Summer marks the end of the summer doldrums and the beginning of fishing's second season. Cooler nights will bring better fishing. Here ar the highlights of the fall predictions.

Lake Anna will probably produce the best late-season bass fishing. Tom Goodwin, who takes creel censuses at Sturgeon Creek Marina lake, says that the bass should start moving about as the wart cools, probably around mid-September. "Fall is our best season," Goodwin said last week. "The fish feed heavily because they're putting on fat for the winter." The feeding usually lasts until mid-November. Because the fish will be moving about with changing water temperatures, Goodwin, recommends spinner baits, crank baits and top-water baits in the shallows and coves during the early morning and later afternoon when the water is cool, and plastic worms deep when the water warms at midday.

Upstream in the Potomac, smallmouth bass have been slow since mid-July, except for below Harpes ferry. The white miller hatch was sporadic, and high water fouled the river. The result was slow fishing during the late summer. Cool weather and stable water conditions should change this, according to Carl Rauer, who runs the Potomac Fly Shop near Hagerstown. "Look for the bass in the holes and deep water below the rifels. White, yellow and black muddler minnows should turn some fish," he says.

Chesapeake Bay fishermen should look to the lower part of the bay this fall for blues, sea trout and rockfish. Migrating south, the bules will leave the middle bay around mid-October and leave the lower bay by Thanksgiving. The fall migration usually reverses the spring pattern. Big blues, 8 to 12 pounds, usually enter the bay first in the spring, followed by five- and six-pounders, and then one- to three-pounders. But the small blues leaves first in the fall, so you can expect to see more of those giant, toothy "choppers" that opened the season last May.

The fall run of sea trout is more difficult to predict. Trout school in the spring when they enter the bay. The schools fragment in the summer and then regroup in the fall before leaving the bay. Last year the spring schools were large and long-lasting, but when the fish separated they were almost impossible to catch, and the fall run was not as good as the spring run had led people to expect. This year the spring run was good, but not spectacular as last year. But the fish remained easier to catch this summer, so it may be that the schools will regroup better and provide a better fall run. Traditional hotspots are. The mouths of the Potomac and the Patuxent rivers, off Point Lookout, from buoys 50 to 54, Tangier Sound, and Hooper Island Strait.

Rockfish move south in the bay and downsteam in the rivers during the fall. The rockfish in the rivers, mostly under 10 pounds, will school. Since they will be on the move, you have to know where the schools are. This is hit-or-miss fishing, and I recommend calling first to Tackle Box in Lexington Park. Last year trolled small, unweighted white or yellow bucktails were effective along the shorelines of the lower Potomac and Patuxent. One of the best areas last fall was near the powerplant at Morgantown.

Trout fishermen will do best to look toward southern Pennsylvania and the Shenandoah Park this fall, since Maryland streams are low. In southern Pennsylvania I would pick Falling Spring Run near Chambesburg, where the Tricorythodes mayfly hatch will continue to mid-October. Look for this minute black-bodies mayfly, size 22, over the rifles at about 10 a.m. Barry Serviente of Angler's Art in Georgetown also recommends hoppers throughout September on the lower section of Big Spring near Newville, Pa.

The Shenandoah Park streams close October 15th because the brook trout will soon afterward be spawning. Until then most dry-fly patterns, in size 16, will take fish in the pools where the fish collect during summer's low water. During the fall these streams provide, in my opinion, the most charming fishing in the Washington area. The streams are pure, wild and remote as always. But the fish, though small, will wear their spawing colors: blue, orange and white. Even the smallest brook trout in your hand looks like a king's jewel.