開啟輔助訪問
 找回密碼
 立即加入

17L.Ophelia 少見高緯MH 逐漸轉化

簽到天數: 153 天

[LV.7]常住居民III

2017-10-7 20:09 | 顯示全部樓層
本帖最後由 s6815711 於 2017-10-18 21:34 編輯

  三級颶風  
編號:17 L
名稱:Ophelia

  基本資料  
擾動編號日期:2017 10 07 18
命名日期  :2017 10 09 23
撤編日期  :2017 10 18 13
登陸地點  :暫無

  巔峰時期資料  
近中心最強風速
國家颶風中心(NHC):100 kts
海平面最低氣壓:960 毫巴

  過去路徑圖  

  擾動編號資料  

91L-INVEST-30kts-1010mb-32.7N-38.5W


20171007.1115.goes-13.ir.91L.INVEST.30kts.1010mb.32.7N.38.5W.100pc.jpg
NHC : 70%
1. A non-tropical area of low pressure is located about 700 miles
southwest of the Azores.  This system is beginning to acquire
subtropical characteristics, and environmental conditions are
expected to be conducive for the development of a tropical or
subtropical cyclone during the next day or so while the low drifts
toward the southwest.  Thereafter, the atmosphere is expected to
become hostile for further development.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...70 percent.

two_atl_2d1 (10).png

以上資料來自:NHC、颱風論壇整理製作

評分

參與人數 1水氣能量 +15 收起 理由
t02436 + 15

查看全部評分

簽到天數: 153 天

[LV.7]常住居民III

霧峰追風者|2017-10-9 16:55 | 顯示全部樓層
溫氣成功轉暖,NHC升格17L,逐漸增強,巔峰暫時上望50Kt。
000
WTNT42 KNHC 090833
TCDAT2

Tropical Depression Seventeen Discussion Number   1
NWS National Hurricane Center Miami FL       AL172017
500 AM AST Mon Oct 09 2017

The well-defined low pressure system over the eastern Atlantic
several hundred miles southwest of the Azores has maintained an
area of deep convection near and to the east of the center for the
past several hours.  Therefore, the system now meets the criteria
for a tropical depression.  The initial intensity is estimated to be
30 kt based on ASCAT data from around 0000 UTC and a 2.0/30 kt
Dvorak classification from TAFB.

The depression is moving slowly northward at 3 kt, and a continued
slow north to north-northeast motion is expected today.  A turn to
the east and then southeast is forecast to begin tonight and
continue through Wednesday while the cyclone is steered by the flow
on the east side of a subtropical ridge.  Thereafter, a mid- to
upper-level trough is expected to approach the depression, and that
should cause the system to move a little faster to the east and
east-northeast.  The NHC track forecast lies near the middle of the
guidance envelope, in agreement with various consensus aids, and
keeps the system far from any land areas.

The depression is currently over marginally warm 27 deg C SSTs and
in an environment of moderate to strong westerly shear.   The
models suggest that the shear will likely let up a little during the
next couple of days, which could allow the depression to gradually
strengthen while it remains over relatively warm waters.  After that
time, the shear could increase again, but the amount of shear
depends on the exact track of the tropical cyclone.  There is a fair
amount of spread in the models at the longer range with the regional
models (HWRF, HMON, and COAMPS-TC) bringing the system to hurricane
strength while the statistical SHIPS and LGEM models show a much
weaker system.  The NHC intensity forecast leans toward the more
conservative side of the guidance for now, but it should be noted
that confidence in the intensity forecast is low.

FORECAST POSITIONS AND MAX WINDS

INIT  09/0900Z 31.1N  39.9W   30 KT  35 MPH
12H  09/1800Z 31.5N  39.8W   35 KT  40 MPH
24H  10/0600Z 31.7N  39.0W   35 KT  40 MPH
36H  10/1800Z 31.5N  38.4W   40 KT  45 MPH
48H  11/0600Z 31.0N  37.8W   45 KT  50 MPH
72H  12/0600Z 29.7N  37.0W   50 KT  60 MPH
96H  13/0600Z 29.7N  35.5W   50 KT  60 MPH
120H  14/0600Z 31.0N  32.0W   50 KT  60 MPH

$$
Forecaster Cangialosi
083755_5day_cone_no_line_and_wind.png rgb-animated (18).gif rbtop-animated (22).gif


回復

使用道具 舉報

簽到天數: 588 天

[LV.9]以壇為家II

Meow|2017-10-9 22:56 | 顯示全部樓層
命名Ophelia,有望連十颶。
144414_5day_cone_with_line_and_wind.png
000
WTNT42 KNHC 091438
TCDAT2

Tropical Storm Ophelia Discussion Number   2
NWS National Hurricane Center Miami FL       AL172017
1100 AM AST Mon Oct 09 2017

The convective pattern of the small cyclone has continued to improve
since the previous advisory, with some thunderstorm activity having
developed near or over the center, along with an increase in curved
banding features in the eastern semicircle. The Dvorak intensity
estimate at 1200Z from TAFB was T2.0/30 kt, but given the
aforementioned improvement in the curved-band structure since that
time, the initial intensity is increased to 35 kt. This makes
Ophelia the fifteenth named storm of the 2017 Atlantic hurricane
season.

