Large fire activity picked up over the weekend, especially in the Southwest and Alaska areas. Currently the 30 active, large fires across five states have burned more than 65,000 acres bringing the total for the year to 550k, well below average for this time of year. This week could increase that total as high pressure is approaching the West Coast and will provide a warming and drying trend for most of the southern West. Breezy westerly winds are expected across Arizona and New Mexico and strong northeasterly winds with some of the lowest RH readings of the year across California. In tandem, the conditions will lead to elevated and critical fire weather concern (including red flag warnings) in many places.
This past weekend, from Saturday into Monday morning, much of the Northern California Bay Area was under a Red Flag Warning due to strong winds around 40 mph with gusts to 60 mph. Despite much of the country receiving some level of precipitation recently, California remains just above the drought threshold. The gusty winds and dry fuels the state sees every fall leads to heightened fire weather conditions this time of year. Fortunately, with this strongest wind event thus far this Fall, fire agencies across the region responded rapidly and en masse to any new reports of ignition.
“Of the twenty most destructive wildfires in CA history, eleven of them have happened in October and another three in November or December.”
Transitioning out of Western Fire Season
Most of the Western fire season began the seasonal transition out of its peak in early September with fall’s cooler temperatures and precipitation. October and November mark another transition as the focus typically shifts to California where fire activity remains a major concern with summer-dried fuels and occasional Foehn wind events develop across California until winter rains come.
Brief Look Back to October 2017
Monday, October 8th, marked one year since 21 major wildfires started across Northern California and devastated the Napa-Sonoma area. Collectively the fires burned more than 245,000 acres over the course of the month. The Northern California Firestorm, as it came to be called, destroyed nearly 9,000 structures and was responsible for 44 civilian fatalities and caused 14.5 billion dollars in damages.
The fire spread was remarkable as ember showers spread from house to house throughout several communities and the fires moved at record-setting speeds. Gusting and strong winds were an instrumental driving force behind the massive levels of damage caused by the conflagrations. What wasn’t record setting was this type of fire weather happening in October or later in California. As the table below shows, of the twenty most destructive wildfires in CA history, eleven of them have happened in October and another three in November or December.
Obviously all that late season activity means, historically, the Western Fire Season is far from over in California. Fire Departments remain at full staffing, on the ready, with ears perked to every new start that could be the next big one…especially with the fire weather possibilities this time of year. RedZone does the same, and those of you in the insurance world reading this, so too should you. Those 14 wildfires have collectively caused tens of billions of dollars in damage over the years.
Red Flag Warning Possible through Saturday
The National Weather Service has issued a Red Flag Warning for Southern California beginning in the early AM hours on Monday through (at least) Friday 1200 PDT. The areas will experience a significant Santa Ana conditions with the strongest winds expected Monday night and Thursday night into Friday. Offshore winds will exacerbate the problem by drying the air and reducing humidity to the single digits. This will likely be the strongest and longest Santa Ana event we have seen in the 2017 season.
Around this time two years ago we discussed what the thresholds are for a Red Flag Warning in Southern California. In this case, the National Weather Service sees the region’s relative humidity ≤15%, with sustained winds ≥ 25 mph and/or frequent gusts ≥ 35 mph (duration of 6 hours or more). The early event projections have even stated this could extend into next weekend. Specifically, wildfire danger will be most critical in the mountains and valleys of Los Angeles and Ventura counties. The combination of Santa Ana winds, low humidity, warm temperatures, and dry fuels will increase the risk for the rapid spread of any new fire starts. In response for this week, extra strike teams, and brush engines have been strategically staged in case of a big wildfire ignition.
Areas Impacted by Santa Ana Conditions:
Ventura County Mountains, Orange County, Los Padres National Forest, Los Angeles County Mountains, Angeles National Forest, Santa Clarita Valley, Cleveland National Forest, and San Diego County.
Click for official Santa Ana Conditions information: Red Flag Warning
Santa Barbara area expecting Sundowner Winds with Red Flag
The National Weather Service has issued a Red Flag Warning for the Santa Barbara County Mountains and South Coast region for Thursday from 0900 hours through Saturday 1000 hours PDT. The area will see sundowner winds gusting up to 40 mph and relative humidity as low as 10%. These conditions, combined with temperatures reaching into the mid 90’s in the afternoons and 100’s in isolated locations, may contribute to explosive fire behavior. The regions most at risk are the foothills and through the passes and canyons.
