On the eve of battle, watching weather becomes a mission-critical task

ABOARD THE USS CONSTELLATION-Petty Officer Third Class Pedro Rodriguez climbs up two ladders, puts on his helmet and snaps his goggles in place. He opens a hatch door and steps out onto the flight deck of the aircraft carrier. Amid rows of fighter planes under a nearly full moon, Rodriguez looks a little out of place as he moves slowly, gazing at four-foot waves and staring at streaked clouds not thick enough to hide the stars above the Persian Gulf.

"It's already changed," says Rodriguez, a weather observer for the Constellation's Meteorology and Oceanography Office, making mental notes as he observes the night's conditions during one of the two dozen weather observations he conducts during the course of his12-hour shift. On some shifts, Rodriguez will launch weather balloons from the rear of the ship. At other times, he'll carry hand-held devices that measure the wind speed or temperature. And on many occasions like this one, he'll simply rely on his senses to check up on Mother Nature.

Back inside and a few decks down, Rodriguez will feed his observations into a mainframe computer that will combine his readings with those taken by other observers and unmanned sensors aboard the ship and throughout the Gulf region. Then, relying on satellite imagery and computer models from Fifth Fleet headquarters supercomputers in Bahrain, the carrier will come up with a forecast even more detailed than those found on the Weather Channel.

If the United States goes to war with Iraq, those projections will play a key role in determining how and when planes will be launched from the aircraft carrier, what bombs will be used and what altitude the munitions will be dropped from. "Weather is a factor in every operation," says Lt. Cmdr. David Ruth, the Constellation's meteorology and oceanography officer, who estimates the ship's weather office provides about 400 briefings a month to everyone from the ship's navigators-who need to know wind speeds so they can steer the ship in the right direction to provide maximum lift to aircraft-to pilots, who receive a weather update before every mission.

Each U.S. aircraft carrier has a Meteorology and Oceanography Offices. The weather office does everything from tracking the lunar calendar to estimating how long a man overboard could survive in the water. An officer and a senior chief petty officer manage the Constellation's weather shop, while the watching and predicting is done by their trained staff of four forecasters and 10 weather observers. Everyone in the weather office has a security clearance for handling classified information.

Rear Adm. Barry Costello, commander of the Constellation Battle Carrier Group, turned to the weather office last week when a nasty sand and dust storm reduced visibility to zero, forcing the carrier to halt flight operations for several hours and divert seven aircraft to land in Bahrain for an overnight stay. One of Costello's first questions as the dust settled was to ask the weather office if the Gulf region was entering a season of sandstorms.

Ruth says sand and dust storms are more likely to occur during the spring, but he said last week's storm was a rare event. The storm was generated by strong winds sweeping over the salt and dust plains of the Tigris and Euphrates rivers in Iraq and blowing the sediment out over the Persian Gulf.

In the weeks ahead, Ruth says, troops in the region will see temperatures rise from highs in the 70s during the day and 60s at night to temperatures that will top out in late April at well over 100 degrees during the day, causing hazy flying conditions through the summer and early fall.

One of the region's key meteorological events, known as the 40-day shamal ("north" in Arabic), is fast approaching as well. From late May to early July, the shamal produces strong, steady winds from the northwest that raise the risk for dust and sand storms and lead to higher seas. The strong winds are actually good for the carrier, Ruth says, because they make it easier to launch aircraft.

Military planners also are closely tracking the stages of the moon, to determine whether troops moving at night will be able to operate undetected in the darkness. A full moon began on Monday, but by early April there will be no moon. Ruth however, says weather reports and the stages of the moon are never the deciding factor in determining when to launch a military operation.

"The United States military is an all-weather, all-season machine," he says.