Tuesday, October 22, 2019

Heavy Rain, Strong Warm Front, Flooding, and Model Problems

The last 24-h has brought some record-breaking rain to parts of Washington, with flooding on some rivers.   And it reveals a problem with our best weather forecasting models.  The cause of all the weather action?  A strong warm followed by an atmospheric river with lots of moisture and strong winds.

First, let's consider some of the amazing rainfall totals (from 1 AM Monday to 5 AM this morning).  Click on the  image to enlarge.

More than five inches at the cost at Quillayute, over DOUBLE the previous record for the date.   6.37 inches near Lake Quinault.  With strong westerly (form the west) winds aloft, much of the Puget Sound lowlands were in the Olympic rainshadow, with some locations only getting about a tenth of an inch.  But as the moist, warm air approached the Cascades, it was forced to rise, resulting in HUGE amounts on the western slopes of the Cascades, with one location getting nearly 8 inches.  Wow.

The action began yesterday afternoon with the passage of a potent warm front that pushed the freezing level to well over 10,000 ft.    If you were in western WA yesterday the warming during the day was pretty obvious--temperatures rising and staying around 60F. 

Below is a plot of the temperatures (red lines) and wind above Seattle Tacoma Airport.  Height is in pressure (700 is about 10,000 ft) and time increases to the left (this is called a time-height cross section).  Look at the 0C line--freezing level.   Heads straight up around 21/18-- 11 AM yesterday.  And if you can read the wind barbs, you can see the winds got very strong from the west--50 knots.

 So behind the warm front, there was a current of strong flow associated with lots of moisture and warm air--an atmospheric river.  To see this graphically, here is a model plot of the total moisture in the atmosphere at 11 PM last night.  Blue and white indicates the most moisture, followed by red.  You can clearly see the current of moisture heading into our region--that is the atmospheric river.

With such huge amounts of precipitation falling in a short period, the rivers had to respond. The latest information from the NWS River Forecast Center in Portland is predicting moderate flooding on several rivers on the west side of the Cascades, like the Snoqualmie.

To illustrate, here is the hydrograph, the prediction of river level, for the Snoqualmie near Carnation.  The river is already at flood stage and soon at moderate flood.  Make sure you don't drive on flooded roads if you live in the area.  But since this a basically a pulse of heavy rain, the river will rapidly settle down.   If you want a show today, head to Snoqualmie Falls.

The National Weather Service has flood watches and warnings out for a number of rivers of our region:

Finally, now the model problem part of the blog.    As many of you know, I am an atmospheric modeler, using computer simulation for understanding both weather and climate phenomena.  I, of course, like to see the models do well, but my most important job and that of UW graduate students and research scientists, is to note model failures and try to fix them.   The model forecast of accumulated precipitation for the event started at 5 PM Sunday (see below) got the pattern quite correct, particularly the huge amounts on the western side of the Cascades and the rainshadow over Puget Sound.  But it underplayed the amounts at Quillayute and the western side of the Olympics.

What is wrong?    A graduate student (Robert Conrick) and I are working on this problem, and we believe there is a deficiency in the physics of warm rain in the model (WRF).   This is the topic of his Ph.D. thesis and I am hopeful that we will make important improvements.  This is where science is both fun and satisfying.

Sunday, October 20, 2019

The Real Climate Debate

The real climate debate is not between "believers" and "deniers".

And not between Republicans and Democrats.

The real debate is certainly not over whether global warming, spurred by increasing greenhouse gases, is a serious problem that must be addressed.  Both sides of the real climate debate agree on that.

The real rebate is between two groups:

1.   A confident, non-political group that believes technology, informed investments, rational decision making, and the use of the best scientific information will lead to a solution of the global warming issue.  An optimistic group that sees global warming as a technical problem with technical solutions.  I will refer to these folks as the ACT group (Apolitical/Confident/Technical)

2.  A group, mainly on the political left, that is highly partisan, anxious and often despairing, self-righteous, big on blame and social justice, and willing to attack those that disagree with them.  They often distort the truth when it serves their interests.  They also see social change as necessary for dealing with global warming, requiring the very reorganization of society.  I call these folks the ASP group (Anxious, Social-Justice, Partisan).

