Passing on some notes from today (Sunday, Sept. 16, 2012) …
Currently, there is an air stagnation advisory issued by the National Weather Service for these counties through 5 p.m. Tuesday: Grant, Lincoln, Spokane, Adams, Whitman, and populated areas of Garfield and Asotin counties (not the elevated portion in the Blue Mountains).
According to the National Weather Service: “An air stagnation advisory indicates that due to limited movement of an air mass across the advisory area … pollution has the potential to increase to dangerous levels. Persons with respiratory illness should follow their physician’s advice for dealing with high levels of air pollution.”
According to Randall Ruddick in our Spokane office: “Asotin and portions of Spokane counties are in the Unhealthy category. I expect Spokane to improve to at least Unhealthy for Sensitive Groups.”
As of 7 a.m. today, air quality in the Wenatchee area was measured in the Hazardous category.
Here’s the morning forecast from Ecology forecaster Ranil Dhammapala:
Issued by Ranil Dhammapala, Washington State Dept. of Ecology
Air quality in most areas saw considerable improvement on Saturday. Clearing will continue through Sunday evening, but there could be areas in and around the Columbia Basin that experience smoke for a short time today.
A period of prolonged stagnation sets up through most of WA starting Monday, with winds being mainly terrain driven. Temperature inversions are expected to be strong but are forecast to break up during the day in most places. Yet with light and variable winds, pollutants will not disperse as well. While it is hard to pin down exact details for each community, in general most areas are likely to see air quality degraded to some extent. Communities close to smoldering fires are likely to be impacted throughout the day to varying degrees. Partial daytime clearing in most areas with the least clearing in sheltered valleys, seems to be a good bet.
Models are suggesting mildly offshore pressure gradients, which could push a little smoke over the Cascades into western WA over the next few days.