Tropical Storm Karen forms, eyes Puerto Rico

Tropical Storm Karen formed Sunday morning at 5 a.m. just east of the Windward Islands. It’s likely to affect Puerto Rico by midweek as a tropical storm, although it’s not out of the question that it could intensify into a hurricane shortly before either making landfall there or passing just off the coast.

Puerto Rico is extremely vulnerable to a tropical storm or hurricane, given the extensive and ongoing recovery effort in the wake of Hurricane Maria, which hit in 2017. The power grid remains fragile, with power outages occurring even without the presence of significant storms, and many people still sleeping in temporary structures vulnerable to wind damage.

Tropical storm warnings are in effect for Trinidad and Tobago as well as Grenada. As of Sunday morning, tropical storm watches included St. Vincent and the Grenadines. As of 8 a.m. Sunday, the center of circulation was just north of Tobago, and Karen was moving west-northwest at 9 mph.

Maximum sustained winds were at 40 mph, but covered an exceptionally broad area — spreading up to 125 miles away from the center. The storm is in a moderate to highly sheared environment, meaning the surrounding winds are blowing with different speed and/or direction with height, and this will limit the ability for Karen to consolidate its thunderstorms and intensify during the next one to two days, according to the National Hurricane Center.

While minor fluctuations in strength are possible for now, Karen is expected to begin intensifying once conditions become more favorable, with lower levels of wind shear, by late Monday.

The latest forecasts call for Karen to meander north-northwestward through the eastern Caribbean and then turn northwards as it approaches Puerto Rico on Tuesday. It’s likely to make its closest pass just east of, or over Puerto Rico, late Tuesday into Wednesday.