Tropical Storm Henri Discussion Number 27
NWS National Hurricane Center Miami FL AL082021
1100 AM EDT Sun Aug 22 2021
Henri's presentation in both satellite and radar imagery has
degraded significantly since the previous advisory due to the
cyclone having moved over much cooler water. An eyewall feature is
no longer evident and clouds tops have warmed markedly in the
inner-core region around the center. Data from an Air Force Reserve
reconnaissance aircraft, NOAA Doppler weather radars, and surface
observations indicate that Henri's peak winds have decreased to
50 kt despite the central pressure remaining constant at about 987
mb.
Henri is moving north-northwestward or 335/10 kt. The cyclone is
forecast to gradually turn northwestward later this afternoon and
possibly even move westward before stalling near the New
York-Connecticut border later tonight owing to interaction with a
mid- to upper-level low located over he DelMarVa region. The latter
system is expected to be absorbed by Henri by early Monday morning
before ejecting out slowly eastward to east-northeastward across
southern New England by Monday afternoon and evening. Henri is then
forecast to cross the southern Gulf of Maine and Nova Scotia as a
remnant low on Tuesday. The new NHC track forecast is a little to
the west and south of the previous advisory track, and lies close
to the tightly packed simple- and corrected-consensus track models.
Little change in strength is expected until Henri makes landfall in
the Rhode Island-eastern Connecticut area this afternoon. After
landfall, rapid weakening is forecast due to land interaction and
entrainment of cooler air coming in off of the Atlantic Ocean. Henri
should weaken to a tropical depression by early Monday, and become
post-tropical by Monday afternoon or evening.
Due to the degraded radar presentation of Henri, hourly Tropical
Cyclone Updates (TCU) will be discontinued after the 1100 AM EDT
advisory.
Key Messages:
1. Dangerous storm surge inundation is expected to continue today
in portions of Long Island, Connecticut, Rhode Island, and
southeastern Massachusetts, where a Storm Surge Warning has been
issued. Residents in these areas should follow any advice given by
local officials.
2. Tropical storm conditions will continue in portions of the
tropical storm warning area into tonight.
3. Heavy rainfall may lead to considerable flash, urban, and small
stream flooding, along with the potential for widespread minor to
isolated moderate river flooding over portions of Long Island, New
England, eastern New York, New Jersey and northeast Pennsylvania.
4. Swells from Henri will continue to affect much of the east coast
of the U.S. during the next day or so. These swells could cause
life-threatening surf and rip currents.
Tropical Storm Henri Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL082021
1230 PM EDT Sun Aug 22 2021
...TROPICAL STORM HENRI MAKES LANDFALL ALONG THE COAST OF RHODE
ISLAND NEAR WESTERLY...
Data from an Air Force Reserve reconnaissance aircraft, NOAA Doppler
weather radars, and surface observations indicate that the center of
Tropical Storm Henri made landfall along the coast of Rhode Island
near Westerly at approximately 1215 PM EDT this afternoon. At the
time of landfall, maximum sustained winds were estimated to be 60
mph.
A Weatherflow station near Point Judith, Rhode Island, recently
measured a sustained wind of 57 mph (92 km/h) and a gust to 70 mph
(113 km/h). The center of Henri passed over Block Island, Rhode
Island, around 1100 AM EDT...1500 UTC.
SUMMARY OF 1215 PM EDT...1615 UTC...INFORMATION
-----------------------------------------------
LOCATION...41.3N 71.8W
ABOUT 15 MI...25 KM NNE OF MONTAUK POINT NEW YORK
ABOUT 40 MI...65 KM SSW OF PROVIDENCE RHODE ISLAND
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...989 MB...29.20 INCHES
Tropical Storm Henri Discussion Number 19
NWS National Hurricane Center Miami FL AL082021
1100 AM EDT Fri Aug 20 2021
The Air Force Reserve Hurricane Hunters investigated Henri this
morning and based on the flight-level, SFMR, and dropsonde data, the
initial intensity is still around 55 kt. The minimum pressure has
also been relatively steady. The low-level center of Henri is
located close to the northwestern edge of the main area of deep
convection, and the vortex is still not vertically aligned due to
20-25 kt of northerly vertical wind shear. Although the intensity
of Henri has not changed much during the past couple of days,
satellite images show an improving cloud pattern with well-
established outflow in the eastern semicircle, which could indicate
that Henri is poised to strengthen.
There is some uncertainty in the exact position of Henri given the
recent aircraft fixes and the tilt of the vortex, but the initial
motion appears to be northwestward at 6 kt. A trough over the
central Appalachians is expected to cut off tonight, and the
combination of that feature and a building ridge to the
east/northeast of Henri should cause the storm to turn northward
tonight and accelerate in that direction on Saturday. Some of the
models show a slight bend to the west around the time Henri is
forecast to make landfall on Sunday, and there remains a fair amount
spread in the guidance in where the center of Henri will come
ashore. The latest GFS and ECMWF ensemble members span a region
from near New York City to Cape Cod for the landfall point. Based
on the latest consensus aids and initial position, the official
track forecast is nudged to the west of the previous one and shows
landfall occurring by late Sunday. After day 3, Henri is forecast
to eject northeastward across the Gulf of Maine.
The ongoing northerly shear is expected to decrease later today, and
the global models show a favorable upper-level wind pattern
developing over the storm later today through the weekend. These
more conducive atmospheric conditions combined with the warm Gulf
Stream waters should allow Henri to strengthen to a hurricane
tonight or early Saturday with additional intensification expected
into Saturday night. By early Sunday, however, Henri is forecast to
cross the north wall of the Gulf Stream, and that should end its
opportunity for strengthening. Although steady to rapid weakening is
forecast while Henri moves over cooler waters south of New England,
it will likely still be at or very near hurricane intensity when it
reaches the coast. Post-tropical transition is forecast to occur in
3 to 4 days, and the new forecast shows Henri dissipated by day 5,
in agreement with most of the global models.
Users are reminded to not focus on the exact forecast of the
center of Henri since impacts will extend far from the center.
Key Messages:
1. Dangerous storm surge inundation and hurricane conditions are
possible beginning Sunday in portions of Long Island, Connecticut,
Rhode Island, and southeastern Massachusetts, where a Storm Surge
Watch and Hurricane Watch are in effect. Residents in these areas
should follow any advice given by local officials.
2. Heavy rainfall may lead to flash, urban, and small stream
flooding, along with the potential for widespread minor and isolated
moderate river flooding, over portions of southern New England
Sunday into Monday.
3. Swells from Henri will begin to reach much of the east coast of
the U.S. and Atlantic Canada by the end of the week and continue
through the weekend. These swells could cause life-threatening surf
and rip currents.
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