ATL: DOLLY - Advisories

[cycloneye]

BULLETIN
Subtropical Depression Four Advisory Number 1
NWS National Hurricane Center Miami FL AL042020
500 PM AST Mon Jun 22 2020

...SUBTROPICAL DEPRESSION FORMS WELL OFFSHORE OF THE U.S. EAST
COAST...
...FORECAST TO MOVE AWAY FROM LAND...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...38.2N 65.7W
ABOUT 310 MI...495 KM SE OF NANTUCKET MASSACHUSETTS
ABOUT 455 MI...730 KM SSW OF HALIFAX NOVA SCOTIA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...ENE OR 75 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...1009 MB...29.80 INCHES


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


DISCUSSION AND OUTLOOK
----------------------
At 500 PM AST (2100 UTC), the center of Subtropical Depression Four
was located near latitude 38.2 North, longitude 65.7 West. The
subtropical depression is moving toward the east-northeast near 9
mph (15 km/h) and this motion is forecast to continue through
tonight. A motion toward the northeast is expected on Tuesday and
Wednesday.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Some slight strengthening is possible tonight and early Tuesday,
and the subtropical depression could briefly become a subtropical
storm. Slow weakening is expected to begin by Tuesday afternoon or
evening.

The estimated minimum central pressure is 1009 mb (29.80 inches).


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


NEXT ADVISORY
-------------
Next complete advisory at 1100 PM AST.

$$
Forecaster Stewart



Subtropical Depression Four Discussion Number 1
NWS National Hurricane Center Miami FL AL042020
500 PM AST Mon Jun 22 2020

The non-tropical low pressure system that the National Hurricane
Center has been following for the past couple of days off of the
U.S. east coast has developed enough organized convection near the
center to be classified as subtropical depression. The subtropical
status is due to the low-level circulation center being co-located
beneath an upper-level cold low as seen in water vapor imagery. The
initial intensity of 30 kt is based on earlier ASCAT wind data
indicating numerous surface wind vectors of 26-28 kt in the
southern semicircle, along with a TAFB subtropical satellite
classification of ST1.5/25-30 kt.

The initial motion estimate is 075/08 kt. Subtropical Depression
Four is located north of a deep-layer ridge and is being influenced
by weak westerly mid- to upper-level flow. The cyclone is forecast
by all of the global and regional models to move east-northeastward
tonight and then turn northeastward on Tuesday. A northeastward
motion at a faster forward speed is expected Tuesday night through
Thursday when the system is forecast to be located over the cold
waters of the far north Atlantic. The cyclone should be absorbed by
a larger extratropical low or dissipate on Thursday. The NHC track
forecast is close to a blend of the simple consensus aids TVCN and
GFEX and the NOAA-HCCA corrected consensus.

The cyclone is beginning to move over a ridge of higher SSTs of
26.0-26.5 deg C in the northern extent of the Gulf Stream. The
forecast track takes the subtropical depression down the length of
the axis of warmer water during the next 12-18 h, so there is the
potential for the cyclone to become a subtropical storm during that
time, especially given the large pool of cold air aloft, with 200-mb
temperatures of near -58 deg C and 500-mb temperatures of about -10
deg C which is creating a lot of instability. After the system moves
off of the warm ridge and into sharply cooler water around 36 hours
or so, gradual weakening is expected, with transition to an
extratropical cyclone forecast by 48 hours. The NHC intensity
forecast closely follows a blend of the consensus models ICON, IVCN,
and HCCA.

FORECAST POSITIONS AND MAX WINDS

INIT 22/2100Z 38.2N 65.7W 30 KT 35 MPH
12H 23/0600Z 38.5N 64.0W 35 KT 40 MPH
24H 23/1800Z 39.0N 62.0W 30 KT 35 MPH
36H 24/0600Z 40.5N 59.3W 30 KT 35 MPH
48H 24/1800Z 42.5N 56.7W 30 KT 35 MPH...POST-TROP/EXTRATROP
60H 25/0600Z 45.0N 53.3W 30 KT 35 MPH...POST-TROP/EXTRATROP
72H 25/1800Z 47.8N 50.4W 30 KT 35 MPH...POST-TROP/EXTRATROP
96H 26/1800Z...DISSIPATED

$$
Forecaster Stewart

[cycloneye]

BULLETIN
Subtropical Depression Four Advisory Number 2
NWS National Hurricane Center Miami FL AL042020
1100 PM AST Mon Jun 22 2020

