• How does a unit select a process for generating PAL values for a unit or project area?

Following are the basic steps that a Forest should follow to evaluate and select the fire danger rating area(s), or weather station(s) for a project area.

• Review weather station locations and fire danger rating areas on the Forest. This information should be documented in the Fire Danger Rating Operating Plan and or the Fire Management Plan. It is important to understand what weather stations are in each fire danger rating area, and how the fire danger rating areas relate to the various portions of the Forest. An understanding of how PAL values relate to traditional percentiles in each fire danger rating area and the thresholds utilized in the PocketCard is also valuable.

• Review the PAL seasonal climatology for each of the weather station on the Forest to understand the expected frequency of occurrence of the different PAL levels across the Forest. This information has been provided to the Forests several times over the past several years.  Copies are available from the North Ops Predictive Service Unit.

• Evaluate the three typical scenarios for issuing PAL values on a daily basis; (1) by fire danger rating area, (2) by a group of fire danger rating areas, and (3) by individual weather station using the seasonal PAL climatologies. Are the station climatologies similar within each of the fire danger rating areas? Are there significant differences when comparing stations over the same period of time? What might be causing this?  Discuss your concerns with the Predictive Services Units.

• Select the most preferred option from a Forest perspective for issuing daily PAL values. PAL was designed to operate on a landscape (fire danger rating area) scale and this approach or the grouped fire danger rating areas approach should blend best with the existing daily fire danger rating based decisions already made at the Forest level.

• Generate the PAL days per month for each individual weather station and for the approach the Forest selected to issue PAL values on a daily basis. The steps in the analysis process using FireFamily Plus and the PAL days per month spreadsheet are outlined in the “PAL Analysis- How to” document.

• Review the monthly PAL day trends and compare the stations to each other and to the Forest’s selected approach to issuing the daily PAL values.  Do the relationships still seem to be logical? No significant differences that cannot be explained? The Predictive Service Units at North Ops and South Ops can provide advice and counsel at this point.

• Establish the necessary Special Interest Groups (SIGs) in the Weather Information Management Systems (WIMS) to deal with PAL. See the information on the CD that was provided to each Forest at the July 2003 BOD meeting. (This will only be necessary if the Forest is using a different group of stations for PAL values verses what it uses for daily fire danger rating based fire management decisions.)

• Utilize the functionality of WIMS to compare the Observed PAL values to the Forecast PAL values as generated by the National Fire Danger rating System (NFDRS) processor for the 2005 season using the capabilities of a spreadsheet. The review should look at May through the period of time the National Weather Service was providing forecast (early November). Is there a good relationship between what was forecast and what actually happened? If consistent anomalies are present, they need to be reviewed and discussed with the Predictive Service Units to better understand what may be going on. Are the anomalies forecast issues, station issues, management of the model in WIMS issues?

The group(s) of weather stations may contain Forest Service as well as other agency’s weather stations within the same fire danger rating area.  The key is that they meet NFDRS weather station location and operational standards.  This guidance is provided in the Weather Station Handbook an Interagency Guide for Wildland Managers (PMS-426-2) and NWCG National Fire Danger Rating System Weather Station Standards (PMS 426-3).