Tropical weather system rainfall moves county to low level of index used to indicate drought conditions
Early in the afternoon of June 17, the Sarasota County Fire Department lifted the burn ban that it issued on May 5.
“The ban was lifted as the Keetch Bryan Drought Index (KBDI) fell below 500 for seven consecutive days, reducing the wildfire threat in Sarasota County,” a county news release pointed out.
A June 17 graphic showed Sarasota County among southern Florida counties in the index group with values from 0 to 99, following heavy rain last week associated with the tropical weather system Invest 90L.
County staff explained in early May that the Fire Department automatically implements a burn ban when the KDBI reaches 500, as noted in Section 58-2 of the Sarasota County Code.
The Florida Department of Agriculture and Consumer Services explains the following: “The Keetch-Byram drought index (KBDI) is a continuous reference scale for estimating the dryness of the soil and duff layers. The index increases for each day without rain (the amount of increase depends on the daily high temperature) and decreases when it rains. The scale ranges from 0 (no moisture deficit) to 800. The range of the index is determined by assuming that there is 8 inches of moisture in a saturated soil that is readily available to the vegetation.”
The department adds, “High values of the KBDI are an indication that conditions are favorable for the occurrence and spread of wildfires, but drought is not by itself a prerequisite for wildfires. Other weather factors, such as wind, temperature, relative humidity and atmospheric stability, play a major role in determining the actual fire danger.”
As The Sarasota News Leader reported last week, weather.com identified Siesta Key as the area of the county that received the largest amount of rain on June 11: 11.49 inches. Portions of the city of Sarasota and St. Armands Circle also were inundated by the downpours, as county Public Works Director Spencer Anderson explained in a county video.
On June 14, in its weekly aquifer update, the Southwest Florida Water Management District reported that, as of June 12, the rainfall total for the month in the South portion of its jurisdiction, which includes Sarasota County, was 6.77 inches. That compared to the historic average of 7.97 inches. For the year to date, through June 12, the District noted, the total for the South area was 16.03 inches, with the historic average from January through June put at 21.77 inches.
“Sarasota County Fire Department officials will continue to monitor conditions,” the county news release pointed out. “Residents are reminded to take precautions to protect themselves from fire danger and follow local open burning ordinance rules and regulations as outlined in Sarasota County Code Section 54-116,” the release adds.
For more information and tips to protect property from wildfires, individuals may call 311 in Sarasota County or visit scgov.net/fire.