Weekend Update: Friday Evening

Nice snowstorm in progress up in the Cascades this Friday evening.  Looks like Timberline has seen about 6″ so far.  Here’s our forecast:

MarkSnow_MtHoodFcst

The snow tapers off dramatically after midday tomorrow.

Down here in the lowlands, a pretty quiet weekend for weather weenies; just partly cloudy with a few showers Saturday and mostly cloudy with more widespread showers Sunday.

Bad news for skiers though as some of this snow is going to melt.  I expect snow levels back up around 6,000′ from late Monday through early Wednesday, then dry weather.  As a result, I don’t think we’ll see ski areas opening up next weekend, the 23rd-24th.  Of course that’s the weekend before Thanksgiving, which this year is the latest it can be (the 28th).

Let’s talk long range maps…I’ll highlight the similarities.

Big picture appears to be warm system Monday-Wednesday AM, then ridging/drier later next week through the weekend.  Note the 500mb height anomalies from the GEM (12z), ECMWF (12z), and GFS (00z) all line up similarly for Sunday the 24th

anom_ecm_sun24
anom_gem_sun24
anom_gfs_sun24

…possibly another warm and wet system (bad for skiing) for next weekend.  These maps are 8-9 days out.

Then Thanksgiving week, wide variability again, but at day 15-16, all three models develop ridging nearby once again, although it’s quite weak on the ECMWF:

anom_gem_sat30
anom_gfs_sat30
anom_ecm_sat30

These solutions would imply November will remain mild and it’ll be tough to get ski areas open for Thanksgiving.  However, we’ve seen huge swings in that Thanksgiving Week outlook the past few days.  So this is definitely not a sure thing.

Here are the two latest ensemble charts from 00z GFS and 12z ECMWF:

tseries_850t_000-360_Portland tseries_850t_000-384_Portland

The ECMWF sure has it chilly mid-late next week after the cold front slides through Tuesday night or Wednesday AM.  In these charts you can also see the warmer atmosphere next weekend.

The brand new 00z ECMWF coming in right now is almost the same as the 12z.  Strong and chilly offshore flow next Thursday behind the cold front:

ecmwf_apcp_f144_nw

And stronger ridging next Saturday:

500vty_f180_bg_NA

Chief Meteorologist Mark Nelsen

116 Responses to Weekend Update: Friday Evening

  1. runrain says:

    Is there a place I can go, where all the geeks hang out,
    Where they stand holding wind cups way up high,
    Yes they will stare at me, and they will laugh at me,
    I don’t care ’cause it’s on the steps where there’s wind

    Sung to the tune On The Street Where You Live (My Fair Lady)

  2. Marcustheweathernut says:

    Oh yippie a gap east wind event……I can hardly contain myself . Lol….. Nice for the west end of gorge and east county, the rest of us are in the cold fog alllll day!!!!! Blahhhh…….

  3. Rob - Southeast Portland says:

    00z GFS has begun. I’d like to see a similar run to previous 3-4 and then the WRF later as well.

  4. Rob - Southeast Portland says:

    Coldest NAM run yet with tonight’s 00z. 516, -12c line nears BLI. Importantly this may mean deeper cold air into Columbia Basin, stronger cold pool, big time east wind event, maybe damaging? as inversion strengthens late week.

    Considering the past few runs of the NAM compared to GFS have been roughly similar suggests to me that this is a distinct possibility.

  5. Rob - Southeast Portland says:

    Latest Discussion from PDX NWS. Lots of rain coming/AR Event

    AREA FORECAST DISCUSSION
    NATIONAL WEATHER SERVICE PORTLAND OR
    256 PM PST SUN NOV 17 2013

    .SHORT TERM…TONIGHT THROUGH WEDNESDAY…SATELLITE IMAGERY SHOWS THE NEXT SYSTEM DEVELOPING OFFSHORE WITH A SURFACE FRONT JUST CROSSING 140W. THE LOW ASSOCIATED WITH THE FRONT IS NEAR 42N 143W. THE SNOW LEVELS WILL CONTINUE TO RISE AS THE FRONT NEARS…WITH SNOW LEVELS EXPECTED TO BE AROUND 6000 FEET WHEN THE RAIN REACHES THE MAIN RAIN BAND REACHES THE AREA MONDAY AFTERNOON.

