Thursday, July 3, 2014

Hurricane Arthur Bears Down on North Carolina

Hurricane Arthur was bearing down on North Carolina this evening as a category-1 hurricane with maximum sustained winds of 90 mph, according to the National Hurricane Center. They predict that Arthur may intensify to a category-2 hurricane at landfall or it's closest approach to the coast.

Hurricane Arthur's eye is clearly visible just southeast of Wilmington, North Carolina, on this radar image provided by Weather Underground's WunderMap. The National Hurricane Center said Arthur's eyewall was just east of Cape Fear.

The National Hurricane Center forecasts that storm surge could inundate land areas, reaching the following heights if the timing of peak surge occurs at high tide:

3-5 feet above ground level in the coastal areas of North Carolina within the hurricane warning;
2-4 feet above ground level in Pamlico and Albemarle Sounds;
1-3 feet above ground level in Southern North Carolina and Northeastern South Carolina;
1-3 feet above ground level in Extreme Southeastern Virginia.

Keep in mind, those are not storm surge heights above mean sea level, but actually above ground level. 

Extensive storm surge history is available for North Carolina, as this region is familiar with visits from hurricanes and tropical storms. The Program for the Study of Developed Shorelines at Western Carolina University has developed an extensive dataset, as well as an interesting fact sheet about historic storm surges in North Carolina. This page is called, Cataloging all Available Storm Surge Measurements for the State of North Carolina: The National Storm Surge Database, and is available on the Web at: https://shoreline.wcu.edu/Katie/SS_SEGSA_2011.pdf.

 The Program for the Study of Developed Shorelines at Western Carolina University has developed extensive storm surge data and mapping capabilities, as well as useful information about past surges in North Carolina

This website shows the capabilities of their database combined with GIS mapping, which enables them to consider how storm surge is affected by various hurricane parameters, like hurricane track and angle of a hurricane's approach to a coastline. In regards to North Carolina storm surges, they provide a top 10 list of high water marks available in their dataset, including the following observations, which were the highest in North Carolina for each of these hurricanes:

Storm Name    Year    High Water Mark (ft)      Location
Hazel               1954              18                       Brunswick
Isabel              2003              16.2                     Dare
Fran                1996              15.4                     New Hanover
Ione                1955              15.1                     Craven

Western Carolina University's National Storm Surge Database project has developed various technological tools, including a Storm Surge Viewer and other products that enable users to view storm surge observations and hurricane tracks.

The Southern Climate Impact Planning Program (SCIPP) has also developed extensive storm surge data for North Carolina. So far, SCIPP has identified 989 storm surge observations in the state. These data are provided for 46 separate tropical cyclones since 1857.

SCIPP has also developed mapping work that provides historical storm surge/ storm tide heights, as well as the tracks of historic hurricanes that produced such high water marks. For example, the image below is a SCIPP map of Hurricane Hazel's track and high water marks in 1954. This map is not intended to be a comparison to Arthur's storm surge in any way, but rather a snapshot of the capabilities of this database and mapping work.

 SCIPP map of Hurricane Hazel's track and storm surge/ storm tide observations in 1954. According to the Program for the Study of Developed Shorelines at Western Carolina University, Hazel's 18-ft storm surge was the highest in the history of North Carolina.



1 comment: