EPAC: KARINA - Post-Tropical

[Yellow Evan]

EP, 11, 2014081600, , BEST, 0, 177N, 1215W, 45, 1000, TS, 34, NEQ, 50, 40, 40, 50, 1008, 160, 30, 0, 0, E, 0, , 0, 0, KARINA, M,

[cycloneye]

TROPICAL STORM KARINA DISCUSSION NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014
800 PM PDT FRI AUG 15 2014

The convective pattern of Karina continues to deteriorate, with the
coverage of cold cloud tops decreasing during the past few hours.
The low-level center is partially exposed on the northeastern edge
of the convective canopy due to about 15 kt of easterly shear. A
blend of the latest Dvorak CI numbers from TAFB and SAB yields an
initial intensity estimate of 40 kt. Little change in strength is
expected during the forecast period. The vertical shear is expected
to decrease a little by day 3, but the cyclone will be moving over
somewhat cooler SSTs by then. The NHC intensity forecast is close to
the IVCN intensity consensus through the period.

The initial motion estimate is 280/09, as Karina is being steered
by a subtropical ridge to the north. This ridge will build westward
during the next couple of days, followed by an amplification of a
ridge well north of the Hawaiian Islands, which should result in
Karina's track bending a little south of due west during the middle
of the forecast period. By day 5, the ridging north of Karina will
weaken as a mid/upper-level trough amplifies off the west coast of
North America. This should result in a collapse of the steering
currents and a slow and perhaps erratic motion by the end of the
period. The NHC track forecast is largely an update of the previous
one and is close to the TVCE multi-model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT 16/0300Z 17.8N 122.0W 40 KT 45 MPH
12H 16/1200Z 18.1N 123.6W 40 KT 45 MPH
24H 17/0000Z 18.2N 125.6W 40 KT 45 MPH
36H 17/1200Z 18.1N 127.6W 40 KT 45 MPH
48H 18/0000Z 17.8N 129.4W 40 KT 45 MPH
72H 19/0000Z 17.2N 132.5W 45 KT 50 MPH
96H 20/0000Z 17.0N 134.0W 45 KT 50 MPH
120H 21/0000Z 17.0N 134.5W 45 KT 50 MPH

$$
Forecaster Brennan

[hurricanes1234]

Karina did not do so well...

[cycloneye]

TROPICAL STORM KARINA DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014
200 AM PDT SAT AUG 16 2014

Karina continues to be affected by about 15 kt of easterly vertical
wind shear, with the low-level center located just to the northeast
of a burst of convection with cloud tops colder than -80C.
Satellite intensity estimates are 45 kt from TAFB and 35 kt from
SAB. In addition, a recent ASCAT overpass showed 35-40 kt winds
about 40 n mi north of the center. Based on these data, the initial
intensity remains 40 kt.

The initial motion is now 285/9, with Karina continuing to be
steered by a subtropical ridge to the north. This ridge will build
westward during the next couple of days, followed by an
amplification of a ridge well north of the Hawaiian Islands. These
developments should result in Karina turning westward later today
and then turning a little south of due west during the middle of the
forecast period. The steering current are expected to collapse after
72 hours as a mid/upper-level trough likely develops off the west
coast of North America and other areas of disturbed weather develop
east and west of the cyclone. During this time, the GFS and
Canadian models forecast a loop back to the east, the ECMWF and
UKMET models forecast a slow westward motion, and the NAVGEM and GFS
ensemble mean forecast a slow northward motion. The official
forecast track compromises between these forecasts by showing a
westward drift. Overall, the new track is again similar to the old
track and near the multi-model consensus.

The large-scale models forecast the shear to decrease during the
next 48 hours or so. However, Karina will be moving over gradually
decreasing sea surface temperatures, and the forecast track keeps
the center near the 26C isotherm after 48 hours. In the short
term, Karina is expected to weaken a little more. While the
official forecast keeps the system as a tropical storm, an
alternate scenario is shown by the SHIPS and LGEM models, which
forecast it to weaken to a depression. After 48 hours, the
guidance suggests Karina could re-intensify if it is not absorbed
by one of the nearby disturbances. The latter part of the official
forecast reflects this by showing modest strengthening.

