瓦拉卡颶風巔峰照

開始轉北進行，15Z略微減弱到135節。

WTPA41 PHFO 021518
TCDCP1

Hurricane Walaka Discussion Number  12
NWS Central Pacific Hurricane Center Honolulu HI   CP012018
500 AM HST Tue Oct 02 2018

The satellite presentation of Walaka which was being degraded by an
eye wall replacement cycle overnight, has just begun to improve with
a ring of deep convection beginning to once again encircle the
well defined eye, which could be a sign that the eyewall replacement
cycle is getting ready to complete. The latest intensity estimates
from PHFO, SAB, JTWC were 6.5 (127 knots) while the ADT held at 6.6
(130 knots). Based on constraints likely holding the intensity of
Walaka too low Monday afternoon, have only reduced the initial
intensity slightly with this advisory to 135 knots. The initial
motion was set at 350/09 knots.

A deep north Pacific upper level low in the vicinity of 30N 170W
will draw Walaka northward over the next several days, before
another sharp upper trough shifting across the north Pacific picks
the tropical cyclone up and shifts it off to the northeast Friday
night and Saturday. Overall the guidance envelope remains fairly
tightly clustered through the forecast period. The official forecast
remains very close to that of the previous advisory and is fairly
well aligned with the latest GFEX, TVCN, HCCA consensus guidance.

The environment surrounding Walaka remains conducive for additional
intensification during the next 24 hours. The tropical cyclone will
remain within a deep moist airmass with low vertical wind shear,
high ocean heat content and sea surface temperatures between 84 to
86 Fahrenheit. Eyewall replacement cycles could lead to some
fluctuations in intensity through this time frame, so the intensity
forecast shows little intensity change through 24 hours. Beyond 24
hours, the combination of increasing vertical wind shear, drier
mid-level air entraining into the cyclone, sea surface temperatures
becoming marginal and even unfavorable, along with interaction with
the deep upper level low should result in steady and even rapid
weakening of Walaka. As a result, the intensity forecast calls for
Walaka to begin weakening on Wednesday, with rapid weakening then
continuing through the end of the forecast period. The official
intensity forecast was adjusted downward slightly, but remains above
all guidance through 36 hours before trending closer to a blend of
the statistical and dynamical models thereafter. Walaka is expected
to become an post-tropical/extra-tropical low by 120 hours.

The forecast track will take Walaka near Johnston Island later
today, with hurricane conditions expected this afternoon and this
evening. Therefore a Hurricane Warning remains in effect for this
location. The forecast track also takes the hurricane across the
Papahanaumokuakea Marine National Monument between French Frigate
Shoals and Laysan Island late Wednesday. Therefore, a Hurricane
Watch remains in effect for the region from Nihoa to Maro Reef.


FORECAST POSITIONS AND MAX WINDS

INIT  02/1500Z 14.7N 170.0W  135 KT 155 MPH
12H  03/0000Z 16.2N 170.2W  135 KT 155 MPH
24H  03/1200Z 18.9N 169.7W  135 KT 155 MPH
36H  04/0000Z 22.3N 168.4W  120 KT 140 MPH
48H  04/1200Z 26.2N 167.4W  100 KT 115 MPH
72H  05/1200Z 30.5N 168.0W   75 KT  85 MPH
96H  06/1200Z 33.0N 164.0W   60 KT  70 MPH
120H  07/1200Z 41.0N 157.5W   50 KT  60 MPH...POST-TROP/EXTRATROP

$$
Forecaster Jelsema

這個有實測的話 , 肯定比雷恩強






可能強度不輸伊歐佳, 或者瓦拉卡比伊歐佳稍強


路徑也有點像伊尼基.. 後期北上..

RAMMB給出140KTS，成為2006年IOKE後在中太土生土長的CAT 5，(LANE是東太跨界後在中太增強成CAT 5，所以不算)。

15Z評價110節，CPHC正式上望C5！

WTPA41 PHFO 011504
TCDCP1

Hurricane Walaka Discussion Number   8
NWS Central Pacific Hurricane Center Honolulu HI   CP012018
500 AM HST Mon Oct 01 2018

The satellite presentation of Walaka has improved significantly
overnight as the cyclone continues to rapidly intensify. The well
defined eye is surrounded by a large ring of -70 to -85C cloud
tops, and continues to show excellent outflow in all quadrants as
evident in geostationary satellite animations. Additionally, large
deep convective banding features are present on both the east and
west side of Walaka early this morning. The latest intensity
estimates came in at 5.5 (102 knots) from PHFO, SAB, and JTWC, while
the UW-CIMSS ADT was 5.4 (100 knots). As of 01/14Z, raw DT numbers
are as high as 7.0 (140 knots), but need to be held down
due to intensification constraints. Based on this data along with
the continued improvement in the appearance and organization, the
initial intensity of Walaka for this advisory was increased to 110
knots, making it 5 knots short of category 4 status. The initial
motion was set at 295/09 knots.

Walaka is beginning to round the southwest periphery of a large
subtropical ridge this morning and is currently moving toward the
west-northwest. A turn toward the northwest is expected later today
as a deep north Pacific upper trough digs southward in the vicinity
of 30N 170W and further erodes the western end of the subtropical
ridge. A turn toward the north is then expected on Tuesday, with
Walaka continuing on this course through Tuesday night with an
increase in forward speed. The tropical cyclone should then make a
turn toward the north-northeast Wednesday and Wednesday night as it
begins to feel the influence of the deep upper level trough. The
track guidance then suggests a shift back toward the north with a
decrease in forward speed Thursday through Friday as Walaka
interacts with the deep upper level trough, with a turn back toward
the northeast expected Friday night. The official track forecast
was changed very little from the previous advisory and remains
in close proximity to the tightly clustered HCCA, TVCN, and GFEX
consensus guidance.