...SUBTROPICAL DEPRESSION MOVING EAST-NORTHEASTWARD AWAY FROM
LAND...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...38.7N 64.6W
ABOUT 335 MI...535 KM ESE OF NANTUCKET MASSACHUSETTS
ABOUT 410 MI...660 KM S OF HALIFAX NOVA SCOTIA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...ENE OR 60 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...1009 MB...29.80 INCHES


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


DISCUSSION AND OUTLOOK
----------------------
At 1100 PM AST (0300 UTC), the center of Subtropical Depression Four
was located near latitude 38.7 North, longitude 64.6 West. The
depression is moving toward the east-northeast near 10 mph (17 km/h)
and a turn toward the northeast with some increase in forward speed
is expected during the next 48 hours.

Maximum sustained winds remain near 35 mph (55 km/h) with higher
gusts. Some slight strengthening is possible early Tuesday, and
the subtropical depression could briefly become a subtropical
storm. Slow weakening is expected to begin by Tuesday afternoon or
evening.

The estimated minimum central pressure is 1009 mb (29.80 inches).


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


NEXT ADVISORY
-------------
Next complete advisory at 500 AM AST.

$$
Forecaster Pasch




Subtropical Depression Four Discussion Number 2
NWS National Hurricane Center Miami FL AL042020
1100 PM AST Mon Jun 22 2020

The cyclone has little or no deep convection near its center, and
remains situated beneath an upper-level low. Therefore, the system
is still a subtropical cyclone and the intensity is kept at 30 kt
in agreement with the most recent satellite classification from
TAFB. The 30-kt intensity was also supported by recent
scatterometer data. There is a small window of opportunity for
strengthening since the system should remain over a relatively warm
Gulf Stream eddy for 12 hours or so. Thereafter, a weakening trend
is expected to begin and the system should make the transition to
an extratropical cyclone over cooler waters in 36 hours or sooner.
The global models indicate that the system should open up into a
trough in a couple of days so the official forecast shows
dissipation by 72 hours. It would not be surprising if the system
meets its demise sooner than that. The official intensity forecast
is similar to the latest decay-SHIPS guidance.

The motion continues east-northeastward, or 060/9 kt. Over the
next few days, the cyclone should remain embedded in a branch of
west-southwesterlies that is split off from the main mid-latitude
flow. There is good agreement in the track guidance that the
system will turn northeastward with some acceleration during the
next 48-60 hours. The official track forecast is similar to the
previous one, and is also close to the dynamical model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT 23/0300Z 38.7N 64.6W 30 KT 35 MPH
12H 23/1200Z 39.2N 62.9W 35 KT 40 MPH
24H 24/0000Z 40.3N 60.6W 30 KT 35 MPH
36H 24/1200Z 42.0N 58.5W 30 KT 35 MPH...POST-TROP/EXTRATROP
48H 25/0000Z 44.0N 55.5W 25 KT 30 MPH...POST-TROP/EXTRATROP
60H 25/1200Z 46.0N 52.0W 25 KT 30 MPH...POST-TROP/EXTRATROP
72H 26/0000Z...DISSIPATED

$$
Forecaster Pasch

[cycloneye]

BULLETIN
Subtropical Depression Four Advisory Number 3
NWS National Hurricane Center Miami FL AL042020
500 AM AST Tue Jun 23 2020

...SUBTROPICAL DEPRESSION MOVING NORTHEASTWARD WITH LITTLE CHANGE
IN STRENGTH...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...39.3N 63.4W
ABOUT 365 MI...590 KM S OF HALIFAX NOVA SCOTIA
ABOUT 730 MI...1170 KM SW OF CAPE RACE NEWFOUNDLAND
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NE OR 55 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES


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


DISCUSSION AND OUTLOOK
----------------------
At 500 AM AST (0900 UTC), the center of Subtropical Depression Four
was located near latitude 39.3 North, longitude 63.4 West. The
depression is moving toward the northeast near 13 mph (20 km/h), and
this motion is expected to continue for next couple of days with
some increase in forward speed.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Little change in strength is forecast during the next day or so,
with the system likely weakening and transitioning into a
post-tropical cyclone on Wednesday.

The estimated minimum central pressure is 1008 mb (29.77 inches).


