Tuesday, October 27, 2020

The Election Day Weather Forecast: Who Will it Favor?

 I got a call today from a political science professor from California:  he wanted to know how to get reliable weather forecast information for next week because weather can favor one party over another.

I helped him, but this got me thinking about the weather on election day, particularly since we are now close enough in time to have some skill.

I was familiar with a number of studies that have been done on this subject, and their suggestion that bad weather favors Republicans (see an example below).


So what do the latest and best model forecasts predict for election day?

Since my blog readers deserve the best, I examined the world-leading guidance from the European Center model.

The forecast for election day over much of the U.S. is extreme..... extremely pleasant, with minimal storminess and precipitation.

To give you the best possible forecast let's examine the European Center ensemble model predictions in which they run their model 51 times, each slightly differently,  The average or mean of  these ensemble forecasts is usually a good prediction.

The ensemble-mean upper level (500 hPa, about 18,000 ft) weather map for 11 AM PDT shows a HUGE area of high heights/pressures dominating nearly the entire U.S., while a trough of low pressure/height is offshore.    Such a pattern will bring warmer than normal and dry condition for the western two-thirds of the U.S.


To show his, there are the temperatures forecast for the same time. Toasty in California, the southwest, the central and southern Plains states, the Gulf Coast and Florida.  The only locations that will be below freezing will be northern New England and New York.


Precipitation that day?  Almost nothing except for a few sprinkles in New England.  Even Seattle will be dry!
Considering this forecast, the classical papers, such as the one noted above, would suggest an enhancement of Democratic voting.

But I suspect there are some surprises ahead.   How will the COVID pandemic and huge numbers of mail-in ballots change the story?  The percentage voting on election day will be much smaller than normal. 

Trump supporters are probably different that the Republican voters of 20-30 years ago.  And can one really trust telephone-based polling?  Many people are solely using smartphones and conservative voters may well be fearful of expressing their honest views to someone that calls their home out of the blue.

One thing is for certain:  the weather this weekend looks quite pleasant here in the Northwest--a perfect time enjoy the fall colors.  A pleasant way to forget the election for a few hours.

Picture courtesy of Rachel Samanyi

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My blog on KNKX and the Undermining of American Freedom is found hereAn important story about Matt Martinez, Director of Content of KNKX, is found here.







Sunday, October 25, 2020

Frost, Record-Breaking Cold Temperatures, and Strange Weather Features

Cold air with snow and record-breaking cold temperatures moved in Saturday morning, with some odd weather features thrown in.  And even an early snow record in Spokane.

Snow Spokane on Saturday, 
Picture courtesy of u/VeeMeeVee

Temperatures this (Sunday) morning dropped to below freezing over both eastern Washington and much of the west--the first frost of the season for much of western Washington.   

Take a look at this morning's minimum temperatures (see below, click on image to expand).   Lots of below freezing temps in the west, but eastern WA really impresses, with cold valley sites getting into the single digits.


If you ever want to appreciate the cold-blocking capabilities of the Rocky Mountains, examine a broader plot of last night's lows (see below).  Below-zero temperatures all  over western Montana.  The coldest air of the continental interior is blocked by the Rockies, and eastern Washington gets the warmed over cold leftovers.   Western Washington, protected by the Cascades gets the tepid remains of eastern Washington's cold meal.  A better stop this metaphor before it gets me into trouble.


Records-galore for cold and snow were broken during last 48h.   For example:
  • Spokane had 7 inches of snow on the ground Saturday morning, the snowiest October day in their long 135 year historical record.
  • Spokane's maximum temperature of 31° F Saturday was the earliest subfreezing maximum temperature in the 135 year historical record.
  • -10 F at Cut Bank MT broke a daily record which had stood for 101 years.
  • -13 F at Puntzi Mtn Airfield in BC appears to be an October record low temperature:
  • A number of locations in the region tied or beat their daily record low temperatures for the date.
The visible satellite pictures had had a number of interesting features. The snow across eastern Washington is clearly evident (blue arrow) in the imagery today and you can also view the considerable snow over the north Cascades.


Stranger perhaps is the thin tendril of clouds that extended westward from the Olympic Peninsula coast on Saturday and then swung to the south and southeast offshore (see below).   This feature resulted from the easterly offshore flow, with northeasterly and southeasterly air flows (blue arrows) converging offshore and producing upward motion and that interesting cloud line.


