Floodwaters swept two parked cars through the main pedestrian street on the Aegean island of Skiathos, as a storm with heavy rain and gale-force winds kept much of Greece on alert for a second day.
An emergency 112 alert before dawn urged Skiathos residents to limit travel to the absolutely necessary.
Mayor Thodoris Tzoumas said fire, police and municipal crews were working across the island.
Flooding also hit nearby streets, and Greek media report seven regions are under the civil protection service's red alert level.
The meteo.gr forecasting service said the heaviest, longest rain is expected in the eastern mainland, Evia, the Sporades, the northern and eastern Aegean, the Dodecanese and Crete. Large rainfall totals are possible in the Sporades, Evia and possibly northern Attica, with hail likely in the Dodecanese and Crete. Light snow may fall on higher ground in central and northern mainland Greece, and temperatures drop further.
Northeast winds reach 7 to 8 Beaufort in the northern Aegean and 6 to 8 elsewhere, with gusts of 90 to 100 kilometers per hour, easing slightly from the afternoon.
Attica will see rain and possible storms, with brief heavy bursts in the north, and highs of 15 to 19 degrees Celsius.
Thessaloniki expects passing showers and clearing from midday.
Problems began Tuesday in Attica and other areas.
The storm follows days of heavy rain and flooding in Crete last week.