EPAC: CELIA - Post-Tropical

[Alyono]

noticed one error in the NHC discussion. They mentioned the cold wake would cease to have an effect after about 72-96 hours. However, this is why you CANNOT merely look at a static SST field. The 120 hour position is very near the path of Blas. Thus, the cold wake may affect Blas up through the day 7 position.

This is why I am confident there is not likely to be a threat to HI from this system. Not to mention, this is becoming significantly less organized

[wxman57]

Current Four-E position is about 120 miles south of Blas' track, but the two tracks converge around day 6.

[cycloneye]

This discussion talks a lot about the Blas cold wake.

TROPICAL DEPRESSION FOUR-E DISCUSSION NUMBER 4
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016
900 AM MDT THU JUL 07 2016

Tropical Depression Four-E has not improved in organization since
the last advisory. A small cluster of deep convection is located
near the low-level center, but otherwise widespread showers and
thunderstorms mainly within the eastern and southern portion of the
circulation are lacking banding characteristics. The intensity
remains 30 kt based on Current Intensity estimates of 2.0 from TAFB
and SAB.

The cyclone is still moving west-northwestward, or 285/7 kt. A
strong subtropical ridge, which extends from northern Mexico
westward to near 130W, is expected to maintain its strength and
remain stationary for at least the next 3 days. This pattern is
forecast to drive the depression almost due westward between 24
and 72 hours. By days 4 and 5, the ridge is expected to weaken a
bit, which should allow the cyclone to gain some latitude and turn
back toward the west-northwest. The track models, particularly the
GFS and ECMWF, are very tightly clustered, with those two models
less than a degree apart at day 5. The updated NHC track forecast
was nudged southward on days 4 and 5 to be closer to the GFS/ECMWF
consensus, but otherwise there is higher-than-normal confidence in
the track forecast for the entire 5-day period.

The key concern for the depression's intensity forecast is the cold
wake left behind by Hurricane Blas. Based on the latest available
daily global SST analyses, the waters ahead of the depression have
cooled to 26.5 degrees Celsius or colder. The official forecast
track for the depression intersects and remains very close to Blas's
track during the next 5 days, which would keep it over these
colder-than-normal waters for a significant amount of time.
Since the SHIPS guidance utilizes a weekly SST analysis, which is
showing ocean surface temperatures about 2 degrees too warm,
confidence in its output is somewhat low at the moment. Vertical
shear and environmental moisture values appear conducive for
strengthening, so the NHC official intensity forecast still shows
intensification, but at a slower rate than indicated by many of the
intensity models. The updated forecast is also a little lower than
the previous one, especially through 48 hours.

FORECAST POSITIONS AND MAX WINDS

INIT 07/1500Z 12.7N 110.8W 30 KT 35 MPH
12H 08/0000Z 13.0N 111.9W 35 KT 40 MPH
24H 08/1200Z 13.2N 113.5W 40 KT 45 MPH
36H 09/0000Z 13.2N 115.2W 45 KT 50 MPH
48H 09/1200Z 13.2N 117.0W 55 KT 65 MPH
72H 10/1200Z 13.2N 120.6W 75 KT 85 MPH
96H 11/1200Z 14.0N 124.5W 85 KT 100 MPH
120H 12/1200Z 16.0N 128.5W 90 KT 105 MPH

$$
Forecaster Berg

[Kingarabian]

I don't know if you folks remember Hurricane Blanca from last season. It was forecast to become a cat.5 and it was well on its way of doing so until it became stationary. After becoming stationary it weakened because it upwelled the waters under it significantly.

The HWRF showed this nicely:
[/quote]

The HWRF and the GFDL are showing the cooler waters resulting from Blas's cool wake but they dont look to be significantly deterring:
GFDL:

HWRF:

[cycloneye]

 https://twitter.com/RyanMaue/status/751088308021628928

[Alyono]

Maue is not even considering the cold wake. The EC solution is not meaningful as it is not a coupled model

[Kingarabian]

Looks like the track taking Celia close or over Hawaii is independent of the track Blas takes.

Euro and GFS are in general agreeement and they both have completely different handles on the track Blas takes.

