Thursday, April 23, 2015

Wetter weather ahead for Friday and Saturday

In a year with low snowpack, getting rain during mid to late spring is crucial for reducing water problems during the summer.  The water delays the beginning of watering/irrigation season, leaving more water for later use.  And the water can go right into the region's reservoirs, which no longer have to worry about holding storage for potential flooding.

The past 24h brought a few tenths of an inch over the region, and nearly 3/4 of an inch over the windward side of the Olympics (see graphic).


And some wet prospects are ahead:   here is the National Weather Service GFS model forecast for cumulative rain over the next ten days. Western Washington and the Cascades do well, at least several inches, and even northern California gets moderate rain.



Friday and Saturday will be influenced by an upper-level trough that will maintain cool, unstable air over us (see upper level map for Friday morning),   Typical spring shower regime with low snow levels.

Looking at the next 72 hr precipitation over the Northwest from the UW WRF model, there is substantial rainfall ahead, with 1-2 inches of liquid water over the North Cascades and Olympics.


Perhaps more importantly, some of this precipitation will be mountain snow with 1-2 feet in portions of the north Cascades.


The latest extended forecast by the NOAA Climate Forecast System model (CFSv2) for the next three months is suggesting normal precipitation, except for right along the coast (see map).
I believe the media and some local politicians have gotten a bit too worried about our "drought."   We have not had a precipitation drought at all....we are in a snow drought due to warm temperatures.  The situation is unique and I suspect we will weather this summer far better than expected.  And for those looking for outdoor activities this weekend:  Sunday morning and early afternoon look the best.

Tuesday, April 21, 2015

The U.S. Air Force Turns to a Foreign Weather Forecasting System

The United States Air Force has decided to drop its American weather prediction system (the Weather Research and Forecasting model, WRF) for the forecasting system developed by the United Kingdom (UKMET Office Unified Model).

As described below, this decision is a terrible mistake and will ensure substantial damage to U.S. weather prediction capability, waste precious financial resources, and  undermine the U.S. Air Force's capacity to provide the best possible forecasts for U.S. pilots and Air Force operations.


This blog will tell you about this unfortunate situation, document a flawed decision-making process, describe the downside of this decision, and call for better-informed public officials and legislators to intervene.

The current situation

Today, the US Air Force makes regional forecasts around the world using the WRF model.  WRF is an extraordinary success story;  developed at the National Center For Atmospheric Research  (NCAR) in Boulder, Colorado, WRF is used by thousands of users in the U.S., and is the predominant model used in the research community and the private sector.  WRF is also heavily used by the National Weather Service and by many thousands of individuals, groups, and weather forecast entities around the world.    WRF is probably the best example of a community model: highly flexible, state of the art, adaptive, with advances from the research community flowing into the effort, resulting in constant improvement.


During the mid-2000s, the AF took on WRF as their main regional modeling tool, using the U.S. global GFS (Global Forecasting System) model for their global predictions.  The global model is used to provide boundary conditions for the regional model (WRF).

The AF adoption of WRF was a win-win for the nation.   AF funding contributed to maintaining and improving WRF; in fact, the AF was the largest financial supporter of WRF.   The AF in turn had the best possible regional model, one that was easy to use and highly capable, and a model that took advantage of the efforts of the vast U.S. weather research community.   An improved WRF helped drive U.S. weather modeling research and was taken on by many private sector firms.  The U.S. was clearly the world leader in this domain.

The Air Force fumbles

Late last year it became known the Air Force Weather Agency, which runs AF numerical forecast models, had decided to drop WRF and NOAA's GFS model, and turn to a foreign modeling system:  the UKMET office model.   A recent story in the Washington Post discussed this decision.   This decision was made without talking to U.S. national weather modeling partners (the National Weather Service and the U.S. Navy) and appears to be the decision of one individual, Ralph Stoffler, acting head of the Air Force Weather Agency.  Mr. Stoffler was an AF weather officer and has a BS in meteorology.

Ralph Stoffler

Checking with my contacts in the Air Force, I have learned that there were no long-term verification/comparison runs to demonstrate that the the UKMET office model would be superior to WRF.  It is stunning that such a major decision would be taken without strong evidence of improvement.

