151 WHUS42 KCHS 182138 CFWCHS Coastal Hazard Message National Weather Service Charleston SC 538 PM EDT Mon May 18 2026 SCZ149-150-190400- /O.NEW.KCHS.CF.Y.0012.260519T0100Z-260519T0400Z/ Coastal Colleton-Charleston- 538 PM EDT Mon May 18 2026 ...COASTAL FLOOD ADVISORY IN EFFECT FROM 9 PM THIS EVENING TO MIDNIGHT EDT TONIGHT... * WHAT...Up to one half foot of inundation above ground level expected along shorelines and tidal waterways (7.0 to 7.2 feet Mean Lower Low Water at Charleston). * WHERE...Coastal Colleton and Charleston Counties. * WHEN...From 9 PM this evening to midnight EDT tonight. * IMPACTS...This could result in some roads becoming impassable. * ADDITIONAL DETAILS...High tide will occur around 10:19 PM today at Charleston. Saltwater inundation will be possible 1 to 2 hours before and after high tide. PRECAUTIONARY/PREPAREDNESS ACTIONS... If travel is required, allow extra time as some roads may be closed. Do not drive around barricades or through water of unknown depth. Take the necessary actions to protect flood-prone property. Visit water.weather.gov for additional water level and flood impact information. && Time of high total tides are approximate to the nearest hour. Charleston Harbor SC MLLW Categories - Minor 7.0 ft, Moderate 7.5 ft, Major 8.0 ft MHHW Categories - Minor 1.2 ft, Moderate 1.7 ft, Major 2.2 ft Total Total Departure Day/Time Tide Tide from Norm Waves Flood ft MLLW ft MHHW ft ft Impact -------- --------- --------- --------- ------- -------- 18/10 PM 7.1 1.3 0.5 N/A Minor 19/11 AM 5.3 -0.5 0.3 N/A None 19/11 PM 6.9 1.1 0.5 N/A None 20/12 PM 5.2 -0.6 0.3 N/A None 21/12 AM 6.5 0.7 0.4 N/A None 21/01 PM 5.3 -0.5 0.4 N/A None && $$