NHC判定登陸墨西哥

000
WTPZ41 KNHC 131452
TCDEP1

Tropical Storm Pamela Discussion Number  14
NWS National Hurricane Center Miami FL       EP162021
900 AM MDT Wed Oct 13 2021

Pamela is estimated to have made landfall around 1200 UTC close to
Estacion Dimas in the Mexican state of Sinaloa as a 65-kt hurricane.
To the southeast of the landfall location, observations from the
Mazatlan Airport indicated wind gusts to 40 kt had occurred. There
was also a storm chaser located at Marmor de Salcido, Mexico, who
measured a minimum pressure of 990.8 mb with southeasterly winds to
20 kt at 1208 UTC. Thus, based on these data, the estimated landfall
location and an estimated minimum central pressure of 987 mb appears
reasonable. Vigorous deep convection is still occuring around
Pamela's estimated center as it moves farther inland. However, since
the center has been onshore for a few hours now, the wind field is
likely starting to spin down and maximum sustained winds are
estimated to have decreased to 55 kt.

The tropical cyclone has been accelerating to the northeast this
morning, with the latest estimated motion at 045/20 kt. Further
acceleration to the northeast is expected as the system remains
embedded in deep-layer southwesterly flow between a long-wave trough
over the western United States and a mid-level ridge centered over
the Gulf of Mexico. The track guidance is in good agreement on this
solution with the storm losing its identity after the 12-h forecast
period and the latest track forecast remains close to the model
consensus solutions.

Pamela's circulation is not forecast to survive the passage over
the high, rugged terrain of Central Mexico, but its remnants are
expected to contain a large slug of deep-layer moisture that will be
advected northeastward into the south-central United States.
Additional heavy rainfall and flooding impacts are anticipated later
today and on Thursday for these areas.


FORECAST POSITIONS AND MAX WINDS

INIT  13/1500Z 24.4N 106.0W   55 KT  65 MPH...INLAND
12H  14/0000Z 26.6N 102.7W   30 KT  35 MPH...INLAND
24H  14/1200Z...DISSIPATED INLAND

NHC降格TS

INIT  13/0300Z 21.9N 108.7W   60 KT  70 MPH
12H  13/1200Z 23.8N 106.9W   70 KT  80 MPH...NEAR THE COAST
24H  14/0000Z 26.6N 103.3W   30 KT  35 MPH...INLAND
36H  14/1200Z 29.7N  99.7W   20 KT  25 MPH...POST-TROP/INLAND
48H  15/0000Z...DISSIPATED

NHC升格C1

003
WTPZ41 KNHC 120834
TCDEP1

Hurricane Pamela Discussion Number   9
NWS National Hurricane Center Miami FL       EP162021
300 AM MDT Tue Oct 12 2021

After being relatively steady in strength for the past 12 hours or
so, satellite images indicate that Pamela has resumed intensifying.
A large area of deep convection has developed during the past
several hours, and the center is estimated to be located near the
middle of the convective mass.  The Dvorak classifications from TAFB
and SAB have both increased to 4.0/65 kt, and therefore, Pamela has
now been upgraded to a 65-kt hurricane. An Air Force Reserve
reconnaissance aircraft is scheduled to fly into the storm later
this morning and early afternoon to provide a better assessment of
Pamela's structure, intensity, and wind field.

Pamela has made the expected turn to the north, with the latest
initial motion estimated to be 360/10 kt.  The system is now on the
western periphery of the ridge, which should cause it to continue
moving northward today.  However, by tonight, Pamela is forecast to
become embedded in the flow on the south side of a broad mid- to
upper-level trough, and that feature should cause the hurricane to
move faster to the northeast toward the coast of west-central
Mexico. After the storm moves inland early Wednesday, Pamela, or its
remnants should accelerate northeastward across central and northern
Mexico by the end of the week.  The NHC track forecast is similar to
the previous one and near the middle of the guidance envelope.

Even though Pamela has not strengthened as quickly as thought up to
this point, the overall intensity forecast philosophy has not
changed much.  The storm is expected to be in generally favorable
conditions to gain strength until it reaches the coast of Mexico in
24 to 36 hours.  Therefore, the NHC forecast continues to predict
steady to rapid strengthening, and Pamela is likely to be near major
hurricane intensity when it makes landfall.  After landfall, Pamela
is expected to rapidly decay due to the rugged terrain of Mexico,
and it should ultimately dissipate over northern Mexico in 2 to 3
days.  The NHC intensity forecast lies at the high end of the model
guidance.

Although the cyclone is forecast to dissipate over the mountainous
terrain of Mexico, deep moisture associated with the system's
remnants are likely to spread over north-central and northeastern
Mexico on Wednesday, and then move into portions of the
south-central United States late Wednesday or Thursday.

Key Messages:

1. Pamela is forecast to be near major hurricane intensity when it
reaches the west-central coast of Mexico on Wednesday morning, and
life-threatening storm surge and dangerous hurricane-force winds
are expected within the Hurricane Warning area.  Residents in this
area should follow any advice given by local officials.

2. Pamela is expected to pass south of the southern tip of the Baja
California peninsula as a hurricane later today an tonight,
and tropical-storm conditions are possible within the Tropical
storm Watch area.

