EPAC: DOUGLAS - Post-Tropical

[hurricanes1234]

Somehow, someway, Douglas is up to 40 knts per the ATCF.

EP, 04, 2014070100, , BEST, 0, 182N, 1147W, 40, 1000, TS, 34, NEQ, 0, 100, 60, 0, 1008, 275, 60, 0, 0, E, 0, , 0, 0, DOUGLAS, M,

Actually, it looks ever so slightly more compact now. Still disorganised but a little better than what we were seeing before. Also, ADT estimates bring it up to nearly 45 knots.

CI# /Pressure/ Vmax
2.9 / 999.9mb/ 43.0kt

Pretty much spot on. Structure still looks too good to be a TD and appears to be consolidating.

Wonder what happens as we head into Dmax.

I don't think it can go beyond 50 mph because of dry air and cool waters. I'd expect diurnal maximum to be much the same as it is now, which isn't bad. I'm a little surprised at the last minute strengthening.

[cycloneye]

TROPICAL STORM DOUGLAS DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042014
800 PM PDT MON JUN 30 2014

Tropical Storm Douglas has developed some well-defined inner
core banding features this evening, as seen in the GOES-West
geostationary imagery. Correspondingly, the intensity estimates
have inched upward: a blend of the TAFB and SAB Dvorak
classifications averages 40 kt, the Advanced Dvorak Technique is at
43 kt, and the CIMSS AMSU technique suggests 48 kt. The initial
intensity is thus set at 40 kt, but this could be slightly low.

It appears that Douglas may soon be at its peak intensity, as the
sea surface temperatures and convective instability start dropping
steadily in about a day despite rather low vertical wind shear. The
intensity guidance is tightly clustered and suggests gradual
weakening after 24 h until loss of deep convection in about 3-4
days causes the system to become a remnant low. The intensity
forecast is slightly above the previous advisory, mainly due to the
short-term intensity trend.

Douglas is moving west-northwestward at about 8 kt. The system is
primarily being steered by a broad ridge to its north, which should
weaken within the next day or so as a short-wave trough approaches
from the west. When this occurs, the steering flow becomes almost
negligible and Douglas is likely to drift slowly west-northwestward
between 24 and 72 h. By days 4 and 5, the remnant low of Douglas
will accelerate westward in the low-level tradewind flow. The
track forecast is based upon TVCE - the variable consensus model -
and is slightly north of the previous advisory.


FORECAST POSITIONS AND MAX WINDS

INIT 01/0300Z 18.4N 114.9W 40 KT 45 MPH
12H 01/1200Z 19.0N 115.5W 45 KT 50 MPH
24H 02/0000Z 19.4N 116.1W 45 KT 50 MPH
36H 02/1200Z 19.6N 116.5W 40 KT 45 MPH
48H 03/0000Z 19.7N 116.8W 35 KT 40 MPH
72H 04/0000Z 20.0N 118.0W 30 KT 35 MPH
96H 05/0000Z 20.5N 120.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 06/0000Z 21.0N 123.0W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Landsea

[Yellow Evan]

Actually, it looks ever so slightly more compact now. Still disorganised but a little better than what we were seeing before. Also, ADT estimates bring it up to nearly 45 knots.

CI# /Pressure/ Vmax
2.9 / 999.9mb/ 43.0kt

Pretty much spot on. Structure still looks too good to be a TD and appears to be consolidating.

Wonder what happens as we head into Dmax.

I don't think it can go beyond 50 mph because of dry air and cool waters. I'd expect diurnal maximum to be much the same as it is now, which isn't bad. I'm a little surprised at the last minute strengthening.

Neither are too unfavorable. It is located in deep tropics, and for the next day or so, conditions looks okay. Could make a run at 50-55 knts IMO.

[cycloneye]

TROPICAL STORM DOUGLAS DISCUSSION NUMBER 11
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042014
200 AM PDT TUE JUL 01 2014

The cloud pattern associated with Douglas has not changed much over
the past few hours, with some broken convective bands seen
southeast and west of the center. A blend of the latest Dvorak
estimates from TAFB and SAB and the latest UW-CIMSS ADT yields
an initial intensity of 40 kt. While the shear is expected to remain
low, Douglas will be moving over cool sea surface temperatures and
into a more stable thermodynamic environment during the next few
days. This should result in a gradual spin down of the large
circulation, and Douglas is expected to weaken to a remnant low by
day 4.

