Shortwave (meteorology)
A shortwave or shortwave trough is an embedded kink in the trough / ridge pattern. Its length scale is much smaller than that of longwaves, which are responsible for synoptic scale systems, although shortwaves may be contained within or found ahead of longwaves and range from the mesoscale to the synoptic scale. Shortwaves are most frequently caused by either a cold pool or an upper level front.
Corresponding weather and effects
Shortwaves are often associated with warm (WAA) or cold air advection (CAA), which influence temperature. Due to the way they curve the air that moves around them and the way air moves away from them, shortwaves produce positive curvature vorticity and positive shear vorticity, respectively. Ahead of a shortwave there is large-scale lift due to divergence from positive vorticity advection (PVA). This lift often sparks precipitation. In a capped environment, the lift generated by a shortwave may cool the inversion layer through adiabatic cooling, allowing for deep, moist convection.
External links
- What is a shortwave trough?. Haby's Hints.
- Shortwave Trough. NWS Glossary.