老農民版夜神月

NHC將其暫時降格為TD,並預估直到穿越古巴後才回重新增強為TS

000
WTNT42 KNHC 152051
TCDAT2

Tropical Depression Grace Discussion Number  10
NWS National Hurricane Center Miami FL       AL072021
500 PM AST Sun Aug 15 2021

An earlier ASCAT pass over Grace suggested that the maximum winds
were 25-30 kt and this has been confirmed by observations from a
NOAA Hurricane Hunter aircraft.  Aircraft and scatterometer data
also suggest that the circulation is elongated and disorganized.
Based on these data, the system is being downgraded to a 30-kt
depression at this time.  Since the system is below storm strength
and is passing by Puerto Rico, the Tropical Storm Warnings for
Puerto Rico and the U.S. Virgin Islands have been discontinued.  The
island of Hispaniola is kept under a Tropical Storm Watch given the
possibility that the system could restrengthen tonight or tomorrow
morning before moving over land. Most of the reliable guidance
shows little change in strength over the next 2-3 days.  This seems
reasonable since the circulation will be interacting with the
mountainous land mass of Hispaniola and Cuba for the next 72 hours.  
The official intensity forecast is near or a little above the DSHIPS
and LGEM guidance during that time.  Some restrengthening is
possible later in the forecast period when the system is expected to
move over the Gulf of Mexico. However, the global models are not
very bullish on intensification in 4-5 days, perhaps due to drier
air.

The system has moved mainly westward today, but the track models
are generally in agreement on a west-northwestward motion over the
forecast period.  This is consistent with a well-defined mid-level
ridge staying in place over the southwestern Atlantic and across
Florida during this week.  The official track forecast has been
shifted a little south of the previous one, following the
multi-model consensus.  

Key Messages:

1. Heavy rainfall could lead to flash and urban flooding over the
Virgin Islands.  Across Puerto Rico, the Dominican Republic and
Haiti, heavy rainfall may lead to flash, urban and small stream
flooding, along with the potential for mudslides.

2. Tropical storm conditions are possible over portions of
Hispaniola Monday and Monday night.

3. There is a risk of some wind and rainfall impacts across the
Turks and Caicos Islands, the Bahamas, Cuba, and Florida, but
forecast uncertainty is much higher than usual. Interests in those
areas should monitor the progress of Grace and updates to the
forecast.

FORECAST POSITIONS AND MAX WINDS

INIT  15/2100Z 17.0N  67.3W   30 KT  35 MPH
12H  16/0600Z 17.6N  68.8W   30 KT  35 MPH
24H  16/1800Z 18.2N  71.0W   30 KT  35 MPH...INLAND
36H  17/0600Z 19.2N  73.2W   30 KT  35 MPH...OVER WATER
48H  17/1800Z 20.2N  75.8W   30 KT  35 MPH...INLAND
60H  18/0600Z 21.0N  78.7W   30 KT  35 MPH...OVER WATER
72H  18/1800Z 22.1N  81.8W   30 KT  35 MPH
96H  19/1800Z 24.0N  87.0W   35 KT  40 MPH
120H  20/1800Z 25.0N  91.0W   45 KT  50 MPH

$$
Forecaster Pasch

老農民版夜神月

NHC新報較為看好後期發展,預測有望於登陸墨西哥前至少達到C1強度

ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM

Tropical Depression Grace Discussion Number  14
NWS National Hurricane Center Miami FL       AL072021
500 PM EDT Mon Aug 16 2021

Grace may have regained tropical storm status just before the
center moved across the Barahona Peninsula of the Dominican
Republic around midday.  The Air Force Reserve Hurricane Hunters
measured peak 925-mb winds of 45 kt very near the coast, which
would equate to an intensity right at the threshold of tropical
storm.  Since then, however, land interaction has likely weakened
these winds, and Grace is still estimated to be a 30-kt depression.
The center appears to have moved back over water just to the south
of the Haitian coast.

