Hot and dry gives way to warm and showery
Published 7:00 am Tuesday, May 22, 2018
By Skip Rigney
About ten days ago the weather map transitioned from a spring to summer pattern along the northern Gulf Coast. Hot and dry has been the rule as high pressure in the atmosphere above us caused the air to slowly sink and warm over our region.
Changes are underway for the upcoming week with a different type of summer pattern setting up. The high pressure above us has already weakened, and computer weather models are indicating that low pressure may form over the Gulf, which could become a major rainmaker.
Before looking ahead, it’s worth revisiting the recent heat. Depending on your exact location in Pearl River County, your first 90 degree day since last fall occurred between May 8th and May 14th as high temperatures were in the upper 80s to near 90 each afternoon.
Then the heat ramped up to another level. Last Tuesday was the hottest day ever recorded in the month of May at New Orleans International Airport where the mercury topped out at 97 degrees. Poplarville hit 95 degrees. One day earlier the Gulfport-Biloxi airport broke its record for May 14th with a high of 98 degrees.
The heat continued as record high temperatures across the South were approached, tied, or broken on Wednesday and Thursday.
Fortunately, temperatures this week will be closer to normal. The National Weather Service is forecasting highs in the upper 80s and lows near 70, which will still be a few degrees above the averages for this time of year.
With plenty of heat, more humidity, and less high pressure aloft to suppress clouds than we had last week, expect a 50/50 chance of the scattered afternoon thunderstorms typical of summer during the next couple of days.
By Friday the number of showers will depend on the development of a low pressure system in the Gulf of Mexico. As I write this on Monday morning, different computer models are producing different predictions and impacts for south Mississippi.
There is a possibility that low pressure in the Gulf could become organized enough to produce rains of several inches somewhere on the northern Gulf Coast starting Friday and into the Memorial Day weekend.
There is a slight chance that the system could organize into a preseason tropical depression or tropical storm. Keep up with the latest forecasts from the National Weather Service in Slidell at www.weather.gov/LIX/ on the Internet. There, you can type in your zip code or click on a map to get the latest detailed forecast. The website also has the latest weather headlines, watches, and warnings for south Mississippi and southeast Louisiana.
Another excellent website to bookmark as we head into tropical weather season is the National Hurricane Center at https://www.nhc.noaa.gov/. One of the many products available there is a five-day tropical weather outlook for the Atlantic Ocean and Gulf of Mexico.
As of Monday morning NHC gave a 20 percent chance that a tropical depression will form in the Gulf later this week. Keep an eye on whether that percentage increases or decreases as we head toward Friday.