Summer Backs Off from the Northeast as Cooler Temperatures Take Over

Is summer done for the season in the Northeast? This is what meteorologists are saying about when and if you can expect the hot weather to return to this corner of the nation.

Cooler Temperatures Expected to Linger in Short-Term for the Northeast

The summer got off to a hot start in the Northeast in June with relentless heat and humidity that lingered in the region for weeks. This pattern came to a screeching halt last week after Tropical Rainstorm Debby pushed up the East Coast and ushered in wetter and cooler weather. Forecasters believe that the cool and less humid air will linger over the Northeast for a bit longer.

The influx of cooler temperatures are the result of a persistent dip in the jet stream that will stick around from the Midwest and into the Northeast for the next few weeks. This type of jet stream configuration generally keeps hot air to the south. While there will be periods when the temperatures surge upward and humidity levels rise slightly, these times will not persist across the Northeast.

In addition to the change in the jet stream pattern, the sun's power tends to diminish in August. The strong sunshine that marks June and July starts to dissipate as the fall nears closer. Lastly, the wet grounds left behind by Debby work to soak up the sun through the process of evaporation. This effect diverts the power of the sun from the air and to the ground.

This is typically the time of the year when the historical average temperatures begin to inch downward. Shorter days and longer nights are partially to blame for the lower overall temperature readings. As a result, any deviation in the jet stream can translate to lower temperatures across the board.

How Long Will the Cooler Than Average Temperatures Linger?

The long-range forecast is calling for the same jet stream pattern to keep the cooler conditions entrenched in the Northeast until the last week of August. And while it may seem too far away to impact the weather in the U.S., the forecast of a typhoon moving away from eastern Asia in a few days will mean cool temperatures for the Northeast about one week later.

Typical highs for the middle of August in the Northeast range from the mid 70s in the northern reaches of New England to the upper 80s to the south near the Delmarva Peninsula and Chesapeake Bay. Overnight lows trend from the mid 50s at the top of New England to the low 70s along the Interstate 95 corridor and across the mid-Atlantic.

The current weather pattern likely feels even cooler on the heels of a July that saw the mercury hover about 2 to 4 degrees over the historical average for the Northeast. High humidity levels during this time period amplified the impacts of the heat.

How much cooler will it get for the Northeast? The upcoming forecast is predicting that both daytime highs and overnight lows will drop about 5 to 10 degrees below the norm for the last few weeks in August. The intermittent times of rain will bring the temperatures down even lower.

Meteorologists are also warning that the forecast atmospheric conditions will support the development of minor tropical weather features to come to life in the exceptionally warm waters of the Gulf Stream. Any tropical weather development, regardless of intensity, could bring down the mercury as well. For instance, the track of what is now Hurricane Ernesto in the Caribbean may spell cooler temperatures for the Northeast. The feature is expected to impact Newfoundland or Nova Scotia by the beginning of next week.

There is a strong chance that the jet stream will flatten by the end of the week. This would block the influx of cooler air from Canada and into the Northeast. The end result of this pattern would be that the warmer air circulating over Plains could push to the east and into the Northeast as the meteorological summer comes to an end.