High pressure to bring dry, warm weather
Published 7:00 am Saturday, May 22, 2021
By Skip Rigney
A dramatic weather pattern change is underway as high pressure strengthens over the eastern United States, bringing an end to rain in our area. Abundant bright May sunshine will also give us a taste of summer warmth during the coming week.
Showers this past Monday through Thursday continued a trend we have seen many times this spring, which is that the heaviest rainfall was concentrated in the southern end of Pearl River County. Totals those four days around Picayune and Nicholson were near three inches. Elsewhere one to three inches were common. The least rainfall in the county fell northeast of Poplarville where totals for the week were generally less than one inch.
We were on the southeastern edge of a very wet storm system that dropped much heavier amounts across south Louisiana and much of Texas and Arkansas. Rainfall totals of 10 to 20 inches were common near Baton Rouge, Lafayette, Lake Charles, and along many parts of the Texas coast.
However, over the past couple of days a sprawling, warm high pressure system stretching from eastern Canada down to Florida has been strengthening and expanding westward. The increasing pressure difference between the high to our east and lower pressures over the western Gulf made for windy conditions Thursday and Friday. Those winds are returning to more normal speeds as the centerline of the high moves closer to us.
Puffy daytime clouds will still form in our region during the next week, but the sinking air in the high pressure system will put a lid on how tall those clouds can grow.
Therefore, forecasters expect partly cloudy skies, but very slim rain chances from now through the coming week. If we avoid any isolated showers that do manage to form, it will be the longest stretch with no rain since March 3rd through 12th.
Not only will higher atmospheric pressure and subsiding air squash our rain chances, they will cause temperatures to rise to summertime levels. There have been only a handful of warm days this spring when highs reached the upper 80s. Those occurred in late April and the first week in May. A few locations in our region briefly hit 90 degrees on those days. Expect similarly warm afternoons this work week.
It will be noticeably less muggy over the next few days with dew point temperatures in the lower 60s, which is at least five degrees less than this past week. However, by Monday winds will become less easterly and take on a more southerly component. This will bring back more Gulf humidity, and by mid-week dew point temperatures are forecast to return to the muggy upper 60s.
Many of us will enjoy a dry stretch after a rainy May and a wet spring. Another reason to appreciate the upcoming days is that it will be our last full week before hurricane season begins on June 1st. According to NOAA’s seasonal outlook released on Thursday, which was in line with predictions published by other forecasting organizations earlier in the spring, we can expect 2021 to once again be a busier-than-average year in the tropics.
Fortunately, the first tropical disturbance in the Gulf of the year, which developed on Friday, will move into Texas too quickly to allow much intensification.