Climate Matters

Houston Flooding

Hello Climate Matters Mets,

Below is some information about the phenomenal flooding taking place in Houston today, along with some graphics to help you tell the climate story. As always, let us know if you have any questions.

Sean

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Phenomenal flooding started Sunday night and continues on Monday in and around Houston thanks to torrential rains. In just over 5 hours, at 5:20 a.m. Central time, Houston Intercontinental Airport had already received 8.85 inches of rain, breaking its previous rainfall record for the date (8.16 inches in 1976).

Numerous roads are closed as rain and thunderstorms continue this morning. Houston METRO has suspended all transit services including local bus, Park and Ride and light-rail. Many schools have closed, including the University of Houston. According to the National Weather Service office in Houston, 70 subdivisions in the metro area were flooded by 7 a.m. Central time.

To help residents affected by flooding, the Red Cross has opened shelters around the metro area. Emergency responders have conducted more than 100 water rescues in the City of Houston, Mayor Sylvester Turner said in a Monday morning briefing. Residents have been advised to avoid travel unless they are fleeing floodwaters.

While the airport set a rainfall record, other areas have also been deluged as rains sometimes fell at rates up to several inches per hour. Rain gauges and radar estimates indicate up to 16 inches of rain have fallen in parts of the metro area.

Below are some of the more notable 12-hour rain totals from the Harris County Flood Warning System as of 8 a.m. Central time:

  • 16.28 inches – Little Mound Creek
  • 15.60 inches – Cypress Creek
  • 14.72 inches – Langham Creek
  • 13.96 inches – Bear Creek
  • 11.72 inches – Little Cypress Creek
  • 10.64 inches – Spring Creek
  • 10.56 inches – Greens Bayou

The heavy rain has inundated roads and caused creeks to rise rapidly. Cypress Creek rose 21 feet in only five hours, White Oak Bayou rose 28 feet in 10 hours. Water has started to overtop Interstate 10 at White Oak Bayou near downtown Houston, with cars floating on the Interstate.

A slow moving front sitting over eastern Texas, combined with a deep flow of moisture from the Gulf of Mexico caused rain and thunderstorms to pop up overnight on Sunday. More rain is expected through Monday night and into Tuesday before the area begins drying out on Wednesday.

The magnitude of this flood event could be similar to Tropical Storm Allison, which inundated Houston and other parts of the Southeast in June 2001. At the time, Allison was the costliest tropical storm in U.S. history, causing $9 billion in damage. Two-thirds of Harris County received over 10 inches of rain from that storm with up to 20 inches falling in northeast Houston.

While no attribution of this event is immediately available, this deluge is certainly in line with a trend of increased downpours due to climate change not just in Houston but across the U.S.

Enclosed is a graphic illustrating that the nationwide number of days with 3 inches or more of rain has increased since 1950. Additional graphics to help tell the story in a climate context are below.

Additional Information

Heavy downpours on the rise embeddable interactive for your blog or station site >>

When It Rains, It Pours (video)
Heavy Precip Trends in the U.S.
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