September 18, 2023

Heavy Rain Coming to the Northwest: The End of the Wildfire Season and Beginning of the Snow Season

The region has palpably entered a fall-like period of cooling temperatures and the return of precipitation.

But to quote the old saw:   "You Ain't Seen Nothing Yet"

A moderate frontal system will move in tomorrow (Tuesday) night, bringing rain across the region (see total through 5 PM Thursday below).   Maybe a half-inch in the Cascades.  

Enough to knock back local fires to a smolder.

But the real action is still ahead.  A weak front will move in Saturday morning (see 24 hr precipitation ending 5 PM Saturday).

But that is not the main story.  Early next week a potent atmospheric river of substantial moisture will be headed into our region (see total water in a vertical column for 5 PM Monday).  Mama Mia! That is a decent atmospheric river.  Blue indicates lots of water vapor heading our way.

The result will be bountiful local rainfall, as the moist air is forced to rise by our regional terrain.

The 24-hour precipitation total ending 5 AM Tuesday includes several inches in our mountains.

And the 72h precipitation total ending Wednesday morning has as much as ten inches at high elevations. Wow.

Folks this will end the local wildfire season, which has been below normal this year.  And with lots of moisture coming in and moderating temperatures, the higher elevations will start to pick up the first snow of the season (see forecast snow total map through September 28).

September 16, 2023

The Last 80 Degree Day This Year For Puget Sound Country?

Yesterday's high at SeaTac was 84F and today much of the central and south Sound reached the upper 70s to low 80sF.  

But with a significant shift towards a more autumn-like pattern this week and a rapidly weakening sun, there is a good chance that SeaTac Airport and much of Puget Sound country will not see another eighty-degree day until next spring.

Take a look at the visible satellite image this afternoon (below).  The Pacific Ocean does not have a summertime look!  A weak, but broad, frontal system is offshore and some of its clouds are moving in tonight.  A more potent cyclone and front is now over the Gulf of Alaska, and we will get a taste of its southern portions in a few days.

The most notable feature in this morning's satellite image was a plume of smoke from a few small, lightning-caused fires near Hurricane Ridge in the Olympic Peninsula.  Considering its location and its natural origin, the Park Service is letting it run its course.

Turning to the forecast, here are the predicted temperatures through 26 September in Seattle.  Highs in the 60s and lower 70s.

As shown by the climatology data for SEATAC, with the red shading showing all-time daily records, once one gets into October, hitting 80F is increasingly unlikely, after mid-October it never has happened!

What about rain?   

We are likely to get some.  

The first band will be relatively weak, with the total through 5 PM Monday only bringing light showers to western WA, but more meaningful precipitation over southwest BC.   Cooler temperatures and high humidity will knock back the Olympic Mountain fires.

The second, more potent system will come in on Tuesday/Wednesday morning, with real rain over NW Washington and southwest BC.

Finally, I am getting a number of complaints from blog readers in southern CA about the wet summer.  Did you know this was the wettest summer on record in Los Angeles... going all the way back to the 1940s?  Wow.

As a result of bountiful California rain and cooler-than-normal temperatures, wildfires are well below normal this year in CA (and were also below normal last year).  

Want the proof?  Here are the last statistics from CALFIRE, the official fire agency in California.  The media likes to paint an "end of world" picture about wildfires, but the truth is different.

September 14, 2023

A Stunningly Good Hurricane Forecast

 Numerical weather prediction has improved dramatically over the past decades, providing potent warnings for extreme weather, such as hurricanes.

There are few better examples than the prediction of Hurricane Lee, which will make landfall near the Maine/New Brunswick border late Saturday.

The U.S. global model, the GFS, has been spectacularly skillful in predicting this storm, well more than a week ahead.

The latest forecast run shows the storm making landfall near the international border around 5 PM PDT on Sunday.  That is a 54-h hour prediction  This is so close enough in time...and so consistent with other model forecasts... that you can be assured that this is close to what will happen.

But how did extended forecasts do?

The 72-h prediction is pretty much the same.

The 126 h prediction is nearly identical in position:

The 198 hr (8.25 day) forecast has a strong hurricane in pretty much the same location.

Folks, this is a stunningly good forecast for over a week ahead.

Professor Brian Tang of the University of Albany has a wonderful website that verifies the hurricane track (position) forecasts of major modeling/forecasting systems.  The results for Hurricane Lee are shown below for forecasts of 120 hours (5 days) or less.  

In general,  the track accuracy gets better for shorter forecasts...which makes sense. But let's compare the American model (blue color, AVNO), the European Center model (red color), and the UKMET office model (green color).  The human (official) forecast is shown in black.

Wow.  The American model is STUNNINGLY accurate at all projections in time.  

It is FAR better than the nominally top two global modeling systems in the world:  the European Center and UKMET.  The forecast error is under 100 km (60 miles) for all projections shown. 


