Print Friendly and PDF

Advanced Search Results Detail

Project ID: 17-1-05-1

Year: 2017

Date Started: 08/01/2017

Ending Date:  07/31/2019

Title: Assessment of HRRR Model Forecasts of Convective Outflows in the Fire Environment

Project Proposal Abstract: The proposed work will evaluate the ability of operational and experimental versions of the High Resolution Rapid Refresh (HRRR) modeling system for the continental United State and Alaska to forecast the characteristics of mesoscale atmospheric boundaries arising from thunderstorm outflows, gust fronts, and downburst winds (referred collectively as convective outflows). The objective is to lead to enhanced situational awareness within the operational fire weather community of the ability of the HRRR model and predictive tools that rely on its output to nowcast and forecast convective outflows. Expected benefits from this project include: 1) improved understanding of the ability of HRRR data assimilation/forecast systems to forecast convectively-driven changes in wind, temperature, and moisture that influence fire behavior, which will assist fire weather forecasters in their ability to incorporate high-resolution model output in probabilistic convective outflow forecasts on time scales < 24 h. 2) improved understanding of the impacts of operational model uncertainties in convective outflow characteristics on fire spread scenarios. This will be conducted using: (1) a fire behavior tool that will rely on HRRR output combined with landscape characteristics and fuelbed flammability and (2) simulations of selected case studies using a coupled fire-atmosphere model, WRF-SFIRE. 3) improved communication methodologies for fire weather forecasters, incident meteorologists, and fire behavior analysts to inform alerts and warnings of potential and imminent risks to fire managers and fireline personnel who will be most affected by abrupt changes in weather conditions near wildfires. The research team led by the University of Utah and University of Alaska-Fairbanks has extensive experience assessing the benefits and limitations of weather forecasts for fire management applications. We will classify and examine many cases in which convective outflow boundaries were identified by on-site fire personnel to have affected fire behavior in complex terrain. We will also objectively identify convective-outflow signatures in the vicinity of wildfires using a wide-array of meteorological resources to identify their critical characteristics, e.g., duration, intensity, speed, and seasonal and time-of-day dependencies. Using an archive at the University of Utah of HRRR forecasts in the continental United States and Alaska from 2017-2018, we will then assess the ability of HRRR forecasts to detect the presence of outflow boundaries and the fidelity of the forecast guidance available from that model system to forecast them on a range of temporal and spatial scales. We hypothesize that model guidance will be most useful for: (1) nowcasts of longer-lived (< ~6 h) outflows that develop typically within preferred synoptic-mesoscale situations and (2) forecasts that provide improved situational awareness for the potential for outflows at lead times from 6-24 h rather than accurate depiction of each outflow. Validation of the numerical analyses and forecasts will be completed using a mix of spatial statistical techniques and subjective evaluation emphasizing the overall situation from the perspective of what a forecaster or fire behavior analyst would be able to establish from ~24 hours prior to until immediately before any major changes in the atmospheric state that would affect fire behavior. The proposed study will equip incident meteorologists and fire behavior analysts assigned to major fires and NWS WFO forecasters and predictive service personnel in the continental United States and Alaska with improved situational awareness of the potential for outflows and their impacts on fire behavior when they examine HRRR output operationally. In order to do so, operational personnel will help evaluate how to interpret the results of the validation studies and design procedures and best practices to inform the wider community.

Principal Investigator: John D. Horel

Agency/Organization: University of Utah

Branch or Dept: Department of Atmospheric Sciences

Other Project Collaborators




Branch or Dept

Agreements Contact

Erica C. Trejo

University of Utah

Office of Sponsored Projects

Budget Contact

Erica C. Trejo

University of Utah

Office of Sponsored Projects

Co-Principal Investigator

Erik T. Crosman

University of Utah

Department of Atmospheric Sciences

Co-Principal Investigator

Adam K. Kochanski

University of Utah

Department of Atmospheric Sciences

Co-Principal Investigator

Robert H. Ziel

University of Alaska-Fairbanks

Office of Sponsored Programs


Trevor I. Alcott

NOAA-National Oceanic & Atmospheric Administration

Global Systems Division


Charles Maxwell

Forest Service

SWCC-Southwest Area Coordination Center


Heidi S. Strader

NPS-National Park Service

Alaska Regional Office-Fairbanks

Project Locations

Fire Science Exchange Network




Great Basin

Great Plains

Lake States

Oak Woodlands

Northern Rockies




Southern Rockies



North Atlantic







Project Deliverables

There is no final report available for this project.
There are no deliverables available for this project.

Supporting Documents

There are no supporting documents available for this project.

Convert PDF documents to an html document using Adobe's online conversion tool.
Download Adobe Acrobat Reader