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…
Speaking of warmth, 2016 has been a very warm year.
(The cold of 2014 seems so long ago…)
Back to present. We’ve targeted the middle part of November to finally beginning “bucking” the recent warm trend. This won’t happen overnight and will be a battle of back and forth, initially. Thus, the “step-down” label. To be clear, November, as a whole, will finish much warmer than average. It’s virtually impossible to counter the incredibly warm start. That said, we do anticipate “jabs” of colder air working in here over the next couple weeks. For instance, this weekend will feature lows in the 20s for most and highs not making it out of the 40s Saturday afternoon. (The average low and high at IND Saturday are 37 and 54).
When we look at the AAM forecast (above), we note the westerlies may begin to slow (indicative of the negative values) in the 8-10 day period. This is crucial and, simply put, has to happen for the pattern to begin shifting into more of a position to allow sustained cold to enter the equation. We want to reiterate that this, in and of itself, doesn’t create the cold, but instead allows the pattern to begin shifting away from the Nino-like (warm) regime into more of a La Nina pattern, as a whole. – Hey, you have to start somewhere.
Additionally, the EPO is forecast negative off the GEFS and EPS. (Images courtesy of Weatherbell.com).
Again, this is a cold signal. (Image courtesy of Madusweather.com).
The ensemble data is also beginning to key-in on higher heights (blocking) developing over the top. Notice the significant changes in the overall look to the pattern between now and days 11-16. (Images courtesy of Weatherbell.com).
In summary, and in the face of *most* seasonal data that is screaming warm, warm, warm, we still don’t have any significant changes to our overall thinking of “step-down” mid-November giving way to more sustained wintry-like conditions in the overall sense from the Thanksgiving-Christmas period. Time will tell and only the Good Lord knows what the future holds, but we’ve done far too much work and research to throw the “game plan” in the trash before the game even begins…
While some oppressive heat and humidity will impact our local area to wrap up the work week and head into the weekend, this is a pattern where it’s incredibly difficult to deal with any sort of one particular weather pattern for any time of substance. Looking forward to August, we don’t see this changing. Remember that word we leaned on to begin summer? “Transient” remains the best way to describe the pattern moving forward, as well.
To close, we’ll leave you with a look at the latest PNA pattern. This has been the primary driver of our weather this summer, and it also argues any sort of dry, hot weather doesn’t last. Note the positive PNA returning to close July. This also lines up well with our idea of unsettled times returning…
