Red Flag Warning 9:20 a.m. PT, December 9, 2012. NWS.
A Red Flag Warning is in effect for portions of the mountains and inland valleys of southern California Sunday night through Tuesday. The forecast calls for gusty northeast winds and low relative humidities. The strongest winds will be Sunday night and Monday with sustained winds of 15 to 30 with gusts up to 50 mph. The lowest humidities will occur Monday. The details vary across southern California — the specifics can be found at the National Weather Service.
The map was current as of 9:20 a.m. PT on Sunday. Red Flag Warnings can change throughout the day as the dozens of National Weather Service offices around the country update and revise their forecasts. For the most current data, visit this NWS site.
The Predictive Services section at the National Interagency Fire Center has issued their National Wildland Fire Potential Outlook for December, 2012 through March, 2013:
Significant Fire Potential
For December above normal significant wildland fire potential only exists across a portion of the west central U.S. stretching from Nebraska and Wyoming south through Colorado, Kansas and Oklahoma into Texas and New Mexico. Small portions of the Hawaiian Islands also show above normal significant wildland fire potential. By the January through March timeframe no above normal significant fire potential is expected in the U.S.
Below normal significant fire potential is expected across much of the southeastern U.S. for the entire forecast period.
Elsewhere expect near normal significant fire potential to exist. In many areas of the western U.S. this indicates fall and winter conditions that are generally considered out of fire season.
Climate and Drought Conditions
El Niño/Southern Oscillation (ENSO): Equatorial Pacific sea surface temperatures continue to indicate a neutral ENSO pattern.
Drought: Most of the nation had less than 50 percent of normal precipitation for November with only parts of the northwestern U.S. receiving normal to above normal rain and snow. Severe to exceptional drought continued over most of the central and western U.S. with pockets in the Southeast.
Fuel Conditions: Generally fuel conditions across the areas of most concern this time of year are better than normal. However, a trend of continued dryness across much of the central U.S. especially into Colorado and New Mexico indicate the possibility of seeing an early onset of fire season in these areas, though that should be later in the outlook period.
Weather Outlook: Current climate projections by the Climate Prediction Center favor a continuing neutral pattern. For December, long range models indicated a high probability of above normal temperatures over much of the southern U.S. and northern Alaska while below temperatures settle over the northern Plains, the upper Midwest and southwestern Alaska. Precipitation projections indicate a high likelihood of below median precipitation for the mid-Mississippi and Ohio Valleys. Southeastern Alaska will likely be drier than normal.
For January through March, projections show higher probabilities for above normal temperatures across northern Alaska, most of the Southwest, the Great Basin, the central and southern Rockies, the central and southern Plains, and the lower Mississippi Valley. Below normal temperatures are probable over the far northern Plains and southern Alaska. Precipitation will be above median over the Ohio and mid-Mississippi Valleys and below median across California and the Southwest.
On the second day of winter Red Flag Warnings for extreme wildfire danger are affecting portions of Colorado, Nebraska, Kansas, and and New Mexico.
One of the areas affects the Fern Lake Fire in Colorado where the warning will be in effect from noon Sunday until 6 a.m. Monday. The forecast the fire area for Sunday predicts southwest winds of 15 gusting to 24 mph, a high temperature of 51, sky cover of 49 percent, and a minimum relative humidity of 24 percent. However Sunday night will see the winds increasing to a maximum 41 with gusts to 62 along with a 22 percent chance of rain. The humidity will max out Sunday night at 75 percent.
The map was current as of 10:26 a.m. MT on Wednesday. Red Flag Warnings can change throughout the day as the dozens of National Weather Service offices around the country update and revise their forecasts. For the most current data, visit this NWS site.
The World Meteorological Orgnaization (WMO) has issued a “Provisional Statement on the State of Global Climate in 2012”. Some of their conclusions about the number of fires differ slightly from the stats we assembled on November 23, 2012.
The WMO’s document is lengthy, but below are some excerpts.
Global average temperature anomaly. Credit WMOLand and water temperature anomalies with respect ro 1961-1990 base period. Credit WMO
Wildfires
Dry conditions, combined with the heat in the Northern Hemisphere during most of spring and summer 2012, contributed to devastating wildfires. Across the contiguous United States, the number of wildfires throughout the year was the least since 2000; however, the amount of acres burned per fire event during the same period was the largest on record.
