1. Swells generated by Sam will impact the northern Leeward Islands, the Greater Antilles, the Bahamas, Bermuda, the eastern United States and Atlantic Canada for the next couple of days. These swells could cause life-threatening surf and rip current conditions. Please consult products from your local weather office.

There are no coastal watches or warnings in effect.

Key messages for Sam can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC, and on the web at hurricanes.gov/graphics_at3.shtml?key_messages.

SURF: Swells generated by Sam will impact the northern Leeward Islands, the Greater Antilles, the Bahamas, the eastern United States and Atlantic Canada for the next couple of days. These swells could cause life threatening surf and rip current conditions. Please consult products from your local weather office.

At 500 PM AST (2100 UTC), the center of Hurricane Sam was located near latitude 35.4 North, longitude 58.2 West. Sam is moving toward the northeast near 17 mph (28 km/h). This general track with an increase in forward speed is expected by Monday for the next few days. On the forecast track, Sam will move well southeast of Newfoundland over the North Atlantic. Maximum sustained winds have decreased to near 125 mph (205 km/h) with higher gusts. Sam is a category 3 hurricane on the Saffir Simpson Hurricane Wind Scale. Further slow weakening is anticipated during the next few days, and Sam could transition into a powerful post tropical cyclone on Tuesday. Sam is a large tropical cyclone. Hurricane force winds extend outward up to 70 miles (110 km) from the center and tropical storm force winds extend outward up to 240 miles (390 km). The estimated minimum central pressure is 950 mb (28.06 inches).

The hurricane is gradually losing strength. Satellite images show that the eye has become more cloud filled, with Sam's ring of deep convection becoming less intense and two main towers in the southeast and northwest quadrants. Still, the tropical cyclone is quite a sight even on full-disk images with a large distinctive cloud pattern. The latest intensity estimates have decreased, so the initial wind speed is set to 110 kt, with higher uncertainty than average in this figure due to recent recon/satellite differences.

Sam wisely has avoided much shear during its 10-day journey across the Atlantic, and it could remain a major hurricane for another day or so. However, in 36 hours or so, the system should move north of the Gulf Stream, which would normally cause a dramatic weakening. But in this case, a favorable mid-latitude trough interaction should cause Sam to transition into a large and powerful extratropical low by 60 hours. After that, it loses its baroclinic forcing and should gradually spin down over the far North Atlantic southwest of Iceland. Guidance is in fairly solid agreement on this scenario, and the new intensity forecast is mostly just an update of the previous one, remaining close to the consensus.

The system continues moving northeastward at about 15 kt. Sam should move faster to the northeast by Monday as it encounters stronger wind flow between a deep-layer ridge to the east and a large mid- to upper-level low over Atlantic Canada. The track will weave leftward a bit at longer ranges due to the upper trough pulling the extratropical system north-northeastward at times, and eventually another trough has a similar tug by day 5. There are no significant changes to the previous forecast with guidance in close agreement.