The model forecasts are better than the official Hurricane Center forecasts....I suspect that humans are probably hedging their bets with the European Center model solution.😅

This was a truly excellent forecast and not the only success for the American model this season.  Hopefully, this extraordinary performance will be persistent for future storms, perhaps reflecting recent improvements in the U.S. global modeling system.

Finally, I should note there are real policy implications of the rapidly advancing weather prediction skill now available to decision-makers.  Excellent forecasts can help protect people and economic assets from extreme weather.

Better forecasts are the first line of defense against severe weather. 

 Better forecasts have great potential for reducing the negative impacts of global warming.  

One of the reasons I have spent some time trying to calm down some who are panicking over global warming and extreme weather.

Climate-related deaths are down...and I mean WAY down.  Better adaptation and a richer world have contributed, but so have better forecasts.

Importantly, we have only begun taking advantage of improved forecast skill.  

The winds on Maui were nearly perfectly predicted on August 7-8 of this year, yet 115 people died and nearly 10 billion dollars in damage was done. We could have easily stopped the carnage, by shutting off the power and effectively evacuating the population.

Most major wildfires are related to strong winds and such winds are often forecast with great skill.  Few should be a surprise.

In summary, coastal New England has had nearly a week to prepare for strong winds and heavy precipitation (over northern Maine)-- and we can be proud of the technological advances and investments in NOAA  and in other government agencies that made such forecasting prowess possible.

September 12, 2023

The Transition to Meteorological Fall

 Today was cool, mostly cloudy, with some showers.  There was a real autumn feel to the air.  Days are rapidly getting shorter and the strength of the sun is noticeably less.

Rapidly, the jet stream...the strong west-to-east current of air in the upper troposphere.. has strengthened....and the forecast of upper-level winds for Saturday afternoon shows a strong current of winds extending across the Pacific (see below).  Reds are the strongest winds.

The jet stream is driven by the north-south temperature difference, so as the Arctic rapidly cools, the temperature change and associated jet stream strengthen.

Right now, most of the jet stream action is north of us, but late Sunday and Monday, western Washington and BC will get a piece of it.  Below is the 72-hour total precipitation ending 5 AM Wednesday.   Wow.  Southern BC will get some heavy rain.

As the jet stream and cooler air slide towards us, temperatures will not get out of the 60s early next week in Seattle (see below).

This has been one of the most benign wildfire seasons in years (yes, the Seattle Times was totally wrong) and the cooling/wet conditions will pretty much guarantee the current wildfire season will now fade.  Currently, there are only a few small, lightning-initiated fires over the south Cascades (see below), and they are fading rapidly.

The big weather action in a few days will be the approach of Hurricane Lee, with a very powerful storm affecting New England and the Canadian Maritime Provinces on Friday through Sunday (see forecast for last Saturday below).   A very dangerous storm.   More on Lee in my next blog!

September 10, 2023

The Seattle Times Pushes Climate Anxiety

Yesterday's print edition of the Seattle Times features a letter to the Editor from a local psychologist describing the acute fear of climate change that has become widespread among her patients.  Dr. Schweigler stated:

 In my psychotherapy practice of 30-plus years, I have not seen such a common theme of existential anxiety created not by individual psychodynamics but by profound fear about the state of the Earth.

Might the Seattle Times be fostering climate anxiety and fear?   The answer was on THE SAME PAGE as yesterday's paper, with a cartoon by David Horsey, showing a climate-caused fire devil burning homes and destroying powerlines.

It was telling that the editors of the Seattle Times did not think about the juxtaposition of a letter bemoaning a plague of climate fear with a scary cartoon designed to promote such fear.  

Fear that is substantially unfounded (e.g., climate change plays only a small role, if any, regarding major wildfires such as the Maui fire).

The Editors of the Seattle Times should sit down and consider their major role in encouraging climate fear among the most vulnerable.  Their cartoonist David Horsey is one of the most provocative and irresponsible among the ST staff.

Here is another recent cartoon with the same climate change devil.

Or his holiday special about climate change coming to town.

To make sure that we are sufficiently scared, he notes that the Native Americans will have to run, storms will get huge, and coastlines will sink.   Much of this is simply wrong.  For example, there is no evidence that storms "will get huge" under climate change.

And Mr. Horsey suggests climate change buzz saw will but us to pieces when our clothes are off!

"Conveniently" the Seattle Times does not allow comments on Mr. Horsey's cartoons because prior comments have been critical.  This is often true of other climate articles.

To make sure the editorial position of the Seattle Times is sufficiently clear, Alex Freyer, the Seattle Times opinion columnist, wrote a long screed on how he wakes up at 3 AM almost every night,  gripped with fear about climate change.  He states that the "world as we know it is coming to an end."   

