Dry and pleasant Memorial Day weekend

Published 4:12 pm Saturday, May 28, 2022

By Skip Rigney

A dry Memorial Day weekend is in store after rains earlier in the week erased most of what was left of the precipitation deficit of the past seven months.

Most locations in the county accumulated three to five inches of rain over the course of the week according to estimates from the National Weather Service radar in Slidell and local weather observers. The exception was the northwest quadrant of the county where lesser totals fell into the 1.5 to 3.0 inch range.

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A slow-moving, back-and-forth frontal system at ground level and an equally lethargic low pressure at upper altitudes over the Great Plains were responsible for the several rounds of showers and thunderstorms from last Saturday through Thursday morning.

Fair skies replaced the clouds on Thursday afternoon as the centerline of the upper low pressure trough finally moved over us and we came under the influence of dry westerly flow aloft.

By Friday the center of the upper low was well to our northeast over Ohio. In its wake above the Mississippi River Valley from Minnesota to Mississippi upper winds were veering to the northwest pushing much drier, even slightly cool, air into the Gulf South.

This morning (Saturday) should be very pleasant with temperatures starting out near 60 degrees. It’s been three weeks since it was this cool in the morning, and it might be September or October before we have another morning with lows near 60.

Even as the bright May sunshine sends the mercury into the upper 80s on Saturday afternoon, low humidity will make it more comfortable than most days with similar afternoon temperatures later in the summer. Dew point temperatures, which are a good measure of how much moisture is in the air, are forecast to hang around 60 most of Saturday.

It’s when dew points rise to about 65 that even those of us who are acclimated to the muggy Deep South begin to notice the stickiness.

Today the centerline of a ridge of surface high pressure is right over us, but by Sunday it is forecast to have moved to our east. With clockwise circulation around high pressure systems, that means our surface winds will be veering back to a southeasterly direction. Higher humidity air from over the Gulf of Mexico will begin streaming back in.

So, Sunday and Memorial Day will be back to feeling more summer-like, but high pressure in the atmosphere above us will still be strong enough to squash any clouds before they grow tall enough to produce showers. A slight chance of showers may return by Tuesday and for the remainder of the upcoming work week, but nothing like the widespread rain that fell this past week. In fact, it’s very possible that some or all of Pearl River County will make it through Friday with no rain.

This coming Wednesday is June 1st, which climate statisticians consider the first day of summer. It also is the official start of the 2022 hurricane season. According to the Tropics Hazards Outlook from NOAA’s Climate Prediction Center, tropical development in the Atlantic, Caribbean, or Gulf of Mexico doesn’t appear likely during the first week of the season this year. That outlook is available online at www.cpc.ncep.noaa.gov.