NEW YORK, April 20 (Reuters) - U.S. cotton futures tumbled
again on Wednesday, with most of the decline in nearby
contracts attributed to switches ahead of first notice day, and
some brokers said negative technical charts and ample supplies
anticipated in the global market have also pressured prices.

While a dry spell in the Southern United States, especially
top U.S. growing state Texas, put a floor under price declines,
a rain shower could lead to even steeper drops.

'It's really dry out here in West Texas, and if the crop
gets a good rain prices will get whacked. At least 10 to 15
cents of the price is dry weather,' said Jobe Moss of MCM Inc
in Texas.

The front-month May cotton contract on ICE Futures
U.S. tumbled 6.65 cents to finish at $1.8377 per lb.

Most-active July was also sharply lower, falling 4.10
cents to end at $1.6740 per lb.

New-crop December cotton settled with a small 0.29
cent gain at 99.90 cents per lb.

Brokers were somewhat puzzled about the degree of the price
drops. But, with first notice day for May futures approaching
on Monday and one more day left to trade the contract with
markets closed for the Good Friday holiday, many players
holding May cotton have been anxious to sell out all week.

'The whole thing has been the May/July switch. The switch
has gone from 4 or 5 cents up to 19 cents. And we're talking
about switching from old crop to old crop, which is crazy,'
said Moss.

Technically, both May and July futures also look negative.
Both formed a head and shoulders top, whose necklines were
definitively broken on Wednesday.

Moss said the July neckline break pointed to a decline that
could lead it down to about $1.48 a lb.

Moreover, ample crops from the Southern Hemisphere were
expected to come to market soon, with large supplies
anticipated from Australia, Argentina and Brazil.

The decline in U.S. cotton prices has partly been a
reaction to the additional supplies expected in the global
market.

In addition, U.S. projected plantings for cotton has been
increased to 12.6 million acres in the 2011/12 crop year from
10.9 million acres in the 2010/11 crop year, which would only
exacerbate the potential for over supply, brokers said.

Trading volume slipped to 26,859 contracts, down from
34,202 lots that changed hands on Tuesday, according to Thomson
Reuters preliminary data.

A mostly dry weather outlook for Texas over the next five
days, with temperatures near to above normal, could compromise
the yield in the biggest U.S growing state.

Weather forecaster DTN Telvent said more rain was needed in
cotton growing regions of the U.S.

Open interest in the cotton market dropped to 172,140 lots
from 182,494 lots as of April 18, ICE Futures U.S. data show.
May open interest stood at 21,802 lots by the end of April 19.