The National Weather Service issued a coastal flood warning at 12:26 p.m. Thursday, effective Friday between 10 a.m. and 5 p.m. for the Bronx and Queens, as well as Nassau County.

“Up to a foot of flooding above ground level is possible in vulnerable areas near shore and coast,” the weather service adds. “More coastal flooding is expected at least through the weekend.”

The weather service explains: “If you must travel, allow extra time as some roads may be closed. Do not drive around roadblocks or through waters of unknown depth. Take necessary steps to protect property at risk of flooding.”

Understanding the differences between advisories, observations and warnings

• Flash flood warning: take action!

A flash flood warning is issued when a flash flood is imminent or is already occurring. If you are in a flood-prone area, get to higher ground immediately. A flash flood is a sudden, severe flood that can develop from minutes to hours. It is even possible to experience flash flooding in areas where there is no immediate rain.

• Flood warning: take action!

A flood warning is issued when flooding is imminent or already underway.

• Flood warning: Please note:

A Flood Warning is issued when flooding is not expected to reach a level of severity that would warrant a warning. However, such a warning may cause significant inconvenience and, if ignored, may result in situations threatening life and/or property.

• Flood warning: Be prepared:

A flood warning is issued when conditions are favourable for flooding. This does not mean that flooding will occur, but it is possible.

Stay safe during floods: Expert tips from the weather service

In flood-prone regions or when camping in low-lying areas, understanding and following the weather service’s flood safety guidelines can be life-saving:

Find higher ground:

If you live in a flood-prone area or are camping in low-lying areas, the first step to safety is to move to higher ground.

Follow evacuation instructions:

If local authorities issue an evacuation order, obey it immediately. Secure your home by locking it before leaving.

Disconnect utilities and equipment:

If time permits, unplug your utilities and appliances. This will reduce the risk of electrical hazards during flooding.

Avoid flooded basements and flooded areas:

Avoid basements or rooms where sockets or cables are under water. This way you can avoid electrical accidents.

For safety reasons, evacuate immediately:

If you notice sparks or hear buzzing, crackling, popping or banging noises, leave the area immediately. Avoid water that may be live.

Stay away from floods:

Never attempt to walk through flood water. Even 15 cm of fast-flowing water can sweep you off your feet with full force.

Seek higher ground if you are trapped:

If you become trapped in running water, go to the highest possible point and call 911.

During heavy rain, the risk of flooding increases, especially in low-lying and flood-prone areas. It is important to avoid driving through water on the road, even if it appears shallow. According to the weather service, most cars can be swept away by just 30 cm of water. Stay safe by being prepared and informed.

Advance Local Weather Alerts is a service from United Robots that uses machine learning to compile the latest data from the National Weather Service.