CHICAGO: U.S. corn futures rallied above $5 a bushel on Thursday to their highest level since August, while soybean futures touched a four-week high.

The gains came as farmers are in the middle of harvesting their crops, a time when the influx of fresh supplies normally pressures prices.

A severe drought that is disrupting grain shipments and slowing soybean plantings in rival exporter Brazil helped to propel markets higher, analysts said. Technical buying, along with gains in crude oil and weakness in the U.S. dollar, supported corn's rally, they said.

Still, forecasts for hefty U.S. corn supplies may limit further gains. When farmers have finished the harvests and all the grain has been delivered, the corn left in storage should exceed the amount that has sat in U.S. silos for seven years, according to the U.S. government.

"In the face of a 2 billion bushel-plus carryout, that's what makes me wonder how far we can really go," said Tomm Pfitzenmaier, analyst for Summit Commodity Brokerage in Iowa.

Most-active corn futures at the Chicago Board of Trade rose 13 cents to $5.05 a bushel and touched their highest price since Aug. 21 at $5.05-1/2 a bushel.

There was unconfirmed talk in the market of China looking to the U.S. Pacific Northwest (PNW) for corn purchases, brokerage CHS Hedging said.

"Corn put together quite a performance today on technical buying," CHS Hedging said.

CBOT wheat ended up 13-3/4 cents at $5.94 a bushel and hit a three-week high at $5.94-1/2.

CBOT soybeans jumped 4-1/2 cents to $13.15-1/2 a bushel after hitting its highest price since Sept. 21 at $13.17-3/4. A rally to July highs in soymeal futures helped support soybeans, traders said.

"Meal's been on a tear here," said Matt Wiegand, commodity broker for FuturesOne.

Weekly U.S. soybean, corn and wheat export sales for 2023-24 were within analysts' estimates. Difficult logistics in Brazil could create a short-term window of opportunity for improved U.S. corn exports, a broker said. (Reporting by Tom Polansek in Chicago. Additional reporting by Naveen Thukral in Singapore and Gus Trompiz in Paris; Editing by Subhranshu Sahu, Will DunhamD, Sherry Jacob-Phillips, Jonathan Oatis and David Gregorio)