Weekend Outlook & ECMWF Weekly Maps

11:30pm Friday…

A thick marine layer west of the Cascades sticks around tomorrow, giving us another gloomy day with a few sprinkles.  If you want sun head east of the Cascades.

Sunday the onshore flow weakens dramatically.

7 Day

Monday is an interesting day as a weak thermal (warm) surface trough develops right over us.  Not really an east wind situation, but the effect on temperature should be dramatic regardless.  We might end up around 80 degrees Monday.  The other reason Monday is interesting is because some models show a lot of CAPE and below zero lifted index along with the thermal trough.  A very unstable atmosphere.  That plus easterly upper-level flow and increasing precipitable water screams “THUNDER POSSIBLE” to me.  We’ll see how models develop the situation as we get closer.

These maps are actually from the ECMWF 32 day run two nights ago…sorry, a little slow.





They show upper-level heights rising to a bit above normal over the Pacific Northwest over the next month.  Supposedly the pattern of cool troughs moving in to our south will end; which has been very unusual for May.  This tells me we still don’t have any long cold/wet period coming up, at least west of the Cascades.  Rainfall is still a bit below normal here in Portland at mid-month.  We could end up with a drier than normal May.

Chief Meteorologist Mark Nelsen

21 Responses to Weekend Outlook & ECMWF Weekly Maps

  1. Well, that was a nice surprise from you Americans last night! We received a band of showers originating from Washington shortly before midnight. I didn’t get very much at my place but Wolf Read (a name you might know, Mark) reported to me that for a few minutes near his residence (about a mile west) rainfall intensity was at about an inch (or more) an hour. And here I was beginning to think, what a boring month!

  2. schmit44 says:

    5/17/2015 Oregon (All) Temperature Summary

    High:82 at Celilo, East of( 225 ft) & ROWENA(116 ft)
    Low: 58 at Rye Valley(I-84(2230 ft)

    High:40 at MT. HOWARD(7910 ft)
    Low: 23 at DIMLKE (4726 ft )

    Largest Diurnal Change: 43 degrees
    PRINEVILLE 4NW (74/31 ) (2839 ft )

    Heaviest Rainfall:
    1.10″ at TAYLOR BUTTE(5030ft)
    0.98″ at USCRN SITE AT NO(4260ft)
    0.90″ at ANEROID LAKE #2(7400ft)
    0.90″ at MT. HOWARD(7910ft)
    0.75″ at EW6045 Prinevill(2884ft)
    0.70″ at BOURNE(5850ft)
    0.67″ at HOWARD Mt Howard(8150ft)
    0.57″ at CALVERT PEAK(3822ft)
    0.54″ at EW6078 La Pine(4259ft)

  3. Garron near Washington square says:

    These have to be among the hardest days to forecast for high temps and when the sun will come out. I’m sure Mark’s sweating today, probably due to his “warm bias”…lol, It looks “possible” interesting this evening (I give it a 10%chance) if the thunder and lightening keeps moving on up, http://www.cascadeaccess.com/~mnelsen/lightning2.jpg

    • Boring Oregon says:

      CNN- Comunist news network.

    • Dringus says:

      Yes because only communists would put in the news a NASA report. Make a counter argument or drop the hackery. It’s unseemly.

    • gidrons says:

      I’d take that bet. Antarctic ice has been at a record high. Wasn’t the Arctic supposed to be ice free this year? Or was that last year?
      FWIW I don’t deny AGW.

  4. Brian Leroy says:

    cool and cloudy here in seattle the past few days and yet neibours are watering like it’s in the 90’s not sure why, anyways long rang models show some upper 80’s by month end, if it pans out it will be long over due.

    • WEATHERDAN says:

      There are adult education classes in English spelling Leroy. It might be worth your time. Peace.

  5. schmit44 says:

    5/16/2015 Oregon (All) Temperature Summary

    High:75 at UMATILLA( 270 ft) & AC7WN Hermiston(497 ft) & ECHO(758 ft) & EW1140 Umatilla(364 ft) & Pendleton(1100 ft)
    Low: 59 at JUNIPR(359 ft) & ROWEWS(104 ft)

    High:36 at HOWARD Mt Howard(8150 ft)
    Low: 25 at KIRK (4519 ft )

    Largest Diurnal Change: 32 degrees
    KLAMATH BASIN NW (61/29 ) (4200 ft )

    Heaviest Rainfall:
    0.92″ at HOWARD Mt Howard(8150ft)
    0.81″ at DW6879 Union(2792ft)

  6. Boydo3 N. Albany elev. just under 500' says:

    Like a thick, damp blanket out there..
    A hint of color to the west
    Shake out the sheets!

  7. Jason Hougak says:

    Drizzle since Friday evening and has only gotten heavier more like a steady rain now. Seems like I’m at the beach. Of course I need to dig 6 holes for my pole barn I’m building.
    Mark on the post of that downpour over the Blue Mtns I wonder what I-84 was like at Meacham, must have been like the sky was falling!

  8. Boring Oregon says:

    In the paragraph under the weekend forcast it says” We might end up around 80 degrees day.” Just pointing that out.

  9. Hi Mark: Our local forecast is saying “a chance of a thunderstorm” late Sunday evening, so that ties in nicely with your outlook. Very little rain here so far in May (just over a quarter inch), so unless we get some heavy showers/thundershowers, this could become my driest May on record.

  10. schmit44 says:

    5/15/2015 Oregon (All) Temperature Summary

    High:76 at UMATILLA( 270 ft)
    Low: 58 at John Day River B(305 ft) & Celilo, East of(225 ft) & RUFUS(185 ft)

    High:33 at Rim(7050 ft) & ALAKES Haines(7979 ft)
    Low: 30 at ALAKES Haines (7979 ft )

    Largest Diurnal Change: 30 degrees
    UMATILLA (76/46 ) (270 ft )

    Heaviest Rainfall:
    1.30″ at MT. HOWARD(7910ft)
    1.14″ at Rome(4049ft)
    1.11″ at MOON HILL(6100ft)
    0.90″ at SILVIES(6990ft)

  11. Laura in Corbett says:


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