HYSPLIT Migrates to the Cloud

July 26, 2021.

HYSPLIT was successfully moved to a cloud based hosting platform run by NOAA’s Web Operations Center at 10:16am on July 15, 2021, once testing was complete. This migration enables the NWS to have HYSPLIT access on an operational platform for 24/7/365 hosting and maintenance by reducing the probability of equipment failures.

NOAA’s Air Resources Laboratory developed the HYSPLIT model and enhancements that serve public health and safety as well as economic and ecological concerns. NOAA’s National Weather Service (NWS) is the primary operational user of HYSPLIT, and the NWS’s nationwide network of 120+ Weather Forecast Offices (WFOs) use HYSPLIT’s dispersion and trajectory guidance products on a daily basis to aid decision making in their local communities.

This migration ensures nationwide platform stability for the National Weather Service to use HYSPLIT in a variety of situations to forecast the atmospheric transport of smoke, hazardous chemicals, or other particulate matter. In a large-scale emergency, HYSPLIT runs are created at regular intervals and frequently updated in the event that a hazardous situation occurs. Immediate knowledge of a dispersion path can significantly improve response time, which can make a critical difference in lives saved.

During this migration, the operational code was also upgraded. Included in the new features are more geolocation tools, enabling users to input specific start points for a dispersion event without all the latitude-longitude information. A similar enhancement allows the source origin to be targeted via satellite imagery, such as storage tank, building, or railroad crossing. Lastly, the times are shown in local time rather than UTC, to enable readability and user interpretation.

HYSPLIT remains freely available to all users via ARL’s Real‐time Environmental Applications and Display sYstem (READY) web server, along with tutorials for a variety of forecasting operations.

Arial view of November 11, 2020 recycling plant fire in Houston, Texas. (Image courtesy of KHOU).

HYSPLIT Atmospheric Dispersion predictions for the Nov 11, 2020, northeast Houston area smoke plume shown at left. The WFO provided these information to the Houston Office of Emergency Management to inform the public alerts and response options.

What is HYSPLIT?

HYSPLIT is used to predict the transport of airborne smoke or chemicals during emergencies to properly target evacuations, and its value has been demonstrated in a range of emergency response situations. Accurate predictions of airborne particles during emergencies can significantly reduce the reaction time, cost and health burden on both residents and response agencies. HYSPLIT use continues to increase annually, a sign of its growing influence on emergency response to a broad range of human activities.

In a June 2021 case, the Chemtool plant fire in Rockton IL, the multi-day fire generated smoke, particulate matter and possible exposure to a range of chemicals used at the plant. HYSPLIT forecasts were provided by NOAA WFO’s every three hours to local officials; residents within a mile radius were ordered to evacuate at the height of the incident, while residents within three miles were recommended to wear masks outdoors. State, federal and local authorities responded for both the fire and the environmental impact assessment; costs and health impact assessments are ongoing.

Chemtool Plant Fire in Rockton, Illinois June 2021.