The National Oceanic and Atmospheric Administration does more than forecast the weather: It monitors pollution, makes nautical and aeronautical charts, promotes fishing and protects sea turtles. But make your own observations: It's NOAA Week in Baltimore this Saturday through October 31.

The center of this educational extravaganza will be the NOAA-SERVES TENT set up at the Inner Harbor, where NOAA agencies will have a number of free exhibits. The Earth Satellite Service shows what the path of a hurricane looks like from above the clouds. A computer in a Weather Service exhibit tells what a pilot can expect on a route you choose. The National Ocean Survey traces the development of tidal surveys. And everything you need to know about the coasts of the Chesapeake Bay, you can learn from Coastal Zone Management.

Outside the tent, demonstrations start at noon each day. Launching a weather balloon is so easy a child can do it, and one does. How to shuck oysters is taught by the Marine Fisheries Service. Lawrence the Talking Trout takes on any questions about NOAA you haven't already had answered inside the tent, and divers from the National Ocean Survey demonstrate diving equipment. They'll be diving from a NOAA research ship, the Mt. Mitchell, on Monday and Tuesday. The MT. MITCHELL is taking time off from a nautical charting survey (Ocean City, Maryland, to Cape Hatteras) to dock on the west shore of the Inner Harbor for Weather Week. Saturday through Tuesday from 10 to 3:30, the ship will be holding open house. THE PRIDE OF BALTIMORE will be there, too. This Saturday and Sunday, and October 30 from noon to 5, you can tour it where it's docked at the finger piers, visible from Harbor Place. If you're visiting on October 31, the last day of the weather fair, you can watch the ship depart for the Pacific Northwest. Ceremonies start at 2. A re-creation of an 1812 clipper schooner, the Pride has been anachronistically outfitted as a marine-weather observation vessel and on the trip will report weather for NOAA. Baltimore really is going all out for this. As part of its Man and the Sea exhibit, the NATIONAL AQUARIUM is displaying rare objects: a sealskin doll, canned seal meat, green turtle soup, tortoise-shell jewelry from a hawksbill turtle and two scrimshawed sperm whale teeth. To be exact, these specimens and others in the exhibit have all been seized by the National Marine Fisheries Service as violations of the Marine Mammal Protection Act or the Endangered Species Act. Admission to the Aquarium is $4.50 for adults; $3.50 for students 13 to 18 and adults over 60; $2.50 children 12 and under; free for 3 and under. And the MARYLAND SCIENCE CENTER will be showing award-winning NOAA films. Here's the schedule: now through November 5, "Down to the Monitor," about the underwater exploration of the Civil War ship Ironcladcd10, and "Neosho," on the destruction by tornado of a Missouri town in 1977; November 6 to December 3, "The Great American Fish Story," on commercial fishing; December 4 to January 2, "Global Weather Experiments," on worldwide cooperation in weather matters. Showtimes are Monday through Friday at 3, and Saturday and Sunday, 2 and 4. A new "NOAA Serves" exhibit outside the theater gives still more information. Admission to the Science Center includes the movie; $3 for adults, $2 for adults over 60 and students through college, and $1.50 for children under 12. FORT McHENRY also is participating, with an exhibit on local weather in the 19th century. Admission is free. To get there, go east on Light Street past the Maryland Science Center, then turn left on Fort Avenue. For something else to check out while in Baltimore, LEXINGTON MARKET is celebrating its 200th birthday this week. Saturday night at 8, you can do what you always do at the market -- eat your way through. It's $15, and there'll be square dancing, co Dedicating a new arcade, the market will be open this Sunday for a change, and there'll be a neighborhood cooking competition. A parade starts at 2 from City Hall (100 North Holliday) and winds its way to the market (400 West Lexington), where cooking starts at 3:15. Jugglers and musicians will add to the revelry. You don't need a weatherman to know which way the wind blows. But you can visit one anyway at the NATIONAL WEATHER SERVICE in Baltimore-Washington International Airport. The service is holding open house Thursday through October 31 from 1 to 4. The office is just a few rooms, but it's interesting to see weather forecasters at work, combining simple science with computers. Visibility is still determined by how far the weatherman can see -- but weather maps appear on a terminal screen with the push of a button. Among other things, the meteorologists keep a continuous record of sunshine (a green light goes on when the sun comes out) and measure the height of clouds. They give pre-flight briefings to pilots and send out hourly observations. This office operates two radio stations, one for Hagerstown and one for Baltimore. The meteorologists who announce on NOAA Weather Radio don't have to own beautiful voices, says Bill Lavris, who predicts weather at BWI. "In my whole life, I have never gotten any fan mail, and I don't expect any," he says. But one weather bureau he worked for received and collected 30 years' worth of letters from one man: "He didn't think we were predicting weather," says Lavris. "He thought we were producing it." In his letters to the weather bureau, the man would make such demands as, "Let the kids have some fun. We need some snow." Maybe NOAA Week can clear up some of this kind of confusion. TO THE TENT THAT NOAA BUILT To get to Baltimore's Inner Harbor, take the Baltimore-Washington Parkway north. It becomes Russell Street. Proceed on Russell to Pratt Street. Turn right on Pratt and go seven blocks to Light Street.