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Category: Winter thoughts…
Permanent link to this article: https://indywx.com/video-certainly-isnt-a-boring-pattern-to-close-november-and-open-december/
Oct 06
What Can We Learn From A Persistent Negative October AO For The Upcoming Winter?
October has opened on quite a chilly note across not only central Indiana, but a good chunk of the eastern half of the country. Officially, Indianapolis is running 8.4° below average, month-to-date.
While warming will occur in the upcoming 7-day period, there are already seeds being planted for the return of unseasonably chilly conditions after this transitional warmth.
The pattern will take on signs that you’d expect from a positive PNA and trending negative EPO. That will pull the chill back into the east and we may just may trend wetter during the mid and late month period, as a series of cold fronts sweep through the region (fingers crossed).
The purpose of this post is to focus on the predominantly negative Arctic Oscillation (or AO) and what, if anything, we can learn for the upcoming winter. Note the AO continues a negative look over the upcoming couple weeks (it’s been negative so far this month, as well).
The combination of the persistent negative AO so far this month, along with what’s forecasted over the coming few weeks, got us interested to see what kind of patterns occurred during the following winter (Dec. through Feb.). We went back and looked at all October with a negative AO of 1, or more, since 1960 and this is what the analogs produced:
There’s obviously a lot of other ingredients we’ll factor into our winter outlook this year (per usual), but this is another interesting case study in front of us, especially with so many climate models blow torching the upcoming winter.
Our complete annual winter outlook will be online Sunday, November 1st.
Permanent link to this article: https://indywx.com/what-can-we-learn-from-a-persistent-negative-october-ao-for-the-upcoming-winter/
Jan 21
Catching Up On A Tuesday Evening And Looking Ahead…
January is flying by! With only 10 days left in the month, Indianapolis is running a whopping 8.2° above normal along with more than 3″ above normal in the precipitation department (unfortunately for snow lovers, this excess moisture has fallen primarily as rain, as IND is running a deficit of 5.2″ in the snowfall department).
On a broader scale, here’s a look at the current month-to-date temperature anomalies for the Lower 48 as a whole:
As a refresher, our January forecast looked like this:
The baseline of this thinking had to do with the idea we had that the MJO would roll out of the warm phases (5 and 6) and strongly into the colder phases after mid-month. Secondly, the other driver was the thought that the current SST configuration in the north Pacific would “force” a negative EPO as the winter season matured.
While the MJO did, indeed, rumble out of the warmer phases just after mid-month, the EPO has not cooperated. Furthermore, instead of the MJO tracking into Phases 8, 1, and 2, it appears it wants to go into the “null” phase to figure out its ultimate destination for the 2nd half of winter (this will be key with Feb. and March). While this doesn’t necessarily support warmth, it doesn’t offer enough ammo to fight the warm signal from the strongly positive EPO.
Now that we’re beginning to turn the page to the 2nd half of winter, there are other items to begin paying closer attention to. In addition to the EPO and MJO, some of these features include the AO, NAO, and PNA. With that said, to drive more of a consistent colder than normal theme, we need to get the EPO at least into the neutral range as some of the other ingredients noted above transition into more favorable colder phases. With a strongly positive EPO, it’ll be tough to sustain well below average temperatures.
With all of that said, all hope is not lost for winter lovers. Climatology speaking, we’re in the coldest time of the year. Even in “marginally” cold patterns, or even “warm” patterns this time of year, wintry issues can create headaches. Secondly, it’s worth paying close attention to the MJO over the next couple of weeks as some of the data wants to take things out of the null phase and transition towards the traditionally colder phases of 8, 1, 2, and 3.
As it is, the next couple of weeks should present a fairly active storm track across the region. In the face of what should truly be a “torch” pattern, the saving grace (at least for fans of winter weather) has to do with the strong Hudson Bay ridge and tendency this kind of pattern has to force stormy times underneath. While far from a “slam dunk,” these kind of patterns can produce- even in the face of a strong positive EPO.
If you had to choose, would you rather have a bitterly cold and dry regime or seasonably mild with at least being on the playing field for wintry mischief over the next couple of weeks?
More in the AM, friends. Make it a relaxing evening! 🙂
Permanent link to this article: https://indywx.com/catching-up-on-a-tuesday-evening-and-looking-ahead/
Sep 26
VIDEO: Game Changing Week Ahead; From Summer To Fall…
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Sep 25
IndyWx.com Preliminary ’19-’20 Winter Outlook…
Where does the time go?! This will be the 10th consecutive year we’ve released a winter outlook as the IndyWx.com brand. Thankfully, most of those outlooks have been rather accurate! A few of you have been along for the ride from day 1 and your continued support means more than you realize!
Our official, finalized, winter outlook will be published just before Halloween. It’s our expectation that there won’t be many significant changes to what we present below, but fall storms and tropical activity can have big impacts on the sea surface temperature patterns and the impacts can be profound in the 2-4 month period that follows. That’s the primary reason we have never released an official outlook before mid-late October. With that said, let’s dig in to the drivers behind the upcoming winter:
I. Warm anomalies across the northeastern Pacific
II. Neutral ENSO
III. Warm anomalies across the eastern Atlantic
IV. Cold waters surrounding Australia
Let’s look first at the sea surface temperature anomalies:
First and foremost, what’s absolutely screaming out as potentially wanting to take control as the driving force this winter is the significantly warmer than average eastern Pacific waters. This is significant as the warmer than average waters can alter the upper air pattern, promoting a ‘mean’ ridge across the western US and into Canada with a persistent eastern trough downstream. This kind of pattern can be rather persistent in “dislodging” cold Canadian air southeast and can promote a colder to significantly colder than average weather pattern across the Mid West, Great Lakes and into parts of the East. While the warmth across the eastern Atlantic can argue for warmer than average temperatures to kick-off meteorological winter across the eastern seaboard, the makeup of cold and warm off New England and into the Canadian Maritimes can argue for a negative NAO later in the winter (something to consider if we keep this configuration into the mid winter period especially).
All things considered above, here’s our early analog set from a temperature (image 1) and precipitation (image 2) perspective:
While we’ll most certainly have to tweak some of these years as we move through the next 30 days, or so, this serves as a great baseline of what our temperature and precipitation maps may resemble with the finalized winter outlook next month.
We’re fired up for what sure looks like a stormy time of things through the Ohio Valley into the Great Lakes and interior Northeast. Based on the direction the Pacific goes, the potential is there for more of a southeast ridge and warmer look across portions of the Deep South. We’re also beginning to think the West Coast is likely to run warmer than what is shown above based off the Pacific temperature pattern.
The early call here for central Indiana is for a colder than normal winter with above average snowfall. We’ll have our finalized numbers with respect to temperatures and snowfall amounts next month, along with the latest seasonal and climate data included with our updated analog sets.
In the meantime, it might not be a bad idea to take advantage of those early season snow thrower deals out there!
Permanent link to this article: https://indywx.com/indywx-com-preliminary-19-20-winter-outlook/