August can be the cruelest month (apologies to T.S. Eliot fans). Just when we've been teased by a few cool mornings that reminded us that fall is just around the corner, summer can jump up and bite you with some of the worst heat and humidity we've seen all summer. Such would seem to be the situation shaping up for the coming week or two.
The upper air pattern is transforming into something we haven't really seen much all summer - a large high pressure ridge forecast to build over the Southeast at the same time a deep, cooling trough digs in over the formerly torched Northwest. (Those features go hand-in-hand in something meteorologists call teleconnections.) Once a ridge takes over, don't look for any more cold fronts or major storm systems to make it in here with any kind of strength.
Tropical systems, though, love this kind of pattern, though right now the Atlantic is mostly quiet. I'd look for that to change as we get closer to September and the peak of hurricane season.
Although an August upper ridge tends to lead to hot, dry weather, we could still get thunderstorms, at least in tthe early stages of this pattern transition. Moisture is today (Sunday) pouring back into the Gulf region, dew points are on the rise, and air mass thunderstorms will be scattered about on a daily basis at least through midweek. After that we could dry out and heat up, as an upper ridge tends to promote a stable atmosphere if located nearby.
Indications are this could bring some of the hottest weather of the whole summer. Model forecasts are hinting at upper 90s by late week (follow the First Alert team's actual forecasts as the week goes by here). The highest temperature in Columbus so far this summer was 97º all the way back on June 20.
This kind of setup is not that unusual; while our normal highs and lows start falling in late August, the temperatures can remain well above average if we get underneath a ridge. It happened in 2010 when record-smashing heat lasted well into September, and in other prior years.
This year I don't know that the pattern will stick around for too long. The jet stream remains active as it has been all summer, which would promote an eventual breaking down of the ridge and a return to more normal late summer weather. But that may not happen for a couple weeks, and by then we're into September.
So deal with the heat, haze, and humidity for awhile, and wish for a few thunderstorms or even a tropical storm to come in and bring some temporary relief from the most potentially intense hot spell we've seen this summer.