One of the most important parts of planning and implementing a prescribed burn is weather prediction. Weather prediction resources are available to help us make informed decisions about both fire and smoke behavior before we conduct prescribed burns. These resources can also be used by wildland firefighters to predict fire behavior so they can better focus their efforts. The resources referenced in this article are OK-FIRE and the National Weather Service (NWS).
OK-FIRE uses the Oklahoma Mesonet system, which has at least one weather station in every Oklahoma county and updates weather observations every five minutes. Weather parameters observed include air temperature, relative humidity, wind speed, wind direction, precipitation and soil temperature. The OK-FIRE website can be customized to default to the user's nearest Mesonet site. Current or recent weather conditions can be found on OK-FIRE as well as weather prediction, which is based on the North American Model (NAM). The NAM predicts weather conditions 84 hours into the future and updates four times per day. Recent, current and predicted weather conditions can be viewed in charts, graphs or maps, depending on the preference of the user.
OK-FIRE has more than just weather information. Fire and smoke behavior can be predicted using the Oklahoma Fire Danger Model and the Oklahoma Dispersion Model. The Oklahoma Fire Danger Model gives localized information on burning index, spread component, dead fuel moisture, Keetch-Byram Drought Index and others. The Oklahoma Dispersion Model helps users predict smoke behavior by providing information on dispersion condition, wind speed and wind direction. OK-FIRE also has a "Fire Prescription Planner" where users can input weather, smoke or fire parameters needed for a specific prescribed burn and check them against the most updated forecast to verify that the burn is predicted to be within prescription. If any criteria are not met, the Fire Prescription Planner tells the user when the burn is predicted to be outside prescription.
For prescribed burners inside and outside of Oklahoma, NWS has a fire weather website for weather and smoke prediction. Entering the zip code or selecting the location of the prescribed burn on the map will give localized fire weather parameters. NWS gives weather forecasts in paragraph form, charts and tables. Weather parameters given include air temperature, relative humidity, wind speed, gusts, wind direction and others. For smoke prediction, NWS gives mixing heights, transport wind speed and dispersion. NWS also has a "Weather Activity Planner" that is similar to OK-FIRE's "Fire Prescription Planner" where a user can input specific weather parameters to learn whether conditions are favorable for a prescribed burn.
It is best to use all resources available to make the most informed decision before starting a prescribed burn. We typically use both OK-FIRE and NWS to determine whether a prescribed burn is forecast to be within prescription. The use of these or similar weather prediction websites is absolutely critical for planning a prescribed burn and its safe implementation. It is good practice and strongly advised to print the weather forecast before implementing a burn so there is a record of the most up-to-date forecast. Likewise, after a burn is completed, it is a good idea to print the actual weather conditions that occurred during the burn.
The best way to learn how to use these two resources is to go online and familiarize yourself with them. Workshops will be held during fall 2012 for wildland fire managers to learn how to use OK-FIRE. Visit their website for workshop locations and details. These resources are very powerful tools to help properly plan and safely conducted prescribed burns.