Sunday, April 22, 2018

The Upcoming Heat Wave in the Pacific Northwest

During most years there is what I call a mid-spring heat wave, typically between mid-April through mid-May.

And we are going enjoy such a heat wave this week.  But why a mid-spring heat wave?

By mid-April, our sun is strong and the days are long....keep in mind that the sun's strength today is the same as August 20th.

But to get the heat we have to turn off our natural air conditioning...onshore flow off the cool Pacific.  And to get real warmth, some nice downslope flow down the western slopes of the Cascades, allowing air to warm by compression.

And there is a way to do this...have high pressure build to the east of the Cascades....and that is exactly what will happen this week.

The fact we often get heat waves in April and May is obvious by looking at a climatological plot of extreme daily temperatures at Sea-Tac Airport (yellow line below).  Temperatures have zoomed up to 80 in April, 80s (even low 90s) during May.

At the UW we run a high-resolution ensemble of 15 forecasts to get a handle on the uncertainties in the forecast.    Here is prediction for surface air temperature from last night's run.  The black is the ensemble average...normally a very good forecast.   Nearly right-on for today (high got to 59F).  Tomorrow's model forecast bringa Sea-Tac to 70F...roughly a ten-degree hike.  And 75F on Tuesday.

Want more assurance of the warmth?  Here is the latest output of the National Weather Service Short-Range Ensemble System (SREF). 70F tomorrow, 75F on Tuesday and a bit warmer on Wednesday, although you will notice that there is increasing uncertainty (the forecasts vary more).

 You really want to enjoy the warmth before it happens?  Let me show you the surface temperature forecast maps from the UW system.

First, the forecast for 5 PM tomorrow (Monday).  68-72F in much of western Washington.  72-76F around Portland and over the western foothills of the Cascades.

Tuesday at 5 PM.  Amazing. Upper 70s from Seattle to Portland.  Even along the coast, thanks to the offshore flow.

Wednesday at 5 PM.  A bit cooler over Seattle, but much warmer around the Columbia Basin of eastern Washington.  This is a sign that the high pressure is moving eastward.

Enjoy the warmth...after a cool, wet few weeks it will be nice to experience the spring-time lushness of the Northwest under sunny skies and perfect temperatures. 

There is one problem, though....the pollen count is high right now and according to will get higher with all this warmth (see below).   Sorry...

Saturday, April 21, 2018

The Connection Between Heavy Rainfall in Kauai and Washington State Last Weekend

Last weekend brought catastrophic rain to Kauai, resulting in floods and landslides.  And last Saturday, portions of Washington State were inundated with heavy rain that brought localized flooding.

The interesting thing:  they were directly connected.  Let me explain.

Kauai by any measure is a wet place. But it is also a place of great precipitation contrasts. These contrasts are directly related to the terrain, with the two highest peaks being Kawaikini (5243 ft) and Mt. Waialeale (about 5150 ft.).   Moist tropical air ascending this terrain results in huge amounts of precipitation.

The annual precipitation illustrates this (below), with much of the higher terrain soaked by over 150 inches a year. In fact, the heaviest average annual precipitation in the U.S. occurs at Mt. Waialeale with 460 inches a year-- much more than our Olympics, which enjoy the record for the highest total in the rest of the U.S. (about 150-180 inches a year on the windward slopes).  The northern/northeastern side of Hawaii tends to have heavy precipitation since it faces the incoming trade winds, while the southeastern side (e.g, Poipu) is relatively arid, with only 20-40 inches a year.  Most vacationers head to the south side of the island for obvious reasons.

