t02436

  四級颶風  
    編號：08 L
    名稱：Gonzalo

  基本資料     
　擾動編號日期：2014 年 10 月 10 日 20 時
　命名日期　　：2014 年 10 月 13 日 07 時
　消散日期　　：2014 年 10 月 20 日 00 時
　登陸地點　　：暫無

  巔峰時期資料  
　近中心最強風速 / 海平面最低氣壓
    國家颶風中心 (NHC) ：  125   kts  ( CAT.4 )   
    海平面最低氣壓          ：  940  百帕
  過去路徑圖  

  討論帖圖片  
90L.INVEST.25kts.1012mb.13.3N.49.2W


以上資料來自 : NHC、颱風論壇整理製作

krichard2011

NHC 評級 HIGH
整體螺旋性算是相當好
不過對流方面還有待加強
數值大致看好後期進入大西洋發展

Updated: The small low pressure system located a couple of hundred
miles east of the Leeward Islands is continuing to show signs of
organization. An Air Force Reserve reconnaissance aircraft will
be investigating the system this afternoon to determine if a
tropical depression or a tropical storm has formed. Environmental
and ocean conditions are expected to generally be conducive for
additional development while the low moves westward at 10 to 15 mph.
Interests from the Leeward Islands and Puerto Rico to Hispaniola and
the southeastern Bahamas should monitor the progress of this system
since tropical storm warnings and watches could be required for
portions of the Leeward Islands, the Virgin Islands, and Puerto Rico
later this morning or afternoon. Regardless of development, locally
heavy rainfall and strong gusty winds are expected to move across
the Leeward Islands starting later today.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

krichard2011

實測命名GONZALO 後期看 C2 上限...

000
WTNT43 KNHC 122054
TCDAT3

TROPICAL STORM GONZALO DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL082014
500 PM AST SUN OCT 12 2014

The Air Force Reserve reconnaissance aircraft investigating Gonzalo
this afternoon has found found 850-mb maximum flight-level winds of
47 kt in the northeastern quadrant along with reliable SFMR surface
winds of 39-41 kt. The aircraft also measured a central pressure of
1003-1004 mb and on-board radar indicated that a primitive eye with
a diameter of 10 n mi was developing. Based on these data, the
initial intensity has been increased to 40 kt, which could be a
little conservative.

The initial motion estimate is 270/10 kt based on reconnaissance
data. There is no significant change to the previous track forecast
or reasoning. A strong deep-layer ridge to the north of Gonzalo
should keep the cyclone moving westward at around 10 kt for the next
24 hours, followed by a gradual turn to the west-northwest by 36
hours. By 72 hours, a strong mid-latitude trough is expected to move
off of the U.S. east coast and act to erode the ridge to the north
of Hispaniola, allowing Gonzalo to move slowly northwestward to
northward into the weakness in the ridge. The NHC model guidance is
in general agreement on this developing track scenario, but there is
considerable spread in the model tracks after 36 hours. The GFS and
the regional models keep Gonzalo weak until after 48 hours, and take
the system well to the east of Puerto Rico and the Virgin Islands.
In contrast, the ECMWF and the UKMET show a vertically deep and more
robust tropical cyclone moving more westward in deep-layer easterly
steering flow. Since the official forecast calls for Gonzalo to
become a hurricane within 48 hours, the NHC forecast track lies near
the extreme western edge of the model envelope and close to the more
robust ECMWF model solution.

The combination of the small size of Gonzalo, its precursor eye
feature, low vertical wind shear conditions, SSTs at least 29C, and
colder than normal upper-tropospheric temperatures support at least
a normal rate of intensification throughout the forecast period.
Although occasional intrusions of dry mid-level air could briefly
disrupt the strengthening process, those occurrences should
generally be short-lived due to the strong instability conditions
that will be present. In fact, rapid intensification is a very
distinct possibility, especially if the aforementioned eye feature
continues to develop. The NHC intensity forecast is higher then the
consensus models and follows the a blend of the SHIPS and LGEM
models.

NOTE: Data from the reconnaissance aircraft has been received by the
NHC, but telecommunications problems continue to prevent the
dissemination of these data.

