Chilly air is on the move and will deliver some of the lowest temperatures of the season so far to the New York metropolitan area by the weekend.
The second and stronger of two cold fronts will reach the Atlantic coast during the day Friday.
In its wake follows an area of high pressure that had its origins over the Alaska North Slope.
Under clear skies, in dry air and diminishing wind, temperatures will stop above 40 degrees in most urban areas Friday night into Saturday morning. However, lows in the 30s are likely in many suburban locations.
Temperatures will dip low enough to allow the formation of frost in the coldest locations outside of the city. This not only includes portions of northern and central New Jersey, the lower Hudson Valley and Connecticut, but also central Long Island.
If you have pepper or tomato plants still bearing fruit, you may want to harvest these items or risk losing them. Annual flowers should be covered or brought indoors if they are potted.
Rooftop or ground-level neighborhood gardens in urban areas should survive without damage during this event as warmth given off from buildings and pavement should keep temperatures higher.
Remember that official temperatures are measured at a height of approximately 6 feet above the ground. Temperatures nearest the ground in grassy, open areas of the countryside can be much lower, hence the danger of a killing frost or freeze in this event.
After a bright, crisp autumn day Saturday, temperatures will rebound to well-above seasonable levels Sunday through much of next week.
As the region turns chilly to start the weekend, violent weather is forecast to erupt over the Central States.
Hurricane Ignacio may enhance showers and stir rough surf for the Hawaiian Islands as it approaches next week.
After Erika brings heavy rain and locally gusty winds from Hispaniola eastern Cuba into Friday night, the system will move toward the Bahamas, the Keys and South Florida this weekend.
As many as seven tropical cyclones were churning throughout the world this past week, while smoke from wildfires across the Pacific Northwest led to poor air quality across the region.
Heat and humidity will return to Harrisburg this weekend and hang on into next week.
Heat will linger in Eastern Europe for much of the fall season; meanwhile, the British Isles and northwestern Europe can expect a stormy end to the season.
As Hurricane Katrina barreled towards the Gulf Coast, peaking at Category 5 strength while feasting on the warm waters of the Gulf of Mexico, meteorologists around the country prepared to deliver one of the most crucial and life-saving forecasts in history.
Pittsburgh, PA (1982)
39 degrees, coldest ever in August.
Anchorage, AK (1989)
A total of 9.6 inches of rain -- wettest August on record.
New England (1816)
"Year in which there was no summer", otherwise known to weather historians as "1800 and frozen to death" killing frost once again damages sparse corn corp in northern New England...loss of this and other crops led to severe famine in much of New England that winter...and helped spur western migration in spring of 1817.