    SATELLITE DERIVED PRECIPITABLE WATER SHOWS 1.65 INCHES WITH THIS FRONT WITH A TROPICAL MOISTURE PLUME THAT EXTENDS INTO THE WEST PACIFIC. MODELED TPW ARE AROUND 0.3 INCH BELOW THE SATELLITE ESTIMATE AND MAY BE UNDER FORECASTING THE AVAILABLE MOISTURE. THIS IS STARTING TO LOOK LIKE AN ATMOSPHERIC RAIN EVENT AS MODELS ARE SHOWING EXCELLENT MOISTURE TRANSPORT TO THE PORTLAND FORECAST AREA. HAVE SOME CONCERN THAT WE MAY BE UNDER DOING QPF FOR MONDAY AFTERNOON AND NIGHT…SINCE THESE STORMS HISTORICALLY PRODUCE A LOT MORE RAIN THAN MODELS PREDICT. HAVE INCREASED QPF SLIGHTLY…BUT WOULD NOT BE SURPRISED IF THEY ARE INCREASED EVEN MORE OVERNIGHT. THE HEAVIEST RAIN WILL BE MONDAY AFTERNOON AND NIGHT WITH THE FIRST FRONT…BUT A SECONDARY FRONT WILL BRING ANOTHER ROUND OF RAIN MONDAY NIGHT AND TUESDAY.

    • Rob - Southeast Portland says:

      Correct me if I am wrong, but I do believe in the past after an AR Event/Pineapples that you can get a sudden shift in models 5-7 days later. I’m not saying that will be the case this time or anything like that, but who knows, right.

    • High Desert Mat says:

      Agreed.

    • boydo3 N Albany says:

      Too bad. Pineapples on the ski areas isn’t what we need. But unfortunately, not totally unprecedented. Hope things start to turn around and stabilize to some cold rain down here and a building snow pack in the mountains.

  6. Randy says:

    Anyone see the latest model with the arctic high dropping south into our area late next weekend? Looks like sub freezing highs and lows in the single digits.

  7. JJ78259 says:

    Heading home from the race in Austin my wife said it was 91 out, not bad for November. I guess they are playing volleyball in the pool we adapting well to the new environment .

  8. W7ENK says:

    Peoria, IL was just wiped off the face of the planet by a massive tornado. My Dad’s Vietnam Vet friend who lives there is missing and unreachable!! 😦

    • Lurkyloo says:

      Oh, no … 😦

    • Rob - Southeast Portland says:

      The east side of Peoria towards the Tazewell-Woodford border was hit(The Washington, IL Tornado). Peoria itself was not wiped off the map. I have no idea where you heard this it is not true.

    • BoringOregon says:

      So sry.. Looks like tons of E4 Tornado’s over there?

    • BoringOregon says:

      EF4

    • W7ENK says:

      Thanks for the sensitivity and compassion for these people who may have very likely lost everything, including their lives, Rob. It’s so nice to know that you care. I’m sorry I didn’t take the time to specify that it was only East side of Peoria, ya know, where my Dad’s friend’s house is. I’m sure if they’re still alive, that destinction between East Peoria and West Peoria means everything to them right now.

    • Rob - Southeast Portland says:

      Where did I at any point show that I didn’t care? You’re off your rocker dude. I never said anything at any point that shows anything you’re referring to towards me. If you can’t keep your emotions in check you may want to stay off the Blog. Jeez

    • W7ENK says:

      BWAAHAHAHAAA!!

      Pot, meet kettle. Please take note of the color.

      See ya!

    • Rob - Southeast Portland says:

      Um, okay? You’re simply too flaky too often.

    • Mark Nelsen says:

      You DID say it was wiped off the face of the planet Erik. Which apparently wasn’t true?

    • Mark Nelsen says:

      And we HAVE had an “emotions in check” issue here in the past. How about you two just send emails back and forth to each other instead of here on my blog???

    • Rob - Southeast Portland says:

      I have no idea what I possibly did wrong. Sorry, I won’t e-mail I am not interested in drama.

      ….and we move on

  9. Rob - Southeast Portland says:

    12z EURO
    http://www.cascadeaccess.com/~mnelsen/Models/ecmwf500mb_ecmwf.html
    Rinse/Repeat from 00z. Maybe slightly cooler Wed-Thu as offshore flow is developing becoming strong.

    12z GFS/WRF essentially a rinse repeat. I think the biggest story coming up for those in/around PDX metro will be the coming east wind event and strengthening inversion.

    12z GEM goes nuts with the east wind, looks very strong Friday – Sunday.

    • Ben T says:

      So the very cold is gone again?

    • BoringOregon says:

      Huge, pds storm out break mid west looks crazy!!

    • capkirk45 says:

      Need the components in place for an event.. one of those is a cold pool of air in the Basin, which is now setting up that way. We’re not at a time of year when an overriding storm from the West/Southwest can come along and mix with that cold source flowing out of the Gorge. Nothing is showing up w/ that scenario, but one of the key elements appears to be setting into place.

  10. Marcustheweathernut says:

    12z euro….. Mon storm…… Tuesday showers…. Wed… Drying and cooler with east wind?? Thursday- end of run…. Death ridge!!!!! Nothing exciting blah….. On to December!!!

