A coastal flood watch has cast a long shadow over Jacksonville this weekend, as a potent nor'easter teams up with astronomically high tides to push dangerous water levels into streets, neighborhoods, and shorelines across the region.

The watch stretches across a wide swath of Northeast Florida, covering the Atlantic coast, the Intracoastal Waterway, and the entire St. Johns River Basin -- a sprawling network of waterways that locals know can turn treacherous in a matter of hours.

The timing could not be more unsettling.

Flooding is expected to peak around high tide Saturday evening, with the most severe water levels anticipated during Sunday and Monday morning tidal cycles, when moderate to major tidal flooding becomes increasingly likely.

Along the Atlantic coast and Intracoastal Waterway, water could surge roughly two and a half to three and a half feet above normally dry ground -- enough to push into coastal roads, parking lots, and even the ground floors of vulnerable structures.

Duval and St. Johns county officials are urging residents to move vehicles out of flood-prone zones, secure patio furniture and trash cans, and avoid any contact with standing or moving floodwaters.

The familiar Turn Around, Don't Drown warning carries extra weight this weekend, as even shallow moving water can knock a person off their feet and sweep a vehicle downstream.

Inland areas along the St. Johns River and its tributaries are not spared either, with water levels potentially rising two to three feet in historically flood-prone neighborhoods including Riverside and San Marco.

Coastal communities face a separate but equally serious threat from nor'easter beach erosion, with significant sand loss expected at beaches across the First Coast as relentless northeast winds batter the shoreline.

The surf is outright dangerous.

Breaking waves of seven to eleven feet, a high risk of rip currents, and a Gale Watch covering marine waters through Monday -- with offshore seas reaching ten to sixteen feet -- make any ocean activity deeply inadvisable.

Wind gusts reaching up to 45 miles per hour are possible along the coast from Saturday afternoon through Sunday, raising the risk of downed trees, damaged power lines, and scattered outages across the region.

The City of Jacksonville's Emergency Preparedness Division is actively coordinating with the National Weather Service to track conditions and respond quickly as impacts unfold.

Residents in low-lying areas should take this watch seriously -- the convergence of a nor'easter and elevated tides is the kind of combination that can escalate rapidly.

Officials stress that barricades around flooded roads must be respected and that alternate routes should be identified in advance.

Anyone near the beaches or waterways this weekend is urged to exercise extreme caution and stay well clear of the surf until conditions improve early next week.