There is no better way to see the profound difference between these two groups than to watch a video of the testimony of young activists at the recent House Hearing on Climate Change, which included Greta Thunberg, Jamie Margolin, Vic Barrett, and Benji Backer.

Jamie Margolin of Seattle talked about an apocalyptic future, with "corporations making billions" while they destroy the future of her generation.  Of feeling fear and despair.  Of a planet where the natural environment is undergoing collapse, where only a few years are left before we pass the point of no return, and where only a massive political shift can fix things, including the Green New Deal.  Watch her testimony to see what I mean.

Compare Ms. Margolin's testimony to that of University of Washington senior Benji Backer. 

Mr. Backer, leader of the American Conservation Coalition, a conservative/moderate group of young people supporting action to protect the environment, approaches the problem in a radically different way.  Instead of despair, there is optimism, recommending more scientific and technical research, a bipartisan attack on the problem, a rejection of an apocalyptic future, the building of new energy industries with potential benefits for the American economy, and a dedication to follow the science and not political expediency.  His testimony is here.

Both Ms. Margolin and Mr. Backer care deeply about the environment and want effective measures to deal with global warming.  Both their approaches and attitudes could not be more different.

We see the difference between the optimistic ACT group and the despairing ASP folks here in Seattle.

On one hand, there is the Clean Tech Alliance, which brings together technology companies, university researchers, and the business community to develop and apply the technologies that will produce the carbon-free future we look for.  Headed by Tom Ranken, the Alliance does a lot, including a highly informative breakfast series where you can learn about fusion power, new battery technologies, the future of solid waste recycling, and much more.  Non-political, optimistic, and exciting.  These are clearly members of the ACT group.

In contrast, there is Seattle's 350.org group.  They are into climate strikes, staging protests (like their recent blockade of a branch of Seattle Chase Bank), trying to muzzle climate scientists they don't like, advocating political solutions to greenhouse warming (Green New Deal), pushing divestment of energy companies, and even a Pledge of Resistance to stop energy exports by whatever means necessary.  Their "science" page has all kinds of extreme (and unfounded) claims regarding global warming impacts, like a sea level rise of 10 feet in as little as 50 years.  ASP group all the way.

I should note that the Seattle 350.org group and their "allies" oppose the Tacoma Liquid Natural Gas (LNG) Facility that will help replace the extraordinarily dirty "bunker fuel" used in ships traversing Puget Sound. LNG will also reduce carbon emissions. Scientists and regulators at the Puget Sound Clean Air Agency support the LNG facility.  But facts and protection of the health of Puget Sound residents are not priorities for highly politicized groups like 350.org.

A good example of the differences between the ACT and ASP folks is found in Washington State's recent carbon initiatives.

Initiative 732 was backed by Carbon Washington, a non-political group whose bi-partisan proposal would have increased the price of carbon fuels but was revenue neutral, giving all the funds collected back to the citizens of the State.  Carefully designed and impactful.  The work of the ACT group all the way.

But the ASP folks were unhappy.  There was no money for their climate justice and political initiatives, so they opposed it, and were joined by Governor Inslee and the environmental left.  Unforgivable, nasty attacks were made on Carbon Washington leadership by the ASP folks.   732 lost.

The ASP collective decided it was their turn, so they created a Frankenstein carbon initiative (1631), with a lowered (less effective) carbon fee, but one in which climate justice groups and political allies on the left would have control, and were hardwired for much of the funds.   The main advertising line of the 1631 ads:  catastrophe was around the corner and the big oil companies were to blame.  1631 was an election day disaster, losing by 13 points, and the ASP folks have probably killed any hope for an effective carbon tax/fee in our state.

What about the media?  Which side are they on?  ASP or ACT or neither?

