BULLETIN
Tropical Depression Sixteen Advisory Number 1
NWS National Hurricane Center Miami FL AL162021
1100 PM AST Sat Sep 18 2021
...TROPICAL DEPRESSION FORMS EAST OF THE NORTHERN LEEWARD ISLANDS...
SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.4N 53.1W
ABOUT 670 MI...1080 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES
WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.
Interests in the northern Leeward Islands, Virgin Islands, and
Puerto Rico should monitor the progress of this system.
DISCUSSION AND OUTLOOK
----------------------
At 1100 PM AST (0300 UTC), the center of Tropical Depression Sixteen
was located near latitude 16.4 North, longitude 53.1 West. The
depression is moving toward the west-northwest near 14 mph (22 km/h)
and this motion is expected to continue during the next few days.
On the forecast track, the depression is expected to pass to the
north of the northern Leeward Islands on Monday and Tuesday.
Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Some strengthening is forecast, and the depression is expected to
become a tropical storm on Sunday.
The estimated minimum central pressure is 1008 mb (29.77 inches).
HAZARDS AFFECTING LAND
----------------------
RAINFALL: The outer bands of the depression could produce rainfall
totals of 1 to 3 inches across portions of the northern Leeward
Islands, including the Virgin Islands, as well as Puerto Rico later
Sunday through Tuesday. This rainfall may lead to areas of urban and
small stream flooding.
SURF: Swells generated by the depression are expected to reach the
northern Leeward Islands Sunday night and Monday. These swells
could cause life-threatening surf and rip current conditions.
Please consult products from your local weather office.
NEXT ADVISORY
-------------
Next complete advisory at 500 AM AST.
$$
Forecaster Cangialosi
Tropical Depression Sixteen Discussion Number 1
NWS National Hurricane Center Miami FL AL162021
1100 PM AST Sat Sep 18 2021
Satellite images and surface observations indicate that the area of
low pressure that NHC has been monitoring to the east of the
northern Leeward Islands now has a well-defined center and
sufficiently organized deep convection to be classified a tropical
depression. The depression has a small area of deep convection near
its center and curved bands on its north and east sides. The
initial intensity is estimated to be 30 kt, but this is a little
below the latest Dvorak classifications and could be conservative.
The depression is moving west-northwestward at 12 kt. The cyclone
should continue west-northwestward at about the same pace during the
next few days as it moves in the flow on the southwest side of a
mid-level ridge. After that time, the ridge is expected to break
down and the steering currents are forecast to become weak. Not
surprisingly, the spread in the models increases around that time,
but most of the solutions show a slow turn toward the north toward
broad troughing associated with Post-Tropical Cyclone Odette. The
GFS is on the southern side of the guidance envelope and the ECMWF
on the northern side. The NHC track forecast lies between those
models near the consensus aids.
Some strengthening seems possible during the next 12 to 24 hours and
the system is expected to become a tropical storm during that time
frame. However, an increase in southerly and then southwesterly
vertical wind shear should cause the system to level off in strength
from 24 hours through the end of the forecast period. The models
are in fairly good agreement on this overall scenario, and the NHC
intensity forecast is in line with the majority of the guidance.
Based on the track, intensity, and wind radii forecast, no tropical
storm watches or warnings are required for the northern Leeward
Islands, Virgin Islands or Puerto Rico. However, interests there
should monitor the progress of the system as locally heavy rain is
possible on Monday and Tuesday when it is expected to pass to the
north of the area.
FORECAST POSITIONS AND MAX WINDS
INIT 19/0300Z 16.4N 53.1W 30 KT 35 MPH
12H 19/1200Z 17.3N 54.8W 35 KT 40 MPH
24H 20/0000Z 18.5N 57.3W 40 KT 45 MPH
36H 20/1200Z 19.4N 59.8W 40 KT 45 MPH
48H 21/0000Z 20.3N 61.9W 35 KT 40 MPH
60H 21/1200Z 21.3N 64.1W 35 KT 40 MPH
72H 22/0000Z 22.3N 65.5W 35 KT 40 MPH
96H 23/0000Z 24.4N 66.5W 35 KT 40 MPH
120H 24/0000Z 26.3N 66.2W 35 KT 40 MPH
$$
Forecaster Cangialosi
Tropical Depression Sixteen Advisory Number 1
NWS National Hurricane Center Miami FL AL162021
1100 PM AST Sat Sep 18 2021
...TROPICAL DEPRESSION FORMS EAST OF THE NORTHERN LEEWARD ISLANDS...
SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.4N 53.1W
ABOUT 670 MI...1080 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES
WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.
Interests in the northern Leeward Islands, Virgin Islands, and
Puerto Rico should monitor the progress of this system.
DISCUSSION AND OUTLOOK
----------------------
At 1100 PM AST (0300 UTC), the center of Tropical Depression Sixteen
was located near latitude 16.4 North, longitude 53.1 West. The
depression is moving toward the west-northwest near 14 mph (22 km/h)
and this motion is expected to continue during the next few days.
On the forecast track, the depression is expected to pass to the
north of the northern Leeward Islands on Monday and Tuesday.
Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Some strengthening is forecast, and the depression is expected to
become a tropical storm on Sunday.
The estimated minimum central pressure is 1008 mb (29.77 inches).
HAZARDS AFFECTING LAND
----------------------
RAINFALL: The outer bands of the depression could produce rainfall
totals of 1 to 3 inches across portions of the northern Leeward
Islands, including the Virgin Islands, as well as Puerto Rico later
Sunday through Tuesday. This rainfall may lead to areas of urban and
small stream flooding.
SURF: Swells generated by the depression are expected to reach the
northern Leeward Islands Sunday night and Monday. These swells
could cause life-threatening surf and rip current conditions.
Please consult products from your local weather office.
NEXT ADVISORY
-------------
Next complete advisory at 500 AM AST.
$$
Forecaster Cangialosi
Tropical Depression Sixteen Discussion Number 1
NWS National Hurricane Center Miami FL AL162021
1100 PM AST Sat Sep 18 2021
Satellite images and surface observations indicate that the area of
low pressure that NHC has been monitoring to the east of the
northern Leeward Islands now has a well-defined center and
sufficiently organized deep convection to be classified a tropical
depression. The depression has a small area of deep convection near
its center and curved bands on its north and east sides. The
initial intensity is estimated to be 30 kt, but this is a little
below the latest Dvorak classifications and could be conservative.
The depression is moving west-northwestward at 12 kt. The cyclone
should continue west-northwestward at about the same pace during the
next few days as it moves in the flow on the southwest side of a
mid-level ridge. After that time, the ridge is expected to break
down and the steering currents are forecast to become weak. Not
surprisingly, the spread in the models increases around that time,
but most of the solutions show a slow turn toward the north toward
broad troughing associated with Post-Tropical Cyclone Odette. The
GFS is on the southern side of the guidance envelope and the ECMWF
on the northern side. The NHC track forecast lies between those
models near the consensus aids.
Some strengthening seems possible during the next 12 to 24 hours and
the system is expected to become a tropical storm during that time
frame. However, an increase in southerly and then southwesterly
vertical wind shear should cause the system to level off in strength
from 24 hours through the end of the forecast period. The models
are in fairly good agreement on this overall scenario, and the NHC
intensity forecast is in line with the majority of the guidance.
Based on the track, intensity, and wind radii forecast, no tropical
storm watches or warnings are required for the northern Leeward
Islands, Virgin Islands or Puerto Rico. However, interests there
should monitor the progress of the system as locally heavy rain is
possible on Monday and Tuesday when it is expected to pass to the
north of the area.
FORECAST POSITIONS AND MAX WINDS
INIT 19/0300Z 16.4N 53.1W 30 KT 35 MPH
12H 19/1200Z 17.3N 54.8W 35 KT 40 MPH
24H 20/0000Z 18.5N 57.3W 40 KT 45 MPH
36H 20/1200Z 19.4N 59.8W 40 KT 45 MPH
48H 21/0000Z 20.3N 61.9W 35 KT 40 MPH
60H 21/1200Z 21.3N 64.1W 35 KT 40 MPH
72H 22/0000Z 22.3N 65.5W 35 KT 40 MPH
96H 23/0000Z 24.4N 66.5W 35 KT 40 MPH
120H 24/0000Z 26.3N 66.2W 35 KT 40 MPH
$$
Forecaster Cangialosi