BULLETIN
Tropical Depression One Advisory Number 1
NWS National Hurricane Center Miami FL AL012020
500 PM EDT Sat May 16 2020
...TROPICAL DEPRESSION FORMS OFF THE COAST OF EAST-CENTRAL
FLORIDA...
...TROPICAL STORM WATCH ISSUED FOR A PORTION OF THE NORTH CAROLINA
COAST...
SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...28.4N 78.6W
ABOUT 125 MI...200 KM E OF MELBOURNE FLORIDA
ABOUT 505 MI...810 KM SSW OF CAPE HATTERAS NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NNE OR 20 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
A Tropical Storm Watch has been issued for the North Carolina coast
from north of Surf City to Duck, including Pamlico and
Albemarle Sounds.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Watch is in effect for...
* New River Inlet to Duck NC
* Pamlico and Albemarle Sounds
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.
For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.
DISCUSSION AND OUTLOOK
----------------------
At 500 PM EDT (2100 UTC), the center of Tropical Depression One
was located near latitude 28.4 North, longitude 78.6 West. The
depression is moving toward the north-northeast near 13 mph (20
km/h) and this motion should continue during the next day or so.
After that time, a faster northeastward motion is expected. On
the forecast track, the depression is expected to move offshore,
but parallel to, the coast of Florida tonight, and then move near
or east of the coast of North Carolina on Monday.
Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Gradual strengthening is forecast, and the depression is expected
to become a tropical storm on Sunday.
The estimated minimum central pressure based on surface observations
and earlier aircraft reconnaissance data is 1008 mb (29.77 inches).
HAZARDS AFFECTING LAND
----------------------
WIND: Tropical storm conditions are possible within the watch
area by on Monday.
RAINFALL: The depression is expected to produce additional rain
accumulations of 1 to 2 inches over the central and northwest
Bahamas, and generally less than 1 inch over south Florida through
tonight. The depression is also expected to produce total rain
accumulations of 1 to 2 inches over coastal North Carolina Sunday
night and Monday.
SURF: Swells generated by the depression are affecting portions of
the east coast of central and northern Florida. These swells are
expected to spread northward during the next few days, and could
cause life-threatening surf and rip current conditions across much
of the U.S. southeast and mid-Atlantic coasts. Please consult
products from your local weather office.
NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM EDT.
Next complete advisory at 1100 PM EDT.
$$
Forecaster Cangialosi
Tropical Depression One Discussion Number 1
NWS National Hurricane Center Miami FL AL012020
500 PM EDT Sat May 16 2020
Satellite images, Doppler radar data, and surface observations
indicate that the low pressure system located just east of the coast
of central Florida has developed sufficient organization to now be
classified as a tropical depression. The low-level center is well
defined and deep convection has persisted near the center and in
bands on the east side of the circulation for the past several
hours. The cyclone is considered tropical instead of subtropical
because it has central deep convection and a relatively small radius
of maximum wind. The initial intensity is estimated to be 30 kt
based on data collected earlier today by the Air Force Hurricane
Hunters. Another aircraft is scheduled to investigate the system
this evening.
Based on satellite data and the earlier reconnaissance fixes, the
initial motion of the system is north-northeastward at 11 kt. A
continued north-northeastward motion at about the same forward speed
is expected during the next 24 hours or so, keeping the cyclone
offshore, but parallel to, the east coast of Florida. After that
time,
the model solutions begin to diverge and the details of the track
forecast become more complicated. The important features for the
future track of the depression appear to be a pair of mid- to
upper-level troughs currently over the central U.S. The specific
amplitude, timing, and location of those troughs will ultimately
result in how close to the coast of North Carolina this system gets.
The GFS and HWRF models are on the left side of the guidance and
bring the system inland or along the coast, while the ECMWF and
UKMET models show an offshore track. The NHC track forecast splits
the difference of these solutions, and lies close to the various
consensus models, which usually perform best. It should be noted
that forecast uncertainty is typically larger for weak systems like
this one.
The system should gradually strengthen during the next couple of
days as it remains over the Gulf Stream current and in relatively
low wind shear conditions. However, the surrounding air mass is not
particularly moist, so that and the marginally warm SSTs should
limit significant intensification. The NHC intensity forecast calls
for the system to become a tropical storm tonight or on Sunday with
continued slow strengthening as it nears the North Carolina coast.
Extratropical transition should occur in about 3 days, or sooner.
The NHC intensity forecast generally lies roughly near the middle of
the guidance envelope.
Key Messages:
1. A tropical storm watch has been issued for a portion of the
North Carolina coast. Tropical-storm-force winds and heavy rains
are possible there on Monday.
2. Dangerous coastal surf conditions and rip currents are expected
to spread northward from Florida to the mid-Atlantic states during
the next few days. See products from your local National Weather
Service for more details.
FORECAST POSITIONS AND MAX WINDS
INIT 16/2100Z 28.4N 78.6W 30 KT 35 MPH
12H 17/0600Z 29.7N 78.0W 35 KT 40 MPH
24H 17/1800Z 31.4N 77.4W 35 KT 40 MPH
36H 18/0600Z 33.0N 76.6W 40 KT 45 MPH
48H 18/1800Z 35.2N 74.8W 45 KT 50 MPH
60H 19/0600Z 37.1N 72.3W 50 KT 60 MPH
72H 19/1800Z 38.0N 70.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
96H 20/1800Z 38.0N 68.5W 45 KT 50 MPH...POST-TROP/EXTRATROP
120H 21/1800Z...DISSIPATED
$$
Forecaster Cangialosi
Tropical Depression One Advisory Number 1
NWS National Hurricane Center Miami FL AL012020
500 PM EDT Sat May 16 2020
...TROPICAL DEPRESSION FORMS OFF THE COAST OF EAST-CENTRAL
FLORIDA...
