ATL: KIRK - Advisories

[cycloneye]

Hurricane Kirk Discussion Number 18
NWS National Hurricane Center Miami FL AL122024
500 PM AST Thu Oct 03 2024

Kirk continues to improve on satellite imagery, with a well-defined
circular eye. Infrared imagery depicts an inner core with cold tops
wrapping entirely around the eye, with lightning depicted on GLM
data in the northern eyewall. A recent GMI microwave pass also
depicts A tight inner core, and a vertically aligned structure of
the system. Subjective intensity estimates from TAFB and SAB
remained T5.5/102 kt. for this cycle. However, the UW-CIMMS
objective estimates and SATCON are a little higher and range from
110-124 kt Given the improved satellite depiction in recent hours
and a blend of these estimates, the initial intensity for this
advisory is set to 115 kt. Kirk is now a category 4 major hurricane
on Saffir-Simpson Hurricane Wind Scale.

The hurricane is moving northwestward at 315/10 kt. This motion
should continue over the next day or so as Kirk moves around the
edge of a subtropical ridge located over the eastern Atlantic. Kirk
will begin to curve and turn northeastward this weekend between an
approaching trough the eastern/central Atlantic and the subtropical
ridge. Models are tightly clustered and the latest NHC forecast
track is near the previous.

The system is embedded in a favorable environment with low vertical
wind shear and warm sea surface temperatures. Additional
strengthening is forecast over the next 24 h or so. Beyond 36 h,
wind shear is forecast to increase over the system and gradual
weakening is likely to occur. However, additional baroclinic energy
is likely to allow Kirk to maintain hurricane-force winds along with
a growing tropical-storm-force wind field through the end of the
forecast period. Global model fields depict the system becoming
extra-tropical by day 5. The NHC intensity forecast is near the
previous, with a higher peak intensity given the current initial
intensity.

Kirk is expected to grow in size and send out ocean swells across
the central and western Atlantic. These swells will likely increase
the risk of dangerous surf and rip currents along the Leeward
Islands by Friday, Bermuda and the Greater Antilles by Saturday, and
the U.S. East Coast and the Bahamas by Sunday.


FORECAST POSITIONS AND MAX WINDS

INIT 03/2100Z 21.1N 46.7W 115 KT 130 MPH
12H 04/0600Z 22.1N 47.8W 125 KT 145 MPH
24H 04/1800Z 23.7N 49.1W 125 KT 145 MPH
36H 05/0600Z 25.7N 50.1W 120 KT 140 MPH
48H 05/1800Z 28.4N 50.2W 110 KT 125 MPH
60H 06/0600Z 31.7N 49.3W 100 KT 115 MPH
72H 06/1800Z 35.2N 46.8W 90 KT 105 MPH
96H 07/1800Z 42.1N 36.9W 80 KT 90 MPH
120H 08/1800Z 46.4N 23.1W 65 KT 75 MPH...POST-TROP/EXTRATROP

$$
Forecaster Kelly

[cycloneye]

Hurricane Kirk Discussion Number 19
NWS National Hurricane Center Miami FL AL122024
1100 PM AST Thu Oct 03 2024

Kirk continues to prosper. The earlier eyewall replacement cycle
appears to have completed, and Kirk is back on a strengthening
trend. Satellite images indicate that Kirk has a circular and
clear 15 n mi eye surrounded by a solid ring of intense deep
convection. The latest satellite intensity estimates range from
115 to 135 kt, and based on that data, the initial wind speed is
increased to 125 kt.

The hurricane is moving northwestward at 9 kt, and this general
motion should continue through Friday as Kirk continues to move
along the southwestern periphery of a high pressure ridge over the
central and eastern subtropical Atlantic. A turn to the north is
expected on Saturday when Kirk reaches the western periphery of the
ridge and as a shortwave trough approaches the system. This trough
and a reinforcing one should cause the hurricane to accelerate
northeastward on Sunday and early next week. The models are in
fairly good agreement on this overall scenario, and the NHC track
forecast has been nudged westward to be in better agreement with
the latest model runs.

Kirk could strengthen a little more during the next 12 hours or so,
but increasing vertical wind shear and intrusions of dry air should
cause a steady weakening trend to begin shortly after that. Kirk
will likely complete extratropical transition when it moves
over cool waters sometime between day 4 and day 5, but it is
expected to remain a powerful system throughout the forecast
period. The NHC track forecast is in best agreement with the HCCA
and IVCN consensus models.