Grace has been moving a little slower today, possibly due to
interaction with the terrain of Hispaniola, and the initial motion
is estimated to be 285/11 kt.  A mid-level high centered over the
western Atlantic is forecast to build westward over the
southeastern United States and northern Gulf of Mexico in the
coming days.  This pattern should keep Grace on a westward to
west-northwestward trajectory for the entire 5-day forecast period,
moving across the northwestern Caribbean Sea, across the northern
Yucatan Peninsula, and into the southwestern Gulf of Mexico.  The
most significant model trends are on days 4 and 5, when many of the
track models are indicating a slight west-southwest bend as the
cyclone approaches mainland Mexico.  The NHC track forecast has
been nudged southward at most forecast times, but that may be
within the noise level of typical model run-to-run variability.

Once the center of Grace moves away from Hispaniola tomorrow, the
deep, warm waters of the northwestern Caribbean Sea and relatively
light deep-layer shear should be conducive for strengthening.
Model data suggest that some mid-level shear could come into play
at times, so it's not a sure bet that conditions will be ideal for
significant strengthening.  Partly for that reason, the NHC
intensity forecast is near or just below the intensity consensus.
However, even this new forecast is a little higher than the
previous forecast, and many of the models indicate that Grace could
be near or at hurricane strength when it approaches the Yucatan
Peninsula in about 60 hours.  After passing the Yucatan Peninsula,
additional strengthening is likely, and the new forecast now
explicitly shows Grace reaching hurricane intensity over the
southwestern Gulf of Mexico.


Key Messages:

1. Heavy rainfall across the Dominican Republic, Haiti, Cuba,
Jamaica, and the Cayman Islands may lead to flash, urban, and small
stream flooding, with the potential for mudslides highest in Haiti
and the Dominican Republic.

2. Tropical storm conditions are possible over portions of
Hispaniola this evening and tonight, and over Jamaica on Tuesday.
Tropical storm conditions are expected over portions of the southern
coast of Cuba on Tuesday, spreading westward to the Cayman Islands
and possibly other portions of the southern coast of Cuba Tuesday
evening through Wednesday morning.

3.  There is a increasing risk of wind, rainfall, and storm surge
impacts on the Yucatan Peninsula of Mexico Wednesday night and
Thursday.  Interests there areas should monitor the progress of
Grace and updates to the forecast.


FORECAST POSITIONS AND MAX WINDS

INIT  16/2100Z 17.9N  72.4W   30 KT  35 MPH
12H  17/0600Z 18.3N  74.4W   30 KT  35 MPH...NEAR SW TIP OF HAITI
24H  17/1800Z 18.9N  77.2W   35 KT  40 MPH
36H  18/0600Z 19.6N  80.4W   40 KT  45 MPH...NEAR CAYMAN ISLANDS
48H  18/1800Z 20.2N  83.5W   50 KT  60 MPH
60H  19/0600Z 20.9N  86.7W   60 KT  70 MPH...NEAR YUCATAN COAST
72H  19/1800Z 21.6N  89.9W   60 KT  70 MPH
96H  20/1800Z 22.4N  95.1W   65 KT  75 MPH
120H  21/1800Z 22.4N  98.8W   65 KT  75 MPH...INLAND

$$
Forecaster Berg

NNNN

老農民版夜神月

現正通過牙買加,NHC新報上修預測巔峰來到75節

272
WTNT42 KNHC 172056
TCDAT2

Tropical Storm Grace Discussion Number  18
NWS National Hurricane Center Miami FL       AL072021
500 PM EDT Tue Aug 17 2021

Radar imagery and earlier Hurricane Hunter aircraft and ASCAT
observations indicate that the center of Grace has been moving over
Jamaica.  The aircraft and scatterometer data indicate that the
maximum winds are near 45 kt.  Cirrus-level outflow from the
system remains quite pronounced, suggestive of weak vertical shear
at this time.

Grace will be moving over the waters of the northwestern Caribbean
Sea beginning later tonight.  These waters are of very high oceanic
heat content.  Although mid-level environmental humidities are
shown by the SHIPS diagnoses to be only marginally moist for the
next couple of days, other factors should be conducive for
strengthening.  The official intensity forecast, which shows Grace
becoming a hurricane tomorrow, is in reasonable agreement with the
latest multi-model consensus.  Some slight weakening should occur
due to passage over the Yucatan Peninsula, followed by
re-intensification over the Bay of Campeche.  There is, however,
significant uncertainty in the intensity prediction for this latter
part of the forecast period.

