By Kimberly Arsenault
Contributor, EDM Digest
Officials from the National Interagency Fire Center say the threat of wildfires is likely to remain high, possibly through November, for southern California and northern Nevada, due to severely dry conditions, while the fire threat for parts of the Northwest and the northern Great Plains will remain high throughout August due to existing drought conditions. Fire officials also indicate that the fire risk remains high on Hawaii’s Big Island and in northern Wyoming.
Thick grasses, spawned by a wet winter with record snowfall amounts that melted amid higher than normal June temperatures, led to dry conditions that began to increase wildfire risks, including those from lightning strikes. The recent high-heat, some of which set records, has increasingly parched areas throughout the west, pushing fire danger even higher.
Dry Conditions and Fuel Loading
Another report from the Geographic Area Coordination Center concluded that due to current conditions, “this fall may be one of the most active and dangerous seasons in years due to the high amount of fuel loading from last winter’s rains.”
Dead fuels, including both ‘fine’ and ‘heavy’ fuels, are being pushed uniformly to near-record dry levels, while bug-killed timber has also increased the available fuel loads, most considerably in the Sierra Nevada foothills. Fine fuels include smaller twigs and grasses, while heavy fuels encompass larger limbs and logs, including living trees, where moisture readings are expected to drop to critical dryness levels by the end of August in the predicted danger areas.
“This fall may be one of the most active and dangerous seasons in years due to the high amount of fuel loading from last winter’s rains. ~ Geographic Area Coordination Center, Southern California.”
Southern California’s Santa Ana Winds
For California, the Santa Ana winds that show up sometime in September and last at least through March, also play a factor in the fire season threat because these down-slope winds compress, dropping the humidity level in the air and raising its temperature quickly, thereby increasing the wind speed–which drives this hot air towards the coast. Since the air is also forced to squeeze through narrow passes and canyons, its speed further increases, causing the Santa Ana winds to reach speeds in excess of 40 k/mh with gusts that can be considerably higher, especially at upper elevations. The quickly moving hot air further removes any remaining moisture from area vegetation, which has been plentiful this year due to heavy rainfalls that encouraged the growth of grasses.
As a result of the current fire risk dangers, fire fighters are being cautioned to follow all safety protocols, including LCES, when engaging with high risk fires due to hostile weather conditions and fuel loads.
2017 Wildfire Statistics
This year to date, there have been 39,000 total wildfires that have consumed over 5.49 million acres, with 36 active fires burning in 9 states. The states with the highest number of active fires include Montana (11), California (9), Oregon (6), and Washington (3).