老農民版夜神月

  一級颶風  
編號：08 L
名稱：Henri

  基本資料  
擾動編號日期：2021 年 08 月 15 日 07 時
命名日期　　：2021 年 08 月 17 日 05 時
撤編日期　　：2021 年 08 月 25 日 02 時
登陸地點　　：美國 羅德島州

  巔峰時期資料  
近中心最強風速 ：65  kt ( Cat.1 )
海平面最低氣壓 ：991 百帕

  擾動編號資料  
96L.INVEST.15kts.1013mb.37N.65W

NHC：20%

1. A small area of low pressure associated with disorganized showers
and thunderstorms has developed more than 200 miles north-northeast
of Bermuda. Some gradual development is possible over this weekend
into early next week as this system drifts slowly southward near
Bermuda over the next few days.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...30 percent.

以上資料來自：NHC、颱風論壇整理製作

老農民版夜神月

已成為後熱帶氣旋,由於仍症影響美國陸地,WPC持續對其發報

000
WTNT33 KWNH 232052
TCPAT3

BULLETIN
Post-Tropical Cyclone Henri Advisory Number  32
NWS Weather Prediction Center College Park MD   AL082021
500 PM EDT Mon Aug 23 2021

...HENRI IS NOW A POST-TROPICAL CYCLONE AND SLOWLY MOVING EAST...
...HEAVY RAINFALL AND FLOODING EXPECTED TO CONTINUE ACROSS PORTIONS
OF SOUTHERN NEW ENGLAND THROUGH TONIGHT...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...41.6N 73.6W
ABOUT 60 MI...95 KM NNE OF NEW YORK CITY
ABOUT 50 MI...80 KM WSW OF HARTFORD CONNECTICUT
MAXIMUM SUSTAINED WINDS...25 MPH...35 KM/H
PRESENT MOVEMENT...ENE OR 75 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


WATCHES AND WARNINGS
--------------------
Flood watches are in effect across portions of southeast New York
and southern New England.


DISCUSSION AND OUTLOOK
----------------------
At 500 PM EDT (2100 UTC), the center of Post-Tropical Cyclone Henri
was located near latitude 41.6 North, longitude 73.6 West. The
post-tropical cyclone is moving toward the east-northeast near 9 mph
(15 km/h) and this motion is expected to accelerate later tonight.

Maximum sustained winds are near 25 mph (35 km/h) with higher gusts.
Little change in strength is forecast during the next 24 hours.

The estimated minimum central pressure is 1005 mb (29.68 inches).


HAZARDS AFFECTING LAND
----------------------

RAINFALL: Remnant moisture from Henri is expected to produce
additional rainfall of 1 to locally 2 inches in New Jersey, eastern
Pennsylvania, and southern New York through this evening and 1 to 3
inches, with locally higher amounts possible, over southern to
central New England through tonight. Heavy rainfall from Henri will
continue to result in limited flash, urban, and small stream
flooding impacts, along with isolated minor to moderate river
flooding.

The flood risk associated with Henri is expected to diminish by
early Tuesday.

For the latest rainfall reports and wind gusts associated with Henri
at the following link:
https://www.wpc.ncep.noaa.gov/discussions/nfdscc3.html

TORNADOES: A brief tornado or two is possible across Southern
New England through this evening.

SURF: Swells are expected to continue across much of the east
coast of the U.S. and Atlantic Canada through tonight. These swells
could cause life-threatening surf and rip current conditions.
Please consult products from your local weather office.

NEXT ADVISORY
-------------
Next complete advisory at 1100 PM EDT.

$$
Forecaster Churchill/Pagano

FORECAST POSITIONS AND MAX WINDS

INIT  23/2100Z 41.6N  73.6W   20 KT  25 MPH...POST-TROP/INLAND
12H  24/0600Z 41.7N  71.9W   20 KT  25 MPH...POST-TROP/INLAND
24H  24/1800Z 42.4N  68.2W   25 KT  30 MPH...POST-TROPICAL
36H  25/0600Z...DISSIPATED

老農民版夜神月

NHC降格TD

08L HENRI 210823 0000 41.8N 72.9W ATL 30 1000

822
WTNT33 KNHC 222346
TCPAT3

BULLETIN
Tropical Depression Henri Intermediate Advisory Number 28A
NWS National Hurricane Center Miami FL       AL082021
800 PM EDT Sun Aug 22 2021

...HENRI WEAKENING BUT STILL EXPECTED TO PRODUCE HEAVY
RAINFALL AND FLOODING ACROSS PORTIONS OF SOUTHERN NEW ENGLAND AND
THE NORTHERN MID-ATLANTIC STATES THROUGH MONDAY...