Even though Kirk is expected to stay over the open Atlantic, its
strong intensity and increasing size will cause large ocean swells
to propagate far away from the hurricane. These swells will likely
increase the risk of dangerous surf and rip currents across the
Leeward Islands beginning Friday, Bermuda and the Greater Antilles
by Saturday, and much of the U.S. East Coast, Atlantic Canada, and
the Bahamas by Sunday. For more information on this hazard, see
products issued by your local weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 04/0300Z 21.5N 47.5W 125 KT 145 MPH
12H 04/1200Z 22.5N 48.6W 135 KT 155 MPH
24H 05/0000Z 24.4N 49.7W 130 KT 150 MPH
36H 05/1200Z 26.8N 50.3W 120 KT 140 MPH
48H 06/0000Z 30.0N 49.9W 110 KT 125 MPH
60H 06/1200Z 33.6N 48.3W 100 KT 115 MPH
72H 07/0000Z 37.3N 44.7W 90 KT 105 MPH
96H 08/0000Z 43.5N 33.2W 75 KT 85 MPH
120H 09/0000Z 47.0N 16.8W 60 KT 70 MPH...POST-TROP/EXTRATROP

$$
Forecaster Cangialosi

[cycloneye]

Hurricane Kirk Discussion Number 20
NWS National Hurricane Center Miami FL AL122024
500 AM AST Fri Oct 04 2024

Kirk remains a large, powerful hurricane with an impressive
satellite presentation. The hurricane has a clear, circular 20 n mi-
wide eye that is surrounded by a ring of very deep convection.
The latest subjective Dvorak data-T numbers from TAFB and SAB are
T6.0/115 kt, while the various UW-CIMSS objective estimates are
around 125-130 kt. A blend of these values supports holding the
initial intensity at 125 kt. The wind radii of Kirk were made
slightly larger based on an earlier ASCAT overpass.

A subtropical high to the northeast of Kirk is steering the
hurricane northwestward (310/9 kt), but a northward turn is expected
on Saturday while the hurricane moves between the western extent of
the subtropical ridge and a shortwave trough approaching from the
west. Then, Kirk is forecast to accelerate northeastward into the
mid-latitudes on Sunday through early next week, ahead of a
deep-layer trough moving across the northern Atlantic. The track
guidance agrees on this recurvature scenario, and the NHC prediction
is very similar to the previous one with only slight left-of-track
adjustments to follow the multi-model consensus trends.

Satellite intensity estimates peaked overnight, and there is
evidence of some restriction of Kirk's upper-level outflow to the
west of the hurricane in recent satellite images. The shear is
expected to increase over Kirk during the next few days, along with
the potential for intrusions of dry air that could disrupt the
hurricane's convective organization. So while small short-term
intensity fluctuations are possible, the overall forecast trend is
for gradual weakening through Saturday, with more steady weakening
into early next week. As Kirk moves over cooler waters and into a
more baroclinic environment, it is expected to lose tropical
characteristics and transition to a strong extratropical cyclone by
96 h over the northeastern Atlantic. The NHC intensity forecast
closely follows the latest HCCA aid.

Even though Kirk is expected to recurve over the open Atlantic, its
strong intensity and increasing size will result in large ocean
swells that will propagate far away from the hurricane. These swells
will likely increase the risk of dangerous surf and rip currents
across the Leeward Islands beginning later today, Bermuda and the
Greater Antilles by Saturday, much of the U.S. East Coast, Atlantic
Canada, and the Bahamas by Sunday, and the Azores by Monday. For
more information on this hazard, see products issued by your local
weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 04/0900Z 22.3N 48.1W 125 KT 145 MPH
12H 04/1800Z 23.6N 49.2W 125 KT 145 MPH
24H 05/0600Z 25.7N 50.0W 125 KT 145 MPH
36H 05/1800Z 28.7N 50.1W 120 KT 140 MPH
48H 06/0600Z 32.3N 49.2W 105 KT 120 MPH
60H 06/1800Z 35.8N 46.7W 95 KT 110 MPH
72H 07/0600Z 39.8N 42.0W 85 KT 100 MPH
96H 08/0600Z 45.0N 29.0W 65 KT 75 MPH...POST-TROP/EXTRATROP
120H 09/0600Z 47.0N 14.5W 55 KT 65 MPH...POST-TROP/EXTRATROP

$$
Forecaster Reinhart

[cycloneye]

Hurricane Kirk Discussion Number 21
NWS National Hurricane Center Miami FL AL122024
1100 AM AST Fri Oct 04 2024

The satellite appearance of Kirk is a little less impressive than
it was six hours ago, as the eye has become somewhat cloud-filled
and the convective cloud tops have warmed a little. Recent
microwave imagery suggests that the hurricane may be starting an
eyewall replacement cycle, with an outer convective band wrapped
about three-quarters of the way around the eyewall. The various
objective and subjective satellite intensity estimates have trended
downward, and based on a combination of these estimates the initial
intensity is reduced to 120 kt. The wind radii have been tweaked
based on a recent ASCAT overpass.

The initial motion is 315/10. Kirk is currently approaching a large
break in the subtropical ridge caused by a deep-layer low centered
near 33N 60W. During the next 48-60 h, the hurricane should recurve
through this break and accelerate northeastward into the
mid-latitude westerlies. After that time, the cyclone should move
quickly east-northeastward across the northern and northeastern
Atlantic. There has been little change in the track guidance since
the previous advisory, and the new forecast track has only minor
adjustments from the previous track.

