ROME, Italy (AP) — The floods that sent rivers of mud tearing through towns in Italy’s north-east are another drenching dose of climate change’s all-or-nothing weather extremes, something that has been happening around the globe, scientists say.

The coastal region of Emilia-Romagna was struck twice, first by heavy rain two weeks ago on drought-parched ground that could not absorb it, causing rivers to overflow overnight, followed by this week’s deluge that killed 14 and caused damages estimated in the billions of euros.

In a changing climate more rain is coming but it’s falling on fewer days and in less useful and more dangerous downpours.

The hard-hit Emilia-Romagna region was particularly vulnerable. Its location between the Apennine mountains and the Adriatic Sea trapped the weather system this week that dumped half the average annual amount of rain in 36 hours.

“These are events that developed with persistence and are classified as rare,” Fabrizio Curcio, the head of Italy’s Civil Protection Agency, told reporters.

Authorities said that 43 towns were impacted by flooding and landslides, and that more than 500 roads had been closed or destroyed.

Antonello Pasini, a climate scientist at Italy’s National Research Council, said a trend had been establishing itself: “An increase in rainfall overall per year, for example, but a decrease in the number of rainy days and an increase in the intensity of the rain in those few days when it rains,” he said.

Italy’s north has been parched by two years of drought, thanks to less-than-average snowfall during the winter months. Melting snow from the Alps, Dolomites and Apennines normally provides the steady run-off through spring and summer that fills Italy’s lakes, irrigates the agricultural heartland, and keeps the Po and other key rivers and tributaries flowing.

Without that normal snowfall in the mountains, plains have gone dry and riverbeds, lakes and reservoirs have receded. They cannot recover even when it rains because the ground is essentially “impermeable” and the rain just washes over the topsoil and out to the sea, Pasini said.

“So, the drought is not necessarily compensated for by these extreme rains,” he said, “because in northern Italy the drought depends more on snow being stored in the Alps than on rain — and in the last two years we have had very little snow.”

Civil Protection Minister Nello Musumeci said the new normal of extreme weather events in the Mediterranean requires Italians to adapt and Italy to rethink its flood protection policies nationwide. He cited a fierce, storm-triggered landslide last fall on the southern island of Ischia, off Naples, that left 12 dead.