Last weekend there were unimaginable amounts of precipitation hitting Kauai. Below are the 48-h totals for the 48-hour period ending at 6 PM HST on April 15, 2018 provided by the National Weather Service. All values are in inches.
Wainiha and Hanalei on the north side got huge amounts (28-32 inches). No wonder there was massive flooding. But Kalaheo on the southern side only had 1.55 inches (which is still a significant amount of rain)

Wainiha : 32.35 
Hanalei : 28.41 
Mount Waialeale : 22.34 
Princeville Airport : 14.60 
Kilohana : 13.19 
North Wailua Ditch : 10.62 
Kapahi : 10.12 
Wailua : 8.21 
Lihue Variety Station : 3.36 
Anahola : 3.20 
 Lihue Airport : 1.92 
 Kalaheo : 1.55 

A map of the 24h amount ending 9 AM HST April 15th shows the amazing contrasts.  Keep this in mind when you consider a vacation in Kauai.

Back to the connection with Washington precipitation on Saturday.   As noted in an earlier blog, an atmospheric river brought heavy precipitation to our area that day, with up to 2 inches in Seattle and 3-6 inches in the mountains.

It turns out that there was a direct connection between the plume of moisture hitting Washington State and the moisture inundating Kauai.   The UW model forecast for the vertical total of precipitation at 5 AM Saturday (PDT) shows this.

And a satellite-based measurement of moisture for the 12h ending 5 AM (PDT) Saturday, shows the connection, with Kauai getting hit by MUCH larger values (orange colors) than we endured.
 And the connection was quite clear in satellite-based water vapor imagery, with the lighter colors indicating more water vapor in the upper troposphere.

But what caused the connection in moisture?  An upper-level (500 hPa) map at 5 PM Friday (0000 UTC 14 April) shows an extensive upper level trough that extended back to Hawaii.  The strong southwesterly flow associated with the trough (where the lines are close together) moved moisture into our area, while the trough extension over Hawaii contributed to vertical motion and precipitation there..

A surface map 12-h later (5 AM our time) shows a front approaching our coast, while a trough (area of low pressure indicated by the dashed lines) extended back towards Hawaii,with moderate northeasterly flow that rose up the northeast slopes of Kauai.

Hawaii and the Northwest have a lot of weather connections..... atmospheric rivers (which we call pineapple expresses) are, of course, one.   But there is a lot more, including the ocean currents which, move water from off our coast to Hawaii.

And those currents will assist a brave UW student in rowing from the West Coast to Hawaii in June.

Announcement:  The Northwest Weather Workshop is on April 27-28

The NW Weather Workshop is the big annual meeting for those interested in Northwest meteorology.  This year we will have a major session on the meteorology of NW wildfires and others on other aspects of our regional weather.  The gathering takes place at the NOAA facility in Seattle.  To view the agenda and to register, go to the meeting website.  The workshop is open to everyone, but registration is required.

Thursday, April 19, 2018

Dense Fog: Unusual This Time of the Year

This morning brought fairly dense fog to portions of Seattle near Lake Washington and in some river valleys around the western side of the State.  The fog was beautifully illuminated this morning around 7 AM in the view looking north from the Space Needle PanoCam

And the view southeastward towards Mount Rainier was impressive as well.

The fog was apparent is the visible satellite image at 7 AM, with some of the river valleys of SW Washington in fog.

It  turns out the dense fog is relatively unusual this time of the year in Washington State.    I can show this using the following graph from my NW Weather book. Here in Seattle (red color) fog reaches the minimum number of days per year from April through June.  Spring is a low time for fog in most locations of our region.  Fall is the big fog season.

But why is Spring so bad for fog?  For several reasons.

First, most of our fog is radiation fog, which develops over long nights as the earth radiates infrared energy to space.    Our nights are getting MUCH shorter now, so much less time for the cooling to occur (remember our day-night periods today are the same as around August 23).

Second, fog likes stable conditions that does not produce a lot of vertical mixing.  Such mixing is bad for fog, since the cooling at the surface gets spread over too much air in the vertical. Stable conditions occur when temperatures don't decrease rapidly with height.  The opposite is true in Spring...the sun is fairly strong, causing the surface to warm, but the air is still cool aloft. Not stable and bad for fog.

Third, in spring around here we still have a lot of clouds and clouds slow up the radiational cooling from the surface. 

Fourth, rain is generally letting up in Spring and rain helps moisten the surface and lower atmosphere...which is good for fog.

Why fog today?  We had lots of rain recently so the lower atmosphere was moist.   And high pressure moved in late yesterday, which helped make the atmosphere more stable and lessened the amount of clouds aloft. 

Can our models forecast fog?   They can, but there skill is not great.  Fog plays into almost all our modeling weaknesses.   Here is the 14 hour forecast for low clouds valid at 7 AM from the UW WRF model.  Right idea, but somewhat too much fog/low clouds around Puget Sound.

And now the big news....a major warm up will occur early next week, with highs getting into the upper 60s on Monday and Tuesday.  And pretty decent the rest of the week.  More on the "big heat" in my next blog.

Tuesday, April 17, 2018

The Carbon Fee Initiative (1631) Has Major Problems: Let's Try Something Better

This fall, voters in Washington State will consider an initiative (1631) that, if passed, would put a fee on carbon and use the funds to "reduce pollution, promote renewable energy, and address climate change impacts."  Superficially it sounds good, but underneath the hood there are very serious problems.

In this blog, I will analyze Initiative 1631, note some its major deficiencies, and suggest a far better approach (a revenue-neutral carbon tax that would improve Washington's regressive tax structure).

As I described in my previous blog, I am a strong believer in carbon taxes and was an enthusiastic supporter of the defeated Initiative 732.   Mankind is doing too little to slow carbon emissions into the atmosphere, and a well-designed carbon tax or fee can use the free market to effectively respond to the problem.  Economists of all political backgrounds acknowledge the power of taxing what you don't want (in this case emissions of carbon) in encouraging people to make different choices.  Like driving smaller cars or switching to electric vehicles.

But Initiative 1631, whose goal is to initiate a carbon fee in Washington State, is deeply flawed and poorly constructed, and I believe destined for certain and dramatic defeat.

The Essentials

Initiative 1631 would establish a carbon fee that would slowly increase over time.  Unlike Initiative 732, it would not be revenue neutral, but would use the proceeds of the fee to support climate justice, renewable energy, retraining, and other activities related to global warming impacts.  
The Problems

There are so many serious deficiencies with this initiative, one hardly knows where to begin.

1.  How the money will be spent is vague

There are really no clear guidelines on how the money will be spent.  15%  should address the "energy burden" of poor households, 10% goes to the Tribes, 35% to environmental justice, $50 million to help displaced fossil-fuel workers, and the rest to vague goals in supporting renewables and clean energy.

Decision authority on how the money will be spent will be given to a 15-member board appointed by the Governor to four-year terms, and would include one tribal representative, one representative of vulnerable populations/health action areas, and the six co-chairs of a collection of panels.   So basically a group of liberal activists, appointed by a Democratic governor will make the decisions.

There is no strategic plan, no requirements for technical knowledge, and a guarantee the spending will be highly political.  Not only is such a group practically guaranteed to spend the funds unwisely, but such a plan would certainly lose the support of moderates and Republicans. 

Most folks are not willing to spend money when they don't know what they will get.  That is the problem of I-1631.  Can you imagine if the bill had specified real, tangible benefits?   Such as supporting the rapid build out of rail from Seattle to its eastern/northern suburbs?

2.   The Initiative Would Make Washington State's Regressive Tax Structure Even Worse

Whether the money comes from a tax or "fee", the effect is the same... to make the cost of carbon fuels more expensive. Money people will have to pay out.  Unlike I-732, the proposed initiative will not return the funds to taxpayers, but use the funds for a wide range of unspecified activities that are somewhat connected to climate change in the minds of the oversight board.   

The financial impacts of I1631 are clear:  this is essentially a new tax that is not based on income.   It will substantially raise the tax burden on everyone, including low-income folks, who are just as dependent on cars and trucks as anyone.  Thus, just like the sales tax,  it will be highly regressive, with the poor paying a higher percentage than their richer neighbors.  The media has headlined our regressive tax structure in Washington State.  I-1631 will make it much worse.

