HLSLWX DCZ001-MDZ003>006-011-013-014-016>018-503>508-VAZ025>031-036>040-050>057-501-502-505>508-WVZ050>053-055-031130- Tropical Storm Isaias Local Statement Advisory Number 24 National Weather Service Baltimore MD/Washington DC AL092020 1121 PM EDT Sun Aug 2 2020 This product covers Eastern West Virginia, Central and Western Maryland, Northern and Northwestern Virginia, and District of Columbia **Tropical Storm Watches remain in effect for the Baltimore and Washington metro areas and southern Maryland** NEW INFORMATION --------------- * CHANGES TO WATCHES AND WARNINGS: - None * CURRENT WATCHES AND WARNINGS: - A Tropical Storm Watch is in effect for Anne Arundel, Arlington/Falls Church/Alexandria, Calvert, Charles, District of Columbia, Fairfax, King George, Prince Georges, Prince William/Manassas/Manassas Park, Southeast Harford, Southern Baltimore, St. Marys, and Stafford * STORM INFORMATION: - About 740 miles south-southwest of Washington DC or about 770 miles south-southwest of Baltimore MD - 28.5N 79.8W - Storm Intensity 70 mph - Movement North-northwest or 345 degrees at 9 mph SITUATION OVERVIEW ------------------ Significant flash flooding of small streams and creeks is likely Monday night into Tuesday evening as rainfall associated with Tropical Storm Isaias spreads northward. Widespread rainfall totals of 3 to 6 inches are expected with locally higher amounts possible. The highest amounts are expected east of the Blue Ridge Mountains particularly over the I-95 corridor late Monday night through Tuesday. Moderate coastal flooding is also possible at times of high tide Tuesday as Isaias makes its closest approach to the area. Minor wind damage and scattered power outages are also possible especially across southern Maryland. POTENTIAL IMPACTS ----------------- * FLOODING RAIN: Prepare for life-threatening rainfall flooding having possible extensive impacts across all areas along and east of the Interstate 81 corridor. Potential impacts include: - Major rainfall flooding may prompt many evacuations and rescues. - Rivers and tributaries may rapidly overflow their banks in multiple places. Small streams, creeks, canals, arroyos, and ditches may become dangerous rivers. In mountain areas, destructive runoff may run quickly down valleys while increasing susceptibility to rockslides and mudslides. Flood control systems and barriers may become stressed. - Flood waters can enter many structures within multiple communities, some structures becoming uninhabitable or washed away. Many places where flood waters may cover escape routes. Streets and parking lots become rivers of moving water with underpasses submerged. Driving conditions become dangerous. Many road and bridge closures with some weakened or washed out. Prepare for dangerous rainfall flooding having significant impacts across reas along and east of Interstate 81 corridor. The threat is particularly high along and east of the Interstate 95 corridor. * SURGE: Prepare for locally hazardous surge having possible limited impacts along the tidal shores of the Chesapeake Bay and 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. Strong rip currents. - Minor to locally moderate damage to marinas, docks, boardwalks, and piers. A few small craft broken away from moorings. Elsewhere across Eastern West Virginia, Central and Western Maryland, Northern and Northwestern Virginia, and District of Columbia, little to no impact is anticipated. * WIND: Prepare for dangerous wind having possible significant impacts across southern Maryland. Potential impacts in this area include: - Some damage to roofing and siding materials, along with damage to porches, awnings, carports, and sheds. A few buildings experiencing window, door, and garage door failures. Mobile homes damaged, especially if unanchored. Unsecured lightweight objects become dangerous projectiles. - Several large trees snapped or uprooted, but with greater numbers in places where trees are shallow rooted. Several fences and roadway signs blown over. - Some roads impassable from large debris, and more within urban or heavily wooded places. A few bridges, causeways, and access routes impassable. - Scattered power and communications outages, but more prevalent in areas with above ground lines. * TORNADOES: The risk of isolated tornadoes exists near and to the southeast of the track of Isaias. 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. * OTHER PREPAREDNESS INFORMATION: Now is the time to check your emergency plan and emergency supplies kit and take necessary actions to protect your family and secure your home or business. When making safety and preparedness decisions, do not focus on the exact forecast track since hazards such as flooding rain, damaging wind gusts, storm surge, and tornadoes extend well away from the center of the storm. If in a place that is vulnerable to high wind, such as near large trees, a manufactured home, upper floors of a high-rise building, or on a boat, plan to move to safe shelter. If you live in a place particularly vulnerable to flooding, such as near the ocean or a large inland lake, in a low-lying or poor drainage area, in a valley, or near an already swollen river, plan to move to safe shelter on higher ground. Always heed the advice of local officials and comply with orders that are issued. Do not needlessly jeopardize your life or the lives of others. When securing your property, outside preparations should be concluded as soon as possible before conditions deteriorate. The onset of strong gusty winds or flooding can cause certain preparedness activities to become unsafe. Be sure to let friends and family members know of your intentions for weathering the storm and your whereabouts. Have someone located away from the threatened area serve as your point of contact. Share vital contact information with others. Keep cell phones handy and charged. Check on those who may not be fully aware of the situation or who are unable to make personal preparations. If you are a visitor, know the name of the county or parish in which you are located and where it is relative to current watches and warnings. If staying at a hotel, ask the management staff about their onsite disaster plan. Listen for evacuation orders, especially pertaining to area visitors. Closely monitor weather.gov, NOAA Weather Radio and local news outlets for official storm information. Listen for possible changes to the forecast. There is a threat from tornadoes with this storm. Have multiple ways to receive Tornado Warnings. Be ready to shelter quickly. * 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 AM EDT, or sooner if conditions warrant. $$ $$