Dramatic changes in the weather will occur across the eastern U.S. through the end of October. First, episodes of warmth and rain are in store, before colder air and localized snow showers arrive.
Following a sunny weekend in the Northeast, an episode or two of rain will affect part of the region during the first part of next week. Much of the rain during the early-week event may fall in areas where it is needed most, including across upstate New York and New England. A heavier round of rain will follow ahead of colder weather.
In the Matthew-ravaged Southeastern states, mainly dry weather will hold from this weekend through the middle of next week. Most days during this period will be sunny.
During the second half of the month, the jet stream will make some dramatic shifts, which are not uncommon for the time of the year, according to AccuWeather Lead Long-Range Meteorologist Paul Pastelok.
The jet stream is a fast river of air high in the atmosphere that guides weather systems along.
In much of the Eastern states, warmth will build during next week as the jet stream bulges northward.
Daytime temperatures will reach the 80s F in parts of the Ohio Valley, South and the mid-Atlantic. A few locations could even flirt with record highs. Farther north, highs will be in the 70s on multiple days from the Great Lakes to New England.
However, the jet stream will plunge southward late next week. Much colder air will flow from Canada as a result.
"While the timing, extent and magnitude of the cold air is uncertain at this point, enough cold air is possible allow the first snow showers of the season around the Great Lakes and perhaps into the central and northern Appalachians centered around next weekend," Pastelok said.
The anticipated cold push may bring daytime highs in the lower 40s to the lower 50s over a broad area of the Midwest and interior Northeast during part of the fourth week of October.
"We do not see any one pattern, including cold and snow locking in just yet," Pastelok said.
"Expect more swings in temperature and weather conditions into early November, or typical autumn mood swings for much of the eastern half of the nation," Pastelok said.
Preceding this change to chilly and snowy conditions for some may be a dose of heavy rain.
A slug of heavy rain would first develop over the lower Mississippi and Ohio valleys then move eastward late next week and into the weekend.
"There is a chance that tropical moisture could be drawn in, which could greatly enhance the rainfall in some locations," Pastelok said.
Any potential for heavy rain in coastal areas of the Southeast will remain a concern in the coming weeks. Some rivers in the region will still be above flood stage. It would not take an exorbitant amount of rain to renew flooding, due to the saturated state of the ground and high water levels on the streams and rivers.
Areas farther west in the South and farther north in New England could benefit by a dose of soaking rain, due to the long-term drought conditions. However, even in those areas there could be a tough travel day due to poor visibility and excessive water on the roads and low cloud ceilings at area airports.
AccuWeather will continue to provide updates on the upcoming warmth, rain and possible snow in the weeks ahead.