Snow Finally Comes to SAIL Site

Published: 25 January 2022

Editor’s note: Daniel Feldman, the principal investigator for the Surface Atmosphere Integrated Field Laboratory (SAIL) campaign in Colorado, provided the following blog post.

Snow covers ARM instruments and containers.
ARM Mobile Facility instruments and containers at Gothic, Colorado, are partially covered in snow in the midst of continued flurries with the late December 2021 snowfall. Photo is courtesy of Heath Powers, Los Alamos National Laboratory.

After an exceptionally low-snow fall of 2021 during the SAIL study at Gothic, there was a concern that the adage that the surest way to have strange weather patterns is to deploy a field campaign might be coming true. Gothic got no snow in September, 31 centimeters (12.2 inches) in October, and 30 centimeters (11.8 inches) in November. However, winter arrived in December! The snow finally began falling in earnest in the East River Watershed, where SAIL is focused, and hardly took a break until the new year.

With over 300 centimeters (118 inches) of snowfall in December at the main SAIL site in Gothic, there is now a good chance that the accumulation season will be in the normal range and not an extreme outlier.

Initial reports (here and here) indicate that an atmospheric river and a storm from Alaska combined upstream of the Colorado Rockies, both to deliver copious quantities of precipitation and to lead to above-average snowpack for the water year.

The snow dump provided an opportunity to study how these large-scale storms translate to powder on the ground through precipitation and wind processes.

This visualization of precipitable water vapor includes a legend from 0 to more than 70 mm.
This Integrated Data Viewer (IDV) visualization shows precipitable water vapor in visual relief and also color. The northern Great Plains are precipitation-free, but the Rockies are slammed by an atmospheric river. Data are from the National Centers for Environmental Prediction Global Forecast System (NCEP GFS), and the visualization is courtesy of Jeff Weber.

The SAIL campaign can use major meteorological events, such as the blast of precipitation at the end of 2021, to fulfill two of its science objectives: 1) establishing the relationships between precipitation in the SAIL study area and the large-scale circulation and 2) quantifying the importance of wind redistribution and sublimation to the snowpack.

These events also highlighted the literal hard work that is needed to collect data and make it available to the entire scientific community and beyond. Snow is heavy, doesn’t shovel itself, and can directly impact the ability of SAIL instruments to collect data, so a big thanks to the technicians for ensuring that the data continue to flow with minimal interruptions in spite of the subfreezing conditions. Both the science and logistics teams will be digging through this snowfall for some time to come.

2022 has started off not with a fizzle but a bang!

Read about how the SAIL campaign is teaming up with two other research efforts to better understand critical mountain hydrology.

Trees surround the Aerosol Observing System and X-band radar, with snow-covered mountains in the distance.
ARM’s Aerosol Observing System and Colorado State University’s X-band radar, deployed as a guest instrument for SAIL, operate at Crested Butte Mountain Resort on January 7, 2022. Photo is by Francesc Junyent, Colorado State University.