Mid-latitude cyclones :

Mid-latitude cyclones, also known as extratropical or temperate cyclones, are formed in regions of strong temperature contrasts, specifically along the polar front where warm tropical air masses meet cold polar air masses [3]. This temperature gradient creates baroclinic instability, leading to the dynamic origin of these systems [2]. Unlike tropical cyclones, they occur over both land and ocean and are a primary source of mid-latitude cloud formation and precipitation. Regarding the other options: they typically move from west to east under the influence of the westerlies and the polar jet stream [5]. They are characterized by significant cloud cover and precipitation rather than clear skies, often producing 80% of extreme precipitation events in mid-latitude regions. Therefore, their formation in regions of strong temperature contrast is their defining characteristic.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 28: Temperate Cyclones > 28.2. Fronts > p. 398
2. [3] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 9: Atmospheric Circulation and Weather Systems > Extra Tropical Cyclones > p. 82
3. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 28: Temperate Cyclones > 28. Temperate Cyclones > p. 395
4. [5] https://www.weather.gov/media/zhu/ZHU_Training_Page/Miscellaneous/cyclones_anticyclones/cyclones.pdf