Abstract
In this paper, we describe and analyze a climatology of the Hot-Dry-Windy Index (HDW), with the goal of providing fire-weather forecasters with information about the daily and seasonal variability of the index. The 30-year climatology (1981–2010) was produced using the Climate Forecast System Reanalysis (CFSR) for the contiguous United States, using percentiles to show seasonal and geographical variations of HDW contained within the climatology. The method for producing this climatology is documented and the application of the climatology to historical fire events is discussed. We show that the HDW climatology provides insight into near-surface climatic conditions that can be used to identify temperature and humidity trends that correspond to climate classification systems. Furthermore, when used in conjunction with daily traces of HDW values, users can follow trends in HDW and compare those trends with historical values at a given location. More usefully, this climatology adds value to HDW forecasts; by combining the CFSR climatology and a Global Ensemble Forecast System (GEFS) ensemble history and forecast, we can produce a single product that provides seasonal, climatological, and short-term context to help determine the appropriate fire-management response to a given HDW value.
Highlights
The Hot-Dry-Windy Index (HDW), which was introduced by [1], combines the meteorological basic observed variables [2] of temperature, humidity, and wind speed into a tool that can help fire-weather forecasters predict when weather conditions will make a wildland fire difficult to manage.The results of [1] demonstrate that HDW can identify days on which synoptic- and meso-alpha-scale weather processes contribute to especially dangerous fire behavior
If used in a forecast mode, HDW can highlight upcoming days when meteorological conditions could contribute to more dangerous fire behavior, and this information could be used by fire managers to help assess the potential for an ongoing wildland fire to threaten lives and property
While the climatology alone provides a useful overview of the HDW distribution at a specific location, it is possible to combine the climatology with a daily trace of HDW values for a given time range to identify the frequency at which these values occur
Summary
The Hot-Dry-Windy Index (HDW), which was introduced by [1], combines the meteorological basic observed variables [2] of temperature, humidity, and wind speed into a tool that can help fire-weather forecasters predict when weather conditions will make a wildland fire difficult to manage. If used in a forecast mode, HDW can highlight upcoming days when meteorological conditions could contribute to more dangerous fire behavior, and this information could be used by fire managers to help assess the potential for an ongoing wildland fire to threaten lives and property. A forecaster must be able to communicate to a fire manager what represents a “high” HDW value for a given location so the fire manager knows when to take note. To address this need, we developed a 30-year climatology of HDW values that can be used to contextualize an HDW trace for a given fire event. The climatology allows a fire-weather forecaster to assess HDW values on both daily and seasonal timescales and provides a climatological context.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call