[ADEQ Forecasts] ADEQ Daily Air Quality Forecast - Tuesday, September 13, 2011

[forecasts@lists.azdeq.gov]

Health message for Monday September 12:  Unusually sensitive people
should consider reducing prolonged or heavy exertion outdoors.

Health message for Tuesday September 13:  Unusually sensitive people
should consider reducing prolonged or heavy exertion outdoors. 
 

Synopsis and Discussion
OZONE:  A moist and unstable air mass will likely yield lots of
afternoon cloud cover the next two days, along with a strong potential
for thunderstorm outflow winds.  These factors should help to keep local
ozone production and accumulation well below average with highest Air
Quality Index values forecast to remain in the good range.  Wednesday
and especially Thursday could be much more problematic if daytime cloud
cover and winds both drop to near zero as currently projected. 
PARTICLES:  On Sunday evening another wind (up to 30 mph) and blowing
dust (visibilities as low as 3/4 mile) event occurred that produced
unhealthy levels of PM-10.  The highest hourly concentration was
1,462.9ug/m3 at the North Phoenix monitoring site at 7:00 p.m.  The
interaction of an upper level low moving east in the mid-latitude storm
track and ample summer monsoon moisture already in place will yield an
increased chance for significant thunderstorm activity in the Phoenix
metro area today and Tuesday followed by a drying trend and an end to
said activity by Thursday.  Accordingly, the increased risk for
unhealthy levels of PM-10 due to areas of dense blowing dust generated
by outflow boundaries will continue thru Tuesday. 


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