0908morakot

  基本資料  
編號　　　　：24 E
擾動編號日期：2018 年 10 月 17 日 19 時
撤編日期　　：2018 年 10 月 00 日 00 時
99E.INVEST.25kts.1007mb.12.2N.90.5W


  NHC:80%  

1. Satellite-derived winds and surface observations indicate that an
elongated low pressure system has developed about 100 miles south of
Guatemala.  Although associated shower and thunderstorm activity is
currently disorganized, environmental conditions are expected to be
conducive for additional development, and a tropical depression or a
tropical storm is likely to form during the next day or two.  The
system is forecast to moves generally toward the west-northwest at
10 to 15 mph, near or just offshore the coast of southern Mexico.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...90 percent.

周子堯@FB

NHC升格24E

ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM

Tropical Depression Twenty-Four-E Discussion Number   2
NWS National Hurricane Center Miami FL       EP242018
400 AM CDT Sat Oct 20 2018

Various satellite data indicate that the area of low pressure that
NHC has been monitoring off the coast of southern Mexico for thew
past few days has acquired enough convective organization to be
designated as a tropical depression, the twenty-fourth one of the
very busy 2018 eastern North Pacific hurricane season. Although the
depression is a sheared system, some banding features have recently
developed south of the center, while overshooting cloud tops just
west of the center are quite cold -85 to -91 deg C). The initial
intensity is set to 30 kt based on a satellite intensity estimate of
T2.0/30 kt from both TAFB and SAB.

The initial motion estimate is 280/08 kt, based primarily on passive
microwave fixes and GOES-16 nighttime imagery. A gradual turn toward
the west-northwest is expected by this afternoon, followed by a
slower northwestward motion on Sunday as the system moves along the
southwestern periphery of a weakening mid-level ridge. A slow
northwestward motion is expected to continue into early next week
while the ridge to the north changes little.  On days 4 and 5,
however, a series of weak shortwave troughs are forecast to move
through the larger scale southwesterly flow locked in over the
southwestern U.S. and northern Mexico, causing an erosion of the
western portion of the ridge, which should allow the cyclone to
gradually recurve northward and north-northeastward. The NHC model
guidance is in good agreement overall on this developing track
scenario, and the official forecast track lies between the HCCA and
TVCE track consensus aids.

The depression is expected to steadily strengthen during the next 96
hours due to very favorable environmental conditions consisting of
low vertical wind shear (less than 10 kt), high amounts of mid-level
moisture, and warm 28-30 deg C SSTs.  As a result, the cyclone is
expected to become a tropical storm later this morning, a hurricane
by Sunday night, and be near major hurricane strength by Wednesday.
Given the very favorable conditions expected on Sunday and Monday,
there is a fair chance of rapid intensification occurring similar to
that depicted by the COAMPS-TC and HMON models, which bring the
cyclone to category-4 status around 72 hours. The NHC official
intensity forecast near the HCCA and IVCN consensus models through
96 hours, and then a little above the guidance at 120 hours despite
an increase in the shear expected at that time.

FORECAST POSITIONS AND MAX WINDS

INIT  20/0900Z 15.1N 104.9W   30 KT  35 MPH
12H  20/1800Z 15.5N 105.7W   40 KT  45 MPH
24H  21/0600Z 15.9N 106.6W   50 KT  60 MPH
36H  21/1800Z 16.5N 107.4W   60 KT  70 MPH
48H  22/0600Z 17.1N 108.0W   75 KT  85 MPH
72H  23/0600Z 18.0N 109.0W   90 KT 105 MPH
96H  24/0600Z 19.2N 109.4W  100 KT 115 MPH
120H  25/0600Z 21.7N 108.5W   95 KT 110 MPH

$$
Forecaster Stewart

t02436

已快速增強到85節，上望120。

000
WTPZ44 KNHC 211443
TCDEP4

Hurricane Willa Discussion Number   6
NWS National Hurricane Center Miami FL       EP242018
900 AM MDT Sun Oct 21 2018

First-light GOES-16 visible satellite imagery shows that Willa
continues to become better organized, with a tightly coiled band
of convection wrapping around the center.  There has also been
evidence of a small eye in recent microwave and infrared satellite
pictures.  Subjective and objective satellite intensity estimates
range from 77 kt to 90 kt, and the initial intensity has been
increased to 85 kt for this advisory.

