Showers Next Two Days; Thunder Possible Too

11pm Monday…

In general the weather pattern remains quite slow and not real exciting the next week or so.  But tomorrow and Wednesday a cool upper-level trough will edge closer and then right over us, destabilizing the atmosphere.  That leads to afternoon showers both days, especially Wednesday.

This weekend ended up a bit drier than I expected.  We sure expected the mainly/all dry Saturday and Sunday, but then the system yesterday evening and overnight was weaker than anticipated.  As a result; weekend rain totals were pathetic.

PLOT_Rain_MANUAL_Metro

So I’d say this Memorial Weekend was the nicest in 5 years…since 2009.

Back by popular demand…actually there is no demand for it…is the graphic showing our average high temp in late May is similar to late September or early October.  So even though meteorological summer is right around the corner (June), it’s hard to call late May the start of summer here.  This year though it sure wasn’t bad was it?

MarkMemorialDay_StartofSummer

This week the only showers should be tomorrow afternoon, Wednesday, and maybe a leftover shower on Thursday morning.  That’s it for the lowlands.  Either tomorrow or Wednesday could see thunderstorms.  Tomorrow looks interesting as showers build over the Coast Range and then drift out over the valleys.  Both our RPM model and the WRF-GFS from the UW show this…here is the 4km precipitation from the WRF at 2pm:

or_pcp3.21.0000

and 5pm when the showers are moving out over the valleys.

or_pcp3.24.0000

Lifted Index values and CAPE also suggest thunder is possible, although probably the “rumble here and there” variety, not the exciting stuff.

So the message is to get your dry weather activities done before early afternoon tomorrow!

Chief Meteorologist Mark Nelsen

21 Responses to Showers Next Two Days; Thunder Possible Too

  1. gidrons says:

    Let’s see if this works. Intoxicated North Dakotans up close with a tornado. Warning – foul language, but I suppose that’s redundant with intoxicated North Dakotans.

  2. pappoose in scappoose says:

    Thunder in the Land of Gravelly Plains! I’m getting outdoors!

  3. Dave in South Salem (500') says:

    Snoozer day so far.

  4. Hal in Aims says:

    Heavy shower w/hail now….

  5. Garron near Washington Square says:

    I think they covered their bases next “week” by misspelling “weak
    low” in the long ranger. Calling it a week low just in case it lasts all weak!~

    .LONG TERM…NO CHANGES. PREVIOUS DISCUSSION FOLLOWS.
    SATURDAY THROUGH MONDAY NIGHT…THE UPPER TROUGH WILL REMAIN OVER
    THE PAC NW THROUGH THE WEEKEND. SOME OF THE FCST MODEL ENSEMBLES ARE
    INDICATING THAT THE TROUGH COULD DEVELOP INTO A CLOSED LOW ON
    SATURDAY. WILL KEEP A CHANCE FOR SHOWERS AND THUNDERSTORMS OVER THE
    CASCADES THROUGH SUNDAY NIGHT…MAINLY DURING THE AFTERNOON AND
    EVENING HOURS. MAINLY ONSHORE FLOW OVER THE EXTENDED PERIOD SUGGESTS
    OVERNIGHT AND MORNING CLOUDS FOR THE COAST…POSSIBLY PUSHING INTO
    PARTS OF THE INTERIOR VALLEYS. INLAND VALLEY HIGHS WILL LIKELY REACH
    WELL INTO THE 70S OVER THE WEEKEND…RUNNING ABOUT 5 DEGREES ABOVE
    SEASONAL NORMALS. THE UPPER LEVEL TROUGH WILL FINALLY PUSH EAST OF
    THE REGION EARLY NEXT WEEK…BUT ANOTHER WEEK SHORTWAVE MAY PUSH IN
    ON MONDAY. PYLE/HARTLEY

  6. schmit44 says:

    5/27/2014 Oregon (All) Temperature Summary

    Warmest:
    High:87 at ALKALI FLAT(2495 ft) & Rome(4049 ft)
    Low: 57 at Rye Valley(I-84(2230 ft) & Ontario Municipa(2188 ft)

    Coldest:
    High:41 at Timberline Lodge(6001 ft)
    Low: 26 at KIRK (4519 ft )

    Largest Diurnal Change: 45 degrees
    FOSTER FLAT (75/30 ) (5000 ft )

    Heaviest Rainfall:
    0.54″ at DW0380 Sandy(1600ft)
    0.33″ at EAGLE CREEK(732ft)
    0.33″ at DW4118 Sandy(1250ft)

  7. pappoose in scappoose says:

    Look out! Incoming Stray Albino Donkeys may be kicking!

