May 18, 2022

The Big May Blow

 The mid-May wind event is now past its peak, but not before thousands of customers lost power.

The water vapor satellite image at 4 AM this morning was impressive, with plumes of moisture circling into the clear "eye" of the storm.  Not your typical May satellite image!

The maximum wind gusts ranged from around 50 mph on the coast and 50-55 mph over Northwest Washington to over 60 mph on the eastern slopes of the Cascades.  


But if you really like winds, head to Mount Rainier, where gusts hit Camp Muir (at 10,000 ft), 52 mph at Sunrise Ranger station, and 66 mph at Crystal Mountain.


Strong winds combined with leafed trees led to power outages around the region, with about 5000 City Light customers losing power and roughly 20,000 Puget Sound Energy users (see outage maps below)


And now the exciting news, we FINALLY will have a truly decent weekend coming up.  In western Washington, highs reach the mid-60s on Saturday and around 70F on Sunday (see forecast map for Sunday at 5 PM below).  Even mid-70s in the Columbia Basin.  Get ready to garden, hike, or take a stroll outside.  It will be perfect...for a change.





May 17, 2022

A Winter Storm is Approaching: In May!

This May we are experiencing winter-like levels of precipitation, winter-like increases in the snowpack, and record-breaking cool temperatures.

The only thing missing is a winter-like Pacific storm, with deep low pressure and strong winds.

Well, it won't be missing tomorrow:   a strong Pacific cyclone will make landfall on the British Columbia coast and gusty, damaging winds could batter the coast and Northwest Washington.

Even Puget Sound country will get a piece of it.

The low center will be making landfall on northern Vancouver Island at about 8 AM tomorrow (Wednesday), as shown by the predicted sea level pressure map at that time (see below).


The solid lines are isobars, lines of constant pressure.  Where there are large gradients (large change in pressure), strong winds are expected.  Folks, there are a LOT of isobars there.

Winds will be ferocious over the ocean, with gusts near the low center reaching 50-70 mph.  

I hope no Alaska cruise ships will be traversing the region tomorrow morning.  It might dampen the appetites of the passengers.😊

Take a look at the predicted wind gusts at 5 AM Wednesday.  Over 50 mph over the Pacific and across portions of Northwest Washington.  Going to be very windy in the San Juans, Victoria, and the eastern Strait of Juan de Fuca.

From City of Seattle WindWatch

And then as the low center moves eastward across southern BC, strong winds will surge eastward into the Strait of Juan de Fuca and winds will gust around Puget Sound (see the forecast wins at 2 PM Wednesday)

Seattle WindWatch

The latest wind forecasts over Seattle indicate the wind potential for Wednesday morning and afternoon (see below).  The red line is from the UW high-resolution forecast system...and is usually the most skillful.  It is predicting gusts exceeding 40 mph in exposed locations over Seattle.  With leaves on the trees, expect some branches to fall.

Seattle WindWatch
 
How usual is it to get such an event in May?  

Quite unusual.  This figure below shows the forecast pressures at 11 PM tonight at around 800 meters above sea level (solid line) as well as the standardized anomalies of the winds at that level (colors).  Such anomalies from climatological conditions are expressed in standard deviations and are quantitative measures of how usual a weather event is.   Impressively, the wind anomalies climb to 5 standard deviations, which means unprecedented in the 30-year period used in the calculations.  



Bottom line:  an unusually strong storm in an unusually cool, wet spring.


May 15, 2022

La Nina is Not Going Away. What does the mean for this summer's weather?

 It is now clear that La Nina is not going away, and may hang around into next winter.   

Cold water is entrenched over the central and eastern tropical Pacific (the definition of La Nina) and the latest forecast model runs suggest a continuation into fall.

Several of you have asked:   what does this imply for our summer weather?

Let me tell you.   

But first, the bottom line:   the summer effects of La Nina are modest, but will push the western side of our region towards cooler than normal conditions.

The Impacts

During La Nina years, sea surface temperatures off the West coast are usually cooler than normal, and those cooling effects spread inland. 

 To illustrate, here is the sea surface temperate difference from normal for the summer months (May through September) for La Nina years.    Blue colors are cooler than normal.

