Category: EPO

Jan 01

Couple Thoughts On This Weekend And Next Week’s Storms; Colder Trends Build Long Term…

Updated 01.01.24 @ 6:41p

I hope you and your family are enjoying an incredible New Year’s Day! What a game we have on our hands at halftime in the Rose Bowl.

I post this in flight back to home base from ushering in the new year in the beautiful Berkshire mountains. Our regularly scheduled client video discussions will return tomorrow morning. I trust you’ve been following along with both short and long term pattern ideas daily over the past week.

The immediate term opens with quiet and unseasonably calm conditions while the end of the upcoming 10-day stretch will end much colder. The transition between start and finish will turn much more hectic around these parts as we track not one, but two storm systems between this weekend and early next week. While there’s no doubt we’ll trend colder than average by Day 10, questions abound with just how cold we go. Should we get a snowpack down, subzero is on the table.

Speaking of the aforementioned more “hectic” pattern, this kicks into gear over the weekend. While modeling likes more of a suppressed track at this distance, thinking here is that guidance will start to pick up on a more organized northern piece of energy, or surface low reflection, that will accompany the primary Gulf low. I suspect a secondary, organized, shield of precipitation into the OHV region Friday night into Saturday. Will that be enough to put our neck of the woods into a winter storm risk during this timeframe? Too early to call at this distance, but given where the PNA, EPO, and Greenland Block that will be starting to mature, I’d recommend keeping an eye on what will likely be an eventual click or two northwest as the week goes along. It’s likely either a “snow or no” type situation here with storm #1, as opposed to having to worry about rain or mixing issues.

As for storm #2 early next week, our early idea takes the primary low into the OHV before a secondary low “takes over” along the eastern seaboard. The energy transfer likely brings just enough mild air north into the central Ohio Valley to create more of a rain to snow type scenario, locally. The coldest air of the season so far will likely follow in the 10-15 day.

Speaking of the 10-15 day, the look above is an absolute textbook upper air pattern not only for cold, but continued opportunities of winter weather here as we rumble into mid-January. By this point, other long term pattern drivers, such as the NAO and AO (of course to go along with the MJO, PNA, and EPO) will be factored in to where we head not only for the 2nd half of the month, but into late winter and spring. Recent trends certainly suggest the colder options are gaining traction. Today’s European Weekly update reflects a more persistent stretch of high latitude blocking I can remember o/ the past few winters. This ups the ante for a stormy stretch into and through the heart of winter. Given the longer term NAO and MJO look, I’d suspect the colder threat (relative to normal) is on the table into spring this year.

Much more in the AM! Make it a great evening!

Permanent link to this article: https://indywx.com/2024/01/01/couple-thoughts-on-this-weekend-and-next-weeks-storms-colder-trends-build-long-term/

Dec 28

Snowy At Times For Some; Updated Long Range Thoughts…

Updated 12.29.23 @ 7:09a

Updated with European Weekly thoughts 12/29/23 @ 7:09a

There’s no reason to change any of our thoughts concerning how things play out over the next 24 hours with our upper level low pressure system. That idea from yesterday is available here. In short, it still appears as if parts of west-central Indiana are still greatest at risk of seeing light wet snow accumulation (of course some of our friends in southwest Indiana are already enjoying waking up to snow on the ground this morning).

As we look ahead to the upcoming 3-4 weeks (will add to this post later tonight after having a chance to see the updated Euro Weekly teleconnections), it appears as if we’re heading right towards more of a predominant El Niño regime with an active southern storm track and most persistent cold, relative to average, taking up residence across the southern tier. The updated JMA Weekly model portrays this best over the course of the upcoming 28 days:

Modeling continues to struggle with the MJO evolution over the upcoming 2 week period. While this doesn’t impact the idea of colder times in the short-term period, it does have great implications beyond mid-January. The kind of amplitude shown off the American guidance (image 1 below) would threaten to deliver a much warmer than average period, locally, beyond mid-month. Meanwhile, the European (image 2 below) continues to suggest a collapse into the neutral phase.