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


NEXT ADVISORY
-------------
Next complete advisory at 1100 AM AST.

$$
Forecaster Blake




Subtropical Depression Four Discussion Number 3
NWS National Hurricane Center Miami FL AL042020
500 AM AST Tue Jun 23 2020

Deep convection has increased during the past several hours in the
diurnal convective maximum, although there isn't much organization
to the activity. The depression is situated beneath an
upper-level low, and the system has a large radius-of-maximum
winds, so it is still subtropical. The initial intensity is 30 kt,
based on persistence from the earlier scatterometer data. While it
is possible the depression could become a storm later today,
rapidly cooling SSTs should cause the system to weaken on
Wednesday, and open up into a trough on or before Thursday.

The depression is moving northeastward at about 11 kt. There
is good agreement in the track guidance that the system will
continue moving in the same general direction with some
acceleration during the next couple of days, embedded within the
mid-latitude southwesterlies. The new track forecast has been
nudged slightly to the north of the previous one, close to the NOAA
corrected-consensus model.


FORECAST POSITIONS AND MAX WINDS

INIT 23/0900Z 39.3N 63.4W 30 KT 35 MPH
12H 23/1800Z 40.0N 61.7W 30 KT 35 MPH
24H 24/0600Z 41.4N 59.5W 30 KT 35 MPH
36H 24/1800Z 43.3N 56.9W 25 KT 30 MPH...POST-TROP/EXTRATROP
48H 25/0600Z 45.3N 53.5W 25 KT 30 MPH...POST-TROP/EXTRATROP
60H 25/1800Z...DISSIPATED

$$
Forecaster Blake

[cycloneye]

BULLETIN
Subtropical Depression Four Advisory Number 4
NWS National Hurricane Center Miami FL AL042020
1100 AM AST Tue Jun 23 2020

...SUBTROPICAL DEPRESSION HEADING FOR COLDER WATERS...
...FORECAST TO BECOME A REMNANT LOW ON WEDNESDAY...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...39.5N 62.1W
ABOUT 360 MI...580 KM SSE OF HALIFAX NOVA SCOTIA
ABOUT 670 MI...1080 KM SW OF CAPE RACE NEWFOUNDLAND
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...ENE OR 65 DEGREES AT 13 MPH...20 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 1100 AM AST (1500 UTC), the center of Subtropical Depression Four
was located near latitude 39.5 North, longitude 62.1 West. The
depression is moving toward the east-northeast near 13 mph (20
km/h). A turn toward the northeast with an increase in forward
speed is expected tonight and on Wednesday.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Little change in strength is forecast during the next day or two,
but the depression is expected to degenerate into a remnant low on
Wednesday and dissipate by early Thursday.

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


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


NEXT ADVISORY
-------------
Next complete advisory at 500 PM AST.

$$
Forecaster Berg



Subtropical Depression Four Discussion Number 4
NWS National Hurricane Center Miami FL AL042020
1100 AM AST Tue Jun 23 2020

GOES-16 visible satellite imagery shows that the depression's
circulation has become better defined since yesterday, and the
center is exposed just to the north of a band of convection mainly
located within the southern semicircle. This convection is aligned
along the Gulf Stream current, where instability is greatest, and
the system appears a little more tropical than yesterday. However,
the depression is still collocated with an upper-level low, and it
will therefore retain the subtropical designation. The initial
intensity remains 30 kt based on a ST1.5/25-30 kt classification
from TAFB. A partial 1323 UTC ASCAT-B scatterometer pass showed
winds near 30 kt to the southeast of the center, and we'll continue
to monitor additional scatterometer data to see if there are winds
any higher than that.

The initial motion is still 11 kt, but the heading has turned
east-northeastward at 65 degrees. The depression is forecast to
turn back toward the northeast by this evening and begin
accelerating on Wednesday within the prevailing mid-latitude flow.
This track will take the system over increasingly colder water,
placing it over sea surface temperatures less than 20 degrees
Celsius by early Wednesday. Those ocean temperatures will make it
difficult to support deep convection, and the updated NHC forecast
now calls for the system to degenerate to a remnant low in 24 hours.
Dissipation has been moved to 48 hours, although global model
fields indicate that the system could open up into a trough by 36
hours before it moves past Newfoundland.

The Ocean Prediction Center has provided 12-ft sea radii in the
southern semicircle based on recent AltiKa and Jason-3 altimeter
data.


FORECAST POSITIONS AND MAX WINDS

INIT 23/1500Z 39.5N 62.1W 30 KT 35 MPH
12H 24/0000Z 40.6N 60.3W 30 KT 35 MPH
24H 24/1200Z 42.3N 58.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 25/0000Z 44.2N 55.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 25/1200Z...DISSIPATED

$$
Forecaster Berg

[cycloneye]

Tropical Storm Dolly Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL042020
1215 PM AST Tue Jun 23 2020

...DOLLY FORMS OVER THE NORTH ATLANTIC...

