Quick surges of frigid and mild air will produce dramatic temperature swings from one day to the next in the East.
The temperature swings of 25 to 50 degrees in a matter of hours will make it very hard for some people adjust and can lead to melting and freezing cycles that cannot only rupture water mains but also cause ice to form following bouts of melting snow.
During the cold days, when the wind is blowing, combined with other atmosphere conditions, RealFeel® temperatures will be 10 to 30 degrees lower than the actual temperature.
Air blasted southward from eastern Canada on Friday night, sending temperatures down to some of their lowest levels since January 2009 in many locations from New England to part of the mid-Atlantic including, Boston, Hartford, Conn., and Scranton, Pa.
Lows bottomed out in the single digits Saturday morning from Pittsburgh to Baltimore and even dropped below zero farther north in places such as Scranton, Pa. and Albany, N.Y.
However, after a cold day on Saturday, temperatures will rebound to above-average levels from the Appalachians to the coastal mid-Atlantic and southern New England.
According to Long Range Weather Expert Paul Pastelok, "Temperatures will reach the 40s in Washington, D.C., Baltimore, Philadelphia and New York City on Sunday."
The warmup will not set a new trend.
Already Sunday, another blast of frigid air will be charging in across the Central states. This one will arrive from the west and will sweep across the Ohio and Tennessee valleys and into the Appalachians Sunday night in the wake of snow, a quick freeze and even a blizzard in some areas.
The new blast of frigid air will push over the Appalachians and to the Atlantic Seaboard during Monday.
"Temperatures Monday that start near mild levels in the 40s and even near 50 degrees in some locations will crash below freezing as the day wears on," Pastelok said.
Temperatures are forecast to plunge toward zero Monday night in the Appalachians and into the teens along the I-95 corridor. Temperatures may rise very little Tuesday, from the 8:00 a.m. lows.
Temperatures will start the day Monday and Tuesday below zero over much of the Ohio Valley and may rise to only the single digits.
"Around the western Great Lakes, such as Chicago, temperatures are likely to remain below zero around the clock on Monday," Pastelok added.
The last time temperatures were this low was during early February of 1996 in Chicago and vicinity.
As temperatures rise through the weekend in the South, so will the risk for heat-related dangers.
While heavy rainfall inundated the Phoenix area with historic flooding, deadly landslides occurred in Japan, claiming dozens of lives.
While a tropical low is expected to brew into Tropical Storm Cristobal this weekend, the East Coast of the U.S. is being monitored for future impacts -- even if the storm remains well offshore.
United States residents may pay higher heating costs this fall as colder air is expected to grip the Rockies and Plains at times and some quick-hitting chilly shots may impact the Northeast.
A swath of soaking rain will slowly shift from the northern Plains to the Canadian Prairies this weekend, making people reach for their umbrellas and heightening concerns for flooding.
While residents will face more disruptions to outdoor activities on Saturday, dry air will push southward across Pittsburgh to end the weekend.
Dallas/Ft. Worth, TX (1980)
105 degrees -- the 60th consecutive day with a high temperature of at least 100 degrees.
Lake Ontario (1987)
Strong northwesterly winds caused upwelling. On the south shore, the water temperature was 70 degrees, but along the north shore, it was only 41 degrees.
Heavy rains caused floods. Kilmarnock, VA, had a two-day total of 13.50 inches, and Nassawaddox, VA, had 12 inches.