Mr. Stoffler's plan greatly expands AF modeling into the global arena, moving to DUPLICATE the U.S. global prediction efforts completed by the National Weather Service and the U.S. Navy's Fleet Numerical Meteorology and Oceanography Center.   There has always been an unfortunate relationship between Navy and Air Force weather operations, with substantial duplication of efforts.   But the new AF plan goes beyond this and is highly wasteful of U.S. weather prediction resources.

To run a state-of-the-art global model requires large resources, including the acquisition and quality control of vast amounts of data from many different satellites.  A high-resolution global model also demands huge computer resources. Clearly, Mr. Stoffler has not considered these issues in depth before proposing his new approach.

Let me underline the fact that there is no evidence that the UKMET office model is a superior regional model.  WRF has far more physics options and is much more widely tested at high resolution around the world.  UKMET Office global forecasts have slightly better verification scores in the Northern Hemisphere that the NOAA GFS, but these differences are small.   Furthermore, the NOAA GFS model is now undergoing rapid improvements (made possible by the new supercomputers NOAA is getting this year) and I suspect that by the end of 2016, the GFS will be as good, if not better, than UKMET.  Thus, the AF could well end up with an inferior global forecast.

But it is worse than that.   The UKMET office model is known to be difficult and unwieldy to use, and there will be a hugely expensive spin up at the AF to run this model and connect it to their production suite of products.  Resource demands in running a state of the science global model are huge. And as I have described in previous blogs, the U.S. has TOO MANY models running, resulting in division of effort and waste.  The AF is taking the wrong road.

But let's be honest here.  This situation is a warning to the National Weather Service and the U.S. weather modeling efforts---if the U.S. Air Force is making plans to use overseas modeling systems, this is not a good sign.

Major Impacts on WRF

Air Force funding has been critical for the viability of the national regional weather forecast system (WRF), the one used here at the University of Washington, by the way.   The AF has been the main Federal financial supporter of WRF.  The loss of AF funding will greatly undermine WRF and its future development (including the revolutionary global MPAS model that would be its successor).   WRF is the model used in many key forecasting systems in the U.S., such as the National Weather Service High Resolution Rapid Refresh system. The economic and scientific impacts of the AF action would be large and damaging to the U.S. weather prediction enterprise.


What needs to be done

The U.S. meteorological community and others need to speak loudly to Air Force management, the current administration, Congress, and others to stop this ill-advised AF action.  The damage to the U.S. weather prediction capacity and AF weather prediction will be substantial if the proposed plan is followed.  There is time to turn this around and restore a rational approach to weather prediction modeling the in the Air Force.   Here in Washington State, I hope our Senators, Patty Murray and Maria Cantwell, will intervene.


Sunday, April 19, 2015

Siberian Smoke Reaches the Northwest

Few things communicate the environmental interdependence of our planet better that the movement of Asian pollution across the huge Pacific Ocean and its impacts here in North America.

And we have had a good demonstration of this long-range transport during the past few days, as smoke from huge fires over southern Siberia  have wafted across the North Pacific, producing hazy skies and enhanced sunsets/sunrises over the U.S. West Coast and western Canada.

We don't think about it very much, but the air we breath in Seattle today was over Asia 3-7 days ago.

Yesterday morning , I was walking with a friend along the Sound and the reduced visibility of Rainier and other features was striking.   An image from the UW web cam yesterday afternoon illustrates this.  Sunrises and sunsets have been accentuated with enhanced red colors--a good sign of smoke.

Western Asia has been an environmental problem zone the past week.   The initiator of the problems was a strong low center that moved eastward over Siberia, producing strong winds over the region (see weather map with sea level pressure and 5000 ft  above sea level wind speeds  for 1200 UTC April 15th).  The colors show wind speed and greens are winds about 40 knots.


Some farmers in Siberia prepare their fields by burning debris from the previous year and unfortunately the winds caused the fires to burn out of control, causing a massive conflagration that has killed at least 30 people, destroyed thousands of homes, and created a huge smoke plume.


The same strong winds have picked up dust and sand in Mongolia and northern China, resulting in one of the worst dust /sand storms around Beijing in years.


