GRAINS-U.S. soybean, soymeal futures extend weather-driven rally

(Recasts, updates with U.S. trading, adds new analyst quote, changes byline/dateline; pvs MANILA/PARIS)

CHICAGO, Feb 15 (Reuters) - U.S. soybean futures rose on Thursday to their highest level since July 25 as an ongoing drought in key exporter Argentina underpinned prices.

Soymeal futures, which hit a 19-month high, were headed higher for the eight straight session as fears have mounted that Argentina will struggle to meet its export commitments for the animal feed. The most-active Chicago Board of Trade soymeal futures contract has risen 14 percent during the streak.

"Spot beans keep churning higher a penny or two at a time," Matt Zeller, director of market information at INTL FCStone, said in a note to clients. "Overall, beneficial precipitation (in Argentina) is seen as remaining very limited with warm temperatures stressing (the) crop as well."

Corn futures weakened on technical selling after bumping up against the six-month high hit earlier this week. But concerns about the South American crop limited the declines.

Wheat was mixed, with Chicago Board of Trade soft red winter wheat contracts easing on profit-taking, while K.C. hard red winter wheat futures rose on concerns that parched soil in the U.S. Plains will reduce the size of the harvest there.

At 10:12 a.m. CST (1612 GMT), CBOT March soybean futures were up 2-1/4 cents at $10.19-1/2 a bushel. Prices for the most-active contract hit a high at $10.22-3/4 a bushel.

CBOT March soymeal was $2.70 higher at $372.60 a ton, peaking at $374.90 a ton, the highest for the most-active contract since July 15, 2016.

Argentina could harvest fewer than 50 million tonnes of soybeans in the 2017-2018 crop year, the lead analyst at the Rosario grains exchange said on Wednesday, as a prolonged drought looks set to continue harming yields.

The dryness in the heart of Argentina's Pampas grains belt is likely to persist through the second half of February, climate experts said.

"This is unlikely to have been the last downward revision. Pessimistic observers are already warning of a crop volume in the low 40 million tonnes range," Commerzbank said in a note.

CBOT March corn was half a cent lower at $3.66-3/4 a bushel, not far below Tuesday's high of $3.68-1/2.

Chicago March soft red winter wheat was down 1 cent at $4.54-3/4 a bushel. K.C. hard red winter wheat was 3-1/4 cents higher at $4.73 a bushel. (Additional reporting by Manolo Serapio Jr. in Manila and Sybille de La Hamaide in Paris; Editing by Alexander Smith and Paul Simao)