A record-breaking blizzard that brought parts of the Rocky Mountain west to a standstill over the weekend had a surprise buried in the layers of snow: dust from Mexico.
Scientists with the National Weather Service say dust from Mexico was deposited as far north as Boulder, Colorado during the storm.
"We had a low that was tracking across the state and it was bringing a lot of gusty winds from the southwest. You could see on the satellite imagery the dust being lofted," Sharon Sullivan, meteorologist at the NWS in Albuquerque told CNN.
The Albuquerque NWS team tweeted satellite images on Saturday showing the path the dust was traveling.
“The dust that was lofted this afternoon from the playas in Mexico … has now been transported all the way into Colorado,” they tweeted.
The dust that was lofted this afternoon from the playas in Mexico (hot pink on the satellite imagery) has now been transported all the way into Colorado! Fortunately, the dust seems to be above the surface, so no restrictions to visibility in NM. #nmwx pic.twitter.com/NsRd4dP5Eq— NWS Albuquerque (@NWSAlbuquerque) March 14, 2021
In response, the NWS team in Boulder shared an image from outside their office, showing the thin layer of brown dust in the snow.
Check it out! We received a few comments that people saw a brownish layer in the snow and we were able to capture a picture of it here at the office. This is actually a layer of dust transported from Mexico! @NWSAlbuquerque pointed it out on satellite last night. #COwx https://t.co/XOTm74f87c pic.twitter.com/c5rdlyMRiR— NWS Boulder (@NWSBoulder) March 15, 2021
“We received a few comments that people saw a brownish layer in the snow and we were able to capture a picture of it here at the office. This is actually a layer of dust transported from Mexico,” they tweeted with the photo.
Winds had been gusting out of the southwest up to 70mph in parts of Colorado ahead of the storm, helping to carry the small particles of sand roughly 800 miles.
"The dust particles cling to the snowflake or water particle and falls with the snowflake to the ground," said Sullivan.
The phenomenon is similar to dust clouds that travel from the Sahara in Northern Africa across the Atlantic Ocean to Florida and Gulf of Mexico.