White Christmas?

Uswhitechristmas_2Don’t forget that whenever I insert images into the blog, you can click on them to get a larger view.  In this case it’s pretty important because it’s making my old eyes hurt just to squint at this image.  Notice how much company the west side of the Cascades has with the rest of the USA.  Most of the country has a pretty slim chance of seeing an inch of snow on the ground on the average Christmas Day.  And now with only 8 days to go, I think the chance for snow is VERY low for Christmas Eve or Christmas Day.  The reason is that the westerly flow with frequent mild Pacific weather systems will continue through the foreseeable future.

System #2 for this week is arriving tonight.  Earlier today it was accompanied by a 986mb (estimate) low.  That low tracks northeast into the Puget Sound area by early afternoon tomorrow.  Normally this could be a high wind threat for inland areas considering that by that time the isobars are lined up perpendicular to the western valleys.  That can be very good for accelerating wind straight up the valley.  BUT, in tomorrow’s case the low has weakened to 990-995 millibars.  You don’t get damaging, or really even strong, wind with a very weak low that’s weakening as it moves inland.  Models have been showing this for days now, so not really a surprise.

System #3 is racing across the Gulf of Alaska and will be here in 24 hours!  This one should have quite a bit more moisture with it.  Also, a much stronger surface low down around 980mb moves onshore.  This low moves into Central Vancouver Island…a bit too far north to give us damaging wind in the western valleys.  But this should give the strongest wind to the Coastline that we’ve seen in two weeks.  Peak gusts of 60-70 mph are likely out there very late tomorrow night.

A cold trough then follows storm #3 for Thursday and Thursday night.  Thicknesses drop to around 522dm and 850mb temps down to around -6 means snow will be quite close!  I put one little hidden snowflake in the 7 day forecast.   It’s cold enough for snow on the hills for sure.    00z NAM says the freezing level drops to right around 2,000′ Thursday and a bit lower Thursday night.  This pattern tends to be awfully dry, but it IS similar to the day after the big windstorm last December.  Remember what happened that day?  A line of showers in the late afternoon moved from the Scappoose/St. Helens area down through Vancouver and into outer N.E. Portland, giving those areas a good 1/2" or so of snow.  So, Thursday and Thursday night needs to be watched closely.

High pressure settles in to our east Friday for flow turning offshore and likely dry weather.

Saturday-Christmas Day returns us to frequent weather systems moving through.  It seems that the 00z models have pushed most of the action a bit farther offshore though…Christmas MAY end up being pretty quiet…(or may not)….Mark Nelsen

135 Responses to White Christmas?

  1. Camas Mom says:

    Sarah – awesome video! We moved from Alameda neighborhood over here – I still miss the old houses. They have so much character.

  2. Lonewolf >Vancouver, WA says:

    Thanks, Sarah. That was fun to see!

  3. Justin (Brush Prairie) says:

    Yes, cool video Sarah.
    We had tons of snow that winter. It would be wonderful to see that again.

  4. Andrew---Ellensburg, Wa and Portrland, Or says:

    Nice video Sarah

  5. Boydo3 says:

    Yeah, it does look ominous. Really starting to rev up. I wonder if it will turn north as per charts or just rip thru? Wish I was at home with high speed instead of this dial up in the coast range! Think I’ll pack the chain saw before I head out in the morning! Keep me posted.

  6. J.R. says:

    so what time should we see the wind at its peak?

  7. Sarah in West Linn says:

    Hi everyone. Since we all enjoy speculating about big snows, I thought you might like to see some video from the January 1969 blizzard in Portland. (I just happen to be editing my family’s original 8mm movies.) It’s a short snippet, only 28 seconds or so, but you can see how it really piled up. This was shot at our house in the Irvington neighborhood. I’m the toddler.

  8. Tornado Aly (Vancouver) says:

    yes, that dry slot is awesome! Hope the low continues on it’s track and doesn’t curve north too much!

  9. yevgeniy/beaverton/hillsboro says:

    that low is really intensifying, maybe just maybeee koin is not wrong after all, personally i think we could see 25mph-35mph sustained with gusts to maybe as high as 55mph
    once again i am not an expert but if that low keeps intensifying and stays south enough i think those winds could happen…

  10. Dr. Rob -Far S.E. Portland- says:

    One more thing I wanted to add. I can’t recall a time where I’ve seen such a monstrous dry slot like this and how it’s morphing along with the low. It’s neat how mother nature continuously puts on a show in one form or another.

  11. Dr. Rob -Far S.E. Portland- says:

    I am very uncertain on any snow. It’s difficult to get snow if we have any onshore influence with the moisture. If we can manage the moisture, but no SW-W-S winds accompanying it then I’d entertain the idea more.
    Wednesdays low is actually now down to 985 or so.
    http://www.atmos.washington.edu/cgi-bin/latest.cgi?fronts-ir
    [WV loop]
    http://www.atmos.washington.edu/~ovens/loops/wxloop.cgi?wv8km_enhanced+12
    IMO the dry slot/low is still moving ESE. It should begin wrapping up soon-overnight. I think it has potential to explode with rapid intensification (972-977mb), but that would just likely swing it far north.
    You know Salem had a 38mph gust earlier and that was with a weak low that was dying/filling around 995-997mb. Granted todays low was off the NW tip of Washington, but I think it’s something to consider especially since tomorrow mornings low will be much tighter and probably strengthening. I think 35-40 perhaps 40+mph gusts are possible.

