Subtropical Depression Four has strengthened into Tropical Storm Dolly at 1:00 PM AST. It is the 3rd earliest 4th Atlantic named storm formation on record (since 1851). Danielle is earliest on June 20th, 2016. Debby is 2nd earliest on June 23rd, 2020 at 12 UTC. Dolly in 2020 formed on June 23 at 1615 UTC.
Dolly comes 51 days ahead of the date when the average named tropical cyclone forms, with only 2016 and 2012 having 4 named storms before July.
At 1:00 PM AST, the center of Tropical Storm Dolly was located near latitude 39.4 North, longitude 61.7 West.
Dolly is moving toward the east-northeast near 13 MPH (20 KM/H). A turn toward the northeast with an increase in forward speed is expected tonight and on Wednesday.
Satellite-derived wind data indicate that maximum sustained winds have increased to near 45 MPH (75 KM/H) with higher gusts. Weakening is forecast during the next day or two as Dolly moves over colder waters, and the system is expected to become post-tropical on Wednesday. The low should then dissipate by early Thursday.
Tropical-storm-force winds extend outward up to 70 miles (110 KM) to the south of the center. The estimated minimum central pressure is 1002 millibars.
Watches & Warnings
There are no watches or warnings in effect, as this system moves into the North Atlantic Ocean, away from land masses.
Hazards Affecting Land
There are no hazards affecting land at this time.
This system is of no threat to the Windward Islands, including Trinidad and Tobago.
Tropical Storm Dolly Forecast Discussion
A 1348 UTC ASCAT-A scatterometer pass, arriving just after the previous advisory was issued, indicates that the cyclone is producing winds of 35-40 kt in its southern semicircle. In addition, the radius of maximum winds has contracted to about 40 n mi. This, along with the current convective pattern, suggests that the system has made a transition from a subtropical to a tropical cyclone, and it has been designated as Tropical Storm Dolly.
This Special Advisory package is being issued to update the intensity and wind radii forecasts, increasing Dolly’s maximum winds at each forecast time by 5 kt during the next 24 hours. The forecast track and status changes are the same as in the previous advisory.
Forecast Discussion by Forecaster Berg from the NHC.