The 2 primary other pattern drivers include the PNA and EPO through mid-January. Beyond this point, we’ll start to incorporate the likes of the NAO and AO into our forecast (hence another reason why we’re interested in seeing how the Euro Weeklies show this later today).

Simply based on how the PNA/ EPO combo is forecast, the first week would open with cooler temperatures transitioning into the region and then we would likely see moderation in the week 2 to early week 3 timeframe.

Week 1

Week 2

While we’re certainly transitioning to a cooler and more active pattern over the upcoming couple weeks, compared to where we’ve been to this point in meteorological winter, it’s not yet to a point where anything looks excessively cold or, for that matter, snowy.

That doesn’t mean that there won’t be a couple storms to track that could offer up some meaningful winter weather potential here, but I just don’t see a sustained cold, snowy pattern taking foot through mid-January. Beyond that point, we’ll have to monitor which more extreme solution plays out. Based on everything going on by that point, it’s still likely to be a situation where either more persistent (and significant) cold or warmth develops.

European Weekly update 12/29/23

The new European Weeklies show a warmer option for the 2nd half of January, but contradict their own teleconnections during this time frame. The model goes to a strong negative AO, positive PNA, negative NAO, and a neutral EPO. Of course we’ll have to see what the MJO ultimately ends up doing but that combo strongly argues for the colder option for the 2nd half of January.

Permanent link to this article: https://indywx.com/2023/12/28/snowy-at-times-for-some-updated-long-range-thoughts/

Dec 23

A Tale Of 2 Potential Extremes For Late January And An Early Lean…

Updated 12.23.23 @ 3:04p

The stage has been set for some time concerning late December and the first week to 10 days of January. There are no changes on our ideas concerning that timeframe. In short, a colder (certainly from where we’ve been as of late, and slightly below the average), and stormy evolution sums up that period.

The timeframe now in question has to do with mid and late January, after what sure looks to be a 5-7 day period of moderation. Unlike what we’ve outlined for late December and early January, the second half of January is likely to feature more in the way of a case of “extreme and nothing in between” type pattern. As outlined in Thursday’s long range post, up to this point, modeling has a couple of different takes on the aforementioned period. The American guidance suggests a repeat of well above normal temperatures and a general lack of winter weather looms with an MJO look poised for the classic warm phases.

You likely don’t need us to remind you of January and February last year. Indianapolis ran a whopping 8.1° above normal through the first couple months of the year.

The reason? An amplified MJO rolling slowly through the Phases 3, 4, and 5 before getting into the colder phases late February and into March.

Back to present day, the American guidance, though slowly backing off from the aggressive idea from a couple days ago, suggests this is once again on the table. Should that come to fruition, mid January would feature well above normal temperatures yet again.

As the great Lee Corso famously coined, “not so fast, my friend.” The European guidance collapses the MJO into the null, or neural phase, before getting into the warm phases. While a period of moderation still will likely follow the chilly open to January, should the Euro idea be correct (and we suspect it is- more on that below), an eventual recycling through the cold phases would likely ensue late January into early February.

By this point, guidance is also beginning to align on other important pattern drivers. Remember, by mid January, we really start to lean in on what the NAO and AO are doing. That’s certainly not to say we don’t pay attention to the PNA and EPO- just that the AO/ NAO can have greater influence on the regime into early spring. Of course, the MJO remains king.

What’s interesting is that each respective “driver” positions itself in a manner that argues cold should rule during the late January and early February period.

Should that MJO circle back into the traditional cold phases, look out. The window will open for a period of true arctic air getting involved with the pattern given the other pattern drivers above. – Target period would be late January (after Jan. 15th) and into early February.

Given what’s out there for the taking, it’s certainly not a pattern for the faint of heart. Buckle up!

