The National Oceanic and Atmospheric Administration predicts 30 days of flooding per year in U.S. coastal cities by 2050 in a new study Thursday. 

The study, published in the American Geophysical Union's Earth's Future Journal, found that flooding in U.S. coastal cities is already five to 10 times more likely, CBS News reported. 

The study used 50 years of NOAA's tidal gauges data to find that flooding along coastal cities could reach up to two feet by 2050. Researchers estimate 30 days or more of flooding for these areas.

Researchers said Baltimore, New York City, Norfolk, Va., Philadelphia, Washington, D.C. and Wilmington, N.C. would experience the worst of the flooding along the east coast.

The study included Galveston Bay and Port Isabel, Texas as well as San Diego and San Francisco as other potentially hard-hit cities.

Miami could not be included in the study because its NOAA tide station was destroyed in 1992 by Hurricane Andrew, according to CBS.

Scientists expect tidal flooding to get worse in Miami over the next 15 years. A study in the journal Climatic Change predicts blackouts across 30 cities from Texas to Maine due to hurricanes.

Sea levels rise because warming global temperatures melt ice sheets and cause thermal expansion of the oceans, The Huffington Post reported.

Researchers predict a sea level rise of 1.5 feet by 2100, but this projection is a best case scenario.