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use of high-resolution wrf simulations to forecast lightning threatRecent observational studies have confirmed the existence of a robust statistical relationship between lightning flash rates and the amount of large precipitating ice hydrometeors aloft in storms. This relationship is exploited, in conjunction with the capabilities of cloud-resolving forecast models such as WRF, to forecast explicitly the threat of lightning from convective storms using selected output fields from the model forecasts. The simulated vertical flux of graupel at -15C and the shape of the simulated reflectivity profile are tested in this study as proxies for charge separation processes and their associated lightning risk. Our lightning forecast method differs from others in that it is entirely based on high-resolution simulation output, without reliance on any climatological data. short [6-8 h) simulations are conducted for a number of case studies for which three-dmmensional lightning validation data from the North Alabama Lightning Mapping Array are available. Experiments indicate that initialization of the WRF model on a 2 km grid using Eta boundary conditions, Doppler radar radial velocity fields, and METAR and ACARS data y&eld satisfactory simulations. __nalyses of the lightning threat fields suggests that both the graupel flux and reflectivity profile approaches, when properly calibrated, can yield reasonable lightning threat forecasts, although an ensemble approach is probably desirable in order to reduce the tendency for misplacement of modeled storms to hurt the accuracy of the forecasts. Our lightning threat forecasts are also compared to other more traditional means of forecasting thunderstorms, such as those based on inspection of the convective available potential energy field.
Document ID
20080013626
Document Type
Conference Paper
Authors
McCaul, E. W., Jr.
(Universities Space Research Association Huntsville, AL, United States)
LaCasse, K.
(Alabama Univ. Huntsville, AL, United States)
Goodman, S. J.
(National Oceanic and Atmospheric Administration Silver Spring, MD, United States)
Cecil, D. J.
(Alabama Univ. Huntsville, AL, United States)
Date Acquired
August 24, 2013
Publication Date
January 20, 2008
Subject Category
Meteorology and Climatology
Meeting Information
88th American Meteorological Society Annual Meeting, 3rd Conference on Meteorological Applications of Lightning Data(New Orleans, LA)
Distribution Limits
Public
Copyright
Other