What Causes Air Stagnation?
High pressure (dry weather) with light to calm winds for days on end, allow pollution to build up in the lower elevations. Valleys are most susceptible.
What is the Hazard?
STAGNANT AIR means poor air quality (unhealthy air) - this is not the best time to go for a jog and breathe it in. Each day the stale conditions persist, the pollution builds. Car exhaust, filling your gas tank, mowing your lawn can all contribute to the pollution build up. Those with breathing issues should stay indoors as much as possible.
today's air quality index is "moderate" check your area of the Inland NW and the Lewiston, Idaho live cam
URGENT - WEATHER MESSAGE NATIONAL WEATHER SERVICE SPOKANE WA
SUN NOV 24 2013
...AIR STAGNATION ADVISORY REMAINS IN EFFECT UNTIL 4 PM PST MONDAY... * AIR QUALITY: POLLUTION BUILD UP WILL BE POSSIBLE THROUGH MONDAY. * TIMING: THROUGH 4 PM PST MONDAY. LATE NIGHT AND EARLY MORNING PERIODS ARE THE MOST LIKELY PERIODS FOR UNHEALTHY AIR QUALITY. * IMPACTS: INCREASED POLLUTANTS COULD AGGRAVATE SENSITIVITY TO SMOKE AND OTHER PARTICULATES IN THE AIR. * WEB PAGE: FOR A DETAILED VIEW OF THE HAZARD AREA VISIT HTTP://WWW.WRH.NOAA.GOV/WRH/WHV/?WFO=OTX PRECAUTIONARY/PREPAREDNESS ACTIONS... 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 PHYSICIANS ADVICE FOR DEALING WITH HIGH LEVELS OF AIR POLLUTION.