Windy Afternoon and Some Weekend Showers

Today was the windiest day in about 3 weeks in the Northern Willamette Valley:

Combine that with clouds, rain a good chunk of the day, and cool temps and it sure felt more like early April rather than late May.

We get rid of the wind tomorrow, but keep the rest.  Although I suppose the showers will be a bit lighter.

A cold upper level trough drops through the Pacific Northwest on Thursday; this is likely to give us a round of heavier cold showers with some hail or thunder.  Lifted Index (measure of stability in an air mass) is right around zero all day Thursday…usually a very good sign, along with a chilly air mass, that we’ll see some active afternoon convection.

As that upper low drops off to the south Thursday night and Friday, we get a very dry northeasterly flow through the lowest 10,000′ of the atmosphere.  This is very similar to a cold and dry northeast flow in wintertime as arctic air moves down behind an upper-level trough.  But since we’re in the warm season, pressure gradients remain light through the Gorge and over the Cascades.  So no gusty east wind.  Just a breezy afternoon north or northeast wind here in the Portland Metro area.  The result will be a 10-14 degree jump in high temperatures and a mostly sunny day. 

Still some leftovers of that northerly flow Saturday for a second nice day, but then it’s back to onshore flow and more cloud cover for the 2nd part of the holiday weekend coming up.  This is where I made a change to the 7 Day forecast this evening.  The trend in models is to push a cool upper-level trough farther south into the Pacific Northwest by Monday.  In fact 850mb temps around 0 to +2 are quite cold for May 28th…I sure wouldn’t camp in the Cascades Sunday and Monday unless I had some solid sleeping bags, gloves, and a hat to wear overnight.  One more reason I don’t mind working Memorial Day Weekend most years.  This year I’ll be here Sunday and Monday. 

Each model and model run has been a bit different, but the trend is still there for a downhill slide weatherwise Sunday and Monday.  I’m not real confident we’ll actually see measurable rain here in Portland, but it’s far safer to go a little pessimistic on a big holiday weekend and be surprised by decent weather than have things turn out the other way around.  Here’s a graphic I used on-air tonight, the warmer temps refer to Friday and/or Saturday, the coolest temps on Monday:

Chief Meteorologist Mark Nelsen

20 Responses to Windy Afternoon and Some Weekend Showers

  1. Rosie Olheiser says:

    Rain last nifgt turned to snow. Ground is all white as is trees. Still snowing mixed with rain, Love La Pine

  2. runrain says:

    Thunder Happy Valley. Maybe couple miles east of here at Hoodview Park. Four high school softball state playoff games have been halted due to the thundershower.

    • runrain says:

      SECOND stroke of lightning, moving east towards Boring. Poor Crater High. All the way up here from Medford! State rules require 30 min wait from the last rumble of thunder.

    • runrain says:

      3rd.

  3. ThunderCloud - North Plains says:

    It’s extremely gusty here right now, and it has been all day. A couple quick showers too but nothing too substantial.

  4. Kassie97222 says:

    ITS RAINING ITS POURING… lol 🙂

  5. Mr Data says:

    Thanks Mark for your thoughts and observations even though the more *mature* members of Western Weather were discussing this pattern a week ago while this blog was deader then a mummy’s tomb.

  6. Garron near Washington Square says:

    I guess I can tolerate a few more weeks of the grey cold conditions a little better this year. At least we got a bit of a break. I wish we could transition into the warmer weather rather than have 55 D/F, then hit 90+ 2 days later, then back again into the 50’s. Lets just say it’s been a banner year for cold/flu/allergy medication sales the last month or so.at my store.

    • Mr Data says:

      Me included in that.

    • Mr Data says:

      Also I wasn’t here in 1993 OR 1994 so I cannot remember something I wasn’t there for.

      January 1997 was the only year that it was dark early enough (due to storms) that all the street lamps came on by 4:00pm and everyone had their headlights on.

  7. Jbpdx says:

    Tick tick tick as the forecast deteriorates. Accuweather was right last weekend showing at least 2 weeks of crappy weather here. Again I say pathetic and frankly unbelievable that a part of the nation can have such consistently stubborn lousy weather. When I eventually get moved to the nice hot sunny desert, my years here will be just one bad memory.

    • chris s says:

      Jb, you cant possibly have grown up here or lived here for very long. This type of weather is not uncommon for this area this time of year, sure some years are a little worse than others, but your posts make it seem like we should be 80degrees and sunny starting in april. Not trying to be mean or anything, but why do you live here then if you are so miserable??? We have had what like 5-6 80 degree days already this spring, 2 weeks straight of dry weather, many many days in the 70’s, etc. 🙂

    • Mark Nelsen says:

      We’re right beside a very cold ocean (for this latitude) = lots of clouds and occasionally drippy weather in spring.

  8. bgb41 says:

    5/22/2012 Oregon (All) Temperature Summary

    Warmest:
    High:75 at Ontario Municipa(2188 ft)
    Low: 56 at BULLY CREEK RESE(2500 ft)

    Coldest:
    High:32 at Timberline Lodge(7001 ft)
    Low: 25 at Timberline Lodge (7001 ft )

    Largest Diurnal Change: 31 degrees
    Rome (71/40 ) (4049 ft )

    Heaviest Rainfall:
    1.48″ at DW0237 Lees Camp(699ft)

  9. bgb41 says:

    We have used up all of our “nice weekend weather” passes this spring. Not sure we can pull off another one here.

  10. W7ENK says:

    It wasn’t so bad today…

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