NEAR-TERM: Weather will be quiet in the near-term with chilly nights and seasonal afternoons. Lows tonight will be falling into the 40s, while highs tomorrow will climb into the mid-60s. South winds increasing on Monday ahead of the strong Arctic front poised to come in on Tuesday.
MONDAY NIGHT/TUESDAY MORNING: The most interesting time continues to be Tuesday morning as the coldest air will be racing down the plains. Meanwhile, a narrow band of light-to-moderate precipitation will develop along the front. There is still no clear answer as to the type of precipitation across Acadiana as global models, European and GFS, have been going back and forth. This is to be expected as the shallow nature of the wedge of Arctic air may give the models fits.
For snow-lovers, the recent trend in the GFS model will make you happy. Yesterday, the GFS model was the warmer of the two, keeping the frozen precipitation well north of Acadiana. Today, however, the GFS has been trending colder and the European has been trending warmer. An analysis of yesterday afternoon’s GFS model shows surface temperatures in the 37-40 degree range with a solid tongue of warmer air a couple thousand feet above the ground. This scenario would mean an all-rain event for Acadiana, as the precipitation would not have time to refreeze before hitting the ground. In today’s run, however, surface temperatures are much colder, in the 34-36 degree range. Also, the warmer air aloft is not nearly as pronounced. In fact, the most recent GFS model shows freezing temperatures throughout the atmospheric column, with the only exception being right near the surface. If the most recent GFS verifies, chances may be a little higher to see some snowflakes before the precipitation is done mid-morning Tuesday.
The European model shows a likely all-rain event across most of Acadiana, with the exception being the northern parts of Acadiana (Evangeline, Allen, St. Landry). Even the warmer European model shows the freezing line getting south of Alexandria, as most of the models now do. This means, regardless of what happens in Acadiana, the chances for winter precipitation definitely seem to be increasing across the central parts of the state. Accumulations still look very unlikely though, except on elevated surfaces that may cool faster. Ground temperatures across central Louisiana and Acadiana will be well too warm for anything to stick or accumulate. Sometimes, if the winter precipitation is heavier, ground temperatures can cool quicker, but any winter precipitation that does fall should be fairly light in nature.
BOTTOM LINE: The forecast I made yesterday still seems like a reasonable estimation of what could happen.
A betting man would go with an all-rain event for most of Acadiana, at least south of I-10, but with the freezing line not far away and the GFS trending colder, there is definitely still hope! I still believe there will be a zone across Beauregard, Allen, Evangeline, and St. Landry where a wintry mix could be possible. This would include rain with some sleet pellets and/or snowflakes mixing in from time-to-time. Chances for a pure sleet/snow scenario will be higher across central parts of the state.