(Adds latest prices and USDA export sales data, changes byline/dateline; previous PARIS)

* Hot, dry weather expected to stress Argentina soy

* Rains continue to delay Brazil soy harvest

* Weekly U.S. corn export sales miss expectations

CHICAGO, March 4 (Reuters) - U.S. soybean futures climbed on Thursday as adverse weather across South America fueled concerns about a short-term supply crunch.

Traders focused on Argentina, a major exporter of soymeal and corn, as hot and dry conditions are expected to continue over the next week. The dryness will stress second-crop soybean growth, according to weather firm Maxar.

In Brazil, the world's top soybean exporter, rains delaying the soy harvest are expected to continue through the weekend, Maxar said.

The unfavorable weather reinforced supply concerns as record U.S. soybean crushings and exports are projected to shrink American stocks of the oilseed to a mere 9-1/2 day supply ahead of the next North American harvest.

The U.S. Department of Agriculture will update its estimates on global supplies and demand in a monthly report due on Tuesday.

"With the market looking for a possible hot and dry weather stress in Argentina or for the USDA to further tighten U.S. old-crop ending stocks, the trade needs a bullish punch to up prices," said Jerry Gidel, analyst for Midland Research.

Most actively traded soybean futures on the Chicago Board of Trade were up 12-1/2 cents $14.20 a bushel by 12:20 p.m. Central (1820 GMT) and earlier touched a session high of $14.38. The most-active contract last week reached $14.45-3/4 a bushel, the highest price since June 2014.

To meet growing demand for soybeans, commodities trader Cargill Inc is expanding processing capacity at two large Midwest crush plants and increasing efficiency at five other U.S. facilities.

The USDA in a weekly report said U.S. soybean export sales totaled 533,400 tonnes for the week ended on Feb. 25, within analysts' estimates for 100,000 to 800,000 tonnes.

Weekly U.S. corn export sales totaled 154,700 tonnes, well below the low end of analysts' estimates for 450,000 to 1.05 million tonnes.

Most-active CBOT corn futures were up 1-1/2 cents at $5.36-3/4 a bushel, while wheat was down 2-1/4 cents at $6.53-3/4 a bushel.

(Reporting by Tom Polansek in Chicago, Colin Packham in Sydney and Sybille de La Hamaide in Paris; Editing by David Goodman and Dan Grebler)