New moon springs push fluke out of a hot bay and stack them at the inlet

Last week the bay did what bays do in the first week of July — it cooked. Great South Bay water pushed into the high 70s, touching 78.8°F in the shallow flats off East Moriches and Mastic, and that's above the comfort line for a flatfish that likes its water in the low 70s or cooler. What that does structurally is simple: it forces fluke out of the open bay and into anything with current and depth — the inlet throat, the Moriches channel edges, Tuthill Point drop, and the deeper cuts running out past Cupsogue. Warm, slack, shallow water pushes bait and predators alike toward the plumbing. That's exactly what's happened, and it's the single biggest driver behind everything I'm about to tell you.

This week the moon is doing its part to keep that plumbing working hard. We're building toward new moon springs, with peak tidal range hitting July 11-13. Bigger swings mean more water moving through the inlet on every stage, which means more exchange between that overheated bay and the cooler, cleaner ocean water sitting outside. I've been watching incoming tide temps at the inlet run several degrees cooler than the back bay — upwelled ocean water in the low 70s meeting bathwater at 78. That temperature seam right at the inlet mouth is where the bite lives right now, and it's going to sharpen as the tidal range grows into the weekend. Wind's been manageable, mostly light to moderate out of the south and southwest, keeping the surf line at Cupsogue fishable rather than churned. If that holds through the weekend, Friday through Monday sets up as the best structural window we've had since the June full moon — especially for stripers working the western sound-side flood into sunset, a pattern that hasn't been in play since last month.

Fluke fishing has genuinely improved, and I want to be straight about that because the last few weeks were mixed at best. The inlet drift on the outgoing tide — starting at the Coast Guard station and running the throat out past the jetty tips — has been giving up keeper fluke to 4 and 5 pounds on white Gulp Swimming Mullets rigged on 3/4-ounce bucktails, worked slow and bounced off the bottom in 15 to 22 feet. The key has been staying tight to the channel edges where the sand drops into that deeper cut — fluke are stacking on the lip, not out in the middle where the current runs too hard on the bigger tides. Cupsogue ocean side has also been worth the walk; surfcasters working incoming water with 4-inch chartreuse Gulp on a high-low rig off the second bar have been picking at fluke and the occasional weakfish mixed in, though the weakfish bite is spotty at best — a few 18 to 20-inch fish, nothing like a real run yet. I'm not going to oversell that one. Sixteen straight days of water above 70°F in these systems hasn't translated to consistent weakfish reports, and I think that threshold gets people's hopes up more than it should. Necessary, not sufficient — you still need bait stacked and the right tide stage, and I haven't seen that convergence yet.

Striped bass have been the more honest story. Inlet regulars are finding fish on the last two hours of the outgoing, working bucktails and swim shads through the rip where the jetty current collides with the bay flow — that standing wave off the north jetty tip has been holding fish in the 24 to 30-inch range, with a few better ones mixed in on bunker chunks fished on the bottom just inside the throat. Live eels after dark off Tuthill Point and the Smith Point side have also produced, particularly on the last two nights of decent tide push before the moon goes fully dark. If the western sound-side flood-into-sunset pattern that's opening up this weekend holds true to form, I'd expect some of that pressure to ease off the inlet as fish spread out to feed the last hour of daylight on the flood — worth knowing if you're deciding between an evening inlet session or working the bay-side flats instead.

Bluefish have been present but not thick — snapper-sized fish mixed with a few 3 to 5-pound choppers working bait pushed out of the bay on the outgoing, mostly caught incidentally by guys fishing bucktails for bass or fluke. Porgies are solid but unspectacular around the rock piles inside the inlet and along the Cupsogue rubble, standard high-low rigs with clam snapping fish in the 9 to 11-inch range — good action if you want steady bites over trophy size.

The wildcard this week is the ocean side pelagic watch. We're in the last days of the early-July bonito and Spanish mackerel window, and the signals line up — clean incoming water, warming inshore temps, bait pushed to the surface by the tide exchange. If a school works the rip off Cupsogue or swings past the inlet mouth on a clean incoming tide, small metal — half-ounce Deadly Dicks or Kastmasters — thrown into working birds is the move. I haven't had a confirmed hookup yet this week, but the conditions are as good as they've been all season, and I'd rather be ready with light tackle rigged than miss it scrambling.

Looking ahead: if the wind stays out of the south-southwest through the weekend and doesn't build past 15 knots, I'd fish the inlet outgoing for fluke Thursday and Friday morning, then shift to the sound-side flood at sunset Saturday through Monday when the springs peak. Have a fluke rod and a bass rod both rigged — this time of year the smart move on Moriches water is staying flexible between the two.