Recent satellite-derived wind data indicate that Subtropical
Depression Four has strengthened, and maximum sustained winds are
now 45 mph (75 km/h) with higher gusts. In addition, the wind
field has contracted, and the system has made a transition to a
tropical storm.

A Special Advisory on Tropical Storm Dolly will be issued by 100 PM
AST (1700 UTC) to update the intensity forecast.


SUMMARY OF 1215 PM AST...1615 UTC...INFORMATION
----------------------------------------------
LOCATION...39.4N 61.9W
ABOUT 370 MI...595 KM SSE OF HALIFAX NOVA SCOTIA
ABOUT 660 MI...1065 KM SW OF CAPE RACE NEWFOUNDLAND
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...ENE OR 65 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES

$$
Forecaster Berg/Brown

[cycloneye]

BULLETIN
Tropical Storm Dolly Special Advisory Number 5
NWS National Hurricane Center Miami FL AL042020
100 PM AST Tue Jun 23 2020

...DOLLY FORMS OVER THE NORTH ATLANTIC...
...STILL EXPECTED TO BECOME POST-TROPICAL ON WEDNESDAY...


SUMMARY OF 100 PM AST...1700 UTC...INFORMATION
----------------------------------------------
LOCATION...39.4N 61.7W
ABOUT 370 MI...600 KM SSE OF HALIFAX NOVA SCOTIA
ABOUT 665 MI...1070 KM SW OF CAPE RACE NEWFOUNDLAND
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...ENE OR 65 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES


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


DISCUSSION AND OUTLOOK
----------------------
At 100 PM AST (1700 UTC), the center of Tropical Storm Dolly was
located near latitude 39.4 North, longitude 61.7 West. Dolly is
moving toward the east-northeast near 13 mph (20 km/h). A turn
toward the northeast with an increase in forward speed is expected
tonight and on Wednesday.

Satellite-derived wind data indicate that maximum sustained winds
have increased to near 45 mph (75 km/h) with higher gusts.
Weakening is forecast during the next day or two as Dolly moves
over colder waters, and the system is expected to become
post-tropical on Wednesday. The low should then dissipate by early
Thursday.

Tropical-storm-force winds extend outward up to 70 miles (110 km)
to the south of the center.

The estimated minimum central pressure is 1002 mb (29.59 inches).


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


NEXT ADVISORY
-------------
Next complete advisory at 500 PM AST.

$$
Forecaster Berg

Tropical Storm Dolly Special Discussion Number 5
NWS National Hurricane Center Miami FL AL042020
100 PM AST Tue Jun 23 2020

A 1348 UTC ASCAT-A scatterometer pass, arriving just after the
previous advisory was issued, indicates that the cyclone is
producing winds of 35-40 kt in its southern semicircle. In
addition, the radius of maximum winds has contracted to about 40 n
mi. This, along with the current convective pattern, suggests that
the system has made a transition from a subtropical to a tropical
cyclone, and it has been designated as Tropical Storm Dolly.

This Special Advisory package is being issued to update the
intensity and wind radii forecasts, increasing Dolly's maximum
winds at each forecast time by 5 kt during the next 24 hours. The
forecast track and status changes are the same as in the previous
advisory.

FORECAST POSITIONS AND MAX WINDS

INIT 23/1700Z 39.4N 61.7W 40 KT 45 MPH
12H 24/0000Z 40.6N 60.3W 35 KT 40 MPH
24H 24/1200Z 42.3N 58.1W 30 KT 35 MPH...POST-TROP/REMNT LOW
36H 25/0000Z 44.2N 55.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 25/1200Z...DISSIPATED

$$
Forecaster Berg

[cycloneye]

BULLETIN
Tropical Storm Dolly Advisory Number 6
NWS National Hurricane Center Miami FL AL042020
500 PM AST Tue Jun 23 2020

...DOLLY BEGINNING TO MOVE AWAY FROM THE GULF STREAM CURRENT...
...FORECAST TO BECOME A REMNANT LOW ON WEDNESDAY...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...40.1N 61.1W
ABOUT 335 MI...540 KM SSE OF HALIFAX NOVA SCOTIA
ABOUT 605 MI...975 KM SW OF CAPE RACE NEWFOUNDLAND
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...ENE OR 60 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES


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


DISCUSSION AND OUTLOOK
----------------------
At 500 PM AST (2100 UTC), the center of Tropical Storm Dolly was
located near latitude 40.1 North, longitude 61.1 West. Dolly is
moving toward the east-northeast near 12 mph (19 km/h). A turn
toward the northeast with an increase in forward speed is expected
tonight and on Wednesday.

