Category: Forecast Discussion

Updated 12.23.23 @ 3:04p

The stage has been set for some time concerning late December and the first week to 10 days of January. There are no changes on our ideas concerning that timeframe. In short, a colder (certainly from where we’ve been as of late, and slightly below the average), and stormy evolution sums up that period.

The timeframe now in question has to do with mid and late January, after what sure looks to be a 5-7 day period of moderation. Unlike what we’ve outlined for late December and early January, the second half of January is likely to feature more in the way of a case of “extreme and nothing in between” type pattern. As outlined in Thursday’s long range post, up to this point, modeling has a couple of different takes on the aforementioned period. The American guidance suggests a repeat of well above normal temperatures and a general lack of winter weather looms with an MJO look poised for the classic warm phases.

You likely don’t need us to remind you of January and February last year. Indianapolis ran a whopping 8.1° above normal through the first couple months of the year.

The reason? An amplified MJO rolling slowly through the Phases 3, 4, and 5 before getting into the colder phases late February and into March.

Back to present day, the American guidance, though slowly backing off from the aggressive idea from a couple days ago, suggests this is once again on the table. Should that come to fruition, mid January would feature well above normal temperatures yet again.

As the great Lee Corso famously coined, “not so fast, my friend.” The European guidance collapses the MJO into the null, or neural phase, before getting into the warm phases. While a period of moderation still will likely follow the chilly open to January, should the Euro idea be correct (and we suspect it is- more on that below), an eventual recycling through the cold phases would likely ensue late January into early February.

By this point, guidance is also beginning to align on other important pattern drivers. Remember, by mid January, we really start to lean in on what the NAO and AO are doing. That’s certainly not to say we don’t pay attention to the PNA and EPO- just that the AO/ NAO can have greater influence on the regime into early spring. Of course, the MJO remains king.

What’s interesting is that each respective “driver” positions itself in a manner that argues cold should rule during the late January and early February period.

Should that MJO circle back into the traditional cold phases, look out. The window will open for a period of true arctic air getting involved with the pattern given the other pattern drivers above. – Target period would be late January (after Jan. 15th) and into early February.

Given what’s out there for the taking, it’s certainly not a pattern for the faint of heart. Buckle up!