Cool Weather Continues, No Sign of Extreme Cold

November 4, 2013

Models are in very good agreement on the big picture over the next two weeks.  Take a look at the ECMWF height anomaly maps through the 17th of November…from last night’s run:

500za_week1_bg_NA

500za_week2_bg_NA

What do those pretty pics mean?  The large yellow (and red in the 2nd week) area is unusually high upper-level heights in the atmosphere up around 18,000′; a block in the atmosphere with very warm air aloft.  Interesting to note the block gets stronger the 2nd week…unusual.  The blue areas indicate below average heights over us and then moving slightly offshore during the period.  The 850mb (5,000′) charts show very good agreement on the pattern persisting with very few ensemble members showing spikes either high or low:

tseries_850t_000-384_Portland

tseries_850t_000-360_Portland

Here’s what I get out of this:  The upper level high is far enough west (160-170W) that cold air (what little we have in early November) will mainly dump out over the eastern Pacific and spin up into storms.  If you want an outbreak of cold arctic air here in the Pacific Northwest, you want the high around 150W.  So I don’t see a pattern to bring us an unusual early season snowfall to lower elevations.  But this pattern can be excellent for building the mountain snowpack.

Looking at this and other models, I think there’s a very good chance we’ll see some skiing within the next 2-3 weeks; before Thanksgiving.  It helps that Thanksgiving is the latest it can possibly be this year.

MarkSnow_MtHoodFcst_2013

Of course this is no guarantee…what if a warm atmospheric river rain event were to show up just before?  You never know.

I don’t see a ton of rain the next week here in the lowlands, but Thursday’s system looks like a good rain and wind producer.  Could be some 30+ mph gusts during the day Thursday as a weakening low passes by just to our north.

Chief Meteorologist Mark Nelsen


Storm Hammers Puget Sound

November 4, 2013

Models did real well forecasting the big windstorm up in Puget Sound Saturday.  200,000 customers lost electricity at one point in the storm and peak gusts hit 50-60 mph from Seattle north.  Sea-Tac had a gust to 59 mph, which is higher than anything Portland has seen since 2000!  In fact PDX has not seen a southerly wind gust higher than 53 mph in 13 years!

PDX_WINTER_OPERATIONS_2012

The windstorm and flooding weather action has definitely been mainly to our north for the past decade.  Not sure why, but I’ve noticed it since at least the December 2006 windstorm here.  That’s the one where Seattle saw a gust to 69 mph and Portland saw a gust all the way to…53 mph.  You can read all about it on Wolf Read’s windstorm site:   http://www.climate.washington.edu/stormking/December2006.html

Take a look at this video from KING-TV showing the closed floating bridge at the height of the storm:

Althougth I think I like this video better, it explains one of the reasons a new bridge is under construction, or will be soon:

The main story here over the weekend was the mountain snow.  Looks like 12-18″ has fallen at the higher ski resorts and 9″ down at Government Camp.  A nice start to the ski season…not too bad for November 4th.

Chief Meteorologist Mark Nelsen