000
WTNT42 KNHC 051443
TCDAT2

Tropical Depression Two Discussion Number   1
NWS National Hurricane Center Miami FL       AL022018
1100 AM AST Thu Jul 05 2018

For the past day or so, we've been monitoring a small area of low
pressure associated with a tropical wave over the tropical Atlantic
Ocean.  Despite a noticeable mid-level rotation in the convective
clouds, it had not been conclusive whether or not the system had a
closed circulation at the surface with a well-defined center.
However, the system appears more distinct and independent from the
Intertropical Convergence Zone as compared to yesterday, and
scatterometer data appears conclusive enough to support a closed,
yet tiny circulation.  We are now confident enough that the system
meets the criteria of a tropical cyclone, and have initiated
advisories on Tropical Depression Two with maximum winds of 30 kt,
which is supported by Dvorak classifications from TAFB and SAB.

The depression will be located in a relatively low-shear environment
for the next 3 days or so.  However, the small cyclone is surrounded
by abundant dry air, and the system will be moving over marginally
warm waters during the next few days, which could both limit
intensification.  The NHC official forecast allows for some slight
strengthening and most closely follows the HFIP Corrected Consensus
guidance (HCCA), showing the depression becoming a tropical storm
within the next 24 hours.  Between 72 and 96 hours, the system is
expected to begin encountering strong westerly shear and also
accelerate, both of which should cause it to degenerate into an open
wave east of the Lesser Antilles.

Even though the center has been difficult to locate, the initial
motion is estimated to be westward, or 270/14 kt.  The depression is
located to the south of a sprawling subtropical ridge, although a
break in the ridge over the central Atlantic may cause the system to
slow down a bit during the next 36 hours.  After that time, the
cyclone is likely to speed up again when it becomes situated to the
south of a new mid-level high.  The track guidance is in generally
good agreement, and the NHC official forecast is close to the TVCX
multi-model consensus and the HCCA guidance.

Even though the cyclone is expected to dissipate east of the Lesser
Antilles early next week, the remnant tropical wave will continue
moving quickly westward, likely bringing locally heavy rains and
gusty winds to portions of the Leeward Islands on Sunday and Monday.

FORECAST POSITIONS AND MAX WINDS

INIT  05/1500Z 10.2N  41.4W   30 KT  35 MPH
 12H  06/0000Z 10.7N  43.1W   30 KT  35 MPH
 24H  06/1200Z 11.4N  45.2W   35 KT  40 MPH
 36H  07/0000Z 12.1N  47.2W   35 KT  40 MPH
 48H  07/1200Z 12.9N  49.6W   35 KT  40 MPH
 72H  08/1200Z 14.7N  56.6W   35 KT  40 MPH
 96H  09/1200Z...DISSIPATED

$$
Forecaster Berg