FORECAST POSITIONS AND MAX WINDS

INIT 16/0900Z 18.1N 122.9W 40 KT 45 MPH
12H 16/1800Z 18.2N 124.4W 35 KT 40 MPH
24H 17/0600Z 18.2N 126.4W 35 KT 40 MPH
36H 17/1800Z 18.0N 128.4W 35 KT 40 MPH
48H 18/0600Z 17.6N 130.1W 35 KT 40 MPH
72H 19/0600Z 16.5N 132.5W 40 KT 45 MPH
96H 20/0600Z 16.5N 133.5W 40 KT 45 MPH
120H 21/0600Z 16.5N 134.0W 45 KT 50 MPH

$$
Forecaster Beven

[Equilibrium]

http://einstein.atmos.colostate.edu/~mc ... 8_diag.dat
HWRF intensify at 80 hrs

[hurricanes1234]

Karina is not doing well. I would be surprised if this restrengthens any significant bit, although it does look a little better to me on the latest frame. I'd personally estimate the chances of a major are <2-3% and the chances of a hurricane again are <40-50%.

[Yellow Evan]

EP, 11, 2014081612, , BEST, 0, 183N, 1236W, 40, 1002, TS, 34, NEQ, 60, 40, 40, 50, 1008, 160, 30, 0, 0, E, 0, , 0, 0, KARINA, M,

[cycloneye]

TROPICAL STORM KARINA DISCUSSION NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014
800 AM PDT SAT AUG 16 2014

The center of Karina is located on the northeastern edge of a
circular area of very deep convection due to moderate easterly
vertical wind shear. Satellite intensity estimates from TAFB and SAB
continue to support an initial intensity of 40 knots. Most of the
global guidance as well as the SHIPS model indicate that the shear
will persist for the next 24 to 36 hours while a portion of the
circulation is over relatively cooler waters. On this basis, the NHC
forecast indicate some slight weakening during the next day or so.
After that time, the shear could relax some and the cyclone
will likely turn west-southwestward toward warmer waters. This
should result in some intensification as suggested by the intensity
consensus. HWRF is the most aggressive model forecasting Karina back
to hurricane status.

It appears that the expected amplification of the ridge to the north
of Karina is already materializing, and the cyclone is now moving
toward the west or 270 degrees at 9 knots. The ridge will continue
to build westward as indicated by global models, and this pattern
will force the cyclone to move toward the west-southwest for the
next 3 days or so. By then, the steering currents are expected to
collapse when several disturbances develop nearby. This will likely
cause Karina to meander for the remainder of the forecast
period. Track guidance has not change and continues to support
both the west-southwest track and the decrease in forward speed
indicated by NHC, which in fact, is very close to the multi-model
consensus.


FORECAST POSITIONS AND MAX WINDS

INIT 16/1500Z 18.3N 124.1W 40 KT 45 MPH
12H 17/0000Z 18.4N 125.7W 35 KT 40 MPH
24H 17/1200Z 18.3N 127.6W 35 KT 40 MPH
36H 18/0000Z 17.8N 129.5W 35 KT 40 MPH
48H 18/1200Z 17.5N 131.0W 40 KT 45 MPH
72H 19/1200Z 16.5N 133.0W 40 KT 45 MPH
96H 20/1200Z 16.5N 134.0W 45 KT 50 MPH
120H 21/1200Z 16.8N 134.3W 50 KT 60 MPH

$$
Forecaster Avila

[Yellow Evan]

EP, 11, 2014081618, , BEST, 0, 180N, 1245W, 40, 1002, TS, 34, NEQ, 60, 40, 40, 50, 1008, 160, 30, 0, 0, E, 0, , 0, 0, KARINA, M,

[Yellow Evan]

000
WTPZ41 KNHC 162038
TCDEP1

TROPICAL STORM KARINA DISCUSSION NUMBER 16
NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014
200 PM PDT SAT AUG 16 2014

The cloud pattern has continued to deteriorate today, with the
low-level center now removed from the deep convection due to
moderate easterly shear. T-numbers have decreased to T2.0 and T2.5
on the Dvorak scale, and a recent partial ASCAT pass shows maximum
winds of 35 knots. On this basis, the intensity has been set at 35
knots. Although Karina has weakened, it most likely will begin to
re-strengthen in about 24 hours when the circulation moves over
warmer waters and into weaker shear. In fact, the HWRF insists on
bringing Karina back to hurricane status in 3 days. The NHC forecast
is not that aggressive and brings the winds only to 50 knots in
agreement with the intensity consensus.

