Weather tracker: US cities close schools and cancel flights amid heavy snowfall | US weather

Winter Storm Hernando swept across the north-eastern US on Sunday and into the start of the week, unleashing blizzard conditions across much of the region as heavy snowfall combined with gale-force winds. Blizzard warnings were issued for several cities including New York City, Portland and Boston. More than 10,000 flights were cancelled, and schools closed in many states.

The storm intensified rapidly through Sunday. Coastal areas of Massachusetts and Rhode Island recorded gusts of about 70mph, and Montauk Point in New York reporting stronger gusts of 84mph.

By Monday, snowfall totals had surpassed 38cm (15in) in several locations, including Central Park and John F Kennedy international airport. Some communities experienced more than six consecutive hours of steady snowfall, with accumulations exceeding 76cm in parts of Massachusetts and on Long Island, New York. Rhode Island recorded 96cm by Monday night, while Fall River, Massachusetts, reached 1o4cm, making it one of the most significant snowstorms since 2016.

At the height of the storm, more than 650,000 homes and businesses were without power. Although the worst conditions eased by midweek, lighter snow, sleet, and freezing rain persisted into Thursday and Friday. At least two deaths were attributed to the severe weather.

The storm has been described as a “bomb cyclone”, a term derived from “bombogenesis”, which occurs when a mid-latitude storm rapidly intensifies, with central pressure dropping by at least 24 millibars within 24 hours. Hernando’s pressure reportedly fell by about 40 millibars in less than 12 hours – a sign of explosive development.

The rapid deepening was fuelled by a sharp contrast between relatively mild, moisture-laden Atlantic air and much colder continental air from Canada. The strong temperature gradient strengthened the storm’s circulation, while abundant moisture led to intense snowfall. Slightly warmer air in parts of the system produced heavier, wetter snow, contributing to substantial accumulations.

Meanwhile, an unusually slow-moving weather system has brought days of torrential rain to central Australia, drenching vast stretches of the Northern Territory, South Australia, Queensland and New South Wales. Persistent rain and thunderstorms linked to the stubborn low-pressure system have lashed these areas since early this week.

At Nappa Merrie in south-west Queensland, more than 165mm of rain fell in just 24 hours on Wednesday – an extraordinary deluge in a region that typically receives 100-200mm over an entire year.

The system is expected to linger over the country’s interior until at least Saturday, heightening the risk of further heavy rainfall and renewed flooding in already saturated areas.