Elevated AQI in terms of PM2.5 were observed today across the Great Lakes, with Code Yellow (Moderate) and Code Orange (Unhealthy for Sensitive Groups) levels confined to Iowa and the Dakotas (top left). In addition, afternoon MODIS imagery from the Terra satellite indicated elevated AOD over a portion of the aforementioned region (top right). Blowing dust believed to have originated from Chihuahua, Texas was observed by the HMS analysis team to be moving into central and eastern Texas. PM2.5 levels also peaked at Code Orange (Unhealthy for Sensitive Groups) levels in this region today (bottom left). In addition, the SPC issued a Critical, Extreme and Extremely Critical Fire Weather outlook for the state, with the worst conditions in the lower Rio Grande Valley. Powerful northerly winds behind an offshore low pressure system have funneled an extremely dry air mass (relative humidity values less than 20%) southward making conditions favorable for fires to thrive and spread should an ignition occur (bottom right).
Posted by Alexandra St Pe at February 25, 2013 9:07 PM