Meteorologists determine the onset and the end of a drought by carefully monitoring meteorological and hydrological variables such as precipitation patterns, soil moisture, and stream flow. To do this, meteorologists make use of various indices that show deficits in precipitation over periods of time.
So what is considered a drought? A drought is a period of unusually persistent dry weather that persists long enough to cause serious problems such as crop damage and/or water supply shortages. The severity of the drought depends upon the degree of moisture deficiency, the duration, and the size of the affected area.
There are four different ways droughts can be defined. Meteorological, agricultural, hydrological, and socioeconomic.
Meteorologically a drought is determined by the measure of departure of precipitation from normal. An agricultural drought refers to a situation where the amount of moisture in the soil no longer meets the needs of a particular crop. A hydrological drought occurs when surface and subsurface water supplies are below normal. A socioeconomic drought refers to the situation that occurs when physical water shortages begin to affect people.
Lack of rainfall for an extended period of time can affect farmers as well as metropolitan areas. Before long, we are told to stop washing our cars, cease watering the grass, and take other water conservation steps.
The drought index this week shows much of southwest Florida under a severe drought. The remaining area is nearly all in a moderate drought. Rainfall at Page Field in Fort Myers since January 1st is only 3.27 inches which is over 5 inches below average. At the Naples airport the total rainfall since January 1st has been 3.40 inches which is nearly 5 inches below average. In both cases these rainfall amounts are less than 42% of the average rainfall between January 1st and April 23rd.
Much of Lee and Hendry counties and all of Collier county is under severe drought conditions. In addition to the severe drought condition, fire danger is in the very high category in these counties.
The end of a drought can occur as gradually as it began. Soaking rains are best to alleviate drought. With rainy season just around the corner there is relief in the near future. Good news for now is there is rain in the forecast Friday through Sunday which will help our drought conditions and our very high fire danger.