HYSPLIT Provides Seven Straight Days of Situational Awareness Following Explosion, Fire at Texas Plant

December 2019

One week after a series of explosions at a chemical plant in Port Neches, Texas, the resulting fire is still burning and ARL/ASMD’s HYSPLIT model is continuing to provide forecasters with crucial information regarding the transport, dispersion, and deposition of air pollutants. HYSPLIT simulations are based on weather conditions and are initiated by National Weather Service Weather Forecast Officers, who provide them to emergency planners and first responders charged with protecting life and property and mitigating environmental damage. Lake Charles, Louisiana, the closest regional office to Port Neches, initiated the HYSPLIT model runs, still taking place roughly every two hours, to assess the transport and dispersion of hazardous industrial materials.

A major explosion occurred in the early morning hours of Wednesday, November 27, rocking the small, southeast Texas city about 80 miles east of Houston and setting its chemical plant ablaze. A second explosion took place less than 13-hours later and the resulting potential for additional explosions led to the issuance of a mandatory evacuation order for the approximately 50,000 residents in a four-mile radius of the plant, along with a curfew period from 10 p.m. to 6 a.m. At one point nine fires burning at the site, combined with the loss of power, prevented emergency response personnel from investigating both the cause of the explosions and the extent of the damage. Emergency managers were initially concerned about the release of butadiene, a colorless gas produced at the site and considered to be a health hazard, and later feared asbestos contamination from exploded equipment containing asbestos insulation. After nearly 48 hours, the curfew was lifted and residents were able to return home, where they can rest assured that HYSPLIT is keeping tabs on plumes from the still-burning refinery.

HYSPLIT is a state‐of‐the‐art analytical tool initially developed by ARL over 30 years ago to produce operational and research‐grade dispersion products. Thanks to continual development and enhancements, HYSPLIT remains one of the most widely used models for atmospheric trajectory and dispersion calculations; successfully answering the fundamental questions: where did it come from, where is it going, and where is it hazardous?

ARL also developed the aptly named Real-time Environmental Applications and Display sYstem (READY) that gives HYSPLIT users outside access to ARL’s web server in real-time. Users can access and display meteorological data products and run the HYSPLIT model using forecast or archived meteorological data.

Map showing Houston, TX at left and Lake Charles, LA on right. Port Neches slightly right of center indicated by red +, with colored plume traveling northeast.
HYSPLIT simulation of one “generic” hazmat/industrial pollutant per cubic meter in a one-hour period on November 27, 2019.
Port Neches at left indicated by red + on a map showing the outline of counties in the general area. Four colors shown, indicating chemical dispersion > 1 hour to > 11 hours after the model was run.
HYSPLIT time of arrival plot for hazmat/industrial pollutant originating from the Port Neches, TX plant on December 1, 2019.