Warm Weekend Is Here!

What a beautiful weekend on the way with abundant sunshine and temperatures topping out between 72 and 82 Saturday, Sunday, and Monday too!  The next chance for any rain would be Monday evening, just a slight chance of a thunderstorm or shower at that time.

The last two years we’ve had to wait until June to see 80 degree temperatures.  This year should be different; I think it’s very likely we hit 80 in most spots west of the Cascades either Saturday and/or Sunday.

Everything is working out as models anticipated this evening.  The baroclinic band of clouds and rain is lifting north, a warm atmosphere is poised to move in overhead tomorrow, and skies are starting to clear.  Due to models continuing to show 850mb temps around +12 to +14 Sunday and Monday afternoons, I figured it was time to push high temps to 80 on the 7 Day forecast.  I could see as high as 83 in the metro area Sunday too since there appears to be very light offshore flow in the lower levels of the atmosphere; you can see it nicely (wind barbs from the east) on the WRF-GFS cross-section from 00z this evening from tomorrow evening through Monday morning:


You can see a total lack of low-level moisture from late morning tomorrow through Monday night…lots of sun and bright skies.  Enjoy the best weekend of 2012!

Both our RPM and the WRF-GFS definitely imply some afternoon convection at least over the Cascades Monday afternoon/evening, possibly spreading north Monday night.  With such a warm atmosphere and moist southerly flow, it sure seems possible.  Something to keep an eye on…

There are hints that we get a marine push for Tuesday west of the Cascades (it shows up on that cross-section above too).  If so, temps will be MUCH cooler, but forecasting a big push 4 days ahead of time is tough.

A cold upper-level trough is still forecast to approach the Pacific Northwest the 2nd half of next week, bringing back the normal weather, that would be much cooler with showers.

Here’s the latest 12z ECMWF ensemble chart:

It shows cooler than average weather continuing beyond late next week.  The GFS keeps trying to bring back at least weak ridging for the last weekend of April…here’s the 18z version:

Chief Meteorologist Mark Nelsen

26 Responses to Warm Weekend Is Here!

  1. bgb41 says:

    4/21/2012 Oregon (All) Temperature Summary

    Warmest:
    High:90 at MERLIN SEED ORCH(1064 ft)
    Low: 55 at Roseburg Regiona(525 ft)

    Coldest:
    High:53 at YACHTS Yachats(82 ft)
    Low: 25 at Mazama (4590 ft )

    Largest Diurnal Change: 52 degrees
    CHRISTMAS VALLEY (79/27 ) (4360 ft )

  2. Mr Data says:

    The temp is 74F today……inside the house that is!

  3. Dave in SW PDX (235') says:

    My weather station recorded a high of 76.1°F today… with 80’s in the forecast for Earth Day. Bring it on!

    • Mr Data says:

      Oh! That’s the day you fire up your SUV and BBQ grill to annoy the Liberals and leave every light in the house on and water your lawn every hour on the hour. 🙂 I know bad joke!

      Dad in the late 90s before I even heard of Global Warming watched in interview with Al Gore on TV which showed his office with a whole bunch of computer monitors on and several TV’s all in use with every light in the office on.

      You’d think as rich as Al Gore is he would solar panel his entire mansion and not even USE mainland electricity except in extreme emergencies.

      He can afford alternative energy for his 3 expensive mansions we common people could only DREAM of having and probably won’t have for the next 10 years until prices come down to reasonable levels like Henry Ford did to the automobile.

  4. I would love to hear Mark say (honestly) “Well it looks like the convection from the Cascades will move westward, according to all models right now on Monday at dusk. Expect a large outbreak of powerful thunderstorms from Eugene to Longview across the willamette valley including hail, downpours, and hundreds of lightning strikes per hour, this will probably go down in the record books. Get ready for power outages, and enjoy the natural fireworks. It’s time for the Southerners to get jealous of us!”

  5. Timmy_Supercell (Klamath Falls @ 4200') says:

    Thunderstorm Potential on Monday

    By the looks of it, there seems to be a fairly good chance that some decent convection could fire up along the Valley’s and Cascades on Monday. NWS mentions a strong onshore push, which would help out convective development with all the instability that the warmth is creating. For late April style convection, things are looking impressive, as Lifted Index values are reaching as low as -5 in much of Western Oregon, including CAPE values reaching between 1,000 J/kg to 1,250 J/kg.

    Lifted Index

    Surface CAPE

    Here is part of today’s Forecast Discussion from Portland NWS earlier.

