Merrimack River entrance tidal current predictions

Now

Ebb 1.0 ktToward ESE (105°)

Next slack

9:55 PMEDT

Next max flood

2.6 ktThu 12:34 AM

Next max ebb

1.3 ktThu 5:12 AM

Knots along the channel: above the line the flood, running in toward WNW (285°); below it the ebb, running out toward ESE (105°). Times are Eastern Daylight Time. Today: slack 2:49 AM, ebb 1.4 kt 4:31 AM, slack 9:13 AM, flood 2.8 kt 12:01 PM, slack 3:02 PM, ebb 1.5 kt 5:08 PM, slack 9:55 PM.

None right now. The National Weather Service issues small craft advisories, gale and storm warnings, special marine warnings, dense fog advisories and coastal flood products for water like this.

The flood is the tidal current running in from the sea, the ebb the current running back out. Slack water is the short turn between them, when the current is weakest: the time to cross a strong channel, anchor, or dive. Slack in a channel is not the time of high or low tide; it can come hours after.

Speeds are knots along the channel's main axis, and directions are degrees true toward which the water flows, as NOAA prints its tables. A current against the wind stands the waves up steep and close together.

Predictions are astronomical: the moon and the sun, not the weather. Strong wind, river flow after heavy rain and storm surge all change the real current. This is a subordinate station: NOAA predicts it from a nearby harmonic station by fixed corrections to the times and speeds of its slack waters and maxima, so the curve between them is less exact.

• Newburyport, Merrimack RiverSubordinate current station3.0 mi
• Plum Island Sound entranceSubordinate current station7.9 mi
• Annisquam Harbor LightSubordinate current station12 mi
• Blynman Canal ent., Gloucester HarborSubordinate current station16 mi
• Odiornes Point, NNE ofSubordinate current station16 mi
• Odiornes Point, northeast ofSubordinate current station17 mi
• Little Harbor entranceHarmonic current station17 mi
• Whaleback Reef, west ofSubordinate current station17 mi

• Tide times at Plum Island, Merrimack River Entrance 0.5 mi
• Tide times at Newburyport 3.2 mi
• Tide times at Salisbury Point 5.2 mi
• Forecast for Salisbury, MA
• Open the live map with tidal currents
• All tidal current stations in Massachusetts

Tidal current predictions from NOAA’s Center for Operational Oceanographic Products and Services (CO-OPS), station ACT0816, bin 1: original at NOAA. Marine alerts from the National Weather Service.