The 8 May 2003 Oklahoma City tornadic supercell is predicted with the ARPS model using four nested grids with 9-km, 1-km, 100-m, and 50-m grid spacings. The Oklahoma City WSR-88D radar radial velocity and reflectivity data are assimilated through the ARPS 3DVAR and cloud analysis on the 1-km grid to generate an initial condition that includes a well-analyzed supercell and associated low-level m...

Cell mergers have long been believed to play a role in tornado production, although the exact mechanisms are poorly understood. Several studies have noted the resultant thunderstorm intensification that occurs during a cell merger event (e.g., Cunning et al. 1982, Westcott and Kennedy 1989). Numerical simulations (e.g., Tao and Simpson 1989, Kogan and Shapiro 1996, Bluestein and Weisman 2000) h...

Social Media and micro-blogging is being used during crisis events to provide live up-to-date information as events evolve (before, during and after). Messages are posted by citizens or public officials. To understand the effectiveness of these messages, we examined the content of geo-located Twitter messages (“tweets”) sent during the Moore, Oklahoma tornado of May 20, 2013 (+/-1day) to explor...

Without infrastructural support from base stations, mobile nodes in an ad hoc network communicate with each other in a peer-to-peer fashion. This poses a challenge in data dissemination among the mobile peers, each having limited transmission range and unpredictable mobility. In this paper, we first propose a novel mobility model to characterize user mobility in a civilian environment, such as ...

The characteristics of near-storm environments have been elucidated by several studies of observed soundings near reported tornadoes (Maddox 1976; Kerr and Darkow 1996), all soundings for multiple severe weather hazards during a complete year (Rasmussen and Blanchard 1998), or long-period samples of soundings associated with severe thunderstorms (Craven and Brooks 2004). Meanwhile, much attenti...

Tornado is a novel 256-bit block cipher that accepts a variablelength key up to 256 bits. The proposed cipher was built on an idea which gives it a dynamic nature. This nature means that the cipher execution flow varies according to the user’s input key. The confusion and diffusion processes are performed based on 10 round functions named “Storm-functions”. A selection and reordering operations...

Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from 'outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954-2014. Moreover, the variance of this quantity is increasing more than four times ...