A chilly Mardi Gras, but no rain in sight
Published 7:00 am Tuesday, February 9, 2016
Sunday afternoon may have fooled you into thinking that spring was arriving early. Today will convince you that it’s still winter.
This year Mardi Gras is turning out dry but cold. Temperatures will climb out of the 30s, but stay in the 40s most of the day throughout south Mississippi and southeast Louisiana. Temperatures will peak briefly in the low 50s this afternoon.
The fact that it will be breezy much of the day will add an extra bite to the chilly air. Fortunately, any clouds around at the start of the day are forecast to give way to sunny skies.
After a cold start Sunday morning, with most locations in the area dipping a few degrees below freezing, it warmed up nicely on Sunday afternoon with highs near 60. Overnight Sunday, temperatures fell back into the 40s, making it the warmest night since Wednesday of last week.
But, Monday a cold front passed by ushering a colder air mass into the region. Unlike most cold frontal passages in the Gulf South, there were no rain showers, and in fact few clouds ahead of the front. What was noticeable was a sharp increase in the winds from the northwest.
Usually, we have several days between cold fronts, but today another cold frontal passage is forecast, bringing a reinforcing surge of colder air down from Canada. Clouds to our northeast caused by the rush of cold air southward could come pretty close to our area, but are expected to stay far enough north to give Mardi Gras parade-goers on the Gulf Coast and New Orleans a sunny day.
Forecasters used the term “moisture-starved” to describe Monday and Tuesday’s cold fronts. Usually winds ahead of cold fronts in our area swing around to a southerly direction. This is true not only at the surface, but at altitudes up to a several miles high where a southerly or southwesterly component to the wind brings in moisture-rich air from the Gulf and even the Pacific.
However, ahead of Monday’s front, winds from a few thousand feet above ground upward several miles were already northwesterly, cutting off any flow of moisture from the south. In fact, on both Monday and Tuesday, the flow ahead of the cold fronts is not expected to have any southerly component anywhere in the lowest 10 miles of the atmosphere.
This flow pattern is courtesy of a strong upper level trough settling over the eastern half of the country. This general pattern will stay in place for the remainder of the week, keeping us dry and relatively cool through the weekend.
If this week’s temperatures are too chilly for your liking, just be thankful you’re not in the Northeast. Folks in Albany, New York can look forward to highs in the teens and lows below zero this weekend.
Medium-range models forecast a pattern shift next week that could bring much warmer temperatures not only to us, but to the eastern half of the USA. I suspect people in upstate New York will appreciate the change more than we will.
By Skip Rigney