Willa is moving northwestward or 325/6 kt. The track guidance
continues to indicate that Willa will move northwestward today,
then turn northward on Monday, and then head north-northeastward
on Tuesday between a deep-layer ridge that extends westward from the
Gulf of Mexico and an approaching mid-level trough. The dynamical
model guidance remains in good overall agreement on this scenario,
but there are differences in how quickly Willa will accelerate
north-northeastward.  The UKMET and ECMWF are much slower than the
remainder of the dynamical models, with the GFS and GFS ensemble
mean the fastest.  The NHC track forecast brings the center of the
Willa onshore of the coast of southwestern Mexico within 72 h, and
it lies closest to the HFIP corrected consensus, which is a little
faster than the other consensus aids.

The hurricane is expected to remain within low vertical wind shear
and over warm waters of around 28 degrees Celsius during the next
day or two.  These very favorable conditions are expected to allow
steady to rapid strengthening through Monday night, and the NHC
forecast is near the upper end of the intensity guidance.  By 48
hours, increasing southwesterly shear is forecast to initiate
weakening, but Willa is likely to remain a very strong hurricane
through landfall in southwestern Mexico.  After landfall, rapid
weakening and dissipation over the mountainous terrain of mainland
Mexico should occur.

Key Messages:

1. Willa is forecast to be a hurricane when it reaches the coast of
southwestern mainland Mexico by late Tuesday or Wednesday bringing a
life-threatening storm surge, dangerous winds, and life-threatening
flash flooding, and hurricane and tropical storm watches are now
in effect for a portion of the area.  Residents in the watch areas
should monitor the progress of this system and follow any advice
given by local officials.


FORECAST POSITIONS AND MAX WINDS

INIT  21/1500Z 16.6N 106.7W   85 KT 100 MPH
12H  22/0000Z 17.2N 107.2W   95 KT 110 MPH
24H  22/1200Z 18.2N 107.6W  110 KT 125 MPH
36H  23/0000Z 19.3N 107.7W  120 KT 140 MPH
48H  23/1200Z 20.4N 107.5W  110 KT 125 MPH
72H  24/1200Z 23.3N 105.5W   80 KT  90 MPH...INLAND
96H  25/1200Z 26.5N 101.0W   20 KT  25 MPH...POST-TROP/INLAND
120H  26/1200Z...DISSIPATED

$$
Forecaster Brown

霧峰追風者

風眼開啟，00z強度升四級颶風。

t02436

06Z評價135節，相當有機會衝擊C5

000
WTPZ34 KNHC 220538
TCPEP4

BULLETIN
Hurricane Willa Intermediate Advisory Number 8A
NWS National Hurricane Center Miami FL       EP242018
1200 AM MDT Mon Oct 22 2018

...WILLA RAPIDLY INTENSIFIES TO NEAR-CATEGORY 5 STRENGTH...
...EXPECTED TO PRODUCE LIFE-THREATENING STORM SURGE, WIND, AND
RAINFALL OVER PORTIONS OF WEST-CENTRAL AND SOUTHWESTERN MEXICO...


SUMMARY OF 1200 AM MDT...0600 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.9N 107.1W
ABOUT 195 MI...315 KM SSW OF CABO CORRIENTES MEXICO
MAXIMUM SUSTAINED WINDS...155 MPH...250 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...931 MB...27.49 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* San Blas to Mazatlan, including Las Islas Marias

A Tropical Storm Warning is in effect for...
* Playa Perula to San Blas
* North of Mazatlan to Bahia Tempehuaya

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area.  A warning is typically issued
36 hours before the anticipated first occurrence of
tropical-storm-force winds, conditions that make outside
preparations difficult or dangerous.  Preparations to protect life
and property should be rushed to completion.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

Interests elsewhere along the coasts of west-central and
southwestern mainland Mexico should monitor the progress of Willa.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1200 AM MDT (0600 UTC), the eye of Hurricane Willa was located
near latitude 17.9 North, longitude 107.1 West. Willa is moving
toward the north near 5 mph (7 km/h), and this general motion is
expected to continue today. Willa is forecast to accelerate toward
the north-northeast and move over or very near the Islas Marias on
Tuesday and make landfall along the southwestern coast of mainland
Mexico in the hurricane warning area Tuesday night or Wednesday
morning.

Maximum sustained winds have increased to near 155 mph (250 km/h)
with higher gusts.  Willa is an extremely dangerous category 4
hurricane on the Saffir-Simpson Hurricane Wind Scale. Additional
strengthening is expected today, and Willa could become a category
5 hurricane later this morning. While some weakening is forecast by
tonight and Tuesday, Willa is expected to be a dangerous hurricane
when it reaches the coast of Mexico late Tuesday or early Wednesday.

Hurricane-force winds extend outward up to 25 miles (35 km) from
the center and tropical-storm-force winds extend outward up to 90
miles (150 km).