Fluctuations in intensity are likely during the next 24 h due to the
expected eyewall replacement cycle. After that, Kirk should
encounter increasing southwesterly shear and move over cooler sea
surface temperatures, which should cause a steady weakening.
Extratropical transition is likely to begin between 60-72 h and be
complete by 96 h, with Kirk becoming a strong extratropical cyclone
over the northeastern Atlantic. The new intensity forecast follows
the general trends of the intensity guidance, and is closest to the
GFS model during the extratropical stage.

Even though Kirk is expected to recurve over the open Atlantic, its
strong intensity and increasing size will result in large ocean
swells that will propagate far away from the hurricane. These swells
will likely increase the risk of dangerous surf and rip currents
across the Leeward Islands beginning later today, Bermuda and the
Greater Antilles by Saturday, much of the U.S. East Coast, Atlantic
Canada, and the Bahamas by Sunday, and the Azores by Monday. For
more information on this hazard, see products issued by your local
weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 04/1500Z 23.0N 48.9W 120 KT 140 MPH
12H 05/0000Z 24.4N 49.8W 115 KT 130 MPH
24H 05/1200Z 27.0N 50.3W 115 KT 130 MPH
36H 06/0000Z 30.3N 49.8W 110 KT 125 MPH
48H 06/1200Z 33.8N 48.3W 95 KT 110 MPH
60H 07/0000Z 37.6N 44.6W 85 KT 100 MPH
72H 07/1200Z 40.9N 39.3W 75 KT 85 MPH
96H 08/1200Z 45.3N 25.4W 55 KT 65 MPH...POST-TROP/EXTRATROP
120H 09/1200Z 48.0N 9.0W 50 KT 60 MPH...POST-TROP/EXTRATROP

$$
Forecaster Beven

[cycloneye]

Hurricane Kirk Discussion Number 22
NWS National Hurricane Center Miami FL AL122024
500 PM AST Fri Oct 04 2024

Kirk has changed little in structure during the past several hours
and remains an impressive hurricane with a well-defined eye inside
a central dense overcast. There has been no recent microwave
imagery to determine if the apparent outer eyewall seen earlier is
still there. The various subjective and objective satellite
intensity estimates are mostly near 115 kt, so the initial
intensity for this advisory is set at that.

The initial motion is now 325/10. Kirk is currently approaching a
large break in the subtropical ridge caused by a deep-layer low
centered near 33N 61W. During the next 48 h, the hurricane should
recurve through this break and accelerate northeastward into the
mid-latitude westerlies. After that time, the cyclone should move
quickly east-northeastward across the northern and northeastern
Atlantic. The track guidance more or less is the same as seen in
the previous advisory, with the exception of a southward nudge near
96 h. The new forecast track also has this nudge, but is otherwise
little changed from the previous track.

Fluctuations in intensity are likely during the next 12 h due to the
possible eyewall replacement cycle. After that, Kirk should
encounter increasing southwesterly shear and move over cooler sea
surface temperatures, which should cause a steady weakening.
Extratropical transition is likely to begin between 60-72 h and be
complete by 96 h, with Kirk becoming a strong extratropical cyclone
over the northeastern Atlantic. The new intensity forecast again
follows the general trends of the intensity guidance, and is closest
to the GFS model forecast during the extratropical stage.

Even though Kirk is expected to recurve over the open Atlantic, its
strong intensity and increasing size will result in large ocean
swells that will propagate far away from the hurricane. These swells
will likely increase the risk of dangerous surf and rip currents
across the Leeward Islands beginning this evening, Bermuda and the
Greater Antilles by Saturday, much of the U.S. East Coast, Atlantic
Canada, and the Bahamas by Sunday, and the Azores by Monday. For
more information on this hazard, see products issued by your local
weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 04/2100Z 23.7N 49.4W 115 KT 130 MPH
12H 05/0600Z 25.5N 50.0W 115 KT 130 MPH
24H 05/1800Z 28.5N 50.1W 110 KT 125 MPH
36H 06/0600Z 32.0N 49.1W 100 KT 115 MPH
48H 06/1800Z 35.6N 46.5W 90 KT 105 MPH
60H 07/0600Z 39.1N 42.0W 80 KT 90 MPH
72H 07/1800Z 42.0N 36.0W 70 KT 80 MPH
96H 08/1800Z 45.0N 19.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
120H 09/1800Z 49.5N 3.0W 45 KT 50 MPH...POST-TROP/EXTRATROP

$$
Forecaster Beven

[cycloneye]

Hurricane Kirk Discussion Number 23
NWS National Hurricane Center Miami FL AL122024
1100 PM AST Fri Oct 04 2024

Microwave images indicate that Kirk is going through another eyewall
replacement cycle. The inner eyewall is still closed while a larger
second eyewall wraps about 75 percent of the way around the eye and
inner eyewall. The satellite intensity estimates have held mostly
steady, and therefore, the initial intensity remains 115 kt.
Hurricanes that go through these eyewall replacement cycles often
get larger, and Kirk appears to be doing the same. The 34- and
50-kt wind radii have been expanded a little on the system's east
side based on a partial ASCAT-B pass.

