北大西洋中部热带风暴“莱斯莉”(13L.Leslie) - 跟随Kirk西北行进，发展多次受阻，两度短暂开眼 - NHC MAX:90KT

qiqi

实时云图

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编扰资讯

AL, 91, 2024093018,   , BEST,   0, 101N,  241W,  25, 1008, DB

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2. Eastern Tropical Atlantic:
Showers and thunderstorms continue to increase in association with a
tropical wave located a few hundred miles south of the Cabo Verde
Islands.  Upper-level winds appear conducive for further
development, and a tropical depression is very likely to form in a
few days while it moves slowly westward over the eastern tropical
Atlantic.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 7 days...high...90 percent.

ygsj24

000
ABNT20 KNHC 302341
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Mon Sep 30 2024

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Depression Joyce, located over the central Atlantic Ocean, and on
Tropical Storm Kirk, located over the eastern Atlantic Ocean.

Northwestern Caribbean Sea and Gulf of Mexico:
Disorganized showers and thunderstorms located over the southwestern
Caribbean Sea are associated with a trough of low pressure.
Environmental conditions could support some gradual development of
this system, and a tropical depression could form over the next
several days while it moves generally northwestward over the
northwestern Caribbean Sea and the southern Gulf of Mexico.
Interests along the U.S. Gulf Coast should continue to monitor the
progress of this system.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...medium...40 percent.

Eastern Tropical Atlantic (AL91):
Satellite wind data indicate that a broad area of low pressure has
formed in association with a tropical wave located a few hundred
miles south of the Cabo Verde Islands. Showers and thunderstorms
continue to gradually increase in association with the system, and
environmental conditions appear conducive for further development. A
tropical depression is very likely to form during the next few days
while it moves slowly westward over the eastern tropical Atlantic.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 7 days...high...90 percent.

$$
Forecaster Reinhart

ygsj24

988
ABNT20 KNHC 011148
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Tue Oct 1 2024

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Kirk, located over the central tropical Atlantic Ocean.

Northwestern Caribbean Sea and Gulf of Mexico:
Disorganized showers and thunderstorms located over the southwestern
Caribbean Sea are associated with a trough of low pressure.
Environmental conditions could support some gradual development of
this system, and a tropical depression could form towards the end of
this week or this weekend while it moves generally northwestward
over the northwestern Caribbean Sea and into the Gulf of Mexico.
Interests along the U.S. Gulf Coast should continue to monitor the
progress of this system.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...medium...40 percent.

Eastern Tropical Atlantic (AL91):
Showers and thunderstorms continue to show signs organization in
association with a broad area of low pressure located a few hundred
miles south-southwest of the Cabo Verde Islands.  Environmental
conditions appear conducive for further development of this system,
and a tropical depression is expected to form during the next
couple of days while it moves slowly westward over the eastern
tropical Atlantic.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 7 days...high...90 percent.

$$
Forecaster Papin/Mora

pocketbox

SUBJ/TROPICAL CYCLONE FORMATION ALERT//
WTNT21 KNGU 011300
REF/A/FLTWEACEN NORFOLK VA/011300Z OCT 24//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTNT21 KNGU 011300)//
RMKS/1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 10.3N 25.0W TO 10.4N 28.8W
WITHIN THE NEXT 00 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 10 TO 15 KNOTS. METSAT
IMAGERY AT 011200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 10.2N 24.9W. THE SYSTEM IS MOVING WESTWARD AT 10 KNOTS.
2.REMARKS: SHOWERS AND THUNDERSTORMS SHOW SIGNS OF ORGANIZATION IN
ASSOCIATION WITH A BROAD AREA OF LOW PRESSURE LOCATED A FEW HUNDRED
MILES SOUTH-SOUTHWEST OF THE CABO VERDE ISLANDS. ENVIROMENTAL
CONDITIONS APPEAR FAVORABLE FOR FURTHER DEVELOPMENT DURING THE
NEXT COUPLE OF DAYS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1010 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH. THIS SUPERSEDES REF A.
MAXIMUM FORECAST SEAS OF 9 FT.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 021300Z.//

ygsj24

000
ABNT20 KNHC 011750
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Tue Oct 1 2024

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Kirk, located over the central tropical Atlantic Ocean.

Northwestern Caribbean Sea and Gulf of Mexico:
A broad trough of low pressure is producing a large area of
disorganized showers and thunderstorms from the southwestern
Caribbean Sea into the southern Gulf of Mexico. Environmental
conditions could support some gradual development of this system,
and a tropical depression could form towards the end of this week or
this weekend as the broader disturbance moves fully into the Gulf of
Mexico. Interests along the U.S. Gulf Coast should continue to
monitor the progress of this system.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...40 percent.

