Latest update (best part: We are no longer in "the cone"... but as the cone graphic says, hazards conditions can exist outside the cone):
000
WTPA42 PHFO 250255
TCDCP2
Hurricane Douglas Discussion Number 19
NWS Central Pacific Hurricane Center Honolulu HI EP082020
500 PM HST Fri Jul 24 2020
The eye of Douglas has remained visible in conventional satellite
imagery through the day today, and even cleared out for a little
while this afternoon, indicating that Douglas remains a powerful
hurricane. Subjective satellite current intensity estimates ranged
from 4.5/90 kt to 5.5/105 kt, while ADT was near 5.5. Although the
eye is clouding up again this afternoon, and surrounding convection
is cooling, the initial intensity has been held at 100 kt for this
advisory.
The forward motion vector has changed little over the past 24
hours, and is measured to be 295/17kt, as Douglas continues to be
steered by a mid-level ridge centered to the distant northeast.
As Douglas draws closer to the main Hawaiian Islands the next 2
days, it will round the western periphery of the ridge, allowing
the cyclone to gain some latitude, with some reduction in
forward speed. Thereafter, a mid-level ridge is forecast to
build to the north of Douglas, potentially inducing a turn
toward the west, with some increase in forward speed. The updated
track forecast is nearly identical to the previous, lies along the
southern side of a fairly tightly-clustered guidance envelope, and
is very close to ECMWF ensemble guidance. On the forecast track,
Douglas will move dangerously close to the Hawaiian Islands, and a
Hurricane Watch is posted for all islands except Kauai County, which
may need to be added on Saturday.
Douglas will be traversing an area of sub-26C SST for the next 36
hours or so, which is expected to lead a gradual weakening trend,
despite vertical wind shear on the lighter side, especially by
central Pacific standards. SSTs along the forecast track increase
from 48 hours onward, at the same time that Douglas is expected to
move into an area of increased vertical wind shear as it rounds the
southwestern periphery of an upper-level ridge. This is expected to
lead to a continued weakening trend, although at a fairly slow
rate. The intensity forecast is very close to the SHIPS guidance,
and close to the IVCN intensity consensus.
A Hurricane Hunter aircraft is en route to fly an initial mission
into Douglas, and this valuable data is expected to be available
for the next forecast update. Additional flights into Douglas are
scheduled for tomorrow. In the meantime, a morning ASCAT pass was
used to fine tune the wind radii analysis.
Key Messages
1. Douglas continues to approach the main Hawaiian Islands,
potentially passing dangerously close to, or over, the islands
Saturday night through Sunday night. The close passage of Douglas
brings a triple threat of hazards, including but not limited to
damaging winds, flooding rainfall, and dangerously high surf,
especially along east facing shores.
2. It is vital that you do not focus on the exact forecast track or
intensity of Douglas, and remain prepared for changes to the
forecast. Due to Douglas' angle of approach to the islands, any
small changes in the track could lead to significant differences in
where the worst weather occurs. Even if the center remains
offshore, severe impacts could still be realized over the islands,
as they extend well away from the center.
3. Terrain effects can cause strong localized acceleration of
the wind through gaps and where winds blow downslope. These
acceleration areas will shift with time as Douglas passes near the
islands. Winds will also be stronger at the upper floors of
high rise buildings.
FORECAST POSITIONS AND MAX WINDS
INIT 25/0300Z 17.9N 145.1W 100 KT 115 MPH
12H 25/1200Z 18.8N 147.5W 90 KT 105 MPH
24H 26/0000Z 20.0N 150.7W 80 KT 90 MPH
36H 26/1200Z 20.8N 153.5W 70 KT 80 MPH
48H 27/0000Z 21.4N 156.4W 65 KT 75 MPH
60H 27/1200Z 22.0N 159.4W 60 KT 70 MPH
72H 28/0000Z 22.6N 162.5W 55 KT 65 MPH
96H 29/0000Z 24.0N 169.5W 50 KT 60 MPH
120H 30/0000Z 25.0N 175.5W 45 KT 50 MPH
$$
Forecaster Birchard
https://www.nhc.noaa.gov/refresh/graphic...e#contents
000
WTPA42 PHFO 250255
TCDCP2
Hurricane Douglas Discussion Number 19
NWS Central Pacific Hurricane Center Honolulu HI EP082020
500 PM HST Fri Jul 24 2020
The eye of Douglas has remained visible in conventional satellite
imagery through the day today, and even cleared out for a little
while this afternoon, indicating that Douglas remains a powerful
hurricane. Subjective satellite current intensity estimates ranged
from 4.5/90 kt to 5.5/105 kt, while ADT was near 5.5. Although the
eye is clouding up again this afternoon, and surrounding convection
is cooling, the initial intensity has been held at 100 kt for this
advisory.