SUMMARY OF 800 PM EDT...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...41.7N 72.8W
ABOUT 10 MI...15 KM SW OF HARTFORD CONNECTICUT
ABOUT 90 MI...140 KM NE OF NEW YORK CITY
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES

老農民版夜神月

登陸時部分雲圖,底層掃描,風場掃描

t02436

15Z評價50節，強對流皆已上陸。
根據最新實測資料，中心已在近岸，一小時內就會正式登陸，登陸點在羅德島州(RI)與康乃狄克州(CT)交界。

000
WTNT43 KNHC 221501
TCDAT3

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.

FORECAST POSITIONS AND MAX WINDS

INIT  22/1500Z 41.1N  71.6W   50 KT  60 MPH
12H  23/0000Z 42.4N  73.2W   35 KT  40 MPH...INLAND
24H  23/1200Z 43.0N  72.7W   30 KT  35 MPH...INLAND
36H  24/0000Z 43.3N  71.3W   25 KT  30 MPH...POST-TROP/INLAND
48H  24/1200Z 43.7N  68.7W   25 KT  30 MPH...POST-TROP/INLAND
60H  25/0000Z 44.3N  64.5W   25 KT  30 MPH...POST-TROPICAL
72H  25/1200Z...DISSIPATED

$$
Forecaster Stewart

中心已於1615Z登陸羅州，登陸強度為50Kts、989hPa。

000
WTNT63 KNHC 221628
TCUAT3

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

$$
Forecaster Stewart/Brennan

老農民版夜神月

NHC升格C1

263
WTNT43 KNHC 211442
TCDAT3

Hurricane Henri Discussion Number  23
NWS National Hurricane Center Miami FL       AL082021
1100 AM EDT Sat Aug 21 2021

The Air Force Reserve and NOAA Hurricane Hunters have been
investigating Henri this morning and continue to provide very
valuable data.  The Air Force aircraft measured a peak flight-level
wind of 82 kt at 700 mb, which easily supports hurricane strength,
but the initial intensity is set at 65 kt as a blend of these data
and somewhat lower SFMR winds.  In addition, aircraft data indicate
that the minimum pressure has fallen to 991 mb.  The NOAA tail
Doppler radar data indicate that the storm is becoming more
vertically aligned and that a more symmetric eyewall appears to be
forming.  In addition, dropsonde data from the NOAA Gulfstream IV
aircraft flying around Henri indicate that the 34- and 50-kt wind
radii are a little larger than previously estimated in the
southeastern quadrant.  NOAA buoy 41001 located in the northeastern
quadrant of the hurricane has recently reported 18 ft. seas.

Henri is moving north-northeastward, or 020 degrees, at 12 kt.  The
steering pattern appears fairly well established now with a cut off
low located over the central Appalachians and a ridge building to
the east and northeast of Henri.  This pattern should cause the
storm to accelerate to the north or north-northeast today followed
by a slight bend to the left on Sunday.  The latest run of the GFS
has shifted to the east, but overall the models are focused in on
landfall being between central Long Island and Rhode Island on
Sunday.  However, users are reminded to not focus on the center
itself, as impacts will extend well away from the center, especially
to the east.  The new NHC track forecast is a little to the east of
the previous one and very near the best-performing models, the
consensus aids.

The environment looks favorable for Henri to continue to gain
strength through tonight with low shear, upper-level divergence
associated with the upper-level trough, and warm SSTs.  In fact,
the GFS and HWRF models show the minimum pressure dropping by 15 mb
or more during that time period.  By early Sunday, Henri is
predicted to cross the north wall of the Gulf Stream and that should
cause some weakening, but Henri is forecast to be at or near
hurricane strength at landfall. Once the center moves inland over
the northeast United States, rapid weakening is expected.  Henri is
forecast to become post-tropical in 48-60 hours and dissipate in 3
to 4 days.

Key Messages:

1. Dangerous storm surge inundation is expected to begin late
tonight or Sunday in portions of Long Island, Connecticut,
Rhode Island, and southeastern Massachusetts, where a Storm Surge
Warning has been issued. Dangerous storm surge is possible
beginning late tonight or Sunday in western portions of Long
Island and Connecticut in the Storm Surge Watch area.  Residents in
these areas should follow any advice given by local officials.

2. Hurricane conditions are expected to begin late tonight or
Sunday in portions of Long Island, Connecticut, and Rhode Island,
where a Hurricane Warning is in effect. Tropical storm conditions
will begin in these areas tonight.

3. Heavy rainfall may lead to considerable flash, urban, and small
stream flooding, along with the potential for widespread minor and
isolated moderate river flooding, over portions of Long Island, New
England, southeast New York and northern New Jersey.

4. Swells from Henri will continue to affect much of the east coast
of the U.S. during the next day or two. These swells could cause
life-threatening surf and rip currents.

