LAKE CHARLES, La. — Tropical Storm Barry is slowly strengthening in the Gulf of Mexico, and Louisiana is bracing for "life-threatening" rainfall. 

The National Weather Service in Lake Charles is warning of 15 to 20 inches of rain in parts of Southwest Louisiana as Tropical Storm Barry makes landfall Saturday. 

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Barry could strengthen and reach hurricane status before coming ashore near Morgan City, Louisiana. Heavy rainfall amounts are forecast for St. Mary, Iberia and lower St. Martin Parishes. 

"People will be trapped in homes due to the flood waters," the NWS Lake Charles said in a news release Friday. "Storm surge over three feet is expected for coastal sections of Vermilion, Iberia and St. Mary Parishes."

A storm surge warning is in effect for parts of Vermilion, Iberia and St. Mary Parishes. 

Tropical Storm wind speed probabilities with Barry
Tropical storm-force winds are likely in south central Louisiana Saturday
NWS Lake Charles

Downed trees and power lines are the biggest concern Saturday and Sunday. Isolated tornadoes are also possible along the path of the storm. The strongest winds and wind gusts are expected from Cameron Parish eastward to Morgan City, Louisiana. 

Beaumont could see 2-3" of rain from the tropical storm. Cameron Parish is forecasting 4-6" of rainfall with moderate flooding expected. 

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"Based on the current forecast track, hurricane-force winds are not expected in southeast Texas," the NWS said Friday.