墨西哥以西热带风暴“朱丽叶”(10E.Juliette)

ygsj24

984
WTPZ45 KNHC 270835
TCDEP5

Tropical Storm Juliette Discussion Number  11
NWS National Hurricane Center Miami FL       EP102025
200 AM PDT Wed Aug 27 2025

Juliette still has a relatively healthy presentation this morning on
satellite imagery, with a small, but symmetric area of deep
convection near its center. However, these cold cloud tops are
warming as the cyclone begins to move over the progressively cooler
ocean waters of the eastern North Pacific. Satellite intensity
estimates are decreasing, and we also received a helpful Metop-C
ASCAT pass at 0451 UTC which only had a peak wind retrieval of 36
kt in the eastern side of the tropical storm. The initial intensity
is only being lowered to 45 kt this advisory, assuming some
scatterometer undersampling of the small circulation.

The tropical storm is now moving north-northwestward, estimated at
330/11 kt. This motion should continue for the next day or so with a
little more rightward turn as Juliette is steered poleward through a
weakness in the mid-level ridging produced by a deep-layer trough
located off the California coast. As the cyclone becomes vertically
shallow, its forward motion should slow substantially as it becomes
more steered by the light and variable low-level flow in this part
of the eastern North Pacific. The official track forecast this cycle
is fairly similar to the prior one, other than a little more
eastward shift after Juliette becomes a remnant low. This forecast
remains generally in the middle of the guidance envelope.

Juliette's tropical cyclone story is fading as it moves over
sea-surface temperatures below 25C which cool further over the next
24 hours. While vertical wind shear is currently low, it is expected
to increase substantially after 24 hours, stripping away the storm's
remaining convection by that time. Thus, Juliette is expected to
become a remnant low in about 36 h. The remnant low should
ultimately open up into a trough by the end of the week.

Even as Juliette becomes a remnant low, some of its mid- to
upper-level moisture will be advected poleward towards portions of
northwestern Mexico and the southwestern U.S., which could help to
enhance local monsoonal rainfall for these areas in the latter half
of this week.


FORECAST POSITIONS AND MAX WINDS

INIT  27/0900Z 21.9N 118.8W   45 KT  50 MPH
12H  27/1800Z 23.3N 119.8W   40 KT  45 MPH
24H  28/0600Z 25.0N 120.6W   35 KT  40 MPH
36H  28/1800Z 26.3N 120.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
48H  29/0600Z 27.1N 120.8W   20 KT  25 MPH...POST-TROP/REMNT LOW
60H  29/1800Z 27.5N 121.0W   15 KT  15 MPH...POST-TROP/REMNT LOW
72H  30/0600Z...DISSIPATED

$$
Forecaster Papin

菜园子

FNV3 18Z （今天FNV3更新好像慢2小时）
EAGLE 00Z

pocketbox

全球热带气旋监测公报
预报：张怡驰、曹越男  签发：钱奇峰  2025 年 08 月 27 日 18 时
“朱丽叶”向西北方向移动

时        间:    27日14时（北京时，下同）

海        域:    东北太平洋

命        名:    “朱丽叶”，JULIETTE

中心位置:    西经118.5度, 北纬21.4度

强度等级:    热带风暴

最大风力:    9级，23米/秒，相当于我国的热带风暴级

中心气压:    1001百帕

参考位置:    距离墨西哥南下加利福尼亚州圣卢卡斯角西偏南方向约894公里

变化过程:    过去24小时，”朱丽叶”由10级减弱到9级

预报结论:    “朱丽叶”将以每小时20-25公里的速度向西北方向移动，强度逐渐减弱。



图1 卫星红外监测图像（北京时间2025年8月27日14时00分）

pocketbox

WTPZ45 KNHC 271435
TCDEP5

Tropical Storm Juliette Discussion Number  12
NWS National Hurricane Center Miami FL       EP102025
800 AM PDT Wed Aug 27 2025

Conventional satellite imagery this morning indicates that
Juliette's cloud pattern has begun to deteriorate.  Deep convection
has diminished in areal coverage while the cloud tops have warmed,
particularly over the surface center.  A blend of the subjective
Dvorak intensity estimates from TAFB and SAB (40-50 kt) and a
recent UW-CIMSS SATCON analysis of 48 kt yield an initial
intensity of 45 kt for this advisory.

Juliette is traversing a sharp sea surface temperature gradient
(less than 24 C) while moving into a drier, stable low- to
mid-tropospheric surrounding environment.  These negative
contributions, along with increasing west-southwesterly deep-layer
shear should weaken Juliette and cause the cyclone to become
a remnant low in 36 hrs, if not sooner.  Afterward, Juliette
should open into a trough by Friday.  The NHC intensity forecast is
based on the IVCN intensity consensus model and the LGEM.

The initial motion is estimated to be north-northwestward, or 330/11
kt. This motion should continue for the next couple of days followed
by a gradual northward turn on Thursday evening, while Juliette
moves further into a growing weakness in the mid-level subtropical
high.  As Juliette degenerates into a vertically shallow cyclone
toward the end of the period, a slower forward motion is expected
while being steered by the weaker low-level flow.  The official
track forecast is similar to the previous one and is close to the
various consensus aids.

Global models predict that residual mid- to upper-tropospheric
moisture will be advected toward portions of northwestern Mexico and
the southwestern U.S., potentially increasing humidity conditions
and enhancing local monsoonal rainfall toward the end of the week.


FORECAST POSITIONS AND MAX WINDS

INIT  27/1500Z 23.0N 119.5W   45 KT  50 MPH
12H  28/0000Z 24.4N 120.3W   40 KT  45 MPH
24H  28/1200Z 26.0N 120.6W   35 KT  40 MPH
36H  29/0000Z 27.1N 120.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
48H  29/1200Z 27.8N 120.6W   20 KT  25 MPH...POST-TROP/REMNT LOW
60H  30/0000Z...DISSIPATED

$$
Forecaster Roberts