Overview -
Tropical Storm Hanna has the potential to bring heavy rain and tropical storm force winds to the local area from Friday night into Saturday night. Uncertainty remains with timing and track but chances are increasing that Hanna will have an impact on the local New York City area.
The remainder of the forecast is dependant on the strength and track of Hanna. At this time, the official forecast has Hanna making landfall early Saturday as a Category 1 hurricane along the Southeast coast (Carolinas) and then curving and racing to the North-Northeast as a tropical storm. The center of Hanna is forecasted to be near the Southern New Jersey coast by Saturday evening and then into Coastal New England on Sunday morning. Hanna is expected to remain offshore as she passes the region.
Precipitation -
Heavy tropical rainfall is expected throughout the area in association with this event. Light rainfall starts in NYC late Friday night, with a steadier rainfall continuing from 0200 hours on Saturday through 0200 hours on Sunday. The period of heaviest rainfall will occur during the morning, afternoon and early evening hours on Saturday.
Area rainfall totals of 3 to 4 inches are forecasted. Hourly rainfall rates between ¾ of an inch to 1-1/2 inches are possible during the passage of stronger bands of heavy rainfall. Dangerous flash flooding in addition to flooding of poor drainage and low-lying areas is expected.
Winds -
Winds will increase in intensity after Midnight on Saturday continuing g through the nighttime hours on Sunday. Sustained winds of 30 to 40 MPH with some higher gusts near 45 MPH are expected. Winds will be the strongest for communities along south-facing Atlantic Ocean shores.
Severe Weather -
Severe thunderstorms and even tornadoes are possible with landfalling tropical systems. The greatest threat for this activity will be to the east of the City based on Hanna's current forecast track, however, should the track of Hanna move to the west of the City, the chance of severe weather will increase.
Coastal Flooding, Storm Surge, Rip Currents & Beach Erosion -
Fortunately for New York City, we are currently in between astronomical high tide cycles. As such, coastal flooding impacts should be less severe. Tidal departures of 2 to 2-1/2 feet above normal are expected on Saturday with the storm surge produced by Tropical Storm Hanna. The strong onshore winds will result in some minor beach and coastal erosion. A moderate risk of rip currents exists today for the Atlantic Ocean beaches. This risk will increase to high as Hanna approaches the area on Friday and Saturday.
NWS Issued Products -
It is expected that the National Hurricane Center may will Tropical Storm Watches for the New York City area. These watches will most probably be issued with either the 0500 hours or 1100 hours forecast updates on Friday morning. These Tropical Storm Watches could be upgraded to Tropical Storm Warnings as Hanna approaches the area. Flooding related products may be issued as needed by the NWS.
Gary Hearn
Amtrak Station Action Team Coordinator
Penn Station, New York
