
Harvey To Become “Major Hurricane”— Major Flooding Disaster for Texas
“..Harvey quickly strengthening and forecast to become a major hurricane when it approaches the middle Texas coast… Life threatening storm surge and freshwater flooding is expected…” — Forecaster, Berg. National Hurricane Center, 10 AM Public Advisory.

A major disaster is likely to occur over parts of southern Texas and southeast Louisiana this weekend. As of the 10 AM Advisory, the National Hurricane Center (NHC) indicated that Hurricane Harvey is forecast to become a major hurricane as it approaches Texas coast line.
The rapidly intensifying storm is forecast make landfall on Friday, then slowly drift northeast along the Texas coast through Tuesday. It is expected to bring hurricane force winds, storm surge, and up to 2.5 feet of rain to parts of middle/southeast Texas and portions of southwestern Louisiana. Low lying coastal cities like Port O’Connor, Texas are likely to experience catastrophic flooding.
Latest Update:
As of 10 am, the National Hurricane Center (NHC) says that Tropical Storm Harvey is positioned about 365 miles SE of Corpus Christi, Texas. Maximum sustained winds are 65 mph with higher wind gusts. The storm is moving NNW about 10 mph.
Warnings.
“A strong surge warning means there is a danger of life-threatening inundation… from rising water moving inland from the coast line…” 10 AM FCT Advisory — National Hurricane Center
Hurricane Warnings have been posted for south of Ports Mansfield to Matagorda,Texas in anticipation of sustained, Category 3, winds ranging from 111–129 mph. The NHC has also posted Storm Surge Warnings from Port Mansfield to San Luis Pass, TX.
Forecast — Landfall on Friday

Strengthening is forecast through Friday due to favorable atmospheric conditions in the Gulf of Mexico. NHC says that Harvey could become a major hurricane it nears Texas coastline on Friday. Forecasts tracks indicate that the storm will move on shore near Corpus Christi, Texas sometime Friday as a major (Cat 3+) hurricane. Models seem to agree that a lack of steering flow aloft will allow the storm to meander along Texas coastline for about 3–4 days before being pushed off to the north and the east on Wednesday.

During the period Friday through Tuesday, Quantitative Precipitation Forecasts (QPF) feature potentially record breaking amounts of heavy rain parts of the Texas and Louisiana coastline. WPC’s QPF guidance features at least 4–6" of rain per day over portions of the Texas coast regions. Through Tuesday, as much as 15.0–20.0" inches of rain could fall over middle and southeast Texas. Locally heavy amounts to 30.0" could fall over cities like Corpus Christi, Houston, Galveston, and Beaumont, Texas.
Although not initially in the path of the storm, residents in southeastern Louisiana should monitor Harvey’s track during the course of the event. Forecasters are warning that Harvey’s extremely heavy rainfall could drift east as the storm begins to get picked up by increasing wind flow aloft Mon/Tue. There is the potential for widespread rainfall amounts on the order of 6.0" to 10.0"+ for locations near Lake Charles, LA.
Here’s the latest GFS solution.

Impacts — Extensive Wind Damage, Tornadoes, Surge, and Major Flooding Likely
Extensive Wind Damage. As previously mentioned, the NHC expects Harvey to become a major hurricane by the time it reaches Texas on Friday. Major hurricanes are classified as category 3 or higher storms. Making landfall as a category 3 hurricane, Harvey could pack sustained winds of 111–129 mph with higher gusts. For those areas under a hurricane warning, these winds will likely result in moderate to severe structural damage along with widespread tree damage and power loss.
Tornadoes. Tropical systems are known for producing a large number of weak tornadoes. Favorable wind-shear profiles on the storms’ right upper quadrant often result in weak, fast moving tornadoes lasting under 5 minutes in duration.Although weak, these tornadoes can cause significant structural damage and snap trees/power-lines.
As Harvey is expected to maintain a strong presence in middle and southeast Texas/southwest Louisiana for several days, weak tornadoes may become a more prevalent issue. Those beyond the zone of hurricane force winds should be especially vigilant as these short lived tornadoes can form without warning and are often rain wrapped.
Storm Surge. There is serious cause to be concerned about storm surge and the potential for record setting rainfall. Texas coastal plains are extremely flat, allowing for extensive inundation of storm surge with minor water level increases. As Harvey is now anticipated to become a major hurricane, widespread, extensive coastal-flooding is expected for the warned areas.
Major Inland Flooding. Harvey’s torrential rainfall will likely lead to devastating inland flooding. Extremely low grades along the coast plains will struggle to drain the high volume of rainfall that is expected Friday. Major to catastrophic flooding is possible as water ways quickly back up in to smaller creeks, streams, and urban areas.