Philadelphia, PA 19112 Weather

What Has Changed

Updated Key Message 2 and wording to reflect recently developed Subtropical Storm Josephine.

Key Messages

1. Subtropical Storm Josephine located well off the Mid- Atlantic coast will move even farther away Thursday, however some coastal impacts and hazardous marine conditions continue.

2. Elevated tide cycles persist due to Subtropical Storm Josephine well of the coast with water levels peaking with this evening's high tide. Widespread minor coastal flooding is expected from Ocean County NJ southward through Delaware.

3. Frost impacts possible Friday night and Saturday night where the growing season continues.

Discussion

KEY MESSAGE 1...Subtropical Storm Josephine located well off the Mid- Atlantic coast will move even farther away Thursday, however some coastal impacts and hazardous marine conditions continue.

Subtropical Storm Josephine located well off the Mid-Atlantic coast will strengthen through tonight as it gradually turns more to the northeast. This northeast or east-northeast motion then continues on Thursday. Meanwhile, strong surface high pressure centered across New England will shift into the Canadian Maritimes tonight. A tightened pressure gradient remains between these two systems through tonight.

Some impacts remain only for our coastal and marine areas. The multi- day north-northeast wind has resulted in 10+ foot waves just offshore. These big waves breaking onto the beaches will result in some additional beach erosion especially during times of high tide. Peak wind gusts in the 30-40 mph range into this evening for areas along the coast, and 20-30 mph inland. The winds will diminish late this afternoon and especially tonight particularly away from the immediate coast. Some mid to mostly high clouds into tonight will occur especially closer to the coast. As the winds diminish tonight, it will be a chilly night, however frost is not expected.

For Thursday into Friday, Subtropical Storm Josephine will move farther out to sea as an incoming system from the northwest kicks it out. This will reduce the marine and coastal impacts, while keeping our weather dry and providing a fresh shot of chilly air. There will still be a notable north-northwest breeze Thursday as the pressure gradient remains tightened due to another incoming strong surface high from Canada.

KEY MESSAGE 2...Elevated tide cycles persist due to Subtropical Storm Josephine well of the coast with water levels peaking with this evening's high tide. Widespread minor coastal flooding is expected from Ocean County NJ southward through Delaware.

As Subtropical Storm Josephine lingers well off the coast elevated tide cycles persist with water levels peaking this evening. Expect fairly widespread but minor flooding from Ocean County NJ southward through Delaware including the Delaware shores of Delaware Bay. In some of the back bays, moderate coastal flooding is still possible this evening however the chances for this have lowered some as recent tide cycles have generally not been quite as high as forecast. Beyond this evening, Josephine will gradually be moving to the northeast away from the region for the end of the week. Another round of minor coastal flooding is possible Thursday evening though at this time it's looking to be more spotty in nature.

Aviation

The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Rest of this afternoon...VFR with some high clouds. North-northeast winds 10-15 knots with gusts 20-25 knots at times. Moderate confidence.

Tonight...VFR. North-northeast winds diminishing to 10 knots or less, then becoming north-northwest (becoming locally light and variable). Moderate confidence.

Thursday...VFR. North to northwest winds increasing to 10-15 knots with some gusts to around 20 knots. Moderate confidence.

Outlook...

Thursday night...VFR. North-northwest winds diminishing to 10 knots or less.