The National Snow Analysis shows a big increase during the last week (left image is today, right image on October 18th).


And we are way ahead of last year at the same time (see below)

If you want to see an image that is a bit deceptive but a lot of fun, below is the current percentage of normal snowpack from the US Snotel network:  TWO THOUSAND PERCENT OF NORMAL over NE Washington and nearly 1000% of normal over the north Cascades.  Values that might cause inveterate skiers to run for their equipment!   But this early in the season, such percentages mean little, as do the crazy low values we observed in late spring.

Expect dry and moderating weather during the next few days.
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My blog on KNKX and the Undermining of American Freedom is found hereAn important story about Matt Martinez, Director of Content of KNKX, is found here.


Friday, October 23, 2020

New Podcast: Cold, Wind, and Snow this Weekend, Plus the Secret of Western Washington Snow Events

Cold, Wind, and Snow this Weekend, Plus the Secret of Western Washington Snow Events


Click the play button to listen

Episode Description


In this episode, I talk about the active weather that we will experience this weekend, including strong winds, mountain and eastern Washington snow, as well as cold temperatures.  The weather will be surprising  to many.  And in the second segment, I will tell you why it is so hard to get snow in western Washington and will reveal the rare weather situation that allows snow to reach sea level west of the Cascade crest.   All Seattle mayors should listen to this podcast!

Want to support the podcast? Click the Patreon box below.  I will be hosting a zoom session for Patreon supporters at 10 AM PDT Saturday to answer questions and to interact on all things weather and climate. 



Stream my podcast from your favorite services:


My blog on KNKX and the Undermining of American Freedom is found hereAn important story about Matt Martinez, Director of Content of KNKX, is found here.


Thursday, October 22, 2020

Strong Winds, Cold Air and Mountain Snows Ahead

 Note: my new podcast on Wind, Cold and Snow will be out tomorrow morning
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The weather is about to get MUCH more active in our region, with the approach of a potent disturbance from the northwest, the invasion of frigid air from northern Canada, and the rapid increase in winds over Northwest Washington and the coast to 50-60 mph in places.  Even central Puget Sound will get a good taste of this wintry Zephyr.

The latest infrared satellite image shows a large area of clouds and precipitation approaching our region from the Northwest (see below).

This impressive feature is the result of a strong upper-level trough (area of low pressure) that is moving southeastward on the west side of large upper level ridge of high pressure over the eastern Pacific.  This trough will be approaching Washington State tomorrow afternoon (see upper level map at 2 PM tomorrow below).  Changes in the position of this trough (too far inland) now make it unlikely we will see snowflakes near sea level...but it will still bring a lot of weather action.

The surface reflection of the upper level trough...a small but potent low pressure system will move down the coast tomorrow (see the sea level pressure map at 11 AM tomorrow morning, solid lines are sea level pressure, colors are temperature, blue is cold).  This will bring strong winds to the coast and northwest Washington.


Below are the predicted gusts at that time:  some locations could see gusts to 40 mph or more.

But that is just the first stage in the upcoming weather adventure!

Twelve hours later (11 PM Friday), the low center will be crossing the southern Cascades and cold air will surge to the Canadian border, with some of it pushing into eastern Washington and Montana.  A huge pressure gradient (difference) will accompany the cold air (lots of pressure lines, also known as isobars).  In Montana the conditions will be severe.


Strong northeasterly winds will starting pushing through the Fraser River Valley and into Northwest Washington, something illustrated by the maximum gusts predicted by the UW/Seattle City Light WindWatch system (below) at 11 PM Friday.  Some gusts will push 40-50 mph and northern Puget Sound will get some of the winds as well.

By 5 PM on Saturday, eastern WA will be in the chiller, with cold accompanied by strong northerly winds.    The difference in pressure will build across the Cascades.  That is going to be important.


By 2 AM on Sunday, strong winds will continue to exit the Fraser River Valley and push out the Strait of Juan de Fuca, but they will joined by powerful finds moving across the Stampede Gap in the central Cascades that will accelerate down to Enumclaw, Black Diamond and out to Tacoma...and even the coast.
And did I mention snow?  With the upper level trough providing upward vertical motion and easterly flow providing more uplift on the northeastern slopes of the Cascades, there will be as much as a foot over and to the east of the crest of north Cascades.  A few flurries might reach sea level near Vancouver due to the cold Fraser outflow.  Snow will greatly lessen south of roughly Snoqualmie Pass.


