Wednesday: Next Storm

The forecast below is for the Chattanooga area. If you want your region (i.e., Northeast), then please leave a comment below and I will give it my best shot.

Well, after the clouds cleared today, the sun made for a gorgeous afternoon. There was still that fall type feeling in the air though as temperatures stayed in the 50's. And tomorrow promises to be even better with full sunshine and mild temperatures in the 60's! Enjoy it, because we have some major changes coming this way.

The next storm system I am watching will be developing by tomorrow in the Southern Plains with some northern Texas snow and rain elsewhere. This storm is currently in the Desert Southwest but isn't organized at all. We'll have to wait until tomorrow as it heads into the Gulf of Mexico and picks up some moisture. Now on Monday I talked about the fact that the models were all over the place with this storm system. And today, while not nearly as bad, they still have some pretty significant differences...at least enough to make for an "uncomfortable" forecast. The NAM model had been coming into agreement with the GFS, but as of yesterday, it's trying to take this storm up West of the Appalachians as a "Lake cutter", which has been the case just about all winter long. And with the pattern and La Nina, I can very easily see how that happens. The only reason I'm not sticking to that, at least YET, it because most other major models continue to take the storm East of the Appalachians. What's the difference you might ask? Well, if you remain on the Western side of the area of Low Pressure, you are on the "cold side" as well...where the winds come from the North and keep you cooler as the winds around the Low are counter-clockwise, pulling down the cooler air from the north. This is how we get our major snow storms. While that is happening, the low is also pulling up warm air from the South on the Eastern side of the storm. That is why it is critical where the track of the storm is, and also how close the low comes to your area. Typically the worst snows with a storm system occur in what is called a deformation zone where the axis of heaviest snows and convergence occur. A good example of this occured yesterday in St. Louis where the airport received nearly 5" of snow in just 2 hours! Many places received 10-12" by the time the snow ended. This axis of snow is normally a few hundred miles Northwest of the center of low pressure.

Now, what is the current projection? Well, it's still really difficult to say for sure, but right now the most likely track appears to be just to our South heading up into the Carolinas. Normally this would be a classic setup for snow, but there are several things that will play against us this time around. For one, the cold air once again looks to come in too late, and there won't be any cold air ahead of the storm. Obviously that is the most crucial ingredient you need for a storm. Cold air prior to the storm makes all the difference. Granted, if the storm is strong enough it can pull down cold air in time to switch over to snow, and there is still a chance that could happen, but I'm just not seeing much snow right now. While some snow showers could occur, accumulations look minimal at best. But I will keep an eye on this as the setup IS there for a potential snowstorm, but it doesn't look like all the ingredients will come together at the right time for a substantial amount. Anywhere from Memphis to Nashville and Northwest of that up into Kentucky, Ohio, etc. could be in for it though...they will be closer to the cold air source and could see a good amount of snow if things come together in time. But for us, I think the rain should arrive sometime around early Friday morning, but I'm seeing a rather big dry slot occuring though during the afternoon. So we should see a few hours of rain, but the afternoon just looks cloudy, but dry at this point...or at least in my opinion. Now there could be some wrap-around moisture on the back side which is typical for the lows, but there doesn't appear to be very much of it with this storm right now. So expect some rain showers/flurries Friday night into Saturday.

Now, all of this is based on current projections and could change very easily as more model data comes in. Obviously it is very difficult to make a forecast when the models are all over the place, but hopefully they will start coming to a concensus here shortly...or at least a better concensus.

What about Saturday? Well, it looks VERY chilly to say the least, with temperatures perhaps not getting out of the 30's for highs.

I'll have an update out shortly...after looking at tonights 00z runs, I'll make a short post on whether or not I think the current forecast is on track or not.

Till then, take care.

BTW: In case any of you Northeastern folks are reading, I think that this will be an inland runner for you guys as well. But, the cool thing about weather is the fact that it can always change! But I won't write about it unless someone asks me too simply because I do not know how many people from the Northeast, if any, read this.

~Jordan