ATL: TEN - Advisories

[cycloneye]

BULLETIN
Tropical Depression Ten Advisory Number 1
NWS National Hurricane Center Miami FL AL102020
800 PM CVT Fri Jul 31 2020

...TROPICAL DEPRESSION FORMS IN THE FAR EASTERN ATLANTIC...
...EXPECTED TO BE SHORT-LIVED...


SUMMARY OF 800 PM CVT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...15.9N 20.0W
ABOUT 265 MI...430 KM E OF THE CABO VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...N OR 355 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.


DISCUSSION AND OUTLOOK
----------------------
At 800 PM CVT (2100 UTC), the center of Tropical Depression Ten was
located near latitude 15.9 North, longitude 20.0 West. The
depression is moving toward the north near 9 mph (15 km/h). A turn
toward the northwest is expected tonight, followed by a turn to the
west-northwest and west on Saturday and Saturday night. On the
forecast track, the center of the depression is expected to pass
north of the northernmost Cabo Verde Islands tonight and Saturday.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
The system could become a short-lived tropical storm later tonight.
However, weakening is forecast to begin on Saturday and the system
is expected to become a remnant low Saturday night.

The estimated minimum central pressure is 1007 mb (29.74 inches).


HAZARDS AFFECTING LAND
----------------------
None


NEXT ADVISORY
-------------
Next complete advisory at 200 AM CVT.

$$
Forecaster Brown


Tropical Depression Ten Discussion Number 1
NWS National Hurricane Center Miami FL AL102020
800 PM CVT Fri Jul 31 2020

Deep convection has recently developed closer to the center of a
small area of low pressure located a couple of hundred miles east of
the Cabo Verde Islands. Earlier ASCAT data indicated peak winds of
around 25 kt, but given the small size of the system and the likely
undersampling of the instrument, the initial intensity is set at 30
kt. This is in line with a Dvorak classification of T2.0 from SAB.
With the recent increase in convective organization, there is a
potential for the depression to become a short-lived tropical storm
tonight. After that time, the environment is forecast to become
increasingly hostile as cooler waters and less favorable
thermodynamic conditions lie ahead. As a result, weakening should
begin on Saturday and the system is forecast to become a remnant low
Saturday night and dissipate shortly thereafter.

The system is moving slightly west of due north, or 355/8 kt. The
depression is forecast to turn northwestward tonight, then
west-northwestward to westward on Saturday and Saturday night as it
moves around the eastern side of a large cyclonic gyre over the far
eastern Atlantic. The track guidance is in relatively good
agreement, and the NHC forecast is near the TVCA multi-model
consensus.


FORECAST POSITIONS AND MAX WINDS

INIT 31/2100Z 15.9N 20.0W 30 KT 35 MPH
12H 01/0600Z 17.3N 21.0W 35 KT 40 MPH
24H 01/1800Z 18.5N 23.2W 30 KT 35 MPH
36H 02/0600Z 18.8N 25.8W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 02/1800Z...DISSIPATED

$$
Forecaster Brown

[cycloneye]

BULLETIN
Tropical Depression Ten Advisory Number 2
NWS National Hurricane Center Miami FL AL102020
200 AM CVT Sat Aug 01 2020

...DEPRESSION PERSISTING OVER THE FAR EASTERN ATLANTIC...
...FORECAST TO BECOME A REMNANT LOW ON SATURDAY...


SUMMARY OF 200 AM CVT...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...17.1N 21.1W
ABOUT 205 MI...330 KM ENE OF THE CABO VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NW OR 310 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.


DISCUSSION AND OUTLOOK
----------------------
At 200 AM CVT (0300 UTC), the center of Tropical Depression Ten was
located near latitude 17.1 North, longitude 21.1 West. The
depression is moving toward the northwest near 14 mph (22 km/h). A
turn toward the west-northwest or west is expected by Saturday
afternoon. On the forecast track, the center of the depression is
expected to move north of the northernmost Cabo Verde Islands on
Saturday.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Although the system could briefly become a short-lived tropical
storm, it is forecast to weaken and become a remnant low within the
next 24 hours.

The estimated minimum central pressure is 1007 mb (29.74 inches).


HAZARDS AFFECTING LAND
----------------------
None


NEXT ADVISORY
-------------
Next complete advisory at 800 AM CVT.

$$
Forecaster Zelinsky


Tropical Depression Ten Discussion Number 2
NWS National Hurricane Center Miami FL AL102020
200 AM CVT Sat Aug 01 2020

The small depression maintained a large burst of convection in its
northwest quadrant for several hours after the last advisory, though
cloud tops have warmed steadily since around 00Z. An ASCAT-B pass
near 2300 UTC showed max winds near 35 kt, but these winds coincided
with the coldest cloud tops in Meteosat imagery at that time,
indicating they may have been rain inflated. Data from ASCAT-C valid
about 40 minutes earlier only showed peak winds closer to 30 kt,
also near the deepest convection. The highest wind retrievals in the
east half of the circulation, where you would often expect the
highest winds for a system moving north or northwest, were between
25 and 30 kt in both passes. Subjective Dvorak intensity estimates
were 30 kt and 25 kt from TAFB and SAB, respectively, at 00Z. It is
possible that the cyclone briefly had tropical-storm-strength winds
at one point, but given the observed warming of cloud tops since
00Z, the intensity is maintained at 30 kt for this advisory.