Beyond snow, the accumulated precipitation  through Saturday morning at 5 PM (below) shows that there will be wet conditions in the Cascades down to southern Oregon (good for ending the fires)...but not that much over the Willamette Valley and Puget Sound, which will be rainshadowed by the coastal mountains and the Olympics. 


Precipitation will be over on Saturday morning and expect cool, blustery condition with lots of sun over the weekend.  Easterly flow will dominate and that usually brings dry conditions west of the Cascade crest.  You will sunblock and a jacket. There will certainly be power outages over NW Washington and around Enumclaw and vicinity.   Sunday morning will be particularly cold, with freezing temperatures over the region.

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Stream my podcast from your favorite services:


My blog on KNKX and the Undermining of American Freedom is found hereAn extraordinary story about Matt Martinez, Director of Content of KNKX, is found here.

Tuesday, October 20, 2020

Lowland Snow and Bountiful Mountain Snows: Is this Really Mid-October?

If this were December or January I would be looking for my snow shovel, bag of deicer,  and windshield scraper.

A favorable weather pattern for lowland snow will be in place on Friday, but this IS mid-October, with the ground and atmosphere still relatively warm from summer heating.

Not quite this bad.  
Picture by cheukiecfu

But if you believe the models, some folks over Northwest Washington will see snowflakes on Friday and bountiful snow will hit the Cascades and eastern Washington.

Let me show the latest forecast maps....you will be looking for a hot chocolate and a wool cap before I am finished.

Tomorrow (Wednesday) will give the mountains a small taste of the upcoming white treat, with a ridge of high pressure/heights offshore and a trough of lower pressure moving into the northwest (see upper level map below).  The result will

be some light snow in the Cascades, with as much as 8 inches at higher elevations.

Doesn't excite you?  Just wait. 

Below is the 24-h snowfall forecast ending 5 PM Friday for the UW high resolution WRF forecasting system.  

Wow.  8-12 inches over the Cascades and Olympics, bountiful snow over much of eastern Washington, and even snow at sea level north of Bellingham.  High temperatures for Friday will not get out of the 40s.


Some model forecasts are even more aggressive with lowland snow.  The latest European Center snow prediction for the same period even brings some snow to Everett (see below).

The sea level pressure pattern forecast for Friday is classic for Puget Sound snow.  Below is the sea level pressure forecast (solid lines) for 5 PM Friday.  Surface winds are shown as are low-level temperatures (purple is coldest, followed by blue and white).

A favorable (for snow) set up, with low pressure centered over southwest WA, and a large north-south pressure difference over western WA, which will bring in cool air from BC.   Not quite perfect for Seattle snow ... having a stronger low on the coast and colder sir in BC would be better.... but who is going to complain in October?   A very good pattern for snow east of the Cascade crest.


Early next week the upper-level ridge will strengthen and extend towards the coast, and the trough will push southward towards Arizona. (see upper level map for Tuesday at 5 PM).  Expect rapid warming and snow melt here in Washington State.


But there is something very ominous in this evolution.  Cold air and associated high pressure will move into the intermountain West and a strong pressure gradient will form over the Sierra Nevada (see surface pressure map, with low level temperatures for 11 AM Monday).  Such strong pressure differences could drive powerful winds that might initiate or rev up wildfires in CA.  Will have to watch this.



Finally, what was the earliest major snowfall at Sea Tac?    It was October 27, 1971 when 2 inches fell.  We won't beat on Friday.

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Stream my podcast from your favorite services:


My blog on KNKX and the Undermining of American Freedom is found hereAn extraordinary story about Matt Martinez, Director of Content of KNKX, is found here.









Sunday, October 18, 2020

What Will Northwest Weather and Climate Be Like in 2050?

The future of Northwest climate is frequently discussed and debated these days.

Knowing the future climate is very important, because we can take steps to adapt to climate change, saving lives and property. And the threat of unpleasant consequences can motivate society to take steps to reduce carbon emissions into the atmosphere and increase carbon storage in the ground.

A number of politicians have made climate change a centerpiece of their political platforms, and a range of natural disasters (such as wildfires, drought, and storms) have been blamed on increasing CO2 and other greenhouse gases. A free-for-all of name calling has followed this topic with terms such as "denier", "alarmist", and "warmest" representing just a few.