Significant wildfires also developed in the Eurasian Continent. In Spain, over 184,000 hectares of land had been scorched by wildfires between January 1st and September 15th, the highest in a decade. The most notable wildfire ignited on September 24th in Valencia, forcing nearly 2,000 people to evacuate. In August 2012, southern parts of Bosnia and Herzegovina recorded a wildfire that burned nearly 5,000 hectares of land, causing nearly 83 million U.S. dollars in damage.
Drought
2012 began with severe to exceptional drought, as defined by the North American Drought Monitor (NADM), across the south central and southeastern contiguous United States and the northern half of Mexico. In the southern Plains of the U.S., the 2012 drought was a continuation of severe drought conditions which developed in 2011. Throughout 2012, drought conditions evolved across the United States, improving in some areas while deteriorating in others. Continue reading “State of the global climate, 2012”
Fire Tornado path, Australia. Credit: research led by Rick McRae
We have previously written about events described as “fire tornadoes”, but research led by Rick McRae in Australia has us convinced that those should be more accurately called fire whirls, not tornadoes. We were never very comfortable using the term “fire tornado” for those events, but it has become common and we were not aware, until now, that a phenomenon many times more powerful existed.
Fire tornado documentation, Australia. Credit: research led by Rick McRae
Mr. McRae documented what was unquestionably a real fire tornado that occurred near Chapman, ACT, Australia during the McIntyres Hut Fire January 18, 2003.
Researchers had speculated about the ability of a fire to produce a tornado, but this is the first documentation of the creation of a true tornado by the convection column of a large fire.
In a video interview (scroll down and view the second video) and in a paper published October, 2012 in the journal Natural Hazards, he described a fire tornado as occurring over a vegetation fire, a process now known as the phenomenon of “pyro-tornadogenesis”. Under certain conditions, a fire can cause a pyro-cumulus cloud to form, which is not in itself unusual over a large fire. If the cloud continues to build, it can generate lightning, rain, and hail, much like a conventional large thunderstorm. And large thunderstorms can sometimes propagate a tornado, which is what happened over the McIntyrres Hut Fire.
Mr. McRae’s research determined that the fire tornado was moving across the ground at 30 kph (19 mph), had horizontal winds of 250 kph (149 mph), and vertical winds of 150 kph (93 mph).
Aftermath of a fire tornado, showing 12-15 meter tall trees broken off 2-3 meters above the ground. From research led by Rick McRae.
Dr. Jason Sharples, also associated with the research, described the differences between a fire tornado and a fire whirl:
Tornadoes are associated with thunderstorms and as such they are anchored to a thundercloud above, and are able to sporadically lift off the ground. Fire whirls, on the other hand, are anchored to the ground and do not require the presence of a thunderstorm.
Red Flag Warnings, 9:28 a.m. MT, November 21, 2012
The wildfire season is not over in some parts of the United States, as Red Flag Warnings have been posted for three areas:
Portions of southeast Wyoming and western Nebraska for late Wednesday morning and Wednesday afternoon; winds west 15 to 30 with gusts up to 45 mph across western Laramie County and up to 35 mph elsewhere; relative humidity as low as 10 percent
The southeast corner of Colorado, from 11 a.m. through 5 p.m. on Wednesday; winds southwest 15 to 25 mph with gusts up to 35 mph; relative humidity 7 to 12 percent.
The Florida Big Bend area, Red Flag Warning Wednesday afternoon for north to northwest winds 6 to 10 mph with gusts up to 15 mph; relative humidity 30 to 35 percent and lower on Thursday; Fire Weather Watch on Thursday for similar conditions.
There is no Red Flag Warning for central and western South Dakota, but the fire danger is elevated, with temperatures expected to be in the mid 60s and possibly low 70s on Wednesday. Relative humidity will be 15 to 20 percent with areas south of Interstate 90 likely seeing winds of 15 to 22 mph with gusts in the 25-30 mph range. Thursday will see 28 mph winds gusting at 35 to 40 with temperatures in the low 50s and relative humidity of 30 to 38 percent.
The map was current as of 9:28 a.m. MT on Wednesday. Red Flag Warnings can change throughout the day as the dozens of National Weather Service offices around the country update and revise their forecasts. For the most current data, visit this NWS site.