The initial motion estimate is 315/06. As the ridge north of
Douglas weakens later today, the cyclone should slow down and drift
west-northwestward and westward for the next 2-3 days. After that
time, the shallow cyclone will be steered more steadily westward by
the trade wind flow. The new NHC track forecast is largely an
update of the previous one through the forecast period.

FORECAST POSITIONS AND MAX WINDS

INIT 01/0900Z 18.8N 115.3W 40 KT 45 MPH
12H 01/1800Z 19.1N 115.8W 40 KT 45 MPH
24H 02/0600Z 19.4N 116.2W 40 KT 45 MPH
36H 02/1800Z 19.6N 116.6W 35 KT 40 MPH
48H 03/0600Z 19.7N 117.0W 35 KT 40 MPH
72H 04/0600Z 20.0N 118.5W 30 KT 35 MPH
96H 05/0600Z 20.5N 120.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 06/0600Z 21.0N 123.5W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Brennan

[hurricanes1234]

Both Douglas and Elida are weakened on the 12:00 Best Track. Douglas is in bold:

04E DOUGLAS 140701 1200 18.9N 115.4W EPAC 35 1002
05E ELIDA 140701 1200 17.4N 104.3W EPAC 40 1004

I'm suspecting that Douglas peaked last night or early this morning. I doubt it will strengthen again.

[cycloneye]

TROPICAL STORM DOUGLAS DISCUSSION NUMBER 12
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042014
800 AM PDT TUE JUL 01 2014

Conventional satellite imagery indicates that the Douglas' cloud
pattern has not changed much this morning, except for some cooling
of cloud top temperatures northwest of the center. A blend of
Dvorak intensity estimates and an ADT CI value of 2.2 are used to
lower the initial wind speed estimate to 35 kt on this advisory.
Although the vertical wind shear is forecast to remain low during
the next few days, Douglas will be traversing gradually decreasing
sea surface temperatures and ingesting somewhat drier and more
stable air. These factors should result in a gradual weakening of
the cyclone, and remnant low status is indicated by day 3. The NHC
intensity forecast is reduced slightly relative to the previous one
and is near the multi-model consensus.

The initial motion estimate is 310/06. The subtropical ridge to the
north of the cyclone is weakening, which should result in a further
reduction of forward speed on a west-northwesterly heading during
the next couple of days. Once Douglas becomes a shallower vortex in
2-3 days, a bend of the track toward the west is expected, followed
by some increase in forward speed. The NHC track forecast is
basically an update of the previous one, nudged slightly to the
north in the direction of the multi-model consensus.


FORECAST POSITIONS AND MAX WINDS

INIT 01/1500Z 19.1N 115.9W 35 KT 40 MPH
12H 02/0000Z 19.4N 116.2W 35 KT 40 MPH
24H 02/1200Z 19.7N 116.6W 35 KT 40 MPH
36H 03/0000Z 19.9N 116.9W 30 KT 35 MPH
48H 03/1200Z 20.1N 117.3W 30 KT 35 MPH
72H 04/1200Z 20.5N 118.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 05/1200Z 21.0N 120.7W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 06/1200Z 21.5N 124.4W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Kimberlain

[Hurricane_Luis]

Tropical Storm Douglas



A CDO could be forming.

[Kingarabian]

Better than anything it were yesterday:


Exposed.

[hurricanes1234]

Better than anything it were yesterday:
https://imagizer.imageshack.us/v2/657x6 ... 0/64xn.jpg

Exposed.

I agree. The structure is now more compact and rounded. In my opinion, if it did this earlier, it might have become stronger.

[hurricanes1234]

Back up to 40 knots on 18:00 Best Track.