The storm continues on a heading just north of west, or 280/13 kt.  
A strong 500-mb ridge should be maintained to the north of Grace
for essentially the entire forecast period.  There is good
agreement among the track models on a continued generally westward
to west-northwestward motion for the next 5 days.  Little change
has been made to the official track forecast in comparison to the
previous one.  The new NHC track is, again, very close to the
dynamical model consensus.


Key Messages:

1.  Hurricane conditions and a dangerous storm surge are expected
over portions of the Hurricane Warning area in the eastern Yucatan
Peninsula of Mexico late Wednesday night.

2. Heavy rainfall across Haiti, Cuba, Jamaica, the Cayman Islands,
and the Yucatan Peninsula is likely to cause to flash, urban, and
small stream flooding, with the potential for mudslides highest in
Haiti.

3. Tropical storm conditions are expected over portions of Jamaica
through this evening, and over the Cayman Islands tonight and
early Wednesday.  Tropical storm conditions are expected to spread
westward from portions of the southern coast of Cuba in the warning
area to, possibly, other portions of the southern coast of Cuba in
the watch area tonight through Wednesday.


FORECAST POSITIONS AND MAX WINDS

INIT  17/2100Z 18.4N  77.9W   45 KT  50 MPH
12H  18/0600Z 18.9N  80.3W   60 KT  70 MPH
24H  18/1800Z 19.4N  83.4W   70 KT  80 MPH
36H  19/0600Z 20.0N  86.7W   75 KT  85 MPH
48H  19/1800Z 20.5N  89.7W   60 KT  70 MPH...INLAND
60H  20/0600Z 20.9N  92.2W   65 KT  75 MPH...OVER WATER
72H  20/1800Z 21.2N  94.8W   75 KT  85 MPH
96H  21/1800Z 21.0N  99.5W   40 KT  45 MPH...INLAND
120H  22/1800Z 21.0N 103.0W   20 KT  25 MPH...POST-TROP/INLAND

$$
Forecaster Pasch

t02436

15Z評價65節，達一級颶風強度，將在24小時內以巔峰登陸墨西哥猶加敦半島。

000
WTNT42 KNHC 181500
TCDAT2

Hurricane Grace Discussion Number  21
NWS National Hurricane Center Miami FL       AL072021
1100 AM EDT Wed Aug 18 2021

Grace is becoming better organized on satellite images with a
comma-shaped cloud pattern, and the upper-level outflow remains
well defined.  Wind gusts well into the hurricane-force range were
measured on Grand Cayman earlier this morning, along with some
damage on the island.  Recent flight-level and SFMR observations
from both the Air Force and NOAA Hurricane Hunter aircraft support
sustained 65-kt surface winds, so the system is being upgraded to a
hurricane on this advisory.

Although Grace is situated over waters of very high oceanic heat
content, moderate northwesterly shear and only marginally moist
mid-level air could slightly impede intensification.  However,
some additional strengthening is expected before landfall tonight
or early Thursday.  Weakening will occur due to Grace's passage
over Yucatan, although that land mass has relatively low terrain.  
Reintensification is anticipated over the Bay of Campeche on
Friday, and the system should regain hurricane strength before
reaching the east coast of mainland Mexico.  The official intensity
forecast is similar to the numerical model consensus.

Grace has been moving west-northwestward near 13 kt.  A prominent
mid-tropospheric ridge is likely to remain in place to the north of
the cyclone for the next several days.  This pattern should keep
steering Grace on a west-northwestward to westward track for 72-96
hours.  The track guidance models are in excellent agreement and
little change has been made to the NHC track forecast compared to
the previous few packages.

A Hurricane Watch will likely be required for a portion of the
coast of eastern mainland Mexico later today.

Key Messages:

1. Hurricane conditions and a dangerous storm surge are expected
in portions of the Hurricane Warning area in the eastern Yucatan
Peninsula of Mexico beginning late tonight or early Thursday.
Preparations to protect life and property should be rushed to
completion.

