背风群岛以北五级飓风“温贝托”(08L.Humberto) - 西北行进，风眼开出，快速增强 - NHC:140KT

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WTNT43 KNHC 250839
TCDAT3

Tropical Storm Humberto Discussion Number   3
NWS National Hurricane Center Miami FL       AL082025
500 AM AST Thu Sep 25 2025

Humberto is still a shear tropical storm this morning.  Deep
convection is wrapped around the eastern side of the circulation
with the low-level center mostly exposed to the west of the coldest
cloud tops.  Objective and subjective satellite Dvorak
classifications have held steady this cycle, ranging from 33 to 41
kts.  The initial intensity remains at 40 kt based on the
scatterometer data mentioned in the previous discussion.

The estimated motion is northwestward at 9 kt.  Humberto is expected
to be steered along the southern and southwestern side of a
subtropical ridge centered over the western Atlantic.  The track
forecast becomes more complicated in the next few days due to the
proximity of the tropical storm to 94L, the developing system to the
west.  Global models generally show Humberto moving around the
western periphery of the subtropical high by the end of the forecast
period, however there is quite a bit of uncertainty in the timing
and location at which the storm will make that turn.  The GFS and
UKMet show a much faster and farther east track while the ECMWF
predicts a slower and more westward track.  The latest official
track forecast is slower and a bit west of the previous prediction,
near the center of the guidance envelope.

Humberto is expected to gradually strengthen during the next couple
of days, despite the strong-to-moderate vertical wind shear.  When
the westerly shear relaxes over the storm in 2-3 days, more
signification intensification is expected over the warm ocean
waters.  Most model guidance predicts Humberto will reach hurricane
strength over the weekend and become a major hurricane by early next
week. Few changes have been made to the NHC intensity forecast,
which still lies near the FSU Superensemble prediction.


FORECAST POSITIONS AND MAX WINDS

INIT  25/0900Z 21.2N  56.4W   40 KT  45 MPH
12H  25/1800Z 21.7N  57.0W   45 KT  50 MPH
24H  26/0600Z 22.1N  57.6W   50 KT  60 MPH
36H  26/1800Z 22.6N  58.4W   55 KT  65 MPH
48H  27/0600Z 23.0N  59.4W   60 KT  70 MPH
60H  27/1800Z 23.5N  61.0W   75 KT  85 MPH
72H  28/0600Z 24.3N  63.0W   90 KT 105 MPH
96H  29/0600Z 26.7N  66.8W  100 KT 115 MPH
120H  30/0600Z 30.6N  69.3W   95 KT 110 MPH

$$
Forecaster Bucci

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全球热带气旋监测公报
预报：徐立、刘涛  签发：王海平  2025 年 09 月 25 日 18 时
“温贝托”向西偏北方向移动

时        间:   25日14时

海        域:    北大西洋

命        名:    “温贝托”，HUMBERTO

中心位置:    西经56.2度，北纬21.0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:    1007百帕

参考位置:    距离北大西洋开曼群岛东北方向约780公里

变化过程:    过去12小时，“温贝托”强度维持8级

预报结论:   “温贝托”将以每小时18公里左右的速度向西偏北方向移动，强度逐渐增强。



图3 卫星红外监测图像（北京时间2025年9月25日14时00分）

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WTNT43 KNHC 251438
TCDAT3

Tropical Storm Humberto Discussion Number   4
NWS National Hurricane Center Miami FL       AL082025
1100 AM AST Thu Sep 25 2025

Deep convection has been increasing near and to the east of the
center of Humberto during the past several hours, but the storm
remains asymmetric due to the effects of wind shear and dry air
entertainment.  The initial intensity is increased a little to 45
kt, which is near the high end of the latest satellite estimates.

The tropical storm is expected to continue to battle shear and dry
air associated with a nearby mid- to upper-level trough for another
day or so.  However, by the weekend, the models show the upper-level
wind pattern becoming notably more favorable for strengthening.
Based on the current trends and expected conducive conditions, the
NHC intensity forecast has been nudged upward and shows Humberto
becoming a hurricane in a day or so and then rapidly strengthening
to a major hurricane over the weekend.  This prediction is roughly
in line with the latest HCCA and IVCN consensus models.