Eastern Tropical Atlantic (AL91):
Showers and thunderstorms continue to show signs organization in
association with an area of low pressure located a few hundred
miles south-southwest of the Cabo Verde Islands.  Environmental
conditions appear conducive for further development of this system,
and a tropical depression is expected to form during the next
day or two while it moves slowly westward over the eastern
tropical Atlantic.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 7 days...high...90 percent.

$$
Forecaster Papin/Mora

pocketbox

Special Message from NHC        Issued 2 Oct 2024 14:04 UTC   
NHC will initiate advisories on Tropical Depression Thirteen, located over the far eastern Tropical Atlantic, at 1100 AM AST (1500 UTC).

pocketbox

WTNT43 KNHC 021445
TCDAT3

Tropical Depression Thirteen Discussion Number   1
NWS National Hurricane Center Miami FL       AL132024
200 PM CVT Wed Oct 02 2024

The system we have been monitoring several hundred miles to the
southwest of the southernmost Cabo Verde Islands has become
gradually better organized this morning with some curved bands
organizing to the west of the estimated center. Visible satellite
images show that at least a broad closed circulation has developed.
Based on the latest subjective Dvorak fixes of T2.5/35-kt from TAFB
and T1.5/25-kt from SAB, advisories are being initiated on Tropical
Depression Thirteen, with an initial intensity in between these
estimates at 30 kt.

The depressions initial motion appears to be slowly due west, at
270/6 kt. Over the next day or two this motion should continue,
though some of the track guidance actually shows a south of due west
motion, partially related to the steering flow and also the
possibility that the center might try to reform underneath deep
convective bursts in the southern semicircle. After 48 h, the
guidance shows TD13 turning west-northwestward and then
northwestward by the end of the forecast as mid-level ridging
becomes more eroded on its northwestern side while a large long-wave
trough becomes established over the Northwest Atlantic. The initial
NHC track forecast has opted to favor a track close to the consensus
aid TVCN. Interestingly, both the GFS and ECMWF are on the east side
of the guidance, while HCCA is on the western side by the end of the
forecast period.

Intensity wise, initial strengthening could be on the slower end, as
the system has to deal with some northwesterly shear related of the
outflow from the much larger Hurricane Kirk impinging upon the
system. However, the guidance insists this shear will soon decrease,
especially after 24-36 h where the upper-level flow seems to split
off into a cutoff low to the southwest, and a upper-level trough
that shifts east of the depression, leaving the depression in a more
favorable upper-level diffluent pattern. After TD13's inner core
become better defined, the rate of intensification could increase
after 36 h, and the latest NHC intensity forecast forecasts the
depression to become a hurricane in 3 days. Additional
intensification is forecast after that point as long as the cyclone
tracks far enough away from the cold ocean wake left behind by Kirk.
This forecast is roughly in the mean of the intensity guidance
envelope.


FORECAST POSITIONS AND MAX WINDS

INIT  02/1500Z 10.6N  29.1W   30 KT  35 MPH
12H  03/0000Z 10.5N  29.8W   35 KT  40 MPH
24H  03/1200Z 10.2N  30.8W   40 KT  45 MPH
36H  04/0000Z 10.2N  31.9W   45 KT  50 MPH
48H  04/1200Z 10.4N  33.3W   55 KT  65 MPH
60H  05/0000Z 11.0N  34.6W   60 KT  70 MPH
72H  05/1200Z 11.7N  35.8W   65 KT  75 MPH
96H  06/1200Z 13.5N  38.1W   75 KT  85 MPH
120H  07/1200Z 16.5N  41.0W   80 KT  90 MPH

$$
Forecaster Papin

ygsj24

000
WTNT43 KNHC 022041
TCDAT3

Tropical Depression Thirteen Discussion Number   2
NWS National Hurricane Center Miami FL       AL132024
800 PM CVT Wed Oct 02 2024

Tropical Depression Thirteen has become a little better organized
since the last advisory, with improving circulation definition and
convection continuing to curve cyclonically in a banded fashion on
its western side. However, Dvorak intensity estimates have not
changed much this afternoon, still at T2.5/35-kt from TAFB and
T1.5/25-kt from SAB, so the initial intensity will remain 30 kt.

