Updated 4:50 p.m. ET

(Bloomberg) -- Harvey, which could strengthen into thefirst hurricane to strike Texas since 2008 thisweek, forced workers to be evacuated from Gulf of Mexicoplatforms, sent cotton rallying and has airlines preparing forflight disruptions.

Related: 9 practical steps for hurricanepreparation

Currently a tropical depression, Harvey was 470 miles (756kilometers) southeast of Port Mansfield, Texas, with top winds of35 miles per hour, the U.S. National Hurricane Centerr said in itslatest advisory. It could develop into a hurricane just beforelandfall.

“It could intensify right up to landfall on Friday,” said JeffMasters, co-founder of Weather Underground in Ann Arbor, Michigan.“I expect a Category 1 hurricane at landfall, but I cannot rule outa Category 2.”

Refineries in path of heavy rainfall

The Gulf Coast from Corpus Christi, Texas, to Lake Charles,Louisiana, is home to nearly 30 refineries — making up about 7million barrels a day of refining capacity — and is in thepath of heavy rainfall expected to start as early asFriday. Flooding poses risks to operations, while torrentialrains can shut units and cause supply disruptions.

Fuel supplies in the region may be tightened further by other,unrelated refinery outages. Phillips 66 began a plantwide shutdownof its Lake Charles, Louisiana, refinery late Tuesday after itspower supplier warned of a high potential for electrical failure,according to a company statement. Houston wholesale conventionalgasoline rose 1.9 percent to $1.5926 a gallon Wednesday, datacompiled by Bloomberg show.

Reduction of crude oil imports

“Biggest impact of this storm will be a significant reduction ofcrude oil imports into the Texas Gulf Coast, resulting inrefineries cutting crude rates,” Andy Lipow, president of Lipow OilAssociates in Houston, said by email. “There will also be asignificant impact on petroleum product exports impacting suppliesinto Mexico.”

Related: A millennial's guide to surviving ahurricane

Ike in 2008 was the last hurricane to hit Texas, said DennisFeltgen, spokesman for the National Hurricane Center. Ike struck asa Category 2 storm on the five-step Saffir Simpson scale.

Exxon Mobil Corp. said it’s cutting output at its Hooverproduction platform in the Gulf of Mexico ahead of the storm. Thecompany’s also working on plans to evacuate staff in stages fromoffshore facilities that will be in the path of the storm, SuannGuthrie, a spokeswoman, said by email.

Anadarko Petroleum Corp. said Tuesday it’s removing nonessentialstaff from some production platforms in the Gulf of Mexico inresponse to weather conditions. Cheniere Energy Inc. “activated”the severe weather team at its Sabine Pass LNG export terminal inLouisiana, Eben Burnham-Snyder, a spokesman, said by email. “Atthis time no production impacts expected.”

Heavy rains for parts of Texas & Louisiana

Along the coastline, seas could rise 4 to 6 feet above ground leveland from 10 to 15 inches of rain will probably fall across parts ofTexas into Louisiana, the hurricane center said. Some areas couldget as much as 20 inches of rain.

“It is going to be a wet one,” Masters said. “It is not going tomove fast after landfall and that is going to cause big trouble”from flooding rains.

The current track calls for the storm to land in southeasternTexas and then turn toward Houston. Masters said at least onecomputer-forecast model shows the storm heading back into the Gulfof Mexico early next week before coming ashore in Texas again.

Making preparations

Both Oncor Electric Delivery Co. and CenterPoint Energy Inc. saidthey expect Harvey to make landfall Friday and are makingpreparations. American Electric Power Co. is making arrangements tobring in outside repair crews if they’re needed, Larry Jones,spokesman, said in a phone interview Wednesday.

Cotton rallied on speculation the storm will threaten U.S.crops. On ICE Futures U.S. in New York, cotton for Decemberdelivery climbed 1.6% to settle at 68.89 cents a pound afterearlier reaching the highest since Aug. 10.

Related: 4 ways to prevent business interruption from anatural disaster

“Some concern is developing” regarding the storm impact and theheavy rains expected in Texas, Louis Rose, director of research andanalytics at Rose Commodity Group in Memphis, Tennessee, says byemail.

Mansfield Oil Co., a Georgia-based fuel distributor, said itraised its storm conditions to a red alert. “Heavy rainfall isexpected in this region, which could impact refinery operations andtrucking logistics in the region,” the company said by email.

Rebooking flights

American Airlines Group Inc. is allowing people traveling throughHouston and nine other cities on certain dates to rebook theirflights without a fee because of the storm. United ContinentalHoldings Inc. is offering the same in eight cities, while Delta AirLines Inc. is offering a similar waiver for Houston flights.

Related: What if Hurricane Andrew happenedtoday?

Copyright 2018 Bloomberg. All rightsreserved. This material may not be published, broadcast, rewritten,or redistributed.