Warm Rain and Hot Wind On the Way

SnapshotBack to work today after a so-so weekend weatherwise.  Forecast was pretty good, but a bit chilly again for early May.  Apparently we’ll make up for that later this week.  Several items of interest:

1.  Rain
Tropical moisture is streaming across the East Pacifc towards the West Coast tonight.  Models bring some of that inland tomorrow for a cloudy and sometimes rainy day in Northwest Oregon and Southwest Washington.  Not much to debate here.  It is strange to have rain forecast at the same time upper level heights near 580dm at 500mb.  The 00z GFS pushes rain north of us soon after daybreak Wednesday, with plenty of afternoon sunshine.  That plus a very warm atmosphere should push us into the low-mid 70s that day.

2. Hot Temps
No argument on the big heat up for Thursday-Saturday either.  Models have been very consistent for the last 24 hours.  Offshore flow begins on Thursday…in fact GFS has the thermal trough out along the beaches already in the morning.  Easterly flow + 850mb temps around +18degC equals a high right around 90 here in Portland.  So we’ll go from low-mid 70’s Wednesday to 90 Thursday…quite  a change.  Then I notice the last few runs of GFS and ECMWF (as of 12z) show no significant onshore push of marine air until Saturday night.  So…another day of even strong offshore flow Friday + 850mb temps of 20-22 degC should give us a high awfully close to 95.  On my chart, I see only 4 days in 9 years during the month of May have seen 850 mb temps above +20.  This will be a very rare hot spell indeed, especially if we do see 2-3 days at/above 90 degrees.  Just think, overnight temps in the city will be quite close to today’s high!  I almost planted some more summer veggies today, but figured it would be better to wait for much warmer soil Sunday or Monday AFTER the extreme and stressful heat has passed. 

3.  Dry May
We’ve seen very little rain this month and apparently very little is going to fall through the 20th based on current maps.  For those of you with freshly planted vegetation, you need to water the next few days…really soak those new shrubs because they’ll be fighting a dry, hot east wind Thursday and Friday.  These plants have gotten used to 55-65 degree days and some drips.

Mark Nelsen
 

20 Responses to Warm Rain and Hot Wind On the Way

  1. Derek-West Gresham says:

    My 2nd setence was kind of vague so here is the corrected version.
    *And if any cape does develop given the oppressive cap it will have to fight against nothing will form.*

  2. Derek-West Gresham says:

    I don’t think we see any precip with this. That low sets up shop almost right overhead and doesn’t allow for any real southerly flow. And if any does develop given the oppressive cap it will have nothing will form. With such hot temperatures some cape will indeed develop, but also like I said that cap isnt going anywhere.

  3. HIO Phil,
    Nah doesn’t appear to show any QPF at all. Well who knows though.
    Good night all.

  4. Rob,
    Were any of the models hinting at any real moisture to go along with the CAPE?
    I seem to remember one of the models showing a weak low off California later in the week. It kinda wandered around off the coast as far as I could tell. I’m not well practiced in model interpetation.

  5. Hellloooo warm front.
    Warm front just passed north of us.
    My temp has risen from 54.7 to 59.0 now.
    South to southwest winds have developed.
    PDX-EUG shows this nicely also.
    http://wxweb.meteostar.com/meteogram/link_pdiff.shtml?choice=KPDX+KEUG
    Increasing to -1.9 mb now
    We are just now on the outer fringes of the warmer air.
    Very soon we will be asking for the 50’s and 60’s to return.

  6. TheTriforce says:

    First of all Mark you didn’t read my mail so I am going to ask you the Silverton Geography and weather question one more time since it puzzles me.
    60F here and cloudy, Hard to believe it’s gonna get HOT coming up. Wow!!!! A monster low and a high pressure rige near the same areas. Weird.