NASA satellites have documented both the fires and the smoke/dust rising up over Asia and have tracked it crossing the Pacific.   This image from April 14th shows the fires and if you look closely you will see the smoke plumes (greyish shading in contrast to the clouds, which are more white).


Here are a sequence of NASA images showing clouds and the smoke (colored), starting over Asia and moving our way.  You can see the substantial value of NASA satellites that observe our atmosphere at many wavelengths, showing everything from clouds and precipitation particles to aerosols and pollution.





Not convinced of the Asian origin of our air the last few days?   Well, to confirm the above hypothesis I ran an air trajectory model (NOAA Hysplit) to see where the air over us come from.
Specifically, I found the origin of the air at 11 AM Saturday ending over Seattle at three levels: 1000, 2000, and 3000 meters above sea level (shown by red, blue, and green lines in the figure).  Our air came from Asia, with the air ending at 3000 meters above us (roughly 10,000 ft) starting OVER SOUTHERN SIBERIA.


Air quality data at the surface over our region has shown little impact, suggesting most of the Asian smoke has stayed aloft.


Friday, April 17, 2015

The Meteorology of the Solar Power Revolution

There is a quiet revolution in energy production that will change the lives of many:  the solar energy revolution.

With the cost of photovoltaic solar systems dropping rapidly, there has been a rapid expansion of solar power installations, both commercial and residential, around the U.S., with particularly rapid growth in California.

Consider the geographical distribution of the resource:  where are the best locations in the U.S. for solar power?

By considering both solar angle, cloudiness, and other factors,  NREL (National Renewable Energy Lab) has produced solar energy resource maps for the U.S.   Here is the annual average values (per day in kilowatt hours per square meter).   The southwest U.S. is the Saudi Arabia of solar energy, with the highest values stretching from western Texas to California.    It is really better than Saudi Arabia, since there is huge population hungry for energy  in the Southwest (e.g., Los Angeles, San Diego, Las Vegas, Phoenix, Tucson, etc.)  Lots of sun during the day, exactly when folks need it for air conditioning and their daily lives.
There are, of course, two main factors than produce this geographical distribution.  First, annual solar radiation increases towards the equator.  But more importantly there is the distribution of cloudiness with the desert SW have less clouds (see map)

For us here in the Northwest, there is substantial solar energy potential over eastern Washington and Oregon.  This is particularly true during the summer months when our region enjoys clear skies and LONG summer days.  To illustrate, here is the solar resource for July.  The Columbia Basin is world class, as good as California.

There is a factor that enhances the NW solar energy potential, making up a bit for the fact we are relatively far north:  our temperatures.    It turns out the photovoltaic cells are sensitive to temperature, with efficiency greater at COOLER temperatures.    Thus, high temperatures in the

desert southwest works against solar cell efficiency.  But cooler temperatures makes our solar panels more efficient, partially leveling the playing field for us a bit.

The amount of solar energy being produced today is far greater than many people think, particularly in California, the U.S. state with the most installed solar units.  Here is a plot of the renewable energy output for California yesterday (April 16, 2015).  Solar energy is the dominant source of renewable energy during the daytime hours.


But here is the amazing thing.  The next plot shows total energy production yesterday in CA from all sources.  Renewables (mainly solar) are roughly 25% of the total energy production during the day--and this does not include solar production at individual homes!


But what about here in cloudy Seattle?   It turns out that solar energy from photovoltaics can make sense for local residents, particularly with all the Federal, State, and local subsidies.   One of the faculty members in my department installed a solar system two years ago.  He finds that for the sunny six months of the year be pays nothing for electricity AND produces enough juice to charge his Chevy Volt for all his local driving.  His estimated payback period is 7 years.   Even without subsidies his solar array would make financial sense.  Electric cars are a perfect adjunct to solar energy, allowing excessive power to be stored in the car's batteries for transportation and other uses. Warm climates like the U.S. Southwest are also good since energy demand (for air conditioning) is closely related to solar output.

The U.S. is hardly tapping it potential for solar energy, and with supportive policies U.S. solar generation could easily be 10 times larger than today in ten years, supplying 10-15% of all U.S. electricity demand, and much more in the solar rich regions like the southwest U.S.  These are conservative numbers--I bet we could do much better.

