Warm spring temperatures to continue
Published 7:00 am Tuesday, April 7, 2015
We can expect a fairly typical spring weather pattern for the next week. Surface high pressure centered in the western Atlantic Ocean will ridge into the Gulf of Mexico. Because of the rotation of the Earth, circulation around high-pressure cells in the Northern Hemisphere is clockwise. So, being to the west of a high centered in the Atlantic, our winds will have a southerly component transporting warm, humid air into our region.
Highs will be in the 80s and lows in the 60s. For the next couple of days, sinking air associated with the high should keep our shower chances slim to none despite the warm, moist air.
A frontal boundary and associated low pressure will be to our west over the central Great Plains extending to our north over the upper Midwest. By Thursday and Friday the front will be headed our way as a cool front. By Friday, the surface front and its associated upper level disturbance will significantly increase our chances of showers and thunderstorms.
Speaking of thunderstorms, the spring months of February through May are the most likely time of year for severe thunderstorms in Mississippi. The National Weather Service considers a thunderstorm severe if it produces a tornado, has winds of at least 58 mph (50 knots), and/or has hail at least one inch in diameter.
At this time, it looks like the main threat of severe weather on Thursday and Friday will remain far to the north and west of Mississippi. There is a slight chance on Friday that the atmosphere will be unstable enough with some quite cold air aloft for a few of the thunderstorms in our area to produce some small hail.
As happens more and more often as spring progresses here in south Mississippi, the cold front is likely to stall out and dissipate near us, or reverse course and head back north as a warm front. In either case, we are likely to have a chance of showers over the weekend. Those chances are likely to increase on Monday and Tuesday of next week as another surface cool front and associated strong trough of low pressure at upper levels heads our way out of the Great Plains.
Throughout this week and weekend, and into early next week, warm temperatures will be the rule with highs in the 80s and lows in the 60s.
Looking back over this past Easter weekend, the beautiful mild to cool middle of Saturday and Sunday was bracketed by rain Saturday morning and late Sunday afternoon and evening. The rain late Sunday was not associated with a surface front, but instead was caused by a disturbance several miles high in the atmosphere passing by from west to east. There was quite a bit of variation in rainfall amounts across the county. The heaviest rain was concentrated in a narrow strip in the southernmost quarter of the county stretching from the Pearl River through Picayune and the Salem and Caesar communities. Totals in that band were between one and one and a half inches, while much of the rest of the county received only one-third and two-thirds of an inch Sunday evening.
By Skip Rigney