GET READY FOR A WINTRY ROLLAR COASTER RIDE!
THIS YEAR’S OVERALL PATTERN: Heading into this year, the signals which foretell cold or mild are once again in a “weak” state. This means that the weather pattern will be harder than usual to predict from a seasonal standpoint. For this reason, the overall consensus is that we should expect
a lot of variability during the winter months, as opposed to either cold or warm air dominating the entire landscape. What’s noticeably different about this year versus last year however is the presence of an El Nino state in the equatorial Pacific Ocean waters;
as paltry as it is right now, it will still be able to add an element of more storminess to the continental southern and eastern United States by way of inducing an active southern jet stream. Therefore, unlike last year, the prospect of a dry winter around here is less likely than average at this time.
ACCUWEATHER SHOWS A WEAK EL NINO PATTERN:
Add to that the inevitable shots of cold which will come early in a setup like this, and one can reasonably assert that, at this point, the outlook of seeing at least some formidable snow is a bit higher than average. More on this below.
LAST YEAR: By and large, the winter outlooks for 2011-12 were a debacle.
Nearly every weather source out there predicted a cold, snowy winter for the northern tier of the United States. Contrary to this, the northern branch of the Pacific jet stream overwhelmed the pattern, and flooded the lower-48 with incredibly mild air, while at the same time, an area of high pressure dominated much of northeast Canada, keeping bitterly cold air bottled up over Greenland.
A rather minor snow event occurred in mid-January, but thereafter, mild air once again infiltrated and got even more pronounced in late winter/early spring; it all culminated with a historic early spring heat wave across much of the nation that would have done early summer proud!
WHAT COULD GO WRONG? In terms of the various forecasts for this winter, there’s always a danger that, on either side of the ledger – cold or warm—that the pattern locks in to one extreme or the other, making a mockery out of long range prognostications yet again.
Obviously, the most favored outcome to many would be that the mild air can dominate like 2011-2012. But, unlike last year, signs are already indicating that cold weather will be more prevalent in the lower-48 states in the fall. This is, in part, due to the North Atlantic Oscillation -- which has been running in negative territory through much of the summer months; the result of a negative phase is usually a significant harbinger of cold weather in the east in the early winter months.
In addition, instead of either being quickly scoured out or jailed over Alaska or in Northeast Canada, patterns which feature a negative NAO favor the cold having a much better chance to linger. If high latitude blocking in the form of a negative NAO develops for a time, a severe outbreak of cold and/or potential bouts of heavy snow can grip the region for several weeks at a time, much like we saw back in 2010-2011, and in an extreme way during the 2000s – which were by far, the snowiest decade since the 1960s in NYC.
Given the prospect of storminess being on the high side with a weak El Nino and the possible implications of the NAO, the idea that winter could turn downright brutal for a time is something to be concerned with.
Here are some selected winter outlooks from around the web:
Accuweather
The Weather Centre
NOAA