The estimated minimum central pressure is 931 mb (27.49 inches).


HAZARDS AFFECTING LAND
----------------------
STORM SURGE:  A dangerous storm surge is likely along portions of
the coast of southwestern Mexico by Tuesday or Tuesday night,
especially near and to the south of where the center of Willa makes
landfall. Near the coast, the surge will be accompanied by large and
destructive waves.

RAINFALL:  Willa is expected to produce storm total rainfall
accumulations of 6 to 12 inches, with local amounts to 18 inches,
across portions of western Jalisco, western Nayarit, and southern
Sinaloa in Mexico.  This rainfall will cause life-threatening flash
flooding and landslides.

Farther inland, Willa is expected to produce rainfall amount of 2 to
4 inches across portions of Zacateca, Durango, southeast Chihuahua,
and Coahuila in Mexico, with local amounts to 6 inches possible.
This rainfall could cause life-threatening flash flooding.

WIND:  Hurricane conditions are expected within the hurricane
warning area by late Tuesday, with tropical storm conditions
expected by Tuesday morning. Tropical storm conditions are expected
within the tropical storm warning areas tonight and Tuesday.

SURF:  Large swells generated by Willa will continue to affect
portions of the coast of southwestern and west-central Mexico
during the next few days. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 300 AM MDT.

$$
Forecaster Stewart

t02436

12Z評價140節，15Z正報維持評價，正式站上C5！

000
WTPZ44 KNHC 221515 CCA
TCDEP4

Hurricane Willa Discussion Number  10...corrected
NWS National Hurricane Center Miami FL       EP242018
900 AM MDT Mon Oct 22 2018

Corrected wording in Key Messages number 2

Willa is an extremely impressive hurricane in infrared and visible
satellite imagery this morning.  The small, but very distinct, eye
is embedded within a symmetric central dense overcast with cloud
tops of -70 to -80 degrees Celsius.  A very recent SSMIS microwave
overpass is the first to indicate that an outer eyewall has formed,
suggesting that an eyewall replacement cycle has started.  The
latest objective T-numbers from UW-CIMSS are T7.0/140 kt, and
subjective Dvorak intensity estimates from TAFB and SAB are 140 kt
and 127 kt, respectively.  Based on these data the initial intensity
has been increased to 140 kt.  An Air Force Reserve Hurricane Hunter
aircraft is currently en route to Wilma and should provide a better
assessment of the storm's intensity by early this afternoon.

Willa is moving northward 6 kt.  The hurricane is forecast to
continue to move northward today around the western flank of a
deep-layer ridge that is located over the Gulf of Mexico.
A short wave trough that is seen in water vapor imagery near 130W
longitude is forecast to deepen as it moves eastward toward Baja
California.  This should cause Willa to turn north-northeastward
tonight, then accelerate northeastward on Tuesday, bringing the
center of the hurricane onshore along the west-central coast of
Mexico Tuesday afternoon or evening.  As mentioned in the previous
advisory, the track guidance is good agreement on the overall
scenario but there are still some notable differences in the
predicted forward speed of the hurricane.  The NHC track forecast
leans toward the faster solutions of the GFS and GFS ensemble
mean, which have been handling Willa's track the best so far.

The environment of low wind shear and water temperatures of 28
to 29.5 degrees Celsius suggest some additional strengthening is
possible but with the evidence that an eyewall replacement has
begun, some fluctuations intensity are possible during the next 12
to 24 hours.  After that time, increasing southwesterly shear is
forecast to induce weakening, but Willa is likely to remain an
extremely dangerous major hurricane when it makes landfall along the
west-central coast of Mexico.  After landfall, shear and the
mountainous terrain of Mexico will cause rapid weakening and
dissipation of the cyclone.

Key Messages:

1. A life-threatening storm surge is expected Tuesday along the
coasts of the Isla Marias, and west-central and southwestern
Mexico near the path of Willa.  Residents should rush preparations
to completion to protect life and property and follow any advice
given by local officials.

2. Everyone in Isla Marias, and within the hurricane warning area
along coast of west-central Mexico should prepare for life-
threatening major hurricane winds associated with the core of
Willa.  Hurricane force winds will also extend inland across the
mountainous areas of west-central Mexico as Willa moves inland.

3. Heavy rainfall from Willa is likely to produce life-threatening
flash flooding and landslides over much of southwestern and
west-central Mexico.