Microwave and conventional fixes indicate that the center has been
moving just south of due west or 260 degrees at 10 knots. The ridge
to the north of Karina is expected to amplify a little more forcing
the cyclone to move on a west-southwest track for the next 2 to 3
days. After that time, the steering currents are expected to
collapse due to the development of several disturbances nearby, and
that pattern will keep the cyclone meandering for the remainder
of the forecast period. Most of the dynamical track guidance
forecast a sharp but slow turn to the right before Karina arrives at
132 degrees longitude. Given the weak steering flow, the NHC
forecast shows little movement between 3 and 5 days.

FORECAST POSITIONS AND MAX WINDS

INIT 16/2100Z 17.9N 125.0W 35 KT 40 MPH
12H 17/0600Z 17.7N 126.4W 35 KT 40 MPH
24H 17/1800Z 17.5N 128.4W 40 KT 45 MPH
36H 18/0600Z 17.0N 129.8W 40 KT 45 MPH
48H 18/1800Z 16.5N 131.0W 45 KT 50 MPH
72H 19/1800Z 16.0N 132.0W 50 KT 60 MPH
96H 20/1800Z 15.5N 132.0W 50 KT 60 MPH
120H 21/1800Z 15.5N 132.0W 50 KT 60 MPH

$$
Forecaster Avila

[hurricanes1234]

Totally sheared in my opinion. I won't be surprised to see a depression soon.

[Yellow Evan]

EP, 11, 2014081700, , BEST, 0, 178N, 1256W, 35, 1003, TS, 34, NEQ, 60, 0, 30, 50, 1008, 120, 50, 45, 0, E, 0, , 0, 0, KARINA, M, 12, NEQ, 100, 50, 60, 110,

[cycloneye]

TROPICAL STORM KARINA DISCUSSION NUMBER 17
NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014
800 PM PDT SAT AUG 16 2014

The low-level center of Karina was exposed to the east of the deep
convection in the last-light visible images, consistent with the
nearly 15 kt of shear analyzed by UW-CIMSS. Overall, the cloud
pattern remains relatively unimpressive, with little banding and a
general decrease in the cold convective tops during the past few
hours. The initial intensity remains 35 kt based on the latest
Dvorak estimate from SAB. Little change in intensity is expected
during the next 24 hours, but some re-strengthening is forecast
after that time as SSTs along the forecast track begin to increase a
little. The NHC intensity forecast is similar to the previous one
and is near or a bit above the IVCN intensity consensus.

The latest satellite fixes yield an initial motion estimate of
260/10. Karina will continue moving westward to west-southwestward
for the next couple of days as the cyclone is steered by a
subtropical ridge to the north. After that time, the steering
currents weaken as the ridge erodes and the global models show other
tropical cyclones possibly forming east and west of Karina. Little
net motion is expected after 48 hours, and confidence in the details
of the track forecast beyond that time is lower than normal. The new
NHC track forecast is close to the previous one, but a little faster
in the first 36 to 48 hours.

FORECAST POSITIONS AND MAX WINDS

INIT 17/0300Z 17.8N 126.1W 35 KT 40 MPH
12H 17/1200Z 17.5N 127.5W 35 KT 40 MPH
24H 18/0000Z 17.1N 129.3W 35 KT 40 MPH
36H 18/1200Z 16.6N 130.9W 40 KT 45 MPH
48H 19/0000Z 16.0N 132.1W 45 KT 50 MPH
72H 20/0000Z 16.0N 132.5W 50 KT 60 MPH
96H 21/0000Z 16.0N 133.0W 50 KT 60 MPH
120H 22/0000Z 16.0N 133.0W 50 KT 60 MPH

$$
Forecaster Brennan

[Equilibrium]

Thinking maybe Karina will re-intensify to a Cat 2 over the next couple of days.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

[Yellow Evan]

Thinking maybe Karina will re-intensify to a Cat 2 over the next couple of days.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

I'd go with a Cat 1. Interaction with 91E should delay intensification a bit. System a bit like Paine/Roslyn 92.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[xtyphooncyclonex]

Could this pull another Genevieve? TBH it is possible, conditions are quite similar...

[Yellow Evan]

Could this pull another Genevieve? TBH it is possible, conditions are quite similar...

Idk. Storms like Genevieve are very rare.

[cycloneye]

TROPICAL STORM KARINA DISCUSSION NUMBER 18
NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014
200 AM PDT SUN AUG 17 2014

Although Karina is producing a little more deep convection than it
was earlier this evening, the system has a sheared appearance with
the low-level center located near the eastern edge of the deep
cloudiness. A pair of ASCAT passes around 0600 UTC showed maximum
winds of around 35 kt to the west of the center, therefore, the
initial intensity is held at that value. This wind speed estimate
is also in fair agreement with Dvorak T-numbers from TAFB, SAB, and
UW-CIMSS ADT. Only slight strengthening is forecast as the
environmental conditions are not expected to change much during the
next several days, with the shear predicted to remain moderate and
sea surface temperatures marginal. The NHC intensity forecast is
slightly lower than the previous one to be closer to the latest
guidance.