Much of the "mainstream" media parrots the message of  the ASP side.  The Seattle Times is a great case in point, with headlines of massive heat related deaths (750 die per event!) and catastrophic wildfire seasons that have no basis in good science.  But there are plenty of others, such as the LA Times and the NY Times.    There are some major media outlets that are more balanced (such as the Wall Street Journal).   A major issue for the media is the hollowing out of science reporting, with most climate stories being handled by general reporters with neither the time, background, or inclination to get beyond parroting the press releases of activist groups or evaluating the claims of speculative research papers.  It has gotten so bad that a recent headline story in the Seattle Times kept on talking about the WRONG GAS (carbon monoxide instead of carbon dioxide).

A Religious Movement

In many ways, the ASP group appears to be a religious movement, not unlike the many millennialist movements of the past.  As other groups in the past, they predict an apocalyptic future (including fire and brimstone!) and that one must "believe" in their viewpoint or be rejected as a "denier."  The ASP folks have a holy viewpoint that comes from authority (they claim based on the views of 97% of scientists).  There is no debate allowed, the science is "settled."   Sounds like religious dogma.

The ASP movement describes a world that is teetering on the edge, with mankind's days numbers (10 or 12 years according to several of their leading prophets) unless immediate steps are taken.  They constantly repeat that the threat is existential.

They believe it is ok to distort the truth to get folks "to do the right thing."   The ASP group has well defined "enemies" that represent true evil (Trump, Republicans, Big Oil, Koch Brothers) and they support attacking and silencing those they disagree with (my past blog gives you some documented examples of such behavior).  ASP has their priests (Al Gore, Bill McKibben, Michael Mann) and even young saints (Greta Thunberg).  As in many such movements, members are guided to act in approved and enlightened ways, but the leadership does not need to follow the rules (e.g., many ASP "leaders"  have huge carbon footprints from flying).  Importantly, ASP sees their work going much further than a technical fix for technical problem, but as a "social justice" movement that will change the very organization of society.

Disturbingly, the ASP folks are against key technologies that could really make a difference, such as nuclear power, and are relatively uninterested in working on adaptation and resilience to climate change.   Many do not support dealing with our forests in a rational way (e.g., restoration with thinning and prescribed burning) but would rather blame it all on global warming.

By pushing a highly political agenda the ASP movement is undermining bipartisan efforts--and nothing important will be done unless both sides of the aisle are involved.  ASP folks love to say that the Republicans are unwilling to deal with climate change, a totally unfair claim.  I have talked personally to leading WA Republicans, like Bill Bryant and Rob McKenna.   They acknowledge the seriousness of global warming and the need to act.  In my talks in highly Republican eastern Washington, growers and others accept the problem and want to work on solutions.   Under a Republican U.S. Congress, funding for climate research has been protected and increased.  But partisan attacks by the ASP group is seen as a way to promote group cohesion and the "evil" of the other side.  Calling others names is not an effective way to secure their cooperation.

A problem for the ASP group is that their message is so dark, pessimistic and depressing that it tends to turn others off.   And it has a terrible psychological effects on its adherents and those that listen.  Fear, anxiety, feelings of hopelessness, despair, and rage.  There are even classes on dealing with eco-anxiety and climate grief.  Greta Thunberg said that the worry ruined her childhood.

And yes, there is President Trump.   Much of what he says on climate change is simply nonsensical, and quite frankly he is not part of the debate.  Republicans in Congress do not follow his lead.  But he is a convenient foil for the ASP folks, who use him for their own purposes.

The Bottom Line

Progress on climate change is being undermined by the efforts of the highly vocal, partisan, and ineffective ASP group.  They are standing in the way of bipartisan action on climate change, efforts to fix our forests, and the use of essential technologies.   They are a big part of the problem, not the solution.

In contrast to the ASP folks, the ACT group generally tries to stay out of the public eye, quietly completing the work  needed to develop the technologies and infrastructure that will allow us to mitigate and adapt to climate change.  In the end, they will save us.  That is, if the ASP folks don't get in their way.

