As part of the MesoWest program, weather reports are being collected and transmitted to NWS Forecast Offices from temporary RAWS stations deployed in support of fire management operations. Surface observations are also collected from permanently deployed RAWS stations and automated stations maintained by other government agencies, educational institutions, and commercial firms in the western United States. In addition to access in the NWS AWIPS system, these observations are also available over the Internet at www.met.utah.edu/mesowest, typically within 30 minutes past the observation time. Data assimilation is used to synthesize the irregularly spaced observation onto a 10km grid over the western United Stated every 15 minutes. Surface analyses are generated by combining the MesoWest observations with a background field provided by NCEP RUC2 analyses. The data assimilation relies upon the University of Oklahoma Advanced Regional Prediction System Data Analysis System (ADAS). Applications of the MesoWest observations and ADAS analyses to fire weather operations are presented.