    “MONDAY STARTS OFF SIMILAR TO SUNDAY…BUT THERE IS A SIGNIFICANT DIFFERENCE. MOST MODELS BRING A WEAK UPPER DISTURBANCE NORTHWARD FROM CALIFORNIA DURING THE AFTERNOON. DEPENDING ON THE TIMING OF THIS DISTURBANCE…IT MAY COUPLE WITH STEEPENING LOW-LEVEL LAPSE RATES TO PRODUCE SOME CONVECTION COAST RANGE EASTWARD MONDAY AFTERNOON AND EVENING. ECMWF/NAM/GFS ALL HINT AT A FAIRLY STRONG ONSHORE PUSH NEAR THE SURFACE LATE MONDAY…WHICH COULD ASSIST THUNDERSTORM DEVELOPMENT BY PROVIDING A SURFACE TRIGGER TO GO ALONG WITH THE INSTABILITY. THIS WILL MARK THE BEGINNING OF A TREND BACK TOWARD COOLER AND MORE UNSETTLED WEATHER AS THE WEEK PROGRESSES.” ROCKEY/WEAGLE

    • boydo3 N Albany says:

      But if the low level onshore push happens too quickly or too soon, we lose the surface heating and therefore the instability. It remains to be seen.

    • Mr Data says:

      I was about to ask who is in charge of the thunderstorm season updates but it looks like you get to be (it) with the big R gone.

  6. Lurkyloo says:

    Thank you, Mark, for this glorious day! I know that you control the weather (did you study at Hogwart’s or are you part of the X-men …?) since some people were upset with you when winter kinda fizzled. But you have fully redeemed yourself in my book. Cheers!

  7. Mr Data says:

    Just a quicky note: Today is my birthday and sometime around 2005 or was it 04 that there was a heatwave around my birthday because I had friends over in which we tried to play outside and my parents fired up the BBQ grill but by 3pm we all had to migrate indoors because it was humid too and we were all sweating like crazy.

    We went as long as we could before it was too much.

    There was also another heatwave I think in 2008.

    One thing about this birthday is despite the warm weather not ONE SINGLE tree is in bloom in the neighborhood and on that one hot birthday the trees were in full bloom providing some shade but it was too humid to do any good.

  8. AdamInAumsville says:

    These clouds better burn off quick, or we’re going to have a busted forecast!

    • muttville1 says:

      They’re burnt here in da Couve……….

    • Garron near Washington Square says:

      Sick twisted individual that I am wants to see us only get to 69 today so that we still don’t have our first 70 degree day before we get our first 80 degree day…I know, GET HELP!!!

      @ W7enk, I will be interested to see too with the tomatoes. Hoping that I get some giant cherry tomatoes by pollinating the large ones first, or maybe some Cherokee Purple Roma’s.

    • AdamInAumsville says:

      Clouds are hanging on down here in the valley, but visible satellite shows them slowing burning off west to east.

    • Mr Data says:

      They are gone but Mom said while I was sleeping it was socked in with fog.

    • Mr Data says:

      I meant to say after I woke up around noon since I couldn’t sleep last night she told me most of the morning was fogged in so it looks like I didn’t miss the beautiful weather!

      Today so far is very wonderful and I think we all deserve it after the crap we went through.

  9. Muxpux (Castle Rock 175') says:

    Gettin ready to go ride horses today, clouds breaking up here, my friends with the horses are above the cloud deck

  10. Kassie97222 says:

    Did I read a slight chance of thunderstorms or showers on Monday??? I like that… Milwaukie kinda missed out on the crazy thunderstorms the other day…

  11. bgb41 says:

    4/20/2012 Oregon (All) Temperature Summary

    Warmest:
    High:83 at MERLIN SEED ORCH(1064 ft)
    Low: 54 at Union Jct(2700 ft) & DW4122 Eugene(423 ft) & AL7HY Cottage Gr(1001 ft) & DW2789 Milton Fr(1358 ft)

    Coldest:
    High:40 at Timberline Lodge(6001 ft)
    Low: 27 at Mazama (4590 ft )

    Largest Diurnal Change: 39 degrees
    CRN SITE NEAR RI (72/33 ) (4260 ft )
    CABIN LAKE (72/33) (4560 ft)
    Mazama (66/27) (4590 ft)

    Heaviest Rainfall:
    0.84″ at Astoria Regional(10ft)
    0.78″ at ROCKWY Rockaway(450ft)
    0.64″ at MEARES Cape Mear(1421ft)

  12. karlbonner1982 says:

    So basically we go from near-record to record heat (80-83 in Portland and likely mid 80s for The Dalles) to a troughy pattern with 850mb temps in the -2 to -4 range for a couple days. That’s a snow level of 3,000 feet folks. And likely high temps in the mid to upper 50s west of the Cascades unless there is a TON of sunshine. This is almost the most dramatic swing in temps you can ever get in the PNW. Hmm…could we find a way to get next week’s 850s down to -5C, so we could have a 30-degree drop in temperature instead of “only” 25 ?

  13. bgb41 says:

    So glad we are going to break the trend of waiting till June for an 80

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