Recognizing the Potential for Dangerous Nocturnal Fire Growth and its Implications on Fire Weather Products and Services

Recognition of conditions which support nocturnal extreme fire behavior (EFB) can pose a challenge to forecasters, especially since numerical weather prediction (NWP) tools are limited in their ability to initialize highly dynamic, but relatively small-scale features. Large fires can drastically alter nocturnal stability which can quickly lead to nocturnal EFB and directly impact public safety. During the night of 22-23 Apr 2009 the Highway 31 Fire in Horry County, SC exhibited EFB when NWP indicated a stabilizing environment. In a matter of a few hours, the fire consumed 2000 ha, destroyed 76 homes and damaged another 96 structures. To assess the potential for nocturnal EFB, it is imperative forecasters conduct an analysis which includes: antecedent conditions, ventilation rate, visual observations, National Weather Service (NWS) Weather Surveillance Radar (WSR-88D) imagery, and stability profiles. This research provides weather forecasters with factors that contributed to the nocturnal EFB observed during the Highway 31 Horry County fire, an overview of a Nocturnal Fire Growth (NFG) sounding, how to assess potential nocturnal EFB through a decision tree, and the Impact-based Decision Support service (IDSS) implications for the 22-23 Jun 2011 Juniper Road fire in Pender County, NC.