1. Regardless of Karen's status and intensity, the system is expected to bring heavy rainfall, flash floods and mudslides to Puerto Rico and the U.S. and British Virgin Islands on Tuesday, where a tropical storm warning is in effect. The rainfall and potential flooding will likely continue on Wednesday even as the center of Karen moves away from Puerto Rico and the Virgin Islands.

WHAT'S NEW:

None

SUMMARY OF ALERTS:

A Tropical Storm Warning is in effect for...
- U.S. Virgin Islands
- Puerto Rico, including Vieques and Culebra
- British Virgin Islands

A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. Interests elsewhere in the Lesser Antilles should monitor the progress of Karen. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service.

Rainfall: Karen is expected to produce the following rainfall accumulations through Wednesday:

Puerto Rico and the Virgin Islands...2 to 4 inches, isolated 8 inches.

Leeward Islands...1 to 3 inches, isolated 5 inches.

These rains may cause flash flooding and mudslides, especially in mountainous areas.

WIND: [TOP] Tropical storm force winds, especially in gusts, are expected in the warning area by early Tuesday. Winds could be higher on the windward sides of hills and mountains.

At 1100 PM AST (0300 UTC), the center of Tropical Depression Karen was located near latitude 16.1 North, longitude 65.8 West. The depression is moving toward the north-northwest near 9 mph (15 km/h). A turn toward the north is expected by early Tuesday, and a northward to north-northeastward motion should continue through Wednesday night. On the forecast track, the center of Karen will pass near or over Puerto Rico and the Virgin Islands on Tuesday, and then move over the western Atlantic Tuesday night and Wednesday.

Maximum sustained winds remain near 35 mph (55 km/h) with higher gusts. Slow strengthening is forecast during the next few days.

The minimum central pressure based on data from the Air Force Hurricane Hunters and surface observations is 1008 mb (29.77 inches).

Deep convection associated with Karen has increased during the past few hours, but the thunderstorm activity remains confined to the south of the center due to north-northeasterly shear. The Air Force Hurricane Hunters have been investigating the depression this evening, and a combination of the flight-level and SFMR data indicate that winds are just below tropical-storm-force. The aircraft measured a minimum pressure of about 1008 mb.

Karen is currently situated near the western periphery of a subtropical ridge, and it is forecast to turn northward on Tuesday as it passes Puerto Rico and the Virgin Islands. After that time, a northward to north-northeastward motion seems likely as the cyclone moves into a weakness left behind by Tropical Storm Jerry. However, the models indicate that the trough will not capture Karen, and instead the cyclone could come to a stop or drift westward by the weekend as a ridge builds to the north of the system. Although the models agree on the overall scenario, the details are quite uncertain and there remains a large spread in the guidance at days 4 and 5. The new NHC track forecast is adjusted a little to the right of the previous one to be in better agreement with the latest consensus models.

The environment is still quite hostile around Karen with north-northeasterly shear of about 20 kt currently impacting the cyclone. However, the upper-level wind pattern is expected to become more favorable during the next few days, and that could give it an opportunity to strengthen. The NHC intensity forecast shows a slow increase in winds through the forecast period. This forecast is similar to the previous one, and lies roughly between the aggressive SHIPS/LGEM models and the HWRF/HMON models which show little change in intensity during the next several days.