NWS develops experimental prescribed burn planner
One day late in 2002 Pat Murphy and Andy Bailey, fire weather forecasters at the National Weather Service office in Rapid City, S.D., were discussing fire weather forecasts. Murphy was bouncing ideas off Bailey about how they could enhance services to wildland fire managers, and especially how to provide more information for managers who are trying to find weather windows for prescribed fires.
For several months the NWS had been using a new system for preparing weather forecasts. The old system meant the forecaster looked through the weather observations and the information that the various computer models predicted. They then analyzed all of this data in their heads and typed it manually into the many different forecasts that they produce every day. The same information about winds, for example, might be manually typed numerous times each day.
This new system was very different. It involved the forecaster using a computer to “paint” forecasted weather data on a map. With the help of model-driven forecasts, they would create or modify an “isobar” type line for temperature at a certain time of day, with the temperature being the same, say 60°, all along the line. Then there might be a nearby almost parallel line for the 64° readings.
Here's the revolutionary part, or one of them anyway. The computer then interpolates or extrapolates a temperature forecast for the geographical locations between the two lines. The computer makes calculations for locations on a 5km grid pattern.
This new system, called the Interactive Forecast Preparation System, produces a detailed weather forecast for all of the usual weather parameters for geographic locations every five kilometers on this grid. Theoretically, you are never more than two or three kilometers from a detailed weather forecast.
The other revolutionary development, courtesy of the IFPS, is that this detailed, location-specific forecast data can then be automatically pulled into the various text-based weather forecasts that the NWS personnel have to produce every day. They no longer have to hold the information in their heads and then manually type the same information over and over.
Murphy, after talking with Bailey, gave some thought to this wealth of very detailed digital forecast data that was at their fingertips, and he envisioned a fire manager — driven graphical display of the primary weather parameters that are in ed fire prescriptions. To develop the software he enlisted the help of Mark Mitchell of the Kansas City NWS office and Katy Fitzpatrick of the South Dakota School of Mines and Technology.
Currently, the Rapid City NWS office is testing the prescribed burn planner, along with some NWS offices in Wyoming, Colorado, Minnesota, Iowa and Kansas. Not all of these offices have it on their Web page yet, but if you call them, they may give you the Web address. The Rapid City office has a link to it at www.crh.noaa.gov/ifps/firewx.php?site=unr, if you want to experiment with it. The system will only work for the area shown on the map near the local NWS office. Unfortunately, you can't use the Rapid City page to get a forecast for California.
This new system allows a prescribed burn planner to input exact location for the project, as well as prescription parameters such as temperature, relative humidity, wind speed, wind direction, sky cover, and probability of precipitation. The output is a graphical display (see above) for the next seven days that shows a horizontal bar when you are in prescription for each parameter. The forecast data will be for the 5km grid point nearest the project.
But this only indicates if you are in prescription for each parameter or not. However, you can click on the “Link to 48-hour Element Meteogram” and see hourly forecasts for each of your prescription elements for the next 48 hours. (See page 30.)
Why would you want this hourly data? The standard spot weather forecast might say, for example, that the minimum relative humidity will be 30%. But when will this occur? It typically occurs between 1300 and 1700 hours, but if it bottoms out at 1000 hours and then rises to 70% at 1400 hours, it puts your prescribed fire out of business, possibly half-done, leaving you with a real mess to clean up. A quick glance at the Meteogram gives you an hourly display of the predicted relative humidity.
Of course, this display can't depict the detailed, terrain-influenced effects on winds, temperature or relative humidity, or inform you of other forecast dangers such as a Red Flag warning. No technology at this time can replace the forecaster looking at the specific terrain of your burn and making subtle adjustments to the forecast at that particular point. Many land management agencies require a spot weather forecast prior to igniting the prescribed fire.
Dan Morford, the assistant fire management officer and prescribed fire specialist for the national parks in the Northern Great Plains Area, has found the system to be “quite useful” and he “hopes that they continue to make it available into the fall.” He said that it's a good planning tool and is especially useful if you have to order resources in advance. However, he will continue to request spot forecasts, and will not rely entirely on the prescribed burn planner as his only source for weather forecasts.
The fire weather forecasters for the NWS will most likely use the IFPS as a basis for their spot weather forecasts, but they also will use their local knowledge and look at topographical maps and prescribed fire plans if they have them to confirm and fine-tune the spot forecast.
What's the next step? In a few months, Murphy and others will evaluate and probably revise the system, based on the input of users. It remains to be seen if the prescribed burn planner will be used in other areas.
Another concept they are toying with is using the algorithms and equations from the National Fire Danger Rating System, combined with the IFPS, to produce forecasted NFDRS indices for the next two to seven days. It could be extremely useful to see a display of the predicted burning index for the next week. Fire managers could plan their fire suppression staffing days instead of hours in advance as they do now.
Of course, all of this is based on the accuracy of the weather forecasts. We all have seen weather forecasts that were right on, and we also have seen weather forecasts that were completely wrong. However, having the hourly forecasts for four to six weather parameters will provide a safer working environment for prescribed burners as well as firefighters involved in fire suppression.
Bill Gabbert is the owner and president of Sagacity Wildfire Services and is a member of the Board of Directors of the International Association of Wildland Fire. He retired from the National Park Service in February as the fire management officer for the Northern Great Plains National Parks. Previously he worked in fire management for 20 years for the U.S. Forest Service in Southern California and also served as fire management officer for a national park in Indiana. He can be reached at gabbert@iawfonline.org.
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