Is There Going to Be a Wind Storm Thursday? Maybe


The next 3 days we have a very active weather pattern with warm & windy systems moving across the Pacific Northwest.  The source region of the air is well to our south/southwest, so snow levels will be around 7-8,000 feet the next two days.  Forget about ski areas making a big opening this weekend.  This is our forecast for the next 7 days up on Mt. Hood. MarkSnow_MtHoodFcst_2013  Not good.  HOPEFULLY we don’t get much ridging next week and can squeeze out a couple of feet of snow at some point to at least get some sort of skiing open for Christmas Break.  The ECMWF model is not very hopeful, the GFS a bit wetter.  We’ll see.

Let’s talk about the stormier weather the next few days.  We have one system moving onshore later tonight.  That should give a burst of southerly wind along the coastline later tonight through early tomorrow morning.  A good surge of rain too.

A second system moves in on Wednesday.  This one is stronger with wind gusts along the coastline more likely into the 70 mph range…this is where ears perk up along the coast.  Gusts to 70 or higher are what start causing damage.  We’ll get some southerly wind in the valley again, but neither or these two systems are right for giving strong wind inland.  The pressure gradient is a bit too “southeasterly”.  For strong wind in the valley, you want the pressure isobars oriented as close to east-west as possible.  It doesn’t do that with these next two systems.  More rain arrives Wednesday afternoon, and I expect a good 2-3″ widespread across the region west of the Cascades by Thursday.  This isn’t enough to cause flooding, but definitely enough to remind us we are in the middle of the wet season.

By the way, the warm airmass and southerly wind means very warm temps…I think late tonight or before noon tomorrow the western valleys of Oregon/SW Washington may see temps right around 60 degrees.

Now on the really interesting stuff…Thursday.

Several models (notably the GFS) are showing a near-perfect windstorm setup for the Willamette Valley on that day.  The GFS shows (for the past couple of runs) a surface low pressure center deepening rapidly west of Eureka/Brookings and then tracking north very quickly along the coast.  This is how the latest run looks at 10am Thursday:


notice the surface low is just north of Astoria.  What you don’t see here is the incredibly fast movement…about 350 miles from off Brookings to far NW Washington in just 10 hours or so.  That fast movement means pressures fall and rise very quickly as it passes by.  This speed can really add to the effect of the south wind rushing in behind the low as it moves north.  This track is similar to the OMSI Weather Meeting Storm on October 25th.  I just made up that name…it’s not official.

Our RPM model and the UW-WRF model also show a strong low tracking north too.  Not a surprise since they are based on the GFS model.    Check out the crazy WRF-GFS with major windstorm material for our area.  It produces gusts 70mph in the north Willamette Valley.


So why not forecast a big windstorm?  Two reasons.  One is the upper-level pattern.  I don’t like the “splitty” look to the large upper-level trough to the west and it seems odd that models are deepening a low pressure center so rapidly in that general environment.  The other reason?  Check out the 00z GEM, 12z ECMWF, and 00z NAM…two of those are saying  “what storm?  I can’t even find a low pressure center!”




We’ll get a new ECMWF model for this period just after 10pm.  If it still says CAN’T FIND A LOW PRESSURE center I’ll sleep just fine tonight.  If suddenly it’s showing a deepening low coming up the coastline…things are going to get exciting real quick.

10:15pm update…ECMWF just came in.


It now has a closed low tracking quickly north like the other models.  This says the central pressure is just under 988 mb, but the WeatherBell version is down around 980mb.  There are two key differences…the low is filling after it gets near the central Oregon Coast, and the path takes it inland around Astoria.  Then northeast to near Seattle.  This track (with a similar strength low) would give our area stronger wind than a track offshore.  On to the next run of models to see if they stay with the idea.

Chief Meteorologist Mark Nelsen

52 Responses to Is There Going to Be a Wind Storm Thursday? Maybe

  1. The KING of Weather Spreadsheets says:

    Hi Mark

    I guess since there has been so little agreement all we can do basically is be prepared and stocked up for whatever may happen out there.

