The Bear Gulch Fire is still burning on the southeast side in the Olympics and has increased to about 4700 acres.
Its location, on the southeast side of the Olympics, is a meteorologically favored one for wildfire.
Consider a map of the historical fires around the Olympics (below).
Most fires occur to the northeast, east, and southeast of the Olympics. You will also note that the biggest fires (largest dots) are clustered on the southwest side of the barrier. The recent Bear Gulch Fire is in the middle of this "favored" area.
Why? Because this is in a rainshadow area downstream of the Olympics, an area much drier than the rainforest region on the western slopes.
I can demonstrate this by showing the average annual rainfall for the area (below). While the western side has some of the greatest yearly totals in the U.S., with some locations receiving over 150 inches a year, the eastern side enjoys "only" 60-80 inches. The western side is much cooler during the summer, and is often flooded by marine clouds and drizzle.
Another contributing factor to fire growth in this area is the steep terrain slopes on the eastern side of the Olympics (see the topographic map below). Fire growth is enhanced on slopes, as heated air and fire move upwards. It is also far more difficult to fight fires in steep terrain.
The unusually dry summer has certainly contributed to the fire potential this year.
There is some good news about the current fire: significant rain and cooler temperatures are arriving this week.
Below is the latest model forecast of accumulated precipitation through Thursday at 5 PM. The Olympic Mountains are going to be hit fairly hard with precipitation, with a good wetting over the Bear Gulch Fire.
Should give fire crews real aid in getting this fire restrained.
Cliff - I’ve spent considerable time in the Olympics and have spend a lot of time in the winter chasing the “blue spot”. The blue spot is usually between Deer Park and Townsend. I think the precip map you are showing is based on data that doesn’t take into account how much more rain the staircase area receives compared to the NE corner of the Olympics (Baldy/Tyler/Townsend). I suspect the cluster of bigger fires in the SE corner are a combination of enough rain for denser tree growth than the NE area and more human use outside of the park (dispersed camp fires and logging).
ReplyDeleteLet's hope the rain helps. I recently sat out a major downpour in Ontario. There was a fire in the fire pit that was burning pretty good when the storm hit. I was impressed/surprised by how tenacious the fire was in spite of the major rain storm. It will take a lot of rain to knock down that fire, but every bit helps I suppose. Fingers crossed.
ReplyDeleteOn the other hand a hard rain can really knock down a fire. I was camping in the Rockies once when a T-storm came up and it rained hard for ~20 minutes. It completely extinguished my campfire.
DeleteProfessor Mass,
ReplyDeleteThank you for sharing this insight about the Olympics and their meterological vulnerability to fire. It is great to see a spotlight being shined on this, given the current situation with the Bear Gulch fire.
I noticed that the map of the Olympic National Park's fire history that you shared only goes up to 2006. Is a more current map of the area's fire history available, and, if so, are there any significant deviations from the map you shared? For instance, has the west side of the Olympics seen an increase in large fires?