The clock is ticking on the weather pattern that has delivered cold and snow in parts of the midwestern and northeastern United States during early April.
Waves of arctic air and rounds of snow have been ongoing since the start of April and will continue into the second week of the month.
However, a change in the weather pattern is on the way and one that warm weather fans might enjoy.
This weekend will be the last featuring widespread cold with snow across the Midwest and Northeast.
"The atmospheric traffic jam, which allowed the polar vortex to dip southward toward Hudson Bay, Canada, will break down," according to AccuWeather Senior Meteorologist Brett Anderson.
"A westerly flow of air from the Pacific Ocean will expand into the Eastern states and will allow temperatures to trend to more average levels for this time of the year beginning next week," Anderson said.
The new weather pattern will prevent arctic air from moving southward beyond northern Canada.
A taste of mild air will sweep from the Plains to the Ohio Valley and mid-Atlantic later this weekend into early next week.
The warmup will last about two days with highs well into the 50s and 60s F in many locations. Highs will be in the 40s to lower 50s from the upper Great Lakes to northern New England.
"One last piece of arctic air will drop southward across Canada during the middle of next week," according to AccuWeather Lead Long-Range Meteorologist Paul Pastelok. "However, the core of that arctic air will not plunge as far into the U.S. as those earlier this month."
"It could get cold enough for frost as far south as Virginia around April 13-14," Pastelok stated. "People should hold off a bit longer before planting or putting out tender flowers and vegetables."
During early next week and around the third weekend of April and beyond, temperatures most days will average within a few degrees of normal, with few exceptions.
By the third week in April, normal high temperatures range from near 60 in Minneapolis, Chicago and New York City to the middle 60s in Cincinnati, Philadelphia and Washington, D.C.
Anderson cautioned that brief episodes of cool and cloudy conditions can still occur well into April and May.
"Back door cool fronts are a notorious problem for areas along the Atlantic coast well into the spring," Anderson said.
For example, since New England is surrounded by water on two sides, normal temperature lag behind much of the rest of the nation. The ocean warms and cools more slowly than the land. The average high is in the middle 50s in Boston during the third week of April.
Another way for a few random chilly days to occur is for a storm to form in place and stall. Chilly storms of this nature in April and May are often surrounded by warm air and challenging to predict beyond a few days in advance.
AccuWeather Chief Meteorologist Elliot Abrams summed up the upcoming weather for the Midwest and East into May.
"While there will be some bumps along the way, and we do not expect any heat waves, the weather during from the second half of April and into May should be more typical of the time of year," Abrams said.