12:30 PM | ***Hurricane threat for the Outer Banks and heavy rain coming here from later Wednesday into Friday***
[Latest NOAA GOES East visible satellite image of Tropical Storm Arthur]
First the good news…Saturday and Sunday look like they’ll be quite nice in the Mid-Atlantic region with plenty of sunshine and pleasant temperatures. Now the bad news…there will be heavy rain to deal with around here before we get to the weekend as a strong slow-moving frontal system interacts with tropical moisture along the east coast from what is likely to become the first hurricane of the season.
Sea surface temperatures (SST) continue to run at warmer-than-normal levels (see latest SST anomaly map below) off the east coast of the US and this may result in more “home-grown” type systems this tropical season that develop close by as compared with the “African-wave” type of tropical system that travels a long distance across the Atlantic Ocean. Indeed, a tropical disturbance meandering off the east coast of Florida has intensified into tropical storm status (named Arthur) over the unusually warm waters off the southeast US coastline. This system will likely reach hurricane status by the time it reaches the Outer Banks of North Carolina later Thursday into early Friday. Arthur is the latest first named tropical storm since 2004 when Alex formed on July 31st and that storm coincidentally took a track quite similar to what this one is likely to do.
[Unusually warm waters off the Southeast coastline]
A strong cold front from the middle of the country will slowly close in on the east coast during the next couple of days and - as tropical moisture interacts with the front - heavy downpours are likely to break out along the I-95 corridor from DC-to-Philly-to-NYC in the time period from later Wednesday into Friday. After Arthur directly impacts the Outer Banks, it will likely push northeastward to the east of the Mid-Atlantic coastline on the 4th of July (Friday) on its way to the New England coastal waters by late Friday night/early Saturday. This timing and current estimated storm track should allow for nice weather to return to the Mid-Atlantic region on Saturday and Sunday although rough surf may linger for awhile in the Atlantic Ocean.