There are several firms, with meteorological modeling and statistical expertise, that supply solar energy forecasts for industry and others.   One of the biggest is here in Seattle:  3-Tier/Vaisala:


In short, solar energy collection is growing rapidly today, but is only a shadow of what it could be, particularly since prices are dropping rapidly and the technology is progressively improving.

Wednesday, April 15, 2015

Northwest Snow Gods Are Kind and Cruel

Reputed to live high in the Olympic Mountains, our regional snow gods are playing games with us.

After a winter with marginal snow, the gods unleashed 1-2 feet above 4,000 feet in our mountains, as illustrated by the snow accumulations at Stevens Pass and Mt.Baker (see below)


With this additional snow, Stevens and Mt. Baker reopened for a few days.  You really have to respect the unflagging determination of the folks that operate the Mt. Baker and Stevens ski areas....they have been relentless in trying to give local skiers a chance on the slopes.

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 Today, the NW Avalanche Center produced the latest summary of the current state of the snowpack at local ski areas (see below).  The situation is a bit better than a month ago, with Hurricane Ridge at 14% of normal and Stevens at 33%.    The higher Paradise and Timberline sites are around 50% of normal.  Not great, but at least there is something up there again.

Why did we get some snow?   Because for practically the first time in the winter we have had some colder than normal air over us, associated with westerly winds pushing off of the Pacific (see upper level map for last Saturday when a lot of the snow fell).. But that is about to change as we switch to a


much warmer pattern, as a high-amplitude ridge builds up this weekend (see below).  Yes, the persistent West Coast ridge is back...and it should be around for a while.


The National Weather Service and Weather Channel forecasts for Seattle  (see below) shows temperatures rising into the 70s on Sunday through Tuesday.  Great for outdoor activities, but bad for snow...I suspect that will close out the ski season this winter.


With a persistent ridge in the West and trough in the east, the NOAA Climate Prediction Center is going for a familiar 6-10 day temperature forecast, with warm air in the west and colder temperatures in the east.  So if you want to go skiing here in the Northwest...better get up there tomorrow.


Monday, April 13, 2015

Media Miscommunication about the Blob

One of the most depressing things for scientists is to see the media misinform the public about an important issue.

During the past few days, an unfortunate example occurred regarding the warm water pool that formed over a year ago in the middle of the north Pacific, a.k.a., the blob.  Let me show how this communication failure occurred, with various media outlets messed things up in various ways.



The stimulant for the nationwide coverage of the Blob was a very nice paper published by Nick Bond (UW scientist and State Climatologist), Meghan Cronin, Howard Freeland, and Nathan Mantua in Geophysical Research Letters.

This publication described the origin of the Blob, showing that it was the result of persistent ridging (high pressure) over the Pacific.  The high pressure, and associated light winds, resulted in less vertical mixing of the upper layer of the ocean; with less mixing  of subsurface cold water to the surface.  Furthermore, the high pressure reduced horizontal movement of colder water from the north. Straightforward and convincing work.

The UW News and Information Office decided to spotlight this work in a press release, one that also
talked about a paper by Professor Dennis Hartmann: Pacific sea surface temperature and the 
winter of 2014.   This is another excellent paper and makes a convincing case that anomalous high 
pressure in the eastern Pacific and low pressure (troughing) in the eastern U.S. (which brought cold air to the eastern U.S.) was the result of warm, water in the subtropics (NOT THE BLOB).

Unfortunately, the UW press release misrepresented the facts. Clearly, the writer did not appreciate that the two papers were discussing two different areas of warm water (the blob in the midlatitudes and a second pool of high surface temperatures in the subtropics).    The title of the release was unclear (did linked  indicated a cause or just a correlation?)  and the first few paragraphs were explicitly wrong, suggesting that the "warm blob" was causing "weird" weather across the U.S.  




Let me be explicit what these papers DID say.  Dennis Hartmann's paper uses models to indicate that persistent warm water in the subtropics caused an anomalous "wave train" that altered the circulation over the eastern Pacific and North America, with high pressure over the eastern Pacific and troughing over the eastern U.S.   The Bond et al. paper showed how the anomalous high pressure produced the midlatitude warm water blob. 

