Category: PNA

Nov 17

More On The Cold Close To November…

Updated 11.17.23 @ 11a

The stars are all aligning to drive a significant shift in the overall regime towards one that should yield cooler (and, at times, colder) than normal temperatures as we navigate the back half of the month.

First, we have the MJO. Note how we’re set to slide into Phases 1 and 2 between now and end of the month.

These are progressively cold phases this time of year. Phase 1 has residual warmth across the Northeast (more seasonable here on the home front) before Phase 2 becomes overwhelmingly cold.

We then have the combo of the negative EPO and positive PNA. Both cold signals for our neck of the woods.

It’s no wonder model guidance is jumping on the persistent eastern trough to close out the month.

At some point in the 8-12 day period, I’d anticipate a true dislodge of true early season arctic air to get involved in the pattern. Think lows into the upper 10s, lower 20s and highs in the 30s. Still far too early to get specific with snow chances, but they will come before month’s end.

Stay tuned…

Permanent link to this article: https://indywx.com/more-on-the-cold-close-to-november/

Nov 14

VIDEO: Colder Late Month Changes…

Updated 11.14.23 @ 6:45a

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Permanent link to this article: https://indywx.com/video-colder-late-month-changes/

Nov 12

Sunday Morning Rambles: Thanksgiving Week Continues To Trend Active…

Updated 11.12.23 @ 11:13a

As quiet as this week will be, overall, it continues to look like Thanksgiving week won’t provide the same fortune. As mentioned yesterday, there’s no reason to waste time describing the day to day “rinse and repeat” regime up until Thursday. That’s when a frontal boundary will sweep through the Ohio Valley with gusty winds (30-40 MPH) and an opportunity of showers Thursday night into Friday. Moisture return continues to look unimpressive. Best chances of measurable rain (0.10” – 0.25”) will come from Indianapolis and points east during this timeframe.

The next couple weeks will run milder to much milder than normal.

Week 1

Week 2

The quiet week we will enjoy this week will be replaced with a much more active time of things in the days leading up to Thanksgiving. Look for a potentially potent and large scale storm system impacting our weather with rain and gusty winds early to mid next week. Note the significant change between Week 1 and Week 2 precipitation below. More details to come as we go through this week.

Week 1 precipitation anomalies


Week 2 precipitation anomalies

We watch the EPO trends closely for the threat of potentially colder changes longer term.

Until the PNA and MJO follow suit, “tread with caution” on any wholesale big colder shifts. All in all, this predominant regime should hold firm into the 1st half of December.

Permanent link to this article: https://indywx.com/sunday-morning-rambles-thanksgiving-week-continues-to-trend-active/

Nov 09

LR Update: Thanksgiving And Early December…

Updated 11.09.23 @ 10:49a

With Thanksgiving only 2 weeks from today (incredibly hard to believe), we’re able to start to get a better idea on the overall weather pattern as the “official” kickoff to the holiday season nears. The first point we want to drive home is that we should begin to see a much more active regime evolve during this 2 week period. From a temperature perspective, the pattern overall continues to look milder than average, but there will be a couple opportunities for transient pops of colder air, potentially around the all-important Thanksgiving holiday, itself.

Note how modeling sees the more active pattern evolving over the next 3-4 weeks (green represents above normal precipitation). – A significant change not only for our neck of the woods but certainly for our friends and neighbors down south (badly needed for a region suffering an expanding drought. Speaking of which, all of the dry/ droughty southern tier should reverse in significant fashion as the active Nino storm track gets going over the coming months. As the pattern continues to evolve into the ‘24 spring and summer, the south-central severe drought will be erased.

Despite attempts of troughs to roll into the Ohio Valley, they will struggle with staying power over the next 3-4 weeks. The latest JMA Weekly product and Euro/ GFS ensemble blend looks very solid given where the pattern drivers currently reside.

Week 1

Week 2

Weeks 3-4

The pattern drivers of a primarily positive EPO, negative PNA, and MJO in 8/1 (all unchanged from our post earlier this week) all suggest a predominant eastern ridge, western trough placement over the upcoming 2-3 weeks.

We’ll continue to keep close tabs on the regime, especially centered on 11/22 – 11/26.

Make it a great Thursday!

Side note: Confidence is increasing that this Nino will evolve into a central-based event which will up the chances of colder/ snowier prospects come late December and on into January. More on that later next week in a more extensive update specific to this transition.

Permanent link to this article: https://indywx.com/lr-update-thanksgiving-and-early-december/

Nov 07

An Overall Warm Ride Into The Thanksgiving Holiday; Any Changes On The Horizon?

Updated 11.07.23 @ 5:15a

Despite a weekend setback that will continue into the early portion of Week 2, updated forecast model data continues to scream that we’ll run above to well above normal as the Thanksgiving holiday nears.

The pattern drivers support the warmer than normal call over the next couple of days. Note the primarily positive EPO and negative PNA.

This should help keep the ‘mean’ ridge position across the upper Mid West and Great Lakes over the next couple of weeks.

We’ll keep close eyes on the negative trend of that EPO towards the end of the period (image 1 above) to see if it continues in the coming days. If so, there’s the potential we could pull the anticipated western trough east in perhaps a bit quicker fashion than models currently see (say the last week of November, potentially).

As it is, another big pattern driver, the Madden-Julian Oscillation will begin to rev up in the coming days. A circle through Phase 7/8 this time of year supports the warm signals shown from the PNA and EPO.

Permanent link to this article: https://indywx.com/an-overall-warm-ride-into-the-thanksgiving-holiday-any-changes-on-the-horizon/