Intense, devastating fires flared up one week ago in Oklahoma, Kansas, and Texas. This article is part one of a three part series. It covers the long-term conditions leading into this horrendous fire day. Part One covers weather factors in February that contributed to extremely dry conditions in Beaver, Harper, and Woodward Counties.
(Photo: Carmen Fire Department 3/7/17)
The Starbuck Fire was sparked in Oklahoma and soon crossed into Kansas, where flames raced across the largest number of acres. Additional fires occurred in all three states. The speed and intensity of these fires tragically caused 6 fatalities, thousands of livestock, wildlife losses, hundreds of miles of lost fencing, the destruction of at least twenty homes, and an undetermined number of structures.
(Photo: Texas Nature Conservancy, Chris Hise 3/7/17)
The number of March fires in Oklahoma was actually greater on other days. On those days fires flared up, but conditions were not as extreme as on March 6, 2017. Fire fighters were able to gain control over these fires before they turned into fire giants.
The extreme conditions that came together in Beaver, Harper, and Woodward Counties on March 6th included a lack of February rainfall, low relative humidities and high winds. The four main fires in these counties, Starbuck, Beaver, 283, and Selman were grouped and designated as the Northwest Oklahoma Complex Fires. The weather conditions were a combination of longer and shorter conditions.
Rainfall during February 2017 provided good amounts of moisture in the south central part of the state. Unfortunately, it left the northeast and Panhandle far short of average moisture. The Oklahoma Mesonet Beaver had 0.10 of an inch over 30 days ending on March 1st. Buffalo received 0.13 of an inch during that 30 days.
On a departure from average map for February 2017 the dryer areas are orange with negative values. Places with above average rainfall are green. Darker shades show highest negative or positive departures.
This lack of rainfall in February popped up in the Keetch-Byram Drought Index as values over 400. This index estimated that areas from Woodward to Texas County were the driest in the state.
February in 2017 was an extremely warm month in Oklahoma. The average air temperature ranged from 7 to 11 degrees above Mesonet’s long-term 15-year average (2002-2016).
The nighttime temperatures in the Northwest Complex Fires area were only 5 degrees above average in minimum temperature.
The daytime temperatures were the heat drivers coming in 13 degrees above average from Woodward to Goodwell. Mays Ranch, on the Kansas border, was 14 degrees above its February maximum air temperature average.
Those above average temperatures contributed to the below average humidities of 11 to 12 percent for February in the fire areas from Woodward to Beaver.
Low rainfall, warm temperatures, and below average relative humidities dried dead fuels. The 1000-Hour Dead Fuel Moisture on March 6, 2017 was 5-6 percent between Woodward and Beaver. 1000 hour dead fuels are larger, downed, wooden branches 3-8 inches in diameter.
Part 2 explores the role low relative humidities in March played in the Northwest Oklahoma Complex Fires. Part 3 looks at Monday, March 6, 2017 wind speeds.
Thanks to all of the fire fighters. Their hard work and tireless efforts brought control to monster fires, saving lives and property. Thanks too for all of the generous donations in so many forms to help folks through one of the toughest set of fires in Oklahoma, Kansas, and Texas history.