Wildfire Plume Structures Linked to Long-Range Spotting and Pyrometeor Transport

We link radar observations of wildfire plume structure to citizen science photographs of pyrometeors and compiled reports of spot fires for three cases. These cases include (a) the Camp Fire in 2018 using National Institute of Standards and Technology (NIST) spot fire reports, (b) the Dixie Fire in 2021, and (c) the Tamarack Fire in 2021. The radar data indicate plume structures characterized by an updraft core and a downwind fall out region. The fall out region is clearly linked to long-range spot fire occurrence during the Camp and Dixie Fires, with spotting ranges of 7 to 18 km from the fire front. During the Tamarack Fire citizen photographs show large pyrometeors (>1 cm) are frequently observed in the fall out region far downwind from the fire, though in that case no spot fires occurred. These data help establish the characteristic plume structures linked to long range spotting and provide insights into liking radar reflectivity to pyrometeor sizes.