FORECAST POSITIONS AND MAX WINDS

INIT  22/1500Z 19.1N 107.2W  140 KT 160 MPH
12H  23/0000Z 20.1N 107.2W  140 KT 160 MPH
24H  23/1200Z 21.4N 106.9W  135 KT 155 MPH
36H  24/0000Z 23.1N 105.6W   90 KT 105 MPH...INLAND
48H  24/1200Z 25.4N 102.5W   30 KT  35 MPH...INLAND
72H  25/1200Z...DISSIPATED

$$
Forecaster Brown

t02436

減弱到115節，持續接近陸地，一天以內登陸。

000
WTPZ44 KNHC 230838
TCDEP4

Hurricane Willa Discussion Number  13
NWS National Hurricane Center Miami FL       EP242018
300 AM MDT Tue Oct 23 2018

Willa's overall satellite presentation has continued to slowly
degrade since the previous advisory, with the exception of a few
brief attempts at redevelopment of an inner-core ring of deep
convection. However, dry intrusions from the moat region between the
larger outer eyewall and the smaller inner core have thus far
prevented the reformation of an inner eyewall. Satellite intensity
estimates have been steadily decreasing, and the advisory intensity
is set at 115 kt, based on a average of the subjective T- and
CI-numbers from TAFB and a UW-CIMSS ADT objective estimate of
T6.0/115 kt. An Air Force Reserve Unit reconnaissance aircraft is
scheduled to reconnoiter Hurricane Willa later this morning,
providing more detailed intensity information.

The initial motion estimate remains northward, but at a slower
forward speed, or 360/04 kt. There are no significant changes to the
previous track forecast or reasoning. Willa is expected to move
slowly northward this morning around the western periphery of a
deep-layer ridge located over central Mexico, and then recurve
toward the north-northeast and northeast at a faster forward speed
by this afternoon ahead of an approaching mid-latitude trough, with
that motion continuing into this evening and Wednesday. The new NHC
track forecast is near the eastern edge of the tightly packed
guidance envelope, near the FSSE and GFS model tracks.

There has been no microwave imagery since around 0100Z to provide
information on the eyewall replacement cycle (ERC). However,
conventional infrared satellite imagery suggests that the ERC is
still ongoing based on the appearance of a partial moat or clear
region in the northern semicircle of the inner core. Willa is
currently moving over warmer and deeper water as indicated by
upper-ocean heat content (UOHC) values greater than 50 units. This
favorable ocean condition is expected to continue along the forecast
track for another 12 hours or so, which could help to offset the
weakening rate due to the gradual increase in the southwesterly wind
shear. By 18 h, or just before landfall, the shear is forecast to
increase to more than 20 kt and the warm water beneath the hurricane
is expected to become more shallow, a combination that could lead to
significant upwelling and weakening. However, the official intensity
forecast follows the consensus of the various intensity models,
keeping Willa's intensity near 100 kt at landfall, which is similar
to the FSSE and HCCA corrected-consensus models. Despite the
forecast decrease in the peak winds, Willa is expected to remain a
dangerous major hurricane through landfall, bringing
life-threatening storm surge, wind, and rainfall hazards to Las
Islas Marias and portions of west-central and southwestern Mexico
later today. After moving inland, Willa will rapidly weaken, with
dissipation forecast by Wednesday over the high terrain of Mexico.
However, deep moisture from the remnants of Willa is forecast to
spread northeastward over northern Mexico and portions of Texas
where a swath of heavy rainfall is expected midweek.

Key Messages:

1. A life-threatening storm surge is expected today along the coasts
of the Isla Marias, and along the coast of southern Sinaloa and
Nayarit states in west-central and southwestern Mexico near the
path of Willa. Residents should rush preparations to completion to
protect life and property and follow any advice given by local
officials.

2. Everyone in the Isla Marias, and within the hurricane warning
area along the coast of west-central Mexico should prepare for life-
threatening major hurricane winds associated with the core of
Willa. Hurricane force winds will also extend inland across the
mountainous areas of west-central Mexico as Willa moves inland.

3. Heavy rainfall from Willa is likely to produce life-threatening
flash flooding and landslides over much of southwestern and
west-central Mexico.


FORECAST POSITIONS AND MAX WINDS

INIT  23/0900Z 20.8N 107.3W  115 KT 130 MPH
12H  23/1800Z 22.0N 106.5W  100 KT 115 MPH
24H  24/0600Z 23.8N 104.5W   40 KT  45 MPH...INLAND
36H  24/1800Z 25.8N 102.3W   20 KT  25 MPH...POST-TROP/INLAND
48H  25/0600Z...DISSIPATED INLAND

$$
Forecaster Stewart

newyou_huang

t02436 發表於 2018-10-23 19:45
減弱到115節，持續接近陸地，一天以內登陸。

是不是在眼牆置換