The initial motion estimate is 030/04 kt. The steering flow
surrounding Ophelia is expected to continue to be weak for the next
day or so while the cyclone remains entangled with a weak
upper-level low located just to its north and northwest. As a
result, only a slow drift toward the northeast and and east is
forecast. By 36 h, increased mid-level ridging to the northwest of
Ophelia should induce a motion toward the east-southeast and
southeast through 72 h, after which a broad mid-latitude trough is
expected to gradually accelerate the cyclone toward the northeast at
a forward speed of near 10 kt. The official forecast remains down
the middle of the guidance envelope, in close agreement with the
previous forecast track, and the HCCA and TVCX consensus models.
Ophelia should remain far away from land for the next 5 days.

Although Ophelia is forecast to remain over marginally warm SSTs of
26.5-27 deg C, much colder-than-normal temperatures aloft should
offset the relatively cool ocean temperatures and produce sufficient
instability to generate moderate to strong convection for the next
120 h. The GFS-based SHIPS model is currently assessing 25 kt of
westerly vertical wind shear, which obviously isn't occuring based
on the recent development of anticyclonic outflow over the low-level
center and across most of Ophelia's circulation. In contrast, the
UW-CIMSS shear analyses indicate lower shear values near 15 kt.
However, both shear assessments are likely too high given the large
domains that they use to calculate environmental wind shear. Based
on recent trends noted in water vapor imagery showing the shear
decreasing, along with the overall favorable upper-level wind fields
forecast by the GFS and ECMWF, especially after 36 hours, slow but
steady strengthening is expected for the next 5 days, with only
occasional intrusions of dry mid-level air being the primary
inhibiting factor to the intensification process. The official
intensity forecast is close to the NOAA HCCA consensus model, is
about midway between the more aggressive IVCN consensus model that
makes Ophelia a hurricane in about 72 h, and the more conservative
statistical SHIPS and LGEM models. However, even the SHIPS and LGEM
models have increased their peak intensity forecasts by at least 15
kt since the previous advisory.

FORECAST POSITIONS AND MAX WINDS

INIT  09/1500Z 31.4N  39.9W   35 KT  40 MPH
12H  10/0000Z 31.7N  39.5W   40 KT  45 MPH
24H  10/1200Z 31.6N  38.7W   45 KT  50 MPH
36H  11/0000Z 31.3N  38.1W   45 KT  50 MPH
48H  11/1200Z 30.7N  37.7W   50 KT  60 MPH
72H  12/1200Z 29.8N  36.7W   55 KT  65 MPH
96H  13/1200Z 30.5N  34.5W   65 KT  75 MPH
120H  14/1200Z 32.0N  31.0W   65 KT  75 MPH

$$
Forecaster Stewart
回復

使用道具 舉報

簽到天數: 153 天

[LV.7]常住居民III

霧峰追風者|2017-10-11 21:12 | 顯示全部樓層
風眼開啟,強度升一級颶風。
20171011.1215.goes-13.irbd.17L.OPHELIA.65kts.987mb.30N.36.7W.100pc.jpg avn-animated (1).gif

回復

使用道具 舉報

簽到天數: 1556 天

[LV.Master]伴壇終老

t02436|2017-10-12 11:51 | 顯示全部樓層
補充 21Z正式站上颶風級別。
FORECAST POSITIONS AND MAX WINDS

INIT  11/2100Z 30.0N  36.1W   65 KT  75 MPH
12H  12/0600Z 30.3N  35.7W   70 KT  80 MPH
24H  12/1800Z 30.7N  35.2W   75 KT  85 MPH
36H  13/0600Z 31.4N  34.1W   75 KT  85 MPH
48H  13/1800Z 32.3N  31.9W   70 KT  80 MPH
72H  14/1800Z 35.5N  24.5W   70 KT  80 MPH
96H  15/1800Z 43.0N  16.0W   65 KT  75 MPH...POST-TROP/EXTRATROP
120H  16/1800Z 53.5N  10.5W   60 KT  70 MPH...POST-TROP/EXTRATROP

2100.png

GOES03302017285Nk3jOW.jpg

rb-animated.gif
回復

使用道具 舉報

簽到天數: 579 天

[LV.9]以壇為家II

蜜露|2017-10-13 01:08 | 顯示全部樓層



There have been no aircraft reconnaissance missions in the past 6 hours.





