NOAA-NWS Analysis of Record (RTMA/URMA) Update and NWS Support to Air Resource Advisors
Media Type: Presentation
  • Ryan Leach
    National Weather Service
  • US Forest Service, Missoula Fire Sciences Laboratory
Date: November 14, 2019

Cataloging Information

  • ADI - Atmospheric Dispersion Index
  • air quality
  • AoR - Analysis of Record
  • ARA - Air Resource Advisor
  • atmospheric moisture
  • health impacts
  • LVORI - Low Visibility Occurrence Risk Index
  • RTMA - Real Time Mesoscale Analysis
  • URMA - Un-Restricted Mesoscale Analysis
  • visibility
Partner Site(s):
Record Maintained By:
Record Last Modified: March 27, 2020
FRAMES Record Number: 60944


The National Weather Service (NWS) Real-Time Mesoscale Analysis (RTMA) has been developed to provide a national standard Analysis of Record (AoR) for large scale verification and bias-correction efforts. The RTMA and related Un-Restricted mesoscale Analysis, or URMA has been operational since 2006 with frequent upgrades. The NWS AoR now includes many surface variables, for domains across the U.S., and will be expanded in coming years to a 3-D cube of atmospheric variables at the surface and aloft. The AoR has been a very challenging project, with issues such as steep slopes and extreme variability of weather in complex terrain, ocean/land interface complexity, choosing a quality first guess field, eliminating obviously erroneous observations, and other issues. Of particular note for the fire community, has been the challenge of generating an accurate relative humidity analysis in complex terrain. Changes are planned with coming updates to better analyze atmospheric moisture. The role of Air Resource Advisors (ARAs) for wildland fire operations has been steadily increasing. As ARA dispatch activity has increased, interaction with local NWS offices has also increased, and familiarity is growing about ARAs, and air quality issues. In the SE CONUS a long history of impactful smoke issues has led to the development of specialized products, such as the Atmospheric Dispersion Index (ADI), or Low Visibility Occurrence Risk Index (LVORI), which the NWS can calculate and provide to the fire community. These efforts have largely focused on roadway safety issues due to reduced visibility, while in the western CONUS, Alaska, etc., the focus has been on health impacts of smoke to populations and communities. The NWS Missoula has led in the development of a more uniform approach to support for ARAs from NWS field offices.

Recording Length: 0:55:06
Online Link(s):
Link to this recording (53 MB; mp4)