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.
A system with rain and thunderstorms will bring both good and bad news to the western United States later this week.
With the return of wet weather in the Northeast, many people are asking: When will the rain go away?
A change in the weather pattern will bring an extended period of dry and sunny conditions over much of the south-central United States.
After England and Wales endured a cool end to April and an unsettled bank holiday, the warmest air so far this year is set to arrive late this week.
Some communities along the southern Atlantic Seaboard will be hit hard with thunderstorms into the middle of the week.
Anglers around the Great Lakes had an early start to steelhead fishing season this spring following a warmer-than-normal winter, and recent warming conditions have brought the season into full swing.
Eastern U.S. (1812)
May snowstorm swept from Philadelphia northeastward to Maine. Snow covered ground in New York City; 12" accumulated near Keene, New Hampshire, 9" fell at Waltham, Mass., near Boston.
Severe snowstorm: 33.8" in Havre (24.8 inches of which fell in 24 hours).
New Orleans, LA (1978)
Persistent thunderstorms caused worst flooding in 30 years at New Orleans; lightning ignited an oil storage tank at Covent, LA.