And if we average surface air temperatures for La Nina summers and subtract those temperatures from normal, we find that cooler than normal summer temperatures (e.g., green colors in the figure below) occur from California to Washington during La Nina summers (temperatures anomalies in degree C are shown below).


In contrast, West Coast precipitation is hardly changed...perhaps slightly drier on the western sides of the Cascades.  I suspect this is because the colder water works against thunderstorms.  Interestingly, La Nina seems to have more summer impact over the Midwest U.S.



Summer versus Winter

La Nina (and El Nino) have far more impact on West Coast weather during winter and early spring than summer.    The atmosphere is far more active during the cool season, with stronger, more active flow in the midlatitudes and more interaction between the tropics and midlatitudes.

A Record-Breaking Spring

As I will detail in a future blog, we are on track to "enjoy" the coolest spring in a half-century.  Right now, the average April/May high temperature at SeaTac is the second-lowest in the past 50 years (see below).  And there are a lot of cold temperatures ahead.


And at Yakima, this spring IS the coldest by far.


La Nina gets part of the blame...but not all.

And I hate to tell you this.... record-breaking cold will be returning later this week.  So don't put your sweaters away yet.

May 13, 2022

What you should know about surface temperature, and another winter-like week ahead. All in my podcast.

You check the "temperature" on your smartphone or another device.  

 What does it really mean?  

It turns out that temperature is not as simple as you might assume.

Can the temperature at the ground be very different than reported on your device or on TV?  Yes, it can.

Can the time of maximum temperature vary at various depths in the soil?  You bet.

And knowing about the nature of surface temperature can save your life.

All is explained in my podcast.

My podcast also includes a review of the dismal week ahead.

Here is the total precipitation forecast for the next week.   Up to FIVE INCHES in the mountains.   And lots in eastern Washington.  Potential for flooding on a few Washington rivers.

Lots of snow above 4000 ft! (see below).  There will be good skiing at Whistler way into June. Several feet will fall in the mountains of British Columbia.

And extraordinary cold is being forecast for the next ten days (see European Center forecast below).  Very unusual.


The cold, wet story is found in my podcast (see below).


To listen to my podcast, use the link below or access it through your favorite podcast service.


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May 12, 2022

Pressure Data from Smartphones Could Greatly Improve Weather Prediction: Will Big Tech Help?

Meteorologists need the help of Big Tech to improve weather prediction and save lives.

How? By collecting pressures from smartphones.  

This blog asks for their assistance.

There is no more useful weather observation than surface pressure.  With surface pressure alone, one can determine the three-dimensional structure of the atmosphere, sense the precursors of severe thunderstorms, and much much more.

Many smartphones include excellent pressure sensors, mainly to help determine elevation.  

With billions of smartphones with pressure sensors around the world, there exists the potential to greatly improve weather forecasts, particularly in third-world countries with sparse weather observations and for severe thunderstorms in the U.S.


There are research groups, including my own, that have solved the technical issues of calibrating smartphone pressures using machine learning and making the observations anonymous.

But there is a major problem:  collecting the pressures from smartphones.   To solve the problem, we need the help of the tech
community:  Apple, Google, Amazon, Samsung, Facebook, Twitter, Instagram, Microsoft, or others.

Help that could revolutionize weather prediction and save many lives.

The Demonstrated Potential of Smartphones to Greatly Improve Weather Prediction

The current generation of smartphones has pressure sensors as good as those used in many weather stations.   

A decade ago, some of us realized the potential and found a source:   IBM/the Weather Channel app.  (IBM bought the Weather Company, including the Weather Channel smartphone app).  When people checked the forecast with the Weather Channel app, their atmospheric pressure was retrieved and archived.   

With extraordinary cooperation from IBM,  IBM gave the UW access to the smartphone pressures, about 60 million observations a day mainly in the U.S.

Below is a sample of the distribution of smartphone pressures at a single hour in 2018.  There is an extraordinary density of observations in the eastern half of the US, but plenty in the West.  Keep in mind that this sample is from a single app reporting from perhaps one out of a thousand smartphones.

