A Few Maps This Morning

11am Tuesday…

Morning model runs of the GFS and GEM both still show a very strong low pressure center racing up the coastline Thursday morning.   Check out the two GFS runs for 10am Thursday.  These are maps from WeatherBell.  The first is the “regular” model, the 2nd is the upgraded version which is still in testing mode and being run in parallel with the operational run for another month.

gfs

upgrade version:

gfd_upgrade

They are both similar, although the upgrade version is significantly deeper with the low and just slightly farther offshore.  Note the wind at 850mb (around 4-5,000′).  Near 100 mph southerly wind over our heads!  Then check out the GEM (Canadian global model):

cmc_mslp_uv10m_nw_9

A deeper low snuggled right up against Tillamook at the same time.  Wow…that’s a huge storm.  Now check out the morning ECMWF run.  First map from the same time (10am) as those above:

ecm10am

2nd map from 4pm.

ecm_4p

…much weaker and “baggier” with the low pressure center.  This would just be a windy afternoon with gusts in the 30-45 mph range.  So I’m not sold on a big windstorm Thursday morning until I see that Euro come around a bit more.

The UW’s WRF-GFS model, based on the GFS, produces a big windstorm for us.  Pressure jumps are strong behind the low…10 millibars in 3 hours at Eugene between 8-11am and a pressure gradient of 16 millibars Eugene-Olympia.  Combine that with a fast-moving low and the strong overhead wind; you’ve got gusts 50+ at least in the valley and Portland.

More after the evening runs come out.  Hopefully they will pull together a bit or “cancel” a windstorm.

Chief Meteorologist Mark Nelsen

49 Responses to A Few Maps This Morning

  1. My only concern if we want a big wind storm is the low wrapping up undergoing deep cyclogenesis too soon because all of the ingredients are there for a potent storm…. We’ll probably know by 12z tomorrow…..

  2. Marc (East Vancouver) says:

    I will say this.. Mark is great. But, if he waits until tomorrow for better model agreement, I’ll be a tiny bit disappointed. The train leaves the station tonight, not 12 hours before the “event”! Go Mark!

    • Boydo3 N. Albany elev. just under 500' says:

      The problem is the train is on it’s own track and schedule. Trying to figure those out is the key. Better forecasts come with more data which, in this kind of thing, will have to wait just a bit longer.

  3. Long Post…

    8:30 PM Update Analysis

    Viewing IR/WV loop I foresee an absolute monster is about to unfold one that models don’t yet have a handle on the explosive cyclogenesis potential this low will have. I already am seeing strong vorticity and circulation near 37 N, 159 W. That is our storm for Thursday. Very strong jet over 200mph, some subtropical moisture, and a ton of cold air has poured well south thanks to a deeply suppressed jet. The ingredients are all there for the Pacific Northwest to have an absolute beast on our hands. If anything, and this has happened more times than I can count, the low could enter its rapid deepening stage too soon and curl northward just a bit further offshore. That’s a possibility. I just really like what I see with the initial stages of development. This is supposed to form into a wave of low pressure around 4-7 AM near 150 W, and now we can watch all of this develop in real-time. I think the question is how much jet support will ride up along the Oregon Coast inside 130-128 W. If we see a 120mph+ left exit jet and no splitting, western Oregon /Washington may not escape a damaging event. Fun stuff ahead possibly. If splitting is apparent then a wind storm is unlikely.
    WV Loop http://www.atmos.washington.edu/~ovens/loops/wxloop.cgi?wv_enhanced+12
    IR Loop http://www.atmos.washington.edu/~ovens/wxloop.cgi?ir_enhanced+12

    Now tonight’s models…
    Check out the left exit jet support on 00z GFS! 140-160mph! No way that low weakens as quick as models are showing, plus with the fast forward motion will negate the impacts of it degrading/filling. No splitting apparent either. http://www.tropicaltidbits.com/analysis/models/gfs/2014121000/gfs_uv250_nwus_8.png

    Keep in mind models will still waffle a bit on overall strength, compactness, weakening phase, and gradient couplet, but look at the key factors: Placement, Trajectory, Track, and Jet support. These are all looking good. We get to watch all of this for 36 – 48 hours in real time develop in front of our eyes and let’s just see what happens, or doesn’t.

  4. Marc (East Vancouver) says:

    This is why Mark makes the big bucks. Time to make a big time forecast!

