Tropical Cyclone Bulletin no.4

News item | 21-08-2020 | 01:58

Key Messages / Watches and warnings:

- A Tropical Storm Watch is in effect for Tropical Depression 13 (expected to become a Tropical Storm by late Thursday)
- TD 13 is expected to pass 93-98 miles (150-158 km) N of Saba/St Eustatius on Friday August 21 23:00 AST
- There is a small chance of around 10% of Tropical storm winds from late Friday till Saturday morning
- Accumulated rainfall 1-3 inch, small risk up to 5 inch
- 7-11 ft high waves are expected from late Friday into the night towards Saturday if TS conditions occur

Effect on local conditions

Winds:

There is a small chance of around 10% of Tropical Storm Conditions from late Friday till early Saturday. Winds will come from a northeasterly direction on Friday evening, ending up from a south to southeasterly direction on Saturday. Outside this period normal conditions are expected.

Seas:

Significant wave heights of 3-5 ft are expected. In case of Tropical Storm Conditions significant wave heights may increase to 5-9 ft on Friday, to 7-11 ft in easterly- to northeasterly swell in the night towards Saturday, decreasing again to 5-7 ft on Sunday.

Rainfall:

The tropical cyclone is expected to produce 1 to 3 inches of rain with isolated maximum totals of 5 inches from Friday evening through Saturday.

Local authorities and residents of Saba and St. Eustatius are advised to continue monitoring the further progress of this weather system and to take all necessary measures to safeguard life and property.

Center's latest and forecast positions:

SABA: 

Till Tue Aug 25 14:00 AST, the nearest position is estimated at: 

Fri Aug 21 23:00 AST 18.9N 62.8W Tropical Storm 150 km (93 mi) NNE of Saba 

Thu Aug 20 17:00 AST 16.7N 53.9W Tropical Depression 997 km (620 mi) E of Saba 

Fri Aug 21 02:00 AST 17.5N 57.2W Tropical Depression 640 km (398 mi) E of Saba 

Fri Aug 21 14:00 AST 18.3N 60.5W Tropical Storm 299 km (186 mi) ENE of Saba 

Sat Aug 22 02:00 AST 19.1N 63.5W Tropical Storm 166 km (103 mi) N of Saba 

Sat Aug 22 14:00 AST 20.0N 66.7W Tropical Storm 450 km (279 mi) NW of Saba 

Sun Aug 23 02:00 AST 20.9N 70.4W Severe Tropical Storm 835 km (519 mi) WNW of Saba 

ST. EUSTATIUS: 

Till Tue Aug 25 14:00 AST, the nearest position is estimated at: 

Fri Aug 21 22:00 AST 18.8N 62.5W Tropical Storm 158 km (98 mi) NNE of St. Eustatius 

Thu Aug 20 17:00 AST 16.7N 53.9W Tropical Depression 968 km (602 mi) E of St. Eustatius 

Fri Aug 21 02:00 AST 17.5N 57.2W Tropical Depression 612 km (381 mi) E of St. Eustatius 

Fri Aug 21 14:00 AST 18.3N 60.5W Tropical Storm 277 km (172 mi) ENE of St. Eustatius 

Sat Aug 22 02:00 AST 19.1N 63.5W Tropical Storm 187 km (116 mi) NNW of St. Eustatius 

Sat Aug 22 14:00 AST 20.0N 66.7W Tropical Storm 481 km (299 mi) NW of St. Eustatius 

Sun Aug 23 02:00 AST 20.9N 70.4W Severe Tropical Storm 867 km (539 mi) WNW of St. Eustatius 

Definitions:

TROPICAL STORM WATCH: A warning for tropical storm conditions, including sustained winds within the range 63-117 km/h (39-73 mph) (34-63) knots are possible in specified areas in 48 hours of less.

Next bulletin: Thursday August 20, 2020, 22:29 local time