To show the value of smartphones, consider the landfall of Hurricane Michael on the Gulf Coast on October 10, 2018 (see below).  The top right panel shows the normal data collection (each dot is pressure observation, color-coded by pressure--red is high, green/blue is low.  With power outages, many traditional observing locations were offline, but the smartphone observations were numerous and clearly showed the location of the eye.

For the recent, devastating Marshall Fire near Boulder, Colorado, smartphone pressures defined the low-pressure features that drove the strong winds (dark red colors on the map below)--something the traditional weather network missed.

I could show you many more examples like this, such as for strong thunderstorms, where the smartphone pressures delineate critical details.

I can also show you forecasts in which the use of smartphone pressures improved the forecast.   To provide a local example, the figure below shows you a radar image (left panel) indicating a Puget Sound Convergence Zone (inside the red circle), a frequent weather feature of western Washington.  To the right are two forecasts, one using smartphone pressures and the other without.  Without the smartphone observation, the forecast system does not predict a convergence zone (middle panel), but with regional smartphone observations, it does!


The Technological Hurdles Conquered

There were several technical hurdles that needed to be conquered and this was done by my recent Ph.D. student, Callie McNicholas.  

First, each phone has a different pressure bias/error and the elevation of phones vary.  I won't go into details, but using machine learning and the GPS elevation/position information provided for each phone, we were able to successfully calibrate the phone pressures.

Second, since folks are rightfully concerned about privacy, we had to anonymize the pressure observations.  We did this by adding random noise to the location and collecting the pressures in small boxes with several observations.  Even with our steps to ensure privacy, the smartphone pressures (smart-anon in the figure below) had less error than the current National Weather observations (MADIS).    An extraordinary achievement of Dr. McNicholas!

Helping the Second and Third World

We can prove that even the moderate smartphone pressure density provided by IBM/WeatherChannel can help improve our analysis of surface pressure and enhance forecasts over the relatively data-rich U.S.   But the real quantum leap may be over the second and third world where this are many smartphone users but poor meteorological observation networks.  The map of surface observations used by the European Center for Medium-Range Weather Forecasting for December 2020 is shown below.   LOTS of observations over Europe, but major holes over Africa and South America.

Why We Need Big Tech's Help

We should be able to greatly improve weather prediction if meteorologists can secure a lot more pressure data from smartphones  

And only big tech can provide this data.  Only they have apps on many phones or control the operating system on the phones.

For example, Google, which controls the Android operating system and major apps--like google maps, could solve the problem.

Can anyone in Google help?  Or contact someone that can help in Google?

Apple, which controls the iPhone operating system and many apps, could make it happen.  

Facebook or Twitter, with huge numbers of folks using their apps on smartphones, could supply the data.

Amazon has apps that are on many smartphones.

You get the picture.  We can greatly improve weather forecasting, 
but the assistance of one or several of the major tech firms is needed.

Are there any readers of this blog that can help?

If so, give me a call, email, or leave a comment.




May 10, 2022

Winter Rainfall in Spring

 One of the problems in being a meteorologist is that you suffer twice with bad weather:  once with the forecast and then again when you experience the ill weather.

And the suffering is getting worse.

Tomorrow will be the last dry day for a long time, and this May will end up with rainfall more appropriate for February.

Let me show you the dismal story in 48-h chunks.  

Wednesday will be mainly dry, but Thursday will be wet, with the 48-h precipitation total ending 5 AM Friday (below) showing a moderate atmospheric river coming in off the Pacific, with rain enhanced over the mountains.



During the next 48-h the precipitation revs up over Oregon, with some locations receiving over 2 inches (see below)

Over the next 7 days, the totals are...well..scary, with a number of mountain areas getting three to five inches.  A lot any time of the year, but unusual for May.

Eastern Washington gets substantial rain, particularly in the "extreme drought" area from Yakima to Moses Lake. Rivers are also above normal within the drought warning area.

If you want to view the relentless nature of the upcoming precipitation, check out the prediction of rainfall at Seattle from the NOAA/National Weather Service GEFS ensemble system (see below).    Each gray line is the cumulative rainfall at SeaTac for a different forecast and time increases to the right.  The black line is the average of all the forecasts.  Starting tomorrow, there will be nearly continuous rain, with SeaTac ending up with 2 additional inches.


