Red Flag Threat Index (RFTI) provides a simple numerical and categorical rating which quantifies the threat posed by combinations of relative humidity and wind speed with respect to local climatological significance and past large wind-driven grassland wildfires. RFTI terms are based on statistical quartile rankings for a 10-year climatological database of critical fire weather observations, or observations exceeding the local Red Flag Warning criteria, at the location of interest. During the development of the RFTI, such climatological thresholds of 2-m relative humidity and 6-m wind speed were found at Amarillo (KAMA), Lubbock (KLBB), and Midland (KMAF) spanning 2000-2009. Note, 10-m observed wind speeds were reduced to 6-m via a 0.886 factor as observed by the WTM at Reese Center during diurnal burn periods (Lindley et al. 2011). RFTI was modeled after the Haines Index (Haines 1988), in that it used meteorological variables to rate fire danger independently of fuels. The Haines Index, however, assesses risk based on temperature-dewpoint depressions and lapse rates, and is thus primarily an indicator for plume-driven wildfires. In the Great Plains which include the eastern plains of New Mexico, relative humidity and wind speed are the most commonly used predictors for wind-driven grassland fires. (Lindley et al. 2011).