Wildfires - September 2011


Updated: 6 October 2011


Overview

During September 2011, approximately 765,500 acres (309,500 hectares) burned across the country, slightly higher than the 10-year average of 614,300 acres (348,500 hectares) but less than the September record of 1.47 million acres (595,000 hectares), which burned in 2006. During the January-September period, 7.72 million acres (3.12 million hectares) burned across the U.S. — the 5th most in the 12-year period of record. The most acres burned during the January-September period occurred in 2006 when 9.1 million acres (3.68 million hectares) burned nationwide.

September Wildfire Statistics*

September 2011 2001-2010 Average (10-years) Rank (of 12 years) Record (year)
Area Burned 765,417 acres 614,273 acres 4thlargest (9thsmallest) 1,474,795 acres (2006)
Number of Fires 6,552 6,623 5thmost (7thleast) 13,598 (2010)
Area Burned
per Fire
116.8 acres 99.7 acres 3rdlargest (10thsmallest) 307.0 acres (2006)

Year-to-Date Wildfire Statistics*

Year-to-Date
as of September 30th 2011
2001-2010 Average (10-years) Rank (of 12 years) Record (year)
Area Burned 7,721,459 acres 5,948,948 acres 5th largest (8thsmallest) 9,074,358 acres (2006)
Number of Fires 60,422 64,563 4thleast (9thmost) 83,752 (2006)
Area Burned
per Fire
127.8 acres 91.7 acres 2nd largest (11thsmallest) 153.5 acres(2005)

*Data Source: The National Interagency Fire Center (NIFC) Situation Report.


Significant Events

Texas Wildfires 6 September 2011
Texas Wildfires 6 September 2011
Source: NASA

During the first week of September, three large wildfires raged across eastern Texas. As Tropical Storm Lee made landfall along the Louisiana coast, the storm caused strong winds to whip up across the state. The strong winds, combined with the ongoing drought, created ideal wildfire conditions. The Bastrop fire was ignited on September 4th, just east of Austin, Texas. The fire burned rapidly out of control with extremely low 10-hour and 100-hour fuel moistures reported. By the end of the month, the fire had burned over 34,000 acres (13,800 hectares) and destroyed over 1,600 homes. According to media reports, the fire broke the record for the number of homes lost due to a single fire in Texas history. The Riley Road fire burned northwest of Houston, and charred nearly 19,000 acres (7,700 hectares) before being fully contained on the 14th. The fire destroyed 76 structures in its path. The Bear Creek fire burned near Linden, Texas and covered over 40,000 acres (16,200 hectares) before containment on the 18th. For 2011 through the end of September, over 3.7 million acres (1.5 million hectares) have burned across the state of Texas.

Minnesota Wildfires 12 September 2011
Minnesota Pagami Creek Wildfire
12 September 2011
Source: NASA

The Pagami Creek fire burned approximately 93,000 acres (37,600 hectares) in the Superior National Forest in northern Minnesota by the end of September and was only 60 percent contained on the 30th. The fire was ignited on August 18th by a lightning strike. The fire was not initially suppressed to allow natural processes to take place in the forest. The fire had only grown to 13 acres (5 hectares) by September 12th. But after the 12th, strong winds and dry conditions caused the fire to grow rapidly out of control. The acreage burned is the tenth most by a single fire in Minnesota history, and the largest fire to affect the state since the Cloquet-Moose Lake Fire in 1918. By the end of September over 5.7 million dollars had been spent to control the wildfire.


Discussion

During September, dry conditions persisted for most of the country, with the exception of the track of Tropical Storm Lee and the Northeast. Above-normal temperatures dominated the western third of the country, in contrast to the summer period which was cooler than normal for the region. Above-normal temperatures were also present along the U.S.-Canadian Border, the Northeast, and Texas. Below-normal temperatures were present along the Gulf Coast, stretching into the Central Plains. See the U.S. Temperature and Precipitation discussion for more information. According to the U.S. Drought Monitor, the overall size of the drought footprint shrank slightly across the contiguous U.S. during September. Tropical Storm Lee, which made landfall along the Louisiana coast, moved northeastward and interacted with a frontal system, bringing heavy rainfall from the Gulf Coast, to Northeast, eliminating drought conditions for parts of the Lower Mississippi, Ohio, and Tennessee Valleys. Extreme drought (D3) persisted across Georgia, which did not receive any rainfall from Tropical Storm Lee. Exceptional drought (D4) continued across most of the Southern Plains, stretching into the Southwest. Severe drought (D2) conditions continued across parts of Iowa and Illinois, as well as extreme northern Minnesota. Abnormally dry conditions developed across the Northern Rockies and the central Great Basin.

