Dec 07
It’s not that there isn’t any cold to speak of, but instead the lack of sustained chill moving ahead. This morning, we discuss why we believe that is with the…
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Permanent link to this article: https://indywx.com/2020/12/07/video-not-that-there-isnt-chill-available-but-sustainability-is-severely-lacking-we-explain-why/
Oct 18
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Permanent link to this article: https://indywx.com/2020/10/18/video-heavy-rain-overspreads-south-central-indiana-tonight-unsettled-week-ahead/
Sep 13
IND is now running more than 1.2″ below normal for the month and this is coming off a dry finish to August.
Note the localized, but significant, area of bone dry conditions extending east from eastern IL across central Indiana (while surrounding areas have cashed in on significant rains over the past 30 days):
The upcoming 7-days won’t offer up much relief from the dry conditions as high pressure dominates. Even the mid-to-late week cold front should pass through the region mostly dry.
Most guidance only drops between a trace and 0.10″ of rain on central Indiana over the next (10) days as the dry pattern rolls along. The GFS and European ensemble products highlight the dry regime well:
Ironically, the overall pattern should shift in dramatic fashion as autumn matures and heads into winter. We still expect an about face late autumn as the wet anomalies paint themselves across our region as the southeast turns dry, thanks to the La Nina pattern…
Permanent link to this article: https://indywx.com/2020/09/13/extended-dry-period/
Aug 30
Well here we are on the eve of meteorological fall and, right on cue, there’s a change on the horizon in the overall weather pattern. Does the quick start to a more autumn-like feel early and mid September continue into late month, or for that matter October and November? Let’s look at September first:
I. MJO will remain active- moving out of Phase 2 and into 3, 4, 5, and 6.
II. Tropics should remain busy with more of an East Coast threat.
III. West looks to remain hot and dry.
Note the precipitation and temperature patterns associated with the MJO phases this time of year:
The next couple of weeks will feature multiple cold fronts sliding through the region and each will provide progressively cooler air. The front coming through around Labor Day may even result in the hoodies having to be pulled out for the first time, including an early October-like feel. BUT- note how the MJO wants to rumble into Phases 5-6 towards late month. These will likely lead to a warmer pattern around Sept. 20th (give or take a day or two) through the remainder of the month.
As we broaden the spectrum a bit and focus on September through November, let’s start by taking a look at how the oceans may impact the pattern:
Most models suggest La Nina will peak late fall or early winter before giving way to La Nada by spring.
Aside from the upwelling associated with Laura, most of the Gulf of Mexico and certainly off the East Coast remains much warmer than normal. Unfortunately, this, along with other favorable conditions in the main development region (MDR) will likely continue to promote a hyperactive 2nd half of the tropical season. The other impact will likely be a warmer than normal fall season along the eastern seaboard, bleeding back into areas west of the Appalachians. Furthermore, we think the MJO will lean more towards Phases 6-8 for mid and late autumn.
The blend of the CFSv2 and European seasonal data sees a similar forecast to what we have out for September for the autumn, as a whole:
We believe fall 2020 will run slightly warmer than normal for our immediate region with the greatest spot for cooler anomalies to show up throughout the central Plains. After what we believe will be a wet September, things may take a turn for the drier in October before flipping back to wet in November. We prefer the way the CFSv2 handles the precipitation pattern compared to the European.
Next seasonal outlook we produce? Our annual winter package. Tick tock…
Permanent link to this article: https://indywx.com/2020/08/30/september-2020-and-fall-outlook/
Aug 09
While we still have a few weeks left of meteorological summer, we’re hard at work finalizing our fall outlook and prep continues for winter. By the way, our fall outlook will be online Friday morning, the 28th.
From this distance, there’s obviously a risk involved with seasonal data that we’re reviewing and tweaks (particularly to the initial winter idea) will undoubtedly have to be made. In short, we anticipate a weak La Niña to dominate the fall and winter, with a robust MJO.
Of course, it’s important to remember, no La Niña is like the other and a simple “broad brush” approach never works.
Without question, the tropics will claim headlines through the fall. Unfortunately, like others, we anticipate a significant uptick in activity late August into October. A few major hurricanes are likely, as well. The Gulf of Mexico and Carolina coast appears particularly vulnerable…
Most computer model data is leaning towards a warm autumn. We’d agree, overall, but leaning wetter than the majority of data right now, due in large part to tropical impacts.
The coolest of the seasonal data is the CFSv2. It’s easy to interpret a cooler Central and East if the ridge and associated heat is so strong across the West. We will keep close tabs on trends over the next few weeks. Nina falls are notorious for at least a few weeks early on of unseasonably cool weather as well. Stay tuned.
As for winter, from this distance we’re bullish on a wetter, warmer than normal season, locally. Below normal snowfall is expected as of now. A dominant southeast ridge is expected to carry the day, at times flexing north into the TN and Ohio Valley.
Interesting, like fall, the CFSv2 is the “coolest” of the big 3 seasonal models. Again, we’ll continue to keep close eyes on trends. Given performance of recent winters past, you may say I’ll just go with the opposite of what these seasonal models say. You’d have good reason for doing so. Unfortunately, that southeast ridge almost seems like a lock though. It’s also becoming more difficult to ignore the trends over the past decade or two.
