Category: EPO

VIDEO: Updated Thoughts Around This Weekend’s Winter Storm And The Pattern Through March…

Here’s our latest thinking around this weekend’s winter storm and a long range update through the month of March…

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Permanent link to this article: https://indywx.com/2019/02/28/video-updated-thoughts-around-this-weekends-winter-storm-and-the-pattern-through-march/

All-Access Video: Model Differences On Potential Weekend Winter Storm…

Is a weekend winter storm brewing?

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Permanent link to this article: https://indywx.com/2019/02/27/all-access-video-model-differences-on-potential-weekend-winter-storm/

All-Access Video: Looking Deeper Into The Reasons To The Cold Open To March & Mid-Month Changes…

Discussing the reasons behind the frigid open to March and the mid-month changes that await…

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Permanent link to this article: https://indywx.com/2019/02/26/all-access-video-looking-deeper-into-the-reasons-to-the-cold-open-to-march-mid-month-changes/

Frigid Open To March And Late Month Musings; Reviewing The NEW European Weeklies…

Average temperatures through the 1st (5) days of the month include highs of 46 F and a low of 29 F at Indianapolis. Instead, a frigid pattern will grip the region as we move through early March, including highs that will likely only top out in the lower to middle 20s and lows in the upper single digits to lower 10s as we move through the first week of the month (coldest centered on Sunday through next Wednesday).

Should we get any sort of snow down during the period (still up for debate as of this evening), lows will likely approach 0 F. The best opportunity for accumulating snow over the upcoming week would come Friday night into Saturday, but confidence remains low. Thereafter, we prefer the “suppressed” ideas currently portrayed by modeling as more meaningful winter storm threats impact the lower Ohio/ TN Valley and southern Appalachian region- especially with such an anomalously cold pattern in place.

Speaking of cold, the deep and expansive snowpack across the central and northern Plains won’t allow the late season taste from the arctic to modify as much as it may otherwise. As the frigid air mass settles southeast, below zero wind chill values are a good bet early next week across the northern half of the state. “Tap the breaks” on meteorological winter kicking off March 1st…

With that said, the NAO and AO are expected to remain positive and while initially “trumped” by the significantly negative EPO, this will trend positive by mid-month. These all suggest the cold is limited and that there shouldn’t be any change to the idea that we really begin to feel more spring-like by the middle of March. This is backed up by the continued idea that the MJO rumbles into Phase 4 by mid-March, as well (again argues for warmth).

Sure enough, longer range models show the ridging and associated warmer times ahead:

It should be noted that with the mean trough position taking up shop across the western portion of the country mid-March, not only should we moderate, but we should also see a return of wetter/ stormier times. With the GOM (Gulf of Mexico) running above normal, early season severe weather outbreaks will have to be closely monitored…

The new European Weeklies in this evening also back up the idea of an unseasonably cold 1st half of the month giving way to milder conditions by mid month. The model paints a drier than normal pattern over the Ohio Valley and Mid West over the next couple of weeks before wetter signals return by the middle of March.

Permanent link to this article: https://indywx.com/2019/02/25/frigid-open-to-march-and-late-month-musings-reviewing-the-new-european-weeklies/

All-Access Video: Does Another High Wind Event Loom This Weekend?

The potential of another high wind event this weekend is on the table and we look ahead to a much colder than average open to March…

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Permanent link to this article: https://indywx.com/2019/02/25/all-access-video-does-another-high-wind-event-loom-this-weekend/

Potential Wintry Mischief Through Early March? Late Month Changes…

Top wind gusts today have reached 66 MPH at IND with numerous reports of downed trees and power lines throughout the northern half of Indiana.

As we look ahead through the upcoming week, a couple of rather minor systems may deal light precipitation to the area, but it’s what lies ahead next weekend that’s already drawing interest. Unfortunately, modeling is trying it’s best for a “repeat” high wind event next Saturday.

The overall setup is eerily similar as a rapidly strengthening surface low tracks northeast into the Great Lakes region. This setup would once again support 50+ MPH gusts.

With the pattern change underway at this point, colder air will be more readily available and backside snow may be more “meaningful” next weekend. That’s something we’ll be keeping a close eye on.

Winter weather enthusiasts will have a couple of weeks of at least being on the playing field for the possibility of late season accumulating snow, but it continues to look like that window closes quickly by mid-March as a true spring pattern takes hold.

A much colder than average pattern can be expected through the first half of March, including the potential of a couple opportunities for late season accumulating snow.
Once to mid-March, eastern ridging is expected to take hold of the pattern and result in a much warmer 2nd half of the month.

For those who watch the operational data with each and every update (sometimes as much as 4 times per day)- tread with caution. While significant late season winter storms can result from such a pattern change that’s underway, it’s impossible to worry about specifics in this type of regime until within 4-6 days.

It would appear the pattern would support potential “fun and games” next Saturday, the 2nd, and possibly again in the March 5th-6th time frame.

Enjoy it while you have it, lovers of winter… Signals continue to point towards a significant shift to warmer times for the 2nd half of March.

Permanent link to this article: https://indywx.com/2019/02/24/potential-wintry-mischief-through-early-march-late-month-changes/

Sunday Morning Video: Repeat Next Weekend?

Is another damaging wind event on the horizon next weekend?

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Permanent link to this article: https://indywx.com/2019/02/24/sunday-morning-video-repeat-next-weekend/

All-Access Long Range Update: Walking Through March…

Recently, a “transient” pattern has dominated. This has kept any sort of long-lasting cold at bay and resulted in above normal precipitation. As we get set to close out February and welcome in a new month, a pattern change is on the horizon.

This overall shift in the pattern will drive a more sustained and significantly colder than normal regime southeast. In short, cold is set to “overwhelm” the pattern through the first couple of weeks of March. In the most extreme case (especially if we can get snow down), we will be able to challenge records at some point during the 1st (10) days of the month.

In spite of a neutral to positive AO and NAO, a significantly negative EPO and MJO rumbling through the cold late Feb and early March phases look to trump the otherwise warm signals. We also can’t forget about the significant SOI crash. Let’s dig into some of the latest data:

CFSv2


Note the modeling spreading the cold out during the Weeks 2-3 time period before gradually modifying things as we move into the middle and latter portion of March. The mean storm track shifts to the east during the first couple of weeks of the month (pattern will likely be dominated by more snow vs. rain events during this time period) before wetter than normal conditions return for the 2nd half of the month.

JMA Weeklies

Week 1
Week 2
Weeks 3-4

Like the CFSv2, the model overwhelms the pattern with cold during the Week 2 time period. Also similar to the CFSv2, the JMA Weeklies bring ridging back into the East and associated warmth by mid-month. While we haven’t included the precipitation anomalies in this post, the model does bring wetter than normal conditions back into the area by mid-March.

European Weeklies

The NEW European Weeklies remain consistent from Monday’s update (and data above) in delivering a very cold 1st half of March. The core of the cold looks to be centered over the upper Midwest and Northern Plains, but temperatures for the balance of the first couple weeks of the month will likely resemble what we’d expect in late January or early February vs. March. While precipitation will likely run below normal (thanks to the cold pattern), the model deliver above normal snowfall during the period. As we move into the 2nd half of the month, warmer (and wetter) conditions are shown to return.

Given all of the above, we expect the primary upper air pattern to feature a central and eastern trough through the 1st half of March before that trough settles into the West during the 2nd half of the month. This will open up the eastern portion of the country for not only warmer air, but a return of moisture-laden storm systems and the potential of strong-severe storms at times.

Permanent link to this article: https://indywx.com/2019/02/21/all-access-long-range-update-walking-through-march/

It Was A Case Of Delayed, But Not Denied…

While arriving later than originally expected (recall we originally thought the cold, wintry pattern would start on the 18th), it sure appears as if this was a case of “delayed, but not denied.”