Humberto is currently embedded in weak steering currents on the
south side of a narrow and weak subtropical high over the central
Atlantic.  This pattern should keep the storm moving slowly to the
west-northwest or northwest during the next day or two.  After that
time, Humberto is expected to become primarily steered by a much
stronger high over the western Atlantic, which should cause the
storm to speed up.  The models have trended south and west this
cycle, and the NHC track forecast has been nudged in those
directions.  This forecast keeps Humberto over the open central
and western subtropical Atlantic during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT  25/1500Z 21.4N  56.8W   45 KT  50 MPH
12H  26/0000Z 21.8N  57.3W   50 KT  60 MPH
24H  26/1200Z 22.1N  57.9W   55 KT  65 MPH
36H  27/0000Z 22.4N  58.8W   65 KT  75 MPH
48H  27/1200Z 22.8N  60.1W   75 KT  85 MPH
60H  28/0000Z 23.4N  61.9W   90 KT 105 MPH
72H  28/1200Z 24.2N  64.0W  105 KT 120 MPH
96H  29/1200Z 27.0N  67.8W  105 KT 120 MPH
120H  30/1200Z 30.7N  69.7W   95 KT 110 MPH

$$
Forecaster Cangialosi

ygsj24

019
WTNT43 KNHC 252037
TCDAT3

Tropical Storm Humberto Discussion Number   5
NWS National Hurricane Center Miami FL       AL082025
500 PM AST Thu Sep 25 2025

Humberto continues to gradually gain strength over the central
Atlantic.  Deep convection has been increasing over the center, and
the cloud pattern is more symmetric than it was earlier today.  This
is an indication that the wind shear around the storm is lessening.
Recent microwave images indicate that an inner core appears to be
forming, and an earlier ASCAT pass showed maximum winds of about 45
kt.  Based on the improving satellite presentation, the initial
intensity is increased to 50 kt.  This value is also near the
average of the latest satellite intensity estimates.  The 34-kt wind
radii have been adjusted based on the ASCAT data.

Steady to rapid strengthening is expected during the next few days
as the storm moves into a more favorable environment of light winds
aloft and high moisture.  Given that Humberto is relatively compact
and an increasingly symmetric system, these conditions should cause
it to become a hurricane on Friday and a major hurricane over the
weekend. Less favorable environmental conditions should cause some
weakening early next week.  This prediction remains in line with the
latest HCCA and IVCN consensus models.

The storm has jogged a little to the north today, but the overall
motion is northwestward at 5 kt. Humberto remains embedded in weak
steering currents on the south side of a narrow and weak subtropical
high over the central Atlantic.  This pattern should keep the storm
moving slowly to the west-northwest or northwest during the next day
or two.  After that time, Humberto is expected to become
increasingly steered by a much stronger high over the western
Atlantic, which should cause the storm to accelerate.  The NHC track
forecast is a little slower than the previous one, trending toward
the latest consensus and Google Deep Mind models. This forecast
keeps Humberto over the open central and western subtropical
Atlantic during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT  25/2100Z 21.9N  57.0W   50 KT  60 MPH
12H  26/0600Z 22.3N  57.4W   60 KT  70 MPH
24H  26/1800Z 22.5N  58.0W   70 KT  80 MPH
36H  27/0600Z 22.7N  59.1W   80 KT  90 MPH
48H  27/1800Z 23.0N  60.8W   90 KT 105 MPH
60H  28/0600Z 23.6N  62.7W  100 KT 115 MPH
72H  28/1800Z 24.6N  64.7W  105 KT 120 MPH
96H  29/1800Z 28.0N  68.2W  105 KT 120 MPH
120H  30/1800Z 31.6N  69.9W   90 KT 105 MPH

$$
Forecaster Cangialosi

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全球热带气旋监测公报
预报：钟晖子、刘涛  签发：吕心艳  2025 年 09 月 26 日 10 时
“温贝托”向西北方向移动

