WTPA31 PHFO 010609 TCPCP1 BULLETIN Hurricane Walaka Intermediate Advisory Number 6A NWS Central Pacific Hurricane Center Honolulu HI CP012018 800 PM HST Sun Sep 30 2018 ...WALAKA STRENGTHENS TO A HURRICANE FAR SOUTHWEST OF HAWAII... SUMMARY OF 800 PM HST...0600 UTC...INFORMATION ---------------------------------------------- LOCATION...11.7N 166.8W ABOUT 390 MI...630 KM SSE OF JOHNSTON ISLAND ABOUT 890 MI...1430 KM SW OF HONOLULU HAWAII MAXIMUM SUSTAINED WINDS...100 MPH...160 KM/H PRESENT MOVEMENT...W OR 275 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...970 MB...28.64 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: A Hurricane Warning is now in effect for Johnston Atoll. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... * Johnston Atoll A Hurricane Warning means that hurricane conditions are expected in the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm force winds, conditions that make outside preparations difficult or dangerous. Interests in the Papahanaumokuakea Marine National Monument should monitor the progress of Walaka. DISCUSSION AND OUTLOOK ---------------------- At 800 PM HST (0600 UTC), the center of Hurricane Walaka was located near latitude 11.7 North, longitude 166.8 West. Walaka is moving toward the west near 12 mph (19 km/h) and this motion is expected to slow and become northwest on Monday, then north on Tuesday. Maximum sustained winds are near 100 mph (160 km/h) with higher gusts. Rapid intensification is forecast through Tuesday. Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 90 miles (150 km). The estimated minimum central pressure is 970 mb (28.64 inches). HAZARDS AFFECTING LAND ---------------------- WIND: Tropical Storm force winds are expected across Johnston Island starting early Tuesday, with Hurricane conditions expected by Tuesday afternoon. SURF: Large surf will affect the Johnston Atoll reefs and shorelines starting Tuesday. RAINFALL: Heavy rainfall associated with Walaka may reach Johnston Atoll by Monday or Monday night. NEXT ADVISORY ------------- Next complete advisory at 1100 PM HST. $$ Forecaster Jelsema