The depression appears to be moving just south of due west following
along from previous fixes with a current estimated motion at   260/7
kt. This motion has resulted in a slight southward track shift from
the previous forecast but remains close to the consensus aid TVCN.
This motion should continue over the next day or so guided by a
steering ridge to the north and enhanced convection along the
southern semicircle potentially pulling it southward as the
depression organizes. Track guidance then shows TD13 turning
west-northwestward after 48 hours and ultimately northwestward
towards the end of the forecast period as the ridge steering becomes
more eroded on its western side. The track guidance was very
similar to the previous cycle, albeit a touch further south in 5
days, and the latest NHC track has been nudged a bit further south
towards the end of the forecast.

The forecast for this cycle shows a somewhat faster intensification
rate than the prior advisory, with the system now becoming a
hurricane in 48 hours, and peaking at 80 kt in 72 hours, due to
decreasing shear and plenty of warm ocean waters and moisture early
on in the forecast. The intensity guidance then proceeds to show the
intensity plateauing after 72 hours as the system could encounter
the edge of Hurricane Kirk's large area of ocean upwelling. Both
HAFS-A/B show this potentially limiting the intensity in the longer
term, but the NHC intensity forecast could be conservative if TD13
ends up tracking further south than forecasted.


FORECAST POSITIONS AND MAX WINDS

INIT  02/2100Z 10.5N  29.7W   30 KT  35 MPH
12H  03/0600Z 10.2N  30.3W   35 KT  40 MPH
24H  03/1800Z 10.1N  31.3W   45 KT  50 MPH
36H  04/0600Z 10.2N  32.5W   55 KT  65 MPH
48H  04/1800Z 10.6N  33.8W   65 KT  75 MPH
60H  05/0600Z 11.1N  35.1W   75 KT  85 MPH
72H  05/1800Z 11.8N  36.4W   80 KT  90 MPH
96H  06/1800Z 13.8N  38.8W   80 KT  90 MPH
120H  07/1800Z 16.5N  42.0W   80 KT  90 MPH

$$
Forecaster Torres-Vazquez/Papin

ygsj24

000
WTNT43 KNHC 030237
TCDAT3

Tropical Storm Leslie Discussion Number   3
NWS National Hurricane Center Miami FL       AL132024
1100 PM AST Wed Oct 02 2024

Geostationary satellite and microwave images indicate that the
system has become better organized with convective bands wrapping
about two-thirds of the way around the center.  A partial ASCAT pass
from around 2230 UTC showed winds very close to tropical storm
force northeast of the center.  Since the system has continued to
become organized since the ASCAT pass, the initial intensity is
increased to 35 kt, making the cyclone Tropical Storm Leslie.   
This intensity estimate is also in agreement with a 2.5 Dvorak
classification from TAFB.

Leslie is moving slowly to the west at about 5 kt.  A continued slow
westward to west-northwestward motion is expected during the next 2
to 3 days as Leslie remains steered by a weak mid-level ridge to its
north.  Beyond that time, a slightly faster motion to the northwest
is predicted as the storm moves on the western periphery of the
ridge and approaches a broad trough over the central Atlantic.  The
models are in fair agreement overall, and the NHC track forecast
lies near the middle of the guidance envelope.

Leslie is currently in a moderate wind shear environment due to the
outflow from major Hurricane Kirk to its northwest.  However, the
shear is expected to lessen while Leslie remains over warm waters
and in a moist environment.  These condition should support steady
strengthening during the next few days, and the official intensity
forecast is a little higher than the previous one.  Beyond a few
days, Leslie is predicted to move over Kirk's prior track and
associated cool wake, and into a slightly drier air mass.  These
conditions could cause the intensity to level off.  The new
forecast is in best agreement with the latest HCCA guidance.


FORECAST POSITIONS AND MAX WINDS

INIT  03/0300Z 10.4N  30.1W   35 KT  40 MPH
12H  03/1200Z 10.2N  30.8W   40 KT  45 MPH
24H  04/0000Z 10.2N  31.9W   50 KT  60 MPH
36H  04/1200Z 10.4N  33.1W   60 KT  70 MPH
48H  05/0000Z 10.8N  34.5W   70 KT  80 MPH
60H  05/1200Z 11.4N  35.8W   80 KT  90 MPH
72H  06/0000Z 12.2N  37.0W   85 KT 100 MPH
96H  07/0000Z 14.3N  39.6W   85 KT 100 MPH
120H  08/0000Z 17.0N  42.9W   85 KT 100 MPH

$$
Forecaster Bucci/Cangialosi

renzhetegong

ECMWF系集反应很强，甚至控制报都预报918hPa

而GEFS的反应就相对较弱了