Thunderstorm activity associated with the area of low pressure off the east coast of Florida has increased and become a little more organized during Monday evening. Radar data shows that the storms have developed in a band around the southeastern and southern portions of the circulation. Based on this, ADVISORIES have been initiated on the first tropical depression of the 2014 Atlantic hurricane season.
The south to southwest motion of the system over the past couple of days seems to have slowed. The initial motion is to the southwest at 2 mph. The computer model guidance indicates that the depression should begin to move slowly westward overnight and early Tuesday. After that time, the system will begin to be steered to the northwest and then northward. A large weather system approaches the east coast of the U.S. from the west in a couple of days and should turn the system to the northeast and cause it to accelerate. The model guidance is in good agreement on this scenario, but there is still significant uncertainty on how close the system will get to the coast of the southeastern U.S.
Conditions will be favorable along the forecast track for gradual strengthening during the next few days. The depression is forecast to become a tropical storm on Tuesday and would be named Arthur.
Interests along the east coast of the southeastern United States (including eastern North Carolina) should monitor the progress of this system.
Satellite and radar pictures indicate that the showers and thunderstorms associated with the low pressure area located about 90 miles east of Vero Beach, Florida, have changed little in organization during the last few hours.
We have seen a couple of clusters of thunderstorms blow up in the past hour and this could be the beginning of a more "closed" circulation. Right now, the north side of the system is drawing in dry air from the north that is hampering development, but environmental conditions continue to be favorable for development.
Only a slight increase in the organization and persistence of the thunderstorm activity wold result in the formation of a tropical depression.
The low is moving southwestward at about 5 mph but is expected to turn westward tonight and northward by Wednesday as it moves near the east coast of Florida.
The National Hurricane Center says the system has an 80% chance of becoming a tropical depression i the next 48 hours.
An Air Force Reserve unit reconnaissance aircraft investigated the area low pressure that is now about 110 miles east of Melbourne, Florida, this afternoon. While the low pressure is well defined in satellite and radar pictures, the associated thunderstorm activity is just below the organizational threshold criteria required to be classified as a tropical depression or tropical storm.
Environmental conditions continue to be favorable for development and only a slight increase in the organization and persistence of thunderstorm activity would result in the formation of a tropical depression (38 mph wind and a "closed" circle of thunderstorm activity at its center).
The data from the reconnaissance flight indicate that peak sustained winds with the low are about 30-35 mph. The low is moving southwestward at around 5 mph, but is expected to turn westward tonight and then northward by Wednesday while moving near the east coast of Florida. A turn toward the northeast near the southeastern US coast is expected by Thursday.
Just in time for the Fourth of July holiday weekend, the first tropical system of the year could be impacting our coast.
This will be a slow development, through the first part of this week. It is currently a disorganized area of thunder storms east of Miami, Florida, heading southward. However; forecast models show this developing into our first named system of the year, which would be Arthur. The storm is forecasted to turn northwest, then north by midweek as it tracks along the southeastern U.S. coast. By the end of the week it will likely be headed our way tracking right along or just off of our coast.
The organizing low pressure system is now roughly 160 miles east of Daytona Beach and will slowly becomes stronger as it drifts south. Upper level winds are only marginally favorable for development but will improve by mid week so a storm could fully develop within the next day or two. The storm needs to develop first before we start talking about specific impact on us here in Eastern Carolina. The key to development and the ultimate track will be the storm system in the western Great Lakes. As this system plows eastward it will begin to pull our developing tropical system northward along the southeastern U.S. coast.
Stay with us this entire week as we track Arthur-to-be and it's potential impacts on our holiday weekend here in Eastern Carolina.