California and Oregon Are Getting Our Rain: But That is OK

 There is always a yin and a yang in the weather.

Because of the structure and limited extent of weather systems, one area's precipitation bounty inevitably means less precipitation than normal for an adjacent region.

This is often true on the U.S. West Coast.  When California is wet, we tend to be dry and vice versa.

In April, such a reversal of fortune is occurring, with northern California and Oregon receiving above-normal amounts, and less than normal precipitation over Washington State.

Let's start with the current water year (October 1 to now) precipitation totals (the percentage of normal is shown).

Western Washington and the Cascades are in good shape, which is why our reservoirs are full.  Southern California has been wet.  But Northern California and much of Oregon have been drier than normal.

Climatologically, precipitation tends to shift north in the spring as the moisture-transporting jet stream moves northward, leading to a drying of California, while maintaining substantial precipitation in Washington State and British Columbia.

You can see this effect in the climatological precipitation maps for the region (below).

For January, substantial precipitation (dark blue color) extends from Washington State to Northern California and down the Sierra Nevada. Even Southern California gets a piece of the wet action.

But April is different, with far more precipitation falling over the Northwest than California, with profound drying over the southern portion of the state (see below).  In May, the California lack of precipitation is even more profound

But this year, something different is happening. 

The total precipitation forecast for the next 15 days (below) is for heavier-than-normal precipitation in California, with southern Oregon getting a substantial wet bounty as well.    Washington State will get some welcome precipitation as well, but the real action will be south of us.

The folks in LA and San Diego will be startled by all the rain, but the thorough wetting of California will greatly benefit the huge agriculture industry of the Golden State.  

What is going on?  

This is not climate change, but rather the development of anomalous upper-level lows that are heading into California.  

Below are predicted upper-level (500 hPa pressure, about 18,000 ft) maps, with blue showing troughs of low pressure (which are associated with precipitation).

11 AM Monday....a deep trough over northern California.

5 PM Saturday... another CA trough

Monday, May 4?   Another low-pressure area is heading to California.

Finally, although Washington State has a dry period ahead, we received substantial precipitation last night from a wet system that dropped very heavy precipitation exactly where we needed it:   on the eastern side of the Cascades and over the mountain barrier (see 24 hr below).   

Perfect for supporting agricultural needs over the Yakima Valley region.  

The weather gods are taking care of both California and our region.😊

Will 2026 Be An Above-Normal Wildfire Year in Washington State?

Virtually every spring, some media and activists claim that the upcoming summer will bring above-normal wildfire activity over the Pacific Northwest because of global warming/climate change (see example from last year below).  

The Seattle Times Climate Lab consistently predicts above-normal fire risks

So what does real data actually say?    That will be the topic of this blog.

Let's start with actual wildfire information:  the total wildfire acreage over Washington State's WA DNR (Department of Natural Resources) lands for the last decade (see below).

You will note no upward trend.    Also note that the last few "drought"  years have had below normal wildfire area.   

If we compare the Washington State wildfire area against temperature or precipitation across the state, you will note a poor correspondence (see below).  Clearly,  other elements (e.g.,  fuel availability, wind, lightning, human ignition) are important as well.

So what about this summer?  

An important supporting element for fire is the availability of surface dry fuels (e.g., dry grasses), and there is a website (the U.S. Department of Agriculture's Fuelcast website) that has this information.

The image below shows the latest on the availability of surface fuels such as grasses and flammable vegetation (yellow is below average and green above average).   

Lower than normal over much of eastern Washington but above normal over the Cascades, including its eastern slopes.    

So good news for the lowlands of eastern Washington and the western slopes of the Cascades.  A cause for concern over the upper eastern Cascade slopes...where there was lots of vegetative production by the bountiful precipitation this year. 

The latest European Center seasonal precipitation forecasts are a mixed bag.  For April/May/June, predicts drier than normal conditions over western Washington and the Cascades, fostering a drying of vegetation and surface debris.

On the other hand, it is predicted to be wetter than normal conditions for the critical July to September period when most of our fires occur.

For temperature, the EC prediction is for warmer-than-normal temperatures (see below), which contributes to drying.

But as shown earlier, temperature and precipitation are only part of the story for local wildfires.

Lightning is critical, particularly since it often ignites fire in remote areas.  

Strong winds are essential for the biggest fires, contributing to ignition and rapidly spreading the flames. 

Human ignition is important, and that depends in part on the willingness of utilities to maintain lines and de-energize when advisable.   

Fuel availability is significant, and we have a good idea now of the vulnerable areas (eastern slopes of the Cascades).

To put it concisely,  a simple argument that global warming causes more fires is simplistic and generally wrong, and a more nuanced and data-driven analysis is critical.