There are no coastal watches or warnings in effect.

SURF: Large swells generated by Tropical Depression Twenty are expected to reach the Lesser Antilles and the northeastern coast of South America on Wednesday. These swells are likely to cause lifethreatening surf and rip current conditions. Please consult products from your local weather office.

At 500 PM AST (2100 UTC), the center of Tropical Depression Twenty was located near latitude 12.7 North, longitude 37.6 West. The depression is moving toward the westnorthwest near 12 mph (19 km/h). A motion toward the west or westnorthwest across the eastern and central tropical Atlantic is expected through Tuesday, followed by a slower northwestward motion Tuesday night and Wednesday. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Strengthening is forecast during the next few days. The depression is expected to become a tropical storm tonight and then will likely strengthen to a hurricane on Tuesday.

The estimated minimum central pressure is 1006 mb (29.71 inches).

The depression's center is a little closer to the deep convection compared to this morning, but the overall structure has not changed significantly. Based on this morning's ASCAT pass, and recent Dvorak estimates of T2.0 from TAFB and SAB, the initial intensity remains 30 kt. The northerly shear over the system has been analyzed to have decreased since this morning (now around 10 kt), which is probably why the center is closer to the convection. The shear is forecast to decrease further, and once the depression becomes more detached from the ITCZ/monsoon trough, it is expected to go through a significant phase of strengthening as it heads west toward higher oceanic heat content and a more unstable atmosphere. As discussed this morning, the GFS-based SHIPS guidance indicates that there is a 50-50 chance that the depression will strengthen by at least 65 kt during the next 3 days, which is 10 times higher than the climatological mean. And, all three regional hurricane models (HWRF, HMON, and COAMPS-TC), as well as the HCCA aid, show the cyclone becoming a major hurricane by the end of the forecast period. As a result, the NHC intensity forecast has been adjusted upward and now explicitly shows major hurricane strength on days 4 and 5. The motion remains west-northwestward (290/10 kt), with the depression located south of a large mid-level high centered over the central Atlantic. This feature should continue driving the system westward or west-northwestward for the next 2 days. After that time, the ridge is expected to shift northward, causing the potentially strengthening hurricane to move a little slower toward the northwest. Most of the track models are clustered close together, although the HWRF remains a southern outlier and the ECMWF model is a little slower and on the right side of the envelope. The new NHC track forecast has not moved much from the previous prediction and now lies closest to the HFIP Corrected Consensus.