[Yellow Evan]

All he was doing was just pointing out how strong the 12z ECMWF makes it. He didn't say it would/wouldn't reach such strength.

Thinking this tops 100-105 knots, given the cold wake doesn't look too bad (26-27C waters), of which the storm will pass just south of, and that shear is low. Not sure how this sort of SST gradient will affect the inner core of this future system, so confidence is low.

[cycloneye]

TROPICAL DEPRESSION FOUR-E DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016
300 PM MDT THU JUL 07 2016

Recent ASCAT data indicate that the tropical depression has an
elongated circulation and is still producing maximum winds around
30 kt. Although deep convection has been increasing in coverage
during the day, it is not all that organized and is primarily
confined to the eastern and southern semicircles. In addition, dry
air appears to be wrapping into the western part of the
circulation. Since the cyclone's structure has not yet improved,
and the system is about to move over the cold wake of Hurricane
Blas, it may take a little more time before significant
strengthening can occur. In fact, the GFS and ECMWF models, which
should have a good handle on the ambient environment, do not show
significant deepening of the cyclone for another 48 hours or so.
Therefore, the NHC official intensity forecast has been adjusted
downward during the first couple of days, with the depression
possibly not becoming a tropical storm until tomorrow. More
significant strengthening is expected after 48 hours, but even that
could be tempered by interaction with Blas's cold wake. The NHC
intensity forecast is at the low end of the guidance through 48
hours and then near the IVCN intensity consensus thereafter.

The scatterometer data showed that the low-level center is located
a little farther south than previously estimated, and the initial
motion is now 275/7 kt. A strong mid-tropospheric ridge extending
westward from northern Mexico is forecast to keep the cyclone on a
westward course for the next 3 days. By days 4 and 5, the ridge is
expected to weaken a bit, which will allow the cyclone to turn
west-northwestward. The NHC official track forecast was shifted
slightly southward during the first three days to account for the
updated initial position. Otherwise, the guidance remains tightly
clustered, and there is high confidence in the track forecast.

FORECAST POSITIONS AND MAX WINDS

INIT 07/2100Z 12.4N 111.7W 30 KT 35 MPH
12H 08/0600Z 12.6N 112.8W 30 KT 35 MPH
24H 08/1800Z 12.9N 114.4W 35 KT 40 MPH
36H 09/0600Z 13.0N 116.1W 40 KT 45 MPH
48H 09/1800Z 13.1N 118.0W 50 KT 60 MPH
72H 10/1800Z 12.9N 121.8W 75 KT 85 MPH
96H 11/1800Z 14.0N 125.5W 85 KT 100 MPH
120H 12/1800Z 16.0N 129.0W 85 KT 100 MPH

$$
Forecaster Berg

[cycloneye]

TROPICAL DEPRESSION FOUR-E DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016
900 PM MDT THU JUL 07 2016

Satellite imagery indicate that the low-level circulation associated
with the depression has become larger and better defined, however
the convection near the center is minimal. Most of the thunderstorm
activity is occurring in bands well to the north and southeast of
the center. There are no reasons to change the initial intensity of
30 kt, and this estimate is probably on the high side since the
Dvorak T-numbers are steady or lower tonight.

The depression has failed to strengthen likely due to the upwelling
left by Hurricane Blas, and this possibility has been taken into
consideration in previous NHC forecasts. Since most of the other
environmental parameters are favorable for intensification, the NHC
forecast still calls for such a process to begin on Friday. More
significant strengthening is anticipated beyond 48 hours, although
the NHC forecast is not as aggressive as the SHIPS models.

The overall circulation has been moving very little, and in fact it
has been drifting westward at only 2 kt. This could be the result
of the center rotating around a larger circulation. Nevertheless,
the cyclone is south of a strong subtropical ridge which is forecast
to amplify by most of the global models. This forecast pattern
favors a faster westward motion for the next 3 to 4 days with a
gradual turn to the west-northwest as the system reaches the
southwestern edge of the ridge. The NHC forecast is not very
different from the previous one, and deviates very little from the
multi-model consensus.


