Category: PNA

Oct 06

LR Discussion: Pattern Discussion Through The Remainder Of October And Into November…

Updated 10.06.23 @ 7:56a

As we type this, we’re in the midst of the season’s 1st big blast of chilly air. These shots will become progressively cooler (colder) in the coming weeks and months. Speaking of that, we’re also working on a post that we’ll unveil over the weekend looking specifically at the upcoming holiday season and what our analog package/ respective SST configuration says we may have in store this season.

For the purpose of this post, we’ll focus squarely on the pattern through the remainder of October.

As we typically do, the pattern drivers (+ PNA and – EPO) both suggest a ‘mean’ trough should take up shop across the eastern 1/3 of the country over the next couple weeks. What’s interesting is that the updated European Weeklies also suggest this general theme should continue into at least mid-November. Despite a favorable setup with respect to the PNA/ EPO, the model tries to wash out the chill and hints at a ridge down the road. In my humble opinion, this is the model feeding back on itself and once again showcasing an inability to see below normal temperatures in the longer range. We’ve shown time and time again over the summer and even into the early fall where the model is “forced” to cool the closer we get to a given period and believe that will, once again, be the case this go around, especially with the anticipated positive PNA and negative EPO.

The Pacific North American pattern (PNA) is expected to remain in a positive state through the majority of the upcoming 5-6 weeks.
The East Pacific Oscillation (EPO) is anticipated to remain largely in a negative state through the upcoming 5-6 weeks.

The upper pattern, illustrated with last night’s European Weeklies, is one that breaks the trough down towards Halloween. While there is a possibility of some brief warming around this timeframe, I suspect we’ll once again look back at the model having to correct colder over the east as we rumble into November. More on that in a moment.

Week 1: 10/5 through 10/11

Week 2: 10/11 through 10/18

Week 3: 10/18 through 10/25

Week 4: 10/25 through 11/1

The period ends with a warmer look around Halloween and while this is on the table, it’s also a look that should promote building heights over AK and western Canada and another period of blocking with a subsequent cold trough developing over our neck of the woods and the central/ east as we rumble through into November. The model is seeing the building heights, but not picking up on the magnitude of a downstream trough and associated colder pattern, IMO. Frankly, this 500mb look is capable of producing very cold weather sometime during mid-November and I suspect the model will have to start playing catch up as we move forward.

Permanent link to this article: https://indywx.com/lr-discussion-pattern-discussion-through-the-remainder-of-october-and-into-november/

Sep 28

VIDEO: Dry Times Return; “Jailbreak” Pattern Next Week…

Updated 09.28.23 @ 7:50a Our warm open to October will reverse in big time fashion week after next. In other exciting news, our annual winter outlook will be posted Sunday…

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Permanent link to this article: https://indywx.com/video-dry-times-return-jailbreak-pattern-next-week/

Sep 24

VIDEO: Better Rain Chances Return And Doubling Down On The Colder Mid-Oct Pattern Shift…

Updated 09.24.23 @ 10:44a

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Sep 23

Cruising Into A Warm Close To September/ Open To October; Mid-Month Changes Brewing?

Updated 09.23.23 @ 7:50a

Dry conditions will prevail through 99.9% of the weekend and for most, 100% of the time. A few very light showers may sneak into western counties Sunday night, but light is the key word. With such a dry airmass in place, most of this activity is expected to arrive in a weakening state.

The temperature pattern is “easy peasy” this week as unseasonably mild temperatures dominate. An extended stretch of highs around 80° can be expected in the week ahead.

An upper low will pivot out of the Mid West and through the Ohio Valley midweek. This will deliver more in the way of unsettled weather for our neck of the woods, but we’re still not overly excited about rain chances.

Scattered showers will build into the picture Wednesday and Thursday, courtesy of the aforementioned upper low pressure system. From this distance, rainfall totals are expected to be light (mostly in the 0.10″ to 0.25″ range) and certainly not uniform in nature.

As we head into next weekend and the beginning of October (can you believe it?!), the ridge will expand overhead and lead to a return of quiet and milder times.

Down the road, as mentioned in this week’s long range report, I still would be very suspicious of the warm paint blob shown on most modeling towards mid-October. The thinking here is the negative EPO and positive PNA will begin to do work, leading to a fairly sizable shift in the ‘mean’ pattern…

Permanent link to this article: https://indywx.com/cruising-into-a-warm-close-to-september-open-to-october-mid-month-changes-brewing/

Sep 22

Long Range Outlook Into October: Reason To Be Suspicious Of The Warm Look…

Updated 09.22.23 @ 10:41a

The pattern over the next 10 days will continue the same warmer than normal theme we’ve grown accustomed to as of late. Keep in mind that “normals” have now fallen into the lower to middle 70s for highs and lower 50s at night. Certainly far from a “blow torch,” but temperatures will run 5° to 10° above the norm as we put a bow on September.

Short-term rain chances will be handled in our daily videos. Guidance continues to differ widely on our mid week system. Needless to say, we’re not overly optimistic on the wetter solutions as of now, but will closely monitor to see if more consistency develops down the road.

As a whole, the pattern continues to look drier than normal over the next couple weeks overall.

Week 1

Week 2

While guidance continues to look warm into early and mid October, I have to raise an eyebrow based on the latest teleconnection trends. We note the EPO trending negative while the PNA pops positive. These drivers should force a colder look Week 2 into Week 3 and I would suspect guidance will cool significantly as we get closer.

Further down the road, it’ll be important to keep tabs on western Pacific typhoon activity and the Madden Julian Oscillation. There are signs we may finally start to see the MJO become more of a player in the pattern towards mid October. Time will tell.

In the meantime, keep a close eye on guidance Week 2 into Week 3 as this will be the first real test case to revisit so far this meteorological fall season…

Permanent link to this article: https://indywx.com/long-range-outlook-into-october-reason-to-be-suspicious-of-the-warm-look/