Help Scientists Track Blowing Snow

Blowing snow can suddenly decrease visibility, making it a significant travel hazard. Photos courtesy Ed Szoke.

Few things are more beautiful than a sparkling layer of fresh snow transforming the landscape. But given a little wind, that snow can turn deadly. Lifted into the atmosphere, blowing snow can change a clear sunny day into a whiteout in minutes and that is a significant hazard for air and ground transportation and other outdoor activities. 

Meteorologists issue blizzard warnings when the conditions for blowing snow exist, but blowing snow events can be sudden and often take people by surprise. That’s why scientists like Bill Line are working to give forecasters more tools to track blowing snow. Line is a research scientist at the National Oceanic and Atmospheric Administration’s (NOAA) National Environmental Satellite, Data, and Information Service (NESDIS) in the Center for Satellite Applications and Research (STAR) where he is developing satellite-based data products that map the extent of blowing snow. The GLOBE community can help verify the satellite data by providing cloud observations that document the presence of blowing snow on otherwise clear days.

Tracking Blowing Snow

Blowing snow is snow that is either lifted from the ground and transported by strong winds or falling snow that is blown horizontally, both of which reduce visibility and impact transportation. Line’s satellite analysis studies snow lofte d from the surface on clear sky days, which makes it detectable in satellite imagery. This type of blowing snow can occur whenever loose snow is present on the ground and strong winds are able to lift it at least several feet above the surface. In contrast, drifting snow remains very near the surface and does not substantially obscure visibility.

Blowing snow in rural Iowa creates near white-out conditions. Photo courtesy National Weather Service Des Moines/Mahaska County EMA.

The challenge is that blowing snow is hard to see remotely. “Weather radar is designed to detect precipitation falling from clouds, and is not very sensitive to blowing snow near the surface,” says Line. Because blowing snow is made up of snow lifted from the ground rather than snow falling from the sky, it usually does not appear in radar imagery, even though it can still reduce visibility well above the ground.  Historically, the weather service has used observations from law enforcement, webcams, or the public to tell them that blowing snow is occurring. 

Now, next generation weather satellites in the GOES-R series (like GOES-19) and JPSS series (like NOAA-20) have enough resolution to detect blowing snow. By combining infrared and visible light, Line and his colleagues are able to highlight blowing snow in satellite images when skies are clear, but interpreting the images can be challenging. “Blowing snow detection using satellite imagery is very new so we are still learning about it,” says Line. “We need to know that what we are seeing in the satellite is actually blowing snow. That’s part of the research and continued refinement of this product.” 

Learn more about the blowing snow product in the JPSS VIIRS and GOES Blowing Snow Quick Guides. 

To verify satellite imagery of blowing snow, Line has tapped the network of transportation webcams maintained in many states and photos posted on social media. How do the photos help? “Often the satellite product shows this narrow plume producing blowing snow at the surface, so you might have visibility less than quarter of a mile in one area, and then one mile to the east, you might have perfect visibility,” says Line. “To be able to have photographs or observations of what is actually occurring underneath the plume is really important.”

 This satellite image from GOES-16 shows lines of snow blowing over a snow-covered landscape in North Dakota on January 18, 2022. The false-color image is made with a combination of visible and infrared light. Snow on the ground is dark red, while blowing snow is light orange. Land not covered in snow is bright green, clouds are turquoise.

A North Dakota Department of Transportation webcam captured the 18 January blowing snow event confirming the presence of blowing snow in the satellite data product. 

How you can help track blowing snow

Starting in December, you can help support Line’s work by submitting photos of blowing snow through the GLOBE Observer app. Data will be collected during this pilot project between December and February. 

To participate in the Blowing Snow Pilot:

• Open Clouds in the GLOBE Observer app
• Select “obscured skies,” then blowing snow if you see any blowing snow even if skies are otherwise clear
• Photograph the sky in the four cardinal directions and up and down as directed
• Photograph the horizon where blowing snow is visible and upload the photo as a special feature photo
• If possible, enter the distance to any visible landmark in the blowing snow photo to help scientists assess visibility

Detailed instructions for collecting blowing snow observations can be found on the blowing snow project page. 

Blowing snow conditions can be very dangerous. If it is not safe to go outside, the protocol may be done from a building or car. Please indicate that you are indoors in the field notes. 

All blowing snow photos are valuable, but photos taken during a NOAA-20 overpass are especially useful. Tap the satellite icon in the Clouds lower navigation bar to see when NOAA-20 will be over your location and to set an alert. 

Learn more about how to participate on the blowing snow project page. 

How your data will be used

All data collected during the blowing snow pilot will be pulled into a data dashboard to help scientists like Line access it quickly. The photos will be used to confirm the presence of blowing snow in satellite data. By improving the tools scientists have to detect blowing snow at your location, you are helping them create better products to help people everywhere. 

Learn more about Line’s work in this presentation:

 

This project was developed in collaboration with the National Oceanic and Atmospheric Administration’s (NOAA) National Environmental Satellite, Data, and Information Service (NESDIS), the Geographic Information Network of Alaska (GINA) at the University of Alaska Fairbanks, and the GLOBE Implementation Office Science, Training, Education, and Public Engagement team (STEPE) at City University of New York.

More >>

Comments