  12. Boydo3 says:

    Eye of Sauron is apt! Just been on a Harry Potter binge. Windy in the morning especially on the coast where I happen to be working.
    Low snow Thursday but overrunning event is unlikely later since we will no doubt already be in a S. flow on the surface (at least in the Valley). Wish it would tho.

  13. Tornado Aly (Vancouver) says:

    I am still leaning toward snow Thursday into Friday. I could be wrong though, but 850 temps are still projected at -6c and thicknesses are still showing about 522dm. Could see that overrunning event?
    http://www.cascadeaccess.com/~mnelsen/Models/avn00zsfc.html
    Not sure about our wind event, its at 988 starting to make its northerly turn toward northern vancouver island though. Looks to be starting to strengthen though now.
    http://www.atmos.washington.edu/~ovens/loops/wxloop.cgi?sat_sfc_full+12
    Any thoughts on Thursday/Friday?

  14. Heatblizzard silverton Or near the gardens says:

    Looks more like the eye of Sauron to me the way it is described link please?. Possible final report for the night. temp 43. Elec,Baro 29.47 rising trend. The moon is out and there is a ring around it kinda errie with it out and almost dead calm.
    (puts Koins forcast in a shelf in the back of blog room with a mountainous pile of back warnings/ peoples old forcasts from 1880s. Sticks nose up in air. Ah who needs to know. It most likely won’t happen and the gale will squeeze itself in if that even happens. At least we will be getting the rain hose turned on. Remebers how last storm turned into a surprise flood instead of wind.
    Besides it’s too cold for a south wind event/storm all visual evidence points against it in my opinion tell me if I am wrong.
    Good night y’all don’t let them bed bugs bite. sprays blogroom leaves blog room. Gets in car and drives home.

  15. J.R. says:

    so what time should we see the wind at its peak?

  16. Boydo3 says:

    Whoa, take a look at the 16km water vapor, the dry slot behind the next storm looks like some kind of evil eye! Voldemort!! A piece of his soul? Scary!

  17. Tyler in NW Vancouver (Hazel Dell) says:

    A much warmer night than the last several. 46 right now with cloudy skies. There was a little bit more rain up in Longview today. Looks warm Christmas Eve, then chilly the day after Christmas…

  18. yevgeniy/beaverton/hillsboro says:

    alright weather channel says this for beaverton:
    Rain and wind. High around 45F. Winds SSW at 25 to 35 mph. Rainfall around a half an inch. Winds could occasionally gust over 50 mph.
    Wednesday night windy with periods of rain. Low 38F. Winds SW at 15 to 25 mph. Chance of rain 80%. Rainfall near a half an inch.
    with all the rain we had maybe we can guess what is the next step

  19. Tornado Aly (Vancouver) says:

    Wow, look at la la land, the 26th through Jan 3rd on Meteostar. Check out the winds!!!
    http://wxweb.meteostar.com/sample/sample.shtml?text=KPDX

  20. Lonewolf >Vancouver,WA says:

    Thanks Mark. I will look up Pete Brothers and see what their offerings are. I’m on a tight budget for this hobby, so I want something that will get me by for a year or so with the ability to start recording my data. Then, when my wife is convinced that this hobby will be beneficial for us, I’ll upgrade! I have yet to figure out how to convince her of that…
    🙂

  21. Heatblizzard silverton Or near the gardens says:

    It’s 45 degrees here it dropped 1 degree more. Those winds are normal in the Rockies and there is usually snow accompanied with them which then is called a blizzard sometimes there are whiteouts. Wowwwwwwwwwwwwwww!!!!!!! being a smart alex. Yevengiy you won’t get to laugh at us unfortunatly for you.

  22. Mark Nelsen says:

    I’ve always been real happy with Peet Bros. weather stations. I’ve been using them since the mid 1990’s and in the last 4 years or so have VWS software for using it on the web.
    A sample is here:
    http://www.cascadeaccess.com/~mnelsen/wx.htm
    Kind of disturbing that you know when my heat kicks on in the morning (inside temp), but I like the graphs.

  23. yevgeniy/beaverton/hillsboro says:

    you know what would be interesting, if those winds did strike our area tommorow, then i would be laughing at you guys…

  24. Lonewolf >Vancouver, WA says:

    Thanks for the weather station info, everyone!

  25. Heatblizzard silverton Or near the gardens says:

    Seriousl I can understand 65mph winds on one day for a couple hours but that long give me a break this isn’t Montana or the Rockies. Our climate has to be screwed up if that pans out.

