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Tropical Depression Jova Discussion Number 4
NWS National Hurricane Center Miami FL EP122017
300 PM MDT Sat Aug 12 2017
The convective structure of Jova is practically non-existent. Deep
convection is limited to a small burst southwest of the center.
A pair of ASCAT passes at 1638 UTC and 1732 UTC showed maximum
winds of around 30 kt. Based on these data, the initial intensity
has been lowered to 30 kt, making Jova a tropical depression.
Even though the vertical wind shear is still very high, the rapid
decline of convection is a little surprising to me since the SSTs
beneath the circulation are above 28 deg C, and the tropical cyclone
is embedded within an environment of high total precipitable water
and moderate mid-level moisture. Given those environmental factors,
the NHC forecast assumes that Jova will regain at least a little
convection and maintain tropical cyclone status for another 24 h.
However, if current trends continue, the depression could become a
remnant low sooner than indicated. After about 24 h, the cyclone
should gradually spin down while moving over cooler SSTs and into a
drier environment.
Since the center of circulation is completely exposed, the motion
is now a far more certain 280/12 kt. No significant changes have
been made to the NHC track forecast, and the depression, or its
remnants, should continue moving steadily westward, steered by a
mid-level ridge to the north until eventual dissipation in 3 or 4
days.
FORECAST POSITIONS AND MAX WINDS
INIT 12/2100Z 20.4N 113.1W 30 KT 35 MPH
12H 13/0600Z 20.7N 115.2W 30 KT 35 MPH
24H 13/1800Z 20.8N 117.8W 30 KT 35 MPH
36H 14/0600Z 20.9N 120.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 14/1800Z 20.9N 122.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 15/1800Z 20.4N 127.3W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 16/1800Z...DISSIPATED
$$
Forecaster Zelinsky
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