* WHAT...For the High Surf Advisory, large breaking waves of 6 to 10 feet in the surf zone. For the High Rip Current Risk, dangerous rip currents. For the Coastal Flood Warning, 2 1/2 to 3 ft, locally 3 1/2 ft, of inundation above ground level expected in vulnerable areas near the waterfront and shoreline. The highest water levels are likely with the Saturday morning and possibly Sunday morning high tides. * WHERE...Southwest Suffolk and Southern Nassau Counties. * WHEN...For the High Surf Advisory, until 8 PM EDT Sunday. For the High Rip Current Risk, through Sunday evening. For the Coastal Flood Warning, during the times of high tide until 6 PM EDT Sunday. * COASTAL FLOOD IMPACTS...Widespread moderate to major flooding of vulnerable areas near the waterfront and shoreline. There is an elevated threat to low lying properties. Expect 2 1/2 to 3 ft, locally 3 1/2 ft, of inundation above ground level in low lying, vulnerable areas. Flooding could extend inland from the waterfront and shoreline into areas that typically don't experience coastal flooding. Flooding will likely be exacerbated along north facing shorelines from wave action, particularly for the barrier island from Atlantic Beach, Long Beach to Jones Beach. This will result in numerous road closures and cause widespread flooding of low lying property including parking lots, parks, lawns and homes/businesses with basements near the waterfront. Vehicles parked in vulnerable areas near the waterfront will likely become flooded. Flooding in the most vulnerable areas may not totally recede during the times of low tide. * SHOREFRONT/BEACH IMPACTS...Breaking waves of 6 to 10 ft along with elevated water levels will result in widespread dune erosion and beach flooding. Localized overwashes are possible where dune structures are compromised, resulting in some flooding of roadways and vulnerable structures behind protective dunes. Dangerous swimming and surfing conditions and localized beach erosion. Life-threatening rip currents are likely for all people entering the surf zone. Anyone visiting the beaches should stay out of the surf. Rip currents can sweep even the best swimmers away from shore into deeper water. * ADDITIONAL DETAILS....Another round of moderate to major coastal flooding is possible for the Sunday morning high tide cycle. Take the necessary actions to protect flood-prone property. If travel is required, do not drive around barricades or through water of unknown depth. Inexperienced swimmers should remain out of the water due to dangerous surf conditions. If you enter the surf zone, always have a flotation device with you and swim near a lifeguard. If caught in a rip current, relax and float, and do not swim against the current. If able, swim in a direction following the shoreline. If unable to escape, face the shore and yell or wave for help.