FORECAST POSITIONS AND MAX WINDS

INIT 08/0300Z 12.3N 111.7W 30 KT 35 MPH
12H 08/1200Z 12.5N 112.8W 30 KT 35 MPH
24H 09/0000Z 12.8N 114.4W 35 KT 40 MPH
36H 09/1200Z 12.9N 116.2W 45 KT 50 MPH
48H 10/0000Z 13.0N 118.0W 55 KT 65 MPH
72H 11/0000Z 13.0N 122.0W 75 KT 85 MPH
96H 12/0000Z 14.0N 126.5W 85 KT 100 MPH
120H 13/0000Z 16.0N 130.0W 85 KT 100 MPH

$$
Forecaster Avila

[Kingarabian]

GFS Ensembles in excellent agreement in this tracking close to or over Hawaii.

[stormwise]

looks a some what even split in those clusters sub 1000mb and +1000mb.

[cycloneye]

TROPICAL DEPRESSION FOUR-E DISCUSSION NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016
300 AM MDT FRI JUL 08 2016

The cloud pattern of the depression is showing signs of becoming
better organized. There has been an increase in central convection
near the estimated center location and in convective banding to the
north and southeast of the center. The initial intensity remains 30
kt based on a blend of the latest TAFB and SAB Dvorak estimates.
Slow strengthening is forecast during the next 24 hours, while the
cyclone moves over a cool patch of SSTs in the wake of Hurricane
Blas. After that time, the intensification rate should increase as
the cyclone will be moving over warm SSTs in a low shear
environment. In 4 to 5 days, the shear is expected to increase and
SSTs cool along the track, which should result in weakening. The
new NHC intensity forecast is a little below the consensus aid
IVCN during the first 24 hours and then close to the consensus
through 48 hours. Beyond that time the official forecast is higher
than the consensus but not as aggressive as the SHIPS model.

The initial motion estimate is a rather uncertain 275/05 given the
uncertainty in the exact center location. The cyclone should be
steered more quickly westward by a building subtropical ridge to the
north through the next 2 to 3 days. After that time, a west-
northwestward turn is forecast as the system reaches the
southwestern edge of the ridge. The guidance has shifted northward
this cycle in the short term, in particular the ECMWF, which is now
well north of the rest of the models through 48 hours. The new NHC
track has been adjusted to the north this cycle, but still lies a
little south of the multi-model consensus. Confidence in the
details of the track forecast is lower than normal given that the
system is still organizing.

FORECAST POSITIONS AND MAX WINDS

INIT 08/0900Z 12.5N 112.0W 30 KT 35 MPH
12H 08/1800Z 12.7N 113.1W 35 KT 40 MPH
24H 09/0600Z 13.0N 115.0W 40 KT 45 MPH
36H 09/1800Z 13.2N 116.7W 50 KT 60 MPH
48H 10/0600Z 13.5N 119.0W 60 KT 70 MPH
72H 11/0600Z 14.2N 123.3W 85 KT 100 MPH
96H 12/0600Z 15.7N 127.5W 85 KT 100 MPH
120H 13/0600Z 17.3N 131.2W 75 KT 85 MPH

$$
Forecaster Brennan

[MGC]

TD 4 appears to be quite a large system. Should take a while to get consolidated......MGC

[Hurricaneman]

Is now a tropical storm as of 7AMPST

[1900hurricane]

000
WTPZ44 KNHC 081452
TCDEP4

TROPICAL STORM CELIA DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016
900 AM MDT FRI JUL 08 2016

The cloud pattern of the tropical depression has become better
organized, with first-light visible imagery showing a ragged central
dense overcast surrounded by a complex of outer bands. Subjective
Dvorak intensity estimates are 30-35 kt, while AMSU and Advanced
Dvorak technique estimates from CIMSS are near 50 kt. Based on
this, the depression is upgraded to Tropical Storm Celia with winds
of 40 kt.

The initial motion is 275/6. There is little change from the
forecast philosophy from the previous advisory. Celia should be
steered westward with an increase in forward speed by a building
subtropical ridge to the north through the next 2 to 3 days. After
that time, a west-northwestward turn is forecast as the system
nears the southwestern edge of the ridge. The guidance has nudged
a little to the north for the first 36 hours or so, and thus this
part of the forecast track is also adjusted northward. Otherwise,
the track is an update of the previous NHC advisory.

