Category: NAO

Updated 02.27.23 @ 6:15p

Temperatures are running around 7° above normal at IND February to-date, and the first few days of March will also get off to a well above normal start. Winter, as a whole, aside from the bitter pre-Christmas blast, has been absolutely forgettable to most winter weather enthusiasts. I suppose it only makes sense that just as most are ready for “stick and hold” spring weather to show itself, we are seeing the best alignment and most bullish signal for persistent anomalous cold from a variety of pattern drivers all winter long. 😉

Long time IndyWx viewers know that this is the time of year we lean heaviest of NAO impacts, particularly if in a negative state. Latest long range data places the NAO in a negative state for the better part of the upcoming (6) weeks:

This strongly argues for more of a persistent eastern trough, including below normal temperatures and an active storm track, thanks to the busy Pacific pattern.

Secondly, and we really should have started with this one, the Madden-Julian Oscillation is finally set to rotate into the traditionally cold phases (8 and then 1) as we flip the page to the 2nd week of March and beyond. This should eventually translate into a widespread cold pattern, including the East, with an active coast-to-coast storm track continuing. Also note the high latitude blocking emerging as we transition into Phase 1.

Throw in a negative WPO, and this further backs up the widespread cold, active pattern. Similar to the NAO chart to open this piece, the majority of the (6) week period is spent in a negative state. Pattern alignment…

Add in all of this and there’s no wonder the most updated (as of this afternoon) European Weeklies are banging the drum, quite loudly I might add, for a prolonged period of colder than normal weather from mid-March through mid-April. Don’t put away that cold weather gear- or snow shovels just yet…