El Nino weakens in Pacific.

The El Nino warning that wouldn't go away last year is finally showing signs of packing its bags, according to an advisory issued last month by the U.S. weather service's Climate Analysis Center. But having been fooled last year by similar developments, forecasters hestitate to say that the current El Nino has gone for good.

El Nino devloped once or twice a decade when a huge pool of warm water spreads across the equatorial Pacific and the normal westward-blowing winds weaken. Such changes re-route typical air-circulation patterns and upset weather around much of the globe.

The recent El Nino started in 1991 and seemed to have runs its course by mid-1992, prompting predictions of a return to normal or even cooler-than-normal conditions by year's end. However, the warning regained strength during the second half of 1992 and the first half of 1993. Because El Ninos shift heat and moisture eastward from the western Pacific, the warming's resurgence last year dried out Indonesia and brought heavy rains to South America's Pacific coast this year. It also played a role in blocking the rains that normally wash northeast Brazil from February through May, says Vernon E. Kousky of the Climate Analysis Center.

Hints of the El Nino's imminient departure appeared in July when sea-surface temperatures started dropping in many parts of the tropical Pacific. As yet, however, the winds and atmospheric pressure in the Pacific have not returned to normal, making meterologists leery about forecasting an end to the current El Nino.