[ADEQ Forecasts] ADEQ Daily Air Quality Forecast - Friday, July 22, 2011

Thu Jul 21 12:35:42 MST 2011

Health message for Thursday, July 21:  Unusually sensitive people should
consider reducing prolonged or heavy exertion outdoors. 

Health message for Friday, July 22:  Unusually sensitive people should
consider reducing prolonged or heavy exertion outdoors. 

Synopsis and Discussion
OZONE:  Afternoon gradient wind gusts of 25mph on Wednesday were highly
effective in keeping local ozone plume accumulation well below average
and the result was mostly good ozone readings.  Westerly winds within
the 5-10K' layer over the metro area are advertised to weaken some on
Friday and then take on a partial easterly component on Saturday.  With
minimal cloud cover expected, the combined effects of increased ozone
production and accumulation will likely mean an upward trend in ozone
levels within the next few days. 
PARTICLES:  Despite thunderstorm outflow boundary-generated dust and
hourly PM-10 concentrations in excess of 2,000ug/m3 at two monitoring
sites, no 24-hour exceedances occurred in the Valley on Wednesday.
Summer monsoon moisture will temporarily be on the decrease over and
near the Phoenix metro area today and Friday with the slight risk for
thunderstorms and their outflow boundaries coming to an end.  A
significant increase in moisture and the potential for widespread storms
will resume on Saturday and continue into next week.  As was the case on
Sunday, Monday, and Wednesday periods of dense blowing and/or
transported dust generated by convective storm outflow boundaries will
be possible - along with a moderate risk for unhealthy PM-10 levels.   

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If you have any questions or comments regarding this forecast please

Arizona Department of Environmental Quality
Office of Communications
1110 W. Washington St., Phoenix, AZ 85007
(602) 771-2215

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