#Interactive tornado simulator series#

#Interactive tornado simulator series#

Time series of maximum storm-relative surface wind speed (black line) and minimum surface pressure perturbation (blue line) associated with the tornado, sampled every 2 s, for the first 1,800 s of its duration (during genesis and early portion of mature stage). Black arrows indicate the location of the cyclonic vortex that becomes the long-track tornado. View is looking northwest, and the vorticity field is clipped at 2 km AGL. Values of vorticity magnitude less than 0.025 s в€’1 are not shown. Volume-rendered vorticity magnitude colored by the vertical component of vorticity ( О¶, s в€’1). The yellow arrow indicates the storm-relative path of the air within the streamwise vorticity current as it is drawn into the updraft. The red arrow points to the vortex that becomes the tornado. SVC marks the feature we call the streamwise vorticity current, and VVS marks the location of the vertical vorticity sheet. Volume-rendered vorticity magnitude with a lower threshold of 0.025 s в€’1 at t = 4,816 s, prior to tornado formation. (d) At t = 5,100 s, zoomed in on region surrounding tornado : positive w component of the wind 495 m AGL (color-filled contour, every 2 m s в€’1), surface cold pool boundary indicated by the в€’1-K contour (dashed light blue line), surface negative pressure perturbation swath (time history of minimum surface pressure, relative to the ground) contoured every 10 hPa (solid blue line), surface vertical component of vorticity ( О¶ red contours plotted every 0.1 s в€’1 starting at в€’0.15 s в€’1, with dashed negative values), surface horizontal wind and horizontal vorticity vectors plotted every 5 grid points. (a) At t = 3,600 s, surface cold pool negative (color-filled contour plotted every 1 K), positive w component of the wind at 495 m AGL (solid contour plotted every 5 m s в€’1), surface storm-relative horizontal wind vectors plotted every 22 grid points (black vectors), surface horizontal vorticity vectors plotted every 22 grid points (yellow vectors). The location of the updraft at 5 km coincides with the weak echo region (WER) in the reflectivity field at 500 m.ДҐ00-m AGL 40-dB Z reflectivity contour (thick black line), surface (color-filled values in intervals of 0.5 K), and storm-relative surface wind vectors drawn every 40th grid point (every 1.2 km) at t = 3,600 s.

(b) As in (a), at t = 3,600 s, at which point the left mover has exited the subdomain covered by the image. The storm has split into a left mover with approximate updraft centroid located at (0 km, 25 km) and a right mover, the storm that is the subject of this paper, located near (0 km, 0 km). The image covers a 70 km Г— 70 km region centered upon the updraft of the right-moving storm. (a) Updraft вЂњswathвЂќ (history of maximum w) at 5 km AGL, evaluated every model time step, translated with the moving domain (color-filled contour), and the 500 m AGL 40-dB Z reflectivity contour at t = 2,400 s. Cloud motions within this persistent inflow band from videography were consistent with an SVC. A large and long-lived tornado may be seen to the rear of where an inflow cloud band along a forward-flank boundary is moving into the storm updraft. Image courtesy of David Bock.ДЄ tornadic supercell over Carter County, Montana, on, looking toward the west. Photorealistic rendering of the supercell cloud field (looking north) at t = 7,200 s from a height of 3.7 km AGL. Wind barbs and hodograph values are shown in nautical miles per hour (full barb 10 kt 1 kt = 0.51 m s в€’1). Significant levels were calculated based on surface-based parcel ascent (as shown), with CAPE calculated using virtual temperature. The sounding and hodograph, taken from a 1-h RUC forecast off the right flank of the supercell that produced the long-track EF5 tornado near El Reno, Oklahoma.