Statewide Discussion: Early weekend rainfall was held to the southern Oklahoma with dry, cold-front associated air in northern Oklahoma – a disappointing outcome for northwestern and northern counties where separation from wetting rains continues to limit herbaceous green-up holding fire danger concerns in place. An active, unsettled forecast for the week ahead with rain/storm chances from Tuesday into the weekend. Dryline location will determine the wildfire risk (west of the dryline) and rain/storm chances (east). Fire weather will become a concern later this week in the Panhandle
and northwestern counties dependent upon realized rainfall and dryline placement.
Today: Southerly winds are expected to increase today becoming quite gusty this afternoon and persisting overnight. Good overnight moisture recovery and dew point temperatures above 40° will hold afternoon relative humidity values above critical threshold in all but the western Panhandle counties. While ignition potential will be limited today and initial attack success is expected to remain good, any established wildfire in the high-severity fuels (CRP, un-grazed rangelands, etc.) will present resistance to control with Energy Release Component holding around the 80th percentile.
Oklahoma Panhandle: Temperature 81°-84° under clear skies with relative humidity values 11% in Cimarron County to around 23% in Beaver County will result in fine-dead fuel moisture values ranging from 2%-4% from west to east. Southerly winds will gradually increase into the afternoon when sustained southwest winds 15-22 mph gusting around 30 mph are expected. During peak burning conditions today, rangeland fuels will support head fire rates of spread 130-183 ft/min with flame lengths 11-14 ft. Relative humidity values will improve after sunset although winds remain elevated with gusts through the overnight before shifting to the north by early morning.
Northwestern/Western/North-Central Oklahoma: With dewpoint temperatures above 40° and dry-bulb temperatures 71°-81°, afternoon relative humidity values will remain above critical threshold in the 28-38% range limiting ignition potential to some extent. Although localized 5% observations cannot be ruled out, fine-dead fuel moisture will tap 6% widely across the area. Southerly winds will increase through the day sustained 19-25 mph gusting above 30 mph at times. A wildfire that becomes established in the heavily loaded fuels will exhibit head fire rates of spread 120-175 ft/min with flame lengths 10-13 ft. on average. Good overnight moisture recovery will provide good initial attack opportunity although large fire development (>300 acres) is possible.
Near-Term: While the southern tier of counties received a boost of moisture in the last rain system, the flash drought development across the northern counties intensified from abnormally-dry to moderate drought from Woods County into far western Kay County. Herbaceous green-up has been retarded with the lack of recurrent rainfall and given increasing evaporative demand as plants break dormancy there has been a drought compounding effect. The
current 7-day Quantitative Precipitation Forecast does hold some hope, especially for the north-central counties, but given recent weather system performance no drought-fixing moisture shows in the near-term forecast. In the days ahead, a bimodal weather threat will develop across Oklahoma with severe potential east of the dryline and fire weather west. Placement of the dryline will be determinant of the fire danger severity that will be focused on the Panhandle and northwestern counties. Today is the highest fire danger day of the next three days.
The next update to the Oklahoma Wildfire Situation report will be issued Wednesday, April 24.
County Burn Bans: No County Burn Bans enacted at this time.
