A storm system moving into the northeast from the Ohio Valley will set the stage for not only wind and rain, but also for a moderate coastal flooding event which is expected to unfold around Philadelphia and the Delaware River, Delaware and Maryland beaches, and the Jersey Shore. Because of this coastal flood threat, the National Weather Service has issued Coastal Flood Watches and Coastal Flood Advisories for portions of the Mid Atlantic Coast.

Low pressure near the Ohio Valley will continue to strengthen while moving north through the day. The front that has been across the area yesterday and last night will get caught in the increasing southerly flow on the east side of the low and move north in response. Winds will increase this afternoon, with south to southeast winds up to 15-20 mph and some gusts up to 30 mph possible late.

Tonight, the low pressure system will continue to deepen while it moves from near Lake Erie into southern Canada. A front attached to the low will be in the  Mid Atlantic by daybreak Friday. As this happens, showers and thunderstorms are expected, along with gusty winds   sustained 20 to 25 mph and gusts 35 to 40 mph at times.

These strong gusty winds will help push water into coastal areas of the Mid Atlantic, creating coastal flood concerns. Water levels have remained elevated over the last week with flood levels ranging from spotty minor to widespread minor. This will continue through tonight and tomorrow morning’s high tide, with some locations getting to moderate, possibly even major, flood levels.

Coastal Flood Warnings are in effect for the coastal areas along the northern Delaware Bay and the tidal Delaware River. Computer forecast guidance used by the National Weather Service strongly points to moderate flooding over this region with some guidance suggesting near-major flooding possible at Burlington in New Jersey .

According to the National Weather Service, the Chesapeake Bay is a bit of an outlier and their confidence in flooding conditions there remains low. As a result, that area is under a Coastal Flood Watch for now. However,  Tolchester is near moderate flood status while Claiborne remains at minor flood status.

For the rest of the Atlantic coastline, the National Weather Service issued a Coastal Flood Advisory for tonight for all sites from Sandy Hook on south. Sandy Hook and Manasquan are currently forecast to get right to advisory-minor, but guidance at some of the back bay sites has widespread minor flooding occurring.  Only spotty minor tidal flooding is expected at Perth Amboy at this time; because of that, no advisory is in effect there.