The National Weather Service issued a coastal flood warning at 3:07 p.m. Thursday, effective for Essex, Suffolk, Norfolk, Plymouth, Barnstable, Dukes and Nantucket counties between 10 a.m. and 3 p.m. Friday.

The weather service states: “Flooding of up to one foot above ground level is expected in low-lying areas near coastlines and tidal waterways (3.2 to 13.5 feet mean lower low tide).”

“Shallow floodplains less than a foot deep are affecting the lowest areas along the coast, including Morrissey Boulevard in Boston. The roads remain passable. Shallow flood plains less than a foot deep will impact more vulnerable coastal roads along the north shore of Salem and …” From Gloucester to Newburyport, coastal road flooding is likely at high tide. Flooding less than a foot deep may occur in low-lying areas and roads near Nantucket Harbor,” the weather service explains. “If travel is necessary, allow extra time as some roads may be closed. Do not drive around barricades or through water of unknown depth. Take necessary measures to protect flood-prone property.”

Deciphering Notices, Watches and Warnings: Understanding Weather Alerts

• Flash flood warning: take action!

A flash flood warning is issued when a flash flood is imminent or occurring. If you find yourself in a flood-prone area, move to higher ground immediately. A flash flood is a sudden, intense flood that can take minutes to hours to develop. Flash flooding may even occur in areas where it does not rain immediately.

• Flood warning: take action!

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

• Flood Warning: Be Aware:

A flood warning is issued when flooding is not expected to reach a level of severity requiring a warning. However, considerable inconvenience can occur and, if caution is not exercised, potentially life-threatening and/or property-related situations can arise.

• Flood watch: Be prepared:

A flood warning is issued when conditions are favorable for flooding. It is not a guarantee that flooding will occur, but it does mean that the possibility exists.

Be prepared for floods: expert guidance from the weather service for your safety

Flooding can pose a significant hazard, especially if you live in a flood-prone area or are camping in a low-lying region. To ensure your safety, the Weather Service offers important flood protection guidelines:

Go to a higher level:

If you are in a flood-prone area or camping in a low-lying location, your first step should be to move to higher ground.

Follow the evacuation instructions:

If local authorities issue an evacuation order, follow it immediately. Before leaving, secure your home by locking it.

Disconnect utilities and devices:

If time permits, disconnect your utilities and appliances. This reduces the risk of electrical hazards during flooding.

Avoid flooded basements and flooded areas:

Avoid basements or flooded rooms with electrical outlets or cords. Preventing electrical accidents is crucial.

Evacuate immediately for safety reasons:

If you notice sparks or hear humming, crackling, snapping or popping noises, evacuate immediately. Avoid water that may be electrically charged.

Stay away from flooding:

Never attempt to walk through flood water, even if it appears shallow. Just 15 centimeters of water with high current speed can force you off your feet.

Find high ground if trapped:

If you become trapped by running water, get to the highest point available and call emergency services at 911.

During heavy rainfall, the risk of flooding increases, especially in low-lying and flood-prone regions. Always remember to never drive through water on the road, no matter how shallow it may be. According to the weather service, just 30 cm of fast-moving water can sweep away most vehicles. Prioritize your safety by staying informed and prepared.

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