HLSLWX DCZ001-MDZ003>006-011-013-014-016>018-503>508-VAZ025>031-036>040-050>057-501-502-505>508-WVZ050>053-055-032200- Tropical Storm Isaias Local Statement Advisory Number 25 National Weather Service Baltimore MD/Washington DC AL092020 535 AM EDT Mon Aug 3 2020 This product covers Eastern West Virginia, Central and Western Maryland, Northern and Northwestern Virginia, and District of Columbia **Tropical Storm Warnings are now in effect for portions of southern Maryland. Tropical Storm Watches remain in effect for the Baltimore and Washington metro areas.** NEW INFORMATION --------------- * CHANGES TO WATCHES AND WARNINGS: - The Tropical Storm Watch has been upgraded to a Tropical Storm Warning for Calvert and St. Marys * CURRENT WATCHES AND WARNINGS: - A Tropical Storm Warning is in effect for Calvert and St. Marys - A Tropical Storm Watch is in effect for Anne Arundel, Arlington/Falls Church/Alexandria, Charles, District of Columbia, Fairfax, King George, Prince Georges, Prince William/Manassas/Manassas Park, Southeast Harford, Southern Baltimore, and Stafford * STORM INFORMATION: - About 660 miles south-southwest of Washington DC or about 690 miles south-southwest of Baltimore MD - 29.7N 79.9W - Storm Intensity 70 mph - Movement North or 355 degrees at 9 mph SITUATION OVERVIEW ------------------ Significant flash flooding of small streams and creeks is likely tonight 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 tonight 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: Protect against life-threatening rainfall flooding having possible extensive impacts across much of the area. 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. Protect against dangerous rainfall flooding having possible limited to significant impacts across much of the area. * WIND: Protect against 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. Also, protect against hazardous wind having possible limited impacts across the Washington and Baltimore metro area. * SURGE: Protect against locally hazardous surge having possible limited impacts across southern Maryland. 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. * TORNADOES: Protect against a tornado event having possible limited impacts across 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. Elsewhere across Eastern West Virginia, Central and Western Maryland, Northern and Northwestern Virginia, and District of Columbia, little to no impact is anticipated. 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 complete all preparations to protect life and property in accordance with your emergency plan. Ensure you are in a safe location before the onset of strong winds or possible flooding. If you are relocating to safe shelter, leave as early as possible. Allow extra time to reach your destination. Many roads and bridges will be closed once strong winds arrive. Check the latest weather forecast before departing and drive with caution. If heading to a community shelter, become familiar with the shelter rules before arrival, especially if you have special needs or have pets. Take essential items with you from your Emergency Supplies Kit. Failure to adequately shelter may result in serious injury or loss of life. Always heed the advice of local officials and comply with any orders that are issued. Remember, during the storm 9 1 1 Emergency Services may not be able to immediately respond if conditions are unsafe. This should be a big factor in your decision making. Keep cell phones well charged. Cell phone chargers for automobiles can be helpful, but be aware of your risk for deadly carbon monoxide poisoning if your car is left idling in a garage or other poorly ventilated area. It is important to remain calm, informed, and focused during an emergency. Be patient and helpful with those you encounter. If you are a visitor, be sure to know the name of the city or town in which you are staying and the name of the county or parish in which it resides. Listen for these locations in local news updates. Pay attention for instructions from local authorities. Storm surge is the leading killer associated with tropical storms and hurricanes! Make sure you are in a safe area away from the surge zone. Even if you are not in a surge-prone area, you could find yourself cutoff by flood waters during and after the storm. Heed evacuation orders issued by the local authorities. Rapidly rising flood waters are deadly. If you are in a flood-prone area, consider moving to higher ground. Never drive through a flooded roadway. Remember, turn around don`t drown! If a Tornado Warning is issued for your area, be ready to shelter quickly, preferably away from windows and in an interior room not prone to flooding. If driving, scan the roadside for quick shelter options. 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, consider moving to a safer shelter before the onset of strong winds or flooding. Closely monitor weather.gov, NOAA Weather radio or local news outlets for official storm information. Be ready to adapt to possible changes to the forecast. Ensure you have multiple ways to receive weather warnings. * 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 1130 AM, or sooner if conditions warrant. $$ $$