June 12, 2020 archive

Long Range Update: Timing Out When The Dry Pattern Breaks Down; 2nd Half Of Summer Chatter…

The balance of the upcoming 7-10 days will feature bone dry conditions across central Indiana. A fast moving disturbance will drop southeast Saturday and could spawn a scattered shower across central Indiana, but we believe the more concentrated rain activity will remain to our east and southwest. If you do see a Saturday shower, count yourself lucky! This disturbance and associated cold front will serve to reinforce the dry airmass currently in place, along with bring temperatures down another couple of “notches” for the weekend (wouldn’t be surprised if some outlying areas get into the 40s Sunday or Monday mornings).

As we look ahead, a ridge of high pressure will dominate next week’s weather pattern. An extended stretch of dry (pleasant humidity levels), sunny days can be expected with a slow warming trend.

A ridge of high pressure will dominate our weather pattern next week as a “cut off” low tracks into the Southeast and Carolinas. The end result will be an extended period of dry weather for our region.

Things begin to get a little more “murky” late next week as forecast model solutions differ significantly. The new GFS forecast model drives a cold front into the Ohio Valley before stalling out as multiple disturbances ride along the boundary. This would lead to needed rain (and potentially heavy rain at that) late next week into next weekend. Meanwhile, the European model isn’t nearly as excited about this wet weather potential. The reality likely lies somewhere in between and we’ll trend our forecast wetter late week, but hold on the heavy rain threat for now. Stay tuned.

With that said, we do believe (given the pattern drivers discussed below) that the wetter trends shown on the GFS ensemble data in the Week 2 (and beyond) time frame has validity.

Precipitation anomalies Days 6-12
Precipitation anomalies Days 10-16

The latest JMA Weekly data also shows a similar wet idea during this time period.

As we look at the PNA and EPO, the transition in both teleconnections next week do give credence to the wetter them shown above during the said period.

Additionally, the positive PNA (image 1 above) and negative EPO (image 2 above) argue for the possibility of another period of cool weather to wrap up the month. This would come after transitional heat late next week.

The GEFS is cooler than the European during this time frame. Given the above, it wouldn’t surprise us if the Euro is forced to cool as we get closer to this period.

We’re undoubtedly entering into a critical time frame for the remainder of the summer. The upcoming couple of weeks will go a long way in determining the balance of the rest of this season. Despite the short-term dry pattern, we do believe (at least locally), rain will return before things get out of hand. The same may not be able to be said just to our west. It’s there (more from the Rockies into the Plains) where we think July heat will build in more significant fashion with the drier soils.

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