October 21, 2012; 6:00 AM
An unseasonable late-October warm-up is in store for much of the eastern half of the country early next week.
A broad and strong area of high pressure will set up over the mid-Atlantic, allowing for mainly sunny skies and increased surface heating.
The warmth will be aided by a rise in the jet stream, which will settle just north of the high pressure. This will keep out cool storm systems from Canada that would otherwise bring temperatures down.
As a result, temperatures will rise significantly above average across Harrisburg tomorrow through Thursday.
The peak of the heating will come on Wednesday when afternoon highs climb into the middle 70s across Harrisburg. The average high temperature for the capital city next week is 62 degrees.
By the end of next week, this high pressure will push off into the Atlantic Ocean, allowing for a wetter, cooler pattern for next weekend.