Strongest Gorge Wind This Season On The Way

November 21, 2013

East wind is finally really starting to ramp up now in the Columbia River Gorge.  It’s been relatively light the past day or so.  But now temperatures are starting to warm up overhead, while the cold pool east of the Cascades at the lower elevations isn’t going anywhere through early next week.  Thus a classic setup for a strong “gap” wind event.  That means air moves through a gap in topography.  In this case the Columbia River Gorge.

The highlights:

  • East wind is here until further notice at the west end of the Gorge, at least through early next week.
  • Strongest wind the next 5 days will probably be late tomorrow through midday Sunday
  • Peak gusts 35-45 mph in the eastern Portland/Vancouver metro area east of I-205
  • Close to the mouth of the Gorge gusts to 50 mph are likely (Camas, Troutdale, N. Gresham)
  • Gusts 70-75 mph in Corbett and Cape Horn areas.
  • Saturday looks like an excellent day to experience the high winds at Vista House!  Although Friday and Sunday will work too.
  • Gusts at the sensor there should be in the 75-85 mph range.  That means 95+ on the “Keely Chalmers Memorial Railing”

–  00z WRF-GFS is slightly stronger showing a DLS-PDX gradient around 8-9 millibars from Friday morning through Saturday.  Which means it could easily be 10 or 11 mb (or it might just be 8).  It relaxes the gradient Sunday, although that rarely happens.  Even mesoscale models try to get rid of the cold pool eastside too quickly.  Especially considering there is no weather system nearby to cause that to happen.  Note the 36 hour pressure map:

or_slp.36.0000

Classic thick dome of cold air extending all the way up to 4,000′ into Central Oregon.  At the same time 850mb temps rise dramatically westside.

850t.36.0000

They end up around +11 west of the Cascades and probably +2 eastside.  That’s quite a difference.  When you get such warm air overhead westside, it really squeezes the easterly windflow into a narrow channel down below = very windy!

And finally, the 00z WRF cross-section.  Time goes from right to left:

kttd.th

Notice the 45 kt. wind the next 48 hours over Troutdale.  Impressive, a typical strong wintertime event.  It never shows above 50kts (that I’ve seen)  We probably see this 5 times a winter, like we see 95-110 mph wind on those steps several times each winter; often when no one is there (in the middle of the night).

Tomorrow and Saturday are definitely worthy of your time out there if you have the day off and have never experienced the east wind.

A side note; the Corbett wind sensor that has operated flawlessly for 3 years died THIS MORNING.  Of course that couldn’t have happened in June, July, August, or September… so if Vista House sensor dies, there won’t be any strong wind reports from that part of the Gorge available online.

Chief Meteorologist Mark Nelsen

 

 

 

 


Yikes! Driest Air in 2+ Years Right Now

November 21, 2013

Just noticed the dewpoint is down to 8 at PDX…wow.  It’s rare to see it that low.  I did a quick plot back to November 2011 and I see we haven’t been below 10 since that time.

dewpoint_2years

Chief Meteorologist Mark Nelsen


Some Maps

November 21, 2013

Last night’s monthly run of the ECMWF, broken down into weekly 500mb anomaly maps:

500za_week1_bg_NA

500za_week2_bg_NA

500za_week3_bg_NA

500za_week4_bg_NA

Interesting that the ridging way out to our west and northwest keeps wanting to pop up.  Maybe something interesting will happen in that week 3 period.

Here’s the ECMWF ensemble chart from the 12z run today…nothing to see except the ridging over us weakens a bit:

tseries_850t_000-360_Portland

Chief Meteorologist Mark Nelsen