Surge is the rise in water levels above normal due to the action of wind stress upon water. Learn more about surge at National Hurricane Center website. Technical paper 48, Characteristics of the Hurricane Storm Surge by Harris (1963) provides documentation about the surge from many hurricanes.
|Graphical computation of the storm tide hydrograph from the addition of the SLOSH and tide hydrographs at two locations. The peak of the storm tide hydrograph is compared to the observed height. (Source: Jarvinen, 2006. Storm tides in Twelve Tropical Cyclones (including four intense New England Hurricanes). National hurricane center.)|
New England hurricanes are typically fast moving storms and so the tidal surge is typically short-lived. In contract, nor'easters are often slow moving storms and their surge tends to affect shorelines for several days. The Patriot's Day storm of April 19th, 2007 is an example of a nor'easter and the Maine USGS has a description of this storm and associated shoreline changes.
A tropical cyclone climatology can be found at the National Hurricane Center.
NOAA Video about Surge:
Real-time Storm Surge:
Real-time storm surge can viewed at various tide gauge station. These typically show astronomical predictions versus real-time observations. The majority of tide gauges in New England are maintained by NOAA but the USGS (11?) and the Corps of Engineers (4) provide real-time tide gauge data.
NOAA gauges can be accessed via NOAA or NERACOOS.
USGS gauges can be accessed via nowCOAST. Select northeast, river, gage height, and realtime to select all of the USGS stream gages. Some of the downstream gages are tide gages.
Northeast COE gauges, gauge locations include:
- Stamford, CT - hurricane barrier
- New Bedford, MA - hurricanes barrier
- Haverill, MA - tidal stream gauge
- Connecticut River @ Hartford, CT - tidal stream gauge
- Connecticut River @ Middletown, CT - tidal stream gauge
Webcams are means to actually see present conditions along the coast and waterways. Two comprehensive sources for the Northeast include:
- nowCoast - select the "Northeast" tab at the top and hit the "GO" butteon and then select (check) webcams in the table of contents on the right under the category "Observations - Remote sensors"
- coastal webcams for Maine to Connecticut at Maine Harbors
The NERACOOS Model Forecast / Observation Viewer is designed to permit comparing model forecasts against actual observation for both wave height and water levels.
NOAA NWS Extratropical Storm Surge (Northeast US) is produced by the NWS Meteorological Development Laboratory. Various forecast intervals out to 96 hours.
|The 48-72 hour forecast shows Montauk station at surge and by selecting the station - a graphical representation of the forecast appears showing surge developing on Saturday and continuing through Sunday.|
NOAA Ocean Prediction Center - Surge Forecast 96 hour loop (northeast)
STORMY - Stony Brook Storm Surge Research Group.
|Surge forecast for the New London, CT tide station during the December 12, 2009 nor'easter.|
|The topmost figure shows the tide gauges for southern New England and the lower graph shows the astronomical tide predictions versus the forecast model for the New London tide gauge. The surge is for a nor'easter that will arrive on February 10, 2010.|
NWS Riverforecast: The Advanced Hydrologic Prediction Service provides real-time information on river stage and some stations have forecast predictions. Some of these stations are tide gages at mouth of rivers. In the example below observed and forecast values are provided and the flood stage and moderate flood stage forecasts are shown for Bridgeport Harbor.
|River forecast relative to NAVD88 for a coastal 'river' gauge. The flood stages are different than values derived from the Corps of Engineers Tidal Flood Profiles of New England.|
For more riverine but tidal rivers such as the Connecticut River, additional flood data are available (e.g., Hartford, CT) such as the "chance of exceeding levels during the entire period" which include descriptions of flooding impacts depending upon flood stage.
