Category: MJO

Feb 24

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/

Feb 21

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/

Feb 19

Evening Video Update: Snow, Storms, And A Major Pattern Shift On The Horizon…

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Permanent link to this article: https://indywx.com/2019/02/19/evening-video-update-snow-storms-and-a-major-pattern-shift-on-the-horizon/

Feb 17

Sunday Morning Video Update…

A wintry mix this morning sets the stage for another active week of weather across central Indiana. We also look forward to late Feb and early March…

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Permanent link to this article: https://indywx.com/2019/02/17/sunday-morning-video-update-3/

Feb 16

All-Access Saturday Evening Video Update…

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Permanent link to this article: https://indywx.com/2019/02/16/all-access-saturday-evening-video-update/

Feb 14

Reviewing The Latest European Weeklies And Updated Long Range Thoughts…

We’re growing closer and closer towards the period we’ve been thinking would present one last round of cold, wintry weather (relative to normal) for the ’18-’19 season.

While the stormy idea will likely end up being correct, the significant cold that we thought would “spread out” (as opposed to being confined to the NW and northern Plains) is in jeopardy.

The overall upper air pattern over the upcoming few weeks will likely continue to be dominated by a mean trough position across the central and west, along with the persistent southeast ridge.

This will continue to result in above normal precipitation into the first week to 10 days of March, with a very active storm track.

From a temperature perspective, the baseline of our ideas being centered on the MJO appears to be the error in our forecast. It’s not that the MJO isn’t heading into Phase 8 (it’s officially there now, as noted below), but it appears other teleconnections are “trumping” this cold ingredient.

The combination of the positive Arctic Oscillation (AO) and negative Pacific North America pattern (PNA) are the drivers and are showing no signs of wanting to let go of the wheel.

The AO is forecast to remain strongly positive into early March.

The PNA is forecast to remain negative into early March.

Note how both of the above support that southeast ridge and associated relative warmth.

At one time, it appeared as if the North Atlantic Oscillation (NAO) would dip negative, however, that’s no longer the case.

While the active idea will come to fruition, the cold (at least to the magnitude we thought) will have a difficult time. That isn’t to say that enough cold air won’t get involved with a couple of these storms to result in wintry precipitation of significance, but rather that sustained cold will be tough to come by. Snowfall (of the heavy, wet variety) very well still could end up above normal with these moisture-laden systems over the next few weeks.

European Weekly Update

The new European Weeklies are in and follow the idea above nicely. They forecast a very stormy pattern to persist over the next few weeks with a battle ground between cold to our northwest and warmth to our southeast. We’ll have to be watchful for a couple of storm systems capable of delivering heavy amounts of precipitation. Given the teleconnection states over the next 6 weeks, it continues to look like any sort of significant wintry weather will need to take place before mid-March. Thereafter, warmer than normal times are expected, including true spring-like weather emerging. I know most can’t wait…


Permanent link to this article: https://indywx.com/2019/02/14/reviewing-the-latest-european-weeklies-and-updated-long-range-thoughts/

Feb 12

We Have The Storms; Time To Add The Cold…

Over the past month, a widespread portion of the Ohio Valley, including central Indiana, is running close to 200% of average in the precipitation department. There’s no wonder flooding issues have resulted in spots- especially across the lower OHV region.

As we look ahead, the active storm track will persist, but there will be one key missing ingredient from the better part of the past couple of weeks and that’s more in the way of sustained cold. After reviewing some of the latest data, there’s no reason to change our ongoing idea of the transitional period (in the midst of that now) giving way towards one that will feature more in the way of “lock and load” cold in that 2.18 through 3.10 time period. We expect this period will run well below average in the temperature department and above average in the snowfall category. Snow removal clients, we recommend gearing up for a busy time of things over the upcoming few weeks.

The basis of this idea initially focused squarely on the MJO and the fact that modeling was keying in on things swinging into the favorable cold phases of 8, 1, and 2.

Taken at face value, this would be the corresponding upper air look in those respective phases:

Phase 8 (coldest)

Phase 1

Phase 2

Phase 3 (cold begins to “back into the west and there’s at least a hint of the SE ridge returning)

As most longtime followers know, we put more stock into the NAO state during the latter winter and spring months, as this teleconnection can “trump” others during this time frame. We notice the NAO is forecast to trend negative as we progress through the back half of February.

A negative NAO will result in widespread cold this time of year:

After remaining strongly positive for the past couple of weeks, the AO is forecast to plunge negative as we progress through the remainder of February. Again, this increases confidence on a return of more sustained and significant cold potential.

It should also be pointed out that the active pattern should continue, especially considering the southeast ridge should put up some resistance over the upcoming couple of weeks. The latest ensemble products would agree in the mean upper air pattern:

With colder air overwhelming the pattern, more of these storms will be capable of producing impactful wintry precipitation over the upcoming few weeks. After storms grab the headline, attention will shift to the possibility of another significant arctic blast before the end of the month.

In the more immediate term, we continue to keep close tabs on the following dates for the potential of snow and/ or ice:

I. Friday night, 2/15 and Saturday, 2/16- southern half of Indiana

II. Sunday, 2/17

III. Tuesday night, 2/19 and Wednesday, 2/20

Permanent link to this article: https://indywx.com/2019/02/12/we-have-the-storms-time-to-add-the-cold/

Feb 10

All-Access Sunday Evening Video Update…

Another busy weather week is dialed up for central Indiana, including flooding and accumulating snow. We also look ahead to late month and early March…

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Permanent link to this article: https://indywx.com/2019/02/10/all-access-sunday-evening-video-update/

Feb 10

Transition Period Set To Give Way To A Big Finish To Winter?

We don’t see any reason to alter our thinking of how the upcoming (4) weeks plays out:

This week features a transitional pattern back to a predominantly colder and snowier than average period from 2/18 through 3/10.

The MJO continues to have Phase 8 on its mind.

To no surprise, the GEFS is going right to what a Phase 8 should yield:

Days 1-5

Days 6-10

Days 10-14

With widespread cold set to once again overwhelm the pattern, the active storm track will begin to take on an increasingly snowy theme in the aforementioned period. This is a type pattern that may once again challenge cold records somewhere in the late February or early March time frame. While likely not to the magnitude of the bitter blast a couple weeks ago, it wouldn’t surprise us in the least to head back to record daily cold territory before pulling out of this pattern and heading on towards spring.

Permanent link to this article: https://indywx.com/2019/02/10/transition-period-set-to-give-way-to-a-big-finish-to-winter/

Feb 09

Saturday Morning All-Access Video Update…

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Permanent link to this article: https://indywx.com/2019/02/09/saturday-morning-all-access-video-update/

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