  26. Heatblizzard silverton Or near the gardens says:

    My temp has dropped to 46 now and the Electric Baro is 29.38 and rising. I think the Koin office is drunk or bored I am betting on bored. I don’t blame them either this winter has been slow as Molasses to start and more clouds then sun without much rain bleh. I want the rain rain rain I am sick of the nothing clouds. Ahem. I hope this isn’t going to be like the 1999-2000 Lanina dud. We all know what happend that winter I am sure. Don’t worry I am not making fun of anyones forcasts to hurt them. 65 mph winds I am not taking Koin seriously HA HA HA HA HA HA HAAAAAAA!!!!!! to Koin. Laughing face. Falls backwards on chair. CRASH!

  27. Dr. Rob -Far S.E. Portland- says:

    My thoughts on tonight’s low…
    A few things I see on WV/IR loop that wasn’t a factor with Today’s low.
    1) Cold air feeding into the low
    2) Very deep well maintained and fast moving dry slot
    3) Strong 150kt jet punching into the storm and guiding it very quickly.
    I think these factors may lead to very good intensification soon.
    http://www.atmos.washington.edu/~ovens/loops/wxloop.cgi?wv8km_enhanced+12
    In reading the NWS AFD they seemed concerned with strength, meaning it could be stronger than models indicate. We’ll see how things play out over the next 6-10 hours.

  28. Lonewolf….feel free to email me with any questions on the station I have and what I do with the data. weather at brianfeller dot com (I’m sure you can figure that one out).

  29. offroadjosh(kila-7miles west of kalispell Montana) says:

    my honeywell had prbs at first(bad unit) then i got another opne been great since!!! very accurate
    honeywell TE923

  30. yevgeniy/beaverton/hillsboro says:

    good god i found this on koin weather for hillsboro:
    Issued at 03:42 PM PST
    Tonight… Showers in the evening…Then rain after midnight. Lows 35 to 40. West wind 15 to 20 mph…Shifting to the south 20 to 35 mph with gusts to 65 mph on higher terrain possible late tonight.
    Wednesday… Rain in the morning…Then showers. Highs 40 to 50. South wind 25 to 40 mph…With gusts to 65 mph on higher terrain.
    Wednesday Night… Showers. Snow level 2000 feet lowering to 1500 feet after midnight. Snow accumulation up to 4 inches. Lows 35 to 40. Southwest wind 15 to 25 mph. Gusts to 50 mph in the evening.

  31. Sean Connery says:

    The only station worth getting beyond a regular sensor is the davis pro vantage 2 system. All of the others have crappy functions that will not be what you payed for…

  32. B1900 Pilot Bethany, OR (400') says:

    Lonewolf–
    I have the system. I have mixed feelings about it.
    Pro: It’s accurate (to about .2 degrees), readable, pretty easy to install and put together.
    Con: The software interface is very basic and it’s difficult to graph any data or allow you to post it to the internet. It doesn’t update wind speeds real time, just every two or three minutes.
    For the price, it works in a pinch. If you have the money to go to a more expensive brand, ($200 or more) go for the more expensive version.
    I hope that helps. Let me know if you have more questions.

  33. kyle ---- east vancouver says:

    lol lonewolf that was good.

  34. Lonewolf >Vancouver, WA says:

    So, according to that chart (http://wwwt.emc.ncep.noaa.gov/gmb/pan/t18z_3/PDX_2.gif), that would be approx. 3MM precip. for a 12hr period on Christmas Eve night/Christmas morning?
    How much snow does that equate to?
    Let’s see: dry snow 20/1, 26MM per inch, 20/26 = .769in. per MM, .769x3MM= 2.3in.! That is, if it’s dry snow. If it’s wet, maybe more like .924 in…
    For each day prior to the forecasted precip. subtract .2 inches of accumulated snow. 6 days x .2in. = 1.2 in. I think that puts us upside down in accumulation totals…
    🙂

  35. J.R. on cell (sidekick LX) at work says:

    Starting to get windy this 1 last leaf on this tree just blew off omfg lol

  36. Andrew---Ellensburg, Wa and Portrland, Or says:

    Just talked to my friend up in ellensburg (since i am currently in Portland). Looks like they picked up several inches of new snow overnight into this morning with another 3-5 inches expected late this afternoon into tonight.

  37. jacob BPA says:

    Click to access NCEPMAF.pdf


    Read to learn more about these charts Click above

  38. Ben says:

    Yeah, a white Christmas up at Govi Camp.

  39. and now it’s gusty with the showers…

  40. jacob BPA says:

    Its the FAb 5 Windicator
    LOL
    Snow Levels Get low After Wed day
    And will have to keep a close Eye on this.
    Will know more tonight
    Wind, Wed should see better Wind 30-40 mph gust Possible in Pdx Area As For Xmas Things Chance of A white One Maybe
    More to come

  41. Marc ( NE Orchards, WA) says:

    It was warm today!

  42. offroadjosh(kila-7miles west of kalispell Montana) says:

    R.I.P Matt!!!!

  43. offroadjosh(kila-7miles west of kalispell Montana) says:

    Hey just a reminder to y’all… be safe out sledding. and don’t let someone tow ya behind a vehical even in an open area. i just lost a friend to that over here. friends dad slid the sled around at 40mph and my friend fell off hitting his head. killing him instantly:( so please be safe!

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