    NATIONAL WEATHER SERVICE PORTLAND OR
    909 AM PDT TUE MAY 27 2014

    .MORNING UPDATE…FORECAST CONCERNS REVOLVE AROUND CONVECTIVE EVOLUTION TODAY. AREA OF SLOW MOVING SHOWERS OFFSHORE SHOULD CONTINUE TO MIGRATE INLAND TODAY. PRETTY STOUT CAP ON THE MORNING SALEM
    SOUNDING…BUT LATER THIS AFTERNOON AND EVENING THE UPPER TROUGH AXIS DRIFTS CLOSER TO SHORE AND THE CAP SHOULD GET MUCH WEAKER IF NOT ERODE. MODEL INSTABILITY PARAMETERS STILL LOOK PRETTY WEAK…BUT
    VARIOUS CONVECTIVE ALLOWING MODELS DRIFT THE CURRENT AREA OF SHOWERS OFF THE COAST ONSHORE LATER TODAY WHILE ADDITIONAL SHOWERS POP THIS
    AFTERNOON FARTHER INLAND. TWO OF THESE HIGHER TIME RESOLUTION MODELS INFREQUENT 50 DBZ
    ECHOES IN THEIR RADAR REFLECTIVITY OUTPUT IN THE CURRENT AREA OF ISOLATED THUNDER COVERAGE…BUT ALSO SPREAD SOME FARTHER INLAND FROM
    ABOUT SALEM NORTHWARD. THEREFORE…WILL EXPAND THE ISOLATED THUNDER COVERAGE IN THROUGH THE PORTLAND METRO AS THE CAP LOOKS TO ERODE ENOUGH LATE TO POP AN ISOLATED T-STORM OR TWO.

    SREF CALIBRATED PROBABILITY OF THUNDERSTORMS HAS BEEN WAVERING BETWEEN 20-40% OVER THE PAST FEW RUNS…AND TYPICALLY 30% IS A DECENT
    THRESHOLD…SO THIS CONTINUES TO SUPPORT SHOWERS WITH MAYBE AN ISOLATED THUNDERSTORM…BUT FEEL WITH DECENT UPPER FORCING AND THE CAP IN PLACE THAT THE ONES THAT DO POP MAY HAVE SOME BRIEF KICK TO
    THEM. /KMD

    • Boydo3 N. Albany says:

      They could have just read Mark’s post and copied and pasted that.

    • pappoose in scappoose says:

      I really like it when there’s agreement on wandering Strays!

    • Garron near Washington Square says:

      I’m hoping for some better organized strays this weekend with the ULL possible becoming a closed low. Maybe get some south-se flow around the low with warmer day time highs. Or, might be time to take a weekend trip into the mtns. around Bagby hot springs for a decent chance for stronger t-storms.

      .LONG TERM…FRIDAY NIGHT THROUGH MONDAY…AN UPPER LEVEL TROUGH
      WILL REMAIN OVER THE PAC NW FROM FRI NIGHT THROUGH NEXT WEEKEND.
      SOME OF THE FCST MODEL ENSEMBLES ARE INDICATING THAT THE TROUGH
      COULD DEVELOP INTO A CLOSED LOW ON SATURDAY. WILL KEEP A CHANCE FOR
      SHOWERS AND THUNDERSTORMS OVER THE CASCADES LATE FRI THROUGH SUNDAY
      NIGHT…MAINLY DURING THE AFTERNOON AND EVENING HOURS.

  8. David B. says:

    Well, it was plenty showery to the north. Even spat a bit at my friend’s cabin in Boston Bar, BC, which is normally rain-shadowed from these spring-showery events.

    Do my eyes decieve me? It looks as if there might actually be a warm/sunny spell timed to coincide with next weekend coming up! Would be nice, though I’m not going to get too excited about it for a couple more days; it could all change.

  9. High Desert Mat says:

    Beautiful weekend over on this side of mts. too. Although the wind is really starting to annoy me. Seems like its windy everyday with a really windy day mixed in twice a week or so.

  10. Garron near Washington Square says:

    This was one Memorial Day weekend that I was actually envious of those out camping and having fun while I worked all weekend. Usually, I don’t take time off to stay around here, until around July 4th. Not summer like, but not too shabby for the PNW!

  11. schmit44 says:

    5/26/2014 Oregon (All) Temperature Summary

    Warmest:
    High:85 at LAKE OWHEE AND O(2400 ft)
    Low: 64 at Rye Valley(I-84(2230 ft)

    Coldest:
    High:43 at Timberline Lodge(6001 ft) & Timberline Lodge(7001 ft)
    Low: 30 at Timberline Lodge (7001 ft ) & Mount Hood Meado (6601 ft )

    Largest Diurnal Change: 41 degrees
    Lakeview, Lake C (75/34 ) (4734 ft )

    Heaviest Rainfall:
    0.55″ at HEBOWX Mt. Hebo(3160ft)
    0.53″ at TILLAMOOK(11ft)

  12. W7ENK says:

    I hope we get some more thunder! 🙂

  13. Mike (Orchards 255') says:

    No weather complaints from me!

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