[ADEQ Forecasts] ADEQ Daily Air Quality Forecast - Thursday, May 24, 2012

[forecasts@lists.azdeq.gov]

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

Health message for Thursday May 24: Unusually sensitive people should consider reducing prolonged or heavy exertion outdoors.


Synopsis and Discussion
OZONE: As expected, the local ozone plume took a jog to the east on Tuesday but still managed to deliver unhealthy doses to several downwind sites. As of noon today hourly ozone concentrations ranged from 50 parts per billion at the Dysart monitoring site to 62ppb at Humboldt Mountain. These readings were 6 and 14ppb lower than 24 hours ago. Valley winds were already gusting to over 20 mph at 9:00 a.m. and will approach 30 mph during the afternoon today and Thursday due to the proximity of a developing trough in the mid-latitude storm track. As a result ozone levels are forecast to decline significantly during the next few days with highest concentrations confined to the far eastern metro area.

PARTICLES: The development of an unusually large but dry upper level trough over the western U.S. for this time of year will result in gusty gradient winds in the Phoenix metro area today with a slight decrease on Thursday. As the trough amplifies and approaches on Friday a prolonged period of strong and gusty winds now appears likely. There is currently an increased potential for not only periods of localized blowing dust but also for transported dust from Pinal County to overspread the area by late morning. For these reasons a PM-10 Health Watch may ultimately be issued for Friday.


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