[ADEQ Forecasts] ADEQ Daily Air Quality Forecast - Wednesday, May 23, 2012

[forecasts@lists.azdeq.gov]

Health message for Tuesday May 22: Unusually sensitive people should consider reducing prolonged or heavy exertion outdoors.

Health message for Wednesday May 23: Unusually sensitive people should consider reducing prolonged or heavy exertion outdoors.


Synopsis and Discussion
OZONE: More unhealthy ozone levels occurred on Monday but were these down in absolute concentrations and were mostly displaced to the east of the central metro area.  As of noon today hourly ozone concentrations ranged from 44 parts per billion at the Central Phoenix monitoring site to 76ppb at Humboldt Mountain.  These readings were -10 and +5ppb from those of 24 hours ago.  Hourly readings at those sites that exceeded on Monday ranged from 10ppb lower to 5ppb higher than 24 hours ago.  The evolving synoptic weather pattern is still seen as conducive to a downward trend in local ozone concentrations the remainder of the work week due to increasing afternoon winds and a decrease in afternoon high temperatures.  In addition, since there is currently no forecast model consensus on the potential for a significant influx of ozone and/or its precursors to the Valley the next few days, local ozone levels are forecast to drop into the mid-moderate range of the Air Quality Index by Wednesday.  By then the local wind regime should keep highest ozone levels confined to the far northeast and east Valley.  

PARTICLES: A strong ridge aloft will be over Arizona today but with enhanced breeziness by this afternoon.  The development of an unusually large upper level trough over the western U.S. for this time of year will result in gusty afternoon gradient winds in the Phoenix metro area Wednesday thru Friday along with the slight possibility for occasional blowing dust in some areas.  However, at this time the risk level for substantial blowing dust and high levels of PM-10 (coarse particles) is low.  


For more information, please visit our Web page:
www.azdeq.gov/environ/air/ozone/ensemble.pdf 

For transportation alternatives:
www.valleymetro.org 


If you have any questions or comments regarding this forecast please contact:

Mark Shaffer, Communications Director
Arizona Department of Environmental Quality
Office of Communications
1110 W. Washington St., Phoenix, AZ 85007
(602) 771-2215
ms15@azdeq.gov