After an unseasonably cool weekend, significant late season heat will return next week.
Note the ridge expand over the eastern portion of the country next week.
To no surprise, the EPO pops positive and this really helps drive the warm mid-September pattern.
Positive EPOs in September favor warmth from the OHV, Mid Atl and into the Northeast.
The question then becomes “how long does the late season heat last?” As the EPO trends negative, cooler times would be favored as we move into late September. We’ll keep a close eye on things.
For now, those not ready to say goodbye to summer will be in luck next week with highs around 90 and lows in the upper 60s to lower 70s…
A few opportunities (today and Sunday) for showers can be expected over the next few days, but these won’t amount to much and some may not see any rain of significance. Better rain and storm chances will return the middle of next week.
A cold front will sink south across the state this evening. As the front moves through the area, we expect thunderstorms to increase in coverage and intensity across northern Indiana over the next few hours. These storms should push off to the south during the overnight, weakening as they do so. We still aren’t expecting much in the way of widespread severe weather across immediate central Indiana.
Once the front passes, northwest winds will take over during the predawn hours and help push a drier and cooler brand of air south into the region.
The cold front will move through central Indiana during the overnight hours.
Thereafter, get used to unseasonably cool air, to the tune of what we’d normally expect by late September, for the 2nd half of the week- including this weekend. Mostly dry weather is expected to prevail through the period.
As we look ahead to next week, moderating temperatures are expected next Tuesday and Wednesday, including lower to middle 80s. That said, we do have questions if the warmth will have staying power.
We note the MJO “toying around” with the warmer Phase 6 for a time before returning to Phase 5 (a cooler phase this time of year).
Add in the fact that the EPS and GEFS are in disagreement in handling the EPO in the medium term and this results in lower confidence in the overall staying power of the warmth come mid month.
Unfortunately, this time of year, the tools we can really “lean on” for indications of where the longer range pattern will head are limited (compared to late fall through early spring). That’s when we can really focus on the other drivers such as the AO, NAO, PNA, recurving WPAC tropical activity, etc.
As such, while we continue to believe the pattern trends warmer after the cool spell into the weekend, patience is required with respect to the staying power of said warmth…
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The short-term period will be dominated by a cooler than normal theme as we put the final touches on August and open September.
This will only serve to push those already below normal for the month even cooler than average and turn a lot of the area bordering these cool anomalies “over the top” from seasonal to slightly cooler than normal by month’s end. Meanwhile, warmth will continue to dominate along the coasts
Here’s a look at month-to-date temperature anomalies, compared to our initial August forecast (issued July 21st).
The negative EPO suggests any sort of warmth will be hard to come by and transitional through the 1st 1/3 of the month.
After a wet time of things as of late, we’ll dry things out the middle part of the week. A couple of moisture-starved and rather weak systems may lead to scattered showers Friday and again at times over the holiday weekend, but significant rain isn’t anticipated. We would agree with the drier than average theme displayed from the most recent CFSv2 Weekly product to open September:
The one potential “fly in the ointment” to the dry open to September would be whatever comes from current Tropical Storm Dorian (moving through the Windward Islands as of this update). There’s relatively good model agreement that Dorian will move northwest and eventually be in a position to impact the eastern Florida coastline by the Labor Day weekend as a Tropical Storm.
It’s far too early to speculate from this point, but the pattern may promote Dorian to then track into the Gulf of Mexico. While unlikely Dorian’s remnant moisture ever impacts our immediate region, this will be something that we’ll keep an eye on over the next week to 10 days.