Mr. Freyer is so terrified of climate change that his mental health is being undermined.  Perhaps he should make an appointment with Dr. Schweigler.  Or he could stop by my office and I could tell him what the best science suggests (slow warming we can deal with).

Seattle Times editors maintain a steady stream of fearful letters to the editor, many of them factually in error (like the one below on the Maui wildifre).

And day after day the Seattle Times has bold type headlines about one climate terror after another

Climate change threatens hydropower!

Climate change heatwaves are killing older women and violating their rights!

Climate change is causing ticks to spread into the Northwest and threatening women's health!

Climate change is worsening BOTH floods and droughts!  

And yes, climate change will turn Colorado into Arizona!

I could easily give you another dozen examples of the most fear-inducing, hyper-exaggerated headlines in the Times.   But you get the point.

The Seattle Times and its ilk are being highly irresponsible.   They are undermining the mental health of vulnerable people.  Causing fear and anxiety.  And much of what they are hyperventilated about about is simply untrue.   Easily proven to be false.

It is time for the Seattle Times to look itself carefully in the mirror.   They might not be comfortable with what they see.

September 08, 2023

Major El Nino Developing

The upcoming winter may be an interesting one for the West Coast.

A very strong El Nino is rapidly developing.   Strong enough that it could significantly alter the atmospheric circulation during the upcoming cool season, particularly after January 1.

As I have mentioned many times in this blog, El Nino is associated with warmer-than-normal sea surface temperature conditions over the central and eastern tropical Pacific.

The most frequent tool for monitoring the potential for El Nino (and its opposite La Nina) is the sea surface temperature averaged over an area in the tropical Pacific, known as the Nino 3.4 area (see map below)

Major changes have occurred this year as we transitioned from La Nina conditions (colder than normal temperatures in the Nino 3.4 area) to a moderate El Nino (see plot below). In the figure, the Y-axis shows the temperature difference from normal in that area.

We are now solidly a moderate El Nino and the tropical ocean is still warming.

A map of the sea surface temperature differences from normal (the anomaly) is shown below.  Mama Mia!  That is a warm equatorial ocean.

In the U.S. the NOAA/NWS Climate Prediction Center (CPC) is responsible for predicting El Nino and La Nina situations.  This is such a strong event and they are so sure that CPC is basically going a 100% for El Nino.

Why are they so sure?  Because both simulation models and statistical approaches are going for an increasing El Nino, as shown below.    We are talking about strong El Nino territory!
So what does a strong El Nino mean for our weather this winter?   

A warm tropical Pacific has an impact on the atmosphere that extends into the midlatitudes, particularly after the New Year.  In general, historical statistics suggest that the Northwest is a bit drier and warmer than normal and California gets more precipitation than normal.

Let's also check the latest seasonal simulation forecasts ( from NMME).  

The forecast for the precipitation anomaly from normal for January-March is for a dry Northwest and a wet California.  Classic.

And temperatures are predicted to be warmer than normal on the West Coast.

Let me make clear that the correlation between El Nino and West Coast weather is useful but not perfect.  

Think of it weighting the atmospheric dice.  But I would think carefully about buying that seasonal ski pass for a lower-elevation venue.

September 06, 2023

Near Perfect Weather for the Next Ten Days

 Perfect temperatures, no rain, and little smoke.

What is left to say?

Substantial rain last week has knocked back the smokers in British Columbia and there are only a few small fires over the southern Cascades.   FAR less fires than normal in fire-prone California.

Thus, the latest Purple Air surface air quality sites indicate mainly green colors (good air quality) over the Northwest, including much of southern BC.

And the NOAA HRRR smoke model has a very benign surface air quality forecast for 5 PM Friday (see below).

The latest forecast for Seattle suggests a slow warming into Saturday, but nothing extreme...77F. (see below)

Close to perfect.  Followed by a modest cool-down next week.

Eastern Washington will top out around 90F over the weekend.

I really wish I could forecast some weather excitement, but we have a boringly optimal period ahead.

But changes are occurring to our north and west.  The temperature difference between the subtropics and Arctic regions is growing and that helps drive the upper tropospheric jet stream, centered around 30,000 to 35,000 ft. 

The figure below shows the winds around 30,000 ft next Tuesday, with the jet stream indicated by the stronger winds (green to orange and red colors).       The jet stream, which acts as a conduit for storms, will be headed into BC.

With a persistent jet stream to our north, BC and southeast Alaska will get plenty of precipitation (see total through Wednesday below).  Gray and reds are the most.

During October the jet stream will slide south and the moisture stream will reach us.

But enjoy perfect weather in the meantime.

Heavy Rain Coming to the Northwest: The End of the Wildfire Season and Beginning of the Snow Season

The region has palpably entered a fall-like period of cooling temperatures and the return of precipitation. But to quote the old saw:    &qu...