The heat wave had tightened its grip over Bihar as early as in end-March this year.

The mercury has been soaring to new levels every day, with several cities in the state witnessing record-breaking maximum temperatures. Moreover, the worst is yet to come as we proceed further into summer.

Temperatures in Patna have shot to around 40ºC with heat-wave conditions prevailing across the state. However, marginal relief is in store with the weather department predicting thunderstorms and squalls at few places in the state on April 6 and 7, which the Met department has said will decrease the temperature by 2ºC.

As a result, Patna's maximum temperature slid to 33.5ºC from Monday's 40ºC.

Patna Met director Sumendu Sengupta said: "Westerly winds have been blowing in the state over the past three days, pushing up the day temperature. Earlier, we use to see these weather conditions after April 20, but this year, hot winds have started blowing in the first week of April itself. This is because of absence of any significant weather system over the region."

However, the Met director said from Thursday, parts of Bihar, particularly its northeastern region, is expected to witness light rainfall as well as thunderstorm activities. In fact, the possibility of lightning also cannot be ruled out over these areas, Sengupta said.

Areas, including Purnea, Kishanganj and other regions in northeastern Bihar, are expected to witness light showers with lightning strikes.

India Meteorological Department (IMD) on Tuesday also warned against the possibility of thunderstorm accompanied by squall/hail in isolated places over eastern Bihar.

Explaining the reason behind expected thunderstorms, a Met department official said: "These weather conditions can be attributed to the presence of several weather feature systems in close proximity to this region. While a cyclonic circulation persists over north Bihar, a trough extends from this system up to Chhattisgarh across Jharkhand. Not only this, another east-west trough can be seen running from north Bihar to Nagaland across Bangladesh. The regions, which weather activities will hit, are expected to witness a slight drop in temperatures. However, other parts will continue to observe hot weather conditions during the next few days."

Sengupta too said any relief in form of any pre-monsoon activity will be short-lived and will not have any impact on the rising mercury.

The IMD, in an innovative step, has decided to share heat-wave data with the Red Cross and Medical Council of India (MCI) in an effort to help the administration fight the weather conditions in a better way. It also plans to launch a pilot project to create 29 climate outlook fora by picking at least one district from a state for heat-wave preparedness.

Climate outlook fora refer to climate prediction centres responsible for issuing seasonal climate outlook andprobabilities of temperature and precipitation departing from normal.