End of Northeast, Midwest Heat Wave in Sight

By Alex Sosnowski, Expert Senior Meteorologist

July 17,2013; 9:12PM,EDT

 

 

 

An end to the heat wave is coming to the Northeast and Midwest this weekend.
The atmospheric heat pump will continue to run at full steam this week. However, folks suffering in urban areas or with limited means to keep cool will catch a break.
Actual high temperatures in most areas will continue to be in the 90s through Friday. AccuWeather.com RealFeel® temperatures will be 10 to 20 degrees higher.

Changes taking place this weekend will end the extreme heat. The pattern change should also take an edge off the humidity for a couple of days.

The high pressure system responsible for driving the heat will shift westward, allowing a cool front to make progress to the east and south.
Within a day or two of the frontal passage, thunderstorms will become more widespread with the likelihood of severe weather in some locations.
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Over the weekend, progressively less-extreme temperatures are forecast with the most noticeable drop in humidity around the Great Lakes, the interior Northeast and neighboring Canada.
The heat wave will continue Saturday over much of the mid-Atlantic and in coastal New England, before being broken Sunday.

City, State	Sat.	Sun.
Boston	91	77
Hartford, Conn.	92	83
Providence, R.I.	91	84
Albany, N.Y.	87	81
New York	98	84
Trenton, N.J.	91	86
Philadelphia	94	87
Pittsburgh	84	78
Detroit	83	76
Chicago	83	76
Cleveland	81	75
Indianapolis	86	78
Louisville, Ky.	88	85
Charleston, W.Va.	88	82
Nashville, Tenn.	91	88
Dover, Del.	91	88
Baltimore	92	87
Washington	94	88
Richmond, Va.	96	93

Because of the warm waters of the Atlantic Ocean this time of year, the advance of much cooler, less humid air from the northwest may slow to a crawl and could stall over the Tennessee Valley and the southern part of mid-Atlantic. The warm ocean water sometimes acts as a natural barrier for frontal passages during July and August.
Despite this, over Virginia, the Delmarva Peninsula and over the Tennessee Valley, for example, 90- to 95-degree temperatures and high humidity are likely to be replaced with 80- to 85-degree temperatures and moderate humidity for a few days.
If the front were to move along a bit more, then the cooling and the drop in humidity could be more pronounced farther south and right along the coast.
Beyond the weekend, humidity levels are likely to creep back up throughout the region and the pattern of frequent showers and thunderstorms could soon follow.
At this stage, it does not appear that extreme temperatures will be in a hurry to build back and stay for an extended period like it did during this week in the Northeast and in much of the Midwest.