我曾說過, 大西洋的每個颶風幾乎都會有颶風獵人觀察.

但如果高緯和對美洲大陸無害的颶風, 就可能會跳過此颶風.

就像上次的李(Lee) , 這次的奧菲莉亞 . 就是選擇不實測.

而且這兩個颶風還真有點像. 兩者B環都沒有. 實際強度或許比德法推算強度還高也說不定.
回復

使用道具 舉報

簽到天數: 153 天

[LV.7]常住居民III

霧峰追風者|2017-10-13 08:35 | 顯示全部樓層
最新一報,強度到達顛峰,預計將加速東北移動,趨向愛爾蘭。
000
WTNT42 KNHC 122037
TCDAT2

Hurricane Ophelia Discussion Number  15
NWS National Hurricane Center Miami FL       AL172017
500 PM AST Thu Oct 12 2017

Ophelia's structure has continued to improve during the afternoon.
The eye of the hurricane has cleared and is surrounded by a ring of
cloud tops colder than -55 deg C.  Dvorak classifications from TAFB
and the UW-CIMSS ADT have increased accordingly, and on that basis
the initial intensity has been increased to 85 kt.  Ophelia is
nearly stationary, which could cause the hurricane to stop
strengthening, or even weaken slightly during the next 12 to 24
hours due to upwelling effects.  That said, the intensity guidance
is in good agreement that Ophelia will remain at hurricane strength
for the next 48 h while it remains in a fairly unstable, low-shear
environment.  Beyond that time, extratropical transition will begin,
though baroclinic forcing will likely keep post-tropical Ophelia
near hurricane strength as it approaches Ireland and the UK.  The
new intensity forecast is very similar to the previous advisory, and
is generally close to the multi-model intensity consensus.

Although Ophelia is currently stationary, a mid-latitude trough
should cause it to begin moving toward the east-northeast within
about 24 hours.  The cyclone will then accelerate on that heading in
the faster mid-latitude westerly flow ahead of the trough, before
turning toward the northeast around day 3 as extratropical
transition occurs and the hurricane becomes entangled with the
southern extent of the trough.  Confidence in the track forecast is
fairly high for the first 72 h, and all of the dynamical guidance is
tightly clustered through this period.  The model spread increases
substantially at 96 h and beyond.  As a post-tropical cyclone,
Ophelia will continue to interact with the southern extent of the
trough, and should turn toward the northeast as a result of this
interaction.  However, the details of this turn vary greatly from
model to model.  The new NHC forecast has been nudged slightly
toward the east at this time range, closer to the UKMET and ECMWF
models, as well as the corrected consensus aids HCCA and FSSE.

While the track guidance keeps the center of Ophelia south and east
of the Azores, tropical-storm-force winds are possible throughout
the Azores by Sunday due to an approaching front.  In addition, the
wind field of Ophelia will likely expand as the cyclone begins
extratropical transition, and any deviation to the left of the
forecast track could bring stronger winds to the islands.  Interests
in the Azores should refer to products issued by the Azores Weather
Forecast and Watch Center.

KEY MESSAGES:

1. Ophelia is expected to transition to a hurricane-force post-
tropical cyclone by Monday when it moves near Ireland and the
United Kingdom.  While post-tropical Ophelia will likely bring some
direct impacts from wind and heavy rain to portions of these areas,
as well as dangerous marine conditions, given the forecast
uncertainty at these time ranges it is too soon to determine the
exact magnitude, timing and location of the impacts.  Residents in
Ireland and the United Kingdom should monitor the progress of
Ophelia for the next several days.  For more information on local
impacts, residents of Ireland should refer to products issued by Met
Eireann and residents in the United Kingdom should refer to products
issued by the Met Office.


FORECAST POSITIONS AND MAX WINDS

INIT  12/2100Z 30.4N  35.5W   85 KT 100 MPH
12H  13/0600Z 31.0N  34.6W   85 KT 100 MPH
24H  13/1800Z 31.9N  32.6W   80 KT  90 MPH
36H  14/0600Z 33.2N  29.6W   75 KT  85 MPH
48H  14/1800Z 35.0N  25.6W   75 KT  85 MPH
72H  15/1800Z 42.6N  17.1W   75 KT  85 MPH
96H  16/1800Z 53.0N  10.0W   65 KT  75 MPH...POST-TROP/EXTRATROP
120H  17/1800Z 62.5N   2.0W   55 KT  65 MPH...POST-TROP/EXTRATROP

$$
Forecaster Zelinsky

204406_5day_cone_no_line_and_wind.png rbtop-animated.gif

回復

使用道具 舉報

簽到天數: 1556 天

[LV.Master]伴壇終老

t02436|2017-10-13 11:53 | 顯示全部樓層
03Z再上調強度到90節。
000
WTNT42 KNHC 130250
TCDAT2

Hurricane Ophelia Discussion Number  16
NWS National Hurricane Center Miami FL       AL172017
1100 PM AST Thu Oct 12 2017

Remarkably, the hurricane has continued to strengthen this evening.
Satellite images indicate that cloud tops in the eyewall have cooled
in the past several hours, with a warm eye remaining.  Dvorak
estimates from TAFB, SAB and CIMSS range between 90 to 95 kt, so the
initial intensity is raised to 90 kt.

