🌊 US Weather Warriors MarineCast — Monday, July 20, 2026
Small Craft Advisories are up across the Atlantic coastal waters, Delaware Bay, and the Chesapeake — plan around the wind, not through it.
Today on the Water: SCAs are in effect for the Atlantic coastal zones through Wednesday 6 PM, Delaware Bay through Wednesday midnight, and the mid-Chesapeake through Tuesday 5 AM. Winds pick up through tonight with channeling in the bay. Scattered showers and storms are in the forecast window, and radar already shows a cluster of convective cells 38–50 nm south and southeast of Cape Charles moving generally west toward the lower Eastern Shore.
Atlantic Coastal Waters (Lewes → southern VA coast): Expect building southerly flow under the SCA, with the strongest push arriving Tuesday night: SW 20–25 kt, gusts to 35 kt, seas 5–6 ft and occasionally to 9 ft. Watch for lightning risk offshore of the VA capes as those Cape Charles cells track westward toward the coast.
Delaware Bay: Under SCA through Wednesday midnight. Winds ramp Tuesday afternoon to S 15–20 kt with gusts to 25 kt, seas 2–3 ft, and showers with a chance of storms Tuesday night as SW winds hold 10–15 kt gusting 25.
Chesapeake Bay & Delmarva-facing Waters: NE winds turn SE this afternoon, then strengthen tonight with bay channeling — SCA runs through Tuesday 5 AM for the mid-bay zones. Peak comes Wednesday with SW 20–25 kt, gusts to 30 kt, easing to 15–20 kt by afternoon under showers.
Wind & Seas Outlook: Peak winds Tuesday night into Wednesday morning; highest Atlantic seas Tuesday night at 5–6 ft with 9-ft occasional.
Marine Alerts:
- Small Craft Advisory — Atlantic coastal waters, until Wed Jul 22, 6:00 PM EDT
- Small Craft Advisory — Delaware Bay, until Wed Jul 22, 12:00 AM EDT
- Small Craft Advisory — mid-Chesapeake Bay zones, until Tue Jul 21, 5:00 AM EDT
Best Window to be Out: This morning before the SE turn and evening wind ramp — get off the water by early afternoon, and stay clear of the lower VA coastal waters where radar cells are tracking onshore.
Worst Window: Tuesday night — SW 20–25 kt gusting 35, seas to 9 ft, storms.
Bottom Line: If you launch today, keep it short, close, and finished by mid-afternoon — the window narrows fast from here.
— US Weather Warriors #DelmarvaWeather #MarineWeather #BoatingWeather