Using the 21 June 2008 California Lightning Outbreak to Improve Dry Lightning Forecast Procedures

Abstract

An anomalous lightning event occurred on 20-21 June 2008 in central and northern California. Most of the thunderstorms produced frequent lightning with little precipitation, resulting in over 1500 new fires. Many of these fires became large, and massive firefighting efforts continued through August in order to contain all the fires. This event was not well forecast, with only isolated lightning strikes expected. Several computer model forecast parameters pointed toward the impending lightning outbreak, including satellite and lightning observations, as well as model data from 19 June. An existing procedure to forecast dry thunderstorms showed the strong possibility of a thunderstorm outbreak over California. This procedure proved to be helpful, but has been modified to better handle moisture advection and low-level forcing, which provides a more comprehensive framework for forecasting potential dry thunderstorm outbreaks.

The 2013 Rim Fire: Implications for Predicting Extreme Fire Spread, Pyroconvection, and Smoke Emissions

“…In combination with upper-level meteorology, several studies have employed traditional stability indices, such as convective available potential energy (CAPE), to estimate the buoyancy available for dry-thunderstorm development (e.g., Peterson et al 2010;Wallmann et al 2010) and high-altitude smoke plumes (Potter 2005). The calculation of CAPE is either based on lifting a surface parcel, the most unstable parcel in the lower troposphere (e.g., lowest 300 hPa), or a parcel with the mean properties of the lower troposphere (Bunkers et al 2002;Wallace and Hobbs 2006).…”

Impact of the North American monsoon on wildfire activity in the southwest United States

“…Strong diurnal heating and upslope flow can create a deeply mixed boundary layer and thermally induced circulations that can utilize increased mid‐tropospheric moisture and produce thunderstorms (Hales, ). With lower‐tropospheric moisture confined farther south, an environment conducive for dry thunderstorms develops with characteristic inverted‐v soundings where a dry sub‐cloud layer and high LCL forms an inverted‐v between the dewpoint and temperature profiles (Figures , and , MTs 4, 8, 11–12 and Table ) (Hall, ; Wallmann et al, ; Nauslar et al, ). Transient upper‐tropospheric shortwave troughs and easterly waves also act to increase buoyancy and augment coverage of thunderstorms by lowering heights and temperatures aloft.…”

Effects of Climatic Warming and Wildfires on Recent Vegetation Changes in the Lake Baikal Basin

“…The CG dry strikes are generated in the elevated moisture plume at 700-500 hPa and have ordinary negative polarity. Details regarding forecast predictions of dry thunderstorms can be found in References [53][54][55][56].…”