A complex forecast will unfold as we head through this weekend and into and through next week. This forecast will likely change and have to be massaged through the next 72 hours before things really come into focus. Please keep tabs on the weather this week and through this weekend.
I’m going to break this down by round with a quick forecast, and follow it with a brief explanation, along with the variables and uncertainties.
Round 1:
Thursday and into Friday, there will be a chance for a few showers and maybe a rumble of thunder across the area. Highs will be in the mid to upper 60s.
This first round will be pretty benign. Notice that the GFS model image above shows very little precipitation. The models have jumped back and forth on things for Thursday and Friday. About every six hours they flip flop on which day will be wetter. If anything, all this is doing is giving the area a teaser for the weekend. There isn”t much uncertainty here on threats. Simply just how much rain will fall – very little or a little more are the choices. Severe weather isn’t anticipated and it should be just a mild rain.
This is the start of a snowball effect as we head through the next couple of days though. So on to Round 2…
Round 2:
Saturday there will be a chance for showers and storms with highs around 70. This may bring with it the opportunity for strong to severe storms. The threat looks pretty limited at this point, but is worth mentioning. Storms would pick up between about noon and 2pm and last through about 8pm.
A pretty stout system will be pushing through the area along the leading edge of some pretty cold air. The exact path of this storm system will be the key to figuring out what weather to expect.We will also need to keep tabs on how the front is aligned.
The placement of the surface and 850mb low versus where the 500mb low is centered will tell us how much shear to expect. The alignment – or orientation – of the front will tell us what “storm modes” will be most likely.
There is a fair amount of uncertainty with this system – and I know that can make people uncomfortable. The good news is, at this time, there is no data to suggest that this system will be capable of producing large devastating tornadoes. Nor is there any data that suggests it will be a giant blizzard.
What we are trying to determine is how potent the storms will be, either regular rain with some gusty wind or storms with wind more than 60mph. And we are also trying to determine just how cold the air will be back in behind it. That leads s to round 3…
Round 3:
The cold air comes crashing into South Mississippi Sunday morning and lingers through Tuesday. Temperatures on Sunday may get stuck in the 40s if the cloud cover decide to hang out with us. If we clear out, the temperatures will likely rebound to around 50. Monday and Tuesday temperatures will be below freezing in the morning and into the 40- to 50-degree range in the afternoon.
As the front exits, wind from the northwest will push in some pretty cold air. You’ll probably hear about the Chiefs-Patriots game all week being crazy cold with wind chills in the negative-20s… We will be getting that same air, just not as cold. And what we are trying to determine is how much modification will occur to that air as it pushes south. The big snows from this weekend will likely melt some this week, but if they remain, it means the colder air will be able to drive further south.
Add to that, the orientation of the front itself will dictate just how fast the cold air pile-drives the area, too.
Further complicating the process is the next storm system that arrives on Wednesday of next week. There is some data that shows the next system speeding up a bit. If that happens, the wind would shift back around to the south a bit quick on Monday leading to temperatures that wouldn’t be quite as cold.
Further complicating things…
Round 1 is going to dictate just how warm we get ahead of Round 2. The warmer we are for Round 2, the better the chance for severe storms. And Round 1 will make it warmer for Round 2 if Round 1 isn’t as rainy and the front that drapes across the area falls apart quicker.
The warmer we are for Round 2, the more likely it is that we held on to a south wind. A more south wind means the front is oriented north-south, and less east-west. The more north-south the front is oriented, the quicker the change from warm-to-cold will be. It also, again, means a bigger threat for a few severe storms.
The cooler we are in Round 2, the more likely the front is oriented more west-east. This would mean an oozing-in of colder air, less severe weather, and a good cold rain. Depending on how things shake out as the system passes, it means a better chance for lingering moisture behind the front, too.
Both of those outcomes would dictate how Round 3 occurs. Because if the cold air gets in here faster, it likely means we dry out quicker, clear the clouds and tank our temperatures into the 20s. The slower the cold air gets here, the more we hold on to clouds, stay colder Sunday, but stay warmer on Monday morning.
And once that cold air is here, the speed of the next system will dictate how long it sticks around. And the speed of “Round 4” will be dictated by Round 3, which is dictated by Round 2, and that is predicated on Round 1.
You can see why this gets so tricky.
What we will do during the next few days is use math and statistics to determine which step is most likely to happen at which time and to what degree.
This may sound pretty binary – like either one or the other happens – but sadly, it isn’t. Because the most likely scenario is a mixture of each, at each step. And it is why forecasting beyond 72 hours gets difficult. Why forecasting beyond 7 days is pretty tough to nail down specifics. And why beyond two weeks we use words like “wetter” or “cooler” instead of real numbers.
