Summer continues to hang on for September; A look as to why?

By: Lead Forecaster Daniel Crawley

Good Wednesday afternoon,

Summer weather continues to roll on here in the month of September as the southeast US is experiencing above normal temperatures and high levels of humidity for this time of the year. Today’s weather is nice relatively speaking here across Western North Carolina, but as we head into this weekend, the return of heat and mugginess will make the region feel like it still in the midst of mid-summer.

Our weather team has been looking into this persistent pattern and we have some theories as to why the soupy air is hard to budge. 

Just look at the sea surface temperature anomalies in the Atlantic Basin. Pretty much the entire basin near the Continental United States is running varying degrees of above normal. We feel that the overall warmth is playing a role in the 500 mb synoptics of placing higher heights over the Eastern US. The tropics is very quiet for September standards and there’s been zero upwelling of waters to help break down the anomalies.

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The jet stream is not quite ready yet to take on any large buckles to release colder air into the US. A lot of times, you need a catalyst from the tropics for heat transfer into the northern latitudes. With the effects of El Niño shutting down the Atlantic hurricane season, it’s going to require something else to eventually get the wheels turning toward true autumn weather.

For now…continue to embrace the heat and humidity through at least the next 10 days. Temperatures this time of the year average in the 83-84 degree range for highs. We will beat those averages by several degrees.

Long range guidance is trying to hint as cooler weather around Sept 20-23 but we may see that ultimately delayed some more.