Kirk is moving northwestward at 11 kt. A turn to the north is
expected on Saturday when Kirk reaches the western periphery of the
ridge, followed by a much faster northeastward and
east-northeastward motion Sunday and early next week when Kirk moves
in the strong mid-latitude flow. This track should take the core of
the system to the north of the Azores on Monday and then across
portions of western Europe by the middle of next week, Models are
in good agreement, and no significant changes were made to the
previous track forecast.

Fluctuations in intensity are likely in the short term, however, a
pronounced increase in shear, intrusions of drier air, and
progressively cooler waters should cause steady weakening beginning
on Saturday. Kirk is expected to become an extratropical cyclone by
day 3 when it is forecast to be over water temperatures in low 20's
C and embedded in the strong mid-latitude westerlies. The NHC
intensity forecast follows the trend in the model guidance, and is
in best agreement with the HCCA and IVCN consensus aids.

Even though Kirk is expected to recurve over the open Atlantic, its
strong intensity and increasing size will result in large ocean
swells that will propagate far away from the hurricane. These swells
will likely increase the risk of dangerous surf and rip currents
across the Leeward Islands, Bermuda, and the Greater Antilles
through Saturday, much of the U.S. East Coast, Atlantic Canada, and
the Bahamas by Sunday, and the Azores by Monday. For more
information on this hazard, see products issued by your local
weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 05/0300Z 25.0N 49.8W 115 KT 130 MPH
12H 05/1200Z 26.9N 50.2W 115 KT 130 MPH
24H 06/0000Z 30.2N 49.8W 105 KT 120 MPH
36H 06/1200Z 33.9N 48.1W 95 KT 110 MPH
48H 07/0000Z 37.7N 44.6W 85 KT 100 MPH
60H 07/1200Z 40.9N 39.4W 75 KT 85 MPH
72H 08/0000Z 43.2N 32.2W 65 KT 75 MPH...POST-TROP/EXTRATROP
96H 09/0000Z 45.4N 14.1W 55 KT 65 MPH...POST-TROP/EXTRATROP
120H 10/0000Z 50.6N 1.1W 45 KT 50 MPH...POST-TROP/EXTRATROP

$$
Forecaster Cangialosi

[cycloneye]

Hurricane Kirk Discussion Number 24
NWS National Hurricane Center Miami FL AL122024
500 AM AST Sat Oct 05 2024

The eye of Kirk has become ragged and cloud filled during the past
several hours. The satellite presentation suggests that
southwesterly shear and intrusions of dry air are negatively
affecting the hurricane, as a pronounced dry slot is noted on the
western side of Kirk. As a result of these structural changes, the
satellite intensity estimates have decreased overnight. Based on a
blend of the latest subjective Dvorak Current Intensity estimates
from TAFB and SAB with recent UW-CIMSS objective estimates, the
initial intensity is lowered to 110 kt.

Kirk continues to turn more northward (340/11 kt) within the flow
between a shortwave trough over the west-central Atlantic and a
subtropical ridge to the east of the hurricane. The track models
agree that Kirk should keep recurving to the northeast and
east-northeast through early next week while accelerating within
strong mid-latitude flow. The NHC forecast track shows the center of
Kirk passing to the north of the Azores on Monday as an
extratropical cyclone, and then moving across the northeastern
Atlantic and over western Europe by the middle of next week. No
significant changes were made to the updated NHC prediction.

The environmental conditions are expected to become increasingly
hostile over the coming days, with a marked increase in shear and a
drier environment surrounding the hurricane while it moves over
progressively cooler waters. Therefore, steady weakening is forecast
through early next week. Kirk should lose tropical characteristics
and transition to a strong extratropical cyclone between 60-72 h,
which is supported by the global model fields and simulated
satellite imagery. The updated NHC intensity forecast shows a
slightly faster rate of weakening, close to or slightly above the
latest HCCA aid. However, note that the wind field of the cyclone is
forecast to remain quite large through the 5-day forecast period.

