EPAC: DALILA - Post-Tropical

[Kingarabian]

We have TD5.

[cycloneye]

Tropical Depression Five-E Discussion Number 1
NWS National Hurricane Center Miami FL EP052019
200 AM PDT Mon Jul 22 2019

The area of disturbed weather and low pressure system located about
600 nmi southwest of Baja California Sur that the NHC has been
monitoring for the past several days has finally developed a
sufficient inner-core wind field and enough organized deep
convection to be classified as a tropical cyclone. The initial
intensity is set at 30 kt based on two ASCAT passes between
0430-0530Z that showed 30-31 kt wind vectors in the western
quadrant, which corresponds well with the latest TAFB Dvorak
satellite intensity estimate of T2.0/30 kt from TAFB.

The initial motion estimate is an uncertain 360/08 kt due to the
lack of a well-defined center until recently. However, the NHC model
guidance is in surprisingly good agreement on the cyclone moving
northward for the next 36-48 hours around the eastern periphery of a
broad mid-level low/trough located to the west of the depression. By
72 h and continuing through 120 h, the cyclone is forecast to move
northwestward as a weakening remnant low pressure system. The NHC
forecast track lies close to a blend of the various consensus
models, and is about midway between the GFS and ECMWF model
solutions that bound on the eastern and western fringes,
respectively, of the track guidance envelope.

Modest north to northeasterly vertical wind shear and occasional
intrusions of dry air are expected to hinder development and
strengthening for the next 48 hours or so. By late on day 2 and
especially by day 3, the cyclone will be moving over sub-26 deg C
sea-surface temperatures, which will induce at least steady
weakening despite decreasing vertical wind shear conditions during
that time. The official intensity forecast is similar to but
slightly higher higher than the IVCN and HCCA intensity consensus
models, with the latter guidance calling for no strengthening.

FORECAST POSITIONS AND MAX WINDS

INIT 22/0900Z 15.0N 116.2W 30 KT 35 MPH
12H 22/1800Z 16.3N 116.3W 30 KT 35 MPH
24H 23/0600Z 17.9N 116.6W 35 KT 40 MPH
36H 23/1800Z 19.2N 117.0W 40 KT 45 MPH
48H 24/0600Z 20.4N 117.7W 35 KT 40 MPH
72H 25/0600Z 22.0N 119.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 26/0600Z 23.2N 122.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 27/0600Z 24.6N 124.5W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Stewart

[cycloneye]

Tropical Depression Five-E Discussion Number 2
NWS National Hurricane Center Miami FL EP052019
800 AM PDT Mon Jul 22 2019

A recent satellite microwave pass indicates that the depression has
not gotten any better organized this morning. It appears that
northeasterly shear is keeping much of the convection displaced to
the west of the center of circulation. Both the latest TAFB
Dvorak satellite intensity estimate and UW-CIMMS objective intensity
estimate indicate that the system remains a 30-kt depression.

The initial motion of the depression is 355/08 kt. Model guidance is
in good agreement on a continuation of this general motion for the
next 36-48 hours as the depression is steered between a weak
mid-level trough to its west, and a building mid-level ridge to its
northeast. After 48 hours, the system should begin to weaken and
turn toward the northwest as it becomes steered by the lower-level
flow. The latest NHC forecast track is very near the previous
official forecast and is near the track guidance consensus.

Although convection has increased this morning, the shear is
preventing the inner core of the depression from becoming better
established. This shear is forecast to remain in the 15-20 kt range
for the next 48 hours which should continue to prevent any
significant intensification during that time frame. Since the other
environmental parameters are somewhat favorable for intensification
during the next day or so, the depression will likely become a
minimal tropical storm later today or tonight. After 48 hours, the
system will move over waters below 26 C and into a stable
atmospheric environment which should induce steady weakening. By 72
hours, the system is expected to become a remnant low, with
dissipation likely by 120 hours. The official intensity forecast is
close to the previous NHC forecast, and is near the more reliable
intensity guidance.

