January-to-date is running milder than normal across the region- to the tune of 3.3 degrees (F). This is after a frigid open to the month, as you recall.
The second week of the month warmed significantly and continues, overall, for the next week.
The mid-January warmth is attributed to a roaring PAC jet which is currently helping flood the country with temperatures much more like spring than the dead of winter. We continue to forecast 60+ this weekend across central IN.
Winter lovers, have no fear as changes appear to be in the offing as we go through the last few days of January and head into February. The winter so far has featured conflicting signals that continue to try and compete with one another to take hold of the pattern. Can we get these drivers to align in a way that would pull a more persistent trough into the east for the second half of the winter and, ultimately, set-up a sustained cold pattern helping make up for lost time in the snowfall department? Time will tell, but we do note the following late month:
- (+) PNA pattern
- Sudden stratospheric warming event
- High latitude blocking
All are encouraging for a shift back towards a wintry regime. As always, the devil is in the details and we’re skeptical as to the longevity of these signals. “Cautiously optimistic” would be the way to sum up our current feel longer-term into the month of February, but we’re not as bullish on lock and hold cold, wintry conditions at this time as what you may hear from some of our national compadres. Understanding that various drivers can have a different impact mid and late winter as opposed to early is one thing. It’s also important to note that long term modeling has been abysmal as of late and we want to tread through the next couple of weeks with caution to see whether or not the cold drivers can finally take hold.
Needless to say, at least through late month, one can see the significant changes take place at 500mb.
Thursday:
This Weekend:
Next Thursday:
Next Weekend:
The pattern begins in the short-term with a look that will power anomalous warmth through the weekend, along with renewed rain chances Thursday night into Friday (another 1″+ for most), but begins to shift next week towards the colder look. The 2nd (weekend) storm system will be significant and poses a severe risk to the southeast region. Modeling has backed away on the heavy rain threat Sunday, but showers will be around early next week along with very windy conditions (40+ MPH gusts). Blocking is forcing the low south. By the time we get to next weekend, the pattern has done a 180 and in a position to drill unseasonably cold air back into the central and eastern portions of the country.
As far as storms go later in the period, it’s far too early to discuss specifics, but the pattern seems to be one that will promote the chance to get into the act on high-ratio producing clippers. It’s the first time we can say that this year. Time will tell…
2.) Showers will creep north overnight into Monday morning, but shouldn’t amount to much. They will be scattered in nature across central Indiana.
3.) More widespread rain and embedded thunder will develop Monday night into Tuesday morning. This should amount of widespread half inch to one inch totals across the viewing area.
4.) A moist southwest flow will help push a warmer regime northward for the second half of the week. Though warm, we’ll also have to deal with periods of rain as disturbances track northeast. We circle Friday and Sunday as the wettest days and remain optimistic Saturday will feature dry and unseasonably warm conditions (lower-middle 60s). Between the rainy days Friday and Sunday, additional rainfall totals of 1″-2″ seem like a good bet.
5.) The evolution of the pattern just beyond the 7-day period we’ll begin to take on an increasingly wintry look and we remain confident on a flip back to wintry conditions as we roll through the last week of the month. We’ll have to keep a close eye on a storm system in the 8-10 day period. It’s obviously way too early to discuss specifics, but this will be the time the pattern is beginning to turn back towards a wintry regime…
2.) Expanding Snowpack: 65.4% of the country is covered in snow this morning. The cold, arctic high suppressed the winter storm threat south as we alluded to in previous posts. Places across the Deep South that aren’t used to wintry precipitation are waking up to snowy and icy conditions this morning, including MS, AL, GA, SC, and into the Mid Atlantic. Heavier snowfall accumulated across east TN, including 5″-8″ in the high country. Heavy snow also fell through western and central NC and Blizzard Warnings are up in rare areas including VA Beach this morning.
3.) Moderating Temperatures: Our air flow will back around to the southwest and this will help temperatures begin to moderate early next week (around freezing Monday and all the way to around 50 Tuesday). As the moderating trend gets underway, we may have to deal with a brief period of freezing drizzle/ freezing rain Monday evening.
