Saturday, October 18, 2014

The Extraordinary Minimum Temperature Heat Wave in the Northwest

I have been watching Northwest weather for a long time and I have never seen anything like what we have experienced during the last month:  

An extended and intense minimum temperature heat wave.

Something amazing has been going on this fall, and for some reason the Ebola-crazed media hasn't picked up on it.   But that is why we have blogs.  Gardeners know something weird is happening. Vegetable plants are not dying.   Tomatoes are still ripening.

There are movies about this issue.

Here are the temperatures at Seattle-Tacoma Airport during the past 4 weeks, with the average high (red) and lows (blue) shown.   Only ONE day in that entire period has seen the temperature dropping to the average low.  For most days, our minimum temperatures have been 5-10 degrees above normal. Our minimum temperatures last night were close to the average maximum for the date!
UPDATE MONDAY MORNING:  Here is the latest 4 weeks.  Our low temperatures the last few days have been around the NORMAL HIGHS.  And yesterday broke the record daily high at Sea-Tac Airport.

And this is not Seattle alone, here is the same trace for Bellingham.  Same thing.  Bellingham cooled to 59F last night!
Or Quillayute on the coast.   Mega-warm.
A plot of the minimum temperature anomaly (difference from climatology) for the western U.S. over the past month shows that our regional is RED HOT, with minimum temperatures 6-8F above normal on average.

A close-up over Washington State shows some areas are 8-10F above normal.


And the latest NOAA Climate Prediction Center extended forecasts show no end in sight
to the warmth:


Now why is this happening?   This is an important  question because one can expect some folks in the media and advocacy groups to start saying this is a "sign" or "consistent with" global warming due to mankind's emissions of greenhouse gases.  There is no reason to think that is true.

There are two main reasons for the warmth and they are both associated with the anomalous atmospheric circulations we are having.

Reason #1:  a persistent area of low pressure over the eastern Pacific.  The figure below shows the sea level pressure anomaly (difference from normal) for the past month.   There is an area west of us with pressures well below normal.   Such anomalous low pressure is associated with stronger than normal southerly and southwesterly winds over us that blow in warmer than normal air.
Here are the wind anomalies near the surface for the same period...look closely you will see they are southerly over us. It all fits.

This is probably the major cause.   Then there is something else, something I have talked about in previous blog:  the warm water BLOB off the coast.

Below is the sea surface temperature anomaly map for the past week.  You see the orange and red colors off the coast that indicate temperatures 2-4F above normal?  The BLOB still lives.  So air passing over the eastern Pacific  is exposed to warmer than normal water.  Me like BLOB, BLOB is good.

As I noted earlier, the BLOB has little to do with global warming but was produced by anomalous high pressure over the Pacific last winter and year.

So our ridiculously warm temperatures this fall are being produced by an unusual combination of high pressure a year ago that produced the blob and low pressure this fall that is bringing up warm air from the south.

There is no reason to think that these circulation anomalies are caused by human greenhouse gas emissions.  And remember that the eastern U.S. has been colder than normal.

Well, time for me to go out to my garden to harvest some more red tomatoes.


Wednesday, October 15, 2014

The Western Puget Sound Rain Shadow

In Seattle, it was quite a wet, blustery day, but if you had taken a short ferry ride to Bainbridge Island you would have experienced hardly a drop.  To illustrate this, here is the 24hr precipitation ending 8 PM Wednesday over Puget Sound and nearby environs.

.01 inch in Bainbridge...barely enough to wet the pavement and .02 inches in Belfair on the Kitsap Peninsula.  Cross the Sound and there was over .40 inches.  In general, it was much drier on the western side of the Sound.  Yes, Sequim to Port Townsend were fairly dry too.


As you might imagine, this contrast was due to rain shadowing in the lee of the Olympics and upslope enhancement on the western side of the Cascades.   We could watch it happening in today's weather radars (showing you the radar-based 1-hr precipitation)

11 AM.  Rain shadow NW of the Olympics, consistent with SW flow.

 At 12:59 PM, the flow was in transition (becoming more westerly) and you notice an increase in precipitation on the western side of the Cascades)

This transition was even more obvious at 3:46 PM,  A broad rain shadow downstream of the Olympics was obvious, as was the substantial enhancement of rain on the western side of the Cascades.


Even more so at 5:02 PM


We did have radiosonde launch at Qullayute at 4 PM and here is the sounding of winds (barbs), temperature and dew point (the dark lines slanting to the left).  Height is in pressure units (hPa), with 700 being 10,000 ft, 850 about 5500 ft., etc.).  Winds approaching the Olympics were from the west-southwest at that time, which fits the radar pattern.