Friday, October 18, 2019

Huge Precipitation Contrasts

Sometimes you just have to be amazed by the precipitation variations in our region.  On the southwest side of the Olympics near Lake Quinault there was 6.78 inches of rain during the past 72 hr.   That is more than Seattle typically gets in a month during mid-winter.  But on the other side of the range, there was only .37 inches in Sequim and .19 inches on the southern side of Lopez Island in the San Juans.   With flow from the southwest, there was huge upslope enhancement on the southwest side of the Olympics and profound rain shadow to its lee. 

To put it another way--- there was 37 times more rainfall on one side compared to the other.

 Puget Sound was also  rainshadowed by the Olympics, with a third to one-half inch.  But as the air rose again on the Cascades, the precipitation increased to 3-4 inches over the same period.

The new GOES-17 satellite provided a full color view of the rainshadow, demonstrating that the there can be sunny skies in its core, while everyone else is under clouds.  No wonder folks retire there. Here is the view at 2:10 PM on Thursday, which is a good illustration.

Weather radar can be used to estimate rainfall, and the total estimated accumulation for roughly the last 3 days, based on the Camano Island radar (below), shows a rain shadow that extends down to Seattle.  There is a huge increase south and west of the city--shows how sharp the boundaries of the rain shadow can be.

One of the most exciting aspect of modern high-resolution weather prediction is that we can predict such extreme precipitation contrasts, as illustrated by the 48h accumulated precipitation ending 5 PM Thursday (below) from the UW ultra-high resolution (4/3 km grid) domain.  Big impact of the Olympics, and if you look closely you can see the effects of Mt. Rainier.

This weekend we have plenty more rain, but I have some good news--by the end of next week, upper 50s and dry conditions should return. 
Portland Oregon talk.    I will be speaking next Saturday (Oct 26th) in Portland (OMSI) at 9 AM.  My topics?  The Blob and Wildfire Meteorology.  This is the big annual meeting of the Portland Chapter of the American Meteorological Society.  More information here.

Wednesday, October 16, 2019

The Blob is Weakening

 It is sad but true.  The Blob, the area of above normal sea surface temperatures in the northeast Pacific, is weakening, particularly near the U.S. West Coast.

The plot of the sea surface temperature anomaly (difference from normal) for today (Wednesday) shows normal or even below normal sea surface temperatures along the west coast and extending well offshore of the Northwest.  This is a major change over the past few weeks.  A few months ago the sea surface temperatures off our coast were roughly 5F above normal.  No more.  There is still some BLOB warmth further offshore, but I suspect that will weaken over time now.

Another way to see that change is to look at one of the offshore NOAA buoys.  Take buoy 46089 located off the Columbia River (see map)

In early September, the sea surface temperature at that location was up to around  67F, which is very warm.   The temperatures have fallen to about 60F today, a large drop of 7F.

Other buoys have shown the same thing.

Why the change?  The upper level flow pattern has changed dramatically.  Well into September there was anomalous high pressure over the Pacific (red colors below, Sept 22-28).  High pressure is associated with light winds and weaker than normal mixing in the upper ocean. With less mixing of cold water to the surface, the surface temperatures are above normal.

But the pattern has really changed recently, with below normal  sea level pressure (low pressure systems with strong winds) now over the Gulf of Alaska.  Bad for the BLOB.

We are now going into the stormy season for the North Pacific and it is unlikely that conditions will be good for the BLOB.  Expect more weakening during the next week.

And this is all good news.   Excessively warm water in the NE Pacific is bad for the marine food chain, leading to poor salmon runs and other problems.  So although the Blob may be sad, this is positive news for everyone else.

Monday, October 14, 2019

The Meteorological Switch is About to Be Turned On

It is not unusual for the first few weeks of October to be relatively dry and sunny in the Northwest.

But quite typically, something happens during the third week of the month..  The jet stream sags south, storms--lined up in the Pacific-- make their way into the region.

A series of Pacific cyclones and fronts are lining up to visit us

And this year will be no different, with the first of a line of systems reaching our shores Wednesday morning.   It is going to be wet, so get your rain gear ready.

