Louis J. Wicker

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Two time-splitting methods for integrating the elastic equations are presented. The methods are based on a third-order Runge–Kutta time scheme and the Crowley advection schemes. The schemes are combined with a forward–backward scheme for integrating high-frequency acoustic and gravity modes to create stable split-explicit schemes for integrating the(More)
  • Stensrud, Norman, Oklahoma Schaefer, Schneider—noaa Nws, Storm, Prediction Center +13 others
  • 2009
Warnings about convective-scale hazards are currently based on observations, but the time has come to develop warning methods in which numerical model forecasts play a much larger role. T he National Oceanic and Atmospheric Admin-istration's (NOAA's) National Weather Service (NWS) issues warnings when there is a threat to life and property from weather(More)
Manuscript (non-LaTeX) Click here to download Manuscript (non-LaTeX): zdr_paper_rev1_final.docx Abstract 1 The low levels of supercell forward flanks commonly exhibit distinct differential 2 reflectivity (Z DR) signatures, including the low-Z DR hail signature, and the high-Z DR " arc ". The 3 Z DR arc has been previously associated with size sorting of(More)
Mobile Doppler radar data, along with observations from a nearby Weather Surveillance Radar-1988 Doppler (WSR-88D), are assimilated with an ensemble Kalman filter (EnKF) technique into a non-hydrostatic, compressible numerical weather prediction model to analyze the evolution of the 4 May 2007 Greensburg, Kansas, tornadic supercell. The storm is simulated(More)
a r t i c l e i n f o a b s t r a c t The current status and challenges associated with two aspects of Warn-on-Forecast—a National Oceanic and Atmospheric Administration research project exploring the use of a convective-scale ensemble analysis and forecast system to support hazardous weather warning operations—are outlined. These two project aspects are(More)
—Tornadoes are one of nature's most destructive forces, creating winds that can exceed 300 miles per hour. The sheer destructive power of the strongest class of tornado (EF5) makes these tornadoes the subject of active research. However, very little is currently known about why some supercells produce long-track (a long damage path) EF5 tornadoes, while(More)