My point is that Olympic rain shadows don't only hit Sequim and environs, they can extend down the eastern slopes of the Olympics under the right conditions.  And it also illustrates that if you are weather-wise and are ready to travel an hour or so, you can often find much better weather.  Or stormier weather if you prefer.


Monday, October 13, 2014

Waterspout Hits Southern Puget Sound: First Tornado Warning Here in 17 Years

On Saturday around noon, several of you were startled to get a tornado warning on your smartphones.

The cause: a waterspout that developed near Anderson Island in the southern Sound and which remained intact for about a half-hour.   Here are some pics I found on the KOMO and KING-5 web sites.   An extremely well-formed funnel and you can see from the first that the winds reached the surface, kicking up lots of spray.  Beautiful pictures.


Waterspouts are the weaker cousins of the strong tornadoes one finds over the Midwest U.S.
According to the official Storm Prediction Center definition:

 A waterspout is a tornado over water--usually meaning non-supercell tornadoes over water. Waterspouts are common along the southeast U. S. coast--especially off southern Florida and the Keys--and can happen over seas, bays and lakes worldwide. Although waterspouts are always tornadoes by definition; they don't officially count in tornado records unless they hit land. They are smaller and weaker than the most intense Great Plains tornadoes, but still can be quite dangerous. Waterspouts can overturn boats, damage larger ships, do significant damage when hitting land, and kill people. 

This waterspot, and virtually all of our waterspouts/tornadoes around here, are associated with non-supercell thunderstorms.  Supercells are the big Kahunas of the thunderstorm world with very high tops (reaching 40-60K ft), intense rain, hail, and most importantly rotation.

This waterspout came out of a relatively wimply NW thunderstorm.  Let me show you.  We start with the composite reflectivity--a measure of the highest precipitation rate in the storm. Got some red...that is pouring rain, probably with some small hail in the south Sound. Impressive for around here.  But equally strong thunderstorms were hitting in the north Sound with no waterspouts. No sign of any hooked echoes...which indicate  supercell storms.


How high were the thunderstorm tops?....we have a radar-based diagnosis of this.  Only 20,000 ft!   Folks in the Midwest would laugh at such tops.



And since the National Weather Service radar is Dopplerized, it can show the radial winds toward or away from a radar.  Neither this shot from the Camano Island radar nor one from the Langley radar showed any hit of thunderstorm rotation as we would see in a supercell storm.  Rotation would be indicated by a pairing of warm (red,orange) and cool (green, blue) colors.  Nothing there.


Nearly all of the waterspouts and tornadoes in our area are from the non-superstorm type.   That usually involves a fairly strong thunderstorm passing/developing over a region where the wind changes rapidly with horizontal distance.   We call that horizontal wind shear.  Such wind shear is associated with some inherent rotation around a vertical axis that get spun up by the vertical motion of the thunderstorm.   A schematic of this effect is shown below and I have a whole section on this process in my book on Northwest weather (which is a good gift for the upcoming holidays by the way).


Looking at the surface map at noon on Saturday (see below), I wasn't impressed by the amount of shear, but clearly there was enough.  Perhaps we had 15 knots over southern Puget Sound and much weaker wind over land (Kitsap, Anderson Is.).


Most Puget Sound tornadoes seems to develop on the shear associated with a Puget Sound convergence zone or the strong wind shear near terrain.  This one appears to be an exception.

The last time a Tornado Warning was issued for the greater Seattle Metro was on  Dec. 12, 1969, so the younger folks reading this blog will never have experienced such excitement.


Dawg Dash:  Weather Looking Decent!

 One of my favorite events will occur Sunday morning at 9AM:  the UW Dawg Dash fun run.  For more information, check out their site: http://depts.washington.edu/alumni/blogs/dawgdash/  The latest forecast suggest no major storm at that time.  Little or no rain.

Saturday, October 11, 2014

Wimpy El Nino

We are now close enough to the winter season to have a fairly clear idea of the El Nino situation ahead.  Remember that El Ninos are associated with warmer than normal water in the tropical Pacific and that such anomalies can influence Northwest weather (less storms, warmer, less snow).

Originally there was a lot of talk (last spring) of the potential for a Super El Nino, with some of the global warming "advocate" sites talking about its effects on the global temperature record (global temperatures can warm substantially with strong El Ninos).



However, the sea surface temperatures in the critical  central Pacific is only modestly warmer than normal and the atmospheric circulation has not reacted in a way to reinforce the warming and push us towards a moderate or stronger El Nino.