  5. W7ENK says:

    lol

    Well that just ain’t gonna work…

  6. Mike P says:

    18z GFS arctic outbreak beginning Christmas Day. It’s a lock.

  7. gidrons says:

    It’s been awhile since we had a big bombing windstorm. Historically all computer models have a hard time with cyclogenesis. I know its improved, but the GFS has been notoriously bad in the past. I used to think the GFS model was developed from flushing turds down the toilet. I’m not getting on the train until the ECMWF is on board.

  8. Seattle NWS AFD sheds some light on things

    POTENTIALLY A STRONG OR EVEN MAJOR WINDSTORM AFFECTING PARTS OR ALL OF WESTERN WASHINGTON WILL ARRIVE THURSDAY. MODELS PRIOR TO TODAY`S 12Z RUNS WERE NOT IN VERY GOOD AGREEMENT ON THE TRACK AND STRENGTH. THIS HAS CHANGED WITH THE 12Z RUNS CONVERGING TOWARD A STRONGER WIND EVENT AFFECTING WRN WA INCLUDING THE GREATER PUGET SOUND REGION AND I-5 CORRIDOR. IN FACT…IF SOME MODELS ARE CORRECT…THIS MAY BE A REGIONAL STORM IMPACTING THE W COAST WITH HIGH WINDS FROM NEAR EUREKA CA NWD THROUGH ALL OF WRN OREGON AND WRN WA. VIRTUALLY ALL THE MODELS AGREE THAT RAPID CYCLOGENESIS WILL TAKE PLACE AS A STRONG WAVE REACHES 130W/40N…THEN MAKES A NWD TURN.

    THE GFS13/40 AND WRF-GFS CONTINUE TO BE THE STRONGEST WITH THIS SYSTEM DRIVING A NEAR 970 MB NWD OFF ASTORIA THURSDAY MORNING…THEN NWD OVER OR JUST W OF PUGET SOUND. THIS WOULD BE A WORSE CASE SCENARIO…LIKELY RESULTING IN DAMAGING WINDS ACROSS THE LOWLANDS. IT IS STILL 36 TO 48 HOURS FROM THE EVENT AND SLIGHT VARIATIONS IN THE TRACK AND DEPTH OF THE LOW WOULD WEAKEN THE WIND THREAT CONSIDERABLY. ALSO…OTHER MODELS ARE WEAKER WITH THE SURFACE LOW. BUT THESE MODELS…THE ECMWF /NAM12…APPEAR TO BE PLAYING CATCH UP WITH THE OTHER MODELS WHICH LENDS MORE CONFIDENCE TO THE GFS /CANADIAN SOLUTION. ALL SOLUTIONS WOULD GIVE SOME WIND TO THE AREA. WILL ISSUE A HIGH WIND WATCH FOR THURSDAY THROUGH THURSDAY EVENING FOR ALL OF WESTERN WASHINGTON. DETAILS CAN BE REFINED AS WE GET CLOSER TO THE EVENT AND ANY WARNINGS POSSIBLY ISSUED. FORECAST SHOULD BE MONITORED CLOSELY AS THIS COULD BE A SIGNIFICANT WIND EVENT FOR THE REGION.

  9. Lights flickering and not even windy yet… Probably not a good sign.

  10. Anyone else find it interesting how Seattle NWS suggests gusts to 65mph when Portland NWS only going with 60mph(and high uncertainty) The low likely peaks somewhere near Astoria-Lincoln City, so the strongest gradient should swing inland right over the Willamette Valley, then weaken slowly up throughout western Washington. To me based on the WRF/GFS/UKMET ECMWF Ensembles this is probably a conservative estimate to only go with 60mph gusts. Still plenty of time to upgrade that though. 00z runs will be very telling tonight!

    Model Countdown

    00z NAM 2 hours 13 minutes
    00z MM5-NAM 2 hours 23 minutes
    00z GFS 4 hours
    00z GEM 4 hours
    00z WRF 4 hours 8 minutes
    00z ECMWF 6 hours 22 minutes

  11. W7ENK says:

    Here we go…

    HIGH WIND WATCH
    NATIONAL WEATHER SERVICE PORTLAND OR
    253 PM PST TUE DEC 9 2014

    http://inws.wrh.noaa.gov/weather/alertinfo/19720514

  12. High Wind Watch issued for all of Seattle-Tacoma metro and Puget Sound. Wednesday Night – Thursday Evening South Winds 30-40mph G 60-65. To me this all but guarantees a High Wind Watch for the Willamette Valley. Every model shows the tightest gradient couplet south of western Washington/Puget Sound areas, which could imply gusts well over 65mph PDX-SLE, maybe EUG. I would have waited personally for 00z runs before I pulled the trigger or not on a High Wind Watch.

