Category: Weather Rambles

Jan 07

Dinnertime Rambles: Stage Set For The Next Couple Weeks…

The storm system that will impact the region late this week will really be a precursor of what lies ahead over the upcoming 10-14 days.

Here’s how we envision the ‘mean’ pattern shaping up through the January 20th time period:

This pattern is driven by Phase 5 of the Madden Julian Oscillation (MJO) and, secondarily, by a positive EPO.

Upper air patterns in January typically look like this during MJO Phase 5:

The analog composite above isn’t as strong compared to reality with the northern Plains/ Rockies cold and that’s where things could potentially turn a bit more interesting, locally, once out of Phase 5 (more on this a bit later in the week). As it is, this cold will try to press and as this takes place, resistance from the East Coast ridge will put up a fight. The battle ground will set-up over our neck of the woods and the end result will be an active/ stormy pattern that features “transitional” cold shots. This time of year, even warmest of patterns can present wintry challenges, however. Case in point is this weekend. Personally, I think what will actually take place with respect to the strength and track of the low pressure system will end up being a blend of the intense European and more progressive GFS. It’s going to be mighty tough to drive such an intense low so far northwest, per the Euro- especially considering the placement/ strength of the high to the north.

With that said, this continues to place northern parts of the state under the threat of a wintry mix of snow and freezing rain/ sleet, while central and southern areas deal with flooding rain. If traveling the state Saturday, expect a significant temperature gradient that will result in a difference of as much as 20° within 10 miles in some cases, especially across north-central parts of the state. I think there’s still the chance rain could end as wet snow across central Indiana Saturday PM, but the better chances of accumulating wintry precipitation will likely be to our north.

Locally, the bigger concern at this point has to do with the potential of 2.5″ to 3.5″ of rain with locally heavier amounts. The bulk of this likely falls late Friday night into Saturday morning. Localized flooding is possible and we’ll likely have to begin issuing storm briefs this time tomorrow.

Next up will come storm threats in the 1/14 and 1/16-1/17 time frame…

Stay tuned, friends.

Permanent link to this article: https://indywx.com/dinnertime-rambles-stage-set-for-the-next-couple-weeks/

Jan 02

Fresh Short-Term Update; Longer Range Rambles…

Dry air continues to “eat away” at the advancement of precipitation northward this afternoon. It now appears as if we’ll escape rain-free through the evening hours, with steadier rain lifting north into central Indiana towards 10p to 11p.

Heaviest totals still look like they’ll fall across southeastern Indiana (amounts up to 1″ possible) with lighter amounts of .20″ to .40″ across the more immediate area.

Most of the daytime Friday will feature a lack of significant rain, but there could be some drizzle and spotty light shower activity around at times.

It’s as we get into Saturday morning that we need to monitor the track of vigorous upper level energy moving southeast out of the northern Plains and into the lower Ohio Valley. In response to this, an expanding area of snow and/ or mixed precipitation should initially develop across Iowa before building into Indiana prior to sunrise. These systems are admittedly tricky and can spawn surprises and we’ll keep close eyes on things over the next 24-36 hours. As things stand now, I would place the best chances of accumulating snow from Iowa, northern IL, northern IN, and into northern OH with this system, but please stay tuned.

The next weather maker, locally, will likely be responsible for another opportunity of snow Tuesday into Wednesday.

In a way it’s ironic we’re looking at back-to-back opportunities of sticking snow in what’s a warmer than average pattern. This, of course, is on the heels of December’s above average snowfall month. Central Indiana snowlovers know all too well that frigid patterns can be bone dry around these parts…

Longer range hinges squarely on the shoulders of the MJO. Things are highly amplified and will result in one of two scenarios- swinging out of the warm phases and into the traditionally cold phases for mid-winter after mid-month, or circle back through Phase 5. If it’s the latter, anomalous warmth would continue across the east while significant cold takes up shop across the west. In January, Phase 5 is the last thing eastern fans of winter want to see.

As it is, I continue to believe the favorable northeast Pacific will have the final say on this winter with a more favorable regime developing during the 2nd half of January that would pull the cold into the region in more sustained fashion (next 10-14 days will feature transitional cold along with the stormy pattern).

The latest European Weeklies may be starting to see this as the relative warmth in Week 2 gives way to colder times Week 3.

MJO Phase 5 is set to dominate the Week 2 timeframe.
New Weeks 3-4 shows a colder pattern developing.

A very active pattern is set to remain intact over the next 2-3 weeks and even in the warm patterns, snow and wintry mix events can prove to be a headache this time of year.

Both the GEFS and EPS show the EPO moving from a strongly positive phase now (also argues for the warmer than overall pattern in the immediate-medium term) towards neutral to negative after mid-month. We’ve been noticing the tendency both models have had trying to drive the negative EPO too quickly (recall only a few days ago the models wanted to develop the negative EPO around the 12th or 13th).

