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Tropical Depression Fourteen-E Discussion Number 1
NWS National Hurricane Center Miami FL EP142018
800 PM PDT Tue Aug 14 2018
The area of disturbed weather and associated low pressure area that
the NHC has been tracking for the past few days has acquired enough
organized deep convection for the system to be declared a tropical
depression. Although the convection had waned a little during the
day, recent satellite imagery indicates that convection near the
well-defined center has begun to increase and that outer banding
features in the western semicircle have been improving during the
past few hours. The initial intensity of 30 kt is based on a Dvorak
satellite intensity estimate of T2.0/30 kt from TAFB.
The initial motion estimate is 265/12 kt. For the next 72 hours, the
tropical cyclone is forecast to move westward or slightly south of
due west along the southern periphery of a broad deep-layer ridge
that is located to the north of the depression. The ridge is
expected to weaken by 96 hours as a mid-latitude low/trough
currently located off the coast of southern California digs
southward and then westward during the forecast period. This
pattern should allow the cyclone to move west-northward into the
weakness in the ridge and start gaining latitude. For this initial
forecast of the system, the NHC track lies close to a blend of the
consensus track models HCCA and TVCE.
The vertical wind shear is forecast to remain around 10 kt or less
for the next 72 hours or so, with a further decrease on days 4 and 5
when the system moves underneath and/or develops an upper-level
anticyclone, conditions that typically favor significant
intensification. However, since the circulation envelope is
currently elongated northeast-to-southwest, it will take a couple of
days for the system to become more symmetrical, which could then
enhance the strengthening process. By that time, however, sea-
surface temperatures and mid-level humidity values will be marginal
for significant intensification to occur. As a result, only slow but
steady strengthening is indicated in this first intensity forecast,
which closely follows the HCCA intensity consensus model.
FORECAST POSITIONS AND MAX WINDS
INIT 15/0300Z 10.9N 121.2W 30 KT 35 MPH
12H 15/1200Z 10.8N 122.9W 35 KT 40 MPH
24H 16/0000Z 10.7N 125.2W 40 KT 45 MPH
36H 16/1200Z 10.8N 127.3W 45 KT 50 MPH
48H 17/0000Z 11.0N 129.5W 50 KT 60 MPH
72H 18/0000Z 12.0N 134.1W 65 KT 75 MPH
96H 19/0000Z 13.8N 138.6W 80 KT 90 MPH
120H 20/0000Z 15.6N 142.8W 90 KT 105 MPH
$$
Forecaster Stewart
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