Rare nor'easter could bring lingering taste of fall

Tumbling temperatures this weekend could be here to stay. Canadian air, combined with a rare nor'easter could keep it feeling like September in the Northeast into next week.

Cities like Philadelphia and New York City were running 4-5 degrees above normal for the start of the month and reaching the 90-degree mark more than a handful of days. Philadelphia residents endured a longer stretch of hot conditions, where the persistent heat resulted in a 10-day heat wave. Boston's heat wave finally came to an end earlier this week after the city reached at least 95 F for six days in a row. During this stretch, the city set new daily record highs on four of the six days as temperatures fell just shy of triple digits.

Thanks to a new air mass moving southward from Canada, temperatures throughout this weekend in much of the Northeast are expected to be noticeably lower than during the first two weeks of August.

Temperatures took a nosedive across the interior Northeast on Saturday morning. Cities like Rochester, N.Y. and Pittsburgh dropped down to around 50 degrees, the lowest temperature recorded since early June and temperatures more akin to late-September. Some areas in Pennsylvania and New York even dropped down into the 40s for a couple hours Saturday morning.

Through early week, the fall-like conditions are expected to persist, with much of the region forecast to have high temperatures in the lower and middle 70s to the lower 80s.

Even more noticeable than the cooler air is the lack of humidity throughout the weekend. Dew points were commonly reaching the upper 60s and lower 70s earlier in the month, but are forecast to meander in the 50s, keeping it much more comfortable.

Dry weather is forecast to accompany the cool conditions for many through Sunday, although some showers are forecast to sneak into the Ohio Valley by Sunday afternoon.

More widespread wet weather is possible next week.

A storm developing across the mid-Atlantic on Monday will allow for showers across the southern half of the Northeast, and thunderstorms in cities like Washington, D.C. and Baltimore. High pressure is expected to keep northern New England dry on Monday.

AccuWeather meteorologists are monitoring where this storm could go as it moves off the coast into Tuesday.

"As the week progresses, the track and position of the storm will determine how wet it will get in New England, including in cities like Hartford, Conn., and Boston," said AccuWeather Meteorologist Joseph Bauer. One likely possibility is for a nor'easter to develop off the coast.

A nor'easter is a type of large storm that is aptly named for the strong northeasterly winds they can produce. While these storms can bring some of the biggest impacts to the beaches of the Northeast when they occur, they are also often associated with a heavy helping of snow, based on the time of year that they are most common.

"Roughly 80 of nor'easters occur between the months of October and April, so to get one in August is not the norm," explained Bauer.

Bauer added that nor'easters can happen at any time of the year, but tendencies in the jet stream during the summer months make it more rare for them to occur in August.

If the storm transitions into a nor'easter, wet weather is likely in much of the region, especially from Connecticut and Rhode Island northward to Maine. The New England beaches could also experience minor coastal erosion from the persistent winds through the middle of the week.

Wet conditions would also bring increased cloud cover for the Northeast, bringing a delay to the return of widespread 80-degree days.

While this pattern would give residents and vacationers alike less time to get out and enjoy the outdoors during these last few weeks of summer, the region could really use the rain.

Much of the Northeast has been abnormally dry as of late, according to the U.S. Drought Monitor. As a whole, New England has been the hardest hit, with areas from eastern Connecticut to southern Maine in a severe drought. Portland, Maine, has reported less than 50 of their normal rainfall since the beginning of June.

Portions of Rhode Island and Massachusetts are in an extreme drought, including the Greater Boston area. Since June 1, Boston has only recorded 3.21 inches of rain, more than 5 inches less than normal for the summer.

While meteorologists think it is less likely at this time, the storm could continue on a more easterly trajectory, and end up missing New England. Should this happen, more opportunities for wet weather are likely through the middle of the month. Many places across the Northeast are also forecast to escape the 90-degree temperatures during this time.

Released earlier this month, AccuWeather's long-range forecasters explained in the AccuWeather Fall Forecast that warmer-than-normal conditions will eventually return, and persist, through much of September.