Tag: snowpack

Does Low Snowpack Increase the Chances of Washington State Wildfires?

You hear this all the time in the media and by climate advocacy groups:

A below-normal snowpack means enhanced wildfire danger in Washington State.

From Cliff Mass Weather Blog

By CliffMass

You hear this all the time in the media and by climate advocacy groups:

A below-normal snowpack means enhanced wildfire danger in Washington State.

Some samples are shown below:

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The truth is that such claims are not true.   Snowpack variability has very little correlation with the area of local wildfires.

Other meteorological conditions are FAR more important than snowpack regarding wildfire acreage and the large wildfires in our region.

The facts are very clear.   To demonstrate the lack of relationship between snowpack and wildfire area, below is a plot of April 1 snowpack (the standard measure)–shown by the blue line– and the annual acreage of burned area–red line– for Washington State for 2002 to 2025.

You will notice very little correlation between the two lines.  Snowpack has ups and downs, perhaps a slight downward trend.  Wildfire acreage has wild excursions that generally are not associated with changes in snowpack.

Of the 24 years shown, only ONE (2015) had a combination of low snowpack and large wildfire area.  But it was NOT because of snowpack.

The year was unusual for other reasons, with a crazy, persistent summer ridge of high pressure over the region, that produced very anomalous high temperatures–something shown below, and lack of summer precipitation.  2015 was the hottest summer on record in our region.

he facts are very clear. 

Snowpack has very little to do with regional wildfires.   High temperature during the summer is a major contributor, since it contributes to drying of surface fuels.   High winds are a contributor to some of the biggest fires, since winds can fan and spread the flames, and can contribute to fire ignition (e.g, from wildfires).  Low summer relative humidity is a contributor.  Low summer precipitation can contribute since that leads to low fuel moisture.

Snowpack has little to do with our local wildfires.  During a normal year, the snowpack has generally melted by early summer over the lower to middle elevations where most wildfires occur. Remember, most of wildfire are in mid-summer to early fall.   Interestingly, above-normal snowfall can contribute to MORE wildfires if it provides moisture for more vegetative growth.  Vegetation that later dries and becomes flammable.

Why is the Seattle Times and others providing obviously false information to the public about snowpack and wildfire?  Even Google’s AI knows better:

Is the Low Snowpack this Year a Sign of Global Warming?

This incurious article does not review the trend of mountain snowpack over the past several decades: a crucial test of whether climate change could be blamed.


From The Cliff Mass Weather Blog

Cliff Mass

The poor coverage of snowpack trends in the Seattle Times and other newspapers was very evident today on the front page of our local newspaper (see below). 

A story “Winter has arrived, snow not so much” filled the right side of the front page.  A reprint of a NY Times article by Mike Baker, this story suggests that the lack of snow was the result of global warming/climate change (see below).

Amazingly, this article neglects the key reason why our snowpack is not doing too well:  this is a very strong El Nino year.  

This incurious article does not review the trend of mountain snowpack over the past several decades: a crucial test of whether climate change could be blamed.

Just poor journalism.   But let’s do the proper analysis in this blog, and you can decide for yourself.

El Nino

We are in a very strong El Nino and such events are highly correlated with warm winter temperatures and poor snowpack over the region.  Sea surface temperatures have been about 2C above normal over the past two months (see below).  

According to NOAA/NWS, El Nino years are associated with warmer than normal October-November-Decembers (see below for a local climate division)

And snowfall is less than normal over our region for El Nino autumn periods (see below, brown colors)

The warmth and low snowpack over the Northwest during El Nino years are produced by enhanced low pressure over the eastern Pacific and high pressure to the northeast of our region.    The observed pattern for November 1-December 27th this year at 500 hPa (about 18,000 ft) is just like that.

El Nino is clearly a major driver of our anomalous warmth and low snowpack, something not mentioned in the article.

But there is another check on the Seattle Times/NY Times climate-change origin of the low snowpack.

If climate change was the origin, there would be a progressive loss of snowpack over the region as the planet warmed. 