LISICOS Surge Model for Long Island Sound. A surge model for is under development for Long Island Sound. A surge animation is for southeastern Connecticut is a available for importing into and viewing within Google Earth. This model incorporates inundation of the land surface based upon a 2006 high resolution LIDAR digital elevation model. Unfortunately, the base maps in Google Earth currently lack the resolution to visualize the surge flooding in detail. Click here to download KML file for Hurricane Gloria. This model has been developed by Todd Fake and James O'Donnell at the University of Connecticut.
|The arrows correspond to the current direction and velocity and the water colors correspond to water height. This is a snapshot for the time segment at the peak of the surge on the CT shoreline.|
DalCoast Surge Forecast - Available through the Dalhousie Coastal Ocean Prediction System. This is an experimental system with forecasts prepared once a day.
|Storm surge forecast for Halifax (no tides).|
Coastal Flooding and Erosion Forecast model.
GoMOOS has worked with meteorologists at the National Weather Service in Gray, Maine to prototype a decision-support tool for NERACOOS that predicts coastal storm damage. The tool uses forecasts of water level and waves to predict coastal damage near Saco, Maine. A prototype was recently adapted to Scituate, Massachusetts and is being validated with storm data from the weather service and local emergency management community.
The Coastal Flooding and Erosion Forecast is now available in real-time for the following locations: Scituate and Portland.
An empirical relationship exists between storm tide, waves and coastal flooding or splash-over damage which allow us to predict when flooding and splash-over events (such as beach erosion) might occur based on forecast water level (tide height) and wave height data. The red line (horizontal) represents the point at which the water level is at flood stage (FS). A yellow line (slight diagonal left to right) represents when splash over begins. Progressively darkening horizontal bands (light orange to red), represents when minor, moderate and severe coastal flooding will occur. When the nomgram is in motion, a real-time indicator moves through the 48 hour forecast as a series of red circles. The leading circle of the indicator represents the most recent reading, and the trailing circles are previous readings (in 1 hour increments). Visit animation samples at NERACOOS and access the links to Scituate and Portland, Maine.
|A snapshot of forecast model showing splashover beginning when the wave height has reached 10 feet.|
Sea, Lake and Overland Surges from Hurricanes (SLOSH)
SLOSH is a model developed by the National Weather Service to estimate storm surge heights and winds resulting from historical , hypothetical or predicted hurricanes. SLOSH is the primary model used by NWS, the Corps of Engineers, and Emergency Managers. It is also the basis for hurricane evacuation studies. Probabalistic hurricane storm surge graphics are generated by the National Weather Service's Meteorological Development Laboratory. A training manual is available at the FEMA website. According to this manual, the primary purposes of SLOSH are:
- SLOSH is best used for defining the potential flooding from storm surge for a location from a threatening hurricane, rather than as a predictor of the specific areas that will be inundated during a particular event.
- SLOSH output is used as the hazard analysis for hurricane evacuation plans. SLOSH model results are combined with traffic flow information for creating a HES and combined with rainfall amounts, river flow, or wind-driven waves to determine a final analysis of at-risk areas.
Hurricane Evacuation Study data which include surge projections from SLOSH are available in adobe pdf format from the FEMA/COE Comprehensive Hurricane Data Preparedness Study Web Site.
SLOSH was used to recreate the hurricane surge from 12 U.S. hurricanes including four intense New England hurricanes specifically the Great Colonial Hurricane of 1635, the Great September Gale of 1815, the 1938 New England Hurricane and Hurricane Carol of 1954.
Hurricane 1954 Surge Survey.
In 1957/1958, the Corps of Engineers conducted a survey throughout southern New England to determine the elevation of the surge from Hurricane Carol (1954). This was an opportunistic survey in that other high water marks from Hurricanes such as 1938 and 1944 were recorded. The Coastal Hazards Working Group of the Northeast Regional Ocean Council is conducting a pilot study to extract these data from paper files and create an access database and GIS coverage for Connecticut. The University of Connecticut will use these data to assess their accuracy of the surge model described above. Through the recreation of the atmospheric conditions associated with these storms, the model outputs will be compared to the survey data to assess the accuracy of the model. If this pilot is determined to be useful for Coastal Hazards, NROC will determine an approach to populate the database/GIS with the Rhode Island and Massachusetts data. The Connecticut Department of Environmental Protection, Office of Long Island Sound Programs is the lead for the pilot project.
|Elevation in feet (NGVD1929) of surveyed high water marks from Hurricane Carol (1954) in New London and Groton, CT.|