Category: Unseasonably Cool Weather

Another Big Shot Of Cool Air Dialed Up, But What About Rain?

“Transient” warmth and continued dry weather will carry us through the short-term period, but don’t get used to it.

Another sharp trough will plunge into the eastern portion of the country next week and offer up the coolest air of the young fall season, along with better chances of at least light rain. The upcoming cool blast is in response to the positive PNA and negative EPO.

The airmass associated with this trough next week will be early November-like for a day or two, and well below late September/ early October norms for the remainder of the period.

Unlike our last trough, this one will feature more upper level energy and this combined with the unseasonably cold air (at the surface and aloft) will generate periods of at least light rain during the early part of the work week.

We’re not talking about a lot of rain, but a badly needed 0.25″ to 0.50″ is better than nothing.

Looking farther out, there’s reason to buy into the cooler than normal pattern having staying power into the first 1/3 of October, and perhaps beyond. More on this in future updates. Make it a great Tuesday!

Permanent link to this article: https://indywx.com/2020/09/22/another-big-shot-of-cool-air-dialed-up-but-what-about-rain/

VIDEO: Talking Our Next Chance Of Rain; Early November-like Chill Next Week…

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Permanent link to this article: https://indywx.com/2020/09/21/video-talking-our-next-chance-of-rain-early-november-like-chill-next-week/

VIDEO: Turning Briefly Warmer Before Another Chilly Plunge…

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Permanent link to this article: https://indywx.com/2020/09/20/video-turning-briefly-warmer-before-another-chilly-plunge/

VIDEO: Chilly Start Sunday AM; Keeping Close Eyes On Interaction Between Approaching Trough Late Week And Remnant Tropical Moisture…

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Permanent link to this article: https://indywx.com/2020/09/19/video-chilly-start-sunday-am-keeping-close-eyes-on-interaction-between-approaching-trough-late-week-and-remnant-tropical-moisture/

Quiet For Now, But Attention Warranted In The 7-9 Day Window…

The big story in the immediate term is centered squarely on the temperature forecast. Frost Advisories are up for our friends across northern parts of the state, northwestern OH, and into southwestern MI. Even a few folks outside of the city, itself, can expect patchy frost (a few weeks early mind you, and another byproduct of the recent dryness) across central Indiana.

There’s no reason to waste a lot of pixels on the short-term forecast as quiet conditions prevail. High pressure will remain in control for the upcoming work week with slowly moderating temperatures. We’ll go from below, to seasonal, to slightly above normal by week’s end.

The next “problem” arises by next weekend as forecast models sort out what to do with remnant tropical moisture from now TS Beta and an approaching cold front. In this morning’s client video (never posted due to the connectivity issues), we walked through the various solutions. We’ll be “back to normal” from a video perspective late tomorrow and appreciate your patience more than you know.

There’s two windows that are open late next week/ next weekend, including the Deep South and the Ohio Valley dealing with remnant tropical moisture. Given the overall pattern, we favor the southern solution from this distance, but should Beta “dilly dally” in the western Gulf, there will be an opportunity for that next approaching trough to pull that remnant tropical moisture northward into an area desperately needing rainfall. Stay tuned. Interestingly, the European and GFS both agree on the northern trend at 12z.

Notes and Asides: We’ll be back at home base tomorrow night after being down on the Gulf for the past week and will resume normal video production at that point. Despite the quiet times right now, it’ll be interesting to see how things begin to ramp up late next week. Much more later. Have a relaxing Friday evening.

Permanent link to this article: https://indywx.com/2020/09/18/quiet-for-now-but-attention-warranted-in-the-7-9-day-window/

Long Range Update: Extended Dry Pattern Rolls Along; New Winter Seasonal Data Is In…

Unfortunately there likely won’t be any significant changes to our precipitation pattern until late autumn and winter. Until then, we’ll have to take any drop of rain we can find. Once the pattern flips though, it may do so in quick and rather dramatic fashion (still expecting a wet winter).

The consensus of long range data shows the dry pattern continuing over the upcoming few weeks, including the JMA Weeklies, CFSv2 Weeklies, and ensemble products.

Analogs and other teleconnections support this dry theme. At least in the immediate range (through mid October) the only way to bust up this dry pattern is to get tropical moisture involved.

The new JMA Weeklies maintain the ‘mean’ ridge position across the West for the majority of the upcoming few weeks, but there will likely be attempts to expand the ridge across the northern tier Week 2 and 3 that would lead to at least transitional periods of much warmer air, after the cool period in the short term.

The model sees the ridge expanding Weeks 3-4 and the associated warmth that spreads east after the chilly regime.

The new JAMSTEC seasonal data is also in and maintains a warm look this winter. A lot of this has to do with an expected persistent southeastern ridge. We agree with this but, as is the case each winter, there will be challenges that have to be dealt with.

We also agree with the active storm track through the Ohio Valley and associated well above normal precipitation in the December through February period.

Permanent link to this article: https://indywx.com/2020/09/17/long-range-update-extended-dry-pattern-rolls-along-new-winter-seasonal-data-is-in/

VIDEO: Cooler Air Met With Continued Dry Conditions; Latest On Sally…

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Permanent link to this article: https://indywx.com/2020/09/14/video-cooler-air-met-with-continued-dry-conditions-latest-on-sally/

VIDEO: Soon-To-Be Sally Heads For The North-Central Gulf Coast; Pattern Takes An Active Turn Towards Late Month…

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Permanent link to this article: https://indywx.com/2020/09/12/video-soon-to-be-sally-heads-for-the-north-central-gulf-coast-pattern-takes-an-active-turn-towards-late-month/

Long Range Update: Walking Through The Back Half Of September…

We believe the pattern during the 2nd half of the month will be driven by the MJO and PNA. The MJO is forecast into Phase 6 and 7 by the 18th-24th time frame.

Phase 6 is quite warm, but notice how the chilly air begins to push during Phase 7.

Neither phase is overly wet, but there’s hope compared to how dry it’s been over the past 2-3 weeks.

Interestingly enough, after a “neutral” phase with the PNA, both the GFS and European ensemble products predict a strong positive shift just after the 20th. This suggests to me that the week starting around that point should feature more widespread and stronger chill, compared to normal.

Let’s look at the latest model guidance, starting with the European ensemble:

Week 1 is still warmer than normal across our region, but notice the strong cooling by Week 2 (Sept. 18th-25th time frame).

The GFS ensemble is similar during the Week 1 and Week 2 time frame.

Given that strong PNA by late month, it wouldn’t surprise me to see these anomalies grow cooler as time gets closer during that Week 2 period.

Overall, the pattern continues to look dry, although there should be a better shot of rain/ storms as the cold front moves into the region that will ultimately deliver the much cooler air late month.

Permanent link to this article: https://indywx.com/2020/09/11/long-range-update-walking-through-the-back-half-of-september/

VIDEO: Dry Conditions Remain, Overall, Through The Short-Term; Eyeing A Stronger Cold Front Days 8-10…

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Permanent link to this article: https://indywx.com/2020/09/10/video-dry-conditions-remain-overall-through-the-short-term-eyeing-a-stronger-cold-front-days-8-10/

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