Statewide Discussion: Overall dry conditions and the persistence of the heat dome through August has resulted in notable stress on both herbaceous and woody fuels and increasing fuels availability. Flash drought development resulting from above normal temperatures and the absence of moisture, most notably across the southern counties, has enhanced fire danger noted by increasing new wildfire occurrence. While initial attack efforts have been largely successful to date, recent fire behavior is exhibiting increased resistance to control efforts and large fire potential is expected to increase in the southern third of Oklahoma where mounting precipitation deficits, lack of soil moisture and enhanced fuels availability have become concerning. Energy Release Component values in this area have eclipsed the 90th percentile where resistance to control and heavier resource commitment is expected as an upper level ridge builds back in over the area later this week ushering in a return to above normal temperatures and expectation of dry conditions.
Today: Generally light winds through the day will limit rates of fire spread with temperatures in the 90°’s, afternoon relative humidity values 24-37% and fine-dead fuel moisture values 5-6% over most of Oklahoma and potential for 4% observation nearer to the Red River. The highest fire danger indices today will reside in southwestern and south-central Oklahoma where head fire rates if spread in grass-dominated fuels around 95 ft/min with flame lengths 6-9 ft. High-risk fuels (brush/juniper) will exhibit ROS 35-65 ft/min with flame lengths 6-16 ft and problematic fire behavior in oak/juniper fuels. Pine and Pine/Hardwood fuels in southeastern Oklahoma will continue to exhibit problematic fire behavior including single and group tree torching including shortduration crown runs in pine plantations. Fire behavior will moderate into the evening as temperatures cool into the 60°’s with fair overnight moisture recovery.
Thursday: Temperatures will again be in the 90°’s with potential for 100° in far southwestern Oklahoma coupled with afternoon relative humidity values ranging from 20% southwest to 42% northeast under clear skies yielding fine-dead fuel moisture values again 4-6%. Rather light and somewhat variable east component winds will limit rates spread in grass-dominated fuels to less than 90 ft/min south and less than 50 ft/min further north. Initial attack efforts are expected to be successful noting that problematic fire behavior across the southern counties should be anticipated in high-risk fuels.
Near-Term: The heat dome is expected to build back in later this week and into the Labor Day weekend with above normal temperatures and continued dry conditions. Elevated fire danger is expected across southern Oklahoma expanding into western Oklahoma with Energy Release Component values increasing raising concern as >90th percentile observations expand.
Burn Bans:
