All Weather News

High Tide Bulletin: Fall 2016

19 Sep 2016, 6:53 am

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. About three or four times a year (in the spring and the fall), the new or full moon coincides closely in time with the perigee of the moon—the point when the moon is closest to the Earth. These occurrences are often called ‘perigean spring tides.’ There are some factors we can predict that cause the tides to be higher or lower than what is “normally” seen from day to day. Here’s a look at who may experience higher than normal high tides for September, October and November:

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GULF COAST
When will the tides be higher than normal?
In September, October, and November, the Gulf Coast water levels will not be significantly impacted by the Perigean Spring Tide.

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 the perigean spring tide. However, in the fall, non-tidal impacts in the Gulf such as adverse weather may cause flooding.

SOUTHEAST OUTLOOK
When will the tides be higher than normal?
September 18-20, October 15-20, November 13-17

Why will they be higher than normal?
A perigean spring tide will be occurring. Mean sea level is generally higher in the fall in the Southeast due to changing weather patterns and a decrease in Gulf Stream transport.

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.

MID ATLANTIC OUTLOOK
When will the tides be higher than normal?
September 18-20, October 16-19, November 14-16

Why will they be higher than normal?
A perigean spring tide will be occurring. 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.

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.

NORTHEAST OUTLOOK
When will the tides be higher than normal?
October 16-28, November 14-16

Why will they be higher than normal?
A perigean spring tide will be occurring. 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.

What kind of impact might I expect along the coast?
Due to the topography of the northeast (less low lying areas), tidal flooding will generally not have a significant impact on the coast unless there is a severe storm.

WEST COAST OUTLOOK
When will the tides be higher than normal?
October 17-18, November 13-17

Why will they be higher than normal?
A perigean spring tide will be occurring. Higher high tides occur on the West Coast in the late fall due to the increased angle of the sun relative to the Earth, which reaches a maximum during the Winter Solstice (December 21).

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.

FULL MOON

NOAA’s seasonal tide bulletins lets you know when you may experience higher than normal high tides. However, higher than normal high tides alone do not necessarily cause coastal flooding. Be aware that nuisance flooding is more likely to occur during these periods depending on your location along the coast. More severe flooding may also result if adverse weather conditions are present, such as heavy rains, strong wind, or big waves.

The information provided in this article is courtesy of NOAA’s Fall 2016 High Tide Bulletin.

For WeatherNation, Meteorologist Karissa Klos

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