A storm-scale region of rotation, around 3-10 kilometres in diameter and often found in the left rear flank of a supercell (or often on the eastern, or front, flank of an HP storm). The circulation of a mesocyclone covers an area much larger than the tornado that may develop within it.
Synoptic Scale (or Large Scale): The typical weather map scale that shows features such as high and low pressure areas and fronts over a distance spanning a continent. Also called cyclonic scale. Compare with mesoscale and storm-scale.
Mesocyclone - A storm-scale region of rotation, typically around 2-6 miles in diameter and often found in the right rear flank of a supercell (or often on the eastern, or front, flank of an HP storm).
WATERSPOUT A small, weak tornado, which is not formed by a storm-scale rotation. It is generally weaker than a supercell tornado and is not associated with a wall cloud or mesocyclone. It may be observed beneath cumulonimbus or towering cumulus clouds and is the water equivalent of a landspout.
Outflow Boundary - A storm-scale or mesoscale boundary separating thunderstorm-cooled air (outflow) from the surrounding air; similar in effect to a cold front, with passage marked by a wind shift and usually a drop in temperature.
Bear's Cage Slang for a region of storm-scale rotation, in a thunderstorm, which is wrapped in heavy precipitation. This area often coincides with a radar hook echo and/or mesocyclone, especially one associated with an High Precipitation (HP) storm.
The term mesoscale is a size scale referring to weather systems smaller than synoptic scale systems but larger than storm-scale cumulus systems. Horizontal dimensions generally range from around 50 miles to several hundred miles.
Size scale referring to weather systems smaller than synoptic-scale systems but larger than storm-scales ???ystems. Horizontal dimensions generally range from around 50 miles to several hundred miles. Squall lines, MCCs, and MCSs are examples of mesoscale weather systems.
Often it is visible only as a debris cloud or dust whirl near the ground. Gustnadoes are not associated with storm-scale rotation (i.e. mesocyclones); they are more likely to be associated visually with a shelf cloud than with a wall cloud.
The strongest visual clues in identifying this type of supercell usually are the curving inflow bands and mid-level cloud bands which wrap around the updraft, both suggestive of storm-scale rotation. This dramatic storm produced large hail but no known tornadoes.