04E DOUGLAS 140701 1800 19.1N 115.9W EPAC 40 1001

[cycloneye]

TROPICAL STORM DOUGLAS DISCUSSION NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042014
200 PM PDT TUE JUL 01 2014

Since the last advisory, deep convection associated with Douglas has
consolidated into a long band wrapping around the western and
southern portions of the broad circulation. As a result, Dvorak
intensity estimates have increased slightly to 3.0/45 kt from TAFB
and SAB, while the latest UW-CIMSS ADT CI value is at 2.6/35 kt. A
blend of these data is used to arrive at an initial intensity of 40
kt for this advisory. Even though Douglas is in a nearly shear-free
environment, the cyclone is traversing gradually decreasing sea
surface temperatures and ingesting somewhat drier and more stable
air. Given these negative thermodynamic factors, the intensity
guidance shows a slow decay of the cyclone's winds during the next
few days. The NHC intensity forecast follows this philosophy and is
about the same as the previous one. The forecast is in basic
agreement with the latest multi-model consensus, and still shows
remnant low status on day 3 and dissipation just after day 5.

The latest fixes suggest that the cyclone's forward speed may be
decreasing, and the initial motion estimate is now 310/04. A
weakness in the subtropical ridge north of Douglas should result
in a further reduction in forward speed, with a possible bend of the
track toward the north-northwest during the next day or so. As the
cyclone becomes shallower, a turn toward the west-northwest and
then the west with some increase in forward speed should occur prior
to dissipation. The NHC track forecast is adjusted slightly to the
right on the basis of the latest multi-model consensus but is on the
far left side of the guidance envelope.


FORECAST POSITIONS AND MAX WINDS

INIT 01/2100Z 19.2N 115.9W 40 KT 45 MPH
12H 02/0600Z 19.5N 116.2W 35 KT 40 MPH
24H 02/1800Z 19.9N 116.5W 35 KT 40 MPH
36H 03/0600Z 20.2N 116.8W 30 KT 35 MPH
48H 03/1800Z 20.5N 117.3W 30 KT 35 MPH
72H 04/1800Z 21.0N 119.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 05/1800Z 21.6N 122.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 06/1800Z 21.8N 125.5W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Kimberlain

[hurricanes1234]

Not bad, but these are just fluctuations, not real strengthening, in my opinion. It's done fairly well considering a forecast not too long ago called for steady weakening and it jumped up to 45 mph, went down again to 40 mph, and is now back up to 45 mph. But the thermodynamic environment is not good, so weakening should begin soon.

[Yellow Evan]

Not bad, but these are just fluctuations, not real strengthening, in my opinion. It's done fairly well considering a forecast not too long ago called for steady weakening and it jumped up to 45 mph, went down again to 40 mph, and is now back up to 45 mph. But the thermodynamic environment is not good, so weakening should begin soon.

Shear is low, which helps a bit.

[cycloneye]

TROPICAL STORM DOUGLAS DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042014
800 PM PDT TUE JUL 01 2014

Douglas has maintained a tight curved band of deep convection near
its center, primarily within the western semicircle. Consequently,
the TAFB and SAB Dvorak CI numbers have remained the same and thus
the intensity is kept at 40 kt. While Douglas should remain under
light vertical shear for the next few days, the gradually cooling
waters and drier stable air that the cyclone will encounter
should cause the convection to diminish and, in about 36-48 hours,
eventually to cease. The large size of Douglas suggests that it
will wind down gradually, even if the convection dissipates quicker
than expected. The intensity forecast is based upon the tight
consensus of intensity models and is nearly the same as that in the
previous advisory.

Douglas has been meandering this evening with a longer-term motion
of 340/2. The steering for the cyclone has nearly collapsed as the
mid-level ridge to the north has weakened due to a short-wave
trough impinging upon it. As Douglas becomes a weaker, shallower
vortex, it should be advected faster toward the west-northwest
in about 3 days and then westward by day 5 in the low-level
tradewind flow. The track forecast is based upon the tightly
clustered multi-model consensus - TVCE - with somewhat less weight
placed upon the ECMWF model, since this model has had a distinct
equatorward bias for Douglas. This track prediction is slightly
poleward of that from the previous advisory.


FORECAST POSITIONS AND MAX WINDS

INIT 02/0300Z 19.4N 115.7W 40 KT 45 MPH
12H 02/1200Z 19.7N 115.9W 35 KT 40 MPH
24H 03/0000Z 20.1N 116.1W 35 KT 40 MPH
36H 03/1200Z 20.4N 116.4W 30 KT 35 MPH
48H 04/0000Z 20.8N 116.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 05/0000Z 22.0N 119.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 06/0000Z 23.0N 122.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 07/0000Z 23.0N 125.0W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Landsea

[Steve820]

Douglas has probably reached peak intensity. I wouldn't be surprised if it briefly restrengthens to 50 mph though. From here on out, it should gradually weaken before dissipating by the end of the week.