The inaccurate press release then led to a media frenzy, with the story going viral.  And unfortunately, many of the media got it wrong.   

There were two failure modes.  In one, the headline was wrong, but the internal story was correct. Such a failure was found in the Seattle Times article (see below).    The text was written by Sandi Doughton, an excellent and careful science writer, while the headline was written by Seattle Times editorial staff.   Inaccurate, hyped headlines are common in the Seattle Times.  I can't tell you how many times exasperated reporters have complained to me about it.






In the second failure mode, the story itself was essentially flawed, with most claiming that the Blob off of western North America was the cause of the anomalous circulation (big ridge over West Coast, trough over the eastern U.S.).   (The truth:  the Blob was the RESULT of the anomalous circulations.)   That the Blob CAUSED the California drought or the cold wave in the eastern U.S. These deceptive stories were found in major outlets around the country, including the Washington Post, NBC News, and others.





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Take a look at a Weather Channel "science" page found here  Its lead sentence say is all wrong:
Scientists say a mass of warm water off the U.S. West Coast is to blame for the bizarre weather affecting the country. 

I could give you two dozen examples of essentially wrong stories about the Blob in major American news outlets during the past few days.  And this is only one story...many other stories are similarly confused or hyped.

How many ways can you say DEPRESSING?   Nearly every science story I have an intimate knowledge about has major errors.

Why is this happening?   I can offer several reasons:

  • University (and government) PR offices are desperate to secure media attention (get lots of "clicks") and are willing to hype stories to get it.   PR folks without science backgrounds often have inadequate time to get stories right..
  • Media outlets have hollowed out their science reporting staffs.
  • Reporters are writing stories without reading the papers they are supposedly describing.  Often they simply repeat or repackage (without checking) the press releases of universities and government agencies.
  • The war for clicks (and the ad revenue the results from them) has encouraged exaggerated headlines.
What can scientists do to get the straight story to the public?   One approach is to go direct though blogs, web pages, or direct interviews.   Another is to insist that they get to review all press releases from their organizations.  You can surely think of others.  But the problem is a serious one, with the public being given, and often believing, inaccurate information.




Saturday, April 11, 2015

The Atmospheric Spigot Turns on For the Pacific Northwest

Water worries for the Northwest continue to fade as a series of very wet systems hit the Northwest this weekend.

Friday afternoon brought an intense cold front, with bands of heavy showers over western Washington (see regional radar image at 5:51 PM Friday).  Yellow and orange indicate very heavy showers.


Here is the 24-h precipitation totals ending 8 AM today (Saturday).  Substantial amounts on the western sides of north Cascades and Olympics (around 1.5 inches), but the rain shadowing was impressive with only about .01 inch over the San Juan Islands--those folks live in Paradise.  Eastern Washington was dry.



After the front moves through, the upper atmosphere turns westerly, with a huge powerful jet bringing west-east flow over the entire eastern Pacific (see graphic for 11 PM Friday night at 500 hPa, about 18,000 ft, yellow colors are the strongest winds and winds are powerful to the height lines).  A powerful hose is aimed right at us.

Westerly flow produces strong uplift and precipitation on the western sides of our mountains, but lee rain shadows to the east of the mountain crests. And so the forecast show.  Here is the 72-h total precipitation ending 5 AM Monday.  1-3 inches in the mountains and the western slopes.  But bone dry in Yakima!

The air will be cool enough for substantial SNOW in the mountains--here is the 72-h snowfall total forecast by the UW WRF model.  Up to 2 feet in the WA Cascades and LOADS of snow around Whistler and the BC Cascades.  


All this is happening after Seattle Public Utilities have brought the city reservoirs to very high levels.  So Seattle's water situation looks extremely good.  

The long-range forecast for the subsequent 72h period keep Washington moderately wet but hits southern BC very hard, with 2-5 inches of precipitation (see first map below) and HUGE amounts of snow (see snowfall for that period in second map).  Even the north Cascades gets a piece of this.



Unfortunately the weather pattern is not favorable for arid California, but increasingly it looks like the Pacific Northwest will have adequate water supplies, even with a below normal snowpack.