The first two weeks of October have been cool, but dry.  Perfect fall weather that seems to have enhanced the quality of autumn colors.  Here in Seattle, we  have received about .25 inches of precipitation, while normal is about 1.3 inches.   My soil is quite dry, even after a wetter than normal September.

But everything changes Wednesday morning as the first Pacific front (evident in the satellite image above) reaches our coast.  Below  is the forecast precipitation total through 5 PM Thursday.  The region is soaked, with over two inches in the mountains, but only about a half inch in the rain-shadowed lowlands.

But this is just the warm up.  The next 72 hours?  Still more, particularly over Oregon.

Now let me show you a state of the art precipitation forecasting tool:  a plot of the precipitation forecasts for Seattle from the European Center--the best in the world.  And we will look at their ensemble of many forecasts--looking at one forecast doesn't give you an ideas of the uncertainties of the prediction.

Each horizontal stripe is an individual forecast (there are 51 of them) and the colors give you the daily forecast totals.  The bottom panel shows you the mean of the many forecasts (ensemble mean), often a very good forecast.  You are seeing the forecasts from today to October 29th.

Lots of rain on Wednesday and Thursday in nearly every model run.  Plenty of rain after that.  You can be confident in the rain forecast.

The slugs and ducks will be happy!

Saturday, October 12, 2019

Northwest Contrails and Global Warming

The new GOES-17 weather satellite, with its higher resolution imagery, does an excellent job in showing the contrails that often form over our skies.

For example, the visible image at 7:51 AM this morning shows contrails (the white lines) near the Oregon/Washington border (see below)

And there were plenty over Oregon and northern California at the same time.

As described in previous blogs, contrails form as combustion from burning jet fuel injects moisture and small particles into the cold, upper atmosphere, producing a line of ice crystals behind the plane.

What is less well known is the significant net low-level warming effect of such contrails.

Why did I say, net warming effect?  Because contrails both warm and cool, with the warming dominating.

Let me explain.    On one hand, the ice crystals in contrails cool the lower atmosphere, since they reflect some of the sun's radiation in the visible part of the spectrum back into space.  But the ice clouds associated with contrails also influence radiation in the infrared (long wave) part of the spectrum.   Such clouds can absorb infrared radiation coming up from below and can emit infrared radiation back down to the surface.  This acts to warm the lower atmosphere in a similar way that greenhouse gases such as carbon dioxide and water vapor do.  Think of a big blanket aloft.

It turns out that the warming effects are larger than the cooling effects:  thus, contrails have a net warming effect.

The IPCC (Intergovernmental Panel on Climate Change), encompassing scientists from all over the world, have analyzed the contrail warming and has found it significant, but smaller than the overall  impacts of increasing CO2.  In 2005, it was estimated that aircraft provided about 5% of the global warming forcing, with the contrail effect being the largest component--greater than the warming from the CO2 released by burning jet fuel.  And aircraft mileage is increasing rapidly.

The jet contrail warming will be a very difficult contribution to lessen, since only fossil fuels can provide the energy densities needed for commercial aircraft.  Fortunately, it only represents a small proportion of the problem.

Thursday, October 10, 2019

Triumph in Northern California

This was a historic day.

Today there was a major Diablo wind event in northern California, with winds gusting to 70-80 mph from the northeast in favored locations.

But no major fires were started.  No cities or town burned down.  And there were no wildfire deaths.

A major achievement.

In comparison, two similar events in 2017 and 2018 killed dozens of people and caused tens of billions of dollars of damage.

The big difference?  Pre-emptive power outages by PG&E.

The winds were formidable and the relative humidities were low.

To illustrate, here are the maximum winds since midnight around the Bay Area ((October 10, 2019).  One can spot maxima of 73, 77 and 75 mph, with lots of wind about 40 mph.

The west slopes of the Sierra Nevada were windy as well, with winds gusting to 40-50 mph on the mid-slopes of the western side of the Sierra Nevada.

