Discussion: Red Flag Warnings are in effect for parts of Southern California as fire weather conditions reach critical levels throughout the weekend into Monday afternoon. A moderate to locally strong Santa Ana wind event has developed over the area. These winds combined with the near record temperatures in the mid 80s, low relative humidity values, and dry vegetation will bring elevated conditions to the mountains and valleys in both Los Angeles and Ventura County. Gusty winds were expected to start around 10 PM PST Saturday and are expected to last through Monday afternoon. A red flag warning is issued when the weather conditions may indicate a period of weather that could lead to extreme burning conditions. During this time, it is important to heed local burn bans, properly discard any cigarettes, and avoid activities that cause open flames or sparks. With the dry vegetation, warm temperatures, gusty winds, and low humidity it doesn’t take much to spark a wildfire!
Santa Ana winds are most often characterized as being hot/dry winds which blow in from the desert towards the coast. These winds tend to occur during the following time frame (between September and May) when the desert is cooler than the Los Angeles basin. To learn more about fire weather and fire weather education, be sure to click here!
© 2018 Meteorologist Shannon Scully
In a particularly calamitous year for natural disasters across the United States, wildfires continue to burn in California past the normal fire weather season. A new solution to arm fire weather officials, led by researchers at the University of Wyoming, hopes to model wildfire growth in an effort to close a 12-hour information gap provided by NASA's Active Fire dataset.
While the Active Fire dataset (collected from the Moderate Resolution Imaging Spectroradiometer instrument on board NASA's Aqua and Terra satellites) provides a high-resolution snapshot of the burning wildfires, it suffers temporally. According to the researchers, the more readily available that updates about the wildfire's behavior or change in growth are, the more informed fire management officials can be when making critical decisions, such as mass evacuations.
Researchers at the University of Wyoming developed a computer model to simulate fire growth and spread on the scale of minutes based on factors such as fuel moisture, land topography, and real-time weather. Preliminary results were shared with fellow scientists at the American Geophysical Union Fall Meeting in New Orleans last December.
In the results, the model was compared to NASA's Visible Infrared Imaging Radiometer Satellite data in three different wildfires that occurred in Wyoming and Montana in 2017; while the model tended to over-predict the fire area, it did predict more than 86% of the actual burning area.
According to scientists at the American Geophysical Union who attended the preliminary results session, the model looks incredibly promising. The researchers at the University of Wyoming plan to continue their investigations in an effort to improve their model by looking at the California wildfires in 2018.
Check out the full press release from the AGU here, or read more about fire weather on our site here.
© 2018 Meteorologist Chris Stubenrauch
Wildfires are nightmarish scenarios that have become a reality for many people not only in California but also across the globe. These catastrophic events not only threaten life and property but also within a blink of an eye can grow out of control. Bringing about new dangers outside of the fire itself.
An example of bizarre behavior within a wildfire was brought to public attention via a home recording from Portugal. The short clip depicts a scene that has seemingly been taken out of the newest Hollywood disaster flick. An out of control wildfire is seen ravaging the countryside coupled with what appears to be a tornado that is on fire. The title of the video was “Portugal Fire tornado”. But what exactly is a “Fire Tornado”? Further research into the subject reveals that the so-called ‘Fire Tornado’, is a misnomer. The video from Portugal captured what is actually known as a fire whirl. A fire whirl is defined as a cyclone, or whirlwind induced by fire and is comprised of flame debris or ash. The fire whirl, commonly dubbed fire tornado, fire devil, or firenado, results when air at the surface is heated, loses density and begins to rise. The rising air leaves an open space for cooler air to rush in. The newer cooler air becomes heated and rises, and the cycle continues and each rising thermal contains a combination of ash, fire, and debris. The vorticity or spin of the rising air will “tighten up” into the recognizable funnel shape, similar to when you drain a bathtub. These fire whirls are unpredictable and extremely dangerous for first responders attempting to extinguish the inferno.
