[ADEQ Forecasts] Daily Air Quality Forecast for Saturday, August 22, 2009

[forecasts@lists.azdeq.gov]

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

For transportation alternatives:
http://www.valleymetro.org

Health message for Friday, August 21: Unusually Sensitive People should
consider limiting prolonged or heave exertion outdoors.

Health message for Saturday, August 22: No health impacts are expected.

Synopsis and Discussion
Forecast models are pulling back slightly on the amount of rain the
Phoenix forecast area will see this weekend.  Yesterday morning's run
caught some attention with, suggesting the possibility of storm totals
nearing 0.50-1.50 inches in some parts of the forecast area through
Sunday.  While a large moisture push from Mexico is still expected
Friday night into early Saturday (dew points soaring into the low to mid
60s), much of the rain will fall over desert locations to the south of
Phoenix.  Mostly cloudy conditions with a few passing showers and
thunderstorms can be expected for our area much of Saturday, and while
amounts exceeding an inch would be nice, it now does not appear to be in
the forecast.  The chance for showers will continue through Sunday
afternoon with a bit of drying by Sunday night.  More importantly, long
range models expect this Monsoon pattern (better late than never!) to
stay in place into the first week of September.

Thursday's air quality was very similar to that of Wednesday, with Queen
Valley again reaching the lower "Moderate" range (61 AQI) while all
other pollutants stayed in the "Good" category.  Blowing dust from
storms near Tucson and Casa Grande later this afternoon and evening may
impact the Phoenix forecast area, resulting in somewhat elevated PM-10
concentrations.  And even if we don't see widespread rain on Saturday,
the increased atmospheric moisture could be enough to weight the
suspended particles right out of the air by Sunday.  Thick cloud cover
Saturday will keep temperatures down (mid 90s) while prohibiting ozone
generation in the forecast area.  We're sticking with the forecast of
all pollutants in the "Good" range of the Air Quality Index (AQI) on
Saturday and Sunday.  

Check back on Sunday for the latest.  Until then, have a great weekend!


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


**********************************************************************
NOTICE: This e-mail (and any attachments) may contain PRIVILEGED OR CONFIDENTIAL information and is intended only for the use of the specific individual(s) to whom it is addressed. It may contain information that is privileged and confidential under state and federal law. This information may be used or disclosed only in accordance with law, and you may be subject to penalties under law for improper use or further disclosure of the information in this e-mail and its attachments. If you have received this e-mail in error, please immediately notify the person named above by reply e-mail, and then delete the original e-mail. Thank you.