Monster tides flooded Southern California’s coastline Tuesday, swamping waterfront neighborhoods and shutting down stretches of the Pacific Coast Highway.

The coastal chaos is expected to continue through Thursday, with forecasters warning that unusually high morning tides could bring more flooding to vulnerable beach communities.

In Orange County, flooding forced the closure of both directions of PCH between Warner Avenue and Seal Beach Boulevard Tuesday morning, according to Caltrans. Northbound lanes were also closed between Seapoint Street and Warner Avenue.

As water continued to spill onto the roadway even after the tide began to recede, PCH was ultimately shut down in both directions between Seal Beach and Huntington Beach.

Newport Beach was also bracing for the rising water, with officials activating pumps and building sand berms to protect vulnerable neighborhoods, particularly along the Balboa Peninsula.

The waterway beneath the Newport Boulevard Bridge was closed from 8:30 to 10:30 a.m. Tuesday to prevent boat wakes from sending more water into nearby properties during the morning high tide.

The tide reached a record-setting 8.4 feet at 10 a.m., forecasters said.

Boaters throughout Newport Harbor were urged to slow down and exercise caution near low-lying waterfront areas. The waterway beneath the bridge is scheduled to close again Wednesday from 9 to 11 a.m.

The flooding comes as tides along the Southland coast continue to approach historic levels.

A tide gauge in San Pedro reached 8.02 feet Monday, breaking the previous record of 7.93 feet set Jan. 10, 2005, according to the National Weather Service. Records at the gauge date back to November 1923.

Tides could remain near record levels through Wednesday, forecasters warned.

Newport Beach officials have also suspended parking enforcement through Wednesday evening to give residents time to move vehicles out of flood-prone areas.

A coastal flood warning remained in effect for the Orange County coastline through 1 p.m. Thursday, while a coastal flood advisory covered the Los Angeles County coastline through the same time.

Tides were running about 1 to 1.7 feet above astronomical predictions in Orange County and roughly 1 to 1.5 feet above predictions along the LA County coast.

More significant flooding and damage are possible in areas where little or no sandy beach remains, or where previous high tides have already caused problems, the NWS warned.

The rising water has also disrupted rail service. Metrolink’s Orange County Line was suspended Monday between Laguna Niguel/Mission Viejo and Oceanside, with trains originating and terminating at Laguna Niguel/Mission Viejo through Friday.

Away from the soggy coastline, Los Angeles and Orange counties can expect dry, mild weather through at least Friday, with temperatures gradually cooling and clouds increasing.

Rain could arrive this weekend, although forecasters say the potential storm system has been trending weaker in computer models.

“Still looks like a high chance of rain with the most likely period being Saturday into Sunday but at this time amounts seem to be under an inch,” according to the weather agency.

The chance of a brief shower Friday stands at 15% to 25%, with Saturday night offering the best chance of rain. Showers could taper off by Sunday afternoon, though confidence in the timing remains moderate.

Current projections call for roughly one-third to one-half inch of rain across most areas, with the eastern San Gabriel Mountains potentially receiving around an inch.