Natural-gas futures rose slightly Thursday as traders watched the progress of a tropical storm in the Gulf of Mexico and waited for weekly storage data.

Natural gas for September delivery recently rose 1.1 cents, or 0.3%, to $4.329 a million British thermal units on the New York Mercantile Exchange.

Futures began the session flat, but picked up some steam as news of oil-and-gas producers shutting down some production in the Gulf rolled in.

Tropical Storm Don, the first major storm in the Gulf of Mexico for the season, has brought some subdued reactions from the market as the storm tracks toward refineries in the region.

"We might be under-reacting a little bit," said Phil Flynn, an analyst with PFG Best in Chicago, Ill.

The storm may not be as supportive of prices because shale gas production has reduced dependence on the Gulf. Wells there account for a little more than 7% of natural-gas production.

Flynn said he wouldn't take the storm too lightly.

"[Tropical Storm Don] could become an issue as the day goes on," he said.

Though the storm and recent hot weather patterns are supportive of prices, "well-supplied markets feel little pressed to respond to the temporary factors that may have only limited sway on balances," analysts with Barclays Capital said in a note to clients.

Still, producers in the Gulf have been evacuating nonessential personnel as a precaution, and now Exxon Mobil Corp. (XOM) has said it is shutting down some oil and gas output because of the storm.

The storm is expected to reach the Texas coast early Saturday, the National Hurricane Center said.

Rain from the storm is expected to bring relief from some of the heat in the state, and this would likely reduce gas-fired power demand in the region, analysts with Canaccord Genuity said in a client note.

Above-normal temperatures remain in Texas through MDA EarthSat Weather's 11- to 15-day forecast. Next week "much above" normal temperatures are expected for the Plains and Midwest, the private forecaster said.

While traders keep an eye on the weather, they are also anticipating the Energy Information Administration's storage report. A heat wave last week across the eastern U.S. has some traders and analysts predicting a smaller injection compared to previous weeks.

The report, due at 10:30 a.m. EDT, is expected to show an inventory build of 41 billion cubic feet, on average, during the week ended July 22, according to analysts surveyed by Dow Jones Newswires. That is above last year's 31-bcf injection and below the five-year average build of 49 bcf.

Injections below predictions often lift prices, while those that exceed expectations typically push prices lower. Last week futures fell after a slightly smaller-than-expected 60-bcf build, however.

Natural gas for next-day delivery at the benchmark Henry Hub in Louisiana recently traded at $4.4350/MMBtu, according to IntercontinentalExchange, down 2.5 cents from Wednesday's average. Natural gas for Friday delivery at Transcontinental Zone 6 in New York traded at $4.92/MMBtu, down 0.95 cent from the average a day earlier.