Snow In The Hills

8am Wednesday…

Lots of heavy showers moving through this morning.  I woke up to about 1/4″ snow here at 1,000′ and it’s been going back and forth between sticking and then melting in lighter showers.  A friend up the road has 3″ at 1,800′.  We never saw this pattern last winter and rarely saw it the winter before; cold showers streaming inland.  It’s like the good ‘ol days have returned.  At least for now.  Check out the Troutdale radar estimate of snow level this morning…right around 1,500’.  I think it’s a temporary radar installed for a big Columbia River Gorge and Basin wind power research project.

Capture

The same cold/showery pattern continues through Thursday afternoon, then we pretty much dry out through at least the first part of Sunday.  Looks to me that snow levels will be SLIGHTLY lower for Thursday morning, so probably a more widespread dusting down to 1,000.  BUT I DON’T SEE IT LOW ENOUGH TO AFFECT TRAVEL IN THE METRO AREA.  IT’S MAINLY A “CONVERSATIONAL SNOW”.  That means it looks nice with green trees all frosted and you chat with friends about it, but you can still go about your daily lives.

Looks like a dramatic pattern change to splitty/much drier after Christmas Eve.  That may (or may not) be the usual slowdown in weather we see in El Nino years.

The main message for skiers is…get the good powder now because this COULD be the best snow of the season!

I’m still on vacation through Christmas Day, but you know that “relaxing” for me is looking at weather maps, eating, sleeping etc…

Chief Meteorologist Mark Nelsen

161 Responses to Snow In The Hills

  1. Leeateea says:

    To me it sure looks like the moisture is going to be here way earlier than the morning!

  2. JohnD says:

    A few things from my novice perspective:
    IF there was ever a time for the GOLU “model”, this would probably be one of those times!
    E.g. Low dew points–ripe for evaporational cooling!
    My thermometer reads 37.9 here in inner SWPDX at the moment.
    Wonder where Mark is?
    ‘Know he is on vacation but his eventual input will be telling.
    OR maybe his absence speaks for itself!!

  3. Boring Oregon says:

    About how low does humidity have to be for there to be evaporative cooling?

  4. geo says:

    DP’s are 27,29 and 32 at troutdale,PDX, and HIO

  5. WEATHERDAN says:

    38 after a low of 28. Coldest day so far this month. Looks chilly with a couple of borderline snow chances this week. Also a cool but dry New Years Day. Peace.

  6. W7ENK says:

    LOW SNOWFLAKE WATCH
    NATIONAL WEATHER SERVICE PORTLAND OR
    249 PM PST SAT DEC 26 2015

    http://inws.wrh.noaa.gov/weather/alertinfo/27809478

    • Boring Oregon says:

      Oh no, now that the NWS is predicting it It’s not going to happen.

    • 850mb temps are above freezing and there is little or no offshore component and there isn’t a bunch of cold air east of the mountains. This is not going to materialize.

    • And when in the hell is 1″ of snow above 500′ a news worthy event?!

    • chris s says:

      850 temps are below freezing for one thing, not sure where or what you are looking at. Also, the cold pool really isn’t what is driving the chances for this system, that will come with the system on Tuesday. There is a decent chance of some damming effects around the usual spots with this system tonight, like forest grove etc, but ya the chances for people below 500ft otherwise are not really great.

    • My bad meant 925mb temps are above freezing. Also I could give an ‘S about Forest Grove or cold damning locations. The vast majority of the metro is still going to be cold rain.

    • Chris s says:

      Eh, 925 temps are actually not above freezing at the moment. And they are modeled to stay below or right at freezing till tomorrow morning. Again, I realize it’s a long shot for pdx snow, but when isn’t it for you folks in pdx metro area😀

    • Farmer Ted says:

      ryan loonie bury. Have you ever been mellow? Can you ease up a bit during these nice days of Christmas, maybe try and develop a sense of wonder and joy, after all if you can’t do it now, it won’t be any easier during the rest of the year.

