If you are a heat and humidity hater and your air conditioner has become your best friend, it's time to give that friendship (and your wallet) a break. Early indications from extended models for the next couple of weeks are suggesting our friend from Canada (though foe in the winter), the upper low pressure and trough over eastern Canada, is going to exude its influence south into our neck-of-the-woods over the coming days. I noticed the pattern change about a week ago at the edge of model time period, about 12-14 days out. One has to be careful in jumping on the bandwagon of such a change that is so contrary to the recent stubborn and strong ingrained pattern. These abrupt changes tend to show up in model data late in the prevailing season, sort of "rushing in" the season in the wings.
These changes in model trends that show up way out in "la la land" (or as some at the NWS-DTX "affectionately" referred to it as "Deedler-land") more often than not, do eventually happen but their timing can be most problematic. I am a weather "enthusiast" (spelled "n-u-t") about past and future upper air and surface patterns and their correlations. That is, researching and examining past patterns and correlating them to present and future projections. Projected teleconnections can be compared to past patterns for feasibility and accuracy or put it simplicity: Does the overall general forecasted upper air pattern "look right" when compared to past Climatic patterns?
Ok Ok Ok... Back to the future
Upper air projected patterns continue to show a notable change in the upper air flow across the upper Midwest and Great Lakes in the coming few weeks. Basically a lowering of heights aloft and cooling at the surface due to an expansion of the upper low in eastern Canada. This, in turn, would encourage a more dominant west-northwest flow rather than the south-southwest flow seen for several weeks now.
The first wave of cooler air has brought beautiful weather across the region with highs in the 70s and lows in the 50s. Looking out further shows the second wave of cooler weather coming late in the weekend /21st/. The upper wind flow projections can be seen below on Sat August 20th at 8am EDT. Ahead of this front, look for temperatures to warm back up well into the 80s by mid week. Normal highs this time of year are in the lower 80s.
In my earlier article I stated, "Will this cooler trend prevail through the end of the month? I doubt it but I will say this, more often that not, I've noticed the first fleeting hint of the upcoming autumn season change, surfaces in mid August." This too appears on track as the ridge attempts to build back into the region for a longer stay late in the month. This will bring warmer weather back to the region.