Devastating Harvey may produce Katrina-level impacts

It's a meteorologist's worst nightmare.

A tropical storm undergoes multiple rapid intensification cycles just offshore and slams into the coast as a major hurricane.

Weak steering currents cause the intense storm to stall and linger over a heavily populated low-lying coastal area for almost a week.

The initial damage comes from wind and storm surge. Sustained winds of 125 mph lash the coast. Gusts to 140 mph tear at homes and bigger buildings. The intense eyewall rakes the shore as it crawls slowly inland.

Storm surge reaches 6 to 12 feet in some areas. A wind-driven wall of water overruns barrier islands and rushes into low-lying coastal neighborhoods. Oil refiners are submerged, causing unprecedented damage.

The eastern part of the swirling vortex remains over warm waters in the Gulf of Mexico. This continues to feed heat and moisture into the system even as it stalls over east Texas. That keeps the storm breathing, and the resulting rainfall totals of 10" to more than 40" are too much for local watersheds to handle.

What reads like scary meteorological Sci-Fi is looking more like reality in Texas. Hurricane Harvey makes landfall tonight. The storm is forecast to linger over east Texas for as long as a week.

Katrina or Sandy level impacts?

As of this writing there is strong reason to believe Harvey's impacts may rival Katrina and Superstorm Sandy in some respects. Numerical weather models continues to suggest the potential for 20" to 40" rainfall totals is there. History and hydrology shows us that level of rainfall may be catastrophic for some areas. NOAA isn't pulling any punches with Harvey. The term they use to describe likely flooding?

Catastrophic.

Here's a deeper summary of what NOAA's National Hurricane Center is thinking about Harvey's impacts.

We don't know precisely what the impacts will be. But there are already some clear signals. The impending flood situation with Harvey echoes of Katrina in 2005 and Baton Rouge last year. Houston may be next.

One big concern? The high level of oil and gas infrastructure on the Texas coast.

Here's why you may want to get gas today.

Climate change perspective on Harvey

Here's some great information and links from Climate Central on the climate change connections to hurricanes like Harvey.

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With Hurricane Harvey bearing down on the Texas coast, we wanted to remind you of some resources to help put this dangerous storm in a broader climate context. Harvey is likely to stall out, raising the specter of catastrophic inland flooding. That’s the meteorological side. But climate change is also likely playing a role in the form of heavier precipitation and higher storm surge.

In a warming world, all storms can produce more rain, as higher temperatures lead to more evaporation and more water available for precipitation. For every degree Fahrenheit increase in temperature, there is a 4 percent increase in the saturation level of the atmosphere. And as the sea level rises, coastal storm surge will move farther inland. In the last century, there have been about 7 inches of global sea level rise, mostly attributable to human-induced warming. That can be the difference between water soaking the floor and getting into its electrical outlets.

The specifics of the storm surge forecast as Harvey nears the shoreline will vary from place to place depending on the local coastal geography, but as a reference point, we have enclosed an animating image of how 6 feet of storm surge would appear at high tide in Corpus Christi. This is on the lower end of the current surge forecast from the National Hurricane Center.

Below are direct links to graphics from our archive to help with a broader discussion of the hurricane. Just click on the link and use the dropdown menu to find the information specific to your market.

• Statewide trends in heavy precipitation

• Heavy rain and sewage overflows, which serves as a reminder to stay out of floodwaters

• Trends in coastal buoy water temperatures

• Rapid increase the frequency of coastal flooding in last two decades

• Examine what 10 feet of sea level rise would look like along the Texas coast

Visit our Surging Seas interactive to view how storm surge and sea level rise can affect coastal communities across the country. Enter your city or zip code at the upper right of the interactive

You can also find sea surface temperature maps for the Gulf of Mexico at NOAA/NESDIS, which indicate Gulf of Mexico water temperatures are generally 1°-3°F degrees above normal.

Hurricane Harvey's precise meteorological impacts will unfold over the next week. The economic shock waves may reverberate for months or years.

Stay tuned.