A severe weather warning has been issued for overnight tonight, the Minister of National Security said this afternoon.Wayne Caines said that the Bermuda Weather Service made the advisory.He explained: “The BWS indicated that over the course of this evening the island can expect to experience thunderstorms and inclement weather conditions between midnight and 6am Saturday morning. “It’s expected that wind gusts associated with the unsettled weather may exceed 50 knots.“Should the severe weather linger beyond the shelter in place end time of 6am tomorrow morning, I strongly encourage residents to exercise care and caution if they plan to move about the island.”A message circulated on social media today said: “Please be advised that Bermuda Weather Service is monitoring the development of thunderstorms approaching the area from the west overnight tonight. “These thunderstorms may develop severe characteristics.”It added: “The most likely conditions under this weather pattern are severe squalls and/or gusts exceeding 50 knots, associated with thunderstorms. “The message said that tornadoes were “less likely under this scenario, but the potential for their development will nonetheless be monitored”.James Dodgson, the BWS director, explained that the storms were the result of “an active cold front approaching from the west”.He said: “Thunderstorms are caused by warm, moist air rising. As this air rises, the water vapour within it begins to cool and condense into cloud — water droplets as well as ice crystals as temperatures fall low enough.“The rising air is known as the updraft.“As this process continues, the water droplets and ice crystals get larger and heavier, and eventually begin to drop to the ground, when the rising air can no longer hold them. “As the water droplets and ice crystals fall to the ground usually as moderate to heavy rain, but sometimes as hail, cool dry air flows downwards in the cloud. This descending air is know as the downdraft.“The combination of the moving air, water droplets and ice crystals associated with the updraft and downdraft helps electrical charge to build up within the cloud. “When enough charge has built up lightning develops.”Mr Dodgson added: “Strong gusts of wind can occur at the surface due to the downdrafts, and sometimes, with just the right conditions, tornadoes can occur — the latter generally a rare occurrence in Bermuda.”The weather service’s advisories page showed that a small craft warning was in place today until tomorrow afternoon.Winds were expected to ease to moderate and veer westerly early tomorrow morning before becoming northwesterly late at night.The forecast for Sunday included “sunny breaks” and possibly “a few passing showers” early on, with a maximum temperature of about 22C (71F).To follow the latest developments associated with this storm system visit www.weather.bm.