Rain is set to soak the abnormally dry Northeast starting on Tuesday as a shot of noticeably cooler air arrives for the transition from September to October.
While this September could go down in history books as the warmest September on record in many cities across the Midwest and Northeast, the month will end with cool air blasting down from Canada.
The cool shot will bring a noticeable drop in temperatures to the Upper Midwest on Monday, the Great Lakes on Tuesday and then the Ohio Valley, New England and mid-Atlantic on Wednesday.
When the cool air arrives, it will cause temperatures in many places to be held about 10 to 15 degrees Fahrenheit below the previous day's high.
Highs in the 60s are expected from Minneapolis to Chicago to Detroit to Washington, D.C., New York City and Boston when the cool air is in place. New York City and Washington, D.C., have not had a high below 70 F since early June.
"Afternoon temperatures may only be in the 50s by Friday and this weekend [in parts of the Northeast], which will be a shock to residents given how warm it has been at times over the past couple of weeks," stated AccuWeather Meteorologist Brian Thompson. Late-week rain may also contribute to temperatures being held well below normal.
The cool weather may be just what trees need in the Midwest and Northeast to bring out their bright colors after recent warm weather slowed the onset of the fall foliage, where dry weather prevails.
The cold front opening the door for the cooler air to arrive will push through the Midwest early this week with a band of showers or a period of rain, causing some minor inconveniences to those with outdoor plans. Dry weather will quickly return for midweek.
However, the rain may be heavier in the Northeast and slower to depart.
As the front moves into the Northeast, tropical moisture will be drawn northward and cause steadier rain to develop Tuesday into Tuesday night.
AccuWeather meteorologists will be monitoring the potential for the rain to pour down heavy enough to cause incidents of flash flooding and/or heighten concerns for vehicles to hydroplane at highway speeds. Airline passengers may face flight delays.
The cold front is then expected to slow down and eventually stall as it reaches the western Atlantic Ocean. The result will be for a cool rain to slowly push offshore Wednesday into Thursday.
Depending on where the front settles offshore, some communities from the southern New England coast to the mid-Atlantic may see the rain persist all through the late week.
Regardless of any rain later in the week, the squeeze between the front and the cool Canadian area of high pressure will once again allow gusty northeasterly winds to buffet the New England and mid-Atlantic coasts, renewing the danger of rough surf, rip currents and coastal flooding after this weekend's lashing.
Toward the upcoming weekend, latest indications point toward a coastal storm possibly spinning up along the tail-end of the front. Such a solution would increase the winds at the coast and spread the cool rain across more of the Northeast.
Despite the headaches those with outdoor plans will likely face due to the rain on either side of the cold front, the upcoming wet weather has one positive aspect, according to Thompson.
"This rain would be beneficial for much of the Northeast, where it has been pretty dry of late," he said.
"Boston and New York have not had measurable rainfall in two weeks and both cities are running a seven-inch precipitation deficit compared to average this year."
The United States Drought Monitor reported last Thursday that 58 percent of the area from West Virginia and Maryland to Maine was at least abnormally dry.