A Time Machine

Climate change has become such an issue of contention, that activist groups have pushed to remove radio commentators that don't follow their line (e.g., Seattle350 pushing KNKX to remove a certain meteorologist).  It has become an issue of almost religious intensity to some with "right thinking" on the topic becoming an important way to demonstrate that one is a true "progressive."

So let's  clear the air a bit now.  I will show you the gold standard of projections of what will occur here in the Northwest over the next three decades due to increasing greenhouse gases.   

It is a time scale that is short enough that I believe we can have great insights into what weather/climate conditions in the Northwest will be like if CO2 continues to rise.

Each of you can consider the projections and make your own judgement whether it is an "existential" threat, a serious threat, an inconvenience, or an improvement over our current climate.  You decide.

The Gold Standard of Regional Climate Projections

My group (particularly Richard Steed and Jeff Baars) in concert with Professor Eric Salathe of UW Bothell has been working on the most advanced regional climate projection capability of the region.

Specifically, we have run an ensemble of TWELVE high-resolution regional climate simulations (12-km grid spacing) for 130 years (1970-2100).  

Each of these simulations was driven by a different global climate model.  Such global models have such coarse resolution that they make profound errors with our local terrain.  Thus, we applied a proven high-resolution weather forecasting model (WRF) to properly simulation regional weather effects, running it for 130 years. 

Global climate model (left) versus our high-resolution regional model (right).

In our simulations, we have assumed the worst case scenario for increasing greenhouse gases (known as RCP 8.5), which assumes increasing use of coal and fossil fuels.  CO2 rising rapidly. 

Reality will probably be more benign, as increased renewables come online, the use of coal declines, and hopefully there will be a revolution in the use of nuclear energy (both safe fission and fusion).  And with increased energy sources, sequestration of CO2 (removing it from the atmosphere) become more viable.

Our work demanded enormous computer resources, with much of it supplied by a grant from the Amazon Catalyst Program.  The Amazon folks also helped support some of the researchers that completed and analyzed the output, and guided us in our use of cloud computing.  So a big thanks to Amazon.

What I am about to show you is unique:  no other regional climate prediction effort provides such a high resolution view of the future climate of the Northwest or offers information about the uncertainties in the projections.

Precipitation

There is a lot of talk about climate change bringing drought to the region, so let's see what state-of-science models suggest. 

I will start by show you the change in annual precipitation over the region between 1970-2000 (think 1985) and 2030-2060 (think 2045).  This graphics shows changes in the averages of all twelve forecasts.  The average of an ensemble of many forecasts is generally more skillful than the individual predictions.

For most of the region, annual precipitation will increase by1-4 inches, with some decreases on the lee (downwind) side of some major terrain barriers.  In general, MORE water for our region each year.  Good news.

What about during the summer? 

For about 2/3rds of the region, amounts will decline, but most of the declines will be small (0 to .5 inches).  The biggest declines (up to roughly 1 inch) will be on the western side of the Cascades and the western slopes of Vancouver Is.   Interestingly some of the region, particularly east of the Cascade crest, will see small increases, with largest increases over the northern Rockies.

 Bottom line:  no major precipitation declines over the arid eastern side of Oregon and Washington.


What about Seattle? What can you expect for precipitation and how good are our simulations?  Good question.

The key precipitation period is midwinter...and below is a plot of all ensemble members, the average of all of them (green line) and observed values (black dot) for 1970-2100.

A very small upward trend in winter precipitation through 2050.  You won't notice it.  Also note that there has not been much trend in the observations either.

What about summer (June to August) in Seattle?   The forecast is below.  

A very slight downward trend.   Summer has always been dry around Puget Sound (typically 2-3 inches in total) and perhaps we will lose as much as .5 inches from global warming by 2050.  

How about Omak in the fire-prone mountainous area of northeast Washington? As shown in the projections below, it is a dry place with little trend.


The bottom line of these forecasts is that the precipitation changes through 2050 over our region will be modest, even if greenhouse gases increase rapidly over the next several decades.  

Temperature

Increasing greenhouse gases WILL have a significant impact on our regional temperatures, but how much?  Let's check out maximum temperatures.

Annual average maximum temperatures by 2030-2060 (think 2045) will increase by 1-2 C (2-4F) west of the Cascade crest and 2-3 C (4-5F)  to the east.


What about the summer, where we worry about heat waves and wildfires?  

