While astronomical autumn doesn't begin until Wednesday, Sept. 23, many in the eastern United States got an early taste of it this past weekend.
A dip in the jet stream sent damp and chilly air across the East on Saturday, dropping high temperatures down into the 60s from Minnesota to New York and as far south as Tennessee.
Overnight low temperatures dropped below freezing for the first time since the spring in some locations across Michigan and Wisconsin. For many, the air had an October-like feel to it.
The chilly air will not stick around for too long as a pattern change is expected this week across the eastern United States. The dip in the jet stream will completely flip into a ridge this week, allowing warmer air to build in.
"Above-normal warmth will make a return to the East this week, with daily high temperatures averaging 5 F to 15 F higher than normal," said AccuWeather Meteorologist Ben Noll.
Folks in the Plains to the Upper Midwest will experience the warmup early this week, while temperatures will slowly rise farther east across the Ohio and Tennessee valleys and Northeast through the middle of the week.
Cities such as Kansas City, Minneapolis, Chicago, Indianapolis, Detroit, Pittsburgh, and Nashville will have highs in the 60s and 70s be replaced with highs in the 80s.
The I-95 corridor from Washington, D.C., to Boston will also trend upwards in temperature towards the middle of the week. Thermometers will reach back into the mid to upper 80s in New York City by Wednesday.
Those who dug out jackets and sweatshirts this past weekend will still want to keep them handy as overnight temperatures will still dip to chilly levels, especially in outlying areas.
The surge of warmer air will not have too much of a summer feel to it due to limited moisture connection. This means humidity levels will remain at overall comfortable levels.
High pressure will not only bring an increase in temperature but it will also keep rain and clouds away for much of the week. It will be a great week to head outside for softball and baseball games, walks, bike rides, and picnics.
While some will see the dry and warm weather as a positive in terms of outdoor activities, it unfortunately means no relief from the abnormally dry conditions across the Northeast.
According to the U.S. Drought Monitor, around 48 percent of the Northeast is experiencing a moderate drought or abnormally dry conditions.
These conditions could worsen through the rest of the month if this overall pattern holds, which is a possibility. That kind of pattern will favor cool and wet conditions in parts of the West.
"While the warmth may be interrupted for a time next weekend or early in the following due to a passage of a cold front, it will quickly rebound in the latter stages of September," said Noll.
Noll also noted that the most substantial warmth will likely be found in the Plains and Midwest to round out the month.