, 62 degrees, E @19, humidity 45%
    Nice sunny and calm here, 47 degrees.
    Tyler

  28. AtmosphericWrath -Southeast Portland- says:

    Thanks for the update Mark.
    Good morning guys. Well I started out quite chilly with 42.8F this morning. On mornings like this sometimes you have to remind yourself that a 43-47F temperature swing is in store for today.
    TTD-DLS gradient is now at -3.5MB
    http://wxweb.meteostar.com/meteogram/link_pdiff.shtml?choice=KTTD+KDLS
    A very light easterly breeze has developed here. I’m looking forward to those warm breezes today. Looking forward to see how things play out with the trough digging in Sunday. Have a good one.
    Rob

  29. Gregg-Troutdale says:

    Thanks for the update Mark!!!!

  30. Derek-West Gresham says:

    Yep, interesting forecasting days ahead. Maybe even a t-storm west of the cascades.. 🙂

  31. Jesse says:

    Ha, finally, I was first!

  32. Jesse says:

    Thanks for the update Mark!

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