Category: NAO

Feb 27

Spring “Tease” Just That; Long, Long Road Ahead…

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…

Permanent link to this article: https://indywx.com/2023/02/27/spring-tease-just-that-long-long-road-ahead/

Feb 24

LR Update: Prolonged Period Of Unseasonably Cold, Active Weather On Deck…

Updated 02.24.23 @ 6a

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Permanent link to this article: https://indywx.com/2023/02/24/lr-update-prolonged-period-of-unseasonably-cold-active-weather-on-deck/

Feb 21

VIDEO: Wholesale Pattern Change Just As Most Are Wanting Spring; Tracking 2 Storm Systems Over The Next 7-Days…

Updated 02.21.23 @ 7:45a

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Permanent link to this article: https://indywx.com/2023/02/21/video-wholesale-pattern-change-just-as-most-are-wanting-spring-tracking-2-storm-systems-over-the-next-7-days/

Feb 20

VIDEO: Timing Out When Rain Returns; Updated Look At The Longer Range Pattern Drivers…

Updated 02.20.23 @ 8:37a

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Permanent link to this article: https://indywx.com/2023/02/20/video-timing-out-when-rain-returns-updated-look-at-the-longer-range-pattern-drivers/

Feb 16

VIDEO: Strong Storms Downstate This Afternoon; Longer Range Musings…

Updated 02.16.23 @ 8a

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Permanent link to this article: https://indywx.com/2023/02/16/video-strong-storms-downstate-this-afternoon-longer-range-musings/

Feb 13

More Of A Wintry Feel Set To Return As We Get Ready To Open Meteorological Spring?

Updated 02.13.23 @ 7a

First and foremost, we’ll have a fresh video discussion posted later this evening with updated thoughts on the chances of a few stronger storms up this way Thursday.

With only a couple weeks left in “meteorological winter,” many are asking is this it for the little cold and snow we’ve seen, relatively speaking? The short, easy answer to that question is “no,” but we wanted to dig in further and see if there are any reasons to buy into more of a prolonged period of colder than normal conditions on the horizon.

February is running close to 5° above average month to date. A large reason behind the warmth is thanks to the MJO rolling through the warm phases (remember, Phases 4 and 5 in February features large-scale eastern on CONUS wide upper ridging, as shown below).

That said, as we rumble through the few weeks, model data suggests the MJO will race towards traditionally colder phases (and stormy, too) as we close February and head into the first month of meteorological spring.

Draw your attention to the purple in Phase 8. A cycle through this phase at late February and March would bring a period (and more than just a day or two) or substantially colder than normal temperatures into the region.

That then begs the question, what comes of the NAO (North Atlantic Oscillation) and the PNA (Pacific North America pattern). Let’s take the latter first. I think it’ll be hard to completely shake the southeast ridge in this pattern. Despite the Nina fading, the influence on the greater regime still is quite pronounced and in some shape or form, I believe the negative PNA holds. That said, we do note the longer range guidance flipping the NAO negative as we get into March. Note the GEFS Extended below (should be noted that the European Weeklies also develop a negative NAO in March). Long time followers of IndyWx know as much as I don’t get excited about the NAO influence in Nov. or Dec., I jump all over this particular teleconnection late winter and spring. Why? In my research, it’s apparent the impacts and longer term effects of a negative NAO are much stronger across the eastern half of the country in Feb through early April.

Despite the resistance that will likely continue in some shape or form from the negative PNA, should we, indeed, see the MJO and NAO move into the expected phases shown above, this will set our region up for a 2-3 week period of colder than normal and stormy conditions just at the time most are wanting spring to come on with authority. Time will tell!

In the meantime, we look forward to having a fresh video discussion posted later this evening around the prospects of Thursday storms. Enjoy your Monday!

Permanent link to this article: https://indywx.com/2023/02/13/more-of-a-wintry-feel-set-to-return-as-we-get-ready-to-open-meteorological-spring/

Feb 09

MJO And Other Drivers Aligning For Cold Close To Meteorological Winter; Open To Spring?

Updated 02.09.23 @ 8:53p

After a bitter Christmas period, the “snap back” came on with authority. The mild start to the year has carried into February. A look at the past (30) days:

Despite multiple attempts, the cold “jabs” haven’t had any staying power. In the short term (upcoming 10-14 days), an overall milder than normal regime will carry the day.

With that said, longer range teleconnections are providing clues that the pattern may, indeed, begin to resemble a more sustained colder than normal temperature regime by late February, continuing through the bulk of March:

Negative NAO:

Negative WPO:

Negative AO:

Negative EPO:

Then, perhaps most significant, the MJO is showing signs of cycling in Phase 8 to close February and open March.

Both periods feature a cold, to much colder than normal, pattern in Phase 8:

MJO Phase 8: Feb

MJO Phase 8: March

Perhaps the latest European Weeklies for late Feb through late March are onto the correct idea…

Permanent link to this article: https://indywx.com/2023/02/09/mjo-and-other-drivers-aligning-for-cold-close-to-meteorological-winter-open-to-spring/

Feb 01

VIDEO: Spring Tease Into Mid-February, But Be Careful What You Wish For As Late February And March Nears…

Updated 02.01.23 @ 6:04p

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Permanent link to this article: https://indywx.com/2023/02/01/video-spring-tease-into-mid-february-but-be-careful-what-you-wish-for-as-late-february-and-march-nears/

Jan 29

VIDEO: Light Wintry Precipitation Across The Central, Southern Portion Of The State; Longer Range Pattern Update…

Updated 01.29.23 @ 5:35p

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Permanent link to this article: https://indywx.com/2023/01/29/video-light-wintry-precipitation-across-the-central-southern-portion-of-the-state-longer-range-pattern-update/

Jan 19

February And Early March Long Range Discussion…

Updated 01.19.23 @ 6:15p

Our short-term products will continue to handle the snow threats this weekend and next week. In short, we have no changes to our thoughts on either of those from this morning. The 2nd storm has potential to be something much more significant, but we need to give it another 2-3 days before putting a forecast in concrete, especially this winter.

As for the longer range, a more seasonably cold brand of air is expected as we put a wrap on January, but I’m not willing to go further than that to suggest anything close to “bitter” cold is on deck- certainly given the time of the year. It’ll feel much colder, especially considering just how warm it’s been of late, but I just don’t see anything overly cold on the horizon, compared to normal.

Thereafter, the pattern drivers suggest a warmer than normal pattern will return. “Transitional” anyone? While I can’t say we’re looking at anomalies as great as what we’ve seen so far in January, I do think early and mid February will feature above to well above normal temperatures before colder than normal trends take hold late February and into early March.

The updated European Weeklies mirror the new JMA Weeklies and we see no reason to argue given the movement and overall alignment between the EPO, PNA, NAO, and AO.

Week 2

JMA Weeks 3/4

European Weeklies: Week 3


European Weeklies: Week 4


As we get out towards the latter part of February (around or after the 20th), the teleconnections mentioned above, that will likely promote the relatively warm conditions, will begin to turn around and drive a colder close to the month and open to March. In fact, there are signs the coldest anomalies of the entire winter (compared to average, not in the “absolute” form) will await for this period, and potentially continue into a good chunk of March, especially if the MJO amplitude continues and we add in a negative NAO. (I know, I know- remember that I’m only the messenger).

In the meantime, we also agree with the above normal precipitation pattern painted throughout the upcoming few weeks between the updated Weekly products.

In this active type pattern, despite the lack of bitterly cold arctic air, plenty of snow is likely still yet to fall this winter. In fact, despite the slow start, I wouldn’t be shocked if snowfall amounts end up being pretty dang close to seasonal averages with this type pattern (give or take a few inches). The ultimate irony will be if the bulk of that falls in March…

Much more in the morning around the Sunday and Tuesday-Wednesday snow threats!

Permanent link to this article: https://indywx.com/2023/01/19/february-and-early-march-long-range-discussion/

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