FORECAST POSITIONS AND MAX WINDS

INIT  12/2100Z 16.4N  59.5W   40 KT  45 MPH
12H  13/0600Z 16.5N  61.1W   45 KT  50 MPH
24H  13/1800Z 16.9N  63.1W   50 KT  60 MPH
36H  14/0600Z 17.9N  65.0W   60 KT  70 MPH
48H  14/1800Z 19.0N  66.4W   70 KT  80 MPH
72H  15/1800Z 20.9N  67.9W   80 KT  90 MPH
96H  16/1800Z 22.6N  68.3W   90 KT 105 MPH
120H  17/1800Z 24.5N  68.0W   95 KT 110 MPH

$$
Forecaster Stewart

krichard2011

看起來正在建立底層風眼 @@
甚至從可見光也疑似看到疑似風眼的情形? (or 根本就是風眼? @@
環境也還算相當不錯
數值也挺支持的...不排除有機會挑戰 C3

krichard2011

從雷達來看的話
眼牆大致已經建構完成
中心附近的對流也有爆發的跡象
如果風眼順利清空 強度應該就會開始上衝了

krichard2011

現在的底層算是相當漂亮...
高層眼也快開了 @@
沒意外的話 這底層應該算是近期最漂亮的
NHC 甚至上看C4... 原本預測今年大西洋偏向不活躍
或是打算走少量精緻路線?
如成真 將是北大西洋今年第二個MH

000
WTNT43 KNHC 140855
TCDAT3

HURRICANE GONZALO DISCUSSION NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL082014
500 AM AST TUE OCT 14 2014

Air Force Hurricane Hunter aircraft data indicate that Gonzalo
has continued to quickly strengthen overnight while the eye has
passed just northeast of the British Virgin Islands.  The aircraft
measured a peak flight-level wind of 116 kt in the northeastern
eyewall and SFMR surface winds of 92 kt. A blend of these data yield
an initial intensity of 95 kt for this advisory.  The SHIPS model
and a UW-CIMSS shear analysis show about 15 to 20 kt of south-
southwesterly shear over Gonzalo, which may be why the eye has not
become apparent in infrared imagery.  The shear is forecast to
decrease and remain low during the next few days while the hurricane
moves over warm water. This should allow for additional
strengthening during the next 12 to 24 hours. Eyewall cycles are
likely to cause some fluctuations in intensity after that time. In
about 3 days, gradual weakening is predicted to begin as Gonzalo
will be moving over gradually decreasing sea surface temperatures
and into an area of increasing southwesterly shear.  The updated NHC
intensity forecast is close to the SHIPS guidance, and is a little
higher than the previous advisory through 72 hours due to the
higher initial intensity.

Gonzalo is moving northwestward or 315/11 kt.  The hurricane is
expected to remain on a northwestward heading during the next 24 to
36 hours.  After that time, Gonzalo should turn northward, then
north-northeastward ahead a mid-latitude trough that is forecast to
move off the east coast of the United States in 2 to 3 days. Late
in the period, the hurricane should accelerate northeastward in
deep layer southwesterly flow over the North Atlantic.  The track
guidance is in good agreement on this scenario, but there remains
some spread in the forward speed of the hurricane after 72 hours.
The new NHC track forecast is similar to the previous advisory and
is close to the GFEX and TVCA consensus models.

FORECAST POSITIONS AND MAX WINDS

INIT  14/0900Z 19.6N  64.4W   95 KT 110 MPH
12H  14/1800Z 21.0N  65.6W  105 KT 120 MPH
24H  15/0600Z 22.7N  67.1W  110 KT 125 MPH
36H  15/1800Z 24.1N  68.3W  115 KT 130 MPH
48H  16/0600Z 25.4N  68.7W  110 KT 125 MPH
72H  17/0600Z 28.9N  67.3W  105 KT 120 MPH
96H  18/0600Z 34.5N  64.0W   95 KT 110 MPH
120H  19/0600Z 43.5N  56.5W   85 KT 100 MPH

$$
Forecaster Brown

Meow

風眼很不錯了，有機會成為四級颶風。







FORECAST POSITIONS AND MAX WINDS

INIT  14/1500Z 20.3N  65.2W   95 KT 110 MPH
12H  15/0000Z 21.7N  66.4W  100 KT 115 MPH
24H  15/1200Z 23.3N  67.8W  110 KT 125 MPH
36H  16/0000Z 24.6N  68.6W  120 KT 140 MPH
48H  16/1200Z 26.1N  68.6W  115 KT 130 MPH
72H  17/1200Z 30.4N  66.5W  105 KT 120 MPH
96H  18/1200Z 37.4N  62.6W   90 KT 105 MPH
120H  19/1200Z 46.8N  53.8W   70 KT  80 MPH...POST-TROP/EXTRATROP

