000 WTNT33 KNHC 280842 TCPAT3 BULLETIN Hurricane Sam Advisory Number 23 NWS National Hurricane Center Miami FL AL182021 500 AM AST Tue Sep 28 2021 ...AIR FORCE HURRICANE HUNTERS FIND SAM HAS STRENGTHENED... SUMMARY OF 500 AM AST...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...17.2N 53.9W ABOUT 610 MI...980 KM E OF THE NORTHERN LEEWARD ISLANDS MAXIMUM SUSTAINED WINDS...130 MPH...215 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...953 MB...28.15 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 500 AM AST (0900 UTC), the center of Hurricane Sam was located near latitude 17.2 North, longitude 53.9 West. Sam is moving toward the northwest near 9 mph (15 km/h), and this motion is expected to continue for the next few days, with an increase in forward speed beginning on Thursday. A turn toward the north is expected by Friday. On the forecast track, Sam will pass well to the northeast of the northern Leeward Islands on Wednesday and Thursday. Data from an Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds have increased to near 130 mph (215 km/h) with higher gusts. Sam is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some fluctuations in intensity are expected during the next couple of days, but Sam is forecast to remain a major hurricane through late this week. Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km). The estimated minimum central pressure based on dropsonde data from the aircraft is 953 mb (28.15 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Sam can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC. SURF: Swells generated by Sam will impact the Lesser Antilles for the next several days. Swells are expected to reach Bermuda and the Bahamas in a couple of days, and then spread to the United States east coast late this week. These swells could cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 1100 AM AST. $$ Forecaster Reinhart