Permanent link to this article: https://indywx.com/2023/12/23/a-tale-of-2-potential-extremes-for-late-january-and-an-early-lean/

Dec 23

VIDEO: Wet, Unseasonably Mild Christmas Still On Deck; Colder Shift To Close The Year And Open January…

Updated 12.23.23 @ 7a When we look at our current mild December, I suppose it should really come as no surprise, especially given our research that began early September with…

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Permanent link to this article: https://indywx.com/2023/12/23/video-wet-unseasonably-mild-christmas-still-on-deck-colder-shift-to-close-the-year-and-open-january/

Dec 21

LR Update: MJO Will Have “The” Say…

Updated 12.21.23 @ 5:15p We’ll transition to a cooler pattern as we close out the year and open January. The MJO (Madden-Julian Oscillation), EPO (East Pacific Oscillation), and PNA (Pacific…

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Permanent link to this article: https://indywx.com/2023/12/21/lr-update-mjo-will-have-the-say/

Dec 19

VIDEO: Pattern Drivers Align For Late Month/ Early January Evolution; Periods Of Wet Weather Returns For Christmas…

Updated 12.19.23 @ 6:55a “Number busting” cold is greeting us out the door this morning. Heavier cold weather gear will be required today, despite sunshine returning. An unsettled, but milder…

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Permanent link to this article: https://indywx.com/2023/12/19/video-pattern-drivers-align-for-late-month-early-january-evolution-periods-of-wet-weather-returns-for-christmas/

Dec 18

VIDEO: Snow Squalls Inbound; Gloomy Christmas Weather And A Look Ahead To A Pattern Shift To Close The Year…

Updated 12.18.23 @ 7:49a Snow squalls will become widespread in the coming hours along with gusty winds and falling temperatures. Allow extra time when traveling today as we anticipate road…

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Permanent link to this article: https://indywx.com/2023/12/18/video-snow-squalls-inbound-gloomy-christmas-weather-and-a-look-ahead-to-a-pattern-shift-to-close-the-year/

Dec 17

Long Winded Sunday Manifesto…

Updated 12.17.23 @ 8:52a

An area of low pressure and associated cold front will continue to move east across the state this morning. Morning showers will come to an end from west to east over the next couple of hours. Speaking of rain, most area rain gauges picked up around half an inch of precipitation overnight. (Thank you for all of your reports)!

Meanwhile, our big coastal low will continue to deepen on its’ journey north along the eastern seaboard over the next 24 hours. Major impacts from high surf, heavy rain, and strong winds can be expected up and down the East Coast, along with significant airport impacts Monday. – Certainly not the start to the pre-Christmas week of travel many may hope for. As colder air pours in on the backside, a heavy, wind-whipped snow event will unfold from the high ground of those beautiful east TN and western NC mountains, up into the interior portions of the Northeast.

Surface Map Sunday Morning

Back here on the home front, we still anticipate a piece of upper level energy to accompany a brief “jab” of arctic air to open up the last work week before Christmas.

This will help snow showers develop Monday morning with some locally intense snow squalls impacting the region late morning through the afternoon. These squalls will be most widespread north and east of the city, itself, but even into Indianapolis, I’d anticipate a couple heavy bursts of snow and briefly reduced visibilities Monday. While a dusting to perhaps as much as a half inch of snow is all we can expect across immediate central Indiana, areas downwind of Lake Michigan (north-central and northeast Indiana, including portions of east-central Indiana) can expect 1″ to 2″ with locally heavier amounts in spots where more persistent lake bands take hold.

While we’re not envisioning any sort of plowable snows locally, the brief more intense squalls will be capable of producing slick spots at times. Plan to allow extra time to safely reach your destination. Snow removal Clients, salting will be required across central and east-central Indiana Monday.

Snow showers and heavier squalls will increase through the day Monday.

Wind will be the other component Monday, along with falling temperatures. We expect northwest gusts to approach 35 MPH at times. Wind chills will fall into the 10s.

Just as quickly as the snow and wind hits Monday, it’ll leave. High pressure will build in overhead Tuesday allowing sunshine to return in full force. After a cold day, temperatures will begin to moderate through midweek.

An increasingly moist, but milder, southwesterly flow will take hold late week which will lead to increasingly cloudy and gloomy conditions with rain returning. Unfortunately from this distance, it still appears that we’ll remain socked in with clouds and rain at times Christmas along with highs in the upper 40s to around 50. Areas of fog can also be expected at times.

Rain will return Thursday night and remain with us periodically through the Christmas holiday.

