[ADEQ Forecasts] ADEQ AIR QUALITY FORECAST FOR TUESDAY, DECEMBER 02, 2008

[forecasts@lists.azdeq.gov]

http://www.azdeq.gov/ensemble.pdf

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

Health message for Monday December 01: Unusually sensitive people should
consider reducing prolonged or heavy exertion.

Health message for Tuesday December 02: Unusually sensitive people
should consider reducing prolonged or heavy exertion.
 
Synopsis and Discussion
A 6:30 a.m. local ACARS sounding revealed that the best mixing depth
over the Valley today will only be near 2200' and that dispersion will
again be POOR to MARGINAL.  In addition, a strong (6-7 deg C) surface
based radiation inversion that formed overnight reached beyond 2500' for
only the second time this season.  These factors, in combination with
high near-surface humidity and elevated fine particle (PM-2.5) levels,
have resulted in a very dense Valley Brown Cloud that will likely be
slow to abate.  The very strong ridge aloft positioned just west of AZ
will weaken some on Tuesday as a weak disturbance moves southeastward
thru its position.  Increasing gradients aloft over the local forecast
area may impart enough momentum to produce a modest increase in surface
winds and dispersion tomorrow despite increasing afternoon high clouds.
A return to light winds is then expected to occur on Wednesday, at which
time fine particle levels may approach unhealthy levels; a PM-10 Health
Watch is possible for that day. -Reith  

**********************************************************************
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.