However, fire whirls are not technically considered to be a meteorological event. Conversely, some wildfires can become so expansive and release enough energy that they generate their own wind systems and form what is known as a firestorm. Firestorms are not exclusively produced from wildfires, but can also result from aerial bombings and explosives. Because these firestorms have their own wind systems, they can manufacture weather systems. When the heat and moisture from the fire rise into the atmosphere a pyro-cumulonimbus cloud can form. These marvels behave the same as regular cumulonimbus clouds but the fact that pyro-cumulonimbus clouds do not exist outside of the above conditions is a key distinction between the two.
Pyro-cumulonimbus clouds have been known to yield thunder, lightning, hail, and rain. In January of 2003, a severe bushfire had spread in Canberra, Australia and decimated the area. After the bushfire was contained, locals were left with nothing but the task of cleaning up the devastation. While surveying the area, a puzzling discovery was revealed. Along with typical destruction associated with bushfires, there was extraordinary amount of damage that was not consistent with fire. Cars had been tossed and scattered about like toys and rooftops had sustained severe damage associated with high winds. Later, a local resident released video footage he had taken of what appeared to be a funnel within the out of control bushfire. It was later discovered a pyro-cumulonimbus cloud spawned a fire tornado that reached wind speeds of 111 to 135 miles per hours, measuring an EF-2 on the Enhanced-Fujita scale. Because of the unpredictability and sporadic nature of wildfires, fire tornados are a rare occurrence and are difficult for scientists to study. In fact, fire tornados were only recently discovered.
One can hope that amidst all the devastation and destruction plaguing California, it will allow scientists the opportunity to learn more about these destructive events and provide the public with new techniques regarding fire prevention and safety.
To learn more about this and other high-impact fire weather events, be sure to click here!
©2017 Weather Forecaster Ali Van Fleet
DISCUSSION: A large fire is currently burning in Ventura County in California. The Thomas Fire as it is named has currently burnt over 65,000 acres with no containment so far. The spread of the fire has even crossed U.S. Highway 101. The fire is currently burning at a rapid pace because of high winds with gusts around 40 to 50 mph (35 to 43 knots) as well as dew point temperatures as low as -5 degrees Fahrenheit at nearby locations such as Sandberg and Camarillo. These conditions are prevalent as a direct result of the Santa Ana wind phenomena which is occurring with a very strong ridge over the Pacific Coast, consequently bringing high winds even to the San Francisco Bay Area.
The fire is currently threatening to reach the populated portions of Ventura County including the City of Ventura. Evacuations have been ordered for several cities near the fire such as Santa Paula. In addition, the radar for the National Weather Service Los Angeles office was put into standby mode due to the fire being within a few miles of the radar. Furthermore, the radar site at Vandenburg Air Force has registered the smoke on the radar at about 30 dBZ (decibels with respect to height) which is about the same reflectivity as a rain shower.
The fire is likely to continue spreading at an alarming rate over the next few days due to a continuation of the high winds which is driving dry air to flow over the area. The National Weather Service has issued a Red Flag Warning for the entire Los Angeles and Ventura County areas due to the high winds and low humidity until Friday at the earliest. Evacuation orders have been issued for over 40,000 residents and more orders are expected within the coming days due to the spread of the fire. Southern California Edison reports blackouts affecting over 250,000 customers in Ventura and Santa Barbara Counties due to power lines going down because of the fire. Many schools in Ventura County have been and will remain closed due to the fires.
To learn more about fire weather stories and events, be sure to click here!
© 2017 Meteorologist JP Kalb
Dangerous Wildfires Burn Across Southern California (Credit: NWS Los Angeles/Oxnard, Los Angeles County Fire Department. Photo Credit: NASA Earth)
Discussion: Dangerous Wildfires have spread across parts of Southern California due to Santa Ana winds, low humidity and dry ground conditions. Strong Santa Ana winds across Los Angeles and Ventura counties have caused two large wildfires to break out. Currently the Thomas Fire, Creek Fire and Rye Fire are burning across these two counties. The Thomas Fire has burned 50,000 acres, the Creek fire has burned 11,000 acres and the Rye fire has burned 5,000 acres and is 5% contained. Due to these fires, mandatory and voluntary evacuations have been issued across Southern California. Strong winds are expected to continue in the region until Thursday, along with low humidity values ranging from 6 to 15%, which will keep the risk for fire breakouts high. This is the strongest and longest Santa Ana event of the year. Red Flag Warnings are in effect until Friday across Ventura and Los Angeles. It is important to take steps to protect yourself from the fires and the smoke and to follow the safety orders given by the authorities. It is also important in these weather conditions to exercise caution when using items that could ignite a fire i.e. cigarettes, campfires and brush clearing equipment, as any small fire could spread rapidly. In the photo above taken by NASA Earth, it shows the smoke plumes from the fires.