A sundowner wind is an offshore northerly Foehn wind that occurs near Santa Barbara, California. The winds surface when a ridge of high pressure is directly north of the area, and they blow with greatest force when the pressure gradient is perpendicular to the axis of the Santa Ynez Mountains which rise directly behind Santa Barbara. These winds often precede Santa Ana events by a day or two, as it is normal for high-pressure areas to migrate east, causing the pressure gradients to shift to the northeast.
Significant Santa Barbara Sundowner Events
Sundowner winds are dried and heated by the warm inland valleys and deserts. As narrow canyons and valleys compress the winds, they become stronger and overpower the diurnal winds. Firefighting efforts during a sundowner wind event can become extremely dangerous as well as difficult. Three significant fires in the last three decades have resulted in part because of sundowner conditions.
- The Jesusita fire in May 2009 burned 8,733 acres and destroyed 80 homes while damaging 15 more. Most of the destruction occurred while sundowner winds pushed the main fire through populated areas.
- The Painted Cave Fire during June 1990 rapidly grew to 5,000 acres, destroying 427 buildings and killing 1 civilian.
- The Sherpa Fire grew to 4,000 acres overnight due to the sundowner winds, damaging the water system for El Capitán State Beach in the middle of June of last fire season.
Sources: Wikipedia, NIFC Fire history, LA Times, KEYT Santa Barbara
The Trail Fire started Sunday afternoon, March 5th, in West Miami-Dade County, FL, and quickly blanketed the surrounding area with heavy smoke. The fire prompted the closure of Southwest 8th Street between Southwest 137th Avenue and Krome Avenue due to lack of visibility in the area. As of Sunday night, Miami-Dade Fire Rescue reported that the road was back open.
Extra units remain on scene due to the potential for strong and gusty winds coupled with dropping humidity in the area. As of Monday morning, March 6th, the fire had grown to 1,065 acres with 50% containment reported. The Florida Fire Service feels confident they are gaining the upper hand on the Trail Fire. At this time, the cause of the fire remains unknown.
Trail Fire Area Weather Outlook
Much of Southern Florida is presently under a Red Flag Warning through midnight EST Monday, March 6th. Over the next few days, the area will experience strong winds out of the east with gusts over 30 mph at times. Also, local relative humidity levels will steadily increase through the end of the week, with 20-40% chances of rain showers.
For current weather at the fire’s location, please visit Weather Underground.
This is an ongoing incident. Please visit the news links below for further details and the most up to date information regarding this fire. RedZone will continue to update this post if relevant information becomes available.
Early this week the National Weather Service (NWS) indicated that conditions in the Southern Plains may evolve into a significant fire weather event. Specifically, The National Weather Service issued a Red Flag Warning on Monday (2/6) for an area encompassing the Southeastern Colorado Plains through Oklahoma, New Mexico, and Texas. A fire weather watch is also in effect for South Central Texas through Tuesday (2/7).
A Pacific Jet Stream moving through the area resulted in critical to near-critical fire weather conditions for the Region. According to forecasters, particularly strong winds coupled with low relative humidity and the current dry fuel situation amplified the potential for extreme fire behavior. Tuesday (2/7) should bring more of the same as the Pacific Jet Stream moves east through the area. It’s likely that the current warning, set to expire this evening (2/6) at 1700 hours, could be reinstated for at least some of the region tomorrow should conditions persist.
Southern Plains Fire Activity
Dry and windy fire conditions were evident this past weekend as active fires burned across Texas, Oklahoma, and even Colorado. In Elbert County, CO, a rare winter fire scorched nearly five hundred-acres. Residents were given notice to evacuate as the fire approached the aptly-named Chaparral Subdivision. Six or seven homes were briefly threatened as seven fire crews scrambled to get a handle on it. The fire was called contained at 1900 hours Saturday. In order to ensure control, crews stayed behind to patrol the blackened perimeter overnight.
Concern in Southern Plains Predicted
Above normal significant wildfire potential is expected for the Southern Plains for not just early this week, but for at least the next two months. This month’s recently published wildfire outlook, a report from Predictive Services (NIFC), suggested that any prolonged periods of dry and windy conditions in the Southern Plains could “provide opportunities for any ignitions to become significant fires.” The report further stated that last year’s precipitation totals in the region have brought about a somewhat robust fine fuel crop. The excess fine fuel could increase fire activity and likely warrant extra attention for the area when dry and windy conditions are forecasted, as were seeing this week.
NIFC Predictive Services, ABC 7 Denver, National Weather Service