Whether you think of spring as beginning at the onset of March or you’re a purist that waits until the Spring Equinox (on March 20th) before declaring the onset of the season, there’s no questioning that we’re enjoying spring-like weather this week. In fact, temps this week will be as much as 10° (if not more) above normals for mid-March -- running closer to the normals for late April or even early May as seen in these 4 p.m. readings around the area!
And certainly few if any of us will complain much about a spell of mainly dry weather, even if it means running the air-conditioning more than we might like to!
Don’t look for any significant weather systems to impact the lower Mississippi Valley before the early to middle part of next week. It looks like we are locked into a late spring weather pattern, with high pressure centered off the mid-Atlantic Coast and a “return flow” pattern that will keep the low level flow coming in from the southeast and south. This “Gulf Return” pattern means continued inflow of Gulf moisture.
Look for morning minimums in the 60°s each day, with fog returning for each morning drive. In fact, a Dense Fog Advisory has been posted for much of the area from late tonight into Thursday morning.
Afternoon highs will climb to 80° or more each day, with daytime heating and the moist Gulf air being just unstable enough to allow for spotty to possible isolated afternoon and evening t-showers -- like those that bubbled up near Donaldsonville and over sections of East Baton Rouge and East Feliciana parishes on Tuesday evening. But all in all, rain chances each day -- right through Sunday -- will be around 20% or less. Not enough for a region-wide wet day any time this week, but over the course of the next five days or so, you may get a shower or two in your backyard.
Why no frontal systems over the coming days? Right now the Polar jet stream -- U.S.’s main storm track during the winter and early spring -- has retreated to the north, keeping active weather systems over the northern tier of states and along the Canada/U.S. border. The way things look right now, that pattern should start breaking down as we head into the weekend, with the Polar jet developing a ‘dip’ (a trough in the upper-air flow) over the eastern Pacific and U.S. West Coast.
Truth is, it is still a little too early to be certain about how the upper-air flow changes in the next four to five days, but if this outlook does indeed develops, we should anticipate a possible frontal system moving into the lower Mississippi Valley along a Tuesday/Wednesday time frame.
So enjoy the warm days and get ready for what should be a decent St. Patty’s Parade day on Saturday!