墨西哥以南热带风暴“克丽丝蒂”(12E.Kristy) - 持续西行，数值支持发展

桑美和伊欧凯

ygsj24 发表于 2024-10-22 04:44
000
WTPZ42 KNHC 212044
TCDEP2

对抗风切加强，算是很坚强了

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全球热带气旋监测公报
预报：柳龙生  签发：王皘  2024 年 10 月 22 日 10 时
东北太平洋热带风暴“克丽丝蒂”生成

时       间：22日08时（北京时）

海       域：东北太平洋

命       名：“克丽丝蒂”，KRISTY

中心位置：北纬13.4度、西经102.6度

强度等级：热带风暴

最大风力：8级（18米/秒，相当于我国的热带风暴级）

中心气压：1005百帕

参考位置：墨西哥科利马州曼萨尼约南偏东方向约660公里的洋面上

变化过程：“克丽丝蒂”生成并加强到8级

预报结论：“克丽丝蒂”将以每小时25-30公里的速度向偏西方向快速移动，强度逐渐增强。


图1 卫星红外监测图像（北京时间2024年10月22日08时00分）

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WTPZ42 KNHC 220242
TCDEP2

Tropical Storm Kristy Discussion Number   2
NWS National Hurricane Center Miami FL       EP122024
900 PM CST Mon Oct 21 2024

Kristy is becoming better organized this evening.  Bursts of deep
convection are wrapping around the western semicircle of the
circulation with upper-level outflow also present in this region.
Subjective and objective Dvorak estimates range between 35 to 53 kt.
The initial intensity for this advisory is raised to 40 kt, closest
to the UW-CIMSS DMINT objective Dvorak estimate.

The tropical storm is heading westward at 270/14 kt.  This general
motion should continue through Thursday while Kristy moves along the
southern side of a subtropical ridge.  By Friday and Saturday, the
storm will reach a weakness in the ridge caused by a cutoff low
over the north Pacific and gradually turn west-northwestward to
northwestward.  The latest track forecast is quite similar to the
previous forecast and lies near the various consensus aids.  

The fragmented convection seen on satellite infrared imagery seems
to indicate that there is a dry air intrusion possibly slowing
Kristy's present organization.  However, atmospheric and oceanic
conditions are quickly becoming more conducive for significant to
rapid intensification.  Statistical guidance from SHIPS-RII is
showing a high chance (72 percent) of 25 kt of strengthening in 24
h.  Therefore, the latest NHC intensity forecast now explicitly
forecasts this increase, making Kristy a hurricane on Tuesday and
nudging up the peak to 100 kt in 60 h.  On Friday and Saturday, the
vertical wind shear is expected to increase and induce a weakening
trend.  This intensity forecast lies in the middle of the guidance
envelope, between the HCCA and the previous prediction.


FORECAST POSITIONS AND MAX WINDS

INIT  22/0300Z 13.7N 103.3W   40 KT  45 MPH
12H  22/1200Z 13.9N 105.4W   50 KT  60 MPH
24H  23/0000Z 14.2N 108.5W   65 KT  75 MPH
36H  23/1200Z 14.2N 111.9W   80 KT  90 MPH
48H  24/0000Z 14.2N 115.4W   95 KT 110 MPH
60H  24/1200Z 14.1N 118.6W  100 KT 115 MPH
72H  25/0000Z 14.4N 121.6W  100 KT 115 MPH
96H  26/0000Z 16.4N 126.7W   90 KT 105 MPH
120H  27/0000Z 19.7N 131.0W   75 KT  85 MPH

$$
Forecaster Bucci

冰凌蔷薇

RMW较小

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全球热带气旋监测公报
预报：柳龙生  签发：王皘  2024 年 10 月 22 日 18 时
“克丽丝蒂”向偏西方向移动

时       间：22日14时（北京时）

海       域：东北太平洋

命       名：“克丽丝蒂”，KRISTY

中心位置：北纬13.7度、西经104.0度

强度等级：热带风暴

最大风力：8级（20米/秒，相当于我国的热带风暴级）

中心气压：1003百帕

参考位置：墨西哥科利马州曼萨尼约偏南方向约600公里的洋面上

变化过程：过去24小时，“克丽丝蒂”由6级加强到8级

预报结论：“克丽丝蒂”将以每小时25-30公里的速度向偏西方向移动，强度逐渐增强。


图1 卫星红外监测图像（北京时间2024年10月22日14时00分）

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WTPZ42 KNHC 220835
TCDEP2

Tropical Storm Kristy Discussion Number   3
NWS National Hurricane Center Miami FL       EP122024
300 AM CST Tue Oct 22 2024