Large and powerful Kirk is producing ocean swells that are
propagating far away from the hurricane. These large swells will
likely increase the risk of dangerous surf and rip currents across
the Leeward Islands, Bermuda, and the Greater Antilles beginning
later today, much of the U.S. East Coast, Atlantic Canada, and the
Bahamas by Sunday, and the Azores by Monday. For more information on
this hazard, see products issued by your local weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 05/0900Z 26.2N 50.2W 110 KT 125 MPH
12H 05/1800Z 28.4N 50.2W 105 KT 120 MPH
24H 06/0600Z 31.9N 49.2W 100 KT 115 MPH
36H 06/1800Z 35.7N 46.8W 85 KT 100 MPH
48H 07/0600Z 39.2N 42.6W 75 KT 85 MPH
60H 07/1800Z 42.0N 36.6W 70 KT 80 MPH
72H 08/0600Z 43.4N 28.8W 60 KT 70 MPH...POST-TROP/EXTRATROP
96H 09/0600Z 45.5N 10.5W 50 KT 60 MPH...POST-TROP/EXTRATROP
120H 10/0600Z 52.0N 4.5E 40 KT 45 MPH...POST-TROP/EXTRATROP

$$
Forecaster Reinhart

[cycloneye]

Hurricane Kirk Discussion Number 25
NWS National Hurricane Center Miami FL AL122024
1100 AM AST Sat Oct 05 2024

The inner core of Kirk has become a little less pronounced and
ragged on satellite imagery, with the eye becoming more cloud
filled. Shear is starting to increase over the system with some
drier air intrusions becoming evident. The latest subjective and
objective satellite intensity estimates have come down with this
cycle, and the initial intensity is lowered to 105 kt.

Kirk continues to turn more northward (355/14 kt) within the flow
between a shortwave trough over the west-central Atlantic and a
subtropical ridge to the east Atlantic Model guidance is in fairly
good agreement that Kirk should keep turning to the northeast and
east-northeast through early next week and increasing forward
motion. The NHC forecast track shows the center of Kirk passing to
the north of the Azores on Monday as an extratropical cyclone, and
then moving across the northeastern Atlantic and over western Europe
by the middle of next week. The official NHC track forecast is very
similar to the previous advisory.

The hurricane is getting ready to move into a hostile environment
with increasing shear and drier air. The system will also be
traversing cooler sea surface temperatures throughout the forecast
period. Therefore, steady weakening is forecast through early next
week. The system should lose tropical characteristics and
transition to a strong extratropical cyclone around 60 h, which is
supported by the global model fields and simulated satellite
imagery. The updated NHC intensity forecast is near the previous in
the near term, with a slightly faster rate of weakening beyond 60 h
in agreement with the latest HCCA and simple consensus aids.

Kirk is producing ocean swells that are propagating far away from
the hurricane. These large swells will likely increase the risk of
dangerous surf and rip currents across the Leeward Islands, Bermuda,
and the Greater Antilles beginning later today, much of the U.S.
East Coast, Atlantic Canada, and the Bahamas by Sunday, and the
Azores by Monday. For more information on this hazard, see products
issued by your local weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 05/1500Z 27.6N 50.3W 105 KT 120 MPH
12H 06/0000Z 30.1N 50.0W 100 KT 115 MPH
24H 06/1200Z 33.6N 48.5W 90 KT 105 MPH
36H 07/0000Z 37.1N 45.3W 85 KT 100 MPH
48H 07/1200Z 40.4N 40.2W 75 KT 85 MPH
60H 08/0000Z 42.5N 33.5W 65 KT 75 MPH...POST-TROP/EXTRATROP
72H 08/1200Z 43.5N 24.5W 55 KT 65 MPH...POST-TROP/EXTRATROP
96H 09/1200Z 47.2N 5.2W 50 KT 60 MPH...POST-TROP/EXTRATROP
120H 10/1200Z 54.9N 8.2E 40 KT 45 MPH...POST-TROP/EXTRATROP

$$
Forecaster Kelly

[cycloneye]

Hurricane Kirk Discussion Number 26
NWS National Hurricane Center Miami FL AL122024
500 PM AST Sat Oct 05 2024

Kirk continues to have a tight inner core, with deep convection
wrapping around the center. The eye has continued to become more
cloud filled, as shear increases over the system. The latest
subjective and objective satellite intensity estimates have held
mostly steady with this cycle, and the initial intensity is held at
105 kt.

Kirk continues to move northward and increase forward speed with an
estimated motion of (005/17 kt) between a trough located over the
west-central Atlantic and a subtropical ridge in the east Atlantic.
Model track guidance remains tightly clustered, although there has
been a slight shift southward as the system transitions and becomes
post-tropical. The NHC forecast track shows the center of Kirk
passing just to the north of the Azores on Monday as an
extratropical cyclone, and then moving across the northeastern
Atlantic and over western Europe by the middle of next week. The
official NHC track forecast is very similar to the previous
advisory, with a slight nudge southward towards the end of the
period following the consensus model trends.

Wind shear has started to increase over Kirk this afternoon, but the
inner core has been able to remain intact. However, the environment
will only continue to become more hostile as wind shear continues to
increase, with drier mid-level air, and cooler sea surface
temperatures. Therefore, steady weakening is forecast through early
next week. The system should lose tropical characteristics and
transition to a strong extratropical cyclone around 60 h. The
updated NHC intensity forecast is near the previous one in the near
term, with a slightly faster rate of weakening in agreement with the
latest HCCA and simple consensus aids.

