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February 2019 archive
Permanent link to this article: https://indywx.com/2019/02/15/all-access-video-update-on-the-longer-range-and-honing-in-on-short-term-systems/
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 14
All-Access Morning Video Update: Looking Into Next Week & Reviewing The Latest JMA Weeklies…
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Permanent link to this article: https://indywx.com/2019/02/14/all-access-morning-video-update-looking-into-next-week-reviewing-the-latest-jma-weeklies/
Feb 13
Disruption In The Force Or Just Noise?
Our longstanding call has been for the period of early to mid-February to feature a “transitional” pattern before locking into one last cold, stormy period for the winter during the 2/18 through 3/10 time frame. The reasoning behind this idea has been stated multiple times in previous updates.
However, there’s no denying that today’s 12z ensemble update (both from the GEFS and EPS) has rattled us a bit with that idea. The GEFS and EPS are in very good agreement at 500mb:
This is in the face of Phases 8 and 1 from an MJO perspective:
Furthermore, the sudden negative “jolt” in the SOI (Southern Oscillation Index) also favors a significant period of cold, stormy weather, locally:
Please understand this isn’t us changing our ongoing forecast that’s out there, but instead making sure we’re presenting a 100% transparent idea from two of the most highly respected ensemble products out there (that have been generating a lot of attention today with this output). We prefer to give it another few days before altering our medium and longer term forecast to see if any sort of consistency can develop.
At the end of the day, this may be a situation where the resistance from the SE ridge puts up enough of a fight to lead to a lack of “suppression” from the hyperactive storm track currently in place, and instead continuing the busy storm track into the TN and Ohio Valley regions as cold air presses.
Rest assured, you’ll be the first to know if a wholesale medium to long range forecast change is required here. Stay tuned.
Permanent link to this article: https://indywx.com/2019/02/13/disruption-in-the-force-or-just-noise/
Feb 13
All-Access Morning Video Update: Tracking 3 Storm Systems And An Overall Shift To A Colder Pattern…
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Permanent link to this article: https://indywx.com/2019/02/13/all-access-morning-video-update-tracking-3-storm-systems-and-an-overall-shift-to-a-colder-pattern/
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 12
All-Access Video Update: Timing Out The Wintry Threats In The Upcoming Week (And Beyond)…
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Permanent link to this article: https://indywx.com/2019/02/12/all-access-video-update-timing-out-the-wintry-threats-in-the-upcoming-week-and-beyond/
Feb 11
No Rest For The Weary; Reviewing The New European Weeklies…
In the short-term, rainfall will increase in overall coverage and intensity as we progress through the overnight and on into Tuesday morning.
Most central Indiana rain gauges can expect to accumulate between 0.50″ and 1.00″ tonight into Tuesday morning. Heavier amounts will be found downstate.
We continue to closely monitor the precise track of vigorous upper level energy that will result in a narrow, but more intense, band of snow Tuesday afternoon into the evening hours. While temperatures will be marginal, it wouldn’t shock us in the least by a wet 1″ to 2″ stripe of snow that’s laid down in a narrow southwest to northeast corridor and this will warrant close attention with subsequent model updates overnight. An early idea of where this may be is below:
Regardless of where this potentially more significant snowband lies, all of us will get in on the “backlash” snow showers/ squall action Tuesday evening and night.
Looking ahead, continued active times loom. We’re tracking additional storms Thursday night into Friday and again over the upcoming weekend. Yet another storm is slated for an arrival early parts of the following week. As cold air continues to get more involved, these storm systems will be plenty capable of dealing out more in the way of wintry “fun and games,” but the pattern is “hectic” right now and each storm will have to be dealt with as they come. Understanding that it’s still in the 6-10 day time period, the storm early next week seems to have the greatest potential of widespread wintry implications of significance. This is given the overall pattern evolution away from the “transitional” period we’re currently in and squarely inside the cold/ wintry window we’ve been outlining from 2/18 through 3/10. Time will tell…
European Weeklies
The new European Weeklies show the cold currently confined to the PAC NW and northern Plains “spreading out” and encompassing a more widespread portion of the country- especially from the Appalachians and points west (but periodically making it as far east as the coast). The cold is forecast by the model to dive deep into the southern Plains and into the Southeast as we move into the latter parts of February into early March. Perhaps the biggest change from tonight’s update from Thursday is the idea that the cold will linger deeper into March than previously thought. (Please note this doesn’t change our current *official* idea of cold lifting by mid-month, but simply just rehashing model output). Let’s see if we can get some consistency to develop before altering our current forecast.
From a teleconnection stand point, the model does take the NAO neutral to negative late Feb into early March before returning things solidly positive by mid-month.
Permanent link to this article: https://indywx.com/2019/02/11/no-rest-for-the-weary-reviewing-the-new-european-weeklies/
Feb 11
Heavy Rain Arrives Tonight; Accumulating Snow Band May Setup Shop For Portions Of The Area Tuesday…
A busy pattern continues with heavy rain tonight. Attention then shifts to the potential of a band of accumulating snow, associated with a vigorous piece of upper level energy Tuesday…
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Permanent link to this article: https://indywx.com/2019/02/11/heavy-rain-arrives-tonight-accumulating-snow-band-may-setup-shop-for-portions-of-the-area-tuesday/
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/