We haven’t had a major snowstorm in the Cumberlands this winter … and, yet, it has been a relatively snowy winter overall, with multiple wintry weather threats and small snowfalls.
However, we may see the threat for additional snow placed on hold for a while, as we move into a warmer pattern for the next couple of weeks after a cold start to the week.
Quite a bit was said about the favorable teleconnections and the threat associated with them. Some of those teleconnections will remain favorable for winter weather in this part of the world, while others are moving into unfavorable phases that will help offset the possibilities of cold and snowy weather.
The North Atlantic Oscillation and Arctic Oscillation, explained in a bit more detail in previous posts, will remain in their negative phases for the next couple of weeks. That’s where they need to be for us to see increased chances for cold and snowy weather in the Mid-South region. However, the Pacific North American ridge index is about to go negative, which is not a phase that correlates to cold and snow in the Southeast. Without ridging in the eastern Pacific region, we’re more likely to see atmospheric heights pumped up over the eastern U.S. while cold air intrusions from the northern latitudes settle into the western U.S.
That means for the interim, conditions will be better for wintry weather in the Pacific Northwest than in the Southeast. We’re still going to have an active storm pattern on this side of the country, but it looks like we’ll lose our cold air source for the next couple of weeks. The next storm system (late Wednesday night through Thursday) may start with some snow showers, but we’ll see the bulk of the precipitation fall as rain, with temperatures warming through the 40s during the day on Thursday.
Warm is a relative term, of course. While the last half of January certainly looks milder than the first half, it’s not like we’re going to see short-sleeve weather. The GFS computer model is currently showing temperatures generally in the 40s and 50s for afternoon highs the next two weeks. The current run of the GFS does try to sneak in some upper 50s and low 60s for the last of January or first of February, but that’s so far out that we can’t put too much stock in that.
The ECMWF model is a little colder than the GFS, but it is basically a different version of the same thing: no real cold air showing up here in Tennessee for the next couple of weeks. In fact, the coldest temperature being shown by the GFS model for the next 15 days is 23 degrees…and the model has far more nights with above-freezing temps than with below-freezing temps during that time span.
So is winter over? It’s much, much too soon to say that. There are some indications that we might lose the -NAO/-AO combination as we move from January into February. If that happens, it’ll spell trouble for snow-lovers. However, the key thing to watch right now is the progression of the Madden-Julian Oscillation (MJO). The MJO is a measurement of storminess in the tropics, and how that pattern travels has a major impact on winter weather in other parts of the world. Currently, the MJO is stuck in a somewhat unfavorable phase for wintry weather in the Southeast. If it progresses to a more favorable phase, that could be an indication for colder weather as we move into February. If it retrogrades into a less favorable phase, that could mean an abrupt end to winter.
Either way, it looks like we could potentially be headed for an active spring with multiple threats of severe weather as we enter that transitional period where the cold air intrusions from the north begin to butt heads with warm air intrusions from the south. There’s still plenty of time to watch how that threat develops, however.
Believe it or not: The first half of January was actually warmer than average in Oneida. Our average temperature through Jan. 18 was 34.9 degrees. That’s 1.1 degrees above normal for the month. That’s mostly due to the very warm start to the month, when we hit 60 degrees for a high on both Jan. 2 and Jan. 3. Since that time, we have touched 50 degrees just once (53 on Jan. 5), and our high temperature has been no warmer than 45 degrees for 12 of 15 days (including a high of 28 on Jan. 10, a high of 32 on Jan. 12 and Jan. 17, and a high of 38 on Jan. 11). However, we also haven’t been unusually cold this month. Our low was 15 degrees on Jan. 14 (and we were in the teens on Jan. 13 as well, bottoming out at 16). Other than that, temperatures have generally been in the upper 20s for lows — which is a little milder than usual.