This is something we can check.   Below is a plot of the water content in the NW snowpack on April 1 for the past few decades (1984-2023), courtesy of past Washington State Climatologist, Mark Albright.  The linear trendline is also on there (black/brown line).

Lots of ups and downs, but no trend.   Thus, climate change is not causing a significant long-term decline in our snowpack.   

An independent check on these numbers is to determine when the mountain snowpack has melted out.  Clearly, with less snowpack, the snow would melt out sooner.    Below is the date of the melt-out at Steven Pass (around 4000 ft).

If anything it has gotten later.

Now don’t get me wrong.  The planet is slowly warming.   Human emissions are a part of that.  And this will contribute to reduced snowpack over the long term.  But currently, the impacts of global warming on Northwest snowpack are quite small.

Suggestions that our greatly reduced snowpack this year is due to climate change are clearly false.

It is a shame that the national newspaper on record (the NY Times) and our local paper (the Seattle Times) can’t investigate the situation sufficiently to get the story right.

Their readers are being poorly informed.

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Before I forget, Happy New Year to all.   If anyone missed my ATMS 101 class and would like to take a similar class by an excellent colleague of mind (Professor Greg Hakim), you can take it online or in person during the upcoming quarter.    And if you are over 60 you can take it for little cost using the UW Access program

Is Much of Washington State Experiencing Severe and Extreme Drought?

From The Cliff Mass Weather Blog

Cliff Mass

It is very unfortunate when government entities provide information that is incorrect and exaggerated.

Misinformation made worse by the willing repetition by click-hungry media.

There are few better examples of the dissemination of exaggerated and inaccurate information than the drought claims of the U.S. Drought Monitor, the combined effort of several U.S. Federal agencies.

The latest Drought Monitor graphic for Washington shows SEVERE DROUGHT over much of western Washington and southeastern Washington (see below).

And EXTREME DROUGHT over the western slopes of central and northern Cascades and extending into Bellingham.

To put it politely, this graphic is silly and totally exaggerates the situation.  

To quote from the National Weather Service’s official drought webpage:

a drought is a period of unusually persistent dry weather that persists long enough to cause serious problems such as crop damage and/or water supply shortages.

An EXTREME DROUGHT would be expected to have devastating impacts.

The current situation is very different.  A drier than normal past year for sure, but plenty of water for nearly all needs.   Few impacts.  Plenty of water for human consumption.

Let’s explore the current situation with real data.  The current streamflow is shown below.  Most locations observe near-normal streamflow,  including in the “Extreme Drought” area along the western slopes of the Cascades.  As many above-normal streamflows as below.   Looks pretty normal to me!

What about water supply?  Is there a lack of water in the reservoirs for our use?   Take a look at Chester Mores Lake, the main water reservoir for Seattle, over the past year.  The levels are down from earlier in the summer, but similar or higher than last year in early fall.   Plenty of water for human consumption.

None of the major cities in the region have any problem with sufficient water supplies for its population.  For example, Tacoma’s supply is green (ample):

Tacoma Washington Water Supply

Everett’s water supply outlook indicates sufficient water:

What about agriculture?  With all the drought going around you would expect poor crops.

But that is not what happened.   

The apple crop, the biggest of our state, is way up:

The grape crop?  It was knocked back by a cool, wet spring (no drought) and the expectations are for smaller crop (down perhaps 20%), but the warm/dry summer (perfect growing conditions) is expected to produce an excellent vintage for many varietals.

The Water Year Precipitation

To get a better idea of how serious the current water situation is, let’s take a look at the historical rainfall.  The water year runs from October 1 to October 1 and is perfect for examining the situation today.

Here is the plot of water year rainfall at Olympia going back to the 1940s.  A green line smooths out the year-to-year variability.  This year is on the low side, but certainly, many years have been lower.  Little long-term trend is apparent.

Yakima had a very close-to-normal year.

Spokane was near normal as well.

The historically driest location this year was Hoquiam, located on the very wet Washington coast.   Have not heard many complaints from folks in that region.

Finally, the precipitation at Seattle’s Tolt Reservoir was near normal historically.