  7. I noticed a few models now throwing around the idea of some CAPE developing around 1,000 J/kg with the heat. Hmmm…..
    Also Mr. Pierce just sent out an e-mail that the latest WRF model is showing temps 37c now. We have a shot at 100F if that verifies. I’m sure Steve will post later in better detail.
    I assume the models are trending hotter due to that freak of nature low out on the North Pacific serving to pump the ridge more so than typically.
    Btw 53.4 here. Hard to believe within 36 hours we will be 35-40F warmer than this! WOW.
    – Dr. Rob

  8. offroadjosh(kila montana) says:

    ya Rob we are worried about flooding in town and in some areas out here

  9. Luvry says:

    Rob, nice pic, btw, in that same illustration, look at the huge bubble of high pressure (technical term) getting ready to explode north over us…from a cold rainy day today to 90 on thursday…I can’t remember swings like this in temp for a long time, just a couple weeks ago we saw lower eighties one weekend and snow the next…now we’re going from drippy 50 to scorching 90 in two days…
    BTW, it’s COLD outside!

  10. Mat ne portland says:

    It seems our snowpack will be severely crippled after this heat wave. The rivers are really going to rise over the next week. Fishing is not going to be good.

  11. It’s a good thing that the low is well out in the Pacific. If it was closer to the coast we could be looking at a May windstorm. From looking at Wolf Read’s site I don’t see any storms mentioned later than mid April in the spring. In the last 25 years I can remember some good soakers in May and June where it rained all day, but not any significant regional wind.
    Josh – Sorry to say that I thought you might have more snow and then you did. I hope the flooding won’t be too severe in town.

  12. Good morning all.
    Well that sounds like a potentially serious situation Josh, hopefully not.
    Tracking the monster low. The low is currently near 160 W, 45 N. moving northeast.
    [Zoomed in map]

    Meteorologically speaking that low is beautiful and still bombing. A really nice looking back bent occlusion has developed and you can just now begin to see the low spinning up. Also looks like a decent baroclinic leaf precip shield has formed. What a freak of nature this thing is.

  13. offroadjosh(kila montana) says:

    gunna be sand bagging(for a low lying area in town) this weekend due to high temps and a high snow pack melting quickly…) gunna be hotttt

  14. Errr..
    Is* this May, or January.
    It’s late…..
    Good night all.

  15. Ok back to my May Monster out in the North Pacific.
    Surprisingly per the NCEP/NOAA 06z forecast map they have it deepening even lower now down to 956mb!
    [NCEP/NOAA 06z Forecast Map]

    Take a loop at the latest grab off the WV Loop imagery!

    What a textbook bomb. Look at the sharp darkening behind the low and the impressive jet streak that has shown itself.
    It this May or January? Unbelievable.
    [Zoomed in map]

    I do not think I’ve ever seen anything like this in May 😮
    – Dr. Rob

  16. TheTriforce says:

    That is DANGEROUS conditions. A motel or hotel for a night or two would be wiser if you can afford it. Ever heard of heatstroke?

  17. Derek-West Gresham says:

    I suspect we will do it Steve! As for heatwaves they are “fun” and all but it sure gets miserable in my house when they happen. Given the lack of AC, the bad insolation, and the heat that lights and video game consoles give off it will be no lower than 90 IN my room by Friday. Perhaps up around 95, which happens sometimes. Not good for sleeping..

  18. Steve Pierce (Vancouver, WA._ says:

    Hey Mark, here is an edit note for your blog entry —
    If we can muster 94 degrees at any time this week, it will be the hottest temp ever recorded at PDX this early in the year. The old record is 93 set on the 7th and 15th of the month in year’s past. That looks like it could be done on Friday. WOW!
    SP

  19. Mark,
    thanks for the update. Hmmm perhaps we will be quite muggy Wednesday into Thursday as well. Bummer that there doesn’t appear to be any chances of convection showing up. Hopefully that changes.

  20. S.D. NoPo says:

    Thanks for the update, Mark!
    I’m sort of looking forward to the ‘heatwave’ (from the comforts of my air conditioned home, that is). 🙂

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