Thunderstorms Possible This Evening in Western Washington

 9:30  Update

The showers and thunderstorms are here (see radar image).  And cooler air is moving in from off the ocean.

Lightning at 8:10 PM:

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A line of thunderstorms is now moving up western Oregon at this time and is heading into western Washington.

A little after 2 PM, the thunderstorms were evident in the infrared satellite image, with the lightning indicated by red crosses.

A visible satellite image around 3 PM  showed the area of boomers clearly

The weather radar at 3:45 PM clearly indicates some impressive thunderstorm cells:

For short-term forecasts, the chosen tool is the NOAA HRRR model.  Here is the predicted radar image for 8 PM today.   Storms into southwest Washington and around Portland.

At 11 PM, they had moved northward towards Puget Sound.

Thanks to Dr. Peter Bender for suggesting a look at this.

Tropical Storm Moisture Will Bring Precipitation to the Northwest During the Driest Time of the Year

 We are now approaching the driest time of the year, and ironically, it is going to rain that day.  Temperatures will cool.

An important contributor will be a weakening tropical cyclone (Elida).   Below is the path of that storm from the National Hurricane Center:

And a recent infrared satellite image shows the moist storm off the northern California coast.

But where will the tropical moisture go?  You guessed it..... we will get a piece of it

Consider the forecast of atmospheric moisture from the European model over the next few days (below).

Moisture surges into our region starting late on Wednesday and hangs around through Sunday.

And this moisture will be associated with precipitation!  Here is the total through Thursday morning. You can see the remnant of tropical cyclone offshore.

And the precipitation won't stop..... take a look at the total rainfall through Wednesday morning, July 29th...the driest day of the year.  

Wow.  Lots in  British Columbia. 

Consider the forecast 24-h precipitation total ending 11 AM July 29th for our regoin.  Pretty wet for this time of the year.

Rain on this day will be personally embarrassing for me.... I had recommended that a couple get married that day if they wanted an outdoor wedding.  

Warming Temperatures.....But Western Washington And Oregon Will Miss Low-Level Smoke

During the next few days, temperatures will surge upwards west of the Cascades into the low 90s, but a significant smoke intrusion is NOT expected in the west.

This is in contrast to highly deceptive (and incorrect)  media reports, such as in the Seattle Times (see below).

In fact, a lot of media outlets are providing such inaccurate information (such as Public Radio Station KUOW:

Currently, surface air quality in the west is excellent (see the proof below). Green dots indicate very clean air.

The most powerful tool for looking at future smoke impacts is the NOAA HRRR smoke model.   

Consider the latest forecast run.   Below is the predicted low-level smoke concentration for 4 AM tomorrow morning.  Minimal smoke over the lowlands.

Ditto for 5 PM tomorrow.

And even less smoke west of the Cascades on Wednesday morning.  If you are living west of the Cascades, you will breathe easily.

There will be a short warm period (two days) with temperatures reaching as high as the low 90s, followed by a cooling to near normal levels for the rest of the month.

This is illustrated by the latest Weather.com forecast for Seattle (below).  The Weather.com forecast is generally far more accurate than the National Weather Service.  

With all the wildfire hype going on in social media and elsewhere, it is important to note that there are no major wildfires over western Washington, in the Cascades, or on the eastern slopes of that barrier.   

You want proof?  Here is the last large fire map by the USDA Forest Service:

The Cascades act as a barrier for the smoke from the easstern Washington fires or the smoke coming in from Canada.   Not easy to move the smoke down to the surface from the east.

Finally, for those worried about wildfire, it appears that there will be significant precipitation over the next week, which is close to the climatologically driest time of the year.  

To show this, below is the latest European Center total precipitation forecast over the next 8 days. 

Impressive for this time of the year.

Grass and Range Fires East of the Cascades

As expected, the massive lightning event this week led to the ignition of several wildfires.

But our region lucked out:  few fires were started on the eastern slopes of the Cascades within forested areas.  

This is because we are in the early season, which means less time for drying in the slow-to-dry forested areas, and because of the distribution of lightning (relatively little lightning on the eastern slopes).

Below is a map of the largest fires.  

Most were in grass and range vegetation, with the greatest fire activity in southeast Washington and northeast Oregon, where the most lightning occurred.

You can see the smoke in the midday high-resolution visible satellite image (as well as low marine clouds over western Washington).

Some satellites can observe the heat from the fires....and here is the same image with fire locations (orange dots).

The grass/rangeland of northeast Oregon is clearly the "hot spot" for the fires.

It is important to note that such fires have little to do with global warming or heat waves. 

 Light fuels, such as grass and range vegetation, are typically dried by now, and lightning events like this week have no correlation with a warming planet.

Want proof that the moisture level of the fuels (grass/range vegetation) was not unusual?

 Below is the data from the US Forest Service showing you the 100-hour fuel moisture levels. (100-hour fuels include dead organic materials, such as branches and dead roundwood, that measure between 1 and 3 inches in diameter.) The observed moisture levels (red line) are in the middle of the average range (gray shading).

But something has changed over the past decades the was made our grass/rangelends far more flammable...the invasion of explosive-burning cheatgrass and other fire-friendly species.

This map shows you the extent of the problem and why eastern Washington and Oregon are so vulnerable

Flammable grasses have taken over the region (see below), and ignition by lightning or human activities can start a firestorm.

And there is one more thing.  

