[ADEQ Forecasts] ADEQ Daily Air Quality Forecast - Wednesday, February, 15, 2012

[forecasts@lists.azdeq.gov]

Health message for Tuesday February 14: No health impacts are expected.

Health message for Wednesday February 15: No health impacts are expected.  


Synopsis and Discussion
PARTICLES:  The southern branch of the mid-latitude storm track is forecast to steer a pair of upper level troughs and surface cold fronts over Arizona this week - one today and another on Thursday.  Little or no rainfall has occurred over the metro area thru 10:00 a.m. today but additional showers are possible this afternoon.  The latter system is currently projected to follow a track to the south and west of the Phoenix metro area with just an outside chance for showers and no significant winds or blowing dust.  At this time 24-hour average PM-10 concentrations and unhealthy risk levels are forecast to continue in the low category. 
OZONE:  Although Valley ozone precursor (NOx & VOC) emissions tend to remain fairly constant all year, it is the increase in those factors conducive to efficient ozone production - such as peak sun elevation angle, day-length, and excessive heat - that will soon begin to contribute to an increase in local ozone levels.  For instance, between Feb 01 and Mar 01 2012 the peak sun elevation angle over the Phoenix area increases from 39.4 deg to 49.3 deg and day-length increases from 10 hrs 34 min to 11hrs 30 min.  Between Mar 01 and Apr 01 2012 the peak sun elevation angle increases from 49.3 deg to 61.4 deg and day-length increases from 11hrs 30 min to 12 hrs 34 min.     


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:

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