周子堯@FB

  熱帶風暴  
編號：11 E
名稱：Ileana

  基本資料  
擾動編號日期：2018 年 08 月 04 日 20 時
升格熱低日期：2018 年 08 月 05 日 05 時
命名日期　　：2018 年 08 月 06 日 05 時
撤編日期　　：2018 年 08 月 00 日 00 時
登陸地點　　：無

  巔峰時期資料  
近中心最強風速 ： 55  kt
海平面最低氣壓 ：998 百帕

  過去路徑圖  

  討論帖圖片  
96E.INVEST.20kts.1009mb.12.0N.94.0W


NHC:30%  

3. A tropical wave located a few hundred miles south-southwest of the
coast of Guatemala continues to produce disorganized shower
activity. Although this system has the potential to become a
tropical depression early next week, strong upper-level winds from
another disturbance to the west could prevent tropical cyclone
formation while the system moves westward or west-northwestward
south of Mexico.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...medium...40 percent.

以上資料來自：NHC、颱風論壇整理製作

霧峰追風者

NHC 展望提升至50%

3. Updated: Satellite images indicate that a low pressure area has
formed a few hundred miles south of the Gulf of Tehuantepec, and
the system is already showing signs of organization.  A tropical
depression could form over the next day or two while the system
moves westward or west-northwestward nearly parallel to the coast of
Mexico. Interests along the southern coast of Mexico should monitor
the progress of this system.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...medium...60 percent.

霧峰追風者

發展迅速，NHC 6小時內展望提升至90%，即將升格。

3. Satellite images indicate that a low pressure area located about 275
miles south-southeast of Puerto Angel, Mexico, has become
significantly better defined this morning, and a tropical depression
could be forming.  If current trends continue, advisories could be
initiated this afternoon or evening on this system.  The low is
forecast to move west-northwestward at 10 to 15 mph, relatively
close to Mexico, and interests along the southern coast of Mexico
should monitor the progress of this system.  Heavy rainfall and
gusty winds could affect coastal regions of Guerrero northwestward
to Jalisco over the next few days.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

霧峰追風者

NHC 升格熱帶低壓11E，巔峰上望50KT。

280
WTPZ41 KNHC 042034
TCDEP1

Tropical Depression Eleven-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP112018
400 PM CDT Sat Aug 04 2018

Satellite images indicate that the disturbance located over the far
eastern Pacific has become significantly better organized
throughout the day, with the formation of a well-defined low
pressure center and deep convection organized in a distinct curved
band.  Based on these criteria, the system is being designated as a
tropical depression, and the initial intensity is set at 25 kt in
accordance with Dvorak estimates from TAFB and SAB.

Because the system has congealed so quickly, the initial motion is
uncertain but estimated to be 285/11 kt.  The cyclone's future
motion will ultimately be dictated by a large mid-tropospheric
ridge to its north and its proximity to another disturbance located
about 450 n mi to the west.  A west-northwestward motion at a
nearly constant speed is expected during the next 2-3 days due to
the ridge.  After that time, the cyclone could begin to slingshot
around the northern side of the larger weather system to its west.
Many of the track models are not handling the depression very well;
the GFS barely depicts a surface low from the get-go, and the HWRF
does not appear to be accounting sufficiently for the possibility of
binary interaction.  As a result, the NHC official track forecast
matches the consensus of the ECMWF and UKMET, the only two models
which appear to have a decent grasp on the situation.

Although the depression will be moving over very warm waters of
29-30 degrees Celsius over the next 2-3 days, the upper-level wind
environment may not be ideal due to possible outflow from the larger
disturbance to the west.  As a result, the official intensity
forecast is not too aggressive and is essentially close to the ICON
intensity consensus.  Even though the ECMWF and UKMET were used for
the track forecast, the two models disagree on the cyclone's
ultimate demise.  The ECMWF has the system absorbed by the other
disturbance by day 4, while the UKMET keeps it distinct and holds it
just beyond the forecast period.  As a compromise, the official
forecast shows dissipation or absorption by day 5, but the
confidence in this forecast is low.

Based on the forecast, tropical-storm-force winds are expected to
remain offshore the coast of Mexico.  However, only a slight
deviation in the forecast track or an increase in size could bring
those winds closer to the coast, and interests along the southern
and southwestern coast of Mexico should monitor the progress of the
depression.

