Fire season could stay dangerous into November, experts predict

 
01 August 2017

published by http://www.redlandsdailyfacts.com


USA - In a report that makes last spring’s end to the drought seem like a distant memory, fire officials say anything that could fuel a devastating brush fire in Southern California is quickly drying out and that residents should have their evacuation plans in place.

“This has already been a busy fire season, and it has the potential to continue to be a busy fire season into November,” said Tom Rolinski, a meteorologist with the U.S. Forest Service. “The big wild card is, how much Santa Ana winds are we going to get before we get any meaningful rainfall?”

Those winds, which blow west from the desert, can sap any remaining moisture from vegetation and push flames faster than firefighters can move. They typically start to show up in September and are most active from October through February.

Forecasters including Rolinski in the multi-agency Geographic Area Coordination Center issued their latest three-month seasonal outlook on Tuesday, Aug. 1.

“This fall may be one of the more active and dangerous seasons in years due to the high amount of fuel loading from last winter’s rains and the remnant stands of dead vegetation,” the report concludes.

There’s a bumper crop of grasses this year because of the rains that ended the drought, and the grass is expected to reach “critical dryness” by the end of August, the report said.

The hot weather that cooked Southern California in June continued through most of July, with temperatures 4-6 degrees above normal. And there was less monsoonal moisture than usual in July. That hot, dry weather has caused both “fine” and “heavy” fuels to dry to near-record low levels.

“The heavier fuels are at the point where they are going to support heavier fire,” Rolinski said. “That’s why we are getting more fire activity.”

Through July 30 this year, Cal Fire has responded to about 30 percent more fires that have burned about 50 percent more acres than at this time last year. But that heightened activity does not necessarily mean there will be more fires through the rest of the year, Rolinski said

If residents haven’t already done so, it’s time to get evacuation plans in order, Rolinski said. Fire officials recommend visiting ReadyForWildfire.org for tips. A defensible space around a home — an area cleared of vegetation that could catch fire — should already be in place.


“It’s almost a little too late to start doing brush clearance. It’s going to be very receptive to fire, and you don’t want to do anything that can cause a spark,” Rolinski said. “Sparks from a lawnmower or weed whacker — grasses are going to be very receptive to ignition.”

Cal Fire/Riverside County Fire Department said “equipment use” touched off the Rose fire Monday near Lake Elsinore. A resident said a friend was mowing brush to fortify a defensible space when the fire started.

Tuesday’s report also issued a warning for firefighters:

“Proper use of safety protocol will be critical when engaged with the hostile fuel and weather conditions expected the next several months,” forecasters cautioned.

FIRE WEATHER HIGHLIGHTS

• Above-normal temperatures through the summer and fall.

• Near- to slightly below-normal summer monsoonal thunderstorm activity.

• Large fire (300 acres+) potential will be well above normal across most areas outside the desert and irrigated areas into the fall.

• Live fuels becoming critically dry over Southern California by early to mid-August and in September across Central California.

Source: National Interagency Fire Center outlook, August-November

BRUSH FIRES RESPONDED TO BY CAL FIRE

For the period of Jan. 1 to July 30.

• 2017: 3,736 fires that burned 206,062 acres

• 2016: 2,860 fires that burned 139,014 acres

• Five-year average: 3,024 fires that burned 83,931 acres

Source: Cal Fire

An international team of climate researchers from the US, South Korea and the UK has developed a new wildfire and drought prediction model for southwestern North America. Extending far beyond the current seasonal forecast, this study published in the journal Scientific Reports could benefit the economies with a variety of applications in agriculture, water management and forestry.

Over the past 15 years, California and neighboring regions have experienced heightened conditions and an increase in numbers with considerable impacts on human livelihoods, agriculture, and terrestrial ecosystems. This new research shows that in addition to a discernible contribution from natural forcings and human-induced global warming, the large-scale difference between Atlantic and Pacific ocean temperatures plays a fundamental role in causing droughts, and enhancing wildfire risks.

"Our results document that a combination of processes is at work. Through an ensemble modeling approach, we were able to show that without anthropogenic effects, the droughts in the southwestern United States would have been less severe," says co-author Axel Timmermann, Director of the newly founded IBS Center for Climate Physics, within the Institute for Basics Science (IBS), and Distinguished Professor at Pusan National University in South Korea. "By prescribing the effects of man-made climate change and observed global ocean temperatures, our model can reproduce the observed shifts in weather patterns and wildfire occurrences."



Read more at: https://phys.org/news/2017-07-atlanticpacific-ocean-temperature-difference-fuels.html#jCp
An international team of climate researchers from the US, South Korea and the UK has developed a new wildfire and drought prediction model for southwestern North America. Extending far beyond the current seasonal forecast, this study published in the journal Scientific Reports could benefit the economies with a variety of applications in agriculture, water management and forestry.
 

Over the past 15 years, California and neighboring regions have experienced heightened conditions and an increase in numbers with considerable impacts on human livelihoods, agriculture, and terrestrial ecosystems. This new research shows that in addition to a discernible contribution from natural forcings and human-induced global warming, the large-scale difference between Atlantic and Pacific ocean temperatures plays a fundamental role in causing droughts, and enhancing wildfire risks.

"Our results document that a combination of processes is at work. Through an ensemble modeling approach, we were able to show that without anthropogenic effects, the droughts in the southwestern United States would have been less severe," says co-author Axel Timmermann, Director of the newly founded IBS Center for Climate Physics, within the Institute for Basics Science (IBS), and Distinguished Professor at Pusan National University in South Korea. "By prescribing the effects of man-made climate change and observed global ocean temperatures, our model can reproduce the observed shifts in weather patterns and wildfire occurrences."



Read more at: https://phys.org/news/2017-07-atlanticpacific-ocean-temperature-difference-fuels.html#jCp