Ellicott City rainfall is predictably unpredictable

ANNAPOLIS, Maryland Ellicott City, Maryland, sustained two cataclysmic flash floods in the span of 22 months, the first in July 2016, the other in May.

“Although the two events are considered abnormal weather phenomena, the fact remains that precipitation levels overall have been increasing in the mid-Atlantic region for the past 10 years,” said Jason Elliott, senior service hydrologist from the National Weather Service in an interview with Capital News Service.

Monday marked the rainiest November in Washington, D.C., breaking a 141-year-old record, according to the National Weather Service. As of Tuesday, the city was sitting at the No. 3 spot in terms of the rainiest year on record with 57.38 inches. Baltimore broke its November record on Saturday with a total of 7.72 inches of precipitation.

From May through July, much of the East Coast, especially the Mid-Atlantic, experienced rain up to 300 percent of normal, according to data from the National Oceanic and Atmospheric Administration (NOAA).


In May, areas from Pennsylvania down to Florida saw rains 100 to 200 percent of normal. By June and July, the heaviest rains were focused over the Mid-Atlantic, according to NOAA data. During this summer period, monthly rain in Washington, D.C., through central Pennsylvania was well over 200 percent of normal.

From June 1 through Aug. 13, over 23 inches of rain was collected at Baltimore/Washington International Airport over 250 percent of normal.

The rains in Maryland have been so heavy that the period from May through July was the wettest for those months in state history — recorded over the past 124 years — with July becoming the second-wettest July on record, Elliott said.

“We can forecast quite accurately when the conditions for heavy rainfall exist,” Elliott told Capital News Service in an interview in October. “However, it is still very difficult to forecast precisely where a flash flood will occur.”

Nevertheless, the National Weather Service strongly advises that the public take all flash flood warnings, advisories and watches very seriously.


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