4.) Rainy Midweek: A more significant surge of moisture will arrive midweek and result in periods of moderate to heavy rain Wednesday PM into Thursday. Potential is present for 1″+ during this timeframe.
5.) Weekend Wintry “Fun And Games?” A tremendous battle will take place next weekend between a strong and sprawling arctic high pressure system and the southeast ridge. In between it’ll be fascinating to watch things unfold, and as you’d imagine, that includes Indiana. Despite the southeast ridge flexing it’s muscle, the concern here is that the shallow dense arctic air will “ooze” south and present an icy set-up for portions of the Ohio Valley and Mid West for the weekend. We still have some time to watch this, but the potential of significant icing is very much present for some and this will require a close eye through the week.
This won’t be your standard 10:1 ratio type snow as conditions will be very cold throughout the day Thursday (only around 20 for a high). This will serve to “fluff up” a tenth of an inch of liquid to a couple inches of snow very easily. Secondly, with the cold conditions, it won’t take much snow to create slick and hazardous travel throughout central Indiana Thursday. Please plan to allow plenty of extra time to reach your destination Thursday, both during the morning and evening commutes.
By Day (10), the cold pattern is well established over the Lower 48. This is a coast-to-coast cold signal (heart of the cold centered over the west and central) depicted by the European ensemble, along with other modeling.
Teleconnections support a cold pattern returning.
The agreement amongst teleconnections is nice to see and ups confidence in the overall direction of where this pattern is heading in regards to colder than average times looming. The negative PNA correlates nicely with the SE ridge that continues to make itself heard from time to time over the next few weeks. It should also be noted that the phases of the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) become more of a factor for mid and late winter.
Accordingly, we see the ensemble data flipping to a colder pattern over the upcoming (10) days. Note the low anomalies in the higher latitude regions today (Image 1) versus Day 10 (Image 2).
The pattern developing by Day (10) is one capable of producing another frigid regime- only January style. Cross-polar flow sets up shop and, unlike, December, some blocking is noted, as well. This can help the mean storm track shift further south. (Bye-bye Great Lakes cutters, though Mid Western and Ohio Valley Snow Lovers will find a new worry in the form of suppression potential ;-)). Individual storms will have their respected challenges, as always. As a whole, it’s a very cold, stormy look and a pattern capable of leading to an expanding snow pack across the Lower 48.
We note ensemble data is suggesting high latitude blocking tries to develop towards Day 10. Recall this was the missing ingredient in the bitterly cold blasts of air that occurred during the first few weeks of December. Both the GEFS and EPS agree on the increasingly blocky look to the pattern by Day 10. This would help drive a cold, stormy pattern by early January. Instead of storms cutting, we would see more suppression. With a “stubborn” southeast ridge, things could get interesting across the Ohio Valley from a wintry perspective….
We don’t want to jump the gun, but it the positives can “hook up” over the pole, we stand the chance of locking into a rather lengthy cold, snowy regime as we rumble deeper into the heart of winter.
Summary: A rather mild regime remains as we rumble through Christmas before trending more seasonable next week. From a wintry perspective we need to continue to keep an eye on the period around New Year’s Eve/ Day. Confidence continues to increase on the potential of a return of arctic air come early January.
This is, of course, is in stark contrast to December 2015.
As we move forward, an active pattern awaits between now and the end of the year. This comes after a few days to catch our breath, including moderating temperatures leading up to Christmas.
Christmas Eve will feature overcast skies with areas of fog and drizzle, but the majority of the concentrated rain should fall south of the region. Santa’s ride into central IN should be uneventful, weather-wise.
Temperatures will fall through the day Monday and we should run much closer to seasonable temperatures next week. A couple of additional storm systems will have to be monitored for rain and snow prospects the middle of next week and again around New Year’s Eve/ Day. Initially, we’ll be rather mild, but there may be more in the way of cold air readily available to make the storm system around New Years “more interesting” from a wintry perspective.
