Strong southward winds and new moon may cause east coast USA flooding

By: Dr Larry P. Atkinson , 2:46AM,GMT on January 2,2016




 

A combination of new Moon on January 9th, strong winds from the north and a coastal low off the SE US starting on the 4th may lead to coastal flooding at various locations from the mid-Atlantic to the east coast of Florida.

Let’s watch this play out and see where the flooding occurs.

The location of wind induced flooding depends on the wind direction. Off the east coast the optimum wind for coastal flooding is equatorward and parallel or slightly onshore. Thanks to Coriolis force water moves to the right of the wind in the northern Hemisphere. Thus a southward wind off Virginia ‘pushes’ water onshore and will cause coastal flooding while the same southward wind off Long Island will not: the angle of the wind relative to the angle of the coastline is important.



Figure 1. This figure is taken from earth.nullschool.net. You can see the predicted low off the SE and the wind streaming at different angles to the coast from Maine to Florida. If this prediction holds up we can expect flooding in the Virginia Beach/Norfolk area (green circle) and along the South Carolina coast and farther south. Any changes in wind direction will alter the areas of flooding. Also winds need to be above 10 m/s (20 knots) to be effective.



Figure 2. This is the water level prediction for the 4th as calculated on the 1st. The prediction now is for slightly above highest astronomical tide (HAT). In the Norfolk area this causes minor street flooding. This is recalculated several times a day and will change as the wind predictions change. Data from http://nws.weather.gov/mdlsurge/etsurge2.0esri

Feel free to post pictures with time stamps and location if you wish.