3.  I-1631 is Highly Partisan

To pass in Washington State and to serve as a blueprint for action for other states, any carbon tax or fee must have bipartisan support.  A revenue-neutral carbon tax could garner support from both sides of the aisle, as was true for for I-732.  For example, ast year, major Republican figures came out in support of a national revenue-neutral carbon tax.

Unfortunately, it would be hard to design an approach more likely to turn off Republican and independent voters than I-1631.  Not only is it not revenue neutral, but the funds are hardwired in the direction of Democratic supporters (labor, the tribes, minority and low-income "climate justice" groups).   Even worse, the control of the funds is put in the hands of an oversight committee selected by a Democratic governor.

I-1631 is designed to reject the moderate and conservative electorate (e.g., nearly all of eastern Washington and Vancouver, WA) and will not be suitable to serve as an example to the nation.

4.  I-1631 Gives Too Many Exemptions and to the Wrong Groups

To garner support, I-1631 gives exemptions to many business groups.  For example, it exempts local power companies (e.g., PSE), which is a total mistake since it represents a major user of fossil fuels.  The initiative also exempts coal-burning facilities (e.g., the Centralia coal plant), that offering perverse incentives to burn more coal, one of the dirtiest fuels.  And there a dozens more exemptions that I won't list.   I-732 did not do the exemption thing, but removed the B & O taxes to help businesses.

5.  I-1631 Starts Off With Too Little Impact

This initiative begin with a fee of $15 per ton, which would increase gas prices  by about 14 cents a gallon.   Not enough to make folks alter their lifestyle or the vehicles they purchase. Everything we know about climate change tells us that a large and immediate reduction is needed.  I-1631 starts weak, particularly compared to I-732, which began at $ 25 a ton of carbon emissions.

I could go further about the problems with I-1631, but you get the point:  this is a hopelessly flawed initiative that not only won't effectively address climate change in our state and would waste huge sums of money, but it will needlessly politicize what should be a bipartisan effort.   I should note that the key supporters of I-1631, The Alliance for Jobs and Clean Energy, the labor unions, and the Sierra Club actively opposed the revenue-neutral carbon tax (I-732).  

Why?  Clearly, because they did not gain access to the money.  With I-1691 they would.

A Revenue-Neutral Approach:  Far Superior By Any Measure

Now imagine a different approach, one in which a sufficiently large carbon tax is applied to encourage folks to reduce their carbon emissions.  An approach that would refund ALL the money back to the people so they are not taking a financial hit.  A revenue-neutral approach.

But it could be better than that, we can refund the carbon tax in a way that provides preferential relief to low-income people.  There are many ways to do this.  We might reduce the State sales tax by 1-2%, lessening the most regressive tax we have.   Or we could give everyone back the same carbon tax dividend, which would preferentially help low income folks that can't afford the carbon rich lifestyle of the wealthy.   Some funds could go into a low-income tax credit, as done in I-732.   

Our state has the most regressive tax structure in the nation.  The proper use of a carbon tax could help improve this dismal situation.

But it is even better than that.  The carbon tax could be bipartisan, bringing the State together to begin to address the threat of anthropogenic global warming.  And such a carbon tax could have legs, with the ability to spred to red and blue states around the union.

The question is not whether I-1631 will pass.    It won't.  Can you image folks taxing themselves to contribute to such a poorly designed and vague plan?  Will low-income people willingly tax themselves hundreds of dollars a year to support the vague goals of some environmental activists?  You know the answer.

The real question is what happens after I-1631 fails.  Will the environmental left that killed I-732 decide to drop their financial demands and join in a bipartisan effort to deal with carbon emissions without social engineering and giveaways to their constituencies?    We will see.  

Climate change forced by increasing greenhouse gases is too serious an issue to waste time and effort, which is exactly what 1631 will do.


