NM Border Air Quality Blog

April 4 - Morning cold front gave way winds in the morning and cooler temperatures.

Breezy north to northeast winds in the morning as a cold front slides over our region. The surface weather map at 9 am showed this with the stronger winds east of the Rio Grande. Note that the El Paso airport observed smoke this hour but it was actually dust from White Sands.

 

Dr. Tom Gill at UTEP emailed me this afternoon after he did some homework on the source of the haze in El Paso. Early in the morning winds from the front lofted dust from the dunes and advected them south along the Tularosa Basin and through El Paso. Below is a GOES visible image from 13:30 UTC (7:30 am MDT) showing the plume of white dust flowing south. I overlayed RTMA model prediction of winds at 7 am as the flow vectors.

The afternoon NWS forecast discussion at El Paso said

"A LOT OF LEE SLOPE AREAS SAW WIND GUSTS OVER 60 MPH SUNDAY WITH
THE PACIFIC COLD FRONTAL PASSAGE AND A RARE EVENT EVEN OCCURRED
OVERNIGHT FOR EL PASO AS THE A BACKDOOR FRONT MOVED IN FROM THE
NORTH NORTHEAST AND KEPT WINDS SUSTAINED OVER 20 MPH OVER THE
WHITE SANDS NATIONAL MONUMENT AND ADVECTED IN ITS WHITE DUST OVER
THE CITY RESTRICTING VSBY UNDER 7 MILES FOR A FEW HOURS OF THE
MORNING HOURS."

The Deming profiler also shows the cold front boundary nicely. It can be seen starting at 14 UTC this morning withe NE winds and was about 1 km deep.

A small wildfire was reported this morning west of Hatch on highway 26. Incident command noted it around 2,000 acres of grass burned. Winds were from northeast so the smoke mainly impacted areas far southwest of Hatch. Below shows the winds at 9 am from the Real-Time Mesoscale Analysis (RTMA) product with the location of the fire.

 

Monitoring stations on the east side of the region saw the impacts of the White Sands event in the morning. As expected the Chaparral station saw the highest hourly PM10 concentrations. Peak PM10 at Chaparral was 1456 µg/m3 at 6 am. The 24-hour PM10 concentration at Chaparral was 245 µg/m3 which was 163 percent over the EPA standard.

 

PM2.5 concentrations were also elevated during this event. Peak concentrations were similar at Anthony and Santa Teresa and about 10 µg/m3 high than at the Sunland Park Desert View station. The NMSU PM2.5 station also observed peak PM2.5 at the same time indicating that some of the dust might have migrated west across the Organ Mountains although impacts were very small at the Las Cruces East Mesa PM10 station.