The TCEQ informs the public a day in advance when conditions are
forecast to be favorable for high ozone levels in any of nine
metropolitan areas so citizens, businesses, and industry can take
steps to reduce the pollutants that
contribute to ozone formation.
Program Background
What is an Ozone Forecast?
Ozone forecasts are made daily during the ozone forecast season
for each of nine metropolitan areas. Each
forecast is a simple yes or no prediction for the question, Will
ozone levels reach or exceed a target level for a particular
area?
TCEQ meteorologists use a set of criteria from historic
meteorological data, ozone measurements, and ozone prediction
models to make these predictions.
When they forecast an Ozone Action Day, the meteorologists
contact the National Weather Service, which then broadcasts the
information across its weather wire.
The agency also contacts officials in the affected area, and
that community's clean air coalitions notify local media,
government, business, and industry.
The forecasts are made, in most cases, a day in advance by 2
p.m. local time and are valid for the next day. The only exception
is for the Houston area, where the forecast can be updated as late
as 9 a.m. local time on the same day that the forecast is in
effect. The forecast target level for all areas is the U.S. EPA Air
Quality Index (AQI) Level Orange, which corresponds to an 8-hour
average of 76 ppb or a 1-hour average of 125 ppb. In the Houston
and Dallas-Fort Worth areas, forecasts for AQI Level Red may also
be issued and the target for these forecasts is an 8-hour average
of 96 ppb or a 1-hour average of 165 ppb.
The ozone forecast seasons do not necessarily correspond to the
"ozone seasons" defined for regulatory purposes by EPA (40 CFR Part
58 Appendix D, Table D3) and may differ.
Participating Metropolitan Areas
and Their Ozone forecast season Dates
Each day during ozone forecast season (roughly March through
November in Texas), the TCEQ forecasts ozone levels for nine
metropolitan areas:
|
Metropolitan Area |
Ozone Forecast Season Begins |
Ozone
Forecast Season Ends |
|
Austin |
April 1
|
October 31
|
|
Beaumont-Port Arthur |
May 1
|
October 31
|
|
Corpus Christi |
April 1
|
October 31
|
|
Dallas-Fort Worth |
May 1
|
October 31
|
| El
Paso-Juarez |
May 1
|
October 31
|
|
Houston-Galveston-Brazoria |
March 1
|
November 30
|
|
San Antonio |
April 1
|
October 31
|
|
Tyler-Longview-Marshall |
May 3
|
September 30
|
| Victoria |
May 1
|
September 30
|
