The wave quickly organized as it neared the Windward Islands on September 20, becoming a tropical depression just two days later.

The depression strengthened into Tropical Storm Karen later that day, as it moved across the southern Windward Islands.

By 18:00 UTC that day, Karen had reached its first peak intensity with 1-minute sustained winds of 45 mph (72 km/h) and a minimum pressure of 1,003 millibars (29.6 inHg).

Karen began to degrade on September 27, when it weakened into a tropical depression, due to strong wind shear.

The wave was accompanied by a large area of convection, or showers and thunderstorms as it moved over the Cabo Verde Islands.

[3] Early the next day, an area of low pressure formed along the wave axis while it was located roughly 575 miles (925 km) east-southeast of the southern Windward Islands.

At 00:00 UTC on September 22, the wave organized into a tropical depression while located 115 miles (185 km) east of Tobago.

[1] Just three hours later, the depression organized into Tropical Storm Karen while located roughly 120 miles (190 km) southeast of St.

[5] Early on September 23, Karen's convective pattern started to become disorganized as it moved into an area of strong northeasterly vertical wind shear and dry air.

[1] Early on September 25, deep convection began to slowly increase, however, thunderstorm activity remained south of the center due to north-northeasterly wind shear.

[1] At 6:00 UTC that day, Karen re-attained tropical storm status while located roughly 90 miles (140 km) southwest of St.

[7] Karen began to slow its forward movement and shift northward around the western periphery of the subtropical ridge.

[8] At 0:00 UTC on September 25, the storm reached its initial peak intensity with one-minute sustained winds of 45 mph (72 km/h) and a minimum central pressure of 1,003 mbar (29.6 inHg), as it moved over the islands of Culebra and Vieques.

At 9:00 UTC that day, the storm reached its second peak intensity with winds of around 45 mph (72 km/h) and a minimum pressure of 1,004 mbar (29.6 inHg).

[11][12] A few hours later, the NHC noted that the storm's circulation had attached to a surface boundary that extended from the remnants of Hurricane Jerry.

[1] Just nine hours later, the system degenerated into a surface trough while located roughly 425 miles (684 km) east-southeast of Bermuda.

[31] A flash flood warning was issued for large portions of Puerto Rico by the National Weather Service (NWS).

[36] Search operations for a 48-year-old woman from Kentucky who went missing at the Virgin Islands National Park had to be briefly suspended due to the storm.

[37] Karen dropped a peak precipitation amount of 5 inches (130 mm) in Coamo, where a bridge was swept away, isolating 15 families.

[53] When Karen formed on September 22, Tropical Storm Warnings were issued for Grenada and Saint Vincent and the Grenadines.

[56] In nearby Saint Vincent and the Grenadines, a Flood Watch was issued for the country with the threat of heavy rainfall.