An outbreak of arctic air that will grow through the first half of Halloween week promises to send temperatures to their lowest levels since the spring across much of the U.S., with parts of every state except for Florida reaching the freezing point. And for many, the introduction to the cold air will be quick and abrupt with temperature drops of 10-20 degrees or more in just hours, if not minutes.
The FOX Forecast Center says the cold air invasion has already begun and will reach its maximum extent on Tuesday and Wednesday, as more than 200 million Americans feel the chill.
The cold air will mean wind chill values over the Northern Plains will drop to near zero degrees, and some communities that recently reached the 80s in the Northeast will struggle to climb into the 50s during the day next week.
“The coldest air of the season is creeping across the nation from the Northern Plains. Soon it’ll possess about 70% of the nation, at least below-average temperatures. All of this just in time for Halloween,” said FOX Weather meteorologist Ian Oliver.
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The cold air may be creeping, but it’s anything but subtle. The arctic front has been announcing its arrival with plummeting temperatures, erasing what had felt like misplaced summer weather and instead ushering in an early winter chill.
St. Louis basked in mid-80 degree heat on Friday, but the temperature dropped 23 degrees in two hours Friday evening as the cold front swept through, leaving the city in the mid 40s early Saturday morning on the way to a high of around 50.
Oklahoma City dropped 16 degrees in an hour from 73 to 57 Friday. Its forecast high for Sunday is 39. Dallas hit 88 on Friday but fell 16 degrees in three hours and will struggle to reach the upper 40s on Monday.
For areas to the east where the front had yet to reach Saturday, the abrupt chill was looming. Memphis was set to still reach 80 on Saturday, but its forecast high is just 65 on Sunday and 47 on Monday. Houston is set to plummet from a balmy 86 on Saturday and Sunday to a high of just 54 on Monday.
While many observation sites will miss out on setting records, forecast models show it will be commonplace to see temperatures 10 to 20 degrees or more below average.
Typically, during mid to late autumn, communities reach the mid-70s along the Gulf Coast, 60s in the Tennessee Valley and 50s around the Great Lakes.
With temperatures 10 to 20 degrees below average, a few record cold daily highs will be in danger of falling.
“Boston, you’re awfully close to the freezing mark as we move through the middle part of next week. Pittsburgh, you’re below freezing. Same story for places like Detroit. That’s as that cold air moves in behind that powerful front,” said Oliver.
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Communities in every state of the Lower 48 except in Florida have a chance of seeing morning lows deep below the freezing point.
Frost and freeze conditions will likely mean the ending of the growing season for much of the country as warm-weather crops face the potential for damage during the extreme weather.
And while the cold air will be a reminder that the winter season is not far away, the onslaught of the arctic air mass will not signal the country’s plunge into the season.
Forecast models show by the end of the week temperatures will rebound and flip to the majority of the country experiencing above-average temperatures.