    Interesting that the ECMWF finally jumped on board last night with some indication of interesting weather possibly happening.

    The NAM is usually the best at modelling the weather in the short term over our terrain here in the northwest and yes in the short term I do prefer even that over the sometimes really awful GFS.

    I haven’t looked at the NAM yet today but will through the UW portal because I always feel better and safer looking at the models the UW has on their website than the NCEP website which seems to vague for me a lot of the time.

    It will be interesting to look at what the Canadian GEM says and it appears the Brit model (UK Met) according to Cliff Mass is hinting at something brewing too.

    For now I will expect more rain but if a 980 or lower millibar low scrapes right up along the coast at us I will surely would not be surprised to see the trees really leaning over from south to north in my neighborhood. 🙂

  2. PurpleHaze says:

    I’m happy as long as we have at least a marginal snow event in January of 1-2 inches on the valley floor!

    When was the last January snow event for the valley floor of at least 1 inch?

  3. W7ENK says:

    Ooooh she’s a beauty, ain’t she?!?

  4. After viewing 12z runs(except for ECMWF) here are my thoughts….
    All models have converged on the idea of a closed low rapidly developing somewhere off the northern California coast. We definitely see improved agreement on the placement, trajectory, and track of the low. I think this also suggests that things may not be as splitty inside 130 W as previously thought. It then heads northeast deepening peaking somewhere off of Newport to North Bend, then weakening as it continues to move northward. Some models have this degrading process slower than others, and some peak the low too soon. Those specifics are important and have yet to be resolved. The WRF would obviously still be the biggest threat for widespread damaging winds. I think overall momentum has increased towards seeing at least a Wind Event with gusts to 40-50mph with the potential for a much stronger situation with widespread gusts 60mph+. We’re getting closer to seeing the final solution on the models and whether or not we just see a breezy-gusty event, or an all-out Willamette Valley Wind Storm. 00z runs tonight will iron out those details even further.

  5. Tyler Mode says:

    Finally warming up here. 54

  6. Tyler Mode says:

    12z shows a similar low, if not a little more baggy, and it is further south, which would bring stronger winds south of Portland.

  7. Sapo says:

    mm5-NAM definitely doesn’t look good for a windstorm on Thursday…Shows some strong gusts a little bit south of Portland at about 1pm Thursday, but that’s about it.

  8. Marc (East Vancouver) says:

    48 degrees at mine. Temp has not budged at all in the last 12 hours.

  9. Tyler Mode says:

    46 at my house. Still cool (relatively). 60 just a few miles east.

  10. Neil says:

    New to area. Just found ur blog. Good info. Thanx!!!

  11. I don’t like the South wind. It makes my driveway a mess because that’s where the trees are located. The east winds are fine.

    • Marc (East Vancouver) says:


    • Mike in the woods says:

      It’s good though because it helps weed out and thin out the weak branches gradually, not all at once. This also should allow you to spot a weak tree before the big wind ever hits. If the ground moves at the base of a tree you had better take it down.

  12. Larry says:

    At least this time we don’t have tons of oak leaves to deal with. Just hosed out the wishtrain too.

  13. ChiefWright (Marquam) says:

    Opened the door this mid December morning to read the rain guage– and it was warmer outside than in! Granted, we keep a cool house in the evening (60 degF), but it’s bloody 65 degF out there this morning! This is just wrong, all wrong.

    But I’ve got the windows open for to air the house out, anyway. Take advantage of what crazyness there is to prepare for the appararant crazyness to come…

  14. 6z NAM
    Deep low, but peaks off the northern California coast, then weakens very quickly as it moves northeast. Breezy to gusty conditions, but not a wind storm.

    6z GFS fairly deep low, but weakens north of Newport. Breezy to gusty winds, but not a wind storm.

