Near term wildfire forecast remains below average

Cal Fire’s Southern Operations Unit issued its latest Wildfire Outlook
last week. From now through early summer, wildfire conditions are likely
to remain lower than normal. However, as the Pacific weather conditions
continue to shift from El Niño toward a La Niña pattern, the chances of
large wildfires begin to increase.

Both live fuel moisture and dead fuel moisture continue to remain above
average. While this winter’s precipitation was not as great as in 2023,
it has been sufficient to maintain higher fuel moisture levels.
Consequently, South Ops forecasts the odds of a large wildfire season to
be below normal through July.

In April, the National Weather Service’s Climate Prediction Center
reported that the current El Niño conditions were fading quickly. It
predicted neutral conditions will arrive in May or June.

But by summer, a 60% chance of La Niña conditions will arrive and affect
Southern California weather through fall, which means it will be warmer
and drier. Based on summer 2022, it could be significantly warmer.

The presence of La Niña conditions combined with a probably larger fuel
presence due the winter precipitation slightly tilts the odds toward a
“normal large fire potential rather than below normal for August,”
according to South Ops.

Dr. Daniel Swain, meteorologist and climate scientist at the Institute
of the Environment and Sustainability at the University of California,
Los Angeles, concurs in this view. In his mid-April report, he wrote,
“The combination of lots of recent vegetation growth (including in some
of the large burn areas from the past decade, which will increasingly
support re-burns), plus a fairly high likelihood of a hotter and perhaps
also drier than-recent-average end to summer and autumn right when
offshore wind seasons starts, indicates to me that this California fire
season could end very differently than it begins.”

While the West has been wet and experienced lower than normal fire, the
Continental U.S. was different. Although fire activity in the Eastern
and Southern areas decreased, year-to-date annual acres burned for the
U.S. is well above the 10-year average at 240% of normal. In all of
2023, 2.7 million acres were burned from wildfires. Through the end of
April, 1.8 million acres have been burned. The late February fire
outbreak in the panhandles of Texas and Oklahoma burned over a million
acres which was very unusual. But the total number of wildfires is 76%
below average number through April.