A deep dive in the jet stream is forecast to send South Florida its first cold front next week, dropping overnight lows into the 60s and capping daytime highs in the upper 70s to low 80s.
The National Weather Service in Miami said this morning the front, which is attached to a low pressure system in the northwest part of the country, will clear South Florida Wednesday.
Behind it will be Canadian air that could bring snow to the Great Lakes.
“If this scenario comes to fruition, then South Florida could feel its first taste of fall, with some drier, cooler air,” forecasters wrote in their morning discussion.
While the NWS official forecast goes out only through Wednesday, AccuWeather is less shy when it comes to long-range forecasts, putting the daytime high a week from today at 81 degrees, with an overnight low of 66.
Dan Kottlowski, a senior meteorologist with AccuWeather, said the orientation and the strength of the jet stream is expected to force cold air deep enough for South Florida to feel the chill.
“We need (the jet stream) to dip down over northern Florida to really make a good surge,” Kottlowski said. “Next week, it dips down right over the north part of the state and we think that it will make much bigger progress.”
The plunge will push temperatures slightly below normal for late October. In West Palm Beach, the normal daytime high for Oct. 26 is 83 degrees, with a normal overnight low of 70.
While temperatures will drop next week in South Florida, the National Weather Service has yet to declare the start of the dry season.
The dry season usually begins between Oct. 12 and Oct. 19, but can be as early as the end of September or as late as early November.
Sometimes a strong cold front can signal the beginning of the dry season. Even hurricanes, such as Wilma in 2005, can bring in a punch of cold, dry air that kicks off the dry season.
The first cold front will be most welcome by South Florida, where above average temperatures were the norm this fall.