As we roll into the second half of October, a look at the primary pattern drivers suggests there should be a lack of any sort of sustained above normal temperatures.
The PNA (image 1) should remain mostly in a positive state over the next couple weeks while the EPO (image 2) is expected to be in a neutral to negative state.
Furthermore, the MJO is forecast to sneak into Phase 1 late month. This is the correlation in October:
It’s hard to find much at fault with the NEW JMA Weeklies posted earlier today.
Temperatures
Week 1
Week 2
Weeks 3-4
Precipitation should run average to slightly below normal over the span of the upcoming (2) weeks:
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…
September has opened significantly warmer than normal across the northern Plains and to a lesser extent into the southern Plains and along the northern tier. Indianapolis is running 5° above average through the 6th. We’ll chip away some at those toasty anomalies over the course of the next week, but still anticipate the month finishing slightly warmer than normal as a whole. We’re also running dry- more than half an inch below normal to open the month.
As we look ahead to the upcoming couple of weeks, the combination of the Madden Julian Oscillation sneaking into Phase 4, combined with a strongly positive PNA should help lead to more of a trough across the eastern portion of the country.
The NEW JMA Weeklies show that trough and associated cooler pattern (not cold by any means, but instead slightly below normal overall) taking up shop in the Week 1 and Week 2 time period below.
Week 1
Week 2
The latest ensemble guidance is also on board with the more seasonal look, especially compared to how the month opened.
Week 1
Week 2
Overall, the dry start to the month is anticipated to persist through the remainder of September as a whole.
Jumping ahead, the JMA seasonal data also updated today. In short, the model shows a warm fall giving way to a warm start to the winter before potentially taking a colder mid and late winter turn. Still far too early to put much stock in the specifics from this distance. The next couple of months will be very telling with the migration (or lack thereof) of warmest central PAC sea surface temperatures along with modeled trends deeper into the winter. Long ways to go; stay tuned…
JMA meteorological (Dec. through Feb.) winter idea:
Updated 08.31.23 @ 7:45a The extended stretch of calm, quiet conditions will allows us to start looking ahead to the upcoming winter in earnest over the upcoming several days. We’ll…
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We’re only a few days away from meteorological fall. Despite what the calendar says, Mother Nature will provide “bonus” heat and plenty of dry times as we rumble through the next few weeks.
The Madden Julian Oscillation (MJO) looks to “wake up” and amplify into the notorious warm phases for September.
The PNA (Pacific North American pattern) is going to crash negative and fits right into the warm pattern driver theme.
Medium and long range modeling shows the upper ridge building and expanding northeast with time over the next couple weeks. Unseasonably hot weather will accompany this pattern evolution.
Widespread drier than normal conditions should also prevail through the upcoming few weeks.
Even as we progress into the final few days of the month, extended long range guidance maintains the warm to hot theme.
It’s really not until we get to October that the pattern should begin to change in more significant fashion and make up for lost time with respect to cool, crisp air…