  7. I’m cautiously optomistic for snow sometime in the coming week, even today. (overcast and 36F) The long range forecast indicates colder, drier weather for New Year’s day, but that can change. Man, it’s tough to say what’s going to happen! :-}

    • Boydo3 N. Albany says:

      It is tought to say… but….all the models are honing in on a long dry stretch. Good thing we got the mtn snow now or it would start to look alot like last winter, and the year before.

    • If nothing else copious amounts of “fake cold” thanks to a weak sun angle and valley clouds/fog.

  8. 12z WRF 4km Sounding for PDX at 10:00 AM Sunday morning looks similar to previous runs. This is a wet snow sounding, possibly slushy accumulations, if briefly. I assume anything would be brief.

    4:00 AM Tuesday is also a bit interesting, but a touch too warm.

    A few things different on this run.
    7:00 AM Thursday. Yes, the PDX-DLS is very strong here(It actually strengthens further Thursday night!), Wind Advisories for sure east of I-205(Maybe a High Wind Warning if the inversion is a bit stronger), but also note the very deep low level cold air flooding into the Columbia Basin/eastern Washington. We’re talking 925mb temps of -9c to as cold as -15c. This is a very significant cold pool and it’s what I mentioned I felt we could see an impressive one develop.

    • Benjamin (West Salem) says:

      December 29th 2009 anyone??? lol. I know this is different, but in some ways my wish casting self wants to believe that this could be very similar….

    • chris s says:

      Dec 29th of 09′ would be ok, as long as we dont follow it up with a January 2010…. an avg wet torchfest of a month….!!! Didn’t even have one low of Freezing here in Salem…. but plentiful upper 50’s to be had… barf!!!! 🙂

    • Benjamin (West Salem) says:

      I agree Chris. What a boring month that was. Please no. I’m fine with a week or so of fake cold/inversion (it happens ever year just about), but I’m rooting for some big time action this January. Last time we saw a good snowstorm in January was 2004. It’s been far to long. Yes, we’ve all had snow in January since then, but nothing widespread, heavy and long lasting. Only quick hitting shots.

  9. Washougal 1100ft says:

    Is that moisture on the radar coming this way?? Surprise surprise!

  10. Washougal 1100ft says:

    I think your right Rob anytime we get a cold pool east side and east wind blowing anything is possible on the west side and makes chances of frozen precipe a little better only time will tell?

    • Pendleton is going to get to 36 today. There is no cold pool east of the mountains.

    • Cold pool is quite strong from roughly Hermiston northward. It will build and expand further. The main area we watch for is the Columbia Basin in Washington anyways the source of our east wind.

    • Farmer Ted says:

      Rob thanks for helping the novice weather people on the blog that just seem to spout off without any particular understanding of the many various nuances of our NW weather.

  11. JohnD says:

    Getting sooooooooo pumped!!!

  12. Washougal 1100ft says:

    Sure looks like a lot of moisture out there in the Pacific sure be nice to get some! Good stuff Rob east wind starting . I think we might be in for a surprise this week!

  13. Wow. Yakima is down to 3 degrees now. Snowcover is awesome. This cold pool has a chance to get real strong in my estimation. Ephrata-Wenatchee-Moses Lake-Pasco-Pendleton could turn VERY cold overnight into Sunday AM. That’s great for us since it will be funneling very cold east wind into PDX.

  14. sw says:

    It kind of looks like this winter will be sort of a bust if you like winter conditions, especially according to accuweather (which, I know, isn’t super accurate). Knowing that winter “could” be over by the end of December doesn’t make winter nearly as fun a it used to be. But who knows, anything can happen, I guess.

  15. Tyler Mode in Battle Ground says:

    33.4, sadly my second coldest reading of the month…

  16. Tyler Mode in Battle Ground says:

    Today marks 20 years since I began taking weather observations! My dad and family helps with that station now since I’ve moved out.

    Since I’ve bought my own home in BG, it’s been 5 years.

