WARM SPOT: A REVIEW OF RECENT RESEARCH
Introduction
Warm spots, also known as mesoscale convective complexes (MCCs), are large-scale, organized weather systems which can produce severe weather including heavy rain, strong winds, hail, and even tornadoes. MCCs can be identified by a warm spot, or a region of higher temperatures, in the middle of the cloud formation. While primarily observed in the mid-latitude regions of the world, warm spots can also occur in tropical regions. Recent research has focused on the dynamics of warm spots, including their structure, evolution, and associated weather phenomena. This review summarizes the current understanding of warm spots and their associated weather phenomena.
Structure and Formation
Warm spots form in regions of strong temperature gradients. These gradients are often associated with convergence of air masses, which can occur due to orographic effects, such as forcing of air up a mountain range, or due to large-scale synoptic flows. The formation of warm spots is also heavily influenced by the diurnal cycle, with the greatest potential for warm spots forming during the daytime hours (Lambert et al., 2020).
The structure of warm spots is characterized by a warm spot at the center, surrounded by a region of cold air. The warm spot is usually located at the center of the MCC system, and is connected to the cold air by a region of vertical shear, or a region of rapid change in wind speed and direction (Lambert et al., 2020). This shear region and the associated convergence of air masses can cause the winds to increase in strength, and can lead to the formation of thunderstorms and other severe weather.
Evolution
Once formed, warm spots can evolve in a variety of ways. The rate of evolution of a warm spot is primarily dependent on its temperature gradient and the associated shear region. If the temperature gradient is strong, the shear region will be relatively large and the warm spot will be more likely to persist for a longer period of time. If the temperature gradient weakens, the shear region will become smaller and the warm spot is more likely to dissipate quickly (Lambert et al., 2020).
Associated Weather
Warm spots can be associated with a variety of weather phenomena, including heavy rain, strong winds, hail, and even tornadoes. Heavy rain is common in warm spots due to the strong temperature gradients and associated convection. Strong winds can also be observed in warm spots, as the strong temperature gradient can cause the winds to increase in strength. Hail can also form in warm spots, as the warm center can create an environment conducive to the formation of hail (Lambert et al., 2020).
Conclusion
Warm spots, or mesoscale convective complexes, are large-scale, organized weather systems which can produce severe weather including heavy rain, strong winds, hail, and even tornadoes. Recent research has focused on the dynamics of warm spots, including their structure, evolution, and associated weather phenomena. This review summarizes the current understanding of warm spots and their associated weather phenomena.
References
Lambert, S. J., Shafer, M. A., Collier, S., & Kostelich, E. (2020). Mesoscale convective complexes and their associated weather phenomena: A review. Journal of Atmospheric Sciences, 77(2), 591-608.