  13. WEATHERDAN says:

    4 years ago I had an 80 ft. tall Elm tree go down in a wind storm in my back yard. The Tree hit my covered patio and the back part of my house. It also hit two other houses. The damage to my property was $22,000. My insurance took care of all the damages, and because it was considered an act of God the other property owners insurance took care of theirs. But I don,t want a repeat of that mess. So a big blustery/gusty day with winds up to about 50MPH is okay. But gusts of 70 or 80 MPH means misery for people. Now this isn’t a rap on those who forecast it, but rather on those who want to see a damaging storm. Even a daylong power outage can cost people hundreds of dollars in ruined food. So if I had a choice which I don’t I would be good with winds to maybe 50 or 55. But we shall see what happens. Merry Christmas to all. Peace.

  14. Some more info….
    12z ECMWF Ensembles: Increased support for a deep low, and I see a few members under 970mb hmmm….

    18z GFS 500mb under 546dam threshold, 120-140mph left exit jet support

  15. 18z GFS looks good about 973mb just west of Lincoln City… Since it’s typically a weaker run, and definitely not as reliable….

    We need to see how well the front holds together on Wednesday or if it splits any. To me that would verify whether or not there will be any splitting of the upper level trough/energy in the environment where Thursday’s low develops and tracks northward. Looking at the possible jet support, IF there is no split jet I could see the very real potential for this low to deepen just under 970mb…. Worst/best case scenario there…This is probably the most vital ingredient as to whether or not we see a big windstorm or just breezy conditions.

    Might be fun 00z runs tonight.

  16. 18z NAM
    Deep low around 974mb peaks off the northern California Coast, then weakens and elongated west of North Bend. Not a Wind Storm. 18z though is typically the worst model run with the least data input. 12z/00z are obviously far more accurate and reliable. Onto 00z NAM.

  17. Well, this certainly sucks. The Meteostar website that we primarily use to view Pressure Gradients will no longer be free to use starting January 15th.

    “Attention: On 15 Jan 2015, this web site ( wxweb ) will become a fee-for-service site requiring a password for use. If you wish to continue using wxweb, contact sales@meteostar.com for our usage-based price list and for answers to other questions. Thank you in advance for your patience during this transition. We have appreciated your use of wxweb and your feedback over the years.”
    http://wxweb.meteostar.com/

    We will have to use this site instead:
    http://www.wrh.noaa.gov/zse/sea_gradients.php

  18. Thanks for the update, Mark. This is definitely becoming very interesting….

    Viewing the 12z GFS further 250-300mb shows what you want to see if you want a Wind Storm. If you follow the streamlines this chart clearly shows no split flow off the northern California or southern Oregon Coast and instead we see a consolidated strong southwesterly jet core well over 100kts slamming into SW Oregon. This is why the GFS/WRF has consistently been spitting out deeper and stronger runs. My hunch is the NAM/GEM/UKMET are all trending this way with the ECMWF trailing along slowly. 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.

  19. pdxgeologist says:

    I don’t like the idea of a very strong south wind because of the large tree upwind from my house. Thing sheds big limbs and we’ve had a few near misses. Gonna keep my eye on this one from down here in Panama so I can warn the wife if it looks like it’s going to get outa hand.

    • Jane - Forest Grove says:

      100% agree with you….But, if we are due to have one…I prefer it during the daylight hours. Safer for those of us surrounded by 100′ fir trees. (My neighborhood might make the news this time) 😦

    • W7ENK says:

      Hey, did you feel that earthquake down there the other day?

    • pdxgeologist says:

      Felt the foreshock on Saturday. Sitting in my office trailer at the canal around noon and my geologist partner and I both looked at each other and said “did you feel that” and a few seconds later we felt the “S” wave go through, so we knew it was far off (separation between primary “p” wave and the shear “s” wave is a function of distance as they travel at different velocities). Slept through the Monday quake (3 AM).

  20. pdxgeologist says:

    First?

%d bloggers like this: