Flash Floods

Flash Floods

What are flash floods?(by Michelle Cohn)

According to the National Climate Data Center, flash floods are short-term events which occur within 6 hours of an event such as heavy rain, a dam break, levee failure, snow melting and ice jams. Most often, a flash flood can occur within 2 hours of the start of high intensity rainfall.

A flash flood is characterized by a quickly rising stream with depths of water that can reach well above the banks of the creek. 

Flash floods can cause a lot of damage to the areas they occur in and may even cause death. Damage and most fatalities are likely to occur in areas that are right next to a stream or arroyo. 

More about Flash Floods (by Ms. Bernstein) 

According to the National Oceanic and Atmospheric Administration, Flash floods occur rapidly and are very dangerous. Flash floods can be produced when slow moving or multiple thunderstorms occur over the same area. When storms move faster, flash flooding is less likely since the rain is distributed over a broader area.

This is a great video from Brain Pop about Natural Disasters, which includes Flash Floods- https://www.brainpop.com/science/earthsystem/naturaldisasters/

Flash Floods in Motion! (by Morin Yosef)

Flash Flood Charts and Questions (by Morin Yosef)

Here are two charts with data that was collected from the National Climatic Data Center Website  
These charts show information about Flash floods that occurred in the last 20 years in Staten Island (Richmond County) New York. Which month had the most flash floods? 

Which year has the most floods?
Which year had the least flash floods? If there is more than one year, please list all that show the least amount of flash floods.

Can flash floods happen where you live? (by Jane Belaya)

According to the National Climatic Data Center, in the last twenty years, Richmond County has only had twenty nine flash flood reports in only two areas of the county. The most recent event happened on June 13th, 2014 and lasted a little over seventeen minutes.

The flash flood occurred after an approaching cold front triggered a line of thunderstorms that produced heavy rain and resulted in flash flooding in portions all over New York City. In Richmond county, the ramp from Lily Pond Ave. to the lower level of the Brooklyn bound Verrazano Bridge was closed due to flooding. 

Since the most recent flash flood event occurred in June and over the last twenty years, the most flash floods have happened during June and July; it can be predicted that during the warmer months, a flash flood could be occur after heavy periods of rain.

How much damage can flash floods cause? (by Judy Allen)

According to the environment national geograpic.com in the United States flood do about 6 million dollars worth of damage and kill about 140 people each year. A 2007 report by the Organization for Economic Cooperation and development found that coastal flooding alone does some $3 trillion in damage worldwide