  17. I have somewhat encouraging and exciting news to bring you. It’s kind of like Santa’s big sack of toys, but not really…. I’m only posting the goodies.

    AREA FORECAST DISCUSSION
    NATIONAL WEATHER SERVICE PORTLAND OR
    317 AM PST SAT DEC 26 2015

    THE NEXT SYSTEM IS POISED OFFSHORE ON THE INFRARED SATELLITE IMAGERY. WE SHOULD SEE SOME HIGHER CLOUDS SPREAD IN TODAY. THE MAIN FRONT COMES ONSHORE SUNDAY MORNING AND THROUGH THE AREA SUNDAY AFTERNOON. HOWEVER THE MODELS DO SHOW AN AREA OF PREFRONTAL SHOWERS THAT DEVELOP INLAND TONIGHT AND HAVE ADDED SOME LOW POPS FOR THAT.

    QPF WITH THIS FRONT IS MODEST…AND EXPECT SNOW AMOUNTS IN THE CASCADES AND THE COASTAL MOUNTAINS AND CASCADE FOOTHILLS WILL GENERALLY STAY BELOW ADVISORY THRESHOLDS. HOWEVER…WITH ANOTHER COLD NIGHT TONIGHT…THE INLAND VALLEYS WILL START OUT QUITE COLD SUNDAY MORNING…SO THERE COULD BE SOME SNOW IN THE MORNING AND EARLY AFTERNOON TO RATHER LOW ELEVATIONS ESPECIALLY NORTH OF SALEM. INCREASING EAST WINDS THROUGH THE GORGE WILL CONTRIBUTE TO THE LOWER SNOW LEVELS AS WELL… INCLUDING IN THE GORGE AND THE UPPER HOOD RIVER VALLEY. ADVISORY THRESHOLD AMOUNTS IN THE NORTH VALLEY AREAS AND IN THE GORGE ARE ONLY AN INCH…SO WILL NEED TO MONITOR HOW THAT DEVELOPS.

    THE UPPER TROUGH COMES ONSHORE SUNDAY NIGHT AND MONDAY WITH SOME SHOWERS CONTINUING…THOUGH NOT A LOT OF QPF. THAT MAY BE ENOUGH TO MIX UP THE CHANCE OF ANY LOW ELEVATION SNOW IN THE NORTH VALLEY AREAS BUT PROBABLY NOT IN THE GORGE. TOLLESON

    .LONG TERM…MONDAY NIGHT THROUGH FRIDAY…ANOTHER SYSTEM IS FORECAST TO DROP IN FROM THE NORTHWEST EITHER TUESDAY OR TUESDAY NIGHT. THE ECMWF AND GEM MODELS ARE FASTEST…THE GFS MODEL IS SLOWEST. THIS TRAJECTORY AND THE BIT OF EASTERLY PREFRONTAL WIND SUGGESTS **SNOW LEVELS WILL AGAIN BE LOW ESPECIALLY IN THE NORTH AND IN THE GORGE. THE PRECIPITATION EASES WEDNESDAY ESPECIALLY ON THE ECMWF AND GEM MODELS…PERHAPS NOT UNTIL WEDNESDAY NIGHT ON THE GFS. HAVE USED A BLEND FOR NOW FOR TIMING OF BOTH THE ONSET AND THE ENDING OF THE PRECIPITATION. AFTER THAT…THE MODELS ARE INSISTENT THAT A STRONG UPPER RIDGE WILL BUILD INTO THE AREA BY THURSDAY… RESULTING IN DRY COOL OFFSHORE FLOW THROUGH NEXT WEEKEND…THOUGH FOG IS POSSIBLE AWAY FROM THE GORGE IN THE SOUTH VALLEY AND NORTH OF KELSO. TOLLESON

    • This to me seems very possible. It’s kind of a classic overrunning/transition event scenario. We have colder air now settling into the Columbia Basin with temps as of 4 AM in the upper teens to mid 20’s from roughly Hermiston northward. It’s even colder further north. With high pressure sliding inland the cold pool is developing. Lots of stratus/fog is an indicator of this also. PDX-DLS is now switching offshore and east winds will develop later this morning. That will pull the colder/drier air westward through the Gorge. My hunch is like usual models are trying to weaken offshore gradients too quickly late Sunday into Monday. We’ll need things to come together just right(huge surprise), but this definitely isn’t impossible especially late December where it doesn’t take a whole lot to give PDX snow/wintry weather.

