High Tide Bulletin: Fall 2018

When you may experience higher than normal tides between September and November 2018.

The rising and falling of the sea is a phenomenon upon which we can always depend. Tides are the regular rise and fall of the sea surface caused by the gravitational pull of the moon and sun and their position relative to the earth. There are some factors that cause the tides to be higher than what is "normally" seen from day to day. This bulletin tells you when you may experience higher than normal high tides for the period of time between September and November 2018. We also publish annual high tide flooding reports that present a broad outlook of what to expect for a given year in terms of high tide flooding, as well as a summary of high tide flooding events for the previous calendar year.

This fall, an El Nino is predicted to form. If that happens, it will bring a higher chance of flooding along the U.S. East and West Coasts this fall and winter.

Regional outlook map

Select a region below to see when you may experience higher than normal tides from June to August 2018. Depending on non-tidal conditions (wind, storms, etc.) regions may experience impacts before or after the dates mentioned here.

NOTE: Higher than normal high tides alone do not necessarily cause coastal flooding. However, higher-than-normal high tides are becoming increasingly impactful due to continued sea level rise. High tide flooding that causes a nuisance along the coast (such as flooded streets, washed out beaches)  is more likely to occur during these periods depending on your location along the coast.  More severe flooding may result if adverse weather—heavy rains, strong wind, or big waves—conditions are present.

Northeast Outlook

Includes Maine, New Hampshire, Massachusetts, Connecticut, and New York

When will the tides be higher than normal?

  • September 9 - 11
  • October 8 - 10

Why will they be higher than normal?

  • Mean sea level is generally higher in the early fall months in the northeast due to warmer, expanding ocean water and changes in weather patterns.
  • A perigean spring tide will be occurring. This is when the moon is either new or full and closest to earth. Higher than normal high tides and lower than normal low tides will occur.
  • An El Nino is forecasted to begin strengthening in the fall. Along the east coast, atmospheric patterns during El Niño typically drive extratropical storms closer to the coast. They also change wind patterns which push water higher along the coast. This creates a combination of higher sea levels and a higher frequency of storm surges.

What kind of impact might I expect along the coast?

  • Due to the topography of the northeast (less low lying areas), high tides alone will not likely cause a significant impact on the coast unless accompanied by storm or strong winds.

Where might I expect high tide flooding?

  • Kings Point, NY; Providence, RI

Have a photo that shows coastal flooding in your region? Send it to us!

shadow for text box
flooded street in Alexandria, VA

This year’s report summarizing the high tide flooding events in 2017 and our high tide flooding outlook for 2018 is now available. The latest report is based on new, national flooding thresholds. It focuses on more impactful, deeper floods at some locations and expands the outlook to about 100 coastal locations.

Quick Links

Regional outlook (Text only)

Northeast outlook

Includes Maine, New Hampshire, Massachusetts, Connecticut, and New York

When will the tides be higher than normal?

  • September 9 - 11
  • October 8 - 10

Why will they be higher than normal?

  • Mean sea level is generally higher in the early fall months in the northeast due to warmer, expanding ocean water and changes in weather patterns.
  • A perigean spring tide will be occurring. This is when the moon is either new or full and closest to earth. Higher than normal high tides and lower than normal low tides will occur.
  • An El Nino is forecasted to begin strengthening in the fall. Along the east coast, atmospheric patterns during El Niño typically drive extratropical storms closer to the coast. They also change wind patterns which push water higher along the coast. This creates a combination of higher sea levels and a higher frequency of storm surges.

What kind of impact might I expect along the coast?

  • Due to the topography of the northeast (less low lying areas), high tides alone will not likely cause a significant impact on the coast unless accompanied by storm or strong winds.

Where might I expect high tide flooding?

  • Kings Point, NY; Providence, RI

Mid-Atlantic outlook

Includes New Jersey, Delaware, Pennsylvania, Maryland, District of Columbia, Virginia

When will the tides be higher than normal?

  • September 8 - 10
  • October 8 - 10

Why will they be higher than normal?

  • Mean sea level is generally higher in the early fall months in the Mid Atlantic due to warmer, expanding ocean water and changes in weather patterns.
  • A perigean spring tide will be occurring. This is when the moon is either new or full and closest to earth. Higher than normal high tides and lower than normal low tides will occur.
  • An El Niño is forecasted to begin strengthening in the fall. Along the east coast, atmospheric patterns during El Niño typically drive extratropical storms closer to the coast. They also change wind patterns which push water higher along the coast. This creates a combination of higher sea levels and a higher frequency of storm surges.