FORECAST POSITIONS AND MAX WINDS

INIT  04/2100Z 12.4N  95.0W   25 KT  30 MPH
12H  05/0600Z 12.9N  96.4W   30 KT  35 MPH
24H  05/1800Z 13.6N  98.3W   35 KT  40 MPH
36H  06/0600Z 14.3N 100.2W   40 KT  45 MPH
48H  06/1800Z 15.3N 102.4W   45 KT  50 MPH
72H  07/1800Z 18.3N 107.8W   50 KT  60 MPH
96H  08/1800Z 20.0N 114.0W   45 KT  50 MPH
120H  09/1800Z...DISSIPATED

$$
Forecaster Berg

霧峰追風者

NHC 命名"Ileana"，將沿著墨西哥西岸北上。

185
WTPZ41 KNHC 052034
TCDEP1

Tropical Storm Ileana Discussion Number   5
NWS National Hurricane Center Miami FL       EP112018
400 PM CDT Sun Aug 05 2018

The cyclone has continued to become better organized today, with a
fairly symmetrical shape on geostationary imagery.  Data from a
recent ASCAT overpass showed that the center was embedded about in
the middle of a small CDO-like feature.  The scatterometer data
indicated maximum winds of 35-40 kt, and Dvorak classifications from
TAFB and SAB gave intensity estimates of 35 kt and 45 kt,
respectively.  Blending these various estimates yields a current
intensity of about 40 kt, and the tropical cyclone is thus being
named.  Since the system should be in a warm water and low shear
environment for the next couple of days, some additional
strengthening is forecast.  However a strengthening cyclone is
situated not far to the west of Ileana.  This larger system is
forecast by the ECMWF and GFS models to become the dominant cyclone
in a few days, and cause the tropical storm to dissipate near the
northern side of the larger circulation.  That is the scenario shown
by the official intensity forecast.

There is more confidence in the center position than there was
earlier today, and the estimated initial motion is
west-northwestward or 285/9 kt.  Over the next couple of days,
Ileana is likely to move between a mid-level ridge to its north and
northeast and the larger cyclonic circulation to its west and
southwest.  The official track forecast is on the southern side of
the track guidance envelope.  It is also very close to the latest
HCCA forecast track.

Interests along the coast of southern and southwestern Mexico
should monitor the progress of this system, given the uncertainties
in the forecast.

FORECAST POSITIONS AND MAX WINDS

INIT  05/2100Z 13.6N  98.1W   40 KT  45 MPH
12H  06/0600Z 14.5N 100.0W   45 KT  50 MPH
24H  06/1800Z 16.2N 102.3W   50 KT  60 MPH
36H  07/0600Z 17.9N 104.6W   50 KT  60 MPH
48H  07/1800Z 19.2N 106.7W   45 KT  50 MPH
72H  08/1800Z...DISSIPATED

$$
Forecaster Pasch

霧峰追風者

逐漸併入John環流內。

223
WTPZ41 KNHC 062034
TCDEP1

Tropical Storm Ileana Discussion Number   9
NWS National Hurricane Center Miami FL       EP112018
400 PM CDT Mon Aug 06 2018

There have been significant changes to the forecast reasoning for
Ileana.  Recent satellite imagery suggest that the system is being
adversely affected by the large circulation of John much sooner
than anticipated.  In fact, Ileana is looking more like an outer
band of John at this time.  Nonetheless, a recent ASCAT overpass
indicated that Ileana is still a separate system to the
east-northeast of John and continues to support a current intensity
of 55 kt.  However given the evolution of Ileana today, the
previous NHC short-term intensity forecast is reversed.  Ileana
is no longer predicted to become a hurricane, and the tropical
cyclone is likely to dissipate or become absorbed by John's
circulation in 24-36 hours. It should be noted that some models,
such as the HWRF, GFS, and ECMWF depict Ileana's demise even sooner
than that.

Since the cloud pattern of Ileana has become rather disorganized,
it is difficult to track a center and the initial motion is an
uncertain 305/15 kt.  The cyclone should move between a mid-level
ridge and the circulation of John until dissipation.  The official
track forecast is a little left of the previous one, but a little to
the right of the track model consensus.

The 34- and 50-kt wind radii have been adjusted based on the
scatterometer data.

The hurricane watch for the southwest coast of Mexico is
discontinued.  The tropical storm watch for the extreme southern
Baja California peninsula is also discontinued for Ileana, but a
watch for this same general are may soon be required for John.


FORECAST POSITIONS AND MAX WINDS

INIT  06/2100Z 17.0N 103.3W   55 KT  65 MPH
12H  07/0600Z 18.2N 105.8W   55 KT  65 MPH
24H  07/1800Z 19.5N 109.0W   45 KT  50 MPH
36H  08/0600Z...DISSIPATED

$$
Forecaster Pasch

t02436

NHC判定已經成為John的養分。

ZCZC MIATCDEP1 ALL
TTAA00 KNHC DDHHMM

Remnants Of Ileana Discussion Number  12
NWS National Hurricane Center Miami FL       EP112018
900 AM MDT Tue Aug 07 2018

Early morning GOES-16 one-minute satellite imagery confirms that
the small circulation of Ileana has dissipated within the northern
portion of Hurricane John's larger circulation. As a result, this
is the final NHC advisory on Ileana.  The remnants of the tropical
cyclone are likely producing an area of tropical-storm-force
winds that should gradually decrease in intensity as it rotates
around the northern and northwestern portion of John during the
next few hours.


FORECAST POSITIONS AND MAX WINDS

INIT  07/1500Z 20.5N 109.0W   40 KT  45 MPH...REMNANTS
12H  08/0000Z...DISSIPATED

$$
Forecaster Brown

NNNN