2. There is an increasing risk of hurricane conditions and dangerous
storm surge in portions of eastern mainland Mexico beginning late
Friday, and a Hurricane Watch will likely be issued for part of this
area later today.

3. Over the next few days, heavy rainfall across the Cayman Islands
as well as portions of the Yucatan Peninsula and Veracruz State
should lead to flash and urban flooding, with mudslides possible in
the Mexican state of Veracruz.  

FORECAST POSITIONS AND MAX WINDS

INIT  18/1500Z 19.4N  82.2W   65 KT  75 MPH
12H  19/0000Z 19.7N  84.5W   70 KT  80 MPH
24H  19/1200Z 20.3N  87.6W   75 KT  85 MPH...INLAND
36H  20/0000Z 20.6N  90.5W   50 KT  60 MPH...OVER WATER
48H  20/1200Z 20.7N  93.2W   65 KT  75 MPH...OVER WATER
60H  21/0000Z 20.7N  95.3W   75 KT  85 MPH
72H  21/1200Z 20.5N  97.7W   60 KT  70 MPH...INLAND
96H  22/1200Z 20.0N 103.0W   20 KT  25 MPH...POST-TROP/INLAND
120H  23/1200Z...DISSIPATED

$$
Forecaster Pasch

老農民版夜神月

正逐步建立底層,然而留給它的時間只剩大約18小時,就看造化了

FORECAST POSITIONS AND MAX WINDS

INIT  18/2100Z 19.7N  83.7W   70 KT  80 MPH
12H  19/0600Z 20.2N  86.1W   75 KT  85 MPH
24H  19/1800Z 20.7N  89.3W   55 KT  65 MPH...INLAND
36H  20/0600Z 20.9N  92.2W   60 KT  70 MPH...OVER WATER
48H  20/1800Z 20.8N  94.6W   70 KT  80 MPH...OVER WATER
60H  21/0600Z 20.4N  97.3W   75 KT  85 MPH...INLAND
72H  21/1800Z 20.0N  99.9W   30 KT  35 MPH...INLAND
96H  22/1800Z 19.5N 104.0W   20 KT  25 MPH...POST-TROP/INLAND
120H  23/1800Z...DISSIPATED

t02436

補充一下
中心已經在0945Z登陸猶加敦半島

ZCZC MIATCUAT2 ALL
TTAA00 KNHC DDHHMM

Hurricane Grace Tropical Cyclone Update
NWS National Hurricane Center Miami FL       AL072021
450 AM CDT Thu Aug 19 2021

...GRACE MAKES LANDFALL ALONG THE EASTERN YUCATAN PENINSULA
OF MEXICO NEAR TULUM...

Satellite images and radar data from Belize indicate that Hurricane
Grace made landfall along the eastern Yucatan Peninsula around 445
AM CDT...0945 UTC...just south of Tulum, Mexico.

A Weatherflow station at Xcaret Park near Playa del Carmen, Mexico,
recently measured a sustained wind of 60 mph (97 km/h) and a gust
to 85 mph (137 km/h). Another Weatherflow station located at
Cancun, Mexico, recently measured a sustained wind of 59 mph (95
km/h) and a gust to 80 mph (129 km/h), while the Weatherflow site
located at Puerto Morelos, Mexico, recently measured a sustained
wind of 51 mph (83 km/h) a gust to 70 mph (113 km/h). On Cozumel, a
sustained wind of 41 mph (66 km/h) and a gust to 68 mph (109 km/h)
was observed at the Cozumel Lighthouse.


SUMMARY OF 445 AM CDT...0945 UTC...INFORMATION
----------------------------------------------
LOCATION...20.1N 87.5W
ABOUT 10 MI...15 KM S OF TULUM MEXICO
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 17 MPH...28 KM/H
MINIMUM CENTRAL PRESSURE...986 MB...29.12 INCHES


$$
Forecaster Stewart/Berg


NNNN

15Z報預測12小時內會進入墨西哥灣，會再次增強挑戰第一次巔峰強度

FORECAST POSITIONS AND MAX WINDS

INIT  19/1500Z 20.2N  88.8W   55 KT  65 MPH
12H  20/0000Z 20.6N  91.2W   55 KT  65 MPH...OVER WATER
24H  20/1200Z 20.6N  94.0W   65 KT  75 MPH
36H  21/0000Z 20.4N  96.3W   75 KT  85 MPH
48H  21/1200Z 20.0N  98.7W   40 KT  45 MPH...INLAND
60H  22/0000Z 19.6N 101.7W   25 KT  30 MPH...POST-TROP/INLAND
72H  22/1200Z...DISSIPATED

