Grape Island tidal current predictions

Now

Ebb 0.2 ktToward NNW (345°)

Next slack

4:45 AMEDT

Next max flood

0.5 kt8:13 AM

Next max ebb

0.4 kt2:12 AM

Knots along the channel: above the line the flood, running in toward SSW (203°); below it the ebb, running out toward NNW (345°). Times are Eastern Daylight Time. Today: ebb 0.4 kt 2:12 AM, slack 4:45 AM, flood 0.5 kt 8:13 AM, slack 12:04 PM, ebb 0.4 kt 2:47 PM, slack 5:09 PM, flood 0.5 kt 8:27 PM.

• Storm Warning Storm Warning issued September 25 at 2:58PM EDT until September 26 at 8:00PM EDT by NWS Boston/Norton MAUntil 8:00 PM
  Full text

  * WHAT...Northeast winds 20 to 25 kt with gusts up to 50 kt and waves around 3 feet. * WHERE...In Massachusetts coastal waters, Boston Harbor. In Rhode Island coastal waters, Narragansett Bay. * WHEN...Until 8 PM EDT Saturday. * IMPACTS...Storm force winds and hazardous waves will capsize or damage vessels and reduce visibility.

  Mariners should remain in port, alter course, and/or secure the vessel for severe conditions.

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.

• Grape Island and Lower Neck, betweenSubordinate current station0.4 mi
• Jacknife LedgeHarmonic current station0.8 mi
• Sheep Island, 0.3 nmi west ofSubordinate current station0.9 mi
• Stodders Neck, Weymouth Back RiverSubordinate current station1.0 mi
• The Piglets, 0.4 nmi northest ofHarmonic current station1.1 mi
• Pig Rock, northwest ofSubordinate current station1.1 mi
• Pig Rock, north ofSubordinate current station1.1 mi
• Bumkin Island, 0.4 nmi west ofSubordinate current station1.3 mi

• Tide times at Nut Island, Quincy Bay 1.4 mi
• Tide times at Crow Point, Hingham Harbor entrance 2.0 mi
• Tide times at Weymouth Fore River Bridge 2.3 mi
• Forecast for Hull, 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 ACT1501, bin 1: original at NOAA. Marine alerts from the National Weather Service.