Dolly (2020)

An area of disturbed weather near the northern Bahamas on 17 June developed into a broad low off the U.S. East Coast and then became better organized east-southeast of Cape Cod. The system was classified as a subtropical depression around 1200 UTC on 22 June, became a subtropical storm early on 23 June, transitioned to a tropical storm about 6 hours later, and weakened to a remnant low by 0600 UTC on 24 June. Dolly moved generally east-northeastward to northeastward over the western Atlantic and dissipated a couple of hundred miles southeast of Nova Scotia.

Dolly did not make landfall. It remained well offshore during its entire life, so no coastal watches or warnings were issued.

The storm’s peak intensity was 40 kt (46 mph) with a minimum central pressure of 1000 mb, reached around 1200 UTC on 23 June. At peak it was a tropical storm (below hurricane strength).

Because Dolly remained over open water and north of the Gulf Stream during most of its life, there were no reported storm surge measurements or significant rainfall totals tied to the cyclone in populated coastal areas. The report did not list any surge heights or notable rain totals at cities or counties.

There were no reports of deaths or damage associated with Dolly. The storm’s impacts on land were negligible because it stayed far offshore.

Noteworthy items: Dolly began as a non-tropical/subtropical system and transitioned to a tropical storm in a marginal environment close to cold water. Its formation was poorly anticipated by forecasters—NHC’s Tropical Weather Outlook gave only low to medium chances prior to genesis—but official track and intensity forecast errors were slightly below recent averages for the small sample available.