The MJO is rolling right into the notorious cold (for this time of year) phase 3 as we open up the new year.
The composite analog for phase 3 in January from an upper air and surface temperature anomaly standpoint:
Ensemble guidance shows the widespread colder than normal temperatures overspreading the country. Like clockwork, this is almost identical to the Phase 3 analog above.
After a quiet week, we’ll watch 2 storms in the 5-10 day period. The first comes along next weekend. While still far too early to get detailed, this one does have potential to serve up some wintry mischief to the Ohio Valley, including central Indiana.
The second storm follows and it’s behind this feature that more of a truly arctic air mass will get involved in our pattern.
The pattern will stay busy as the arctic air presses in. At the same time, note the Greenland block beginning to form. Winter weather enthusiasts have to be chomping at the bit by that 10-15 day look. Needless to say, we can expect a rapidly expanding snow pack across the Lower 48 over the next couple weeks.
Thereafter, all eyes will remain on the MJO. Do we roll into the “null phase,” such as what the European suggests or swing through the traditionally mild/ warm phases such as the American guidance portrays? Stay tuned…
First, if you didn’t have a chance to see our thoughts after the European Weeklies came in, you can check that out here.
After the snow across portions of western and southern Indiana the past couple days (thank you for all of the reports, by the way), the next feature we’re tracking has to do with a clipper system that will dive southeast across the upper Mid West and into the Ohio Valley New Year’s Eve. This will certainly be moisture-starved, but should have just enough to work with to generate snow flurries and scattered snow showers by late Sunday morning, continuing in off an on fashion into the afternoon and evening.
A weak clipper system will offer up a few snow showers New Year’s Eve.
That’s really all there is to track, locally, over the upcoming 7-day period. The predominant storm track will shift off to the south during this time frame as an active, El Niño induced, southern jet takes hold. The one potential feature of interest is out towards the end of next week. We’ll keep an eye on it, but as of now, it looks like the phasing of energy will take place just a little too far east for anything of “excitement” here.
Temperatures will continue to cool closer to seasonal averages and perhaps a bit below normal over the upcoming 10-14 days. Greatest cool anomalies will be located across the western and southern tier during this timeframe.
Updated with European Weekly thoughts 12/29/23 @ 7:09a
There’s no reason to change any of our thoughts concerning how things play out over the next 24 hours with our upper level low pressure system. That idea from yesterday is available here. In short, it still appears as if parts of west-central Indiana are still greatest at risk of seeing light wet snow accumulation (of course some of our friends in southwest Indiana are already enjoying waking up to snow on the ground this morning).
As we look ahead to the upcoming 3-4 weeks (will add to this post later tonight after having a chance to see the updated Euro Weekly teleconnections), it appears as if we’re heading right towards more of a predominant El Niño regime with an active southern storm track and most persistent cold, relative to average, taking up residence across the southern tier. The updated JMA Weekly model portrays this best over the course of the upcoming 28 days:
Modeling continues to struggle with the MJO evolution over the upcoming 2 week period. While this doesn’t impact the idea of colder times in the short-term period, it does have great implications beyond mid-January. The kind of amplitude shown off the American guidance (image 1 below) would threaten to deliver a much warmer than average period, locally, beyond mid-month. Meanwhile, the European (image 2 below) continues to suggest a collapse into the neutral phase.
The 2 primary other pattern drivers include the PNA and EPO through mid-January. Beyond this point, we’ll start to incorporate the likes of the NAO and AO into our forecast (hence another reason why we’re interested in seeing how the Euro Weeklies show this later today).
Simply based on how the PNA/ EPO combo is forecast, the first week would open with cooler temperatures transitioning into the region and then we would likely see moderation in the week 2 to early week 3 timeframe.
Week 1
Week 2
While we’re certainly transitioning to a cooler and more active pattern over the upcoming couple weeks, compared to where we’ve been to this point in meteorological winter, it’s not yet to a point where anything looks excessively cold or, for that matter, snowy.
That doesn’t mean that there won’t be a couple storms to track that could offer up some meaningful winter weather potential here, but I just don’t see a sustained cold, snowy pattern taking foot through mid-January. Beyond that point, we’ll have to monitor which more extreme solution plays out. Based on everything going on by that point, it’s still likely to be a situation where either more persistent (and significant) cold or warmth develops.
European Weekly update 12/29/23
The new European Weeklies show a warmer option for the 2nd half of January, but contradict their own teleconnections during this time frame. The model goes to a strong negative AO, positive PNA, negative NAO, and a neutral EPO. Of course we’ll have to see what the MJO ultimately ends up doing but that combo strongly argues for the colder option for the 2nd half of January.
Updated 12.23.23 @ 7a When we look at our current mild December, I suppose it should really come as no surprise, especially given our research that began early September with…
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We open the period with widespread milder than normal temperatures in the 1-6 day period. Greatest anomalies are centered over the upper Midwest. Note the step down to a pattern, locally, that’s more seasonable if not slightly cooler than normal to close the year and open 2024. That’s the emphasis we want to drive home- though turning colder, we’re not in the camp that our immediate region will have to deal with any sort of arctic air anytime soon.
Days 1-6
Days 6-11
Days 10-15
You know we’ll be keeping close eyes on the Madden Julian Oscillation over the next few days. Should the American guidance come to fruition, then a warmer pattern is certainly alive and kicking after the cooler pattern to open January. Interestingly this morning, early trends are more in favor of the European camp, but it’s still early and we’ll need to monitor closely through the Christmas holiday.
American guidance isn’t as bullish moving into Phase 3 early January with the overnight update.
In the shorter term, morning showers will transition to more of a widespread light rain across the northern half of the state later this afternoon and tonight. Some northern Indiana rain gauges could surpass 0.50″ during this time period from “round 1” of more widespread rain.
Pesky light showers will be around Saturday, but this will be more of a nuisance than anything else. Widespread measurable rain isn’t anticipated. We then flip the calendar to Christmas Eve and the forecast continues to improve. We even anticipate some sunshine to couple with the unseasonably mild air and breezy southerly winds. Highs approaching 60° can be expected as Santa loads up his sleigh.
More widespread rain arrives Christmas Day, especially by late morning and during the afternoon. This is the timeframe when we expect greatest coverage and heaviest rainfall rates of the period. Storm total rainfall of 0.50″ to 1″ still looks like a good bet.
Colder air works in behind the storm and left over “wrap around” precipitation will begin to mix with and change to snow Thursday.
The downhill slide to more seasonable and slightly colder than normal temperatures continues as we close out the year…
