The 2020 Atlantic hurricane season has been record-breaking, with five named storms already spinning up and putting on brief devilish dances as summer waxes and the oceans warm. Arthur sideswiped the Outer Banks of the Carolinas in May, while Bertha and Cristobal brought heavy rain to the Southeast and Gulf Coast. Now, a new tropical storm may be brewing, and is set to bring heavy rainfall, gusty winds, and perhaps a low-end tornado risk to parts of the Northeast into the weekend.
Places like New York, Hartford, Providence, and Boston will likely see heavy rain Friday into Saturday, with areas of flooding not out of the question in southern New England. That’s regardless of whether or not whatever materializes gets a name — but if it does, “Fay” is next up.
If Fay becomes a reality, it would become the earliest “F” storm on record. That would beat out the previous record for earliest sixth named storm – Tropical Storm Franklin, which formed on July 22, 2005 – by more than a week. On average, the first “F” name storm doesn’t form until September 8, about two months from now.
The system is disorganized right now, but could blossom by Thursday as it moves over exceptionally warm waters, several degrees warmer than normal, just offshore the North Carolina Outer Banks. Dubbed “Invest 98L,” the fledgling disturbance that could soon seed tropical cyclone development was located near the northeast coast of North Carolina early Wednesday. Meteorologists at the National Hurricane Center estimate it has a 70 percent chance of development.
Heavy rainfall was moving north-northeast, approaching the Outer Banks and Cape Hatteras on Wednesday morning. Most of the rain looks to miss inland areas, but places that jut out farther east — like Ocracoke, for instance — could pick up an inch or two of rain through Thursday. The heaviest will fall on Wednesday night.
Then the system will likely become better organized, possibly morphing into a tropical storm as it barrels farther north. Its western fringe should scrape the coastal Mid-Atlantic, likely bringing some downpours and thunderstorms to Delmarva and New Jersey late Thursday and Friday.
At the moment, the heaviest rain looks to mostly remain east of the Interstate 95 corridor from Richmond to Baltimore, but some showers are possible in these areas between Thursday night and Friday night.
The system, probably named Fay by that point, will carry with it an exceptionally moist air mass characteristic of the deep tropics. It’s likely that PWATs, or precipitable water indices, a measure of how much moisture is present in a vertical column of atmosphere, could approach 2.5 inches even into southern New England. That would approach record territory if realized, with the July maximum ever observed in Chatham, Massachusetts at 2.65 inches.
The National Weather Service in Boston summed it up best when they wrote “at this point, what we know is that with this kind of moisture plume someone is going to get a lot of rain. Where and when that is will have to be settled in the coming days.”
It’s unclear whether or not the system would be more tropical or subtropical in nature, the latter possessing a mixed bag of traits belonging to tropical cyclones and non-tropical mid-latitude lows.
Timing is a bit uncertain, with some models bringing a quicker dose of rainfall Friday into Friday night as others keep the system around into Saturday. How quickly the system moves will have a bearing on where it goes, a speedier system slipping out to sea but a slower one becoming captured by an approaching low pressure system to the west. The latter scenario would yank the storm – and its moisture — farther inland.
All told, a general 1 to 2 inches is a good bet for most of southern New England, including Connecticut, Massachusetts, and Rhode Island. Beneath the system’s axis of heaviest rainfall, which some models have shifted westwards, 2 to 4 inches or greater is possible.
There would also be a low risk of an isolated waterspout or brief tornado east of the system’s center.
Right along the coast, from Long Island to Cape Cod, winds could gust between 35 and 50 mph as the storm makes its closest approach.
Whether or not the system jogs west closer to the coast will have big implications in a place like New York City, which originally looked to be fringed by the heaviest rainfall. If the system has greater mobility to move inland, as the latest data hints is becoming more probable, then rainfall amounts could increase dramatically. The time frame to watch would be the second half of Friday into the overnight.