[ADEQ Forecasts] ADEQ Daily Air Quality Forecast - Thursday, March 01, 2012

[forecasts@lists.azdeq.gov]

Health message for Wednesday February 29:  No health impacts are expected. 

Health message for Thursday March 01:  Unusually sensitive people should consider reducing prolonged or heavy exertion outdoors. 
 

Synopsis and Discussion
PARTICLES:   Another mostly dry upper level trough and surface cold front in the mid-latitude storm track will move over Arizona from the northwest Thursday and early Friday.  This will result in an increase in winds in the Phoenix metro area mainly on Thursday but at this time little if any blowing dust is expected - perhaps just enough to raise 
PM-10 (coarse particle) levels into the low-moderate range of the Air Quality Index.  On Saturday a strong ridge aloft will begin to build overhead from the west and due to the accompanying  rapid warming aloft, relatively light winds, and overnight inversion formation, a significant increase in air mass stagnation is expected over the Valley by late in the weekend and beyond - especially during the morning hours.  
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 increased from 39.4 deg to 49.3 deg and day-length increased from 10 hrs 34 min to 11hrs 30 min.  Between Mar 01 and Apr 01 2012 the peak sun elevation angle will increase from 49.3 deg to 61.4 deg and day-length will increase 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