Coastal Flood Watch Issued for Suffolk, Middlesex and Monmouth Counties; High Tides and Wind Shift Raise Flooding Risk

The National Weather Service has released a coastal flood watch for multiple counties on the Long Island and New Jersey coasts, warning of possible inundation and travel disruptions this weekend. The coastal flood watch is timed to high-tide cycles and highlights an elevated risk of roadway flooding and potential structural damage in vulnerable shoreline areas.

Coastal Flood Watch — What happened and what’s new

On Friday at 3: 50 p. m. ET the National Weather Service issued a coastal flood watch covering Middlesex and Monmouth counties, valid from Sunday at 9 p. m. ET until Monday at 5 a. m. ET. one to two feet of water above ground level is possible in low-lying areas near shorelines and tidal waterways, and that additional coastal flooding could persist into Monday's high tide cycles.

Separately, on Friday at 4: 27 p. m. ET a coastal flood watch was issued for Suffolk County, valid from Sunday at 10 p. m. ET until Monday at 6 a. m. ET. Forecast guidance for that watch cited potential inundation of one and a half to two and a half feet above ground level in vulnerable waterfront and shoreline locations. The level of flooding in Suffolk County was described as highly sensitive to the timing of a wind shift from east-northeast to north gales relative to the time of high tide, and the forecast is expected to be refined in the following 24 hours. The agency also noted that ice cover in bays and harbors could worsen impacts to certain shoreline structures facing northeast to east.

The watches include explicit safety notes: many roads in coastal and bayside communities and along inland tidal waterways could be flooded or become impassable, and vulnerable structures may begin to experience damage at the projected inundation levels. Motorists and residents in flood-prone zones are advised to exercise caution and prepare to protect life and property.

Behind the headline

The immediate driver of the watches is the convergence of high tides with coastal wind and weather patterns that can push water levels above typical shore elevations. For Suffolk County, forecasters singled out the timing of a wind shift as a key factor that will determine the peak water level; for the New Jersey counties, guidance emphasizes broad risk to low-lying shore and bayside corridors. Ice cover in the region introduces an additional complication where present, with the potential to magnify localized damage to exposed shoreline structures.

Stakeholders include residents and businesses in low-lying waterfront neighborhoods, local emergency management officials responsible for road closures and evacuations, and travelers who may encounter impassable routes. Utilities and property owners in vulnerable areas face heightened exposure to electrical hazards if water enters basements or interior spaces.

What we still don’t know

• Whether either coastal flood watch will be upgraded to a warning before the period begins.
• The precise timing and strength of the wind shift in Suffolk County and how it will align with high tide.
• The extent and location of ice cover in bays and harbors and the degree to which it might exacerbate damage.
• Which specific roads or neighborhoods will become impassable if inundation reaches forecast heights.
• Whether additional coastal flooding will extend beyond the initial high-tide cycles into later tides.

What happens next

• Watch upgraded to warning: If water-level forecasts increase or timing of winds aligns with high tide, officials could issue coastal flood warnings for specific areas — trigger: refined forecast showing higher inundation.
• Moderate flooding with roadway closures: Predicted water levels materialize, producing widespread roadway flooding and localized property damage — trigger: observed tidal surge during peak high tide.
• Limited impacts: Higher water levels fall short of the upper forecast, leading to nuisance flooding but no major structural damage — trigger: windshift occurs earlier/later than forecast, reducing surge.
• Ice-related damage concentrated on exposed shores: Localized structural impacts where ice concentrates against northeast- and east-facing shoreline features — trigger: confirmed ice cover interacting with surge.
• Forecast refinement reduces uncertainty: Updated guidance issued within 24 hours clarifies expected inundation ranges and potential road closures — trigger: new model runs and observations of wind and tide timing.

Why it matters

Near-term practical effects include travel delays, road closures, and the risk of property and infrastructure damage in low-lying shoreline communities. The watches underline the need for residents in flood-prone locations to prepare by considering temporary relocation to higher ground, following evacuation orders if issued, and minimizing electrical hazards by disconnecting utilities and appliances when time allows. Public safety guidance emphasizes avoiding walking or driving through floodwaters — even relatively shallow, fast-moving water can sweep people and vehicles away — and seeking higher ground immediately if flooding begins.

Local emergency managers and residents will be watching tide cycles and refined forecasts closely in the hours before the watch periods begin to determine whether to escalate protective actions.