Harvey track 4 p.m. Aug. 24, 2017

Hurricane Harvey's forecast track as of 4 p.m. Thursday.

Graphic via NHC

LATEST: Click here to read more about a change in Hurricane Harvey's forecast track late Thursday.

Forecasters are confident Hurricane Harvey will make landfall late Friday or early Saturday near Corpus Christi, Texas. What they're uncertain about is what Harvey will do thereafter.

In its 4 p.m. advisory Thursday, the National Hurricane Center said the models "have trended toward showing Harvey moving slowly eastward" next week toward Louisiana after it strikes Texas, "but it's too early to know if the center will remain over land or re-emerge over the northwestern Gulf of Mexico."

"The track guidance is very tightly clustered for the first 36-48 hours, which covers the period of landfall, but then there is much greater spread in the models after 48 hours when Harvey is forecast to slow down. Such guidance is usually an indication that the cyclone will move very little, which is reflected in the official forecast."

Before it makes landfall, Harvey is expected to reach major hurricane status, bringing winds of possibly 125 mph. Devastating and life-threatening flooding is expected across the middle and upper Texas coast from heavy rainfall of 15-25 inches, with isolated amounts as high as 35 inches, from Friday through next Wednesday, the NHC said.

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