HLSLWX DCZ001-MDZ003>006-011-013-014-016>018-503>508-VAZ027>031-036>040-050>057-501-502-505>508-WVZ051>053-040830- Hurricane Isaias Local Statement Intermediate Advisory Number 27A National Weather Service Baltimore MD/Washington DC AL092020 828 PM EDT Mon Aug 3 2020 This product covers Eastern West Virginia, Central and Western Maryland, Northern and Northwestern Virginia, and District of Columbia **STRONG WINDS AND FLOODING RAINFALL LIKELY TONIGHT AND TUESDAY** NEW INFORMATION --------------- * CHANGES TO WATCHES AND WARNINGS: - None * CURRENT WATCHES AND WARNINGS: - A Tropical Storm Warning is in effect for Anne Arundel, Arlington/Falls Church/Alexandria, Calvert, Carroll, Central and Southeast Howard, Central and Southeast Montgomery, Charles, District of Columbia, Fairfax, King George, Northern Baltimore, Northwest Harford, Northwest Howard, Northwest Montgomery, Prince Georges, Prince William/Manassas/Manassas Park, Southeast Harford, Southern Baltimore, Spotsylvania, St. Marys, and Stafford * STORM INFORMATION: - About 440 miles south-southwest of Washington DC or about 470 miles south-southwest of Baltimore MD - 32.8N 79.0W - Storm Intensity 75 mph - Movement North-northeast or 15 degrees at 16 mph SITUATION OVERVIEW ------------------ Hurricane Isaias will approach from the Carolinas tonight and move across the Chesapeake Bay region Tuesday morning. The center of the storm will rapidly exit to the northeast Tuesday afternoon. Significant flash flooding of small streams and creeks is likely tonight into Tuesday evening as rainfall associated with 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, and particularly over the I-95 corridor late tonight through Tuesday. Tropical storm force winds are expected along and east of the I-95 Corridor and north central Maryland. Tree damage and power outages are possible in this area. The strongest winds are expected across southern Maryland, where tree damage and power outages are more likely. Moderate coastal flooding is also likely along the western shores of the Chesapeake Bay and at Washington DC Southwest Waterfront on Tuesday. Minor coastal flooding is likely along other tidal waters. POTENTIAL IMPACTS ----------------- * FLOODING RAIN: Protect against life-threatening rainfall flooding having possible extensive impacts near and east of I-95 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 possible limited to significant impacts across other locations near and east of the Blue Ridge Mountains. * 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 elsewhere near and east of the Interstate 95 corridor. * SURGE: Protect against locally hazardous surge having possible limited impacts across along the Tidal Potomac River and along the western shore of the Chesapeake Bay. 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. * 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 ---------------------------------- 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. 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. 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. 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 PM EDT, or sooner if conditions warrant. $$ $$