July 04, 2025

July 4 Weather and Fire Threat

 July Fourth is the most wildfire-prone day of the year, with a massive number of human ignition sources spread across the region.  So please be careful.

Today, Washington will be relatively dry, but eastern Oregon will have some natural fireworks from several thunderstorms.

The current (Friday at 8 AM) radar image shows the rain from the thunderstorms over Oregon (below).


With the lightning strike map at 8 AM indicating a number of strikes at that time (red crosses)


The UW WRF model predicts that the main shower area will move to northern Oregon and Idaho by mid-afternoon.


Why showers over Oregon?  Because of an upper-level trough/low pressure moving through southern Oregon and northern California.

The biggest wildfire threat today is from fireworks igniting dry grass and light vegetation. 

 Below is the map (from USDA Fuelcast) of dry fuel amounts over the region. Plenty of fuel over eastern Washington and Oregon.



And, in fact, there are some grass fires burning now, such as the Apple Acres fire near Wenatchee and the Cold Springs fire south of the Tri-Cities. 


The biggest threat will be where there are both strong winds and dry fuels.   

Below are the forecast surface winds around 8 PM tonight.  As expected, the strongest winds are on the eastern slopes of the Cascades, descending into eastern Washington and Oregon.  

This is where folks will have to be very, very careful


Another threat is from lightning-initiated fires over eastern Oregon, something that happened last year.

In short, be careful today and enjoy the 4th.


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3 comments:

  1. FriendJuly 4, 2025 at 11:20 AM

    It was a rather chilly morning in the Bellingham area this Independence Day. I observed a morning minimum temperature of 48.4F at my location - the lowest July temperature since 2020. KBLI appears to have observed a low of 46F - the lowest July temperature since 2019 if verified.

    ReplyDelete
  2. FriendJuly 4, 2025 at 11:32 AM

    In fact, if verified, the 46F low temperature at KBLI would be the 3rd coldest Independence Day daily minimum temperature on record for the location.

    ReplyDelete
  3. John F. HultquistJuly 4, 2025 at 1:05 PM

    If you focus in on the USDA Fuelcast map the irrigated Kittitas Valley (red) shows in the center. The white area near the center is where Ellensburg is. No doubt there is fuel here - - much grass and alfalfa hay. The first cutting is already in storage.
    Within this area are fuel-ladened riparian zones. Over the past 75 (?) years these areas have large trees (some dying of old age) and dense brush – see this site under Overbank Zone. https://www.nrcs.usda.gov/plantmaterials/wapmstn13160.pdf
    My house is just 100 feet downwind of this zone. Cutting the vegetation back is a yearly task – growth is relentless.
    If I have correctly identified the red area, it is misleading. The real fire danger is on the mostly unoccupied hills north and south of the red area. The Snag Canyon (2014) and the Taylor Bridge (2012) fires are examples.

    ReplyDelete

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July 4 Weather and Fire Threat

 July Fourth is the most wildfire-prone day of the year, with a massive number of human ignition sources spread across the region.  So pleas...