Snow to Blanket Parts of Deep Southern Texas and Mexico Before Some U.S. Midwest, Northeast Cities See Season's First Snow
Published: December 7, 2017
Snow will blanket parts of northern Mexico through Friday, giving areas south of the border the first snow of the season before some cities in the U.S. Midwest and Northeast. Snow may dip as far south as Brownsville, Texas, as the cold air drops south.
(MORE: Winter Storm Central)
Cold air has already plunged down the Plains, crossing the Rio Grande River into northern Mexico. A reinforcing blast of cold air is just now arriving.
Current Radar and Conditions
(INTERACTIVE RADAR: Where the Snow is Now)
Widespread wintry conditions are occurring across south-central Texas, including in Austin and San Antonio.
Snowfall of 1.9 inches and 1.3 inches has been reported in San Antonio and Austin, Texas, respectfully, but locally heavier totals have occurred in Texas hill country.
Further west, more than six inches of snow was reported near Alpine, Texas on the mountain peaks. Most lower elevations in rural west Texas saw 2-4 inches.
Up to an inch of snow was measured in grassy areas in Brackettville, Texas, about 115 miles west of San Antonio, Thursday morning. Snow was also seen covering grassy areas in Eagle Pass, Texas, along the Rio Grande Valley between Del Rio and Laredo, and in the city of Laredo, which has reported light snow.
Parts of Mexico's border states, including Coahuila, have seen accumulating snow through Thursday afternoon:
Snow will gradually taper off in the Texas Big Bend, but is expected to develop into other parts of the Rio Grande Valley of Texas and southern Texas into early Friday.
Winter Weather Alerts
Incredibly, the National Weather Service in Brownsville, Texas has issued a winter storm warning for portions of interior deep south Texas and winter weather advisories for all of deep south Texas including Brownsville. Up to two inches of snow is expected in interior deep south Texas while the coast can expect a rain and snow mix with accumulations of less than a half of an inch.
Brownsville has only had one day of measurable snowfall on record.
The expected snowfall also prompted the National Weather Service office in Corpus Christi, Texas, to issue a winter storm warning for the central Texas coast including Corpus Christi and its first winter weather advisory in almost four years for a part of the Rio Grande Valley including the city of Laredo.
Winter storm warnings and winter weather advisories are also in effect for parts of west Texas, the western Texas Big Bend and for Texas hill country. Some areas of west Texas could see as much as five inches of snow, and travel could be dangerous in some areas.
Winter Weather Alerts
Snow will persist in northern Mexico's states of Chihuahua, northern Durango, Coahuila, northern Tamaulipas, and Nuevo León through early late Friday.
The heaviest snow accumulations, possibly up to a foot, are expected to be in the highest elevations of the Sierra Madre Oriental mountains in Coahuila state, with some accumulations over 6 inches also expected in the higher peaks of Chihuahua and Nuevo León, as well as the mountains in the Big Bend of Texas.
(CURRENT MAPS: Temperatures | Wind Chills | Fronts)
Rain and Snow Forecast
Some light accumulations are also possible in the city of Chihuahua – at an elevation of roughly 4,600 feet – though recent warmth makes it uncertain how much will be able to accumulate on paved surfaces.
A few wet flakes of snow also can't be ruled out in the city of Monterrey, even at a much lower elevation of around 1,700 feet. The mountains surrounding the city of over 1 million will likely see heavier snow totals.
This snow may also occur before some northern U.S. cities have seen their first snow of the season.
As of Dec. 6, Detroit and Pittsburgh had yet to record measurable snow this season. All typically do so by mid-November in an average year.
(MORE: When Winter Weather Conditions Typically Arrive Where You Live)
As that happens, a potent jet stream disturbance is now pushing over the region, providing lift and moisture in the atmosphere for precipitation in northern Mexico and West Texas.
Cold air is quickly surging southward into southern Texas and Mexico where rain will slowly change over to snow or a rain/snow mix.
The overall setup for snow in northern Mexico this week, featuring a plunge of the jet stream, providing atmospheric lift and moisture over cold air near the surface.
How Strange is This?
At first glance, the words "Mexico" and "snow" don't appear to go together, but in fact, it's more common than you think.
(MORE: The 10 Most Shocking Cities It Has Snowed)
Temporary road closure on Durango-Villa Union highway in the village of Llano Grande and Palmito, Wednesday, March 9, 2016, Durango, Mexico.(Federal Police of Mexico)
In March 2016, an unusually deep plunge of the jet stream wrung out snow as far south as Guadalajara, Mexico, the first time it had been witnessed there since December 1997.
Chihuahua, one of Mexico's coldest cities, typically sees measurable snow a couple of times each winter, according to Weather Underground weather historian Christopher Burt.
This happened just a few days after New Year's Day 2013, Burt wrote, and also occurred during the bizarre South Texas Christmas 2004 snow event.
(MORE: Strangest Weather I've Seen in My Career)
Snow is even rarer still in Monterrey, Mexico, about 3,000 feet lower in elevation than Chihuahua, and roughly the same latitude as Miami.
However, an early-January 1967 storm produced an incredible 20 inches of snow in the city in just eight hours, with some drifts exceeding 3 feet.
In most winters, it's not uncommon to see the surrounding mountains of Mexico City covered in a thin blanket of snow at times.
However, there have been two instances of snow in Mexico City itself: during the aforementioned January 1967 storm, and also on March 5, 1940.
Jonathan Erdman is a senior meteorologist at weather.com and has been an incurable weather geek since a tornado narrowly missed his childhood home in Wisconsin at age 7. Follow him on Facebook and Twitter.
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