HLSLWX MDZ017-018-231100- Tropical Storm Ophelia Local Statement Advisory Number 7 National Weather Service Baltimore MD/Washington DC AL162023 1050 PM EDT Fri Sep 22 2023 This product covers Eastern West Virginia, Central and Western Maryland, Northern and Northwestern Virginia, and District of Columbia **Tropical storm conditions are expected over southern Maryland tonight through early Sunday.** NEW INFORMATION --------------- * CHANGES TO WATCHES AND WARNINGS: - None * CURRENT WATCHES AND WARNINGS: - A Tropical Storm Warning is in effect for Calvert and St. Marys * STORM INFORMATION: - About 370 miles south of Washington DC or about 370 miles south of Annapolis MD - 33.6N 76.8W - Storm Intensity 70 mph - Movement North-northwest or 330 degrees at 12 mph SITUATION OVERVIEW ------------------ Tropical Storm Ophelia will move north-northwest toward the North Carolina coast tonight before moving northward across the Mid- Atlantic Saturday through Sunday. Storm surge is expected to be the main threat to our area, especially along the western shore of the Chesapeake Bay and the tidal Potomac River where inundation of 1 to 3 feet is expected. In particular, St. Mary`s County could see significant impacts from surge where 2 to 3 feet of inundation is likely. The highest water levels will be around high tides Saturday afternoon through early Sunday morning. Widespread rainfall amounts of 2 to 4 inches are expected, with localized amounts up to 5 inches possible. This may result in isolated instances of flooding, especially for low-lying and flood prone areas. The heaviest rain is most likely to occur Saturday into Saturday night. Tropical storm force wind gusts, likely between 50 and 60 mph, are expected over southern Maryland and the nearby waters south of North Beach MD along the Chesapeake Bay, and southeast of Cobb Island MD along the tidal Potomac River. Winds are expected to begin increasing late tonight, with the strongest winds from Saturday morning through Saturday evening. Gusty winds and a saturated ground will likely cause downed trees and power outages, especially along the immediate western shoreline of the Chesapeake Bay. While the severe weather threat is low, a brief tornado or two cannot out be ruled out across southern Maryland Saturday afternoon and evening. POTENTIAL IMPACTS ----------------- * SURGE: Protect against locally hazardous surge having possible limited impacts across the western shore of the Chesapeake Bay and tidal Potomac River. Potential impacts in this area include: - Localized inundation with storm surge flooding mainly along immediate shorelines and in low-lying spots, or in areas farther inland near where higher surge waters move ashore. - Sections of near-shore roads and parking lots become overspread with surge water. Driving conditions dangerous in places where surge water covers the road. - Moderate beach erosion. Heavy surf also breaching dunes, mainly in usually vulnerable locations. - Minor to locally moderate damage to marinas, docks, boardwalks, and piers. A few small craft broken away from moorings. * FLOODING RAIN: Protect against dangerous rainfall flooding having possible significant impacts east of Interstate 95. Potential impacts include: - Rivers and tributaries may quickly become swollen with swifter currents and overspill their banks in a few places, especially in usually vulnerable spots. Small streams, creeks, canals, arroyos, and ditches overflow. - Flood waters can enter some structures or weaken foundations. Several places may experience expanded areas of rapid inundation at underpasses, low-lying spots, and poor drainage areas. Some streets and parking lots take on moving water as storm drains and retention ponds overflow. Driving conditions become hazardous. Some road and bridge closures. Protect against locally hazardous rainfall flooding having possible limited impacts across portions of southern Maryland. * WIND: Protect against hazardous wind having possible limited impacts across southern Maryland. Potential impacts in this area include: - Damage to porches, awnings, carports, sheds, and unanchored mobile homes. Unsecured lightweight objects blown about. - Many large tree limbs broken off. A few trees snapped or uprooted, but with greater numbers in places where trees are shallow rooted. Some fences and roadway signs blown over. - A few roads impassable from debris, particularly within urban or heavily wooded places. Hazardous driving conditions on bridges and other elevated roadways. - Scattered power and communications outages. * TORNADOES: Protect against a tornado event having possible limited impacts across far southern Maryland. Potential impacts include: - The occurrence of isolated tornadoes can hinder the execution of emergency plans during tropical events. - A few places may experience tornado damage, along with power and communications disruptions. - Locations could realize roofs peeled off buildings, chimneys toppled, mobile homes pushed off foundations or overturned, large tree tops and branches snapped off, shallow-rooted trees knocked over, moving vehicles blown off roads, and small boats pulled from moorings. PRECAUTIONARY/PREPAREDNESS ACTIONS ---------------------------------- * EVACUATIONS: WATCH/WARNING PHASE - Listen to local official for recommended preparedness actions, including possible evacuation. If ordered to evacuate, do so immediately. WATCH/WARNING PHASE - For those not under evacuation orders, assess the risk from wind, falling trees, and flooding at your location. If you decide to move, relocate to a safer location nearby. If you do not relocate, help keep roadways open for those under evacuation orders. * OTHER PREPAREDNESS INFORMATION: Keep your cell phone charged and in power-saving mode. If you lose power, use it sparingly and mainly for personal emergencies and check- ins. * ADDITIONAL SOURCES OF INFORMATION: - For information on appropriate preparations see ready.gov - For information on creating an emergency plan see getagameplan.org - For additional disaster preparedness information see redcross.org NEXT UPDATE ----------- The next local statement will be issued by the National Weather Service in Baltimore MD/Washington DC around 5:30 AM EDT, or sooner if conditions warrant. $$ $$