Santa Ana winds are most often characterized as being hot/dry winds which blow in from the desert towards the coast. These winds tend to occur during the following time frame (between September to May) when the desert is cooler than the Los Angeles basin. For more facts about Santa Ana winds click here! (http://people.atmos.ucla.edu/fovell/ASother/mm5/SantaAna/santa_ana_faq.html)
To learn more about fire weather and fire weather education, be sure to click here!
© 2017 Meteorologist Shannon Scully
DISCUSSION: As Northern California experienced wildfires that burnt at a devilish pace, the smoke from these fires impacted lives and events farther south. The smoke drifted heavily to the south because of a strong ridge of high pressure aloft which brought a northerly flow, which picked up the smoke and transported it southwards. A subsidence inversion at about 3000 to 5000 feet also influenced the situation by keeping the smoke trapped at lower pressure levels.
The smoke from the wildfires was very noticeable in the San Francisco Bay Area. The Bay Area Air Quality Management District (BAAQMD) had issued daily Spare the Air alerts during the event and forecasted the air quality to be unhealthy for the entire Bay Area until about October 18th. School districts have issued statements that students will not be outside for Physical Education classes as well as recess. In addition, the California Interscholastic Federation’s Central Coast Section, San Francisco Section, and Oakland Section made decisions to postpone many athletic contests due to the health concerns affiliated with the smoke. Football was heavily affected by the sections’ decisions as a full weekend of games have been postponed to the end of the season, which, then pushed the playoffs back a week. Visibility was also affected at most airports at various parts of the week including San Francisco International where there were delays around 90 minutes and longer. In addition, there have been reports that ash has fallen from the skies to land on cars and buildings across parts of the Bay Area especially in San Francisco, Oakland, and Berkeley.
The Bay Area was not the only area affected by the smoke. The smoke had also reached the Central Valley region including Fresno. The smoke had much less of an effect although visibilities dropped at times to 1 mile in certain locations as well as some athletic events getting cancelled. However, they had fewer days of heavy smoke due to an off-shore flow from the northeast which kept the smoke out.
To learn more about fire weather stories and events, be sure to click here!
© 2017 Meteorologist JP Kalb
DISCUSSION: It’s a seemingly normal scene for those in California to see the onslaught of wildfires in the dry seasons of the year. 2017 was not shy to such and is still proving is has more to show its residents in terms of widespread fire activity. Of late much of this activity is attributed to the high winds and low humidities driving fires into some of the most sensitive areas, recently the Sonoma, Napa and Mendocino counties.
Of concern are the fires across Northern California, nearly 22 in total that have currently burned 170,000 acres with minimal containment in sight. 17 people are confirmed deceased due to the spread of wildfires this week with 11 attributed to the Tubbs fire burning between Calistoga and Santa Rosa at 28,000 acres. CalFire estimates 3,500 structures have been destroyed by the fires and evacuations continue as winds are expected to shift this evening.
There will be no relief in sight as wildfires continue to spread in California. The Pacific Northwest is expected to see a weak frontal passage bringing some precipitation however no rainfall is expected for the fires in Northern California. This frontal passage will bring higher northerly winds especially in the higher elevations with decreased humidity. Winds as high as 40 knots can be seen in forecasts. Areas of Sonoma, Napa and Mendocino counties are currently under a red flag warning.
For more information on California’s fires visit the Global Weather and Climate Center!
