Cooler air on the way, but no freezes
Published 7:00 am Saturday, November 14, 2020
By Skip Rigney
The weather the last couple of days has been beautiful. Blue skies, low humidities, and daytime temperatures mostly in the 70s can make autumn a wonderful season in south Mississippi. (It almost helps make up for the scarcity of fall foliage.) It looks like today will be more of the same, although you may notice that the humidity is a little higher than the last couple of days.
It’s hard to believe that one year ago we were having a record November cold spell. On November 13, 2019, temperatures stayed in the 40s all day. The next morning Poplarville set a daily record low of 22 degrees, and that was followed the next morning by a record for that date of 25 degrees. It was truly an unusually early and severe freeze. In fact, it was the coldest weather we had last fall and winter.
Mid-November is the time of year that we can normally expect our first freezing weather in Pearl River County. However, temperatures have fallen below 33 degrees as early as late October, and in several years out of the last one hundred or so of weather record keeping in the county, the first freeze didn’t happen until early January.
There is a cold front on the way. By this evening the front will be moving southeastward through Oklahoma and Missouri. Forecasters expect it to pass through our county Sunday afternoon or evening. A few isolated showers associated with the front will be our only chance of rain during the upcoming week. If any brief showers do occur Sunday, they aren’t expected to drop more than a few hundredths of an inch of rain.
High pressure will build in behind the front and dominate our weather pattern most of the week. Not only will the air mass behind the front be very dry, it will be seasonably cool. Monday through Thursday expect lows in the 40s and highs around 70 degrees. Gradual warming is forecast for Friday and into next weekend.
That means no threat of freezing weather for at least another week. And, long range forecasters at the National Weather Service’s Climate Prediction Center (CPC) in College Park, Maryland, expect mostly warmer-than-normal temperatures through the end of November.
Global weather patterns tend to favor a relatively mild and dry late fall and winter along the Gulf Coast when sea surface temperatures in the eastern and central tropical Pacific are cooler-than-normal. That’s the condition known as La Nina, the opposite of El Nino.
La Nina strengthened during October, and scientists at CPC predict that it will continue through the winter according to their weekly discussion released Thursday.
Of course, La Nina/El Nino is not the only broad-scale climate oscillation that influences what kind of winter we have. Meteorologists also monitor the pressure pattern in the polar region, which is known as the Arctic Oscillation.
And, then there’s this. The linked fluids of the ocean and atmosphere are what scientists call a deterministic chaotic system. That’s a fancy way of saying that there is simply no way of knowing with perfection all of the factors, large and small, that will determine our weather. A butterfly flapping its wings in India may be responsible for the next surge of frigid air coming from the Arctic to Mississippi.