Alabama 811 | Know What's Below.

7 pm Advisory — Henri Turns Northward; Expected to Become a Hurricane Soon

| August 20, 2021 @ 8:55 pm

SUMMARY OF 7 PM CDT INFORMATION
LOCATION…31.6N 73.8W
ABOUT 270 MI…435 KM SSE OF CAPE HATTERAS NORTH CAROLINA
ABOUT 660 MI…1060 KM S OF MONTAUK POINT NEW YORK
MAXIMUM SUSTAINED WINDS…70 MPH…110 KM/H
PRESENT MOVEMENT…N OR 360 DEGREES AT 7 MPH…11 KM/H
MINIMUM CENTRAL PRESSURE…994 MB…29.36 INCHES

WATCHES AND WARNINGS
A Storm Surge Warning is in effect for…
* South shore of Long Island from Mastic Beach to Montauk Point
* North shore of Long Island from Oyster Bay to Montauk Point
* Greenwich Connecticut to Chatham Massachusetts
* Nantucket, Martha’s Vineyard, and Block Island

A Storm Surge Watch is in effect for…
* South shore of Long Island from west of Mastic Beach to East Rockaway Inlet
* North shore of Long Island from west of Oyster Bay to Flushing
* Flushing New York to west of Greenwich Connecticut
* North of Chatham Massachusetts to Sagamore Beach Massachusetts
* Cape Cod Bay

A Hurricane Warning is in effect for…
* South shore of Long Island from Fire Island Inlet to Montauk Point
* North shore of Long Island from Port Jefferson Harbor to Montauk Point
* New Haven Connecticut to west of Watch Hill Rhode Island

A Hurricane Watch is in effect for…
* Watch Hill Rhode Island to Sagamore Beach Massachusetts
* Nantucket, Martha’s Vineyard, and Block Island

A Tropical Storm Warning is in effect for…
* Port Jefferson Harbor to west of New Haven Connecticut
* South shore of Long Island from west of Fire Island Inlet to East Rockaway Inlet

A Tropical Storm Watch is in effect for…
* Manasquan Inlet New Jersey to west of East Rockaway Inlet New York, including New York City

FORECAST DISCUSSION
At 800 PM EDT (0000 UTC), the center of Tropical Storm Henri was located near latitude 31.6 North, longitude 73.8 West. Henri is now moving toward the north near 7 mph (11 km/h). A continued forward motion at a faster forward speed is expected through early Sunday. On the forecast track, Henri is expected to make landfall in Long Island or southern New England on Sunday.

Reports from NOAA and Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds are near 70 mph (110 km/h) with higher gusts. Strengthening is forecast during the next day or so, and Henri is expected to become a hurricane tonight or Saturday and be at or near hurricane strength when it makes landfall in Long Island or southern New England.

Tropical-storm-force winds extend outward up to 115 miles (185 km) from the center.

The minimum central pressure estimated from the Hurricane Hunter aircraft data is 994 mb (29.36 inches).

HAZARDS TO LAND
STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide…

• Watch Hill, RI to Chatham, MA including Narragansett Bay, Buzzards Bay, Vineyard Sound, and Nantucket Sound…3-5 ft
• Chatham, MA to Sagamore Beach, MA including Cape Cod Bay…2-4 ft
• East Rockaway Inlet, NY to Montauk Point, NY…2-4 ft
• North shore of Long Island…2-4 ft
• Flushing, NY to Watch Hill, RI…2-4 ft
• Cape May, NJ to East Rockaway Inlet, NY…1-3 ft

The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and dangerous waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office.

WIND: Hurricane conditions are expected in the hurricane warning area on Sunday, with tropical storm conditions expected by early Sunday. Hurricane conditions are possible in the hurricane watch area on Sunday, with tropical conditions possible by early Sunday. Tropical storm conditions are expected in the tropical storm warning area and possible in the tropical storm watch area on Sunday.

RAINFALL: Henri may produce rainfall amounts of 3 to 6 inches over Long Island and New England Sunday into Monday, with isolated maximum totals near 10 inches. Heavy rainfall from Henri could result in considerable flash, urban, and small stream flooding, along with the potential for widespread minor and isolated moderate river flooding.

SURF: Swells generated by Henri should continue to affect Bermuda during the next day or so. Swells are expected to increase across much of the east coast of the U.S. and Atlantic Canada tonight and into the weekend. These swells could cause life-threatening surf and rip current conditions. Please consult products from your local weather office.

Category: ALL POSTS, Severe Weather, Tropical

About the Author ()

Scott Martin is an operational meteorologist, professional graphic artist, musician, husband, and father. Not only is Scott a member of the National Weather Association, but he is also the Central Alabama Chapter of the NWA president. Scott is also the co-founder of Racecast Weather, which provides forecasts for many racing series across the USA. He also supplies forecasts for the BassMaster Elite Series events including the BassMaster Classic.

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