The water level along the coast of Long Island Sound and other areas changes from hour to hour and day to day for a variety of reasons.  Usually the most obvious water level variations are created by astronomical high and low tides generated by the gravitational pull of the sun and moon.  Storms with strong winds also can raise or lower water levels throughout the Long Island Sound as the storms move through our area or pass by offshore.  These storm-driven water level changes are often referred to as storm surge.  Storm surge can cause coastal water level to be above or below the normal astronomical tide levels.  Coastal flooding can occur when the water level is raised above the normal astronomical high tide for the day.  Heavy rains also can cause flooding along rivers during the rain event and for the next several days.

The scientific community now can predict coastal sea level much like weather forecasts, but with with similar limitations.  Sea level variations from astronomical tides are predicted many months in advance with extremely high certainty.  Storm surge and river flooding can be predicted several days in advance, but they depend on accurate wind and precipitation forecasts, respectively.  Both are sensitive to the exact timing and path of storm arrival, which is particularly hard to accurately predict more than a few days in advance.  This uncertainty is a limitation for coastal flooding forecasts since the amount of flooding depends on the timing of maximum surge or river flood waters relative to high tide.  In light of these considerations, it is important to keep in mind that the accuracy of the coastal sea level prediction typically decreases (and the uncertainty increases) for forecasts farther into the future.

The coastal sea level forecasts presented below are based on the NOAA ExtraTropical Storm Surge Model (known as ET-SURGE and ETSS).  These forecasts include astronomical tides and storm surge, but do not include precipitation-driven river flooding.  Though this an is operational forecast system, the presentation of results on this webpage are intended for educational purposes only.  Furthermore, NOAA does not rely on ET-Surge for predicting flooding related to hurricanes and other tropical storms; instead advisories and warnings are issued by the NOAA National Hurricane Center using a combination of forecast products.

Primary ET-SURGE stations:

 

Primary and derived stations:

Station	Latitude	Longitude
Silver Eel Pond (Fishers Island)	41.2567	-072.0300
New London	41.3614	-072.0900
Niantic	41.3250	-072.1867
Saybrook Jetty	41.2633	-072.3433
Westbrook	41.2733	-072.4750
Clinton	41.2683	-072.5317
Madison	41.2700	-072.5900
Guilford Harbor	41.2717	-072.6667
Sachem Head (Guilford)	41.2450	-072.7083
Branford	41.2617	-072.8183
Lighthouse Point (New Haven)	41.2517	-072.9050
New Haven	41.2833	-072.9083
Gulf Beach (Milford)	41.2050	-073.0417
Milford Harbor	41.2183	-072.0550
Sniffens Point (Stratford)	41.1867	-072.1133
Bridgeport	41.1733	-072.1817
Black Rock Harbor (Bridgeport)	41.1567	-072.2133
Southport	41.1333	-072.2833
South Norwalk	41.0967	-072.4150
Rowayton (Norwalk)	41.0650	-072.4450
Long Neck Point (Darien)	41.0383	-072.4800
Stamford	41.0383	-072.5467
Cos Cob (Greenwich)	41.0167	-073.5967
Kings Point (Long Island)	40.8103	-073.7649

 

 

 

 

 

 

 

 

ET-SURGE Graphs from NOAA Website:

 

ESTOFS: