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Tropical Depression THREE


Tropical Depression Three Discussion Number   1
NWS National Hurricane Center Miami FL       AL032018
500 PM EDT Fri Jul 06 2018

The area of low pressure located a few hundred miles southeast of
the North Carolina coast has developed enough deep convection
with a well-defined circulation to be classified as a tropical
depression.  This is supported by a Dvorak T-number of 2.0 from
TAFB, and an earlier ASCAT pass with 25-kt winds, which is the
initial intensity assigned to the depression.  Given that the system
is moving over warm waters and in a low-shear environment, gradual
strengthening is indicated, and the NHC forecast shows the
depression becoming a tropical storm on Saturday.  Additional
intensification could occur by the end of the forecast period when
the cyclone moves northeastward away from the U.S coast and
interacts with a mid-level trough. The intensity forecast is very
close to the SHIPS model and the Corrected Consensus HCCA.

The depression is moving toward the north-northwest or 335 degrees
at about 4 knots. The tropical cyclone is currently located on the
southwestern edge of the subtropical ridge, and this weak flow
pattern should keep the depression on the same slow track for the
next 24 hours or so.  After that time, the steering currents are
expected to collapse, and the cyclone should begin to meander for a
couple of days well off the coast of North Carolina.  Then a
mid-level trough is expected to approach from the west and force
the system on a northeastward track.

Most of the guidance suggests that the tropical-storm-force winds
associated with the cyclone will occur in the eastern quadrant
well away from the U.S. coast.  On this basis, no watches or
warnings are required for the U.S coast at this time, however,
interests along the North Carolina coast should monitor the
progress of this system.

Due to a technical issue, the wind speed probability values at land
locations in the wind speed probability text product are too high
and do not reflect reduced probabilities that are expected over
land.  The wind speed probability values provided in the graphics
on the NHC website at, and in the publicly
disseminated grid files do correctly reflect the reduced
probabilities over land.  As a result, users should refer to the NHC
website graphics and gridded products instead of the text product
for the most accurate wind speed probability values until this
problem is resolved.


INIT  06/2100Z 32.2N  73.8W   25 KT  30 MPH
 12H  07/0600Z 32.9N  74.3W   30 KT  35 MPH
 24H  07/1800Z 33.7N  74.5W   35 KT  40 MPH
 36H  08/0600Z 34.0N  74.3W   40 KT  45 MPH
 48H  08/1800Z 34.0N  74.0W   45 KT  50 MPH
 72H  09/1800Z 33.5N  73.7W   50 KT  60 MPH
 96H  10/1800Z 33.5N  73.7W   65 KT  75 MPH
120H  11/1800Z 36.5N  69.5W   70 KT  80 MPH

Forecaster Avila