Keep in mind that the normal TOTAL for the month is 2 inches and we already have two inches in the rain gauge.   So we will have TWICE the normal rainfall by May 19th....and the month will not be over.

Now the really depressing thing is that normally there is a major warm spell in mid-May, one that always came like clockwork.  But not this year.

Do you want to experience 70F or more during the next few weeks?  Go to Hawaii.

The latest extended European Center temperature forecast is predicting much colder than normal conditions into the end of June (see below, blue colors are below normal).  Unbelievable.

Thursday will probably break the record for having the record low high temperature at many western WA locations.

 Being cold and wet through May, with a bountiful snowpack, has major positive implications for the wildfire season, something I will discuss in a future blog.

May 08, 2022

The Coldest April in the Satellite Record over the Pacific Northwest

 You knew it was colder than normal over the Pacific Northwest during April.

But the cold was not limited to the surface.   Let me show you the chilly story in a very new way:  using satellite temperature soundings in the vertical.

By measuring infrared or microwave radiation emitted by the atmosphere, satellites can measure how temperature varies in the vertical.  Not unlike how infrared ear thermometers work by sensing the radiation emitted by your eardrum!

Below are the differences from normal of the April temperatures in the lowest 10 km (lowest 33, 000 ft) of the atmosphere, with normal being the average for 1991 through 2020.  

Blues are colder than normal and yellow/oranges are warmer than normal.   This map and associated data were provided by Professor John Christy of the University of Alabama in Huntsville, who is a well-known expert in such work.

The coldest temperature anomalies (differences from normal) over the entire planet are found the Pacific Northwest, with the deviations from normal exceeding 2.5 C! (4.5F).    A blow-up for the Northwest is shown below.



But there is another point you need to consider: there are all kinds of temperature anomalies all over the planet, including a major warm anomaly over Kazakstan.  

Differences from normal, both warm and cold,  are....well...normal.    These patterns occur naturally as troughs (low pressure) and ridges (high pressure) move and develop.

But there is more!    This cold anomaly over the Northwest is the COLDEST ever observed since the beginning of satellite temperatures collection (1979).  This is shown in the plot below.  

You will also notice something that else that is very important...there is little long-term trend for April temperatures over our region.   This is consistent with the observation that our snowpack has shown little long-term trend over the region.

May is Not Any Better

And now the depressing part.   May is also turning out to be cool....and wet.

At Sea Tac Airport, every day but one in May has been below normal, with highs on many days around TEN DEGREES below normal.

Slightly better in eastern WA, with Pasco's temperature reaching normal highs twice this month.


The silver lining in all of this is that with lots of precipitation and cold temperatures, the snowpack has surged to well above normal for the entire state (see below).  Late ski season.  Delays wildfire season.  Lots of water for the summer.


During the last 24 hour,  NINETEEN INCHES of snow has fallen at Timberline Lodge on the slopes of Mt. Hood.  Amazing.



And now the REALLY depressing news for lovers of warmth.  The latest European Center ensemble forecast for the next ten days predicts MUCH cooler than normal temperatures over the region.


No wonder my tomato plants are unhappy......



May 06, 2022

Triple Dip La Nina and A Wet Week Ahead: All in My New Podcast

La Nina's generally occur one at a time.  

Occasionally, like this year, two occur in a row.

But it looks quite possible that we make experience an unusual triple-dip La Nina, with the cold water phenomenon occurring three times in a row.

Right now the Climate Prediction Center is going for a greater than 50% chance of a triple-dip  (see below) and some of the latest model runs are agreeing.


In my podcast (see information on listening below), I will discuss the situation and the implications of another La Nina year for the Northwest and California. 

But there is more.  

A very wet period is ahead of western Oregon, with the rest of the region getting a piece of the soggy action.  The forecast of accumulated precipitation for the region over the next week is startling, with 3 inches or more in the mountains (see below). 

This is A LOT for May.  And the wheat farmers of southeast Washington will get even more welcome precipitation.


To listen to my podcast, use the link below or access it through your favorite podcast service.


Some major podcast servers:

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The Big May Blow

 The mid-May wind event is now past its peak, but not before thousands of customers lost power. The water vapor satellite image at 4 AM this...