Friday, December 21, 2007

Air Quality Warning: Minneapolis, MN

Today, December 20, 2007 and tomorrow, December 21, 2007 are Air Alert Days in the Minneapolis-St. Paul region. Light winds overnight have limited pollutant dispersion, and humid conditions and fog have enhanced particle formation in the Twin Cities, resulting in high particle levels this morning. For the rest of the day, light southerly winds ahead of a low pressure system over the northern Rockies will transport additional pollutants and moisture into the Twin Cities. Therefore, AQI levels will be Unhealthy for Sensitive Groups. Tomorrow, light to moderate southerly winds ahead of an approaching low pressure system will continue to transport moisture and pollutants into the Twin Cities, keeping AQI levels Unhealthy for Sensitive Groups.

Saturday, a low pressure system will move through Minnesota, enhancing mixing and causing gusty winds to develop. These conditions will lower AQI levels to Moderate.

Sunday, moderate northwesterly winds behind the low pressure system will disperse pollutants in Minneapolis, lowering AQI levels to Good.

Monday, surface high pressure over the Twin Cities will lead to light winds in the Minneapolis-St. Paul area, allowing pollutants to build up and resulting in Moderate AQI levels.

Tuesday, surface high pressure northeast of the Twin Cities will cause southeasterly winds to develop. These winds will transport some pollutants into the region, keeping AQI levels Moderate.