Category: PNA

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Permanent link to this article: https://indywx.com/2020/10/12/video-getting-to-be-that-time-of-year-pattern-turns-busier-to-close-october/

Oct 08

Long Range Update: 2nd Half Of October And Open To November…

• Filed under Autumn, Client, Ensemble Discussion, EPO, Forecast Discussion, Forecast Models, Harvest '20, High-latitude Blocking, Long Range Discussion, MJO, PNA, Unseasonably Cool Weather, Unseasonably Warm

• October 8, 2020

As the fall season “matures” the same MJO phase last month can lead to a much different weather pattern this month (November and so on). Note how the latest European monthly MJO model takes things through 5, 6, 7, and 8 by early November.

With greater amplitude, I’d say this would take the driver seat behind the pattern evolution into early November, but that’s not the case. Instead, we’ll want to continue to closely monitor the happenings with the EPO and PNA.

Both are pegged to move into favorable phases to bring the chill back into the East as we move through late October.

We think next week will feature a “step-down” process to a much chillier following week (Oct. 17th-23rd).

The new JMA Weeklies into the office this morning show a similar pattern evolution:

If anything, I’d expect this model to cool further over time in that Weeks 3-4 period. It’s also interesting to see the high latitude blocking shown to remain intact (that can really begin to have more of an impact downstream once to November).

Unfortunately, it’s a continued dry pattern. We’ll have more frequent frontal passages as we move through the back half of the month, but these will likely be moisture starved for the most part. It still doesn’t look like a wholesale wetter pattern will kick in until later in November.

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Permanent link to this article: https://indywx.com/2020/10/08/long-range-update-2nd-half-of-october-and-open-to-november/

Permanent link to this article: https://indywx.com/2020/10/06/video-delta-will-become-a-major-hurricane-today-more-on-this-and-reasons-why-our-mid-october-trough-should-trend-stronger/

Permanent link to this article: https://indywx.com/2020/10/04/video-frosty-start-monday-gives-way-to-moderating-temperatures-this-week-keeping-close-eyes-on-the-gulf/

Permanent link to this article: https://indywx.com/2020/09/29/video-unseasonably-chilly-first-1-3-of-october-but-then-what/

Permanent link to this article: https://indywx.com/2020/09/26/video-summer-like-weekend-gives-way-to-the-chill-of-autumn/

Permanent link to this article: https://indywx.com/2020/09/23/video-reasons-to-believe-the-chill-to-open-october-has-some-staying-power/

Sep 22

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

• Filed under Autumn, Client, EPO, Forecast Discussion, Harvest '20, PNA, Rain, Unseasonably Cool Weather

• September 22, 2020

“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!

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