Kirk is producing ocean swells that are propagating far away from
the hurricane. These large swells will likely increase the risk of
dangerous surf and rip currents across the Leeward Islands, Bermuda,
and the Greater Antilles beginning later today, much of the U.S.
East Coast, Atlantic Canada, and the Bahamas by Sunday, and the
Azores by Monday. For more information on this hazard, see products
issued by your local weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 05/2100Z 29.6N 50.0W 105 KT 120 MPH
12H 06/0600Z 32.1N 49.2W 95 KT 110 MPH
24H 06/1800Z 35.8N 47.0W 85 KT 100 MPH
36H 07/0600Z 39.2N 42.7W 75 KT 85 MPH
48H 07/1800Z 42.0N 36.9W 70 KT 80 MPH
60H 08/0600Z 43.5N 29.5W 60 KT 70 MPH...POST-TROP/EXTRATROP
72H 08/1800Z 44.3N 19.6W 50 KT 60 MPH...POST-TROP/EXTRATROP
96H 09/1800Z 47.7N .5W 45 KT 50 MPH...POST-TROP/EXTRATROP
120H 10/1800Z 55.8N 14.9E 30 KT 35 MPH...POST-TROP/EXTRATROP

$$
Forecaster Kelly

[cycloneye]

Hurricane Kirk Discussion Number 27
NWS National Hurricane Center Miami FL AL122024
1100 PM AST Sat Oct 05 2024

Kirk is gradually succumbing to the effects of increasing vertical
wind shear. Based on geostationary satellite imagery, the eye is
becoming more ragged and cloud-filled, and the southwestern quadrant
is wrapping in more dry air. Dvorak estimates have decreased this
cycle and the initial intensity is lowered to 100 kt, closest to the
TAFB estimate of 102 kt.

The hurricane is moving northward at 17 kt in the flow between a
deep-layer trough over the western Atlantic and a subtropical ridge
centered over the eastern Atlantic. Model guidance remains tightly
clustered, and very few changes have been made to the latest
official track forecast which lie close to the various consensus
aids. Kirk is expected to move north of the Azores on Monday and
move over western Europe Tuesday evening or Wednesday.

Atmospheric and oceanic conditions are expected to become less
conducive in the coming days. Vertical wind shear should become
quite strong later Sunday, and Kirk is expected to cross the 26
degree C isotherm Sunday evening. Global models predict Kirk to
become an extratropical cyclone on Tuesday and to then be absorbed
into a larger extratropical system later this week over northern
Europe. The latest NHC intensity forecast now reflects these
changes.

Kirk is producing ocean swells that are propagating far away from
the hurricane. These large swells have increased the risk of
dangerous surf and rip currents across the Leeward Islands, Bermuda,
and the Greater Antilles, the Bahamas, and portions of the U.S. East
Coast. By Sunday, swells are expected to spread northward along the
eastern seaboard and reach the Azores by Monday. For more
information on this hazard, see products issued by your local
weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 06/0300Z 31.3N 49.3W 100 KT 115 MPH
12H 06/1200Z 34.0N 48.1W 95 KT 110 MPH
24H 07/0000Z 37.6N 44.7W 85 KT 100 MPH
36H 07/1200Z 40.7N 39.7W 75 KT 85 MPH
48H 08/0000Z 42.8N 33.0W 65 KT 75 MPH...POST-TROP/EXTRATROP
60H 08/1200Z 43.7N 24.7W 55 KT 65 MPH...POST-TROP/EXTRATROP
72H 09/0000Z 44.1N 15.1W 50 KT 60 MPH...POST-TROP/EXTRATROP
96H 10/0000Z 49.5N 3.7E 40 KT 45 MPH...POST-TROP/EXTRATROP
120H 11/0000Z...DISSIPATED

$$
Forecaster Bucci

[cycloneye]

Hurricane Kirk Discussion Number 28
NWS National Hurricane Center Miami FL AL122024
500 AM AST Sun Oct 06 2024

Kirk continues to show the ill effects of increasing southwesterly
shear. Earlier scatterometer data and recent satellite images
suggest the hurricane is vertically tilted, with the low-level
center displaced to the southwest of the mid-level circulation. The
eye feature that was evident earlier today has filled, and satellite
intensity estimates are decreasing. Kirk's initial intensity is
estimated to be 90 kt, in best agreement with a T5.0 Dvorak Current
Intensity estimate from TAFB and recent UW-CIMSS D-MINT and D-PRINT
estimates. The wind radii of Kirk were made slightly larger based
on partial data from a 0014 UTC ASCAT-C overpass.

Kirk is expected to continue weakening during the next several days
due to the negative influences of increasing vertical wind shear,
decreasing SSTs, and a progressively drier mid-level environment.
However, the expansive wind field of Kirk should remain large while
the cyclone acquires frontal characteristics and transitions to an
extratropical cyclone by 48 h. It is possible that the hostile
conditions could cause Kirk to lose organized convection and become
post-tropical even sooner than forecast. The updated NHC intensity
forecast was adjusted downward to follow the latest HCCA and IVCN
consensus trends.

