1. Rainfall around the southern periphery of Tropical Storm Peter may lead to areas of urban and small stream flooding from late Sunday into Tuesday across Puerto Rico, the Virgin Islands, and the Northern Leeward Islands.

There are no coastal watches or warnings in effect. Interests in the northern Leeward Islands, Virgin Islands, and Puerto Rico should monitor the progress of this system.

RAINFALL: The outer bands south of the Tropical Storm Peter could produce rainfall totals of 1 to 2 inches across portions of the Northern Leeward Islands, including the Virgin Islands, as well as Puerto Rico late Sunday into Tuesday. This rainfall may lead to areas of urban and small stream flooding.

SURF: Swells generated by Tropical Storm Peter are expected to reach the northern Leeward Islands Sunday night and Monday. These swells could cause life threatening surf and rip current conditions. Please consult products from your local weather office.

At 500 AM AST (0900 UTC), the center of Tropical Storm Peter was located near latitude 18.0 North, longitude 53.5 West. Peter is moving toward the northwest near 15 mph (24 km/h), and this general motion is expected to continue this morning. A turn back toward the west northwest is forecast to occur by this afternoon, with that motion continuing into Wednesday. On the forecast track, Peter is expected to pass well to the north of the northern Leeward Islands on Monday and Tuesday. Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Some additional strengthening is forecast during the next day or so, followed by a slow weakening trend by late Monday and on Tuesday. Tropical storm force winds extend outward up to 45 miles (75 km) from the center, mainly to the northeast and southeast of the center. The estimated minimum central pressure is 1005 mb (29.68 inches).

Deep convection has increased since the previous advisory, with the convective cloud pattern having taken on a more curved-band configuration compared to the earlier shear pattern. Satellite intensity estimates from TAFB and SAB support increasing the intensity to 35 kt. In addition, earlier ASCAT passes, which missed the center of circulation, did reveal 30-kt winds west of the center in convection-free areas. Thus, it is reasonable to assume that stronger winds are occurring within the deep convection east of the center, which further supports upgrading the system to Tropical Storm Peter with a 35-kt intensity.

The initial estimate is an uncertain 305/13 kt. Peter has made a slight jog to the north-northwest since the previous advisory, but this is likely a short-term motion owing to the center redeveloping farther to the north and east into the deep convection. However, a west-northwestward motion is expected to resume later today. Thereafter, the cyclone is forecast to maintain a west-northwestward motion through Wednesday as Peter moves around the southwestern periphery of a strong deep-layer subtropical ridge. On Thursday and Friday, Peter is forecast to turn northward into a weakness in the ridge induced by the large Post-Tropical Cyclone Odette. The new forecast track has been shifted slightly to the right or north of the previous advisory track, mainly due to the more northward initial position, and lies close to the consensus track models TVCA and HCCA.

Some strengthening is forecast during the next 24 hours or so as Peter moves over warmer sea-surface temperatures of about 29 deg C. However, proximity to very dry mid-level air and moderate deep-layer southwesterly vertical wind shear are expected to prevent any significant or rapid strengthening. By early Tuesday and beyond, slow weakening is expected to begin due to increasing wind shear. The new official NHC intensity forecast is very similar to the previous advisory, and closely follows a blend of the IVCN and HCCA intensity consensus models.

Based on the track, intensity, and wind radii forecast, no tropical storm watches or warnings are required for the northern Leeward Islands, Virgin Islands or Puerto Rico. However, interests there should monitor the progress of the system as locally heavy rain is possible on Monday and Tuesday when it is expected to pass to the north of the area.