Sudestada: what it is and how it affects you

What happens

When a strong southeasterly wind blows for many hours, Atlantic water piles up in the Río de la Plata estuary and the level rises above normal. If it coincides with a high tide, the rise is greater. It usually comes with rain, overcast skies, waves and low temperatures.

Which areas it affects

• Shores and islands of the Río de la Plata and the Paraná Delta, with a risk of flooding in low-lying areas and streets near the river.
• Ports, beach towns and riverside areas, where it can hinder navigation and water activities.
• Neighborhoods whose drains empty into the river: the river water can slow the runoff of rain.

How long it lasts and when it is most common

It can last from several hours to a few days, depending on how long the wind holds. It can happen at any time of year, although it is more common in autumn and winter.

What precautions to take

• If you live near the river or in a low area, stay informed and avoid leaving cars and valuables in places that can flood.
• Do not cross flooded streets or approach the shore when there are waves: the water can be deeper and faster than it looks.
• Avoid sailing and fishing from the shore while the storm lasts.
• Follow the instructions of civil protection and local authorities. In an emergency call 911.

How to follow it on this site

Check the wind and gusts for Buenos Aires on its weather page, and the estimated waves and tides on the sea page. Remember that the site's tides are estimates and do not include the effect of wind: official tides are published by the Servicio de Hidrografía Naval (hidro.gob.ar).