Wildfire information and environmental conditions are provided by the National Interagency Fire Center (NIFC) and the U.S. Forest Service (USFS) Wildland Fire Assessment System (WFAS).

On September 1st, there were 58 large wildfires burning nationwide. The majority of the large wildfires were active across the northwestern quadrant of the country, with nine fires burning in Oregon, three in Washington, five in Idaho, four in Montana, and three in Wyoming. Dry conditions the second half of August increased the fire danger across the region, as well as the Keetch–Byram Drought Index (KBDI) values across the higher elevations. Extremely low 10-hour fuel moistures were widespread, with moderately low 100-hour and 1,000-hour fuel moistures. Twelve large wildfires were burning across the Southwest in California (4), Arizona (4), Nevada (2), New Mexico (1), and Colorado (1). During the second half of August, the monsoonal rain showers across the Southwest slowed significantly, and the heat across the region created ideal wildfire conditions. Very high fire danger was observed across portions of the Southwest, stretching across the Great Basin. Small fuels (10-hour fuel moistures) were extremely dry, while larger fuels (100-hour and 1,000-hour fuel moistures) were moderately dry across the region. KBDI values were relatively low. Across the Southern Plains, there were 15 large wildfires burning in Texas, as well as two in Arkansas and one in Oklahoma. Continued dryness and warm temperatures caused 10-hour fuel moistures to plummet and the fire danger to increase. KBDI were very high across the area. Single large wildfires were also active in Alabama, Minnesota, and in North Carolina.

By mid-September, there were 44 large wildfires burning across the country. There were 16 fires active across Washington (2), Oregon (8), Idaho (4), and Montana (2). Across the region, temperatures were above average and precipitation was below average during the first half of the month, which lowered fuel moistures of all sizes (10-hour, 100-hour, and 1,000-hour fuel moistures) and increased the fire danger and KBDI values. Five large fires were active across central California, where 10-hour and 100-hour fuel moistures were extremely low. Below-average precipitation during the first two weeks of the month increased KBDI values. Across the South, 22 large wildfires were active in Texas (14), Louisiana (2), Oklahoma (5), and Arkansas (1). Dry and windy conditions were widespread the first half of September across the region causing high fire danger and KBDI values and extremely low 10-hour and 100-hour fuel moistures. One additional fire was active across northern Minnesota, where low 10-hour fuel moistures were observed.

By the end of September, large fire activity across the U.S. had slowed significantly, with 11 large fires actively burning. There were five large wildfires active across Idaho (3), Montana (1), and Oregon (1) in the Pacific Northwest. At the end of the month, the low elevations of the region were experiencing high fire danger. Extremely low 10-hour fuel moistures were also widespread, with the exception of the coastal regions, and 100-hour and 1,000-hour fuel moistures were moderately dry across the region. In Texas, four large wildfires remained active on September 30th. Continued dryness caused the fire danger to be extremely high across the eastern and northern portions of the state. Extremely low 10-hour fuel moistures and moderately dry 100-hour and 1,000-hour fuel moistures were associated with the ideal wildfire conditions. Extremely high KBDI values across the state were attributable to the ongoing exceptional drought. There was also a single large wildfire burning in north central Florida, where high KBDI values were observed. The Pagami Creek wildfire in Minnesota continued to burn in the Superior National Forest.


All Fire Related Maps


Citing This Report

NOAA National Climatic Data Center, State of the Climate: Wildfires for September 2011, published online October 2011, retrieved on July 24, 2014 from http://www.ncdc.noaa.gov/sotc/fire/2011/9.