Do these actual numbers suggest extreme drought?  Finally, what about snowpack?  The end-of-spring snowpack this year was well above normal, providing a huge amount of water for all uses!

The Bottom Line is that the last year was drier than normal in terms of total rainfall for several locations.  But it was well within normal variability and there was still plenty of water for human consumption and most agriculture.

To call the situation a severe or extreme drought is simply deceptive and wrong.  It is counterproductive in many ways and undercuts the confidence of citizens and local agencies.  The Drought Monitor graphic is done subjectively and is a real roadblock for rational decision-making.

Let me note that there is no basis for predictions of a dry fall.   September was much wetter than normal and forecasts call for bountiful precipitation (see forecast for the next two weeks from the European Center ensemble system).  Looks moist to me.    El Nino years CAN have wet falls.

Crying wolf has never been a good approach.

The Big Chill will Save California From the Big Melt

The reason:  a deep trough, low-pressure area, not unlike some of the features seen for much of the late winter.

From Cliff Mass Weather Blog

Cliff Mass

The media has been going big on potential disasters in California.

Drought warmings earlier this winter have been replaced by scary warming of major flooding as an incipient  “Big Melt” rapidly melts the record-breaking snowpack over the Golden State.

Desperately, California reservoir managers have been dumping water in a race to prevent reservoirs from being overtopped and potentially damaged as temperatures warm.

But it now appears that the weather gods have decided to be kind, and meteorological salvation is now in California’s future.

An incipient Big Chill is about to reduce the Big Melt to tolerable levels.

Using the European Center ensemble prediction system, the best in the world, here are the predicted differences from normal of surface air temperatures around California for the next week.  This is also called the anomaly from climatology.

Blue indicates colder than normal;  green is much colder than normal (by 8°F or more).

Wow.   Lots of green over the entire state.  The mountains above LA will be frigid.

Consider Truckee Airport at 5600 ft in the Sierra Nevada range (see below).  No heatwave there, with temperatures most nights dropping into the 20s and many days only getting into the lower 40s.

The National Weather Service’s extended temperature forecast for the entire month of May from their GFS model is for substantially cooler than normal over California.

And did I mention that Pacific Ocean sea surface temperatures along the West Coast are MUCH colder than normal?  See below.  Blue colors indicate below-normal ocean temps.

In short, such suppressed temperatures will be California’s near-term future and will greatly decrease snowmelt.

This is going to be one of the coolest Mays in California history if the models are correct. 

So let’s give this a name:  The California Big Chill.

I know your next question.  Why is California going to be SO COLD during the next week or so?

The reason:  a deep trough, low-pressure area, not unlike some of the features seen for much of the late winter.

Below is the upper-level map for 2 PM Wednesday.  The solid lines show the heights of 500 hPa pressure (you can think of this as the pressure around 18,000 ft) and the shading is the difference from normal of these heights/pressures.

An unbelievably strong low off California.  Very unusual for this time of the year.

This low sticks around for a few days and then ANOTHER strong low begins to move in from the Northwest on Monday (see below).

A cool May will allow the Sierra Nevada snowpack to slowly melt.  Reservoirs will fill but not overtop.  Flooding will be lessened.

Bottom line:  it appears that California will get through this unusually wet/snowy period without serious flooding.

But one thing is clear:  the political “leadership” in California has been deeply irresponsible during the past decades by not adding more reservoir capacity.   No new reservoirs have come online in the Golden State during the past 40 years, as the population has doubled. 

More reservoirs would not only have promoted safety by holding all the wet bounty for slow release, but would make huge water resources available for the growing population and agriculture in the State.  

There is too much talk about global warming and not enough rational planning and action to deal with the known environmental challenges of the state.

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The Northwest Weather Workshop agenda and information are online.   This meeting, which will take place on May 12-13th in Seattle, is the major weather meeting of the year in the Northwest.   We have a varied and interesting agenda.  The meeting is open to everyone and if you want to attend you must register (on the website).   

We will also have a banquet/talk at Ivar’s Salmon House on Friday May, 12.  This is a fun meeting and will be hybrid (in person and on zoom).