    • High Desert Mat says:

      Kind of reminds me of how the weather was before the big Dec ’08 occurrence. Looked like nothing was happening with no snow even up at ski areas then bam, models trended fairly consistent out aways. Hmmmmm, maybe we just need to get past the next 3 weeks.

  11. paulbeugene says:

    In NYC…a week ago I was freaking out about Euro advertising a major early season snowstorm for the NYC area, now in slight risk
    SPC category for severe thunderstorms. High risk for tornadoes in Indiana (>30% chance of EF2 E5NWYXtornado within 30 miles of given point)

  12. Rob - Southeast Portland says:

    Well, I wasn’t really expecting this, but shockingly the 6z GFS has come to an agreement with the NAM. It is by far the coldest GFS run we’ve seen in handling the trough next week. Also, this is the first time the GFS has followed the NAM which had been showing to simply be too cold compared to in actuality what had really occurred which has been watered down troughs and not really that chilly.

    6z GFS has 850mb temps -5c TTD, -9c BLI. While this isn’t really a big deal, and no, it’s not going to snow except for possibly far northern Washington IF there is any moisture, what this could mean is modified arctic air filters into north-central Washington/Columbia Basin, a stronger cold pool, and bigger east wind regime after Tuesday for the Gorge and east of I-205. 850mb temps warm significantly west of the Cascades with +11c to +13c over PDX. With this and a strengthening inversion perhaps a very strong east wind event is on tap too.

    • alohabb says:

      what do temps look like in PDX with that scenario? Colder than advertised?

    • boydo3 N Albany says:

      Valley will probably get socked in unless that off shore component really gets going. P town gets the east wind for a couple clear and cold mornings..

  13. schmit44 says:

    11/16/2013 Oregon (All) Temperature Summary

    Warmest:
    High:58 at EW3367 Coos Bay( 98 ft) & CW6811 Grants Pa(947 ft)
    Low: 50 at LINCON Lincoln C(187 ft)

    Coldest:
    High:23 at HOWARD Mt Howard(8150 ft)
    Low: 15 at HOWARD Mt Howard (8150 ft )

    Largest Diurnal Change: 24 degrees
    Worden (48/24 ) (4080 ft )

    Heaviest Rainfall:
    2.08″ at Mount Hood Meado(5249ft)

  14. Rob - Southeast Portland says:

    00z GFS/GEM runs the conclusion I come to is after the front Tuesday that ridging is the main dominant theme and secondly east wind(and perhaps lots of it) with what could be the first prolonged cold pool developing over the Columbia Basin.

    00z WRF begins to develop east wind sometime Tuesday night after midnight into early Wednesday morning as colder air filters southward out of British Columbia into north-central Washington and persists until Saturday(maybe longer).
    http://www.atmos.washington.edu/~ovens/wxloop.cgi?mm5d2_x_slp+%2F%2F%2F3

  15. Rob - Southeast Portland says:

    00z EURO
    http://www.cascadeaccess.com/~mnelsen/Models/ecmwf500mb_ecmwf.html
    Trough may be slightly colder after the cold front Tuesday, especially Olympia northward. Really cold in British Columbia. This makes 3 consecutive runs that look very similar. Then ridging and offshore flow ensues afterwards. Cold air is scoured out of British Columbia and Alberta. Even Yukon warms significantly. I would say there is good agreement with the EURO now the next 3-5 days.

  16. Marcustheweathernut says:

    Does anyone have model runs from dec 08???

    • Benjamin (West Salem) says:

      Those would be interesting to see for sure! I did however, take a look back at the Dec 2nd blog post from that year just to see what the comments were like.

      • Ryan says:

        Yea I wish Mark could resurrect the posts between Dec 2nd and Dec 24th. I’d love to read them! Not sure why they’re missing.

    • Timmy_Supercell (Klamath Falls @ 4200') says:

      It seems models is the one single thing we don’t have archives of. I’ve searched for a while and found nothing. The good ‘ol “right click and save” tactic might work next time… :XD

    • Marcustheweathernut says:

      Unfortunantly the blog was down from dec 3rd- 22… I asked about that a couple of years ago……

  17. Marcustheweathernut says:

    Dec 08????? Lol only dreaming 🙂

  18. It’s amazing how the models change! Not too long ago, the GFS was showing a pretty strong east wind even starting now and lasting for a couple days…that’s completely gone and we have decent onshore flow right now!

  19. Ryan says:

    I like the recent posts! Let’s hope it holds up!

  20. Rob - Southeast Portland says:

    FWIW, 00z NAM is nearly identical to the cold 18z run…. Probably just showing it’s cold bias, but… who the hell knows I mean the EURO is clearly suggesting a signal for a possible even colder solution…..