To get large fire growth requires strong winds, and the weather systems that produced the thunderstorms also provided large wind gusts, both during the storms and after.   

Want proof?  Check out the maximum winds on Thursday (below).

Winds are declining now, and you can expect that the grass/range fires will quickly decline.

Massive Lightning Outbreak Hits The Northwest

One of the greatest Northwest lightning outbreaks in recent memory occurred today, with well over 5000 lightning strokes over the region.

Below are the strokes over the past 24 h:  very impressive.  

There were three major thunderstorm paths...one down the lowlands of western Washington, one along the coast, and a broad band in eastern Oregon and Washington.

Importantly, there were very few lightning strikes on the eastern side of the Cascades, which greatly reduced the chances of forecast fires there.

The massive lightning activity over northeast Oregon did start fires.

Normally, the Pacific Northwest is the poor stepchild of lightning activity in the U.S.  But look at the national lightning activity for the past 48 hr below.  For once, we were in the league of Florida or Texas!

The radar image this morning was enough to promote goosebumps for the meteorologically inclined:

And today's precipitation totals were quite significant, with several locations receiving over a half-inch (see today's totals below).

The visible satellite image  around 10 AM looked like something out of Oklahoma:

During the morning, several folks told me they saw funnel clouds, based on pictures like this:

I saw such clouds myself... which result from aircraft passing through a low cloud deck. NOT a tornado.

Let me end with a truly remarkable image.

Low clouds were left in the wake of the thunderstorms over western Washington, but Mount Rainier extended above the clouds. Eastern Washington is now experiencing plumes of smoke from fires ignited by the lightning over northeast Oregon. The green areas show lightning strikes.

  

 

Thunderstorms and Rain Coming to the Northwest

For most summers, during July or August there is an intrusion of "monsoon" moisture from the southwest into our region, resulting in showers and thunderstorms...and this year will be no different.

Such thunderstorms can be both good and bad.  Good at providing needed rain and lessening fire risk, but bad if lightning starts fires.

The predicted totals through Friday morning (seen below) range from a few tenths to a half inch, with higher values along the coast.

The wet fun will begin later this afternoon and evening as convection and thunderstorms build near the crest of the Cascades (see forecast for 5 PM below).

Overnight, more serious thunderstorms/convective showers will move into the region, as suggested by the forecast weather radar image at 2 AM from the University of Washington forecast system:

The latest forecast of the NOAA HRRR model is quite similar (simulated radar at 1 AM shown below).

Why this wet bounty?

Two things are occurring together.   The upper-level pattern includes an approaching upper-level trough (500 hPa, about 18,000 ft shown for tomorrow morning).  Such troughs produce upward motion (which helps initiate cumulus clouds) and bring in moisture from the south.

Such "monsoon" moisture and unstable air from the southwest are evident in the forecast below.

Total water vapor content of the atmosphere this evening.  

Blue and red are higher values

Enjoy the show overnight!

Wildfire Smoke Fills the Skies Above The Northwest

 If you viewed the skies around sunrise and sunset during the last day, it was evident that a massive cloud of smoke had moved in overhead.

For example, here is a northwest view from the Seattle PanoCam just before sunrise this morning.   Stunning.  Lots of smoke in the sky.

And if you needed more evidence that our sky was full of smoke, below is the visible satellite image at 6:52 AM this morning (Monday, July 13).  

Wow.  Lots of smoke over our region.

Yet, with all this smoke, surface air quality is excellent, as shown by the latest observations from the Puget Sound Clean Air Agency (green means good air quality).

How could this be?

The answer to this conundrum is that the smoke is located many thousands of feet aloft, so high that it can not mix down to the surface.   

To prove this, here are observations from a laser-based ceilometer in Marysville, Washington.  This device shoots a laser vertically, allowing it to sense smoke and clouds above the surface.

This morning, the smoke was around 3000 meters (about 10,000 ft) above the surface.

Where did this smoke come from?   

Not from local fires, but from major fires in the Canadian arctic and sub-arctic regions, something shown by the visible satellite image two days ago (see visible satellite image from two days ago):

This smoke then swung around an upper-level low off our coast and into our region.   I can demonstrate this with the upper-level weather map (about 18,000 ft, 500 hPa pressure) for early Sunday morning (below).  The wind barbs show the wind speed and direction.  

Air from northwest Canada moved offshore over British Columbia and then swung around the low and into the Pacific Northwest!

The pattern is now shifting, and the smoke aloft will move out of our region today.

The Best Weather In the U.S.

 If you asked Google AI where the best weather in the U.S. will be, the answer will warm your heart:

Seattle gets called out with "perfect weather conditions".    As a trained meteorologist, I concur.

The forecast high-temperature map for Sunday across the U.S. shows only one urban area in the upper 60s to low 70s: western Washington.  Even eastern Washington is reasonable.

You dislike humid conditions with high dewpoints (above 60F) and want to avoid very dry, parching air (dewpoints below 40F)?     

Western Washington and Oregon are for you! (see plot of forecast dewpoint temperatures for 5 PM Sunday below)

Want sunny skies on Sunday?   Western Washington and Oregon residents will see blue skies.

And you like some light winds, but not too strong?  The wind gust forecast for tomorrow shows perfect conditions over western Washington.

Air quality?    Clean air (green dots) over the Northwest (see below).   You can take a deep breath!

There is so much negative information today about the environment, so it is good to acknowledge when things are spectacularly nice.    

I won't get many online hits in saying this... but it is true.😋