Harvey went from not even a tropical storm to a major Category 4 hurricane in 56 hours, an incredibly fast intensification for a storm.
The storm is over very warm waters (85-88 degrees) in an environment with low wind shear. The storm strengthened into a major hurricane — a Category 4.
The National Hurricane Center said the eye of the Category 4 hurricane made landfall about 10 p.m. Friday about 30 miles east-northeast of Corpus Christi between Port Aransas and Port O'Connor, Texas, bringing with it 130 mph sustained winds and flooding rains.
Like any major hurricane, the concerns with Harvey will be flooding, storm surge and hurricane-force winds. This storm, however, will mostly be known for the flooding. Rain fall totals are projected to be as high as 30 inches, and the possibility of 40-inch rain totals are not out of the question.
Flooding is a big concern because the storm will be moving very slowly - almost stationary - because there are no strong steering currents to push it along. Harvey is in an area between two high pressure systems.
The high pressure system to the east is helping steer Harvey towards the Texas coast. As soon as Harvey makes landfall, an area of high pressure with a northwest flow will keep it near the coast. Harvey will be stuck between these opposing flows. Eventually one of the high pressure systems will dominate steering the storm.
There are three possible outcomes for Harvey. After sitting along the coast for a few days, the storm could drift west, north or east. The forecast cone (forecast track) looks like a big circle in Texas. It covers a large area along the Texas coast, this is to take into account all of the potential paths and areas that will be impacted by the storm.