May 18, 2012
Quiet weather pattern doesn't bode well for lingering smoke layers over Mid-West
As discussed over the past several days, smoke from the Siberian fires continues to affect the mid-section of the US. The smoke was observed today stretching from the Gulf through the Great Lakes, some of which is also originating from the plethora of wildfires in the Pacific Southwest (top left, courtesy HMS). The HMS team reports moderately dense smoke over Texas, which also reached Code Orange (Unhealthy for Sensitive Groups) PM2.5 levels this afternoon. In fact, air quality remained in the Code Yellow (Moderate) range in areas juxtaposed to smoke observations, climbing to Code Orange along the Mississippi coast and River Valley (top right, courtesy AIRNow). The relatively quiescent weather pattern over this part of the country is not helping to improve the air quality situation, as weak winds in the mid and upper troposphere limit smoke layer advancement (bottom left, courtesy NOAA). Unfortunately, the NAAPS models are forecasting the smoke to remain nearly stationary through the weekend (bottom right).
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