1:15 PM (Wed.) | ****Tropical/sub-tropical coastal storm threat continues for the eastern Mid-Atlantic region…heavy rain, gusty winds likely on Friday with strong rip currents in the ocean****
Paul Dorian
Circulation is becoming more noticeable around low pressure now over coastal South Carolina. There is a lot of moisture feeding into the developing storm in its eastern side with numerous showers and thunderstorms visible on satellite and radar imagery. Imagery courtesy College of DuPage, NOAA
Overview
Scattered showers and thunderstorms continue to plague the Mid-Atlantic region at mid-day and this threat will continue into tonight. On Thursday, attention will turn to the Outer Banks region of North Carolina as this is where low pressure is likely to be located early in the day. This system is then likely to push to the northeast out over the warm waters of the western Atlantic and then make a move northward reaching a position near the southern part of the Delmarva Peninsula by early Friday. There is a chance when this system moves over the open waters of the western Atlantic, it’ll intensify enough to become a “named” tropical storm by NOAA’s National Hurricane Center. Whether or not it becomes a "named" storm (it would be “Fay”), it has the potential to produce very heavy rainfall on Friday in the eastern part of the Mid-Atlantic region along with gusty winds and strong rip currents in the western Atlantic Ocean. The departure of this coastal storm on Saturday will likely not be the end of the wet weather pattern in the eastern US. An impressive upper-level trough should form by later in the weekend likely leading to more rainfall into the first half of next week.
Low pressure is likely to be situated near the Delaware/southern New Jersey coastal region by early Friday and it could produce some heavy rainfall and gusty winds for the eastern Mid-Atlantic. Map courtesy NOAA, tropicaltidbits.com
Details
High moisture levels continue to exist in the Mid-Atlantic region at mid-day and this is contributing to scattered showers and thunderstorms which are especially prevalent north of the PA/MD border. Any spot that is hit by a shower or storm later today can receive some heavy rainfall given the abundant moisture in the atmosphere. Grounds are well-saturated in many areas following the downpours of earlier this week so flash flooding is a concern throughout the Mid-Atlantic region and it will continue to be a concern for the late week coastal storm situation that is now unfolding.
NOAA’s National Hurricane Center (NHC) is keeping a close eye on this low pressure system over the Carolina coastline as it could intensify into a “named” tropical storm once it reaches the warm waters of the western Atlantic Ocean.
Another batch of showers and thunderstorms is currently located over the Carolinas and the western part of the Atlantic Ocean. This batch of rain is associated with a developing low pressure system that is getting organized near the North Carolina/South Carolina coastal border region. It is this system that will make a move to the northeast over the next 24 hours and it will likely reach a position near the southern part of the Delmarva Peninsula by early Friday. As such, very heavy rainfall is on the table for Friday in the eastern part of the Mid-Atlantic region and there can be flash flooding, gusty winds, and strong rip currents in the ocean.
The latest European model forecast goes all in for a very wet coastal storm on Friday with significant rainfall amounts predicted in the eastern Mid-Atlantic. Map courtesy ECMWF, pivotalweather.com
The high impact area from this unfolding coastal storm in terms of heavy rainfall could extend all the way inland to the DC metro region; however, it is more likely to extend from the Delmarva Peninsula-to-eastern Pennsylvania-to-New Jersey and northward to the New York City metro region. By the early part of the weekend, the coastal storm is liable to push northward into interior New York State and it’ll likely generate some decent rainfall to that part of the NE US and that likely will not be the end of the wet weather pattern for the eastern states.
The active and wet weather pattern of recent days for the eastern US is likely to continue well into next week as an impressive upper-level trough drops southeastward and deepens significantly. Map courtesy NOAA, tropicaltidbits.com
Looking beyond the coastal storm, an impressive upper-level trough will drop southeastward from the Great Lakes later in the weekend and intensify once it slides into the eastern US early next week. As a result, there will continue to be the threat for showers and thunderstorms for much of the eastern third of the nation as we progress through the first half of next week and given the already well-saturated grounds, flooding concerns will likely continue; especially, if the late week coastal storm results in the very heavy rainfall.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
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