Satellite images indicate that Kristy has continued to gradually
become better organized during the overnight hours.  A convective
burst has been occurring over the low-level center, an indication
that a central core could be forming.  The cyclone also has some
impressive curved banding to the north and west, although these
bands are a bit far from the center.  A pair of ASCAT passes from
22/0346 UTC and 22/0441 UTC showed tropical storm force winds in
the northern semi-circle, with vectors in the 35 to 38 kt range.  
Since the time of the ASCAT passes, Kristy's convection has become
better organized, with latest subjective Dvorak intensity estimates
from TAFB and SAB at a consensus T-3.0/45 kt.  The initial intensity
is nudged upward to 45 kt for this advisory.

Kristy is estimated to be moving west-northwestward, or 285/13 kt.
A strong subtropical ridge to the north of the cyclone will steer
it westward for the next 3 days or so.  Friday into the weekend, a
turn to the west-northwest or northwest is expected as Kristy rounds
the western periphery of the mid to upper-level ridge, and a
mid-latitude upper-level trough approaches from the west.  The track
forecast is largely unchanged from the previous official forecast
and lies in the middle of the guidance envelope.  It should be noted
that there is quite a bit of spread in the track guidance at days 4
and 5, so confidence in this part of the forecast is a bit below
average.

Environmental conditions are favorable for steady strengthening,
and rapid intensification cannot be ruled out.  For the next
72 h, Kristy will remain within an environment of warm ocean
temperatures, relatively weak vertical wind shear, and a moist
troposphere.  Beyond 72 h, southerly or southwesterly vertical wind
shear will begin to increase over the cyclone, becoming strong in 4
to 5 days.  Kristy should also cross the 26C isotherm in about 4
days and move into a much more stable environment.  Therefore,
weakening should begin in 3 to 4 days, with the potential for rapid
weakening in 4 to 5 days.  The intensity forecast is largely
unchanged from the previous prediction, which calls for Kristy to
peak at 100 kt in a few days, and lies near the middle of the
guidance envelope.


FORECAST POSITIONS AND MAX WINDS

INIT  22/0900Z 14.2N 104.8W   45 KT  50 MPH
12H  22/1800Z 14.3N 107.1W   60 KT  70 MPH
24H  23/0600Z 14.4N 110.4W   70 KT  80 MPH
36H  23/1800Z 14.3N 113.8W   85 KT 100 MPH
48H  24/0600Z 14.2N 117.2W   95 KT 110 MPH
60H  24/1800Z 14.3N 120.3W  100 KT 115 MPH
72H  25/0600Z 14.8N 123.0W  100 KT 115 MPH
96H  26/0600Z 17.1N 127.9W   90 KT 105 MPH
120H  27/0600Z 20.3N 131.6W   65 KT  75 MPH

$$
Forecaster Hagen

理可的呆萌呆毛

一張掃偏，一張4K解析度

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WTPZ42 KNHC 221454
TCDEP2

Tropical Storm Kristy Discussion Number   4
NWS National Hurricane Center Miami FL       EP122024
800 AM MST Tue Oct 22 2024

Kristy still appears to be on an intensification trend this morning.
The storm's structure on satellite imagery is quite well organized,
with a large curved band on its western side, and a smaller central
dense overcast that suggests a formative inner core may be
developing.  There has not been much passive microwave imagery for
a more in-depth look at the convective structure since the prior
advisory, but based on a blend of the subjective Dvorak intensity
estimates (T3.0/45 kt from TAFB and T3.5/55 kt from SAB), the
initial intensity is being increased to 50 kt for this advisory.

The tropical storm is moving a little north of due west this
morning, with the motion estimated at 280/15 kt. A well-established
subtropical mid-level ridge should continue to steer the tropical
cyclone westward, with some of the guidance even showing a little
farther south of due west over the next 48-60 h. By this weekend,
the ridge becomes eroded towards its western edge by a mid- to
upper-level trough that should allow Kristy to begin gaining
latitude on Friday into the weekend. The track forecast this cycle
is nearly on top of the previous NHC track forecast for the first 48
h, and is a little to the south and west thereafter, blending the
consensus aids TCVE and HCCA with the prior track at the end of the
forecast period.

As alluded to in previous discussions, the environment appears quite
favorable for intensification, with low shear, warm sea-surface
temperatures, and a moist surrounding environment. In fact, rapid
intensification is becoming a distinct possibility as the storm
forms an inner core. Indeed, the latest ECMWF-SHIPS guidance is
giving Kristy a 43 percent chance of a 45-kt increase in intensity
over the next 36 h. The latest NHC intensity forecast thus was
increased over the next couple of days, and now peaks Kristy as a
110 kt category 3 hurricane in 60-72 h. It is worth noting that the
hurricane-regional model guidance mean is still a little above
that peak intensity. After 72 h, the same upper-level trough eroding
the subtropical ridge should also contribute to a rapid increase in
southwesterly vertical wind shear over Kristy as it also moves over
increasingly cool ocean waters. Thus, a fast rate of weakening is
likely to begin by this weekend, in good agreement with the IVCN and
HCCA consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT  22/1500Z 14.7N 106.6W   50 KT  60 MPH
12H  23/0000Z 14.6N 109.4W   60 KT  70 MPH
24H  23/1200Z 14.4N 112.6W   75 KT  85 MPH
36H  24/0000Z 14.3N 116.2W   90 KT 105 MPH
48H  24/1200Z 14.2N 119.4W  105 KT 120 MPH
60H  25/0000Z 14.3N 122.5W  110 KT 125 MPH
72H  25/1200Z 15.0N 125.2W  110 KT 125 MPH
96H  26/1200Z 18.0N 129.5W   80 KT  90 MPH
120H  27/1200Z 20.5N 133.5W   50 KT  60 MPH

$$
Forecaster Papin/Torres-Vazquez

ygsj24

000
WTPZ42 KNHC 222053
TCDEP2

Hurricane Kristy Discussion Number   5
NWS National Hurricane Center Miami FL       EP122024
200 PM MST Tue Oct 22 2024

Recent satellite and ASCAT data show Kristy has strengthened
significantly over the last six hours. Satellite imagery shows
persistent convection starting to wrap around a potential inner
core, with high-level cirrus clouds beginning to clear out,
revealing a developing eye. The ASCAT pass from 1618z showed a
robust wind field, with a max wind retrieval of 53 kt. The
subjective Dvorak intensity estimates also concur with these
observations, with T3.5/55 kt from TAFB and T4.0/65 kt from SAB at
18 UTC. Given the improvement on satellite since that time, the
initial intensity is now set at the upper-end of these estimates at
65 kt, making Kristy a hurricane.

Kristy continues to move just north of due west this afternoon as it
skirts along the periphery of a deep-layered subtropical
ridge. Current motion is set at 275/16 kt and this westward motion
should continue for the next couple of days. The cyclone will begin
to track poleward starting this weekend around 60-72 hours as a
mid-level trough impinges on the ridge. Uncertainty increases by
that time given differences in the global models as to the evolution
of the synoptic pattern.  As such, the latest NHC track forecast
remains close to the previous one over the next couple of days and
is just a little to the south of the previous forecast track
thereafter.

The intensity forecast remains quite bullish, with rapid
intensification expected within the next 12-24 hours as Kristy
encounters a very favorable environment as indicated by the GFS- and
ECMWF-SHIPS guidance. The latter aid also indicates a 40 percent
chance of a 40 kt increase in intensity in 24 hours, nearly ten
times the climatological average. The latest NHC forecast will
explicitly show Kristy intensifying up to 100 kt major hurricane
intensity in 24 h, with a peak intensity of 115 kt at 60 h. After
60-72 h, Kristy will encounter a more hostile environment, with
increasing shear and cooler sea surface temperatures which will
likely weaken the cyclone by the end of the forecast. Kristy is
likely to become post-tropical in 120 h as it loses convective
organization.


FORECAST POSITIONS AND MAX WINDS

INIT  22/2100Z 14.7N 108.5W   65 KT  75 MPH
12H  23/0600Z 14.6N 111.0W   85 KT 100 MPH
24H  23/1800Z 14.4N 114.5W  100 KT 115 MPH
36H  24/0600Z 14.2N 118.0W  105 KT 120 MPH
48H  24/1800Z 14.2N 121.0W  110 KT 125 MPH
60H  25/0600Z 14.7N 123.8W  115 KT 130 MPH
72H  25/1800Z 15.7N 126.5W  110 KT 125 MPH
96H  26/1800Z 18.7N 130.7W   70 KT  80 MPH
120H  27/1800Z 21.0N 134.5W   40 KT  45 MPH...POST-TROPICAL

$$
Forecaster Torres-Vazquez/Papin