krichard2011

結構相當不錯 風眼轉清晰
今年第二隻MH終於又達成了...
底層結構相當強悍 結構應該算是近年來最好的
稍早實測也算是相當給力... 高空測到 125KT的風力
地面也有約110~115KT 的風力
稍後強度應該還會在提升 不排除稍後會直升C4 持續上看120KT

000
WTNT43 KNHC 142041
TCDAT3

HURRICANE GONZALO DISCUSSION NUMBER  10
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL082014
500 PM AST TUE OCT 14 2014

Data from an Air Force Reserve Hurricane Hunter aircraft earlier
today indicated flight-level and SFMR wind data that were just below
the threshold of a major hurricane. On the last flight leg, the
aircraft measured a central pressure of 971 mb, which was down 2 mb
from what was measured at the start of the mission. The eye had also
contracted from a 20 nmi diameter down to about 16 nmi on the last
report. Recent data from the NOAA Doppler radar in San Juan indicate
that the eye has contracted to about 15 nmi at an altitude of about
36,000 ft since the aircraft departed a few hours ago, signifying
that the eye diameter is likely smaller at lower altitudes. In
addition, satellite imagery indicates that the eye has cleared out
and warmed while cloud tops have cooled significantly in the
surrounding eyewall. Based on the trends noted in the radar and
satellite data, the intensity has been increased to 100 kt, which is
supported by a UW-CIMSS ADT value of T5.4/100 kt.

Gonzalo continues to move steadily northwestward with a motion of
320/11 kt. The NHC model guidance is tightly packed and remains is
in excellent agreement on Gonzalo moving steadily northwestward
around the periphery of a deep-layer ridge located to its north
during the next 36 hours or so. By 48 hours, a deep mid-tropospheric
trough and cold front are expected to move eastward across the
Bahamas and weaken the western portion of the ridge. This should
allow the cyclone to turn slowly northward, and then accelerate
northeastward by 72 hours ahead of the aforementioned trough and
front, with the hurricane potentially threatening Bermuda on Day 3.
Gonzalo is expected to merge with the cold front or become
extratropical by 120 hours. The new track forecast is just an update
of the previous advisory track, and lies close to a blend of the
GFEX and TVCA consensus models.

With the eye of Gonzalo having contracted and become more distinct
in satellite, radar, and recon wind data, the system appears primed
for intensification into a category 4 hurricane later tonight or
on Wednesday. Sea-surface temperatures ahead of the cyclone are
sufficiently warm enough at 28C-28.5C to support a category 4
hurricane through at least the next 36 hours. The global models
continue to indicate that the best vertical shear conditions and 200
mb upper-level outflow pattern are expected to occur on Wednesday
and continue into Thursday morning. Afterwards, eyewall cycles and
possible cold upwelling beneath the hurricane are likely to cause
some fluctuations in the intensity. By 72 hours, increasing vertical
wind shear ahead of the aforementioned deep trough is expected to
induce weakening. By 120 hours, Gonzalo will be over sub-20C SSTs in
the North Atlantic and experiencing vertical shear of 50-60 kt,
which should result in the cyclone becoming an extratropical low.
The NHC intensity forecast is similar to the previous advisory and
remains above all of the available intensity guidance.

FORECAST POSITIONS AND MAX WINDS

INIT  14/2100Z 21.2N  66.0W  100 KT 115 MPH
12H  15/0600Z 22.5N  67.1W  110 KT 125 MPH
24H  15/1800Z 24.0N  68.2W  115 KT 130 MPH
36H  16/0600Z 25.4N  68.7W  120 KT 140 MPH
48H  16/1800Z 27.2N  68.3W  110 KT 125 MPH
72H  17/1800Z 32.0N  65.6W  100 KT 115 MPH
96H  18/1800Z 39.9N  60.4W   85 KT 100 MPH
120H  19/1800Z 49.0N  50.0W   65 KT  75 MPH...POST-TROP/EXTRATROP