      The 00z WRF 4km sounding was really close to a snow profile, if even briefly. 00z runs tonight will pinpoint things better. The other thing to watch for late this week towards New Years is the strong east wind. WRF suggests east wind increases today peaking Sunday morning-afternoon, then it redevelops this Tuesday and peaks Thursday night – next Saturday maybe longer. A very strong PDX-DLS gradient is shown. With the building inversion/warming 850mb temps and a 1040+mb high over the Columbia Basin this screams east wind storm, possibly damaging east of I-205. This also looks like quite a prolonged period of chilly/cold east winds. I can’t tell you how many times we’ve seen this in past Winters and that models do not handle these patterns well or play “catch up” to things as time progresses. I have high confidence this will play out too.

    • 6z GFS Ensembles
      Trending a bit colder through New Years eve. Mean temp dips to -5c and note although precip looks rather meager, when it does occur 850s are -0c or colder. This suggests the east wind will pull enough cold air westward keeping the cold layer just thick enough over PDX for the potential of some kind of Wintry weather Sunday until roughly New Years Eve. Obviously a few wild cards and uncertainties such as moisture, 925mb temps in real-time, and surface flow as crucial. Seems promising to me nonetheless. You can also see the mean temp on New Years Day, Friday rising up towards +8c with a several members suggesting up to +10c. This gives more support for the coming big east winds(in my opinion) If we see 850s at +10c or > it could be crazy. Plenty of time to monitor these things.

  18. schmit44 says:

    12/25/2015 Oregon (All) Temperature Summary

    Warmest:
    High:52 at Gold Beach (US 1( 60 ft)
    Low: 38 at Port Orford(0 ft) & OCNSID Oceanside(22 ft) & Troutdale(120 ft) & ROCKWY Rockaway(450 ft)

    Coldest:
    High:12 at HOWARD Mt Howard(8150 ft)
    Low: -7 at CRAZYMAN FLAT (6180 ft ) & FOSTER FLAT (5000 ft ) & HEREFORD (3599 ft )

    Largest Diurnal Change: 35 degrees
    Agency Lake (37/2 ) (4150 ft )
    Sand Creek (US 9 (29/-6) (4524 ft)

    Heaviest Rainfall:
    1.50″ at BILLIE CREEK DIV(5280ft)
    1.50″ at BIGELOW CAMP(5130ft)
    0.80″ at SALT CREEK FALLS(4220ft)
    0.71″ at QUAIL PRAIRIE LO(3183ft)
    0.66″ at FLYNN PRAIRIE(1543ft)
    0.57″ at FIELDS(3373ft)
    0.54″ at CEDAR(2220ft)
    0.53″ at CANNIBAL MOUNTAI(1939ft)

  19. Meanwhile, most of New Mexico has some sort of winter storm or blizzard warning.

  20. Paul D says:

    Guess I’ll have to shake my daughters snow globe if I want to see any white flakes.

  21. Total Christmas snowfall overnight here: 0.000″. As expected, given how the forecast was trending drier and drier the last 24 hours. From the highway cameras it like you had to go almost to North Bend (WA) to see as much as a light dusting — and 36 hours ago the models were saying 1 to 3 inches there.

    Ah, well. the absence of lowland snow has allowed me to make a last-minute decision to drive to Portland to visit friends today.