Celia is forecast to be in an environment of light vertical wind
shear for the next 3-4 days. However, during the next 24-36 hours
the cyclone will pass near or over an area of cooler sea surface
temperatures left in the wake of Hurricane Blas. This should slow
intensification during this time. The storm is expected to reach
warmer water from 36-96 hours and significant strengthening is
expected at that time. The intensity forecast calls for a peak
intensity of 90 kt, which is below that forecast by the SHIPS and
LGEM models. From 96-120 hours, Celia should again encounter cooler
sea surface temperatures, which should cause the cyclone to weaken.


FORECAST POSITIONS AND MAX WINDS

INIT 08/1500Z 12.6N 112.8W 40 KT 45 MPH
12H 09/0000Z 12.9N 114.0W 45 KT 50 MPH
24H 09/1200Z 13.3N 116.0W 50 KT 60 MPH
36H 10/0000Z 13.5N 118.1W 55 KT 65 MPH
48H 10/1200Z 13.8N 120.4W 65 KT 75 MPH
72H 11/1200Z 14.5N 125.0W 90 KT 105 MPH
96H 12/1200Z 16.0N 129.0W 90 KT 105 MPH
120H 13/1200Z 17.5N 133.0W 75 KT 85 MPH

$$

[StormChaser75]

the forcast track of tropical storm celia. .

[gatorcane]

Saved vis loop

[cycloneye]

TROPICAL STORM CELIA DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016
300 PM MDT FRI JUL 08 2016

The cloud pattern of Celia is currently comprised of a complex of
curved convective bands around a small area of central convection,
which is less widespread than 6 hours ago. Subjective Dvorak
intensity estimates from SAB and TAFB remain 30-35 kt, while AMSU,
Advanced Dvorak Technique estimates, and satellite consensus
estimates from CIMSS range from 40-55 kt. The initial intensity
remains 40 kt for this advisory.

The center of Celia has jogged northward during the past few hours,
and the initial motion is now 290/5. Other than that, the forecast
track and philosophy have changed little since the last advisory.
Celia should turn westward during the next 12 hours due to a
building subtropical ridge to the north of the cyclone, and it
subsequently should continue westward with an increase in forward
speed through the next 2 to 3 days. After that time, a
west-northwestward turn is forecast as the system nears the
southwestern edge of the ridge. The guidance is tightly clustered
in support of this scenario, with no significant outliers in the
reliable dynamical models or the consensus models. The new forecast
track is nudged a little to the north of the previous track for the
first 72 hours or so based on the current position and motion. After
that, it is similar to the previous forecast.

Celia is forecast to be in an environment of light vertical wind
shear for the next 4-5 days. However, during the next 24 hours the
cyclone will pass near or over an area of cooler sea surface
temperatures left in the wake of Hurricane Blas. This should slow
intensification, and the intensity forecast at 24 hours is thus
lower than most of the guidance. From 24-72 hours, the storm is
expected to reach warmer water, and significant strengthening is
likely due to the favorable upper-level winds. The intensity
forecast now calls for a peak intensity of 95 kt at 72 hours, which
is in best agreement with the LGEM model. From 72-120 hours, Celia
should again encounter cooler sea surface temperatures, which should
cause the cyclone to weaken.


FORECAST POSITIONS AND MAX WINDS

INIT 08/2100Z 13.0N 113.2W 40 KT 45 MPH
12H 09/0600Z 13.3N 114.8W 45 KT 50 MPH
24H 09/1800Z 13.7N 116.9W 50 KT 60 MPH
36H 10/0600Z 14.0N 119.1W 60 KT 70 MPH
48H 10/1800Z 14.2N 121.5W 70 KT 80 MPH
72H 11/1800Z 15.0N 126.0W 95 KT 110 MPH
96H 12/1800Z 16.5N 130.0W 90 KT 105 MPH
120H 13/1800Z 18.5N 134.0W 75 KT 85 MPH

$$
Forecaster Beven

[Alyono]

models are FINALLY producing reasonable intensity forecasts for this. Likely cat 1 peak

still not seeing any HI threat from this. This is going to be taking the long road over cold water