High-resolution weather prediction models correctly predicted the evolution and magnitudes of the winds, including the CANSAC model system run by DRI in Reno, Nevada (see below for 8 AM this morning) and the NOAA/NWS HRRR model.  Just as important as forecasting the strong winds, was the prediction that the winds would weaken during the afternoon, allowing power to be restored.

The avoidance of disaster today was particularly impressive, consider the wet winter and spring led to bountiful growth of flammable grasses.

Increasingly skillful weather forecasts are on the front line of protecting people from natural hazards, be it wind-driven wildfires, hurricanes, floods, and strong thunderstorms. 

Such excellent predictions do not replacement the hard work of making our civilization better adapted for the natural environment, such as ensuring that folks don't live in vulnerable locations (urban-wildland interface, vulnerable coastlines, unstable slopes and more) or properly taking care of tour coastal zones and forests. 

But good forecasting is a potent tool and can buy some time to complete the infrastructure changes needed to be resilient to extreme weather in the natural world.

Update:    Strong Santa Ana winds in southern California have resulted in fires growing last night.

My blog on UW College of the Environment Censoring of Social Media is Here.

Tuesday, October 8, 2019

Snowstorm in Stevens Pass

You don't have to wait for skiing and snowshoeing....there is a veritable snowstorm going on right now in Stevens Pass.

Snow and slush are covering the roads

And watch this video of what it was like in the pass

And the ski area looks like a winter wonderland.

Right now there is TEN INCHES on the ground and snow is falling at roughly 2 inches and hour:

The reason for this white bounty? Cold, unstable air is moving off the ocean and being forced to rise by the Cascades.

But there is more.  In the central Cascades the snow is being supercharged by an intense Puget Sound convergence zone, produced by converging airstreams form the north and south (see satellite image).  This is a strong one.

So if you want to experience an amazing early snowfall and get some cross skiing in today, head to Stevens Pass.  Want clear skies and sun?  Head to the south Sound.

And one more thing...some of the snow is getting down to 1200 feet, in the eastern suburbs, something reported by Dr. Peter Benda of Bellevue.

My blog on UW College of the Environment Censoring of Social Media is Here.

Cold Air and Snow Back in the Northwest

It is snowing right now at Stampede Pass at 4000 ft in the central Washington Cascades.  At Stevens Pass, at a similar altitude, there is snow and slush on the roadway (see below).  An image that will warm the heart of any Northwest skier.

The upper level pattern associated with the influx of cold and precipitation is a classic and may be familiar to a regular reader of this blog (see below).  This 500 hPa pressure level map (about 18,000 ft above sea level) shows a big ridge of higher pressure/heights over the Pacific, with a sharp, well-defined trough moving southward into the Northwest.

Memorize this pattern.  It is the one that brings lowland snow after November 15th.   Alas, temperatures are too warm for that  this early in the season (something that brings a smile to all snow-challenged Seattle mayors).

Satellite imagery show cold, unstable air approaching western Washington and Oregon.  You see the popcorn like elements off the coast?  Those are convective showers--intermittent rain for us near sea level, snow showers above roughly 4000 ft.

With westerly (from the west) flow aloft, the western side of the mountains will get plenty of precipitation as the air is forced upwards.  To illustrate, here is the forecast total through 5 PM tomorrow.  1-2 inches of precipitation could fall west of the Cascade crest and profound rain shadowing over the Columbia Basin of eastern Washington.   Want dry conditions and some sun?   It is available.

But what many of you really want to know about is snow.  The forecast total through 5 AM tomorrow (Wednesday) shows snow above roughly 3300 ft, with up to a half-foot in favored locations.  The Rockies and its eastern slopes get hit hard again.

And for snow/cold lovers I have more good news.  The Blob offshore is weakening with sea surface temperatures off the Northwest coast returning to near normal.

Want more good news?  The latest European Center 46-day forecast is going for colder than normal temperatures through November 22 (see below, blue color is below-normal temperatures).   Time to wax your skis.

Image courtesy of WeatherBell


My blog on UW College of the Environment Censoring of Social Media is Here.