Warm, dry weather to continue
By Skip Rigney
During the month of September, a drought has taken hold in many areas of the southeastern United States according to the U.S. Drought Monitor.
The Drought Monitor is a weekly map of drought conditions, which can be found online at droughtmonitor.unl.edu. It is produced jointly by the National Oceanic and Atmospheric Administration, the U.S. Department of Agriculture, and the National Drought Mitigation Center at the University of Nebraska-Lincoln.
At the beginning of September there were only a few isolated areas in Alabama, Georgia, and the Carolinas experiencing what the Monitor characterized as moderate drought. However, very little rainfall, in many cases none, has fallen over much of the Southeast this month.
Now, over half of Virginia, Kentucky, Tennessee, and Georgia are experiencing moderate drought. According to the Monitor, a moderate drought can be expected to occur every five to 10 years.
In Mississippi, over 70 percent of the state is now characterized as abnormally dry by the Monitor. That’s after we began the month with the entire state at or near normal rainfall and soil moisture conditions. Abnormally dry conditions can be expected to occur every three to five years at the location and time of year being considered.
Locally, most of the northern half of Pearl River County has received less than one-half inch of rain this month.
The Poplarville Experiment Station has had no measurable rain since Aug. 27, and it’s unlikely that there will be any rain through the end of the month. In 100 years of record-keeping at the station, only one other September has had zero rainfall. That was in 2009.
Most locations in the southern half of the county have picked up somewhere between 0.5 and 1.5 inches of rain this month, which is on the lower end of the one to six inch range that has been observed in about two-thirds of Septembers in the county. The average rainfall for the month over the last 30 years has been between 3.9 and 4.6 inches depending on your location in the county.
Often abnormally dry conditions are accompanied by warmer-than-normal temperatures, and that has been the case this month. Temperatures have been warmer than the long-term averages every day so far this September. On 15 of those days at the Poplarville Experiment Station, the maximum temperature has been five to 11 degrees above normal.
This hot, dry September has been associated with a persistent area of unusually strong high pressure several miles above the southeastern U.S. During most Septembers, tropical disturbances from south and east of us, and cool fronts from the north and west are our sources of rain and cooler temperatures. But this month, the dome of high pressure has blocked both types of systems from making it into the Gulf South.
This weekend and during the upcoming week, the upper high pressure system is forecast to strengthen even further.
That means only the slimmest chances of a shower along with high temperatures each day in the 90s. National Weather Service forecasters in Slidell indicate there’s a chance that record high temperatures will be set.
Looks like we’ll need to keep our air conditioners in high gear through at least the first week of October.