时        间:   26日08时

海        域:    北大西洋

命        名:    “温贝托”，HUMBERTO

中心位置:    西经57.0度，北纬22.1度

强度等级:    热带风暴

最大风力:    10级，28米/秒，相当于我国的强热带风暴级

中心气压:    997百帕

参考位置:    距离北大西洋开曼群岛东北方向约770公里

变化过程:    过去24小时，“温贝托”强度由8级加强为10级

预报结论:   “温贝托”将以每小时10公里左右的速度向西北方向移动，强度逐渐增强。



图2 卫星红外监测图像（北京时间2025年9月26日08时00分）

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WTNT43 KNHC 260241
TCDAT3

Tropical Storm Humberto Discussion Number   6
NWS National Hurricane Center Miami FL       AL082025
1100 PM AST Thu Sep 25 2025

Humberto continues to gain strength while moving slowly over the
central Atlantic.  The system is exhibiting a growing CDO feature
with cloud tops to near -70 deg C, along with some convective bands
over the eastern portion of the circulation, where most of the
lightning flashes are currently occurring.  The advisory intensity
is increased to 55 kt, in agreement with subjective Dvorak
classifications from both TAFB and SAB and a blend of objective
satellite estimates from UW-CIMSS.

The storm's forward speed is quite slow with a motion estimate of
only 320/3 kt.  Steering currents are not strong at this time since
the subtropical ridge to the north of Humberto is quite weak.  
Global model forecasts show the ridge strengthening with time and in
a few days the cyclone should move somewhat faster toward the  
northwest and turn northward in the vicinity of 70 W longitude. By
the end of the forecast period, after Humberto passes north of the
ridge, the system should begin accelerating northeastward.

Cirrus motions indicate that the vertical wind shear over Humberto
has lessened, and the SHIPS model output does not show the shear
increasing much through 72 hours.  Sea surface temperatures are
expected to be very warm along the projected path of the cyclone,
and the system should remain embedded in a moist air mass.  The
official forecast continues to call for significant strengthening
during the next few days.  This is consistent with the latest
corrected consensus, HCCA, forecast which also shows Humberto
intensifying into a major hurricane this weekend.


FORECAST POSITIONS AND MAX WINDS

INIT  26/0300Z 22.2N  57.1W   55 KT  65 MPH
12H  26/1200Z 22.4N  57.6W   65 KT  75 MPH
24H  27/0000Z 22.7N  58.5W   75 KT  85 MPH
36H  27/1200Z 22.9N  59.9W   90 KT 105 MPH
48H  28/0000Z 23.4N  61.8W  105 KT 120 MPH
60H  28/1200Z 24.3N  63.8W  110 KT 125 MPH
72H  29/0000Z 25.4N  65.7W  110 KT 125 MPH
96H  30/0000Z 29.0N  69.0W  100 KT 115 MPH
120H  01/0000Z 32.6N  69.7W   90 KT 105 MPH

$$
Forecaster Pasch

觀雲趣

AMSR 89GHz
又一槽爆的

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全球热带气旋监测公报
预报：钟晖子、刘涛  签发：张玲  2025 年 09 月 26 日 18 时
“温贝托”向西北方向移动

时        间:   26日14时

海        域:    北大西洋

命        名:    “温贝托”，HUMBERTO

中心位置:    西经57.1度，北纬22.1度

强度等级:    热带风暴

最大风力:    10级，28米/秒，相当于我国的强热带风暴级

中心气压:    998百帕

参考位置:    距离北大西洋开曼群岛东北方向约770公里

变化过程:    过去24小时，“温贝托”强度由8级加强为10级

预报结论:   “温贝托”将以每小时5-10公里的速度向西北方向移动，强度逐渐增强。



图2 卫星红外监测图像（北京时间2025年9月26日14时00分）

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WTNT43 KNHC 260843
TCDAT3

Hurricane Humberto Discussion Number   7
NWS National Hurricane Center Miami FL       AL082025
500 AM AST Fri Sep 26 2025

Humberto has become better organized during the past several hours.
Conventional satellite imagery has shown a growing central dense
overcast, with hints of an eye-like feature near the center.
Microwave imagery revealed a well-defined rain band wrapping around
a vertically-aligned vortex, suggesting the developing of an
eyewall.  Satellite classifications have risen notably on this
cycle and the initial intensity is set to 65 kt, closest to the
TAFB Dvorak and SATCON estimates.

The hurricane is drifting slowly in weak steering currents with an
estimated motion of 320/3 kt.  Model guidance is in relatively good
agreement, showing Humberto gradually increasing speed while moving
west-northward to northwestward along the southern side of a
subtropical ridge during the next few days.  By early next week, the
hurricane is expected to turn northward around the westward
periphery of the high and begin accelerating northeastward.  Only
minor adjustments have been made to the latest official track
forecast.