Maximum sustained winds are near 45 mph (75 km/h) with higher gusts.
Weakening is forecast as Dolly moves over colder waters, and the
system is expected to become post-tropical on Wednesday. The
remnant low should then dissipate by early Thursday.

Tropical-storm-force winds extend outward up to 70 miles (110 km)
to the south of the center.

The estimated minimum central pressure is 1002 mb (29.59 inches).


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


NEXT ADVISORY
-------------
Next complete advisory at 1100 PM AST.

$$
Forecaster Berg



Tropical Storm Dolly Discussion Number 6
NWS National Hurricane Center Miami FL AL042020
500 PM AST Tue Jun 23 2020

Dolly's structure has continued to improve somewhat during the day
with convective banding now extending around the eastern and
northern side of the circulation. While water vapor imagery
indicates that an upper-level low is still in the vicinity of
Dolly, that feature is displaced from the cyclone a bit, with some
anticyclonic outflow noted in the cirrus canopy. This
structure further supports the analysis of Dolly's transition to a
tropical storm. For intensity, there is a wide range among
satellite estimates, with TAFB and SAB ranging from 25-35 kt and
UW-CIMSS ADT and SATCON estimates between 45-50 kt. The initial
intensity will remain 40 kt on this advisory, matching what was
shown by the earlier scatterometer data.

Dolly continues to move east-northeastward with an initial motion
of 060/10 kt. Strengthening mid-latitude southwesterly flow is
expected to cause Dolly to turn northeastward and begin
accelerating tonight into Wednesday, and the track guidance is in
good agreement on the future path and speed of the storm. Dolly's
future track will take it over much colder waters and into a
higher-shear environment over the next day or so, which should
cause the cyclone to degenerate into a remnant low on Wednesday.
Dissipation is still shown at 48 hours, but global models fields
indicate that the circulation could open up before then as the
system nears the southeastern tip of Newfoundland.


FORECAST POSITIONS AND MAX WINDS

INIT 23/2100Z 40.1N 61.1W 40 KT 45 MPH
12H 24/0600Z 41.2N 59.4W 35 KT 40 MPH
24H 24/1800Z 43.1N 56.9W 30 KT 35 MPH...POST-TROP/REMNT LOW
36H 25/0600Z 45.0N 53.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 25/1800Z...DISSIPATED

$$
Forecaster Berg

[cycloneye]

BULLETIN
Tropical Storm Dolly Advisory Number 7
NWS National Hurricane Center Miami FL AL042020
1100 PM AST Tue Jun 23 2020

..DOLLY LIKELY TO BECOME A POST-TROPICAL REMNANT LOW ON WEDNESDAY...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...40.5N 60.3W
ABOUT 560 MI...900 KM SW OF CAPE RACE NEWFOUNDLAND
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...ENE OR 60 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES


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


DISCUSSION AND OUTLOOK
----------------------
At 1100 PM AST (0300 UTC), the center of Tropical Storm Dolly was
located near latitude 40.5 North, longitude 60.3 West. Dolly is
moving toward the east-northeast near 10 mph (17 km/h). A turn
toward the northeast with an increase in forward speed is expected
on Wednesday.

Maximum sustained winds have decreased to near 40 mph (65 km/h)
with higher gusts. Continued weakening is forecast as Dolly moves
over colder waters, and the system is expected to become
post-tropical on Wednesday. The remnant low should then dissipate
by Thursday.

Tropical-storm-force winds extend outward up to 70 miles (110 km)
from the center.

The estimated minimum central pressure is 1004 mb (29.65 inches).


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


NEXT ADVISORY
-------------
Next complete advisory at 500 AM AST.

$$
Forecaster Pasch


Tropical Storm Dolly Discussion Number 7
NWS National Hurricane Center Miami FL AL042020
1100 PM AST Tue Jun 23 2020

Dolly's deep convection is diminishing as the cyclone begins to
move over colder waters to the north of the Gulf Stream. Given
the decreased convection, it is assumed that the circulation is
gradually spinning down and the current intensity is therefore
estimated to be near 35 kt. This is also consistent with data from
a recent scatterometer overpass. Within 24 hours, the system will
be moving over SSTs of around 15 deg C, and the cyclone should have
degenerated into remnant low devoid of significant convection. The
global models forecast the system to open up into a trough in 36
hours or so and the official forest calls for dissipation by 48
hours, if not sooner.

