- Rainstorms (thunderstroms) and duststorms arise from similar meteorological conditions.
- They are almost always preceded and caused by spell of intense heat.
- Thunderstorms occur when atmosphere has moisture and duststorms take place when moisture is not present.
- Such events take place due to local instability arising out of deviation from normal temperature difference between upper and lower atmosphere.
- Thus, these events themselves are very localised both in time and space.
- In recent rainstorms and duststorms cases in Uttar Pradesh and Rajasthan, moist easterly winds from Bay of Bengal reached up to Himachal Pradesh colluded with dry winds from north-westerly direction.
- The two systems destabilised equilibrium temperature difference between upper and lower layers of atmosphere, leading to conducive conditions for thunderstorm and duststroms.
- The final trigger, however, is development of largescale air-circulation system. Many parts of India witness build-up of surface heat during this time of year.
- The places that were hit by recent storms had seen heat-wave like conditions.