Much more later on both fall and winter! Enjoy your Sunday!
Permanent link to this article: https://indywx.com/2020/08/09/thoughts-begin-to-shift-to-fall-and-winter/
Sep 23
I want to give a couple examples of significant conflicting signals- both short and long-term. The end result is a situation where long range, climate, and seasonal models are likely to have a very tough time not only in the medium to long range (2-4 week period), but thinking seasonally, as well (winter and next spring).
Short-term
To start, let’s look at the EPO. While strongly positive at present, both the EPS and GEFS pictured below take the EPO, or East Pacific Oscillation, negative in the coming couple of weeks.
A negative EPO pattern favors a trough across the eastern portion of the country, especially here in our neck of the woods, with western ridging.
All well and good, right? WRONG. The MJO, or Madden Julian Oscillation, is forecast to stall out into early October in Phase 1.
This time of year, Phase 1 argues strongly for eastern ridging and well above normal warmth while the western portion of the country can experience early wintry conditions.
Talk about contradiction! That’s what makes weather so fun and fascinating. Expect to be humbled often and to always learn! At various times of the year, select teleconnections can mean a lot more than other times of the year. For example, during the summer and fall, we lean heavily on the EPO, PNA, and MJO (if amplified). During the winter and spring, it’s important to take into account what the AO and NAO have to say. It’s important to know when to “pick and choose” when to use particular teleconnections… Furthermore, the various MJO phases (1-8) mean drastically different things at different times of the year. While lovers of chilly fall conditions have grown to hate an amplified Phase 1, they have to love it come winter (shown below). Just look at that difference!
Before jumping ahead to another example of “contradicting signals,” we’re confident the amplified MJO Phase 1 will carry the day through the short to medium range period. Note the strong agreement between the EPS and GEFS below with respect to temperature anomalies in the 6-10 day period.
With that said, there will be challenges within (the big difference as early as this weekend between the GFS and European operational data). A lot of that has to do with the “fight” between the EPO and MJO to take control.
As all of this unfolds across the East, the west will begin to cash in on early winter. Well below average cold and snowy conditions will begin to make headlines over the weekend into next week across not only the Rockies, but some of the low ground, as well. Should the MJO swing into Phase 2 (and I think it will towards mid-Oct), then watch out. We’ll be looking at a rather significant shift towards a much colder feel- and it’ll sting even more so with the late season heat over the better part of the next couple of weeks.
Flipping the page to winter (remember, our prelim. winter outlook will be posted later this week) and the contradiction continues. Upon looking at the current SST configuration, one could easily argue we’re talking about a La Nina winter unfolding ahead.
Meanwhile, the current SOI would suggest we’re in a moderate El Nino.
If you think this can’t wreck havoc even on the short-term forecast pattern, think again…
To close, while the conflicting data can create headaches at times, it’s more fascinating than ever trying to sift through the data and build our forecast(s). It’d be wise to expect more wild swings ahead- leave it to us to try and minimize the impacts of those swings in your day-to-day personal and professional lives. Accordingly, it’s also ultra-important to factor in additional items, such as solar and PDO into the equation for the upcoming winter.
Speaking of, without giving too much away, if I’m a winter weather fan (and I am), I wouldn’t worry in the least about the current warmth… 😉
Permanent link to this article: https://indywx.com/2019/09/23/something-doesnt-jive/
Jan 04
Daily, we’re receiving questions around if and when winter will show up. While admittedly later than originally thought here, we’ve never been in the camp of “throwing the towel” in on winter. Our winter outlook that includes below normal cold and near average snowfall remains unchanged.
Before we get into some of our reasons why we think winter will show up (and likely make up for lost time), the upcoming week will remain much warmer than average.
We’re tracking (3) storm systems that will deal the region rain over the upcoming week:
As a whole, rainfall amounts won’t be particularly impressive for most, with 7-day totals between 0.25″ to 0.75″ for central portions of the state. Heavier amounts can be expected across southern areas.
Now, let’s look ahead to some potentially colder times. Before moving forward, it’s important that we recognize models have attempted once already to drive in a wholesale pattern change to colder (originally thought to be underway now). Perhaps it’s a case of “delayed, but not denied.” There’s a lot going on behind the scenes:
There are significant changes brewing in the arctic/ higher latitudes that have to raise an eyebrow at the very least.
Today
Mid-January
Note the higher pressures building over the upcoming 10-14 days in the arctic regions.
Not surprisingly, the models begin to tank the AO.
The PNA rises…
Something that also lends credence to a potential pattern shift is the recent SOI drop.
This would tend to suggest that an active storm track may be in place as the more bonafide cold shift is underway.
The moral of the story? Despite the milder period being extended a couple weeks longer than originally thought, there’s still a lot on the table this winter. It’s far too early to think winter’s over before it’s really even begun for most. We expect to see increasingly wintry conditions show up around the middle of January…
Stay tuned.