3. Heavy rains associated with Pamela are expected to move into the
Mexican States of Sinaloa and western Durgano along with southern
portions of Baja California Sur later today and Wednesday. This will
pose a threat of significant and life-threatening flash flooding and
mudslides.

4. Heavy rains associated with the remnants of Pamela are expected
across portions of central Texas and southeastern Oklahoma late
Wednesday and Thursday.  This may result in flash and urban
flooding.


FORECAST POSITIONS AND MAX WINDS

INIT  12/0900Z 19.2N 108.9W   65 KT  75 MPH
12H  12/1800Z 20.5N 108.8W   75 KT  85 MPH
24H  13/0600Z 22.4N 107.6W   90 KT 105 MPH
36H  13/1800Z 25.1N 105.1W   50 KT  60 MPH...INLAND
48H  14/0600Z 28.4N 101.3W   30 KT  35 MPH...POST-TROP/REMNT LOW
60H  14/1800Z...DISSIPATED

NHC升格TD16E

000
WTPZ41 KNHC 100858
TCDEP1

Tropical Depression Sixteen-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP162021
400 AM CDT Sun Oct 10 2021

The system we have been monitoring over the last several days off
the southern coast of Mexico has been gradually improving in
organization. An earlier ASCAT-A pass at 0257 UTC indicated that a
closed surface vortex was developing, especially after investigating
the ambiguity wind solutions from the instrument. In addition, the
0600 UTC subjective Dvorak from TAFB was at T2.0/30 kt, which is in
good agreement with the peak winds (29 kt) from the earlier
scatterometer data. Since that time, convection near the estimated
center has only increased in coverage and intensity. Therefore,
advisories are being initiated on TD16-E, the first tropical
cyclone in the East Pacific basin in nearly a month. The initial
intensity has been set at 30 kt in agreement with the scatterometer
and satellite intensity estimate.

The current motion of the depression is estimated at 290/15 kt,
though some uncertainty exists given the system is in its formative
stages. At present, the cyclone is situated on the equatorward side
of an expensive mid-level ridge centered over Mexico that stretches
westward into the East Pacific. This ridge should continue to steer
the tropical cyclone to the west-northwest over then next day or so.
Thereafter, a strong shortwave trough is forecast to dig into the
western United States, creating a pronounced weakness in the
mid-level ridge steering the system. The net result of this synoptic
pattern change is that the tropical cyclone will likely bend
sharply right as the ridge becomes oriented to its east, leading to
a turn north to then northeastward in the 48-72 hour forecast. This
track evolution would likely steer the system to the mainland
Mexican coast in around 96 hours. The latest track guidance is in
pretty good agreement on the general track, though investigating the
GFS and ECMWF ensembles solutions reveals significant uncertainty
in the along-track spread of the current forecast track. The
initial NHC track forecast has been chosen to lie near the consensus
aids, splitting the difference between the TVCA and HCCA solutions.

The environment over the depression appears quite favorable for
intensification, with low shear (around 10 kt) high mid-level
moisture (around 70 percent) and warm sea-surface temperatures
(29-30 C) expected to persist for the next three days. It may take
12-24 hours for an inner core to become established, but after this
structural change occurs, the system appears poised for substantial
intensification. In fact, the latest GFS-SHIPS guidance indicates a
44 percent chance of a 65 knot increase in intensity over the next
72 hours. The first NHC intensity forecast follows suit, showing a
peak intensity of 95 kt in 72 hours. It is worth noting that this
intensity forecast is less than some of the more bullish guidance,
including the latest HFIP corrected consensus approach (HCCA) and
this initial forecast could be conservative.


FORECAST POSITIONS AND MAX WINDS

INIT  10/0900Z 14.3N 102.9W   30 KT  35 MPH
12H  10/1800Z 15.1N 105.0W   35 KT  40 MPH
24H  11/0600Z 15.8N 107.2W   45 KT  50 MPH
36H  11/1800Z 16.6N 108.6W   60 KT  70 MPH
48H  12/0600Z 17.8N 109.6W   75 KT  85 MPH
60H  12/1800Z 19.0N 109.8W   85 KT 100 MPH
72H  13/0600Z 20.7N 109.4W   95 KT 110 MPH
96H  14/0600Z 25.2N 106.4W   75 KT  85 MPH...INLAND
120H  15/0600Z...DISSIPATED

NHC展望提升至100%

1. Showers and thunderstorms associated with an area of low pressure
located a few hundred miles south of the southern coast of Mexico
continue to become better organized. Recent satellite wind data
also suggests that the circulation is becoming better defined.
Environmental conditions are conducive for additional development,
and a tropical depression or tropical storm is expected to form
later today while the system moves west-northwestward at about 15
mph south of the coast of Mexico.  Additional information on this
system, including gale warnings, can be found in High Seas Forecasts
issued by the National Weather Service.
* Formation chance through 48 hours...high...near 100 percent.
* Formation chance through 5 days...high...near 100 percent.

NHC展望提升至90%

1. Showers and thunderstorms associated with a broad area of low
pressure located a few hundred miles south of the southern coast of
Mexico are gradually becoming better organized.  Environmental
conditions are conducive for additional development, and a tropical
depression or tropical storm is expected to form within the next
day or so while the system moves west-northwestward at about 15 mph
south of the coast of Mexico.  Additional information on this
system, including gale warnings, can be found in High Seas
Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.