$$
Forecaster Zelinsky

老農民版夜神月

NHC預測後期此系統有望進入東太,展望0%/60%

1. Tropical Storm Grace, located over the Yucatan Peninsula,
is forecast to move inland over mainland Mexico Friday night and
dissipate over Mexico by late Saturday.  However, Grace's remnants
are expected to continue westward and emerge over the eastern
Pacific Ocean off the west-central coast of Mexico early Sunday.  
Environmental conditions are forecast to be conducive for
development, and a tropical depression could form late this weekend
or early next week while the system moves westward at 10 to 15 mph
away from the coast of Mexico.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...60 percent.

老農民版夜神月

現正通過猶加敦半島,即將出海
出海後有36H的短暫發展時間,隨後旋即將再次登陸墨西哥

000
WTNT42 KNHC 192057
TCDAT2

Tropical Storm Grace Discussion Number  26
NWS National Hurricane Center Miami FL       AL072021
400 PM CDT Thu Aug 19 2021

Grace has now been inland for almost 12 hours and the inner core
structure has been gradually decaying. In fact, the low-level center
is now partially exposed to the north of the mid-level vortex which
still has the majority of the deep convection. The initial intensity
has been lowered to 45 kt this advisory, assuming a bit more
weakening of the low-level center has occurred since 1800 UTC.

Environmental conditions appear favorable for Grace to restrengthen
after the storm moves offshore this evening. However, it will take a
bit of time for the inner-core to reorganize before a faster rate of
intensification can occur. After that process occurs, significant
intensification is possible, and the latest intensity forecast makes
Grace a hurricane again by 24 hours and is near the upper end of the
intensity guidance by 36 hours when Grace will be just inland over
Mexico. However, it remains possible that the storm could intensify
more than indicated between the 24 and 36 hour points, when both the
global and regional high-res hurricane model guidance suggests Grace
will be near peak intensity.

Grace is still moving a bit north of due west at 280/13 kt. A
continued westward to west-northwestward motion is expected for the
next 6-12 hours and Grace should be emerging offshore of the western
Yucatan Peninsula later this evening. Thereafter, a strong mid-level
ridge oriented southwest-to-northeast ahead of Grace is likely to
steer the cyclone towards the west, and then west-southwest as it
nears mainland Mexico. The track guidance remains in good agreement,
and the latest track forecast is quite similar to the previous one,
staying close to the multi-model consensus aids. Although Grace is
likely to dissipate by 60 hours over the high terrain of Central
Mexico, the mid-level circulation should survive and emerge into the
East Pacific. This feature could contribute to the formation of a
new tropical cyclone in that basin.

Key Messages:

1. Tropical storm conditions will continue this afternoon and
evening across the northern Yucatan Peninsula but should subside
later tonight.

2. Hurricane conditions and dangerous storm surge are likely along
portions of eastern mainland Mexico beginning late Friday. A
Hurricane Warning is in effect from Puerto Veracruz northward to
Cabo Rojo.

3. Through the weekend, heavy rainfall across central and northern
portions of the Yucatan Peninsula and Veracruz State should lead to
flash and urban flooding. In addition, the heavy rainfall from Grace
will be capable of producing mudslides in Veracruz.


FORECAST POSITIONS AND MAX WINDS

INIT  19/2100Z 20.6N  90.2W   45 KT  50 MPH...INLAND
12H  20/0600Z 20.8N  92.5W   55 KT  65 MPH...OVER WATER
24H  20/1800Z 20.7N  94.9W   70 KT  80 MPH
36H  21/0600Z 20.4N  97.0W   75 KT  85 MPH...INLAND
48H  21/1800Z 19.6N  99.4W   35 KT  40 MPH...INLAND
60H  22/0600Z...DISSIPATED

$$
Forecaster Papin/Cangialosi