Let's start with one of the key measures:  the sea surface temperature in the Nino 3.4 area of the tropical Pacific.  The official definition of El Nino is an anomaly  there greater than .5C.  We are not there now and in fact the SST has declined recently.


A number of groups run statistical and full-physics models to simulate El Nino.  They suggest we will have an El Nino, but a weak one.  However, verifying these models for the forecasts started earlier in the year, suggest they have been pushing warming in an unrealistic way.


The National Weather Service Climate Forecast System (CFS) model is now going for an entirely marginal event, barely reaching the .5C criterion


And the official probabilities for El Nino are now only about 65%.


So we should not expect much more than a marginal El Nino during the upcoming fall and early winter months.  And amplitude matters.   Weak El Ninos have lesser impacts.

The correlation of our weather with El Nino is not perfect to start with.  And for weak El Nino years the relationship weakens further.

Let me illustrate this for you.

Here are the precipitation patterns across the U.S. for some STRONG El Nino years.  The most consistent implication is  the wetter southeast U.S.   There is a tendency for southern/central California to be wetter.  The Northwest is less consistent.



But for weak El Nino years, the precipitation patterns are all over the place.  I would not place bets on anything.  This is the story of our upcoming winter unless El Nino revs up unexpectedly.


So based on the correlation with El Nino, we have very little guidance for the upcoming winter. Sorry.

The latest NWS Climate Forecast System forecasts for December-January-February is for warmer than average over much of the U.S.  No hint of the feared "polar vortex."
What about precipitation?  Very little signal over the Northwest.  But wow...California is much wetter than normal.  This would really help the drought.  Fingers crossed.

And this week should be a shock to some.  Showers today.  Generally dry on Sunday and Monday day.  But they the celestial spigots will turn on.

Hopefully, the rain will be over by next Saturday.  Why?   Because one of my favorite events will occur Sunday morning at 9AM:  the UW Dawg Dash fun run.  For more information, check out their site: http://depts.washington.edu/alumni/blogs/dawgdash/


Wednesday, October 8, 2014

Seattle's Bicycle Superhighway Disintegrates: Why Doesn't the City Care?

One of Seattle's jewels is the Burke-Gilman trail, a bike and pedestrian trail that stretches across northeast Seattle for many miles (see map).  Originally the path of regional freight rail lines, the Burke-Gilman is now a major commuting route for thousands of individuals,and an important


recreational corridor for cyclists, pedestrians and joggers.  Over ten thousand people use the trail each day, with roughly a thousand cyclists an hour passing through the University of Washington portion during afternoon rush hour.  It is Seattle's bicycle superhighway.

But now the bad news.  The city has allowed the Burke-Gilman to deteriorate to a point that it is no long safe.   Tree roots have created severe undulations and major cracks in the asphalt surface, the edges are sinking or breaking away, hole and hollows have formed, and I am just warming up describing the dangers.   Bicyclists are not only experiencing unpleasant rides, with broken spokes and tires, but the decline has resulted in accidents, some with major injuries.  I have been hurt myself.


I have commuted to the UW along the trail for several decades and NEVER has it been in worse shape.

To put it bluntly, this is a disgrace for a great city.  And a double disgrace for a city that likes to think of itself as environmentally forward thinking and concerned about reducing the carbon footprint of its citizens.

But don't take my word for it, let me give you a sample of the current state of the trail (I took my camera with me this week)

Here is a section just north of my home.   Huge dangerous bump.  So bad they painted the crack and put some cones up.  A few years ago, a cyclist hit a bump at this spot was thrown off his bike and seriously injured (taken away in an aide car!).   The city did a very poor fix and the bump was back a few years later (as shown below).  


A bit further down the trail, a big hole, more root heaves, and more cones

And another.

And another
And another

Want to take a dip?  Several "holes" a few inches deep. Hit that at night and see what happens.


Large section have cracked and degraded asphalt, with edges broken and yielding to invading plants. You what happens to your bike when you hit abrupt edges?  You fall.



The bridge over 35th Ave. NE used to be fixed properly with new wood slats.   Now they just put odd pieces of wood over holes.


I have a dozen other pictures of huge bumps, cracks, falling edges, undulations, and other major problems with the trail.   But you get the message.  When the city has tried to fix sections, they generally did a superficial job (not going down deep enough to deal with the roots); thus, the "repaired" sections quickly degraded.

It simply does have to be this way.  Want proof?  Take a trip on the trail across the city's northern boundary into Lake Forest Park and you will be in trail heaven.  Let's take the trip!

We are just about to cross the northern limits of Seattle!