Longer term, all systems are “a go” for a more substantial pattern shift towards colder and potentially wintry fun and games as we close out the year and head deeper into January. Model guidance over the weekend has grown more intriguing with not only the idea of a slower MJO rotation through the classic cold phases, and the EPO is also showing more and more signs of going negative.

While still not ready to say we’re primed for any sort of arctic outbreak, the thought here remains that we go slightly colder than normal early January with an active southern stream of the jet. Based off what the EPO and MJO do beyond this point (along with the AO/ NAO combo come mid-month), and the potential of laying a snowpack down will determine how cold we can go beyond mid-Jan.

You don’t need us to tell you that our El Nino is alive and kicking. What’s of interest is the cooler trends that continue in earnest in region 1+2. Should this continue, then the plot will thicken late winter and spring for the possibility of continued colder trends. . .

Permanent link to this article: https://indywx.com/2023/12/17/sunday-manifesto/

Dec 15

VIDEO: Rain Returns Saturday; Interesting Developments With The MJO That Can Have Longer Term Impacts…

Updated 12.15.23 @ 7:41a Our work week will come to a close with unseasonably pleasant conditions. Southerly breezes will help us warm quickly from the middle and upper 20s to…

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Permanent link to this article: https://indywx.com/2023/12/15/video-rain-returns-saturday-interesting-developments-with-the-mjo-that-can-have-longer-term-impacts/

Dec 14

“The Trend Is Your Friend:” Long Range Discussion Into Mid-January…

Updated 12.14.23 @ 7:22a

Right out of the gate, let’s look at the pattern drivers over the course of the next couple of weeks. By now, you know this starts with the MJO. One has to love the alignment of at least quickly moving out of the current warm phases and into the colder phases. By the 28th, both the GFS and European show us emerging into those colder phases.

The thought here is that we sneak into Phase 8 prior to month’s end and then roll into Phase 1 as we get into early January. The respective temperature composites are below.

MJO: Phase 8 December
MJO: Phase 1 January

That leads us to the PNA and EPO. (Remember, we’ll put more weight into the influence the NAO and AO can have on the regime after mid-January).

The PNA, or Pacific North American pattern, remains in a favorable state for eastern cold.

“Positive” PNA composite pattern

However, the EPO doesn’t want to play nice and will put pressure on any sort of sustained, meaningful cold getting involved over the next 10 days- that is until the MJO gets into the cold phases.

The JMA Weeklies show the progression of the upper pattern best, in my opinion, from any of the long range data that’s currently available for the late December-1st half of January timeframe.

Week 1
Week 2
Weeks 3-4

We’ve had several new subscribers of IndyWx.com All-Access over the past couple of weeks so I wanted to take time to drop a direct link to our annual Winter Outlook. As we get set to put a bow on the first month of meteorological winter, there’s no change to our ongoing idea of the winter as a whole here.

I originally thought the shift to a colder pattern would take shape around 12/20 (give or take a couple of days). While that idea appears to be too aggressive, there’s certainly no backing away from the colder pattern progression as a whole, at least from my perspective. The expectation is that we do, indeed, get into the colder phases of the MJO and that sets off the larger global signal that will likely shift the EPO into a colder phase. It’s interesting that the European Weeklies show this exact thing taking shape down the road (once past 1/1).

While we’re not of the thought this evolves into anything frigid (some sort of overwhelming arctic air mass, for example), we do want to double down on the idea of a slightly colder than normal regime taking hold as we get into the new year. The thought here is that this slightly colder than normal pattern will also have staying power through a good chunk of January, given where I believe the MJO will spend the majority of time. What’s also of interest is the energized southern stream beginning to show itself (going to be one heck of a storm roaring out of the Gulf this weekend). I’d imagine we’re only just beginning to see the active pattern take hold and it won’t take much to get a storm or two to try and phase with northern stream energy if we see the evolution take hold that I envision down the road. At the very least, it’s certainly not a boring pattern.

We’ll have more detailed thoughts on the weekend and next week’s pattern in our updated Client video that will be posted a bit later today!

Permanent link to this article: https://indywx.com/2023/12/14/the-trend-is-your-friend-long-range-discussion-into-mid-january/

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