There is no real change to the forecast reasoning. The depression is
moving northwestward and a turn toward the west-northwest is
expected later today as it moves around a larger cyclonic gyre.
Conditions do not appear to be favorable for any strengthening, and
the dynamical models indicate that deep convection will dissipate
later today due to cool underlying SSTs and a drier surrounding
environment. The NHC track and intensity forecast is based on the
TVCA and IVCN consensus aids and has not been changed significantly
from the previous advisory.


FORECAST POSITIONS AND MAX WINDS

INIT 01/0300Z 17.1N 21.1W 30 KT 35 MPH
12H 01/1200Z 18.4N 22.5W 30 KT 35 MPH
24H 02/0000Z 19.3N 25.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 02/1200Z 20.0N 28.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 03/0000Z...DISSIPATED

$$
Forecaster Zelinsky

[cycloneye]

Tropical Depression Ten Discussion Number 3
NWS National Hurricane Center Miami FL AL102020
800 AM CVT Sat Aug 01 2020

Satellite images indicate that only a small area of deep convection
remains with the depression, and the center is partially exposed on
the southeastern edge of the thunderstorms. The initial wind speed
is kept 30 kt based on persistence. It seems like the chance for
the depression to become a tropical storm has passed with it now
moving over cooler waters into a drier air mass. Thus weakening is
forecast, and the system will likely degenerate into a remnant low
later today.

The depression continues moving northwestward, and that course
should persist today before turning towards the west-northwest
around a larger cyclonic gyre on Sunday. A slight northward
adjustment has been made to the forecast, a bit south of the GFS
model. All of the model guidance dissipate the small low within 36
hours, so this is indicated in the new forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 01/0900Z 17.8N 21.6W 30 KT 35 MPH
12H 01/1800Z 19.2N 23.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
24H 02/0600Z 20.5N 26.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 02/1800Z...DISSIPATED

$$
Forecaster Blake

[cycloneye]

Tropical Depression Ten Discussion Number 4
NWS National Hurricane Center Miami FL AL102020
200 PM CVT Sat Aug 01 2020

The center of the depression is mostly exposed this morning with
deep convection remaining only over the northwest portion of the
circulation. A recent ASCAT overpass showed a small area of
winds of 20 to 25 kt in the northern semicircle. Based on this
data, the initial intensity has been lowered to 25 kt. The
persistent convection has likely bought a little more time for
the depression to survive. However, the cyclone is forecast to
remain over SSTs of about 24 to 25 C for the next day or so. This
should cause the convection to gradually decrease, causing the
depression to become a remnant low by tonight. An alternative
scenario is that the low could open into a trough before the
convection dissipates.

The depression is moving northwest at around 12 kt. A turn to the
west-northwest is expected later today as the cyclone pivots around
a large mid-level gyre to its southwest. This west-northwest motion
should continue until the system dissipates.


FORECAST POSITIONS AND MAX WINDS

INIT 01/1500Z 18.6N 22.2W 25 KT 30 MPH
12H 02/0000Z 19.8N 23.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
24H 02/1200Z...DISSIPATED

$$
Forecaster Latto

[cycloneye]

Tropical Depression Ten Discussion Number 5
NWS National Hurricane Center Miami FL AL102020
800 PM CVT Sat Aug 01 2020

The depression is barely a tropical cyclone. Most of the deep
convection from the burst earlier in the day has now dissipated and
the circulation appears to be losing definition. The initial
intensity is held at 25 kt based on the ASCAT data from several
hours ago. Since the cyclone is over cool waters and in a dry
environment, significant deep convection is unlikely to return.
Therefore, the depression will likely become a remnant low tonight
and open into a trough shortly thereafter.

The weak and shallow system has turned to the left recently, with
the latest initial motion estimated to be 305/11 kt. A general
west-northwest motion is expected until the system dissipates a
couple of hundred miles north of the northern-most Cabo Verde
Islands tonight or on Sunday.


FORECAST POSITIONS AND MAX WINDS

INIT 01/2100Z 19.2N 23.5W 25 KT 30 MPH
12H 02/0600Z 19.9N 25.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
24H 02/1800Z...DISSIPATED

$$
Forecaster Cangialosi

[cycloneye]

Remnants Of Ten Discussion Number 6
NWS National Hurricane Center Miami FL AL102020
200 AM CVT Sun Aug 02 2020

Scatterometer data around 2130 UTC confirmed that the system north
of the Cabo Verde islands no longer has a well-defined center. The
scatterometer data showed that the southwest semicircle of the
system consists of only light and variable winds, and the strongest
winds associated with the system have decreased to around 20 kt. The
system lacks deep convection and a combination of cool underlying
water and a dry surrounding environment will prevent regeneration.
This is the last NHC advisory on this system.


FORECAST POSITIONS AND MAX WINDS

INIT 02/0300Z 19.5N 25.0W 20 KT 25 MPH...REMNANTS OF TEN
12H 02/1200Z...DISSIPATED

$$
Forecaster Zelinsky