Warm air to return after a cool Sunday

Published 7:00 am Saturday, December 11, 2021

By Skip Rigney

A front will move through the area Saturday followed by seasonably cool weather on Sunday. Forecast lows Sunday morning in the 40s and highs Sunday afternoon in the mid-60s will almost exactly match the historical average temperatures for this time of year.

That is quite a contrast from what we’ve experienced so far in December. Temperatures in Pearl River County have been 5 to 17 degrees warmer than average on eight of the first ten days of the month. Friday’s highs climbed into the 80s at some locations, threatening the records for the date. Poplarville’s previous record was 82 degrees set in 1931. The warm air combined with abnormally high humidity to make Friday feel unusually muggy for a December day.

Saturday will also start off muggy and much warmer than average until rain, thunderstorms, and cooler air arrive with the front. Showers will end Saturday night, but north winds will help temperatures continue to fall into the lower to middle 40s by Sunday morning.

But don’t expect the cool air to stay in south Mississippi very long. By Monday, in response to cold air plunging southward along the west coast of the United States, a ridge of high pressure several miles above ground will rapidly intensify over the eastern two-thirds of the country. The warm bubble of air associated with this unusually strong upper-altitude high pressure will result in ground level temperatures soaring to near-record levels later in the week from the Great Plains to the Gulf Coast.

Afternoon highs will climb back into the lower 70s in Pearl River County on Monday and into the middle to upper 70s the rest of the week. That’s warmer than over 90 percent of the highs observed at the Poplarville Experiment Station in mid-December over the past century. The warmest temperature in the historical record at Poplarville for December 15-18 is 82 degrees.

Afternoons here during most of the upcoming week will be about as warm as in Honolulu, Hawaii. In fact, with lower rain chances and lighter winds forecast for Pearl River County than Honolulu this week, maybe we should mount a tourism campaign targeted at travelers looking for a more affordable winter vacation.

If this kind of weather doesn’t pump up your Christmas spirit, consider the possible mid-week mood of folks in the upper Midwest. Thanks to the same massive high pressure system, the temperature in Des Moines, Iowa, is forecast to hit 70 on Wednesday. If that happens, it will be 35 degrees above the climatological normal, will obliterate the current record for December 15th of 59 degrees, and will even break their all-time high for December of 69 degrees.

Unlike the Saints’ playoff chances, hope is still alive for those of us in south Mississippi who prefer sweaters to shorts for Christmas Day gatherings. Some of the long-range computer models indicate a slight chance that cold air swirling around the polar regions may find an opening to plunge southward into the central and eastern United States in 10 to 15 days. But those model runs are still in the minority.

For now you might as well leave the song “Baby, It’s Cold Outside” off your holiday playlist.