FORECAST POSITIONS AND MAX WINDS

INIT  21/1500Z 34.4N  72.5W   65 KT  75 MPH
12H  22/0000Z 36.9N  71.9W   75 KT  85 MPH
24H  22/1200Z 39.7N  71.9W   70 KT  80 MPH
36H  23/0000Z 41.3N  72.6W   60 KT  70 MPH...INLAND
48H  23/1200Z 42.4N  72.9W   35 KT  40 MPH...INLAND
60H  24/0000Z 43.1N  71.9W   25 KT  30 MPH...POST-TROP/INLAND
72H  24/1200Z 43.8N  69.2W   25 KT  30 MPH...POST-TROP/INLAND
96H  25/1200Z...DISSIPATED

$$
Forecaster Cangialosi

老農民版夜神月

NHC新報定強來到TS上限60節,可能即將升格C1
並預測+24H後便將達到顛峰70節

599
WTNT43 KNHC 202042
TCDAT3

Tropical Storm Henri Discussion Number  20
NWS National Hurricane Center Miami FL       AL082021
500 PM EDT Fri Aug 20 2021

Henri appears to be slowly gaining strength.  Deep convection has
been increasing during the past few hours and the upper-level
outflow continues to become better established on the east side of
the circulation.  However, the low-level center is still located
near the northwestern edge of the deep convection due to ongoing
northerly wind shear.  An ASCAT-B pass from a few hours ago showed
peak winds of around 55 kt, with the strongest winds on the
southeast side of the circulation. Based on this data, the initial
intensity is set at 60 kt.  An Air Force Reserve Hurricane Hunter
aircraft is scheduled to investigate Henri again this evening and
the data the plane collects will be very helpful in estimating the
storm's strength and structure.

The tropical storm appears to be making the advertised turn to the
right, with the latest initial motion estimated to be 335/6 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 accelerate to the
north on Saturday.  The latest model runs have generally trended to
the left again and are a bit faster, with most showing landfall in
about 48 hours.  Most of the models now show a slight left turn
before landfall as Henri gets caught in the circulation of the
aforementioned trough.  The latest GFS and ECMWF ensemble members
continue to span a region from near New York City to Cape Cod for
the landfall point.  Based on the latest consensus aids, the
official track forecast has again been nudged to the west of the
previous one and shows landfall occurring on Sunday.  After day 3,
Henri is forecast to eject northeastward.

The ongoing northerly shear is expected to decrease tonight, and
the global models show a favorable upper-level wind pattern
developing over the storm 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 Long
Island and 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 by day 3 and the system should
dissipate in 4 or 5 days.

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 is expected to begin Sunday in
portions of Long Island, Connecticut, Rhode Island, and
southeastern Massachusetts, where a Storm Surge Warning has been
issued. Dangerous storm surge is possible beginning Sunday in
western portions of Long Island and Connecticut in the Storm Surge
Watch area.  Residents in these areas should follow any advice given
by local officials.

2. Hurricane conditions are expected to begin Sunday in portions
of Long Island and Connecticut, where a Hurricane Warning has been
issued.  Hurricane conditions are possible Sunday across portions
of Rhode Island and southeastern Massachusetts.

3. Heavy rainfall may lead to considerable flash, urban, and small
stream flooding, along with the potential for widespread minor and
isolated moderate river flooding, over portions of Long Island and
New England Sunday into Monday.

4. Swells from Henri will continue to affect much of the east coast
of the U.S. through the weekend. These swells could cause
life-threatening surf and rip currents.

FORECAST POSITIONS AND MAX WINDS

INIT  20/2100Z 31.2N  73.9W   60 KT  70 MPH
12H  21/0600Z 32.8N  73.3W   65 KT  75 MPH
24H  21/1800Z 35.8N  72.3W   75 KT  85 MPH
36H  22/0600Z 38.9N  71.9W   75 KT  85 MPH
48H  22/1800Z 40.8N  72.4W   65 KT  75 MPH
60H  23/0600Z 42.0N  72.8W   45 KT  50 MPH...INLAND
72H  23/1800Z 42.9N  72.6W   30 KT  35 MPH...POST-TROPICAL
96H  24/1800Z 43.8N  68.9W   25 KT  30 MPH...POST-TROPICAL
120H  25/1800Z...DISSIPATED

$$
Forecaster Cangialosi

t02436

開始轉向北上，預測+60將以TS上限強度登陸康乃狄克州，直接侵襲波士頓等東北部城市

455
WTNT43 KNHC 201445
TCDAT3

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.

FORECAST POSITIONS AND MAX WINDS

INIT  20/1500Z 30.4N  73.7W   55 KT  65 MPH
12H  21/0000Z 31.5N  73.7W   60 KT  70 MPH
24H  21/1200Z 34.1N  72.7W   70 KT  80 MPH
36H  22/0000Z 37.3N  71.8W   75 KT  85 MPH
48H  22/1200Z 39.8N  71.7W   65 KT  75 MPH
60H  23/0000Z 41.4N  71.8W   60 KT  70 MPH...INLAND
72H  23/1200Z 42.4N  71.8W   40 KT  45 MPH...INLAND
96H  24/1200Z 43.7N  69.4W   35 KT  40 MPH...POST-TROPICAL
120H  25/1200Z...DISSIPATED

$$
Forecaster Cangialosi