Bad news, snow lovers. This event isn’t likely for you.
So far the data coming in continues to suggest the changeover from rain to snow will occur near I-20. That means most of southern Mississippi will be wet – not snowy. The worst part is that temperatures will be in the mid 30s when the rain starts and only warm into the upper 30s and low 40s during the day while the rain is falling.
To the Data!
Right now the warm nose is the snow’s biggest enemy.
The Skew-T data shows that there is moisture in the Dendritic Growth Zone, there is Omega beneath the DGZ, there is lift, and there are cold enough temperatures at the surface.
But between about 1,500ft and about 8,000ft there is a big plume of warmer-than-freezing air.
The ‘warm nose’ is most pronounced in the NAM model (shown above) but it is also shown in the GFS and ECMWF model data. In fact, all available model data shows a warm nose that will be melting all the snowflakes.
Interestingly, the NAM model shown above has two things the GFS and the ECMWF lack – mid-level instability (though, not much) and lower-level temperatures near or below freezing closer to the ground.That may set the stage for my favorite weather term to develop: Thundersleet. That is where sleet is falling from a thunderstorm.
As an aside….
We have had thundersleet in the Pine Belt a few times during the last five years. In fact, when I went back to look, the Pine Belt had thundersleet back in 2019.
You guys!! We did it!! Thundersleet! I've now experienced all forms of thundering weather – rain, snow and sleet.
— Nick Lilja (@NickLilja) March 5, 2019
Also, new personal record for coldest thunderstorm I've ever experienced.
It is 36F. pic.twitter.com/qNQjoV5Vzb
Also important, is when I said the other day on air that the coldest thunderstorm I’d ever been in was 46 degrees, I forgot to mention the coldest thunderstorm I’d ever seen was the one above – at 36F.
I have seen thundersnow a few times, so I suppose that takes the record for the coldest. In Amarillo, while I was the morning meteorologist at KAMR, I think it was 28F and thunderstorming snow during the 2013 Blizzard.
… Back to the data
As the current system lifts out, the colder low-level air modifies quickly. And then the southerly flow ahead of the next system ushers in warmer-than-freezing air by Sunday evening and into Monday morning.
That warmer-than-freezing air is going to be the part of the atmosphere that melts all the potential snow.
Nick, I really want it to snow, what can I hope for?
You can hope this system glides a bit further south than the current projected path.
The further south, the less likely that the southerly flow in the lower levels established itself as much over our area, leaving us a bit cooler higher up in the atmosphere.
That is – likely – going to be our biggest limiting factor.
That said, there may be a second timeframe where snow may be possible. Monday night and into Tuesday morning as this system lifts out, there may be juuuuuust enough moisture left over in the lower levels of the atmosphere for ice crystals to form and fall.
This wouldn’t be ‘technical’ snow. But it would be frozen and falling.
The Bottom Line
It looks like a very cold rain will fall on Sunday night and into Monday morning. The rain may mix with sleet pellets and snowflakes from time-to-time. You may hear a few rumbles of thunder. And the wind may gust to about 25mph.
And there may be a changeover to all sleet or even all snow across areas near and north of I-20.
But, based on the latest data, it looks like travel problems will be at a minimum for southern Mississippi – aside from the wet roads. And life will most likely be able to continue as normal.
That said, some groups, government agencies, and businesses may choose to alter hours given the potential for adverse weather. But the likelihood of the adverse weather occurring looks pretty low as of now.
