If you have lived in Erie for any length of time, you know how lake effect snow works. Snowfall amounts can vary widely from one location to another.
Lake effect is local and it all depends on exact wind direction and where the most intense lake effect snow bands are. That’s why spotter reports are so incredibly helpful.
There are also other tools that are used to determine a lake effect snow forecast.The most important tool is Doppler radar. But even Doppler radar can have trouble detecting lake effect snow in this part of Northwest, Pennsylvania. because of our location in between Cleveland and Buffalo.
“Well, radar is interesting because the earth isn’t flat, so we set these radars down at various air fields across the country. Because of the curvature of the earth, that radar beam where it is seeing the weather, if you will, above the ground quickly increases in height as the energy beam goes out into the atmosphere because of the curvature of the earth.” said Zach Sefcovic, meteorologist with National Weather Service Cleveland.
The radar beam that scans the skies over Erie was roughly about 10,000 feet above the surface. That is about 2 miles off the surface. Recently, the National Weather Service offices in Cleveland and Buffalo have implemented new technology that actually lowers the height of the radar beam, which makes it easier to sample lake effect snow over northwest Pennsylvania.
“Recently, we have undergone changes to our radar where we are able to lower the beam height of how the radar views the weather in the atmosphere.” Sefcovic said.
With the new changes to the radar, the beam height is now about 7,000 feet above the surface or about a mile to a mile and a half. It may not seem like a big deal, but when it comes to lake effect snow, it is huge! That is because lake effect snow is very shallow in the atmosphere and roughly occurs within a couple thousand feet above the surface.
“With the old radar strategy that we had, the beam over Erie was at 10,000 feet. There were times where the radar didn’t show anything was happening. Meanwhile, it is a raging snowstorm in Erie. So, by lowering, we can see a little bit more of that and, at least, have a better understanding that snow is actually happening without having to call someone or see what the Department of Transportation are doing or anything like that.” Sefcovic said.
While Doppler radar is arguably the most important tool we have when it comes to forecasting lake effect snow, there are other forms of remote sensing technology that can help verify what the radar is detecting and one of those tools is the GOES 16 satellite imagery. The GOES 16 satellite can detect whether or not there is ice in the cloud by using temperature.
If there is ice in the cloud, then it is a pretty good tip off that is probably snowing. The bottom line is there are multiple tools we use when it comes to forecasting lake effect snow and now that the radar beam has been lowered, it will help tremendously! The more we can see, the better off we will be when preparing you for the next lake effect snow event.