It seems that the marginal SSTs that Ophelia has been moving over
have been offset by the cold upper-level temperatures and low shear
environment.  SSTs only slightly cool in the next 24 hours with
similar shear conditions, so a minor decrease in strength is in the
forecast.  After that time, while the hurricane should move over
colder waters, it will likely be accelerating to the northeast and
experiencing favorable mid-latitude jet dynamics, which will help to
maintain the cyclone's intensity.  All of the guidance show
extratropical transition by 3 days with the cyclone keeping
hurricane-force winds, as indicated in the new forecast. Little
change was made to the previous prediction, except to account for
the higher initial wind speed.

Ophelia is finally moving, estimated at 6 kt to the east-northeast.
This general motion with an increase in forward speed is expected
for the next couple of days as the hurricane gets picked up by a
large mid-latitude trough.  Confidence in the track forecast remains
fairly high for the first 72 h, although the spread increases after
that time.  The GFS-based guidance generally then show a more
northward track to the west of Ireland then over the far North
Atlantic, while the UKMET/ECMWF show a track over Ireland and Great
Britain then eastward and dissipating over northern Europe.
The forecast is close to the consensus at long range, but some large
changes could be required for later forecasts.

While the NHC track keeps the center of Ophelia south and east
of the Azores, tropical-storm-force winds are possible throughout
the Azores by Saturday night due to an approaching front.  In
addition, the wind field of Ophelia will likely expand as the
cyclone begins extratropical transition, and any deviation to the
left of the forecast track could bring stronger winds to the
islands. Interests in the Azores should refer to products issued by
the Azores Weather Forecast and Watch Center.

KEY MESSAGES:

1. Ophelia is expected to transition to a hurricane-force post-
tropical cyclone by Monday when it moves near Ireland and the
United Kingdom.  While post-tropical Ophelia will likely bring some
direct impacts from wind and heavy rain to portions of these areas,
as well as dangerous marine conditions, given the forecast
uncertainty at these time ranges it is too soon to determine the
exact magnitude, timing and location of the impacts.  Residents in
Ireland and the United Kingdom should monitor the progress of
Ophelia for the next several days.  For more information on local
impacts, residents of Ireland should refer to products issued by Met
Eireann and residents in the United Kingdom should refer to products
issued by the Met Office.


FORECAST POSITIONS AND MAX WINDS

INIT  13/0300Z 30.7N  34.7W   90 KT 105 MPH
12H  13/1200Z 31.2N  33.5W   90 KT 105 MPH
24H  14/0000Z 32.2N  31.1W   85 KT 100 MPH
36H  14/1200Z 33.7N  27.5W   80 KT  90 MPH
48H  15/0000Z 36.0N  23.0W   80 KT  90 MPH
72H  16/0000Z 45.0N  14.5W   75 KT  85 MPH...POST-TROP/EXTRATROP
96H  17/0000Z 56.0N   7.0W   55 KT  65 MPH...POST-TROP/EXTRATROP
120H  18/0000Z 64.0N   0.5W   50 KT  60 MPH...POST-TROP/EXTRATROP

$$
Forecaster Blake

025501_5day_cone_with_line_and_wind.png

20171013.0315.goes-13.ircolor.17L.OPHELIA.90kts.970mb.30.5N.35.1W.100pc.jpg

GOES03152017286aw5tMe.jpg

回復

使用道具 舉報

12下一頁
快速回覆
您需要登錄後才可以回帖 登錄 | 立即加入

本版積分規則

霧峰追風者

    主題

    帖子

    111萬

    積分

    14級[二級颶風]

    Rank: 14Rank: 14Rank: 14Rank: 14

14級[二級颶風]

發私訊

本平台僅供學術討論之用,預報應以氣象局為準

威普網站虛擬主機贊助公司

台灣第一個天氣類型社群平台 即時天氣資訊、精準颱風動態 淺顯易懂地球科學科科普教育


線上客服
FB訊息傳送
廣告行銷
精準行銷 物超所值
官方粉專
發佈 快速回復 返回頂部 返回列表