Rest assured, our eyes will be glued to the MJO and EPO through the 2nd half of the month. Time will tell if the highly anticipated favorable warm northeast Pacific SSTs will begin to do the trick…

Permanent link to this article: https://indywx.com/fresh-short-term-update-longer-range-rambles/

Dec 30

Important To Know What Lever To Pull And When…

As another year comes to a close and the winter pattern begins to “mature,” we thought we’d do a little rambling…

This evening’s rambles have to do with the variety of “drivers” that at times like to take control of our weather pattern. You hear us use terms like the MJO, EPO, AO, PNA, and NAO (amongst others) often, but at times, these various pattern drivers can have more impact than others, and at varied times of the year.

Traditionally, if the MJO (Madden Julian Oscillation) is highly amplified, that’s going to serve as the basis of our medium or longer range forecasts. However, if the MJO is in the null phase, other teleconnections can take control of the wheel. Sea-surface temperature configuration can give hints to the way these elements may behave during the season(s) ahead, but we caution each respective season takes on a flavor unique to it’s own. That’s what makes this business so fun, challenging, and, at times, frustrating. 🙂

It’s also important to understand when the ingredients noted above have the greatest impact on our immediate weather. We love to lean more heavily towards the NAO and AO mid-to-late winter into the spring, for instance. Case in point, a negative EPO and positive PNA can quickly trump a positive AO/ NAO this time of year, and vice-versa.

In the event you didn’t have a chance to see it Sunday, we released our January Outlook. We have a very stormy month outlined that includes cold “overwhelming” things as the month progresses. A lot of this has to do with the fact we think we see a “shake-up” with the MJO out of the warm phases and into the traditional cold phases of 8,1, and 2 taking shape during the 2nd half of the month. Additionally, we continue to believe the favorable north Pacific sea surface temperature configuration (for a cold Great Lakes and OHV) will begin to force the negative EPO/ positive PNA.

The NEW European Weeklies show the transitional time of things through the 1st half of the month, but note the building more persistent NW NA ridge during the 2nd half of the month and corresponding reflection of an eastern trough. Should the MJO be heading into Phase 8 around this time frame (and we think it will), this trough will likely correct stronger in future updates for late month.

The model sees the stormy time of things through the month and into February. (Important to note that even “warm” months this time of year can also feature above normal snow. Just see this December- nearly an inch above normal for the month). As things stand now, we see multiple opportunities for snow as January gets underway, including Saturday PM, and again Tuesday night into Wednesday.

Make it a great evening! We’ll be back early in the morning with a fresh video update.

Permanent link to this article: https://indywx.com/important-to-know-what-lever-to-pull-and-when/

Dec 12

Latest Thoughts On Early Next Week; Long Range Update Into Early Jan…

Through the 11th, December is running 1.6° above normal in Indianapolis. This milder than normal theme is rather widespread so far this month through the Lower 48.

As we look ahead, there are continued reasons to believe the pattern will begin to go through more of a transition towards an ultimately more sustained cold pattern as January evolves. We think that transition really started early this week and will feature plenty of “back and forth” over the the next 2-3 weeks before settling into the more sustained cold regime. There will be storms and “rumors of storms” that we’ll have to track through the transitional period, including smack-dab in the heart of the holiday season this year.

The latest JMA Weeklies (update each Thursday morning) shows this “fight” over the next 1-3 weeks.

JMA Weeklies Day 3-9 shows the cold returning to our portion of the country.
The pattern warms significantly across the Plains in the 10-16 day time frame and some of this milder air will try and eject east into the Ohio Valley.

Without blocking in place, the way the JMA Weeklies handle the pattern is likely, but the Weeks 2-3 time period does have a chance to offer up a headache or two as the models may begin to adjust to an increasingly “blocky” time of things.

There are at least “hints” that some of the teleconnections that would promote more of a blocky pattern are beginning to align. We caution though that this does take time for these feature to mature and begin to ultimately have a greater impact on our pattern.

The latest GEFS insists on a developing negative EPO in the medium to longer range. We know this favors eastern cold. Eventually, this should, indeed, take place, especially due to the northeast Pacific SST configuration and help drive more long-lasting cold, locally.
Interestingly, the GEFS also depicts a developing negative NAO mid and late December. This can help result in more sustained cold across our portion of the country into the northeast.

As we revisit the latest SST configuration, there’s continued reason to be very excited about this winter if you’re a fan of colder and snowier than normal conditions. We always knew December would be the tough month before the pattern settles into the mean winter pattern late December into March. Now, time to just sit back and watch things unfold. 🙂

Now, back to the short-term. Despite forecast models very much still in (2) separate worlds, we’ve dug into analogs and looked through countless similar patterns from the past. As model consensus develops (hopefully sooner rather than later), let’s see if they (speaking specifically to the GFS and European) converge on this similar solution for best chances of accumulating snow:

We still have many details to sort through and we caution that this system is far from being etched in stone. You’ll want to keep close tabs on latest developments over the next couple of days. With that said, we’re looking for potential wintry impacts here across central Indiana beginning Sunday night and continuing through Monday.

This evening’s video update will focus solely on the Sunday-Monday system, including the latest model developments from 12z. Have a great Thursday!

Permanent link to this article: https://indywx.com/latest-thoughts-on-early-next-week-long-range-update-into-early-jan/

Nov 23

VIDEO: Thanksgiving Week Keeps Us Busy…

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Permanent link to this article: https://indywx.com/video-thanksgiving-week-keeps-us-busy/