Announcement:  The Northwest Weather Workshop is on April 27-28

The NW Weather Workshop is the big annual meeting for those interested in Northwest meteorology.  This year we will have a major session on the meteorology of NW wildfires and others on other aspects of our regional weather.  The gathering takes place at the NOAA facility in Seattle.  To view the agenda and to register, go to the meeting website.  The workshop is open to everyone, but registration is required.

Sunday, April 15, 2018

Localized Deluge

News flash:  It is 9 AM on Sunday and it should be generally dry for the next 4-5 hours.  Immediate response necessary (e.g., go outside).    There are a few residual showers, some of which are producing rainbows (see 9AM Seattle SpaceNeedle panocam).  Note the blue skies.

Yesterday was an amazingly wet day for April, and a "highlight" of one of the wettest Aprils on record.   A number of locations (like Seattle) had their wettest April 14th on record and April is now the 4th wettest on record and WE ARE ONLY THROUGH HALF THE MONTH.

The rain distribution yesterday was interesting, with the heaviest precipitation found in a southwest-northeast band from SW Washington across Seattle and into the central Cascades. 

Here are the 24h totals ending 11 PM Saturday (only showing the locations with at least 1.5 inches).   1-5-2 inches over Seattle, but 3-5 inches over SW Washington and nearly 5 inches on the western side of the Cascades NE of Seattle.  8 inches near Mt. Rainier.

The heaviest rain was during the late afternoon and early evening when local streets started to flood.

A radar-based estimate of 48-h rainfall ending 11 PM Saturday show the band of heavy precipitation across central Puget Sound, with 2-4 inches being prevalent.  And you will also notice the rainshadow over NW Washington--those lucky folks from Sequim and Port Townsend to Bellingham.

What was going on?   A relatively narrow atmospheric river of moisture that sat over us for over 12 hours.    You can see the culprit in an infrared satellite picture at 11 AM Saturday (below).

A plot of the moisture content of the atmosphere at 11 AM yesterday shows the feature, with the orange and red colors indicating high values of total moisture in the atmosphere.  Heading right towards us.

Another very useful tool can be created by multiplying the moisture content by the wind...something called Integrated Vapor Transport (IVT).   That is what really controls how much rain we get on our mountains.  IVT at the same time (11 AM) as above  shows significant values moving off the Pacific, with an configuration matching the heavy rainfall.

The forecast for the next 24 hours?  Good news for sodden Washington, bad news for Oregon.  The accumulation from 5 AM Sunday to 5 AM Monday indicates lots of rain in Oregon and northern CA, which is excellent--they need more water down there.  Washington has enough.  More than enough. Our snowpack is above normal.  Our reservoirs are full.  Our rivers are running high.  Our soil moisture is high.

I am heading outside for a run with my dog while I have a chance.

Friday, April 13, 2018

Is this an unusually poor spring in the Pacific Northwest?

The complaints are coming in. 

I can't tell you how many people have told me that this spring is unusually bad.  My son, a Northwest native, is threatening to move to southern California because of the weather.

Green slime is spreading on my deck.

So have we really been cooler and wetter than normal?  How bad is it really?

Ok, let's check the facts.    We can start by look at the difference from normal of the average temperatures over Washington State for roughly the last month.  Most of the Washington State is green, blue, or purple--the colors indicating below normal temperatures.  The above normal temperatures at Yakima I would ignore, there is something wrong with  thesensor.  Slightly warmer than normal east of the Olympics.

  So yes, the state has been a few degrees below normal.  Looking at Seattle's temperatures for the last four weeks (red lines), compared to the normal highs and lows  (purple and cyan lines), we can see that  things weren't that unusual, with temperatures rising above and below normal. 
Yakima temperatures look pretty normal to me.
Spokane does appear to be significantly below normal for the past month.
Bottom line:  the complainers probably have a point about it being cooler than normal, something that is typical of springs during La Nina years.  But around Seattle, just a little below normal.

What about precipitation?