© Meteorologist Jessica Olsen
Nearly 180 square miles of California’s wine country have been destroyed from wildfires. Over 2,000 structures have been destroyed causing massive evacuations in Napa, Sonoma and Mendocino counties. At least 15 people have died from the fires while another 150 people are still missing. Approximately 99,000 people are without power in the area. California’s Governor Jerry Brown has declared a state of emergency for Napa, Sonoma and Yuba counties. The fire started late Sunday night due to a series of lightning strikes rapidly growing from just 200 acres to over 68 square miles in less than 24 hours. Due to low surface dewpoints and strong winds, the fire was able to grow very quickly. Winds were measured at 60 mph in some areas of California. Unfortunately, dry conditions will persist at least through the next 5 days. Reports are noting that fires are 0% contained as of currently. Smoke from the fires is expanding into the surrounding areas that could cause difficulty breathing and low visibility. People traveling through or residing in the area should remain vigilant and heed the warnings. People should refrain from adding to the fires such as starting new fires.
The following is a statement from NASA describing the image above:
“NASA's Aqua satellite collected this natural-color image with the Moderate Resolution Imaging Spectroradiometer, MODIS, instrument on October 09, 2017. Actively burning areas (hot spots), detected by MODIS’s thermal bands, are outlined in red. Each hot spot is an area where the thermal detectors on the MODIS instrument recognized temperatures higher than background. When accompanied by plumes of smoke, as in this image, such hot spots are diagnostic for fire. NASA image courtesy Jeff Schmaltz LANCE/EOSDIS MODIS Rapid Response Team, GSFC.”
Come back for more updates on the Californian wildfires here!
ⓒ 2017 Meteorologist Brandie Cantrell
Discussion: Red Flag Warnings have been issued for much of Central Oregon, as very warm temperatures and a chance for scattered thunderstorms over the area is present. With the chance of scattered thunderstorms, the lightning strikes could cause new fire starts. Thunderstorm activity is expected over the Cascades and eastward tonight. Although the thunderstorms will diminish tomorrow and Friday, there will be an increase in the wind speed. These gusty winds combined with lowered humidity will be a wildfire risk. During a red flag warning, it is extremely important to heed local burn bans, properly discard any cigarettes, and avoid activities that cause open flames or sparks. With the dry vegetation, warm temperatures, gusty winds, and low humidity it doesn’t take much to spark a wildfire! To learn more about fire weather and fire weather education, be sure to click here!
©Meteorologist Shannon Scully
DISCUSSION: Well into the summer season, California is seeing its typical dry weather also bringing concern and fear as wildfires become a part of daily norms. Southern California of interest as recently nearly 3000 are evacuated due to the Whittier fire in Santa Barbara County.
Reports from Cal Fire have indicated that 8 homes and 12 outbuildings have burned, all due to a fire having initiated in the Santa Ynez Mountains. According to the County of Santa Barbara, as of 0700 PDT, 18,015 acres have burned since the initial fire on July 8th, 2017. This fire is said to be 36% contained. Onshore winds are expected to increase in the vicinity of this fire which may decrease temperatures however dry yet warm air is expected to remain in the region. In particular, temperatures in the Santa Ynez Mountains may see highs in the low 100’s with overall low relative humidities the Whittier fire a very dangerous situation for those in the immediate area.
According to Cal Fire, 95% of California’s wildfires are caused by people, these fires and others in California are still currently pending investigation. Contributions to the spread of the fire also are increased by current weather conditions which include; increased temperatures, decreased humidities, drier than normal to drought-like conditions, and wind, which can account for the additional oxygen, a fuel to push the fire through land.
In San Luis Obispo county, residents are still observing the prevalent Alamo fire that has decimated 28,687 acres with a containment of nearly 95%. Burning since July 6th, this fire has consumed 1 home and damaged another with minimal fire activity expected continue with this fire as crews monitor the situation.
Of additional interest is the Garza Fire, in Kings County, burned 48,403 acres with a 72% containment. This fire has burned 1 minor building with no structures currently threatened. There are currently over a dozen fires in the state of California, for more information on wildfires, stayed tuned to the Global Weather and Climate Center for more information!
© Meteorologist Jessica Olsen
California, State Of. "Cal Fire." Cal Fire. N.p., n.d. Web. 16 July 2017.
"Whittier Fire Information and Updates." Whittier Fire Information. N.p., n.d. Web. 16 July 2017.