[Kingarabian]

Ooo la la la. Douglas has a decent CDO going on...

[hurricanes1234]

And I thought Douglas was bad.

Look at Elida, which only weakened from its classification. Douglas formed before Elida and it has outlasted it. Makes me appreciate him more!

[cycloneye]

TROPICAL STORM DOUGLAS DISCUSSION NUMBER 16
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042014
800 AM PDT WED JUL 02 2014

Douglas's structure has changed little since the last advisory.
Deep convection associated with the storm is losing a bit of
organization but remains compact near the low-level center. A
blend of Dvorak final-T and CI numbers from TAFB, SAB, and the
objective ADT supports maintaining an initial intensity of 40 kt.

Douglas is trapped in an environment of weak steering and is
drifting northwestward...or 325/2 kt...toward a break in the
subtropical ridge. The subtropical high to the west of Douglas is
expected to remain in place for another 48 hours or so, which will
continue a slow northwestward motion. After 48 hours, the western
subtropical high weakens while mid-level ridging strengthens over
the western United States. This pattern evolution should cause
Douglas to turn west-northwestward and accelerate between 72-120
hours. The track guidance has shifted noticeably to the right of
the previous NHC forecast, especially through 24 hours and again
between 96-120 hours. The updated forecast is also moved to the
right, lying near the ECMWF and just to the left of the model
consensus TVCE.

Given Douglas's slow motion in the short term, sea surface
temperatures will only gradually decrease along the forecast track
during the next 24-36 hours. Vertical shear is forecast to remain
low, and as a result, Douglas should be able to hang on as a
tropical storm for another day or so. The ocean becomes much colder
once Douglas accelerates to the west-northwest, and the cyclone is
expected to become a remnant low by 48 hours. The new NHC intensity
forecast is very similar to the previous one.

FORECAST POSITIONS AND MAX WINDS

INIT 02/1500Z 19.7N 116.0W 40 KT 45 MPH
12H 03/0000Z 20.0N 116.1W 35 KT 40 MPH
24H 03/1200Z 20.4N 116.4W 35 KT 40 MPH
36H 04/0000Z 20.9N 117.0W 30 KT 35 MPH
48H 04/1200Z 21.4N 118.0W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 05/1200Z 22.6N 120.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 06/1200Z 24.0N 124.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 07/1200Z 24.5N 127.5W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Berg

[cycloneye]

TROPICAL STORM DOUGLAS DISCUSSION NUMBER 17
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042014
200 PM PDT WED JUL 02 2014

Convection associated with Douglas is quickly losing its
organization. In addition, a 1758 UTC ASCAT-B pass indicated that
the maximum winds have decreased slightly, and the initial
intensity is set at 35 kt for this advisory. Visible satellite
images show that dry and stable air continues to infiltrate into
Douglas's circulation, and along with decreasing sea surface
temperatures, will contribute to additional weakening during the
next couple of days. Douglas is now forecast to become a tropical
depression in 12 hours and degenerate into a remnant low by 36
hours.

Douglas is creeping north-northwestward with an initial motion of
330/2 kt. However, the cyclone is expected to turn back to the
northwest later tonight and eventually accelerate to the
west-northwest by 48 hours when mid-level ridging builds over the
western United States. Low-level ridging is forecast to steer the
remnant low west-northwestward to westward between days 3 and 5.
The track guidance is tightly clustered on this advisory cycle, and
no significant changes were required to the NHC track forecast.

FORECAST POSITIONS AND MAX WINDS

INIT 02/2100Z 20.0N 116.2W 35 KT 40 MPH
12H 03/0600Z 20.2N 116.4W 30 KT 35 MPH
24H 03/1800Z 20.6N 116.9W 30 KT 35 MPH
36H 04/0600Z 21.0N 117.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 04/1800Z 21.5N 118.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 05/1800Z 22.8N 121.7W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 06/1800Z 24.0N 125.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 07/1800Z 24.0N 128.0W 15 KT 15 MPH...POST-TROP/REMNT LOW

$$
Forecaster Berg

[Yellow Evan]

Dogulas' days are numbered.