Karina is moving just south of due west at about 9 kt. A west to
southwest motion is forecast during the next 2 to 3 days while the
storm remains steered by the subtropical ridge to the north of the
system. Beyond that time, the cyclone is likely to stall or move
erratically when the steering currents significantly weaken in
response to developing tropical disturbances both to the west
and east of Karina. Although a considerable amount of spread in
the models exist, they do agree on this general scenario. The NHC
track forecast lies fairly close to the multi-model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT 17/0900Z 17.9N 127.0W 35 KT 40 MPH
12H 17/1800Z 17.6N 128.2W 35 KT 40 MPH
24H 18/0600Z 17.1N 130.0W 40 KT 45 MPH
36H 18/1800Z 16.4N 131.4W 40 KT 45 MPH
48H 19/0600Z 16.1N 132.2W 45 KT 50 MPH
72H 20/0600Z 16.1N 133.0W 45 KT 50 MPH
96H 21/0600Z 16.1N 133.5W 45 KT 50 MPH
120H 22/0600Z 16.1N 133.5W 45 KT 50 MPH

$$
Forecaster Cangialosi

[hurricanes1234]

Intensification is lowered in the latest forecast. With conditions not that good, I'd say there is a slight chance it only weakens from here.

[cycloneye]

TROPICAL STORM KARINA DISCUSSION NUMBER 19
NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014
800 AM PDT SUN AUG 17 2014

There has been little change to Karina's convective organization
since the previous advisory. A large mass of deep convection with
cloud tops to near -80C remains sheared to the west and southwest
of the partially exposed low-level circulation center due to
moderate easterly vertical wind shear. The intensity was increased
slightly to 40 kt based on ASCAT data that arrived after the
previous advisory had been issued, which showed reliable 38-39 kt
wind vectors to the west of the low-level center.

Karina has been moving due west or 270/10 kt over the past 6 hours.
There is no significant change to previous forecast track or
prognostic reasoning. Karina is expected to gradually make a turn
toward the west-southwest over the next 24 hours, and then
maintain that motion accompanied by a decrease in forward speed
through 72 hours as a large ridge to the north of the Hawaiian
Island builds southward to the west of the cyclone. After that, the
large disturbance located about 700 nmi east of Karina is expected
to develop and become a very large circulation, more than than
twice the normal size of a tropical cyclone. That system is
forecast to dominate the steering flow across much of the eastern
North Pacific, producing a long fetch of low- to mid-level
southwesterly flow that is expected to gradually steer Karina back
toward the east and northeast on Days 4 and 5. It is possible
that Karina could stall on Day 3 when steering currents briefly
collapse. The NHC forecast track is similar to the previous advisory
track and closely follows the consensus model TVCE.

The GFS-based SHIPS intensity guidance shows only 7 kt of easterly
850-200 mb wind shear currently affecting Karina, an analysis that
appears to be too weak given the large westward displacement of the
deep convection. In contrast, UW-CIMSS shear analyses indicate about
15 kt of easterly mid-level shear is affecting the cyclone, which
likely better explains the very asymmetric convective cloud pattern.
The overall shear pattern is not forecast to change much for the
next 5 days, so little change in strength is expected during that
time, especially since Karina will be over or near marginal SSTs of
26-26.5C throughout the forecast period. The official intensity
forecast is just an update of the previous advisory, and closely
follows the ICON intensity consensus model.

FORECAST POSITIONS AND MAX WINDS

INIT 17/1500Z 18.0N 128.2W 40 KT 45 MPH
12H 18/0000Z 17.6N 129.5W 40 KT 45 MPH
24H 18/1200Z 16.9N 131.2W 45 KT 50 MPH
36H 19/0000Z 16.4N 132.4W 45 KT 50 MPH
48H 19/1200Z 16.2N 133.1W 50 KT 60 MPH
72H 20/1200Z 16.2N 133.8W 45 KT 50 MPH
96H 21/1200Z 16.4N 134.1W 45 KT 50 MPH
120H 22/1200Z 16.6N 133.3W 45 KT 50 MPH

$$
Forecaster Stewart