A shape-shifting jet stream will drop temperatures across wide swaths of the United States amid warnings that cold weather could continue into spring.
Cooler than average temperatures threaten to grip Southern and Eastern states from President's Day weekend through the end of the month.
The mild heat will subside elsewhere as cool air from the north passes through Canada and the United States.
The shape of the jet stream will change from a “bulge,” which allowed a bubble of hot air to suffocate parts of the country, to a straighter “zone,” creating the change.
The jet stream will cause temperatures to drop
Weather channel
The tap will be turned off on the ongoing “atmospheric river” deluge that last week caused devastating floods throughout California.
“If you're looking for a change in the weather, you might be in luck,” said Linda Lam, a meteorologist with the Weather Channel.
“The upcoming change in pattern will bring an end to record warmth in the boreal and persistent wet weather in California.
“Temperatures will likely be cooler than average across much of the East and South on Presidents Day weekend and possibly the following week.”
The undulating jet stream will change the pattern of low and high pressure across the United States.
Near-record temperatures will give way to cooler winds although the Northeast and Midwest will remain milder than average.
The latest developments:
The south and east will be the most affected
Netweather
“The jet stream pattern will change by the second half of next week,” Ms Lam said. It will become more regional, moving generally from west to east. This will put an end to the high temperatures that are approaching record levels.”
This comes as parts of the United States prepare for another winter attack as winds and heavy rain move toward the East Coast.
Texas, New Mexico and Oklahoma are on a snow alert in anticipation of a “major winter storm” to dump up to a foot of snow.
Low pressure sweeping across the region and knocking down moisture over the Texas Panhandle will bring heavy snow to the south.
The National Weather Service (NOAA) warned that the winter and Easter storms will intensify during the week.
“As the storm system reaches across the mid-Atlantic region, concern will once again shift to a threat of significant winter weather as moisture begins to flow northward before the strengthening low center begins to encounter sufficient levels of cold air,” a spokesperson said.
“Locally, up to six to 12 inches of snow can be expected north of this low track. Strong winds and coastal flooding will also accompany this developing threat.”
A nor'easter is usually driven along the East Coast of the United States by winds from the northeast.
It usually occurs between Georgia and New Jersey, and increases in intensity when it hits New England.
New York and northern Pennsylvania will be at the front of the firing line early in the week before the storm heads toward New England.
“The main corridor of heavy snow is expected to form across northern Pennsylvania and southern New York before heading into southern New England on Tuesday as a very low central ledge offshore,” a NOAA spokesperson said.
“Locally, up to six to 12 inches of snow can be expected north of this low track. Strong winds and coastal flooding will also accompany this developing threat.”