The latest GFS and European ensembles are keying in on a significant pattern change as we put a wrap on February and open March. (Looks like we were about a week early in jumping on the cold bandwagon).

First and foremost, there’s excellent overall agreement amongst data (increases confidence significantly during the medium to long range period).

Days 1-5: Southeast ridge continues to dominate during the short-term period and there’s no high-latitude blocking to speak of. This suggests storms will continue to “cut” northwest of the region and place central Indiana in the “warm” sector, with transient, backlash cold/ snow potential.

Days 6-10: Significant changes begin to take place as heights (ridging) builds across AK. This is important as it can help “dislodge” late season cold air (and send it southeast). The SE ridge is also in the process of getting squashed during this period. We’ll likely transition away from the moisture-laden storm systems and replace with faster, overall weaker, systems that will be more capable of producing wintry precipitation.

Days 12-16: A total transformation of the pattern has taken shape since the Day 1-5 period. The new ‘mean’ trough position takes up shop across the East with the AK ridge continuing to dislocate late season arctic air southeast. The GEFS also shows a reflection of a southwest ridge which can be helpful in the overall storm track that could potentially deliver more “meaningful” wintry systems across the OH and TN Valleys as we get into the first couple weeks of meteorological spring.

Side notes: We’ve reviewed the crashing SOI index and this increases our confidence in a much colder pattern developing (typically takes place around 10-12 days after the crash begins). We’ve noted the deeply negative values against the base state which would suggest the cold pattern should continue for some time. We still believe the pattern remains colder than average, overall, through the 1st half of March.

The latest deeply negative EPO adds fuel to the fire in the idea of a cold open to March.

Given this, there should be no surprise to see the cold anomalies showing up on the latest medium-long range ensemble guidance:

It sure appears March will come in like a lion; will it go out like a lamb?

Permanent link to this article: https://indywx.com/2019/02/20/it-was-a-case-of-delayed-but-not-denied/

Long Range: Cold Pattern Isn’t Going Anywhere Fast…

We’ll save our short-term discussions for the severe and high-impact arctic outbreak on deck and focus our attention in this post to the upcoming several weeks. In short, we don’t expect the cold pattern to break anytime soon. Could there be a day or two of “relaxation?” Yes, but from an overall perspective, confidence is higher than normal on the colder than average pattern continuing through the month of February.

Let’s dig in to the teleconnections:

EPO

AO

NAO

PNA


Given the teleconnections in agreement pointing towards a cold pattern, it shouldn’t come as a surprise that the majority of data is also on the cold train as we flip the page into February:

CFSv2 Weeklies

Weeks 1 & 2

Weeks 3 & 4

JMA Weekly

GEFS

While we aren’t licensed to show the European Weeklies, the new update runs with a cold pattern into early March. This falls in line with the overall consensus of longer range data, backed up by teleconnections.

Though not nearly at the amplitude of a few weeks ago, the MJO (Madden-Julian Oscillation) is forecast to move through Phases 5 and 6 in the coming weeks before going back into the “null” phase.


Phases 5 and 6 this time of year would suggest colder anomalies are more likely around our neck of the woods:

Given the above, we continue to think a colder than average “2nd half” of winter looms for the region. We lean heavily on the NAO, EPO, and AO state(s) this time of year and all would point towards a cold time of things moving forward, overall. The latest European Weeklies are interesting from a couple of fronts- initially very cold and then progressively stormy. The idea here is that we remain quite wintry through February and into early March before this pattern breaks. While we may not see a “repeat” visit of the Vortex, it wouldn’t surprise us to see another major arctic outbreak again this winter (after next week), but that likely comes later, and towards the end of the game before we snap into spring.

Buckle up; we think we have a long way to go this winter…

Permanent link to this article: https://indywx.com/2019/01/24/long-range-cold-pattern-isnt-going-anywhere-fast/

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