    Onto 12z run. NAM in 3 hours 45 minutes. GFS in 5 hours 27 minutes. WRF in 5 hours 40 minutes. ECMWF in 8 hours

  15. schmit44 says:

    12/8/2014 Oregon (All) Temperature Summary

    High:67 at EW4053 Myrtle Po( 417 ft)
    Low: 60 at Gold Beach (US 1(60 ft)

    High:33 at MIDDLE MTN(2544 ft) & GREENPOINT(3200 ft) & BARNHT(894 ft)
    Low: 22 at CROW FLAT (5172 ft )

    Largest Diurnal Change: 31 degrees
    GRIZZLY NEAR CUL (57/26 ) (3635 ft )

    Heaviest Rainfall:
    0.38″ at QUAIL PRAIRIE LO(3183ft)
    0.34″ at EW1765 Mount Hoo(1542ft)
    0.25″ at EW4856 Brookings(1365ft)

  16. paulbeugene says:

    Just saw the 50-member Euro ensembles. Much more support for an intense low to track rapidly N along the Oregon Coast. Things may be coming together for the biggest windstorm thus far in this millennium for NW Oregon urban areas.
    I imagine NWS will issue SPS tomorrow morning and a perhaps a high wind watch by Wednesday .
    I imagine the pummeling the Doug firs took from the east winds followed by significant rains is a set up for trees coming down.

    • alohabb says:

      Wow, you don’t jump on board to quickly, but by what your saying shows we might really be in for it…Gonna be a busy blog for a day or two

  17. Jake-(Gresham) says:

    Call me crazy but California’s drought/flooding almost mimics a sub-drought and sub-monsoon seasonal pattern. I don’t know why we don’t just call it that – it’s pretty much what they got down there year after year.

    • Jake-(Gresham) says:

      sub-dry season

    • David B. says:

      Because a monsoon denotes a wet season in the warmer months of the year, and California’s (and the whole contiguous US Pacific Coast’s) wet season happens in the cooler months.

  18. Aleta- West Gresham says:

    We’ll see if it happens but with the luck I’ve been having with losing electricity I’d better get a battery back up for my poor computer.

  19. ChiefWright (Marquam) says:

    These model runs are about as volatile as ether on a hot plate, but better safe than sorry, especially with all that rain. I’m checking my generator first thing tomorrow morning.

  20. ECMWF still not a big wind storm, but much stronger than previous runs, and most importantly shows a closed surface low which makes one think is it jumping on board with the GFS/WRF….

  21. W7ENK says:

    I’ll believe it when I see it…

  22. Onto 6z …..
    6z NAM in 1 hour 30 minutes
    6z GFS in 3 hours 15 minutes

    Then 12z…..
    12z NAM in 7 hours 30 minutes
    12z GFS in 9 hours 15 minutes
    12z GFS in 9 hours 35 minutes
    12z GEM in 9 hours 35 minutes
    12z ECMWF in 12 hours

  23. Marc (East Vancouver) says:

    Mark, yep. Should be a fun next few days.

  24. Yep, Mark. Which model blinks first? GFS towards the weaker GEM/NAM/ECMWF? or does the ECMWF join in on the fun. It’s just hard to imagine with the split jet inside 130 W….

  25. Jake-(Gresham) says:

    I have to say because the EURO says nope I’m going to have to say I’m going to be shocked if this comes to fruitation if it shows up randomly tonight. Really shocked, especially with the split flow as Mark stated.

    ~Merry Christmas everyone!

  26. Tyler Mode says:

    Once again…models having a rough time even in the short term.

    I wonder what the GFS is seeing that the others aren’t or vice versa?

    • sds says:


      I don’t know what the GFS is seeing, but I saw that you’ve found my old stomping grounds in Mt. Margret back country to your liking. Before the Mt. blew I spent many a weekend off trail exploring the hidden lakes via game trails. Have you gotten into Island lake yet? The fishing used to be unreal for those who knew.

    • Tyler Mode says:

      Haven’t yet, but MMBC is now one of my favorite areas of the NW…and I plan on returning every year!

  27. schmit44 says:

    I guess I will hold off on cleaning mom and dads roof until Friday with the potential mess coming Thurs.

%d bloggers like this: