April was much cooler than average
Published 7:00 am Tuesday, May 1, 2018
By Skip Rigney
April came to an end yesterday, and it was noteworthy for being one of the coolest Aprils in decades in south Mississippi.
Not all of the weather data for April have been analyzed yet, but data available from the Southeast Regional Climate Center in Chapel Hill, North Carolina show that several weather stations in our area recorded unusually cool temperatures.
While April’s statistics are not yet available for locations within Pearl River County, nearby stations show just how cool April was.
The Slidell Airport is only 15 miles southwest of Picayune and temperatures in the two locations are usually very similar.
As of last Friday the average daily low temperature for April 2018 at Slidell Airport was the coolest of all Aprils going back to the start of weather data there 25 years ago.
It was a similar story at the weather station in Saucier, Mississippi in northern Harrison County about 25 miles southeast of Poplarville and and a similar distance east of Ceasar. As of last Friday the average daily low temperature in Saucier for April 2018 was the coldest in 64 years of records.
The average daily maximum temperature was the second coolest out of the last 64 Aprils.
No ranking data are available for Poplarville yet. However, preliminary data provided by the Poplarville Experiment Station show that only eight mornings in April were warmer than the historical average low temperatures for those dates. The remaining 22 were cooler than the historical averages.This April’s unusual coolness was slightly more evident in daily minimum temperatures, which usually occur overnight and in the early morning hours, than in the daily maximum temperatures, which usually occur in the afternoon.
This is probably an indication of drier-than-normal humidities during much of the month.
The more water vapor there is in the air, the more the atmosphere acts like a blanket, trapping more of the heat absorbed by the ground and keeping that heat energy in the air near the surface. With drier air, more cooling takes place overnight.
That doesn’t mean that we lacked rain in April. Due mainly to a heavy rain on April 14th, most of the county saw between six and 10 inches of rain in April, significantly above the historical average for the month, which is about five inches.
While spring has been hanging on, keeping hints of summer heat and humidity at bay, over the next few days we get a glimpse of the transition to an early summer pattern.
A large surface high pressure system is setting up over the North Atlantic Ocean.
The Gulf of Mexico and its bordering states will be on the western edge of the high pressure ridge.
Southeasterly winds will bring warm air with temperatures ranging from the high 60s at night to the lower and middle 80s for daytime highs. You will probably notice a muggier feel to the air as humidities rise.
Rain chances increase on Friday and Saturday as a weak cool front approaches from the west. It’s too early to tell if showers will continue into Sunday. Even after the front makes it through our area, don’t expect much of a cool down.