Humberto is showing signs of steady-to-rapid intensification.  The
hurricane is over warm waters and seems to be experiencing less
vertical wind shear than the global models are currently suggesting.
Statistical rapid intensity indicators, such as DTOPS, are showing
elevated probabilities of a 25 to 30 kt increase in the next 24
hours.  Given these probabilities and the recent increase in initial
intensity, the NHC intensity forecast has been increased,
particularly in the near-term forecast, and lies above most of the
guidance.  By the middle of the forecast period, it is closer the
the corrected consensus aid, HCCA, and still shows Humberto becoming
a major hurricane this weekend.


FORECAST POSITIONS AND MAX WINDS

INIT  26/0900Z 22.2N  57.3W   65 KT  75 MPH
12H  26/1800Z 22.3N  57.8W   80 KT  90 MPH
24H  27/0600Z 22.6N  59.0W   90 KT 105 MPH
36H  27/1800Z 22.9N  60.5W  100 KT 115 MPH
48H  28/0600Z 23.5N  62.5W  110 KT 125 MPH
60H  28/1800Z 24.5N  64.2W  115 KT 130 MPH
72H  29/0600Z 26.0N  66.0W  115 KT 130 MPH
96H  30/0600Z 29.7N  68.8W  100 KT 115 MPH
120H  01/0600Z 33.7N  67.8W   85 KT 100 MPH

$$
Forecaster Bucci

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WTNT43 KNHC 261447
TCDAT3

Hurricane Humberto Discussion Number   8
NWS National Hurricane Center Miami FL       AL082025
1100 AM AST Fri Sep 26 2025

Humberto continues to rapidly strengthen this morning. Infrared
satellite images show a ring of deep, cold inner core convection
wrapping around an eye that has recently emerged in conventional
satellite imagery. Objective satellite intensity estimates are
quickly climbing, and the initial intensity is raised to 80 kt for
this advisory, in best agreement with recent UW-CIMSS ADT and AiDT
estimates. A recent ASCAT-B pass over the hurricane was used to
update the 34- and 50-kt wind radii of Humberto.

The rapidly improving satellite structure, along with conducive
environmental and oceanic conditions, suggest that significant to
rapid intensification (RI) is likely to continue in the short term.
In fact, the latest DTOPS guidance shows a greater than 80 percent
chance of Humberto strengthening by 30 kt in the next 24 h. Thus,
rapid intensification is explicitly forecast here, and the NHC
intensity forecast has been raised during the first 48-72 h of the
forecast period. This forecast most closely follows the regional
hurricane models and the HFIP corrected consensus (HCCA), on the
higher end of the guidance envelope. By early next week, there are
indications that deep-layer shear will increase over Humberto, and
some weakening is shown beyond 72 h. Note that as Humberto gains
latitude, the wind field is forecast to expand while the hurricane
curves around Bermuda at days 4-5.

The hurricane is moving slowly northwestward at about 4 kt.
Humberto should move toward the west-northwest and northwest during
the next couple of days along the southern periphery of a
subtropical ridge over the western and central Atlantic. As this
ridge slides eastward, the hurricane is forecast to recurve around
this feature, turning northward and then accelerating northeastward
early next week. The models are in very good agreement on this
sharp recurvature over the western Atlantic, and only minor
adjustments were made to the latest NHC track forecast.


FORECAST POSITIONS AND MAX WINDS

INIT  26/1500Z 22.3N  57.7W   80 KT  90 MPH
12H  27/0000Z 22.5N  58.3W   95 KT 110 MPH
24H  27/1200Z 22.9N  59.6W  105 KT 120 MPH
36H  28/0000Z 23.3N  61.3W  115 KT 130 MPH
48H  28/1200Z 24.1N  63.3W  125 KT 145 MPH
60H  29/0000Z 25.3N  65.2W  125 KT 145 MPH
72H  29/1200Z 26.8N  66.9W  120 KT 140 MPH
96H  30/1200Z 30.6N  68.8W  105 KT 120 MPH
120H  01/1200Z 34.5N  66.0W   90 KT 105 MPH

$$
Forecaster Reinhart