Cloud suck The telltale signs for a pilot climbing in the thermal under a "sucking" cloud are (1) lift strengthening, (2) lift getting smoother, and (3) widening of the thermal. Paraglider pilots have reported being unable to descend in strong cloud suck, even after bringing their canopies into deep spiral, which would normally result in a rapid vertical descent. Cloud suck is especially dangerous for paraglider pilots, whose maximum speed is less than 30 knots, because storm clouds (Cumulonimbus) can expand and develop rapidly over a large area with accompanying large areas of strong lift. On 14 February 2007 while practising for
Thunderstorm produce severe weather. A mesoscale convective system (MCS) is a complex of thunderstorms that becomes organized on a scale larger than the individual thunderstorms but smaller than extratropical cyclones, and normally persists for several hours or more. A mesoscale convective system's overall cloud and precipitation pattern may be round or linear in shape, and include weather systems such as tropical cyclones, squall lines, lake-effect snow events, polar lows, and Mesoscale Convective Complexes (MCCs), and they generally form near weather fronts. Most mesoscale convective systems develop overnight and continue their lifespan through the next day. The type that forms during the