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:
__________________________________________________________________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.
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:
Climate Lab is cherry picking reporting and keeping the clicks coming.
ReplyDeleteThe climate nuts will also claim lots of snow leads to more vegetation and more fires
ReplyDeleteVegetation does require water to grow. The more water it gets, the more it tends to grow. This doesn't apply to all vegetation of course, but it does apply to quite a bit of what grows around here. But more vegetation doesn't automatically mean more fires. It does mean that there is more fuel available for the fires that do ignite, however.
DeleteIf we are just eyeing the charts, when I look at the snowpack-wildfire chart it appears that when the snowpack drops below 35 inches, the subsequent year has a significant increase in wildfire acreage over the prior year or two. 2015 not fitting the pattern as it was an unusual year as described by Cliff.
ReplyDeleteA note on snowpack, elevations above 5,500 ft hold more than half of this store of water. I wonder what the picture is when snowpack and water in reservoirs are analyzed on a watershed by watershed basis and then if you split out grass fire acreage vs forest fire acreage. Does greater snowpack lead to greater grassland fire acreage where it does not for forrest fire acreage?
Agree with Cliff that lack of snow is not as important a factor as other factors in determining what the coming fire season loss will be. Since acres burned for Washington is usually determined by the nature of fires east of the Cascades, it is the weather and fuel factors on that side of the Cascades that will likely determine the amount of acres burned this season. The main factors for east of Cascade fires are the degree of heat and dryness during the late spring and summer months, and the nature of lightning storms, since dry lightning storms have been the major factor in most of our large acres-burned seasons. However, the lack of snow in the mid and higher elevation forest areas can lead to the heavier fuels in these areas drying out earlier and becoming drier than usual so forest fires, as opposed to grass fires, can be more of a problem this year versus in snowier years. Due to the heavier moisture recently, we can expect at good growth of grass this year and when this dries out, lower elevation grass fires could be a more serious problem this year also.
ReplyDeleteTo me seems like the strongest correlation to areas burned any be to wind rather than to snowpack. But how can one predict based on wind, which seems to be as variable and unpredictable as rain once was before the science of meteorology
ReplyDeleteThe science of wind prediction seems to have some room for improvement. I'm often surprised at how often the wind will kick up at the coast even when high winds are not predicted. It happens a few times a month, all year long.
DeleteFollowing fires in 2012 and 2014, an effort was started to do more to prevent fires and lessen the spread. See: https://kittitasfireready.org/what-we-do/
ReplyDelete"In May 2017, agencies, stakeholders and community members met to express concerns for wildfire related issues in Kittitas County. Recognizing the importance of the issues of fire adapted communities, the meetings continued and the Kittitas Fire Adapted Communities Coalition (KFACC) was formed."
Is the Northwest an outlier?
ReplyDeleteSnowpack decline kindles more severe fire in the western United States: ..."using remotely sensed snow and fire data spanning 1985–2021, we examined how snowpack quantity and timing of spring snowmelt influence annual area burned and burn severity at the watershed scale. Early snowmelt was associated with earlier occurrences of fire ⩾400 ha and greater annual area burned, whereas low snowpack water content was associated with more severe burn outcomes including greater mean composite burn index (CBI) and larger proportions of high severity fire (CBI ⩾ 2.25)." Environmental Research Letters Vol. 21 #6
This paper actually supports my analysis, finding little connection between snowpack and wildfire over the Pacific Northwest. Did you take the time to carefully read the paper and its supplements? You should..cliff
DeleteThis paper states that early snowmelt and low peak snow water equivalence was correlated with earlier onset of large fires, greater amount of burned acres and greater severity of the burned areas, in all regions of this study, including the Pacific Northwest. This may be the average condition over the period of the study, 1985 to 2021, but the study also stated that weather conditions during individual years, especially temperature and moisture, also influenced the acres lost to fires. I believe this to be true for Washington state, where weather conditions prevailing from late spring through summer are most often the main factors in determining the severity of the fire season.
DeleteThey did not show correlation of April 1 snowpack with toal acreage of Washington State or the Northwest.
DeleteLike to know the correlation between power lines sparking, fireworks, campers not watching campfires, etc. which probably has a far higher impact than snow packs. Seeing more fires on the west side of the mountains where snow is not a factor.
ReplyDeleteYes. Low summer precipitation and humidity are probably the biggest factors. Consider that most of the East Coast gets a foot or two of snow depth AT MOST but they have few fires.
ReplyDeleteTheir ace in the hole is humidity
but mainly summer rain, of
which they get a lot. We on the west coast don't get that, arguably the biggest problem with our climate.
Pardon my last articulated paragraph. I typed it on the phone and touch screens suck.
ReplyDelete