Henri Downgraded To A Tropical Storm

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Highlight: Hurricane Warnings cancelled. Henri downgraded to a T.S.

Fig. 1: Weather satellite view of Tropical Storm Henri.

Fig. 2: Current NOAA/NHC forecast track for Tropical Storm Henri.

Fig. 3: GFS rainfall forecast associated with Tropical Storm Henri.

Fig. 4: NOAA/NHC storm surge forecast associated with Tropical Storm Henri.

Fig. 5-6: NOAA/NHC tropical storm/hurricane wind speed probability forecast.

Discussion: At 8AM EDT, Tropical Storm Henri was located at 40.7N/71.3W or about 40 miles south-southeast of Montauk Point, NY (Fig. 1). Henri is moving north-northwest at 16 mph with top wind 70 mph and central pressure 986 MB. Henri has moved north of the north wall of the Gulf Stream. Consequently, ocean waters are somewhat cooler and Henri has weakened slightly below hurricane intensity. Hurricane Warnings have been cancelled. The NOAA/NHC forecast track takes Henri north-northwestward to the Connecticut/Rhode Island early this afternoon as a strong tropical storm (Fig. 2). Henri may slow down once inland and continue to weaken to a tropical depression tonight. Later tomorrow Henri becomes a subtropical depression, turns eastward and exits the upper Maine Coast on Tuesday.

The rainfall forecast associated with Tropical Storm Henri utilizes the GFS model (Fig. 3). The heaviest rain (4-5 in.) is across western Massachusetts and northern Connecticut as Henri couples with an upper trough tonight/Monday. Similar amount occurs today across Long Island with 4-8 in. possible outer Long Island. Flash Flooding is widespread within the heavy rain area identified. East of the storm track heavy convective rains occur with hit-and-miss character. An isolated tornado or two is possible over southeastern New England today.

The NOAA/NHC storm surge potential forecast is likely correct for a few areas but most sections of Long Island Sound and south-coastal New England observe 1-3-foot storm surges (Fig. 4).

The tropical storm wind probability profile indicates most of southern New England experiences wind speeds in that category today mostly in the form of gusts well inland and on the east coast with sustained wind in this category most likely in Connecticut and Rhode Island (Fig. 5-6).