A typical autumn storm will lead to some unusual flooding over extended stretches of the eastern United States this weekend (October 30-31). Moderate to large coastal floods are expected, as a result of which some streets may be closed, possibly even the closure of factories, writes The Washington Post.
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The anticipated flooding is likely to be the worst since 2003, when Hurricane Isabelle hit the Atlantic. This may be due to a combination of coastal flow, astronomically high “royal tides” and the progressively worsening effects of sea level rise caused by anthropogenic climate change.
Coastal flood warnings extend from Virginia to New -Jersey, including the entire Delmarwa Peninsula and the shores of the Chesapeake Bay. The flood will be remarkable both for its extraordinary intensity and for its duration. The water level is expected to start dropping on Sunday morning, October 31st.
Showers and gusty winds
Storm Progress Modeling predicts rain showers and gusty winds in the southeast, and the storm itself will gradually move northward.
Wind speeds can be up to 50 miles (80 km) per hour in coastal areas and 30-40 miles (48-64 km) per hour on land inland.
Total rainfall of 1 to 1.5 inches (2.5-3.8 cm) is possible in most areas, and in some localized locations rainfall will approach 2 inches (5 cm).
The storm will gradually fade as it travels north through the Appalachians, but continued winds will pose a flood threat until Sunday morning, October 31st. The storm could even bring the highest water levels seen in Delaware Bay and break records for other floods associated with past hurricanes or winter storms. This is an important reminder that storms can be problematic even if they don't have a name.
Potentially dangerous flooding
The National Weather Service predicts that the water level in Delaware Bay near Reedy Point will reach 9.5 feet (2.8 m), corresponding to the “big” flood stage.
This will be almost three inches higher than its previous peak at 9.24 feet (2.81 m) on April 16, 2011.
It happened during a violent spring storm that hit Carolina in a hail of tornadoes, causing severe weather and coastal flooding in the Washington DC area.
“The flood could become severe enough to cause some structural damage together with flooding of the roadway near tidal streams, & # 8211; wrote to the National Meteorological Service in Mount Holly, New Jersey. & # 8211; Some places may be isolated due to flood waters. “
Meteorologists note that the biggest floods will occur on Saturday, October 30, in the evening. Especially in the Chesapeake Bay, where officials are handing out sandbags to help coastal residents protect vulnerable property and infrastructure.
The projected water level for Annapolis “will be five feet (1.5 m),” said Connor Belack, a meteorologist at the National Weather Service office in Sterling, Virginia, which serves the large Baltimore-Washington region. & # 8211; The only two higher figures were 7.16 feet (2.1 m) from Isabelle on September 19, 2003 and 6.17 feet (1.8 m) on August 23, 1933.
Belac states that in St. Mary and Calvert counties in Maryland, “dozens of roads are closed and there are also many cases where houses and basements are flooded with water. ” .
Some of the tributaries flowing into the ocean and various bays will also be prone to flooding as onshore winds raise water and impede drainage.
The Delaware River in Philadelphia may experience severe flooding for a time during high tide.
Alarming climate trend
Alexandria, Virginia, suffers from regular coastal flooding in the area where King Street meets the tidal Potomac River. This is all because of the royal tide. Royal Tide occurs when the Moon is closest to Earth in its orbit. It is often intensified in autumn and winter due to prevailing winds pushing water ashore due to the location of key large-scale weather elements.
Currently, coastal cities often experience two or three of these major events a year, and rising sea levels due to anthropogenic climate change are exacerbating the situation. For example, Charleston has regular tidal flooding, while Miami has more than 12x flooding since 1996.
According to NOAA 2018 report, since 2000 by 2015, the frequency of floods in the Mid Atlantic doubled from three days a year to an average of six.
The fact that the Mid Atlantic is preparing for severe flooding due to a small storm is another fact illustrating an irreversible trend that will only become more destructive and costly over time.