  22. Whoops sorry. It’s early and sometimes we need an ‘Edit’ button on posts. My earlier post should have read…

    Interestingly models trending a bit colder this weekend. 6z GFS Ensembles down to -4c mean temp for PDX. Moisture is the wild card. Also noticed 00z ECMWF seems to keep a deep cold pool east side with very strong 1040mb+ high pressure over the Columbia Basin/eastern Washington. Over the next 7 days I wouldn’t rule out the shot at 1-2 transition events PDX/east slopes Coast Range/Gorge eastward as well as an east wind storm.

    • Washougal 1100ft says:

      Merry Christmas to all! As always good stuff Rob thanks for posting . let’s all hope the 6z gfs is heading in the right direction! Cheers!

  23. atmosphericwrath says:

    I want to wish everyone a Merry, blessed Christmas, and safe travels on this holiday weekend.

    I also want to wishcast a Snowy Christmas to all or even a dusting. Okay, how about just Snow in the air? Yeah.

  24. Lance says:

    Is that wishcasting moderation… I’ll get a new login. Don’t fret I know my way around ip and mac stuff….

  25. schmit44 says:

    12/24/2015 Oregon (All) Temperature Summary

    Warmest:
    High:48 at DW4535 Cannon Be( 23 ft) & LINCON Lincoln C(187 ft) & OCNSID Oceanside(22 ft)
    Low: 40 at Bullards Bridge(23 ft) & Port Orford(0 ft)

    Coldest:
    High:14 at HOWARD Mt Howard(8150 ft)
    Low: -2 at MASON DAM & PHIL (3899 ft ) & CRANE PRAIRIE (5500 ft )

    Largest Diurnal Change: 34 degrees
    CW9027 Ukiah (37/3 ) (3415 ft )
    DANNER (34/0) (4225 ft)

    Heaviest Rainfall:
    1.70″ at NORTH FORK(3060ft)
    1.50″ at BEAR GRASS(4720ft)
    1.50″ at ANNIE SPRINGS(6010ft)
    1.50″ at DALY LAKE(3690ft)
    1.39″ at Sexton Summit(3842ft)
    1.21″ at AGNESS2(247ft)
    1.10″ at SALT CREEK FALLS(4220ft)
    1.10″ at HOLLAND MEADOWS(4930ft)
    1.04″ at PACCTY Pacific C(253ft)
    0.99″ at FLYNN PRAIRIE(1543ft)
    0.97″ at HEBOWX Mt. Hebo(3160ft)
    0.97″ at ILLINOIS VALLEY(1389ft)

  26. Tyler Mode in Battle Ground says:

    Nearly 15″ of rain in the last 24 days…finally gets cold enough for snow and the moisture is gone.

    That’s the NW for you.

  27. muxpux (Longview) says:

    A foggy 34 degrees up here. Could get a bit icy later as the roads are still mostly wet.

  28. sds says:

    This is for W7 and Lance

    Just like real estate–it’s location, location,location. I live 20 air miles N of PDX–6 miles up the Lewis R. out of Woodland at 250 ft. MSL and we had a winter wonderland this AM with 1.5 in. of snow–still on the roofs and ground. Friends above me at 800 ft. MSL had 3.5 in. and those at 1200 ft. MSL had close to 8 in..

    • Diana F. says:

      ….So you’re telling me there’s a chance?
      ….Or are you inviting all of us snowaholics to crash your pad and watch the snow? : )

    • sds says:

      Diana

      The roof is still white, but it is melting. About 34 outside and 80 inside {the wife likes her wood stove}. If I was a betting man, I wouldn’,t bet on snow–I think we are done in the lowlands for this cycle. The hilltops and trees across the Lewis R. valley are still all white, so the freezeing level stayed around 1600-1800 ft. yesterday and there’s lots of snow for play! A merry Christmas to all.

  29. Farmer Ted says:

    May all the bloggers get their wishcasting stockings filled this season and through the New Year!

    As WEATHERDAN says: PEACE!

  30. High Desert Mat says:

    Mark, how come you have a ? after the dates of 12/1-12/2 for the zr totals at the bottom of your homepage for this winter? I mean, either you did or you didnt have zr. Merry Christmas 🎄 everyone.

%d bloggers like this: