Category: WPO

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 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/

Dec 16

LR Update Into Mid January; Short Term Focuses On Accumulating Snow Prospects Next Week…

Updated 12.16.22 @ 7:48a

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Permanent link to this article: https://indywx.com/2022/12/16/lr-update-into-mid-january-short-term-focuses-on-accumulating-snow-prospects-next-week/

Mar 02

Winter Isn’t Done Yet…

Updated 03.02.22 @ 7:56p

The Madden Julian Oscillation (MJO) is back in the null, or neutral, phase.

That means it’s time to start leaning heavier on the teleconnection blend. This time of the year, that encompasses all, including the NAO.

As we look over the course of the upcoming 10-14 days, we note rather strong alignment between the teleconnections favoring a return of a cold pattern. That is, of course, after the taste of spring that will continue into the day Sunday (aside from one “speed bump” tomorrow).

We note the EPO, or East Pacific Oscillation, is forecast negative until around the 12th and then back towards neutral. This is a cold signal for the east, relative to average.

The NAO (North Atlantic Oscillation) is forecast neutral through the bulk of the upcoming couple weeks. – Likely won’t have a significant impact on the overall pattern.

The PNA (Pacific North American pattern) is forecast negative through the 13th before trending neutral. This should allow a southeastern ridge to remain in play to at least some degree which suggests a very active storm track into the Ohio Valley. As the colder air pushes east and runs up against the resistance from the southeastern ridge, late season wintry threats loom towards mid month.

Finally, the WPO (West Pacific Oscillation) is forecast strongly negative which also implies cold should try and fight east.

With all of that said above, we note the ensemble guidance (both the EPS and GEFS) brings the trough back into the central and eastern portion of the country as we move out of the Day 1-6 period and suggests it’s far too early to think about putting away those winter clothes, or even the snow removal equipment just yet…

Upper air pattern- March 3-8
Upper air pattern- March 8-13
Upper air pattern- March 12-17

Note the colder than normal temperatures spilling back into the region next week and the week beyond.

We’re likely far from finished with snow or wintry precipitation either…

Permanent link to this article: https://indywx.com/2022/03/02/winter-isnt-done-yet/

Feb 25

Long Range Update: Spring, Is That You?

Updated 02.25.22 @ 5a

As another wintry event comes to an end, most Hoosiers are ready for spring. As we look ahead at the upcoming couple of weeks, there are signs that at least a “taste” of spring awaits. But, as is typically the case, there are contradicting signals.

The consensus from our big player teleconnections would suggest a warm-up (compared to normal) in the 5-10 day period, but note that the trends are favorable for cooler than normal temperatures thereafter.

Ensemble guidance shows the transition over the upcoming couple weeks.

The Madden Julian Oscillation (MJO) argues that eastern warmth should come back with a vengeance towards mid-March after the potential of a brief cooler setback. We note guidance is in better alignment taking things into Phase 5 and that should result in an expanding eastern ridge between the 10th and 15th.

The JMA Week 2 500mb pattern looks pretty good to me based on the MJO activity. Meanwhile, unseasonably cold air is likely to dump into the West and we’ll have ti monitor thing the pattern drivers closely once passed mid-month for the possibility of colder air to ooze east.

The transitional theme to the overall pattern should promote wetter than normal conditions over the upcoming 14-16 days as a whole.

Permanent link to this article: https://indywx.com/2022/02/25/long-range-update-spring-is-that-you/

Jan 28

Long Range Update: Pattern Evolution Through February…

Updated 01.28.22 @ 7:32a

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Permanent link to this article: https://indywx.com/2022/01/28/long-range-update-pattern-evolution-through-february/

Jan 24

VIDEO: Light Snow Ends This Morning; Turning Bitterly Cold For Midweek…

Updated 01.24.22 @ 7:37a

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Permanent link to this article: https://indywx.com/2022/01/24/video-light-snow-ends-this-morning-turning-bitterly-cold-for-midweek/

Jan 12

VIDEO: Significant Weekend Questions; Bullish On A Very Cold Close To January…

Updated 01.12.22 @ 7:23a

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Permanent link to this article: https://indywx.com/2022/01/12/video-significant-weekend-questions-bullish-on-a-very-cold-close-to-january/

Jan 01

The Long Awaited Shift To More Winter-Like Conditions Begins…

Updated 01.01.22 @ 8:06a

From our family to yours, here’s wishing you a happy, healthy, and prosperous 2022!

As we embark on a new year, a new weather pattern will take hold. Consider the drastic difference of going from a regime that’s been much more October or November-like (December ‘21 temperatures ran a stunning 8.8° above average on the month) to one that will feature a series of reinforcing blasts of cold air- at what’s traditionally the coldest time of the year.

Temperatures ran well above normal in December from the Plains into the Ohio Valley, Great Lakes, and East.
A flip in the overall regime will drive cold over the upcoming couple weeks into the very place December was warm.

The reasons behind the shift in the pattern start with the MJO moving into Phase 8.

Can we amplify things into Phase 1 towards mid month? The American modeling suggests that’s on the playing field. Meanwhile, the Euro wants to take things towards the neutral phase. If we can swing into Phase 1, the ante would be upped for “locking” the cold in for the 2nd half of the month.


As it is, the majority of teleconnections are being “forced” (byproduct, in my opinion, of the MJO) into more favorable phases for cold. Remember, only a couple days ago this wasn’t being shown, but as the data is understanding the driving force (MJO movement), the EPO is joining the PNA and WPO colder camp. I would expect the AO trend to follow suit in the week ahead.

More on all of this in the AM, including the opportunities for snow and wintry precipitation (more than the novelty level stuff we’ll deal with early Sunday AM) in the weeks ahead…

Permanent link to this article: https://indywx.com/2022/01/01/the-long-awaited-shift-to-more-winter-like-conditions-begins/

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