What kind of impact might I expect along the coast?

  • Minor tidal flooding along the coast, in particular in low-lying areas.
  • If a storm occurs at this time, increased levels of tidal flooding and coastal erosion may occur.
  • Lower than normal low tides will also occur.

Where might I expect high tide flooding?

  • Tide stations at the following locations have the greatest chance of seeing high tide flooding - Bergen Point, NY

Southeast outlook

Includes North Carolina, South Carolina, Georgia, Eastern Florida coast

When will the tides be higher than normal?

  • September 7 - 10
  • October 7 - 10

Why will they be higher than normal?

  • Mean sea level is generally higher in the fall in the Southeast due to changing weather patterns and typical short-term decreases in Gulf Stream transport.
  • A perigean spring tide will be occurring. This is when the moon is either new or full and closest to earth, higher than normal high tides and lower than normal low tides will occur.
  • An El Niño is forecasted to begin strengthening in the fall. Along the east coast, atmospheric patterns during El Niño typically drive extratropical storms closer to the coast. They also change wind patterns which push water higher along the coast. This creates a combination of higher sea levels and a higher frequency of storm surges.

What kind of impact might I expect along the coast?

  • Minor tidal flooding along the coast, in particular in low-lying areas.
  • If a storm occurs at this time, increased levels of tidal flooding and coastal erosion may occur.
  • Lower than normal low tides will also occur.

Where might I expect high tide flooding?

  • Tide stations at the following locations have the greatest chance of seeing high tide flooding - Myrtle Beach, SC; Charleston, SC; Fort Pulaski, GA; Fernandina Beach, FL

Gulf Coast outlook

Includes Texas, Louisiana, Mississippi, Alabama, Western Florida coast

When will the tides be higher than normal?

  • The Gulf Coast will not be significantly impacted.

Why won’t they be impacted?

  • In many locations of the Gulf Coast, the tidal range is relatively small compared to other regions of the U.S, so they will not be as significantly impacted by a perigean spring tide.

West Coast outlook

Includes California, Oregon, Washington State

When will the tides be higher than normal?

  • September 7 - 9
  • November 23 - 25

Why will they be higher than normal?

  • Mean sea level is generally higher in the early fall months along the southern west coast due to warmer, expanding ocean water and changes in weather patterns.
  • A perigean spring tide will be occurring. This is when the moon is either new or full and closest to earth. Higher than normal high tides and lower than normal low tides will occur.
  • An El Nino is forecasted to begin strengthening in the fall. Along the west coast, sea levels are typically elevated during El Niño.

What kind of impact might I expect along the coast?

  • Minor tidal flooding along the coast, in particular in low-lying areas.
  • If a local storm or large swell are present at this time, increased levels of tidal flooding and coastal erosion may occur.
  • Lower than normal low tides will also occur.

Where might I expect high tide flooding?

  • Tide stations at the following locations have the greatest chance of seeing high tide flooding - San Diego, CA (in Sep); Toke Point, WA (in Nov)

Hawaii and the Pacific Islands outlook

Includes Hawaii, Guam, American Samoa, Midway, Kwajalein, and Wake Island

When will the tides be higher than normal?

  • September 9 - 10

Why will they be higher than normal?

  • A perigean spring tide will be occurring. This is when the moon is either new or full and closest to earth. Higher than normal high tides and lower than normal low tides will occur.

What kind of impact might I expect along the coast?

  • Minor tidal flooding along the coast, in particular in low-lying areas.
  • If a local storm or large swell are present at this time, increased levels of tidal flooding and coastal erosion may occur.
  • Lower than normal low tides will also occur.

ALASKA outlook

When will the tides be higher than normal?

  • November 23 - 25

Why will they be higher than normal?

  • A perigean spring tide will be occurring. This is when the moon is either new or full and closest to earth, higher than normal high tides and lower than normal low tides will occur.
  • An El Nino is forecasted to begin strengthening in the fall. Along the west coast, sea levels are typically elevated during El Niño.

What kind of impact might I expect along the coast?

  • Due to the topography, in particular for southeast Alaska (less low lying areas), tidal flooding will generally not have a significant impact on the coast unless there is a severe storm.