<html><head></head><body><div style="color:#000; background-color:#fff; font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1504273591925_64958">Wow it was neat to see those effects by Daniel Wurtzel. That proves it is certainly doable on stage.<br></div><div id="yui_3_16_0_1_1504273591925_64937"><span><br></span></div><div id="yui_3_16_0_1_1504273591925_65015"><span id="yui_3_16_0_1_1504273591925_65014">I think dry ice has traditionally been used for tornado simulations, is because it goes away fast, and lingers on the ground until it is sucked up by the low pressure area. Though, quick dissipating theatrical fog juice may also do the trick. <br></span></div><div id="yui_3_16_0_1_1504273591925_65387"><span id="yui_3_16_0_1_1504273591925_65014"><br></span></div><div id="yui_3_16_0_1_1504273591925_65388"><span id="yui_3_16_0_1_1504273591925_65014"> For use on stage, perhaps you can hide fans behind some props. Though Mr. Wurtzel's work used a good many fans.</span></div><div id="yui_3_16_0_1_1504273591925_65065"><span id="yui_3_16_0_1_1504273591925_65014"><br></span></div><div id="yui_3_16_0_1_1504273591925_65200"><span id="yui_3_16_0_1_1504273591925_65014">Note that,while the fans in the videos seem to be aimed straight to center, they probably are all slightly to one side of center, so that a circular pattern develops. For scientific study of tornadoes</span><span id="yui_3_16_0_1_1504273591925_65014">, I have always seen a fan sucking air out at the top center. I wonder if a simple ceiling fan on reverse, and hung top center of stage would do the trick.<br></span></div><div id="yui_3_16_0_1_1504273591925_65201"><span id="yui_3_16_0_1_1504273591925_65014"><br></span></div><div id="yui_3_16_0_1_1504273591925_65262" dir="ltr"><span id="yui_3_16_0_1_1504273591925_65014">I wonder if a compressed air line could be fed into multiple hoses, that are hidden under some plywood, and come up through the plywood from below. Aim them similarly to Wurtzel's fans, and you have something low-profile. I guess they could even be placed on top, with one placed center but putting air down underneath the plywood to float it. Then, that floating source could glide across the stage. If the ceiling fan can also travel, then with your fog source on the wood sled, your vortex could cross stage. Dry ice is nice and portable for this, though the water would add a lot of weight, so you may need to add a slight circular ledge on the underside in the area around the dry ice tank.</span></div><div dir="ltr" id="yui_3_16_0_1_1504273591925_65548"><span id="yui_3_16_0_1_1504273591925_65014"><br></span></div><div dir="ltr" id="yui_3_16_0_1_1504273591925_65549"><span id="yui_3_16_0_1_1504273591925_65014">-Joe<br></span></div></div></body></html>