Clearly larger increases in temperature (see below).  Along the coast, pretty much the same as for winter-- 2C or less increase in temperate.  The ocean temperatures do not warm up as rapidly as the land, so relief from heat will remain available from Forks to Astoria to Lincoln City along the coast.

Summer temperatures in Puget Sound will notch up by about 2.5- 3 C (4-5F).   So a typical summer high in Seattle would increase from approximately 76F to around 80F.
East of the Cascade crest, summer high temperatures will increase 3-3.5C (5-6F), so the typical summer high in say Richland, WA will rise from 88F to 93.5F.  Enough to be noticeable.

Below is a plot of how the daily average winter (Dec-Feb)  temperature (C) will change at SeaTac through 2050. Again, the green line is the average of the ensemble of regional climate forecasts.  A slow increase over time by about 2 C.

The summer temperatures also increase steadily, by about 3 C.   Note in 2020 we have already experienced about half of the greenhouse warming that is expected by 2050.

By the way, do you notice that the high-resolution model is too cold in winter and too warm in summer at SeaTac?  This error is probably due to the lack of resolution even of the regional climate simulations, with an inability to define the relatively narrow Puget Sound west of SeaTac.

Omak mean temperatures in winter and summer?  A gradual increase, with summer temperatures going up 2-4C over the period (and we are again about halfway there at this point).

Omak Winter

Omak Summer

Bottom Line:  Assuming a worst-case scenario of increased greenhouse gases, the region will warm, with greatest increases east of the Cascade crest.    Winter warming (from approximately 1985 to 2045) will be approximately 3F in the west and 5 F in the east.  Summer warming will be roughly 4F in the west and 4-5F in the cast.  Warming will be gradual and progressive.

Snowpack

With only a modest rise in precipitation but warming temperatures, one should expect a decline in snowpack--and that is exactly what the regional simulations are showing.

Here is the change in April 1 snowpack (snow water equivalent in mm), a critical measure of melt water availability for the summer, between roughly 1985 and 2045.  Notable declines  (darker brown colors) over the western slopes of the Cascades and the Olympics.  Some increases in eastern WA (from the increases in precipitation).


To get a more intuitive idea of the April 1 snowpack change below are the ensemble forecasts and ensemble mean (green line) at Stevens Pass.  You will note a lot of variability in the forecasts and observations--snow amounts vary a lot from year to year for a variety of reasons (including natural variability such as El Nino/La Nina).  Over the entire period through 2050, the snowpack declines from roughly 1000 mm (1 meter) to around 750 mm:  a 25% decline.

It is not clear whether there has much decline so far in the observed snowpack (black dots).
Declines in projected snowpack are less at higher locations, and greater at lower ones, such as Snoqualmie Pass.     Skiing at Snoqualmie is often marginal today and I would not buy a season pass there after 2030.   I suspect skiing will be history at Snoqualmie by 2050.

Wind Speed
    
    The regional climate simulations do NOT suggest much change in average daily maximum wind speed (see below) between 1985 and 2045.  The same is true of annual maximum gusts or the strength of approaching Pacific windstorms.


I can provide a thousand more graphics, but you get the general idea.  

If the emissions of CO2 and other greenhouse gases continue on their present pace, there will be changes in our regional climate.  In fact, some of the changes have already started.  So by 2050:
  • Annual precipitation will increase slightly for most of the region.
  • Temperatures will warm by roughly 3-5F.
  • Winds and windstorms will experience little change.
  • Snowpack will decline dramatically (roughly 25%) by 2050.
Importantly, the model projections do not suggest  any "tipping points" nor abrupt changes in our weather/climate as a result of increasing greenhouse gases.

To say something that will get me in trouble with the climate activists folks, there is no existential threat to our region through the middle of the century.  We will be able to adapt to the modest changes that are expected, although some will be worrisome (loss of skiing at Snoqualmie Pass).

Not optimal snow conditions

I believe the above is the best available estimate for what unrestrained global warming will bring to our region through mid-century, and I ask that the activist folks and over-the-top "journalists" in some local media outlets restrain their name calling and twitter rage when such information is communicated.   My erstwhile radio station, KNKX, surrendered to the climate activists--hopefully, as the political rancor of this season ends, rational discussion and good science will again be appreciated.



Stream my podcast from your favorite services:


My blog on KNKX and the Undermining of American Freedom is found hereAn extraordinary story about Matt Martinez, Director of Content of KNKX, is found here.