The frozen, icy hellscape that rang in 2014 across the eastern United States returned for an encore in the west during the year's waning hours. Temperatures fell as low as -48°F in Wyoming this morning as a brutal cold snap brings strong winds, heavy snow, and even record high air pressure to areas west of the Plains.
At noon Central Time (11:00 AM Mountain), temperatures across a huge chunk of the country continued to hover in the teens or single digits, with much of the Intermountain West still solidly below zero. Wind chill values approached -50°F in many spots before sunrise this morning. This was the coldest December morning in the United States since December 23, 1998, according to Ryan Maue on Twitter.
The cold weather—not a result of the polar vortex!—locked into place across the west this week thanks to a very strong ridge of high pressure over the center of the United States. In fact, cold air helps to strengthen high pressure at the surface (because cold air is dense), turning the situation into a nasty feedback cycle of sorts.
Many areas set record high air pressure readings thanks to the cold weather this week. Seattle saw its all-time record high air pressure on Tuesday, with the barometer reading 1045.4 millibars at the air's highest density. Astoria, Oregon also set its all-time record high air pressure, clocking in at 1042.9 millibars on Tuesday. "Normal" air pressure at sea level is considered to be 1013.25 millibars.
Elsewhere, the cold is allowing wintry precipitation to fall as a result of a low pressure system moving through the southwestern part of the country. It briefly snowed this morning in Las Vegas, and higher elevations in California reported a coating of snow as precipitation came through during the overnight hours.
One to two feet of snow could fall in higher elevations across the southwest through Friday as the storm swings through, but the biggest threat to population center will be the ice.
Winter storm advisories and warnings are in effect for a huge part of Texas on Thursday and Friday in anticipation of a significant freezing rain event. Many parts of Texas will see ice accretions of one-tenth to one-quarter of an inch by Friday evening, which will make many roadways impassible without heavy treatment by crews.
The west will have a chance to warm up over the next seven days as the cold weather gradually confines itself to the Upper Midwest, Great Lakes, and Northeast.
[Images: Oklahoma Mesonet, WeatherBELL, NWS | UPDATE: The original headline/lede said -35°F, but the Weather Prediction Center has since updated the coldest low temp in the U.S. for Wednesday. The winner was Daniel, Wyoming, with a low of -48°F.]