Tropical Storm Karen Develops Near Windward Islands

Tropical Storm Karen developed near the Windward Islands on Sunday morning.  At 8:00 a.m. EDT on Sunday the center of Tropical Storm Karen was located at latitude 11.9°N and longitude 60.9°W which put it about 55 miles (90 km) east-southeast of Grenada.  Karen was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1005 mb.

Tropical Storm Warnings were in effect for Trinidad and Tobago, Grenada, and for St. Vincent and the Grenadines.

A center of circulation developed in an area of thunderstorms east of the axis of a strong tropical wave near the Windward Islands on Sunday morning and the National Hurricane Center designated the system as Tropical Storm Karen.  The strongest thunderstorms were forming in bands south and west of the center of circulation.  Bands north and west of the center consisted primarily of showers and lower clouds.   Winds to tropical storm force extended out about 125 miles (200 km) on the eastern side of the tropical storm.

An upper level trough northeast of the Lesser Antilles was producing strong westerly winds which were blowing across the northern side of Tropical Storm Karen.  An upper level ridge over the Caribbean Sea was producing strong northeasterly winds which were blowing across the western part of Karen.  The upper level winds were causing moderate vertical wind shear which was inhibiting the development of thunderstorms in those parts of Tropical Storm Karen.  The center of circulation developed in a region between the stronger upper level westerly and northeasterly winds.  Most of the thunderstorms were forming in that area where the upper level winds were not as strong.

Tropical Storm Karen will move through an environment that will be only marginally favorable for intensification during the next day or two.  Karen will move over water where the Sea Surface Temperature  is near 29°C.  However, the upper level trough and upper level ridge will continue to cause moderate vertical wind shear.  If Tropical Storm Karen remains in the zone where the upper level winds are not as strong, it could strengthen.  However, if Karen moves under stronger upper level winds, it could weaken to a depression.  Tropical Storm Karen is forecast to move closer to the center of the upper level ridge in two or three days.  If that happens, then the upper level winds will be weaker and Karen could intensify.

Tropical Storm Karen will move around the western end of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Karen toward the west-northwest during the next 12 hours.  Karen will move more toward the north when reaches the end of the ridge.  On its anticipated track Tropical Storm Karen will move across the Windward Islands on Sunday.  Karen will bring gusty winds and locally heavy rain.  Flash floods are likely.  Tropical Storm Karen could approach Puerto Rico and the Virgin Islands on Tuesday.  Tropical Storm Watches are likely to be issued for those islands.

Elsewhere over the Atlantic Ocean Tropical Storm Jerry was spinning south of Bermuda.  At 5:00 a.m. EDT on Sunday the center of Tropical Storm Jerry was located at latitude 25.0°N and longitude 66.9°W which put it about 520 miles (835 km) south-southwest of Bermuda.  Jerry was moving toward the north-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 1002 mb.