Karen (2019)

A tropical cyclone formed from an African tropical wave and became a tropical depression about 100 nmi east of Tobago at 0000 UTC 22 September 2019, strengthening to Tropical Storm Karen six hours later. Karen moved west-northwest through the southern Windward Islands, crossed the southeastern Caribbean, turned northwest and then north as environmental conditions fluctuated, and dissipated over the central Atlantic about 300 nmi southeast of Bermuda on 27 September.

Karen moved across the Virgin Islands and Puerto Rico on 24–25 September. The storm made direct landfalls on Vieques and Culebra, Puerto Rico, late on 24 September while at tropical-storm strength; both landfalls occurred when the system’s maximum sustained winds were about 40 kt (46 mph) with central pressure near 1004 mb.

The peak estimated intensity was 40 kt (46 mph) with a minimum central pressure of about 1003 mb, corresponding to a moderate tropical storm (below hurricane strength). Karen reached this peak on 24 September south of Vieques and again briefly on 26 September well south of Bermuda.

Rainfall totals of about 2–4 inches were widespread across Puerto Rico, with isolated higher amounts near 5 inches in the island’s higher terrain; specific gauge reports included 5.00 inches at Coamo and about 4.84 inches at Rio Lajas. In the Virgin Islands and along Puerto Rico’s southern coast there were reports of elevated seas and coastal flooding; a storm-tide observation in Quart-A-Nancy (British Virgin Islands) indicated a storm surge/tide effect of about 1.38 ft, and several Puerto Rico tide and tide-plus-inundation estimates in coastal and lowland sites were around 3.0–3.5 ft.

No deaths were reported in association with Karen. Impacts included flooding and damage to roads, utility poles, and trees in Tobago (notably road damage and several uprooted trees, and boat damage in Plymouth), and in Puerto Rico numerous roads were made impassable by runoff and mudslides—especially in the municipalities of Barranquitas, Cayey, and Guayama. In Dorado two people were rescued from a flooded house, and two piers were washed out on Vieques.

Forecast and warning performance noted that genesis was predicted with only low-to-medium confidence until shortly before formation; NHC watches and warnings provided roughly 56 hours of lead time for Puerto Rico and about 38 hours of lead time for expected tropical-storm-force winds. Track and intensity forecasts were generally skillful compared with typical errors for similar storms, though some long-range forecasts had a westward bias that did not verify for Karen’s northeastern turn and eventual dissipation.