Four Things to Know About Tropical Storm Harvey

What is now Tropical Storm Harvey is inland over Texas where it's expected to bring life-threatening conditions well into the week ahead.

(MORE: Hurricane Central)

Here's what you need to know about this dangerous storm.

1. Harvey's Stall Has Begun

Harvey made landfall Friday night, but its forward progress has now come to a crashing halt. 

The National Hurricane Center expects Harvey to meander near the Texas coast through much of this week while weakening with time.

Harvey's long-awaited stall is due to weak steering currents in the upper atmosphere. For the next several days, Harvey will be caught in between a large area of high pressure in the western states and another area of high pressure extending from the western Atlantic into the Gulf of Mexico.

A southward dip in the jet stream across the eastern states is expected to miss out on ushering Harvey away, allowing the tropical cyclone to stall for days.

(MORE: Three Reasons Slow Moving Tropical Storms and Hurricanes Are the Worst)

2. Harvey's Stall = Huge Flood Threat

The biggest concern with Harvey going forward is the torrential rainfall that will soak parts of the middle and upper Texas coast. Rainfall accumulations through next week could be around 40 inches in parts of Texas, triggering devastating, long-lasting flooding.

Some coastal Texas cities could receive a vast majority of their annual rainfall in less than a week from Harvey. 

Additionally, coastal flooding could last several days and multiple tide cycles along the Texas and southwestern Louisiana coasts.

The strongest winds will gradually wind down, but they will remain gusty for many days. Those winds in combination with saturated soil could down additional trees.

One other concern is the risk for tornadoes the next several days, from the middle and upper Texas coast to southwest Louisiana.

3. Harvey is Strongest Hurricane to Strike Texas in Decades

Harvey is the first Category 4 hurricane to make landfall in Texas since Hurricane Carla in 1961. Carla roared ashore on the northeast part of Matagorda Island which is just up the coast from where Harvey made landfall.

The last hurricane of any intensity to make landfall in the Lone Star State was Hurricane Ike in 2008, which came onshore near Galveston as a Category 2 hurricane.

Ike brought extensive damage from strong winds, storm surge and heavy rainfall to Hispaniola, the Turks and Caicos Islands, southern Bahamas, Cuba and the U.S. Gulf Coast. Hurricane Ike also was responsible for 21 deaths in Texas, Louisiana and Arkansas.

4. First U.S. Category 3+ U.S. Landfall Since 2005

Harvey is the first Category 3 or stronger U.S. hurricane landfall since Wilma in southwestern Florida during October 2005.

In addition, Harvey is just the fourth hurricane to make landfall in the U.S. as a Category 4 or stronger since 1970, according to Dr. Phil Klotzbach, a tropical scientist at Colorado State University.