The forward motion vector has changed little over the past 24
hours, and is measured to be 295/17kt, as Douglas continues to be
steered by a mid-level ridge centered to the distant northeast.
As Douglas draws closer to the main Hawaiian Islands the next 2
days, it will round the western periphery of the ridge, allowing
the cyclone to gain some latitude, with some reduction in
forward speed. Thereafter, a mid-level ridge is forecast to
build to the north of Douglas, potentially inducing a turn
toward the west, with some increase in forward speed. The updated
track forecast is nearly identical to the previous, lies along the
southern side of a fairly tightly-clustered guidance envelope, and
is very close to ECMWF ensemble guidance. On the forecast track,
Douglas will move dangerously close to the Hawaiian Islands, and a
Hurricane Watch is posted for all islands except Kauai County, which
may need to be added on Saturday.
Douglas will be traversing an area of sub-26C SST for the next 36
hours or so, which is expected to lead a gradual weakening trend,
despite vertical wind shear on the lighter side, especially by
central Pacific standards. SSTs along the forecast track increase
from 48 hours onward, at the same time that Douglas is expected to
move into an area of increased vertical wind shear as it rounds the
southwestern periphery of an upper-level ridge. This is expected to
lead to a continued weakening trend, although at a fairly slow
rate. The intensity forecast is very close to the SHIPS guidance,
and close to the IVCN intensity consensus.
A Hurricane Hunter aircraft is en route to fly an initial mission
into Douglas, and this valuable data is expected to be available
for the next forecast update. Additional flights into Douglas are
scheduled for tomorrow. In the meantime, a morning ASCAT pass was
used to fine tune the wind radii analysis.
Key Messages
1. Douglas continues to approach the main Hawaiian Islands,
potentially passing dangerously close to, or over, the islands
Saturday night through Sunday night. The close passage of Douglas
brings a triple threat of hazards, including but not limited to
damaging winds, flooding rainfall, and dangerously high surf,
especially along east facing shores.
2. It is vital that you do not focus on the exact forecast track or
intensity of Douglas, and remain prepared for changes to the
forecast. Due to Douglas' angle of approach to the islands, any
small changes in the track could lead to significant differences in
where the worst weather occurs. Even if the center remains
offshore, severe impacts could still be realized over the islands,
as they extend well away from the center.
3. Terrain effects can cause strong localized acceleration of
the wind through gaps and where winds blow downslope. These
acceleration areas will shift with time as Douglas passes near the
islands. Winds will also be stronger at the upper floors of
high rise buildings.
FORECAST POSITIONS AND MAX WINDS
INIT 25/0300Z 17.9N 145.1W 100 KT 115 MPH
12H 25/1200Z 18.8N 147.5W 90 KT 105 MPH
24H 26/0000Z 20.0N 150.7W 80 KT 90 MPH
36H 26/1200Z 20.8N 153.5W 70 KT 80 MPH
48H 27/0000Z 21.4N 156.4W 65 KT 75 MPH
60H 27/1200Z 22.0N 159.4W 60 KT 70 MPH
72H 28/0000Z 22.6N 162.5W 55 KT 65 MPH
96H 29/0000Z 24.0N 169.5W 50 KT 60 MPH
120H 30/0000Z 25.0N 175.5W 45 KT 50 MPH
$$
Forecaster Birchard
https://www.nhc.noaa.gov/refresh/graphic...e#contents
