SIOUX FALLS, S.D. (KELO) -- It has been an active week for weather in parts of KELOLAND as low pressure systems have brought in big changes. From severe weather to winter storms, KELOLAND's Meteorologist Jaelyn Borresen takes a look at how we get these types of systems. This past weekend and again this week, low-pressure systems have impacted portions of KELOLAND leading to severe weather and blizzard warnings. Tree removal uprooting lots of emotions The two low-pressure systems that have passed through KELOLAND are called Colorado lows. These lows form when a strong trough dives over the Rocky Mountains and triggers lee cyclogenesis. This is when westerly flow with air descending on the eastern side of the mountains help initiate a low. The system then moves to the northeast and lasts several days as it travels through the Great Plains. The low gains strength as it meets clashing air masses. Warm, moist air from the Gulf of Mexico fuels cloud formation and heavy precipitation. When cold air is added from the north, it gets wrapped into the northern part of the low and creates heavy snowfall. Blizzard conditions often occur as the pressure gradient strengthens and the wind becomes strong. Additionally, severe weather can come into play as the cold front passes and helps create lift for thunderstorm development With Thursday being the first day of spring, the atmosphere will continue to be highly dynamic.. and while we get a break from the Colorado low, we will see a chance for an Alberta clipper to move in by the end of the weekend. ...read more read less