A much more complex story.  Here is the difference of observed precipitation from normal for approximately the last four weeks.  Wetter than normal along the western slopes of the Cascades and much of eastern Washington, but way drier than normal to the east of the Olympics and in locations just to the east of the Cascade crest.

I bet I know what is going on. During the last month we had an unusual number of days with westerly winds (from the west), which resulted in a strong rain shadow to the lee (east) of the Olympics as the air descends down towards Puget Sound.  And persistent westerly flow explains the heavier rain on the windward (west facing) side of the Cascades. 

Here is the cumulative precipitation at Sea-Tac compared to normal for the past month... the observed (purple) was a bit more than normal  (cyan).
Yakima and Spokane?  Considerably more than normal, at least percentage wise (they don't get that much there).
What you really want to know is the future, right?   Well, there is plenty of cool, showery weather through the weekend.

The next week will make ducks very, very happy.   Here is the forecast accumulated precipitation through next Thursday at 5 PM.  Large amounts (5-10 inches in the Olympics and Cascades) and  even substantial precipitation down into California.  And freezing levels will be low enough for substantial snow from BC to the Sierra Nevada. 

I think I will see if my son can get a ticket for California for me as well.

Wednesday, April 11, 2018

A Good Example of Why Need a Weather Radar Along the Oregon Coast--AND--The Northwest Weather Workshop

The value of having a radar on the Washington coast has been so clear since it was installed in 2011, that the lack of radar coverage over a large portion of the Oregon Coast and western Oregon is even more obvious.  And today provides a great example of the problem.

This morning at 11 AM, the infrared satellite imagery showed a front approaching the Northwest coast.   But where was it raining?

The UW WRF model forecast for precipitation for the 3-h precipitation total ending 11 AM predicted a continuous band of rain along the coast.  But was that right?

Well, to tell that you either need a LOT of rain gauges or good weather radar coverage.  The National Weather Service radar locations and coverage at 10,000 ft above ground level  is shown below.  This is optimistic and coverage can be much worse below 10,000 ft where there is blockage by terrain.  

In any case, Oregon is a radar coverage disaster, with poor coverage over the central and southern coastal zone and little coverage over much of eastern Oregon.

Here is the actual weather radar imagery at 11 AM from all available National Weather Service radars.  No precipitation over 2/3rds of the Oregon coast and offshore.   It was raining there, but it was invisible to the Portland and northern CA radars.  They desperately need a radar on the central Oregon coaast.

This problem doesn't seem to being considered seriously by the National Weather Service.   As we learned in Washington State, the National Weather Service will not address such problems without intense pressure from local citizens and their congressional representatives.  Here in Washington State, Senator Cantwell, with the help of Senator Murray, did a lot of the heavy lifting in DC.

The Northwest Weather Workshop

     People ask me all the time about whether there are any local meetings for those who enjoy learning mre about Northwest weather.  The answer is a big yes!  The Northwest Weather Workshop held in Seattle each spring.   

This year, the meeting will take place at the NOAA Sand Point facility in Seattle on April 27-28th. 

Two sessions will deal with the meteorology of Northwest wildfires and on Friday we will also have session on the results of the OLYMPEX field program (studied precipitation processes over that mountain barrier).  Other sessions will deal with the latest on NW weather modeling, communication of the risk for extreme events, reviews of major weather events of the past year, studies on NW climate, and much more.  The banquet on Friday night will include an excellent speaker, Professor Dan Jaffe of UW Bothell, who will describe some of the air quality impacts of wildfires.

To see the agenda, go to the official website and registration portal :

This meeting is open to everyone, and I suspect that even complete layfolk will get a lot out of 90% of the talks.  But keep in mind that  YOU MUST REGISTER IN ADVANCE TO ATTEND THE EVENT, which you can do at the above link.  There is a modest registration fee that includes snacks and lunch on Saturday.  If someone can't afford the registration fee, we can work something out.

Anyway, it should be a great meeting and everyone is invited, but NOAA security prevents anyone who has not registered from gaining entry.