The hurricane is moving north-northeastward (015/20 kt) within the
flow between an eastern Atlantic subtropical ridge and a deep-layer
trough to the west of Kirk. The various track models agree that Kirk
will continue accelerating deeper into the mid-latitudes while
turning northeastward and east-northwestward over the next few days.
The NHC forecast is very similar to the previous prediction, showing
the center of Kirk passing north of the Azores Monday night into
Tuesday as an extratropical cyclone and moving over western Europe
during the middle of the week.

Large swells from Kirk are propagating far away from the hurricane
and bringing an increased risk of dangerous surf and rip currents to
portions of the Leeward Islands, the Greater Antilles, the Bahamas,
Bermuda, the U.S. East Coast, and Atlantic Canada. These swells are
expected to spread toward the Azores on Monday. For more information
on this hazard, see products issued by your local weather office.


FORECAST POSITIONS AND MAX WINDS

INIT 06/0900Z 33.5N 49.0W 90 KT 105 MPH
12H 06/1800Z 36.2N 47.0W 80 KT 90 MPH
24H 07/0600Z 39.6N 42.6W 70 KT 80 MPH
36H 07/1800Z 42.2N 36.7W 65 KT 75 MPH
48H 08/0600Z 43.4N 29.4W 55 KT 65 MPH...POST-TROP/EXTRATROP
60H 08/1800Z 43.9N 20.3W 50 KT 60 MPH...POST-TROP/EXTRATROP
72H 09/0600Z 45.5N 10.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
96H 10/0600Z 51.5N 7.5E 30 KT 35 MPH...POST-TROP/EXTRATROP
120H 11/0600Z...DISSIPATED

$$
Forecaster Reinhart

[cycloneye]

Hurricane Kirk Discussion Number 29
NWS National Hurricane Center Miami FL AL122024
1100 AM AST Sun Oct 06 2024

Most of Kirk's convection is now located in its northeastern
semicircle as a result of increasing southwesterly vertical wind
shear over the cyclone. Satellite intensity estimates continue to
decrease, with the latest subjective estimates from TAFB and SAB at
T-4.5/77 kt. Some of the objective CIMSS intensity estimates are
still a bit higher, and the initial intensity is set to 85 kt, in
agreement with the objective estimates.

Kirk is expected to continue to weaken during the next several days
due to strong southwesterly wind shear, which is expected to
increase even more after 24 h. Also, the hurricane will reach
cooler sea-surface temperature below 26C in about 12 hours. Global
models indicate that Kirk should undergo extratropical transition
soon, and the transition should be complete in about 36 h. Kirk's
wind field is expected to remain quite large, which will continue to
generate a very large area of dangerous seas over the Atlantic. The
NHC intensity forecast is similar to the previous prediction and
lies near the middle of the guidance.

Kirk is moving toward the north-northeast, or 020/22 kt within the
flow between an eastern Atlantic subtropical ridge and a deep-layer
trough to the west of Kirk. The track guidance continues to be in
fairly good agreement that Kirk will accelerate while turning
northeastward and east-northeastward over the next couple of days.
The NHC forecast is close to the previous prediction, and shows Kirk
passing north of the Azores Monday night and Tuesday as an
extratropical cyclone, then moving over portions of western Europe
Wednesday afternoon through Thursday.

Large swells from Kirk are propagating far away from the hurricane
and bringing an increased risk of dangerous surf and rip currents to
portions of the Leeward Islands, the Greater Antilles, the Bahamas,
Bermuda, the U.S. East Coast, and Atlantic Canada. These swells are
expected to spread toward the Azores on Monday. For more information
on this hazard, see products issued by your local weather office.

The initial wind radii have been increased based on data from a
recent ASCAT pass.


FORECAST POSITIONS AND MAX WINDS

INIT 06/1500Z 35.6N 47.7W 85 KT 100 MPH
12H 07/0000Z 38.1N 45.1W 75 KT 85 MPH
24H 07/1200Z 41.1N 39.9W 70 KT 80 MPH
36H 08/0000Z 43.1N 33.3W 60 KT 70 MPH...POST-TROP/EXTRATROP
48H 08/1200Z 43.8N 25.2W 55 KT 65 MPH...POST-TROP/EXTRATROP
60H 09/0000Z 44.5N 15.6W 50 KT 60 MPH...POST-TROP/EXTRATROP
72H 09/1200Z 46.7N 6.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
96H 10/1200Z 52.5N 9.0E 35 KT 40 MPH...POST-TROP/EXTRATROP
120H 11/1200Z...DISSIPATED

$$
Forecaster Hagen

[cycloneye]

Hurricane Kirk Discussion Number 31
NWS National Hurricane Center Miami FL AL122024
300 AM GMT Mon Oct 07 2024

Kirk is in the process of transitioning into an extratropical
cyclone. Satellite images show that the associated deep convection
is now confined to the northern side of the circulation and that the
inner core has been eroding. In addition, there appears to be some
frontal features beginning to form. The initial intensity is
lowered to 70 kt following a blend of the latest satellite intensity
estimates. The 34-kt wind radii have been tweaked on the system's
east side based on recent ASCAT data.

