I mentioned that I am in the process of putting together a detailed forecast for the rest of January going into February. I am still convinced that our winter is about to get active across the southern United States and eventually up the East Coast. If the potential ice storm doesn’t come to fruition this weekend, then I plan on releasing that detailed forecast this Sunday at 2 pm ET.
Before I point out something about the coming pattern, I can’t stress enough how everyone doesn’t need to be outside for long periods of time tonight and tomorrow if you’re in the central and eastern United States. This is some serious cold! Remember to bring your pets inside, and keep a check on the elderly and sick. Hopefully schools will be delayed or closed tomorrow, but if for some reason they’re not, dress your kids in multiple layers.
Below are the projected temps by the 4 km NAM for tomorrow morning. These are actual temps, and wind chills will be much worse.
Active and Stormy Pattern Setting Up:
I have mentioned dozens of times over the course of the last several months that I believed that a very wet (and snowy/icy) pattern would be shaping up for the southern U.S. and potentially up the East Coast this winter. You may also remember me mentioning that a very active sub-tropical jet would be setting up across the southern U.S., and that we’d be dealing with a split-flow pattern. I’ll explain what all of that means.
A jet stream is a narrow-band of fast-moving winds in the upper-levels of the atmosphere (6 to 9 miles above the surface). The Pacific jet stream has been extremely active so far this winter. In fact, it has been so strong that it has been responsible for pushing Pacific air over the United States and initially cutting off our Arctic air source.
While the Pacific jet stream is still very strong, a split-flow pattern is about to begin setting up over the western United States. Basically what that means is that the jet stream will split into two separate jet streams with a southern jet (the sub-tropical jet) and a northern jet (a polar jet). Later this month, I expect a more amplified polar jet to set up over the central and eastern United States (basically this will pump Arctic air over those regions) and for the polar jet to interact with the active sub-tropical jet. Remember, the active sub-tropical jet stream will be responsible for transporting moisture across the southern United States and up the East Coast.
To help you better visualize this, I included the GFS ensemble for the middle of next week. Where you see the brighter colors on the map is where the jet streams are located. Those dark reds and bright purples indicate very strong winds in the upper-levels of the atmosphere. I included arrows to outline the sub-tropical and polar jet streams.
For those of you that have studied meteorology, you can see that this has a very “El Nino look” to it. This is a pretty progressive pattern (for now), but my point is that the moisture is going to be available across the South. If you get just enough cold air in place, then you know what that means. We’re going to have a very close call this weekend with the potential ice storm threat, but it will all come down to timing. Can you imagine if we would have had a huge winter storm this week with all of that cold?
I can’t help but think that with what’s currently taking place in the stratosphere at the North Pole that the cold air is really going to be unleashed. For the naysayers going around talking about how winter is over, I honestly just don’t see it. I truly believe that the East Coast and southern U.S. will have several winter storm chances this season.
On a side note, residents up towards the Great Lakes need to watch things, too. With those lakes as warm as they are, the lake effect snow machine could really get going later in the month going into February. Like I mentioned above, if we don’t have too much going on with the weather this weekend, then I’ll have more details then.