The environment surrounding Walaka remains very conducive for
additional intensification during the next 36 hours and possibly
even a bit longer. Today through Tuesday, the tropical cyclone will
remain within a deep moist airmass, with vertical wind shear
forecast to remain around 10 knots, and sea surface temperatures
holding in the 84 to 86 Fahrenheit range. As a result, additional
rapid intensification is expected today into tonight, with the
cyclone then forecast to level off late tonight through Tuesday
night. Given the environment surrounding the system, the intensity
forecast brings Walaka up to category 5 intensity tonight, and is
slightly above the intensity guidance which doesn't explicitly
indicate Walaka will reach category 5 intensity. There is the
potential that Walaka could intensify even more than currently
forecast, but due to eyewall replacement cycles likely leading to
some fluctuation in intensity, the forecast was held nearly steady
from late tonight through Tuesday night. Vertical wind shear is
expected to steadily increase Wednesday and Wednesday night as
Walaka approaches and begins to interact with the deep upper level
trough over the north-central Pacific, with sea surface temperatures
dropping off during this time as well. The intensity forecast
calls for rapid weakening beginning beyond 48 hours, with this
weakening trend expected to continue through the end of the forecast
period. The official intensity forecast has been increased from the
previous advisory and is slightly higher than all intensity guidance
through 36 hours, then falls more closely in line with a blend of
the statistical and dynamical guidance for forecast hour 72 through
120.


FORECAST POSITIONS AND MAX WINDS

INIT  01/1500Z 12.3N 168.3W  110 KT 125 MPH
12H  02/0000Z 13.1N 169.4W  130 KT 150 MPH
24H  02/1200Z 14.5N 170.4W  140 KT 160 MPH
36H  03/0000Z 16.4N 170.7W  140 KT 160 MPH
48H  03/1200Z 18.9N 170.1W  135 KT 155 MPH
72H  04/1200Z 25.0N 167.5W  100 KT 115 MPH
96H  05/1200Z 29.5N 167.0W   75 KT  85 MPH
120H  06/1200Z 33.0N 164.0W   60 KT  70 MPH

$$
Forecaster Jelsema

隔壁棚的Walaka也進入RI，09Z評價90節，巔峰上望135節！

WTPA41 PHFO 010925
TCDCP1

Hurricane Walaka Discussion Number   7
NWS Central Pacific Hurricane Center Honolulu HI   CP012018
1100 PM HST Sun Sep 30 2018

Walaka is undergoing rapid intensification this evening, which is
clearly evident given the large ring of -70 to -85C cloud tops
surrounding the the well defined eye. Additionally, recent
microwave passes indicate that the organization of the system has
improved significantly, while geostationary satellite animations
show well defined outflow channels in all quadrants. The latest
intensity estimates came in at 5.0 (90 knots) from PHFO and SAB, 4.5
(77 knots) from JTWC, while the UW-CIMSS ADT was 4.2 (70 knots).
Based on the significant improvement in appearance and organization
of Walaka, the initial intensity for this advisory was increased to
90 knots. The initial motion was set at 280/10 knots.

Walaka continues to be steered westward this evening by a
subtropical ridge to the north of the system, and this motion is
expected to continue tonight. A turn toward the northwest is
expected on Monday as a deep north Pacific upper trough digs
southward in the vicinity of 30N 170W. A turn toward the north is
then expected on Tuesday, with Walaka continuing on this course
through Tuesday night with an increase in forward speed. The
tropical cyclone should then make a turn toward the north-northeast
Wednesday and Wednesday night as it begins to feel the influence of
the deep upper level trough. The track guidance then suggests a
shift back toward the north with a decrease in forward speed
Thursday through Friday as Walaka interacts with the deep upper
level trough. The official forecast was nudged slightly to the left
through 48 hours, then slightly to the right beyond 48 hours, and
is very close to the HCCA, TVCN, and GFEX consensus guidance.

The environment surrounding Walaka remains very conducive for
additional intensification through 48 hours. The tropical cyclone
will remain within a deep moist airmass, with vertical wind shear
forecast to remain around 10 knots or less through 48 hours, and
sea surface temperatures holding in the 84 to 86 Fahrenheit range
during this time. As a result, additional rapid intensification is
expected tonight and Monday, with the cyclone then forecast to level
off just below category 5 status Tuesday and Tuesday night. Given
the environment surrounding the system, intensification to a
category 5 storm is not out of the question, although none of the
intensity guidance explicitly indicate this at this time.
Additionally, Walaka will likely undergo eyewall replacement cycles
which will lead to some fluctuation in intensity. Beyond 48 hours,
vertical wind shear will steadily increase as Walaka approaches and
begins to interact with the deep upper level trough over the
north-central Pacific, with sea surface temperatures dropping off as
well. The intensity forecast shows a gradual weakening by 72 hours,
with rapid weakening then expected beyond 72 hours through the end
of the forecast period. The official intensity forecast has been
increased from the previous advisory and is in line with the high
end of the intensity guidance.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0900Z 11.9N 167.5W   90 KT 105 MPH
12H  01/1800Z 12.5N 168.7W  115 KT 130 MPH
24H  02/0600Z 13.5N 169.9W  130 KT 150 MPH
36H  02/1800Z 15.1N 170.5W  135 KT 155 MPH
48H  03/0600Z 17.2N 170.5W  135 KT 155 MPH
72H  04/0600Z 23.3N 168.1W  115 KT 130 MPH
96H  05/0600Z 28.5N 167.5W   75 KT  85 MPH
120H  06/0600Z 31.0N 166.0W   60 KT  70 MPH

$$
Forecaster Jelsema