Extratropical transition should be complete on Monday when the
system moves over water temperatures in the low 20's C and into an
environment of nearly 40 kt of vertical wind shear. These
parameters will also cause steady weakening during the next few
days, and dissipation seems likely by day 4. The models are in
good agreement, and this forecast is closest to the latest GFS
solution.

Kirk is gradually turning to the right, and the latest initial
motion is 045/22 kt. A turn to the east-northeast with a notable
increase in forward speed is expected during the next few days as
the system moves within the mid-latitude westerly flow. This
should take the extratropical low to the north of the Azores on
Tuesday and across western Europe on Wednesday.

Although Kirk is over the open ocean, it is still producing large
swells that could lead to life-threatening rip currents across
portions of the Caribbean, Bermuda, the east coast of the U.S., and
Atlantic Canada.

FORECAST POSITIONS AND MAX WINDS

INIT 07/0300Z 38.6N 43.6W 70 KT 80 MPH
12H 07/1200Z 41.0N 39.7W 65 KT 75 MPH...POST-TROP/EXTRATROP
24H 08/0000Z 42.9N 33.4W 60 KT 70 MPH...POST-TROP/EXTRATROP
36H 08/1200Z 43.5N 25.7W 55 KT 65 MPH...POST-TROP/EXTRATROP
48H 09/0000Z 43.8N 16.2W 50 KT 60 MPH...POST-TROP/EXTRATROP
60H 09/1200Z 45.6N 6.3W 45 KT 50 MPH...POST-TROP/EXTRATROP
72H 10/0000Z 48.1N 3.7E 40 KT 45 MPH...POST-TROP/EXTRATROP
96H 11/0000Z...DISSIPATED

$$
Forecaster Cangialosi

[cycloneye]

Hurricane Kirk Discussion Number 32
NWS National Hurricane Center Miami FL AL122024
900 AM GMT Mon Oct 07 2024

Kirk has almost completed extratropical transition. The inner core
of the system has basically collapsed and deep convection is
limited to the northern half of the circulation. The system is
moving into a baroclinic zone, and it is expected to be an
extratropical cyclone later today. The initial intensity is nudged
downward to 65 kt based on a blend of the latest satellite
intensity estimates.

Strong shear, dry air, cool waters, and a decrease in upper-level
dynamics should cause Kirk to gradually lose strength. However, the
system's wind field will remain large and Kirk is still expected to
be a strong extratropical low during the next couple of days. The
intensity forecast is in good agreement with the latest GFS
solution.

Kirk is gradually turning to the right, and the latest initial
motion is 050/26 kt. A turn to the east-northeast with an
increase in forward speed is expected during the next couple of days
as the system moves within the fast mid-latitude westerly flow.
This should take the extratropical low to the north of the Azores on
Tuesday and across western Europe on Wednesday.

Although Kirk is over the open ocean, it is still producing large
swells that could lead to life-threatening rip currents across
portions of the Caribbean, Bermuda, the east coast of the U.S., and
Atlantic Canada.


FORECAST POSITIONS AND MAX WINDS

INIT 07/0900Z 40.2N 41.0W 65 KT 75 MPH
12H 07/1800Z 42.2N 36.8W 60 KT 70 MPH...POST-TROP/EXTRATROP
24H 08/0600Z 43.4N 29.9W 55 KT 65 MPH...POST-TROP/EXTRATROP
36H 08/1800Z 43.5N 21.1W 50 KT 60 MPH...POST-TROP/EXTRATROP
48H 09/0600Z 43.9N 11.5W 45 KT 50 MPH...POST-TROP/EXTRATROP
60H 09/1800Z 46.0N 2.1W 40 KT 45 MPH...POST-TROP/EXTRATROP
72H 10/0600Z...DISSIPATED

$$
Forecaster Cangialosi

[cycloneye]

BULLETIN
Post-Tropical Cyclone Kirk Advisory Number 33
NWS National Hurricane Center Miami FL AL122024
300 PM GMT Mon Oct 07 2024

...KIRK BECOMES A POWERFUL EXTRATROPICAL CYCLONE...
...STILL CAUSING LARGE SWELLS AND RIP CURRENT RISK ALONG THE U.S.
EAST COAST...


SUMMARY OF 300 PM GMT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...41.7N 38.4W
ABOUT 655 MI...1055 KM WNW OF THE AZORES
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...NE OR 45 DEGREES AT 29 MPH...46 KM/H
MINIMUM CENTRAL PRESSURE...963 MB...28.44 INCHES