Analyses of Fire-Effective Low-Level Thermal Ridges on the Southern Great Plains

During the past decade, seminal research concerning wildland fire episodes within the grass-dominated fuelscape of the southern Great Plains has led to improved forecasts and warnings. Much of this advancement has focused upon synoptic-scale composites of fire-effective midlatitude cyclones. However, a meso-scale commonality associated with significant wildfires on the southern Great Plains is the presence of low-level tropospheric thermal ridges. Analogous to the well documented fire-effectiveness of the West Coast Thermal Trough, low-level thermal ridges appear to have dramatic influences on fire activity across the southern Great Plains. In fact, identification of these features in proximity to midlevel wind maxima has proven useful in forecasting the evolution, intensity and areal scope of regional wildfire outbreaks. This study will provide detailed meteorological analyses of fire-effective low-level thermal ridges on the southern Great Plains. The North American Regional Reanalysis will be used to investigate atmospheric characteristics of low-level thermal ridges associated with widespread fire activity during the 9 April 2009, 27 February 2011, 9 April 2011, and 14 April 2011 firestorms on the southern Great Plains, as well as the 11 May 2014 Double Diamond fire, the most devastating fire (per home loss) in Texas Panhandle history. These analyses will show that low-level thermal ridges are often a dominant meteorological factor supporting ignition and extreme wildland fire behavior on the southern Great Plains, with a tendency for intense wildfires to occur on the windward side of pronounced low-level thermal ridges.