...TROPICAL STORM WATCH ISSUED FOR A PORTION OF THE NORTH CAROLINA
COAST...
SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...28.4N 78.6W
ABOUT 125 MI...200 KM E OF MELBOURNE FLORIDA
ABOUT 505 MI...810 KM SSW OF CAPE HATTERAS NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NNE OR 20 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
A Tropical Storm Watch has been issued for the North Carolina coast
from north of Surf City to Duck, including Pamlico and
Albemarle Sounds.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Watch is in effect for...
* New River Inlet to Duck NC
* Pamlico and Albemarle Sounds
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.
For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.
DISCUSSION AND OUTLOOK
----------------------
At 500 PM EDT (2100 UTC), the center of Tropical Depression One
was located near latitude 28.4 North, longitude 78.6 West. The
depression is moving toward the north-northeast near 13 mph (20
km/h) and this motion should continue during the next day or so.
After that time, a faster northeastward motion is expected. On
the forecast track, the depression is expected to move offshore,
but parallel to, the coast of Florida tonight, and then move near
or east of the coast of North Carolina on Monday.
Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Gradual strengthening is forecast, and the depression is expected
to become a tropical storm on Sunday.
The estimated minimum central pressure based on surface observations
and earlier aircraft reconnaissance data is 1008 mb (29.77 inches).
HAZARDS AFFECTING LAND
----------------------
WIND: Tropical storm conditions are possible within the watch
area by on Monday.
RAINFALL: The depression is expected to produce additional rain
accumulations of 1 to 2 inches over the central and northwest
Bahamas, and generally less than 1 inch over south Florida through
tonight. The depression is also expected to produce total rain
accumulations of 1 to 2 inches over coastal North Carolina Sunday
night and Monday.
SURF: Swells generated by the depression are affecting portions of
the east coast of central and northern Florida. These swells are
expected to spread northward during the next few days, and could
cause life-threatening surf and rip current conditions across much
of the U.S. southeast and mid-Atlantic coasts. Please consult
products from your local weather office.
NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM EDT.
Next complete advisory at 1100 PM EDT.
$$
Forecaster Cangialosi
Tropical Depression One Discussion Number 1
NWS National Hurricane Center Miami FL AL012020
500 PM EDT Sat May 16 2020
Satellite images, Doppler radar data, and surface observations
indicate that the low pressure system located just east of the coast
of central Florida has developed sufficient organization to now be
classified as a tropical depression. The low-level center is well
defined and deep convection has persisted near the center and in
bands on the east side of the circulation for the past several
hours. The cyclone is considered tropical instead of subtropical
because it has central deep convection and a relatively small radius
of maximum wind. The initial intensity is estimated to be 30 kt
based on data collected earlier today by the Air Force Hurricane
Hunters. Another aircraft is scheduled to investigate the system
this evening.
Based on satellite data and the earlier reconnaissance fixes, the
initial motion of the system is north-northeastward at 11 kt. A
continued north-northeastward motion at about the same forward speed
is expected during the next 24 hours or so, keeping the cyclone
offshore, but parallel to, the east coast of Florida. After that
time,
the model solutions begin to diverge and the details of the track
forecast become more complicated. The important features for the
future track of the depression appear to be a pair of mid- to
upper-level troughs currently over the central U.S. The specific
amplitude, timing, and location of those troughs will ultimately
result in how close to the coast of North Carolina this system gets.
The GFS and HWRF models are on the left side of the guidance and
bring the system inland or along the coast, while the ECMWF and
UKMET models show an offshore track. The NHC track forecast splits
the difference of these solutions, and lies close to the various
consensus models, which usually perform best. It should be noted
that forecast uncertainty is typically larger for weak systems like
this one.
The system should gradually strengthen during the next couple of
days as it remains over the Gulf Stream current and in relatively
low wind shear conditions. However, the surrounding air mass is not
particularly moist, so that and the marginally warm SSTs should
limit significant intensification. The NHC intensity forecast calls
for the system to become a tropical storm tonight or on Sunday with
continued slow strengthening as it nears the North Carolina coast.
Extratropical transition should occur in about 3 days, or sooner.
The NHC intensity forecast generally lies roughly near the middle of
the guidance envelope.
Key Messages:
1. A tropical storm watch has been issued for a portion of the
North Carolina coast. Tropical-storm-force winds and heavy rains
are possible there on Monday.
2. Dangerous coastal surf conditions and rip currents are expected
to spread northward from Florida to the mid-Atlantic states during
the next few days. See products from your local National Weather
Service for more details.
FORECAST POSITIONS AND MAX WINDS
INIT 16/2100Z 28.4N 78.6W 30 KT 35 MPH
12H 17/0600Z 29.7N 78.0W 35 KT 40 MPH
24H 17/1800Z 31.4N 77.4W 35 KT 40 MPH
36H 18/0600Z 33.0N 76.6W 40 KT 45 MPH
48H 18/1800Z 35.2N 74.8W 45 KT 50 MPH
60H 19/0600Z 37.1N 72.3W 50 KT 60 MPH
72H 19/1800Z 38.0N 70.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
96H 20/1800Z 38.0N 68.5W 45 KT 50 MPH...POST-TROP/EXTRATROP
120H 21/1800Z...DISSIPATED
$$
Forecaster Cangialosi