    • BoringOregon says:

      Guess these model riding things, can make you go crazy??

    • Rob - Southeast Portland says:

      If you did ride the models, hanging onto every single run, sitting at the edge of your seat living or dying by what you see, and allowing it to affect your mood becoming emotionally invested in them, yeah that could make you go crazy.

      I’d hope no one does this.

    • BoringOregon says:

      No no not me. But I guess I’m not the only one that does not have a life tonight. Reading the comments above this???

  21. Rob - Southeast Portland says:

    WOW!

    12z EURO Ensembles are EYE-OPENING to say the least, especially Olympia northward.

    Several members are cold, and a few very cold going full retarded with a major arctic blast. Incredible variability after day 5. The main precip zone will be narrow with a sharp temperature gradient, but where does it setup. Imagine if it’s Eugene – Roseburg, then you introduce cold Gorge outflow. It would be feet of snow nothing like dreaming. I believe what we are seeing unfolding or may unfold is the classic battle of the northern polar jet vs southern branch of the jet. Go northern! At the very least this gives us SOME small ounce of hope and something to discuss.

  22. Stevens and crystal just opened for skiing

  23. Rob - Southeast Portland says:

    The most exciting possibility if we’re that ridgy is perhaps a cold pool might develop over the Columbia Basin with a decent east wind regime, but that means inversion season for those away from any offshore flow.

  24. Kenny says:

    The new 12z GFS Ensembles. A few members show arctic air towards the end of next week.

  25. Jethro says:

    12z WRF-GFS time-height section showing 40-kt winds for UAO Monday night. Still plenty of time for that to change and leave us with the usual 25-30 kt. gusts.

  26. I don’t what all the whinings about. 12z euro cooler, should build snowpack in WA cascades. Looks like turkey day Skiing for at least baker, Stevens, crystal

  27. Ben T says:

    Well it appears nothing exciting is going to happen in November. December it is!

  28. ocpaul says:

    brace yourself, for the mediocrity

  29. Rob - Southeast Portland says:

    The Sun is about to complete it’s polarity reversal cycle that occurs every 11 years, so last time was the Winter of 2002. That Winter I believe was HORRIBLE. Winter cancel 😀
    http://www.foxnews.com/science/2013/11/12/sun-magnetic-field-will-flip-soon-video/?intcmp=obinsite

    • Lurkyloo says:

      “Winter cancel.” Whaaat? Come on, Rob! You can’t hibernate the rest of the season like W7 is apparently doing. Poose cannot be the only optimist around here …

      Wait, you were just making a funny, right? I’m a little slow on the draw sometimes.

  30. schmit44 says:

    11/15/2013 Oregon (All) Temperature Summary

    Warmest:
    High:59 at BROOKINGS( 79 ft)
    Low: 46 at WYETH(102 ft) & Astoria(0 ft) & RUFUS(185 ft) & John Day River B(305 ft)

    Coldest:
    High:24 at Timberline Lodge(7001 ft)
    Low: 8 at Horse Ridge (US (4160 ft )

    Largest Diurnal Change: 35 degrees
    Lorella (45/10 ) (4160 ft )
    CHRISTMAS VALLEY (45/10) (4360 ft)
    Horse Ridge (US (43/8) (4160 ft)

    Heaviest Rainfall:
    1.70″ at NORTH FORK(3120ft)
    1.24″ at TIDEWATER(2035ft)
    1.21″ at HEBOWX Mt. Hebo(3160ft)
    1.20″ at BLAZED ALDER(3650ft)
    1.14″ at CEDAR(2220ft)

  31. Kenny says:

    The new 12z EURO is trending colder now. Here are 850 temps for Wednesday at 4am.

    • Kenny says:

      I meant new 00z EURO.

    • High Desert Mat says:

      Not that I buy any credibility to ur posts Kenny since u wont post where ur at or who u really are but I do like the sharp contrast on that map over in Montana from luke warm to very cold in just a few miles.

    • High Desert Mat says:

      Goes from about 0 degrees Celsius to about -14 degrees in what I would think quite the arctic front. Too bad that’s not for northern Oregon.

    • Kenny says:

      I am from Portland.

    • Lurkyloo says:

      Kenny is in the Witness Protection Program.

      Just a jab, Kenny! What part of Portland? We don’t need exact coordinates … 😉

  32. That cutoff low under the Rex ridge on the ECMWF looks like it might be close enough to stir up the atmosphere and prevent inversion. Could we see the rare feat for this time of year: a day or three with sunshine, offshore flow, and WARM temps in the lowlands? (by “warm” I mean 10-15 degrees above average)

  33. Rob - Southeast Portland says:

    Thanks for the update, Mark.

  34. schmit44 says:

    Looks like a typical November this year.

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