South Texas Smoke March 28, 2008

• Backward Air Trajectory 28th 7:00 am CDT
• Backward Air Trajectory 28th 1:00 pm CDT
• Backward Air Trajectory 28th 7:00 pm CDT
• Satellite Image Gulf of Mexico 27th 5:09 pm CDT
• Satellite Image Gulf of Mexico 28th 9:09 am CDT
• Satellite Image Gulf of Mexico 28th 5:09 pm CDT
• Satellite Image Mexico 26th 2:40 pm CDT - Indicated Fires Red
• Satellite Image Mexico 27th 12:15 pm CDT - Indicated Fires Red
• Satellite Image Mexico 28th 2:25 am CDT - Indicated Fires Red

Smoke from agricultural burning in Mexico and Central America affected much of South Texas and southern portions of Central Texas on Friday March 28th.  

The highest daily average PM2.5 measurement during this event was 23.1 micrograms per cubic meter (µg/m³) at the Brownsville Continuous Ambient Monitoring Station (CAMS) 80.   This measurement rated as Moderate, on the U.S. Environmental Protection Agency (EPA) Air Quality Index (AQI) scale.   PM2.5 measurements were in the "Moderate" range at most of the PM2.5 monitoring sites in South Texas and in the San Antonio area.   The highest one-hour average PM2.5 measured was 34.8 µg/m³ at Laredo CAMS 313 from 9:00 to 10:00 p.m. Central Daylight Time (CDT). 

Backward air trajectories indicate that the air came from Mexico and Central America.   Satellite imagery also shows evidence of smoke in the western Gulf of Mexico on the 27th and 28th.   Fire channel satellite imagery shows numerous large fires in southeastern Mexico and Central America on the 26th, 27th, and 28th.