By Skip Rigney

After last weekend’s deluge, high pressure kept us dry and sunny throughout the work week that just ended. Showers appear likely on Sunday with a few lingering into Monday before an even stronger ridge of high pressure brings back dry and very warm weather.

The extremely heavy rains that fell on the northern part of Pearl River County on May 9-11, especially Friday night May 10, were another example of the flooding spring rains that can hit our county.

A total of 12.75 inches of rain were recorded by the Poplarville Experiment Station for the period from Thursday morning May 9 through Sunday morning May 12. The area of heaviest rainfall extended eastward into Stone County with Perkinston measuring 14.07 inches.

The rains in the southern part of Pearl River County were much less but still significant. Radar and rain gauges indicated four to six inch totals for May 9-11 in locations such as Picayune, Carriere, and Ceasar.

The prodigious amounts of rain last weekend were the result of several factors. The atmosphere was very moist from the surface upward several miles.

A weak stationary boundary oriented east-west across south Mississippi served as a trigger for thunderstorm development. Finally, the orientation of the boundary with respect to the winds at higher levels in the atmosphere was such that new storms kept developing and moving over the same areas. This is often referred to as “training,” evoking the image of train rail cars moving over the same areas again and again.

Thankfully, the showers tomorrow, Sunday, May 19 won’t be nearly as heavy as last weekend’s drenchers.

A low pressure system will be passing well to our north through Missouri. A weak trough of low pressure will drop from the low’s center into north Mississippi, which will be close enough to kickoff Sunday’s showers.

A few stray showers may linger into Monday. Less than one inch of rain is expected over the two days for locales in south Mississippi according to the National Weather Service’s Weather Prediction Center.

Heading into Tuesday atmospheric pressures will be rising across the southeastern United States.

High pressure several miles aloft in the atmosphere will cause the air above us to be slowly sinking. That means dry, plenty of sunshine, and much warmer daytime temperatures for Tuesday through next Saturday.

Afternoon high temperatures will approach 90 degrees from Tuesday onward. On some afternoons, especially late in the week, forecasters predict that we could see our first lower 90s of the season.

Southerly winds will ensure that humidity will be increasing along with the temperatures, giving us our first real taste of summer.

It is often the case that when a ridge of high pressure pumps up temperatures over the southeastern U.S., a corresponding cold trough of low pressure settles in over the northwestern United States.

So, it’s not surprising that visitors this week to Old Faithful Geyser in Yellowstone National Park in Wyoming will be treated to freezing mornings, afternoons in the 40s, and a mix of rain and snow each day.

Late May in south Mississippi sounds pretty good.