ST. LOUIS – Nearly 100 million people awoke to dense fog on Thursday morning – almost a third of the U.S. population – thanks to a weather pattern that swept warmer temperatures across the nation’s midsection in the wake of last week’s deadly arctic blast.
Fog alerts stretched over 1,500 miles across 20 states from Missouri to New York and from North Dakota to as far south as Texas. A few Freezing Fog Advisories were in place for parts of the Texas and Oklahoma panhandle and northeast New Mexico.
“One sign of all this warm air flooding northward, especially if you live east of the Rockies, you’ve seen it: the fog. Central and eastern U.S. cities right now socked in, heavy fog, as the warm air is overriding the cool air right to the surface,” said FOX Weather Meteorologist Amy Freeze.
With fog and low clouds entrenched in the Midwest, the National Weather Service Office in St. Louis reported the city has gone nearly 90 hours without seeing the sun – last seen around 6 p.m. Tuesday. The NWS St. Louis joked the sun is considered “missing.”
Visibility has been 2 miles or less in St. Louis for all but 7 hours since Tuesday evening.
Chicago is another town stuck in the fog – just behind St. Louis with the amount of time socked in. By Thursday morning, Chicago had gone 25 hours out of 38 with visibility down to 2 miles or less.
At one point Thursday, the FAA issued a ground stop at Chicago O’Hare International Airport due to just 1/8 mile visibility in fog.
Visibility was down to just 300 feet in Cleveland, and 0.13 miles in St. Louis on Thursday morning, according to the FOX Forecast Center.
Dense Fog Advisories remained in place until midday.
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Visibility is expected to improve as rain is forecast to move through the area later on Thursday. But unfortunately, the sun won’t be shining for some time in St. Louis.
With continued clouds and mild temperatures, forecasters with the NWS in St. Louis said the Sun won’t likely make an appearance until next week.
Contributing to the fog is the warmup happening for 270 million Americans this week. This mild weather pattern is interacting with frigid ground leftover from last week’s deadly arctic outbreak.
“That fog is acting as a blanket … any sort of the heating that we get throughout the day, not so much from the Sun, but just from the mixing of the atmosphere, because that warmth is spread through the mid-levels, and then it mixes down at the surface,” FOX Weather Meteorologist Stephen Morgan said.
Across the U.S. above-average temperatures have spread from west to east throughout the week with the warmest temperatures forecast for Friday for cities like New York.
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Philadelphia and Washington could even reach the 60s on Friday.
Pittsburgh had a high of 25 degrees on Sunday; by Thursday, temperatures are forecast to climb into the mid-50s – a sharp 30-degree warmup in just five days.