The cyclone continues to move east-northeastward, or around
060/9 kt. There is no change to the track forecast reasoning,
Dolly is expected to turn northeastward with an increase in forward
speed as it moves with the southwesterly mid-level flow to the
southeast of the main branch of mid-latitude westerlies. The
official track forecast lies close to the previous one and is on
top of the latest dynamical model consensus, TVCA, track.

FORECAST POSITIONS AND MAX WINDS

INIT 24/0300Z 40.5N 60.3W 35 KT 40 MPH
12H 24/1200Z 41.8N 58.4W 30 KT 35 MPH
24H 25/0000Z 43.9N 55.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
36H 25/1200Z 45.8N 52.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 26/0000Z...DISSIPATED

$$
Forecaster Pasch

[cycloneye]

Tropical Depression Dolly Discussion Number 8
NWS National Hurricane Center Miami FL AL042020
500 AM AST Wed Jun 24 2020

Deep convection associated with Dolly has become limited and it
is confined to an area well to the east of the exposed center.
This degraded structure is because the cyclone is now over very
cool 22 degree C waters. ASCAT data from several hours ago
indicated that maximum winds have fallen below tropical storm force,
and the initial intensity is lowered to 30 kt based on that data and
the latest Dvorak estimate from TAFB. This makes Dolly a tropical
depression, and the system is well on its way to becoming a remnant
low. Since the depression is headed for even cooler waters,
continued weakening is expected and Dolly will likely become a
remnant low later today. Dissipation is now expected to occur by
36 hours, but the global models suggest that it could occur even
sooner than that.

The tropical depression is moving northeastward at 10 kt. A faster
northeastward motion on the north side of a subtropical ridge is
expected until the system dissipates on Thursday. The NHC track
forecast lies near the middle of the tightly clustered model
solutions.


FORECAST POSITIONS AND MAX WINDS

INIT 24/0900Z 41.7N 59.0W 30 KT 35 MPH
12H 24/1800Z 43.1N 57.1W 30 KT 35 MPH...POST-TROP/REMNT LOW
24H 25/0600Z 45.1N 53.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 25/1800Z...DISSIPATED

$$
Forecaster Cangialosi

[cycloneye]

BULLETIN
Post-Tropical Cyclone Dolly Advisory Number 9
NWS National Hurricane Center Miami FL AL042020
1100 AM AST Wed Jun 24 2020

...DOLLY BECOMES A POST-TROPICAL REMNANT LOW...
...THIS IS THE LAST ADVISORY...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...42.5N 57.8W
ABOUT 370 MI...595 KM SW OF CAPE RACE NEWFOUNDLAND
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NE OR 45 DEGREES AT 16 MPH...26 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 1100 AM AST (1500 UTC), the center of Post-Tropical Cyclone Dolly
was located near latitude 42.5 North, longitude 57.8 West. The
post-tropical cyclone is moving toward the northeast near 16 mph (26
km/h) and this general motion is expected to continue through
tonight.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Gradual weakening is expected, and Post-Tropical Cyclone Dolly is
expected to dissipate by Thursday morning.

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


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


NEXT ADVISORY
-------------
This is the last public advisory issued by the National Hurricane
Center on this system. Additional information on this system can be
found in High Seas Forecasts issued by the National Weather Service,
under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and online at
ocean.weather.gov/shtml/NFDHSFAT1.php

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Forecaster Latto



Post-Tropical Cyclone Dolly Discussion Number 9
NWS National Hurricane Center Miami FL AL042020
1100 AM AST Wed Jun 24 2020

The center of Dolly has been exposed since last night, and any
remaining convection has been displaced well to the system's south.
The circulation is now traversing over waters below 20 degrees C,
and therefore is not anticipated that any deep convection will
return to the post-tropical remnant low. The initial intensity of 30
kt is based on an overnight ASCAT overpass. The low is forecast to
gradually spin down through tonight and will likely open to a
surface trough sometime on Thursday as it continues to move
northeastward at around 15 kt.

This is the last NHC advisory on this system.


FORECAST POSITIONS AND MAX WINDS

INIT 24/1500Z 42.5N 57.8W 30 KT 35 MPH...POST-TROPICAL
12H 25/0000Z 44.1N 55.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
24H 25/1200Z 45.9N 51.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 26/0000Z...DISSIPATED

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Forecaster Latto