FORECAST POSITIONS AND MAX WINDS

INIT 22/1500Z 15.9N 116.3W 30 KT 35 MPH
12H 23/0000Z 17.0N 116.5W 35 KT 40 MPH
24H 23/1200Z 18.5N 116.8W 35 KT 40 MPH
36H 24/0000Z 19.8N 117.3W 35 KT 40 MPH
48H 24/1200Z 20.8N 118.0W 35 KT 40 MPH
72H 25/1200Z 22.3N 120.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 26/1200Z 23.5N 122.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 27/1200Z 24.0N 125.0W 20 KT 25 MPH...DISSIPATED

$$
Forecaster Latto/Pasch

[NDG]

Yet another EPAC system that looks more subtropical than pure tropical, as soon it gets closer to the cooler SSTs.

[NDG]

Like I said, TD 5E may have a closed circulation but is broad, with multiple eddies circulating around the COC and convection is far SW of its COC. On satellite, only, 94L has a better presentation. IMO.

[Yellow Evan]

Looks better than it did 12 hours ago. Not elongated in the same axis is was though clearly having shear issues.

[Kingarabian]

Like I said, TD 5E may have a closed circulation but is broad, with multiple eddies circulating around the COC and convection is far SW of its COC. On satellite, only, 94L has a better presentation. IMO.

[url]https://i.imgur.com/qBIPh69.gif[url]

Looks like Barry's twin in its early stages.

[cycloneye]

Tropical Depression Five-E Discussion Number 3
NWS National Hurricane Center Miami FL EP052019
200 PM PDT Mon Jul 22 2019

The depression is struggling to become better organized. Visible
satellite imagery shows multiple low-level swirls moving about a
mean center of circulation, with the deep convection being confined
to the southwestern semicircle due to northeasterly shear. Both
subjective and objective satellite intensity estimates indicate that
the system intensity remains 30 kt.

Since the exact center is somewhat difficult to locate, the initial
motion is a rather uncertain 345/08kt. There has been a slight
westward shift in the majority of the track guidance, and this is
possibly due to them steering a weaker system than previously
forecast. The depression is expected to continue to move
north-northwest for the next 24-36 hours between a weak mid-level
trough to its west, and a building mid-level ridge to its
northeast. After 36 hours, the system should make a gradual
turn toward the west-northwest as the cyclone weakens and becomes
carried by the low-level steering currents.

There is a shrinking window of opportunity for the depression to get
its act together before it moves over SSTs below 26 C and into a
stable atmospheric environment in 24-36 hours. Additionally, the 15
to 20 kt of shear currently over the system may prevent it from
intensifying any further. However, the official forecast calls for
the depression to intensify slightly over marginal SSTs into a
weak tropical storm tonight, followed by a weakening trend beginning
in about 24 hours. The cyclone should weaken into a remnant low by
48 hours and then dissipate late this week. The intensity forecast
through 24 hours remains the same as the previous advisory, but
it has been lowered beyond 24 hours and is in agreement with the
majority of the intensity guidance.

FORECAST POSITIONS AND MAX WINDS

INIT 22/2100Z 16.7N 116.6W 30 KT 35 MPH
12H 23/0600Z 17.8N 116.9W 35 KT 40 MPH
24H 23/1800Z 19.1N 117.4W 35 KT 40 MPH
36H 24/0600Z 20.2N 118.0W 30 KT 35 MPH
48H 24/1800Z 21.0N 119.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 25/1800Z 22.1N 121.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 26/1800Z...DISSIPATED

$$
Forecaster Latto/Pasch

[Kingarabian]

Deep convection continues to persist near its center(s):

[Tailspin]

Seems to be just troughy @ 500mb the other profile levels look good.
https://earth.nullschool.net/#current/w ... 14.64,2274

[cycloneye]

Tropical Depression Five-E Discussion Number 4
NWS National Hurricane Center Miami FL EP052019
800 PM PDT Mon Jul 22 2019

This evening's visible satellite presentation consists of a rather
ragged and shapeless cloud pattern with multiple cloud swirls seen
rotating around the mean surface circulation center. The Dvorak
satellite intensity estimates from both TAFB and SAB remain
unchanged (T2.0/30 kt) as well as the initial intensity.

There are no changes to the forecast intensity philosophy. Both
the GFS and ECMWF SHIPS indicate that the northerly shear currently
impinging on the northeastern portion of the system will persist
through the forecast period. This inhibiting wind pattern along
with cooler oceanic surface temperatures, ahead of the predicted
track, should cause the cyclone to degenerate into a remnant low
in 48 hours with dissipation in 4 days or less. The only model
that shows strengthening to tropical storm status is the COAMPS-TC.
For continuity purposes, I've elected to maintain this slight 12-24
hour intensification period in the official forecast.

