Return of the Summer

For the next week or so, the eastern half of the United States will be under the influence of a large, persistent downstream ridge. Part of this jet stream kink was forced by the disruption of Irma. As a deep deep trough settles into the west, the adjacent downstream ridge will build today and peak by Thursday of next week before beginning a slow retreat. The forecast highs for the Chicago area today look to approach 90!:

Nationally, a stark contrast between a warm east and a muchhhhh cooler west (Phoenix in the low 90s???) is apparent on the afternoon temperature map:

The summer-like weather will continue into next week (with a brief cooldown Monday with the passage of a potent cold front. By Thursday of next week, daytime highs could be approaching 90 again with nighttime lows not dropping much below 70 (it's summer again!) Here's a look at the massive dome of high pressure and respective temperature anomalies (departure from average):

Don't take those window AC's out for the winter yet!!