Mama Mia!  Bicycle nirvana.  Wide trail. Smooth as silk.  No abrupt edges.  No root heaves.  Nice benches and garbage cans.


Street crossings are beautiful.  Clearly marked with warning strips.


Wow...this trail is good enough to be added to the rail-trail hall of fame!


I turn around and return to Seattle and back to this.


Every Seattle Council member, the mayor, and the heads of the transportation and parks departments should visit the Lake Forest Park portion of the trail. They should hang their heads low in shame.   Shame for needlessly endangering the lives of so many Seattle residents.

But it is worse that this.  While the trail is rotting, large amounts of money has been wasted on other "sexier" bicycle projects.  For example, the city spent hundreds of thousands of dollars to change 125th St. NE from two to one lanes, with a bicycle lane on both sides.  Total waste of money since few cyclists want to travel up the very steep grade of 125th.  And it has caused traffic jams on 125th.  Great idea.


Then the city spent hundreds of thousands of dollars putting bicycle symbols all over the roads (called sharrows), as if they were going to make cycling any safer (see below).   I bet some bureaucrat is proud of this "innovation."


And the latest waste of money is the 4.4 million dollars being spent in putting bicycle rental kiosks around parts of the city.  Does someone really think this is a solution to anything?


So it appears there is a lot of money available, but no one in the city bureaucracy gives much priority to maintaining the trail.   Or in creating an absolutely protected bike route into the city.  Ironically, Mayor McGinn, supposedly the "bicycle mayor",  did very little to improve the trail or city bike lanes in general. Hopefully, Mayor Murray will do better.  I wonder how many lawsuits there have been regarding crashes caused by poor trail conditions.  How many will it take before the city takes maintaining the trail seriously?   Better to invest in fixing the trail then payouts for expensive lawsuits.

The importance of the trail is only going to increase as light rail reaches the University of Washington.   Best estimates suggest that bike traffic will radically increase as folks cycle to the train station to catch rail to downtown Seattle and elsewhere (see graphic).


The University of Washington transportation department has drawn up plans to improve the Burke-Gilman trail on campus, but lacks sufficient funding to initiate the plan.  Considering that the trail serves the entire city, why aren't local governments footing the bill?

One also wonders why the city is not trying relatively inexpensive approaches to dealing temporarily with the root heaves and undulations, such as asphalt grinders (see picture below).  They are not expensive.  And there are a number of local companies that specialize in such work.


It seems amazing that a city that is so concerned about global warming and environmental issues is doing little to facilitate a no-carbon form of travel.  And that city bureaucrats have little interest in maintaining their bicycle superhighway.

Welcome to the University of Washington portion of the Burke-Gilman Trial

But lack of vision and leadership in city/county government does not stop there.  Just consider the deplorable state of our bus transportation. Virtually every time I try to travel northward out of downtown during rush hour, I find packed buses--with frequent wait of 2-3 buses before there is a space for me.   Bus service out of south Lake Union is the same.  Instead of adding bus service to facilitate rush hour commuters and attract more users, Metro has been talking about bus cutbacks. This is failed leadership.  Unworthy of a forward looking, progressive city.

An initiative will be placed before Seattle voters to provide money for more bus routes.  Pass it and use the funds to radically improve commuter bus service.


I think the citizens of Seattle have to make it clear to our political leadership that we expect a different approach, with rapid action to repair the trail, build a protected bike lane into downtown, and fix the inadequate bus service.  The current situation is an embarrassment of a supposedly world-class city.

Personally, I am worried for my own safety as a bicycle commuter.   Commuting home on dark, wet nights will soon be made much more dangerous due to the bumps and sharp trail edges.  Many of them will invisible under the fall leaves.  I have taken several tumbles in my years of commuting, and hope I won't be seriously injured this year by another.  But I will keep on commuting by bike.  It is a wonderful way to get some exercise, saves lots of money, reduces my carbon footprint, and allows a relaxing commune with nature.  Many of us love the trail.  But it is endangered and needs our attention.


IMPORTANT INFORMATION:

The Burke-Gilman Trail in Seattle is the responsibility of Seattle Parks and Recreation

The acting superintendent is Christopher Williams.  Perhaps you might want to let him know your feelings about the trail:

Christopher.Williams@seattle.gov

Further Comment:

There  has been quite a bit of push back regarding my comments about the 125th St. road "diet."    My point is that money is limited.  The same amount of funding could have fixed the trail I suspect, with far more positive impact for cyclists.   My more general point is that there are a lot of expensive pet projects funded (e.g., the south lake union trolley), but no comprehensive view of what is needed and no real prioritization for the high-impact projects