Because of the ill-defined circulation, the initial motion is
estimated to be a bit uncertain north-northwestward, or 345/7
kt, within the low- to mid-level steering flow produced by high
pressure located over the southwestern United States. The
depression should continue moving in a general northwestward
direction toward a break in the ridge to the northwest of the
cyclone during the next 2 days. Afterward, as the system begins to
weaken, a turn toward the west-northwest, within the tradewind flow,
is anticipated. The model guidance is tightly clustered with the
exception being the left outlier UKMET. The only adjustment in the
NHC forecast is, again, a shift slightly to the left of the previous
advisory, but follows both the TVCE and HCCA consensus models
closely.

FORECAST POSITIONS AND MAX WINDS

INIT 23/0300Z 17.6N 116.8W 30 KT 35 MPH
12H 23/1200Z 18.5N 117.2W 35 KT 40 MPH
24H 24/0000Z 19.6N 117.9W 35 KT 40 MPH
36H 24/1200Z 20.5N 118.8W 30 KT 35 MPH
48H 25/0000Z 21.2N 119.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 26/0000Z 22.5N 122.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 27/0000Z...DISSIPATED

$$
Forecaster Roberts

[Nancy Smar]

DALILA, EP, E, , , , , 05, 2019, TS, R, 2019071412, 9999999999, , 013, , , 8, WARNING, 5, EP052019

[Tailspin]

https://imgur.com/Gj1HYVJ
Getting some heavy storms now around the centre

[Astromanía]

Hi Dalila!

[cycloneye]

Tropical Storm Dalila Discussion Number 5
NWS National Hurricane Center Miami FL EP052019
200 AM PDT Tue Jul 23 2019

Deep convection has become stronger and closer to the center of the
cyclone during the past several hours. While the circulation is
still elongated, it has become better defined, with the latest ASCAT
pass at 0440 UTC showing 30-35 kt winds in the southern quadrant.
Since TAFB, ADT and SATCON have the current intensity as a tropical
storm, plus the recent increase in organization, the current wind
speed has been set to 35 kt.

Dalila is probably near peak intensity. Since SSTs drop off later
today, along with a continuation of moderate northerly shear,
weakening should begin on Wednesday. In a couple of days, SSTs near
24C, dry air aloft, and a more stable atmosphere should contribute
to Dalila losing deep convection, thus becoming a remnant low. This
is the solution provided by much of the guidance, and the latest NHC
intensity prediction is close to the previous one.

The cyclone has been moving erratically at 330/6 due to the center
trying to reform near the strong convection to the south. A
mid-level ridge over the southwestern United States should provide
similar steering during the next day or so, causing a motion
generally toward the northwest by Wednesday. As Dalila weakens, it
will likely turn more to the west-northwest on Thursday within the
low-level flow. Similar to the past few cycles, model guidance is
continuing to shift westward, and the official forecast follows that
trend, not terribly far from the eastern Pacific track consensus
model TVCE.

FORECAST POSITIONS AND MAX WINDS

INIT 23/0900Z 18.0N 117.3W 35 KT 40 MPH
12H 23/1800Z 18.8N 117.8W 35 KT 40 MPH
24H 24/0600Z 19.8N 118.6W 30 KT 35 MPH
36H 24/1800Z 20.6N 119.5W 30 KT 35 MPH
48H 25/0600Z 21.3N 120.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 26/0600Z 22.3N 123.3W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 27/0600Z...DISSIPATED

$$
Forecaster Blake

[cycloneye]

Tropical Storm Dalila Discussion Number 5
NWS National Hurricane Center Miami FL EP052019
200 AM PDT Tue Jul 23 2019

Deep convection has become stronger and closer to the center of the
cyclone during the past several hours. While the circulation is
still elongated, it has become better defined, with the latest ASCAT
pass at 0440 UTC showing 30-35 kt winds in the southern quadrant.
Since TAFB, ADT and SATCON have the current intensity as a tropical
storm, plus the recent increase in organization, the current wind
speed has been set to 35 kt.

