THUNDERSTORMS are classified as:

• Air mass type (heat thunderstorms) - more common in summer time.
• Frontal type - more common in winter time, usually formed in a line at a cold front or occlusion and often accompanied by a squall line. Frontal Thunderstorms are the fastest moving.

Air mass thunderstorms occur independently of fronts or other large-scale mechanisms that cause air to rise. They are typically associated with hot and humid summer conditions, earning them the nickname "heat thunderstorms." These storms form due to the combination of heat, humidity, and atmospheric instability. A deep layer of instability, created by the Environmental Lapse Rate (ELR) and a ready supply of moist air, can lead to thunderstorm activity when an uplift trigger is present. This trigger is often thermal uplift or convection resulting from surface warming, which is most intense in the early afternoon. As the surface temperature increases, the lapse rate steepens, creating greater instability and leading to the development of widespread thunderstorms.