Coastal Forecast *Hurricane* Arthur

Okay ladies and gentlemen this is it! The forecast you've all been waiting for! I currently have friends and family in Oak Island, Wilmington/Wrightsville Beach, Atlantic Beach, and Ocracoke Island so I will make a forecast for each location estimating rainfall, storm surge, wind speed, estimated time of arrival, and duration of Hurricane Arthur for each location. See the beaches in order of Landfall below.

Holden Beach/Ocean Isle/Sunset Beach/Oak Island

The Southeastern Beaches of NC will experience the force of Hurricane Arthur before the rest of the state. This area is currently under a Tropical Storm Warning, since Hurricane Arthur will not actually be making landfall, the eye wall (area with strongest wind speed) will not be hitting this portion of NC. People living in this area can expect to see sustained winds of around 50 kts (~58 mph) with gusts reaching the triple digits. Rain will vary depending on whether the hurricane meets up with the cold front currently moving across our state or not but if so, beach-goers can expect to see around 2-3 inches of rain. The potential storm surge in this area could be around 3 feet above ground, but since the elevation of the region is around 20 feet above sea level, that surge could be diminished. Nonetheless, If you have anything on the ground floor in your garages, it would be good to move those into the house where they will stay dry. The center of the storm is currently about 6.5 degrees lat south and about 1 degree west long moving north-northeastward at about 10 mph. This means that the highest storm surge will be experienced at around 5:00 p.m. and the strongest wind and rain will be experienced around 11:00 p.m.. The storm will likely last around 20 hours (including what has already been experienced), so the fourth of July plans shouldn't be postponed for this area.

It is safe to ride out the storm in this area.

Wrightsville Beach

Both the Holden Beach area and the Wrightsville Beach area are already experiencing some of Arthur. Wrightsville Beach should expect wind speeds around 60-65 kts (69-74 mph) with gusts coming later this evening near 80 mph. Those living in the Wrightsville Beach/Wilmington area can expect around 3-4 inches of rain in the next 36 hours. Storm Surge for Wrightsville Beach/Masonboro Island is predicted at around 4-5 feet, and the Wilmington area surrounding the Cape Fear River should see around 3 feet of storm surge. It would be a good idea to move items into higher areas. The highest storm surge of Arthur should be around 7:00-7:40 p.m. and the highest winds will likely occur around and after midnignt. Arthur should move out of the area by around breakfast time.

It is probably safe to ride out the storm on Wightsville Beach, but I would not recommend it. If you live on the Wilmington mainland, you should be okay.

Atlantic Beach

Atlantic Beach will be the first point of landfall for the eye of Hurricane Arthur. Wind speeds of up to 90 mph can be expected in this region on the back side of the eye wall and storm surge will be around 6-7 feet. The highest surge and strongest winds will both be experienced around 3:00-4:00 tomorrow morning (July 4th) as that is when the eye is going to make landfall on the island. The storm should last around 30-36 hours. The Fourth of July festivities have been postponed until 5:00 p.m. on Saturday, July 5th.

I would highly recommend evacuating this area, as the combination of storm surge and wind speed could provide for devastating effects.

Ocracoke Island

Ocracoke Island shouldn't experience the same force as Atlantic Beach. Though the eye will pass over Ocracoke Island, the surge will not be quite as bad. Surge will probably still be between 3 and 6 feet in some places, but generally the surge will be lower than 3-4 feet. The sustained wind speeds and gusts will be about the same as Atlantic Beach with sustained winds between 75-80 mph and gusts up to 90, and Ocracoke can expect between 3-4 inches of rain. These will be experienced just an hour or two after Atlantic Beach and can be expected between 4:00-6:00 tomorrow morning. The storm will last until the early afternoon. The Fourth of July festivities have been postponed until 5:00 p.m. on Saturday, July 5th.

It should be safe to ride out the storm but I am not promising that your house will not get very wet.

Extra Important Information

Be careful of Tornadoes! Many times the damage of hurricanes comes from tornadoes embedded inside the walls of the hurricane and can be accompanied by hail and heavier rain. Stay tuned to your local weather stations as often and for as long as you can if you decide to ride out the storm!

If you have any questions about storm surge, visit this site and click continue. This storm surge map is "experimental" and is being used to estimate surge for locations in the path of the hurricane based on numerous mathematical formulas and derivations.

http://www.nhc.noaa.gov/refresh/graphics_at1+shtml/154057.shtml?inundation#contents

Tropical Storm Arthur

Does anyone remember the show from the 90's? Yeah, I remember growing up with Arthur as one of the cartoons I watched on a regular basis. This Arthur however is far from a cartoon.

The first named storm of the 2014 Atlantic Hurricane Season is Tropical Storm Arthur. Currently packing sustained winds of 35-45 knots with gusts reaching 55 knots at times, Arthur is located 3 degrees east of the Florida/Georgia border and is currently moving N. It is expected to turn more toward the NE and hit the Outer Banks of NC as the Primary Landfall point before continuing up the East Coast. It is possible that this storm could become a Cat 1 Hurricane before making landfall. Regardless of the meteorological categorization, we will experience hurricane force winds in the outer banks should Arthur continue on it's NNEward path. I am considering driving out Thursday night after work so that I can grab some pictures and videos from the beach to post! And because it would be fun haha!

We also have a Tropical Storm in the Eastern Pacific, Tropical Storm Douglas, which will continue NWward into the mid-Pacific Ocean.

So, why was Tropical Arthur able to form? Don't Hurricanes form off the coast of Africa and move in a semicircle path, or form in the gulf and die over the US? Not exactly. There are six factors which contribute to hurricane formation:
1. SST (Sea Surface Temperature) needs to be greater than 80 degrees Fahrenheit for optimal Hurricane formation
2. Easterly Wave or perturbation needs to occur to begin rotation off the coast of Africa
3. Low Wind Shear
4. A convectively unstable atmosphere
5. Sufficient low-level moisture for entrainment or feeding the hurricane
6. Coriolis greater than 5 degrees from the equator. Coriolis is one of the main atmospheric forces when balancing atmospheric rotation and movement of air, and gets stronger with increased speed, rotation, or distance from the equator. The two other forces balanced by Coriolis Force are Pressure Gradient Force and Friction.

When hurricanes form in the Western Atlantic or Gulf of Mexico, the Easterly Wave is not the cause of hurricanes. Typically it's as a result of the Continental Low being trapped between the Bermuda High and the Canadian High pressure systems. This is exactly what happened with Tropical Storm Arthur. The rotation of the Continental Low just off the coast of Florida was accelerated by the Canadian High to the Northeast, and the Bermuda High to the Southwest. The rotation acceleration and stationary location over the warm mid-tropical Atlantic waters allowed for a rapid intensification of the Low. Above is the National Forecast Map for June 30, and it is clear that the High Pressure systems are accelerating the Low. The Low rotates counterclockwise, and each of those four Highs are rotating clockwise. That Low meteorologically is trying to get back to it's normal position over the Southeastern United States, but the four High Centers kept it from moving back and accelerated the rotation. Now, the Tropical Storm is moving up the East Coast and following the Gulf Stream and trade winds and will continue until it dies out.

More accurate information will come tomorrow as the track is easier to forecast 24 hours out. I will have more of a forecast post instead of an informational post tomorrow. If you live on the coast, shopping wouldn't be a bad idea! Power shouldn't go out but with weather, anything can happen.