Dalila is probably near peak intensity. Since SSTs drop off later
today, along with a continuation of moderate northerly shear,
weakening should begin on Wednesday. In a couple of days, SSTs near
24C, dry air aloft, and a more stable atmosphere should contribute
to Dalila losing deep convection, thus becoming a remnant low. This
is the solution provided by much of the guidance, and the latest NHC
intensity prediction is close to the previous one.

The cyclone has been moving erratically at 330/6 due to the center
trying to reform near the strong convection to the south. A
mid-level ridge over the southwestern United States should provide
similar steering during the next day or so, causing a motion
generally toward the northwest by Wednesday. As Dalila weakens, it
will likely turn more to the west-northwest on Thursday within the
low-level flow. Similar to the past few cycles, model guidance is
continuing to shift westward, and the official forecast follows that
trend, not terribly far from the eastern Pacific track consensus
model TVCE.

FORECAST POSITIONS AND MAX WINDS

INIT 23/0900Z 18.0N 117.3W 35 KT 40 MPH
12H 23/1800Z 18.8N 117.8W 35 KT 40 MPH
24H 24/0600Z 19.8N 118.6W 30 KT 35 MPH
36H 24/1800Z 20.6N 119.5W 30 KT 35 MPH
48H 25/0600Z 21.3N 120.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 26/0600Z 22.3N 123.3W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 27/0600Z...DISSIPATED

$$
Forecaster Blake

[DioBrando]

hey there dalila what's it like in the middle of the pacific

[TorSkk]

Tropical Storm Dalila Discussion Number 6
NWS National Hurricane Center Miami FL EP052019
800 AM PDT Tue Jul 23 2019

Dalila continues to battle 15-20 kt of northerly shear with deep
convection displaced across the southern semicircle of the storm.
Satellite imagery indicates that there are multiple low level swirls
encircling a mean center that is located just north of the edge of
the convection. The latest Dvorak intensity estimates from both
TAFB and UW-CIMMS support maintaining a 35 kt initial intensity for
this advisory.

The initial motion is 330/07. A mid-level ridge over the
southwestern United States will steer the cyclone to the northwest
through much of tonight. As the system weakens, it will become
steered by an increasing component of the low-level flow, resulting
in a turn more to the west-northwest Wednesday and Thursday.
Similar to the past few model cycles, the latest guidance has
shifted slightly to the west, and therefore the official forecast
track has also been adjusted a little in that direction.

Dalila is approaching the 26 C isotherm and the center is forecast
to cross it in about 12 hours, which should cause a weakening trend
to begin by tonight. In addition, the current shear is not expected
to decrease significantly in the next day or so, and during that
time the cyclone will be moving into a drier, more stable
environment. These factors should cause Dalila to lose its deep
convection and become a remnant low by Wednesday night. The latest
forecast is essentially an update of the previous official intensity
forecast.

FORECAST POSITIONS AND MAX WINDS

INIT 23/1500Z 18.7N 117.7W 35 KT 40 MPH
12H 24/0000Z 19.4N 118.3W 35 KT 40 MPH
24H 24/1200Z 20.3N 119.2W 30 KT 35 MPH
36H 25/0000Z 20.9N 120.3W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 25/1200Z 21.5N 121.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 26/1200Z...DISSIPATED

$$
Forecaster Latto/Brown

[Yellow Evan]

Much to the surprise of no one, Dalila looks like garbage still.

[Yellow Evan]

TXPZ24 KNES 231823
TCSENP

A. 05E (DALILA)

B. 23/1800Z

C. 18.9N

D. 117.8W

E. THREE/GOES-W

F. T1.0/2.0/W1.0/24HRS

G. IR/EIR/VIS

H. REMARKS...SYSTEM IS CHARACTERIZED BY LOOSELY DEFINED CLOUD LINES
AND A LOW LEVEL CENTER LESS THAN 75 NM FROM THE SMALL AREA OF COLD
OVERCAST. THIS RESULTS IN A DT OF 2.0. MET IS 1.5. PT IS 1.0. FT IS
BASED ON PT DUE TO UNCERTAINTY IN LOW LEVEL CENTER POSITION.

I. ADDL POSITIONS

NIL


...LEVINE

PT is not 1.0.