Permanent link to this article: https://indywx.com/2019/01/04/trying-to-answer-questions-when-winter-will-show-up/
Nov 10
Before we get into the updated thinking on the pattern, lets review what we have out:
The first week of November has featured an incredibly warm start to the month. (Image courtesy of MRCC).
Speaking of warmth, 2016 has been a very warm year.
(The cold of 2014 seems so long ago…)
Back to present. We’ve targeted the middle part of November to finally beginning “bucking” the recent warm trend. This won’t happen overnight and will be a battle of back and forth, initially. Thus, the “step-down” label. To be clear, November, as a whole, will finish much warmer than average. It’s virtually impossible to counter the incredibly warm start. That said, we do anticipate “jabs” of colder air working in here over the next couple weeks. For instance, this weekend will feature lows in the 20s for most and highs not making it out of the 40s Saturday afternoon. (The average low and high at IND Saturday are 37 and 54).
Despite being in a weak La Nina, the pattern is taking a while to respond. Remember, we’re coming off one of the strongest El Ninos on record. Until we slow the PAC jet, significant, long-lasting, changes won’t occur. We can lean on the AAM (Atmospheric Angular Momentum) forecast for clues as to when this may occur. You can read more about the AAM here. My fellow local weather compadres, Michael Clark, Ed Valley, and Kirk Hinz have also written/ blogged extensively about the AAM and resulting impacts.
When we look at the AAM forecast (above), we note the westerlies may begin to slow (indicative of the negative values) in the 8-10 day period. This is crucial and, simply put, has to happen for the pattern to begin shifting into more of a position to allow sustained cold to enter the equation. We want to reiterate that this, in and of itself, doesn’t create the cold, but instead allows the pattern to begin shifting away from the Nino-like (warm) regime into more of a La Nina pattern, as a whole. – Hey, you have to start somewhere.
If we can finally get the westerlies to slow, other elements are in play that could (and should) lead to a colder pattern as we move forward. Our (3) big teleconnections are in a position favorable for cold for mid/ late November, into early Dec.
Additionally, the EPO is forecast negative off the GEFS and EPS. (Images courtesy of Weatherbell.com).
Again, this is a cold signal. (Image courtesy of Madusweather.com).
The ensemble data is also beginning to key-in on higher heights (blocking) developing over the top. Notice the significant changes in the overall look to the pattern between now and days 11-16. (Images courtesy of Weatherbell.com).
In summary, and in the face of *most* seasonal data that is screaming warm, warm, warm, we still don’t have any significant changes to our overall thinking of “step-down” mid-November giving way to more sustained wintry-like conditions in the overall sense from the Thanksgiving-Christmas period. Time will tell and only the Good Lord knows what the future holds, but we’ve done far too much work and research to throw the “game plan” in the trash before the game even begins…
Permanent link to this article: https://indywx.com/2016/11/10/a-word-or-two-on-where-we-think-this-pattern-is-going/
Oct 02
We continue to finalize our winter forecast, which will be posted, as always, here later this month.
As little as only a few months ago, data suggested a major La Nina for the upcoming winter season. That data has since backed off significantly. In fact, some runs suggest we’re back into a weak-ish El Nino state by spring. At the very least, we are confident on avoiding a strong La Nina this winter and lean more in the direction of a weak Nina, at best, to neutral signal. The CFSv2 is interesting, as always, with the spread in region 3.4.
In addition to the central PAC anomalies, we also are keying in on some other items of interest in the overall SST configuration:
I. Warmth in the GOA (Gulf of Alaska)
Argues for central cold this winter, spreading east with time.
II. Warmth off the eastern seaboard
Will likely serve to limit the ability for the cold to spread east early on in the season
The SST CA model is quickly becoming one of our more trusted seasonal forecast models. We note how it becomes increasingly bullish on a central and eastern trough as winter wears on (by the way, this is likely to go deep into spring this year, too).
Cold overwhelms the pattern and when you combine it with the active storm track (noted by the green hues, suggesting above normal precipitation through our neck of the woods), confidence is continuing to grow for an above normal snow season.
The SST configuration on the JAMSTEC would suggest a cold, stormy set-up, locally. That said, while it sees the above average precipitation, it’s awfully warm at the surface.
The NMME (to no surprise…) would suggest a very warm, wet winter.
As a reminder, our complete and final annual winter outlook will be posted here during the second half of October. That will include additional model data, along with several other points behind our reasoning for our winter forecast. As we always do, we’ll put “pen to paper” when it comes to our winter forecast, including our expected temperature and snowfall anomalies. Given the data above, including the warm JAMSTEC and NMME, it’s going to be very, very hard to see a warm winter here. In fact, our idea is for the exact opposite, given the SST configuration, and lines up more closely with the SST CA idea at this point. We’re also in the camp of a very, very active storm track through the Ohio Valley. “Big-hitter” potential is present from a winter storm perspective, especially given that we are likely to see resistance from the SE ridge.
Much more later this month…
Permanent link to this article: https://indywx.com/2016/10/02/winter-ideas/
Apr 21
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Permanent link to this article: https://indywx.com/2016/04/21/fresh-summer-thoughts/