TROPICAL DEPRESSION TWELVE-E DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL EP122016
300 PM MDT THU AUG 18 2016
Satellite imagery indicates that the deep convection associated
with the low pressure system located 350 miles south of the
southern tip of the Baja Peninsula has become sufficiently well
organized to classify this system as a tropical depression.
Therefore, advisories are being initiated at this time. The
depression should remain in a marginally conducive thermodynamic
environment with relatively low vertical shear and over warm oceanic
waters for the next 36-48 hours. Therefore, modest strengthening is
forecast. Through the remainder of the period, the cyclone should
be moving into a more stable and drier air mass. Subsequently, a
gradual weakening trend is expected to begin in about 48 hours and
the cyclone should degenerate into a remnant low in 3 days or so.
The official intensity forecast is based on the IVCN and sides with
the trend implied by the GFS global and ensemble mean, the HWRF and
the COAMPS-TC which all show the system dissipating in 5 days, or
less.
The initial motion is estimated to be 315/6 kt, within the
southeasterly mid-level flow on the periphery of a subtropical ridge
originating over northern Mexico. The depression should continue on
a northwestward to north-northwestward motion through the 48 hour
period. After that time, the cyclone is forecast to gradually turn
northward in response to a growing weakness in the ridge to the
north, and then turn slowly back toward the northwest in response to
the low-level tradewind flow as a shallow, remnant low. It's worth
noting that the GFS shows the cyclone weakening much more quickly
than the ECMWF, and meandering south of the southern tip the Baja
California peninsula before dissipating over water. The NHC
forecast sides with the multi-model TVCN, and is nudged a bit toward
the left of it, near an average of the ECMWF and GFS global models.
FORECAST POSITIONS AND MAX WINDS
INIT 18/2100Z 17.8N 110.1W 30 KT 35 MPH
12H 19/0600Z 18.5N 110.7W 35 KT 40 MPH
24H 19/1800Z 19.4N 111.3W 35 KT 40 MPH
36H 20/0600Z 20.1N 111.6W 35 KT 40 MPH
48H 20/1800Z 20.6N 111.7W 30 KT 35 MPH
72H 21/1800Z 21.2N 111.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 22/1800Z 21.7N 112.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 23/1800Z 23.5N 114.4W 20 KT 25 MPH...POST-TROP/REMNT LOW
$$
Forecaster Roberts
NNNN
NWS NATIONAL HURRICANE CENTER MIAMI FL EP122016
300 PM MDT THU AUG 18 2016
Satellite imagery indicates that the deep convection associated
with the low pressure system located 350 miles south of the
southern tip of the Baja Peninsula has become sufficiently well
organized to classify this system as a tropical depression.
Therefore, advisories are being initiated at this time. The
depression should remain in a marginally conducive thermodynamic
environment with relatively low vertical shear and over warm oceanic
waters for the next 36-48 hours. Therefore, modest strengthening is
forecast. Through the remainder of the period, the cyclone should
be moving into a more stable and drier air mass. Subsequently, a
gradual weakening trend is expected to begin in about 48 hours and
the cyclone should degenerate into a remnant low in 3 days or so.
The official intensity forecast is based on the IVCN and sides with
the trend implied by the GFS global and ensemble mean, the HWRF and
the COAMPS-TC which all show the system dissipating in 5 days, or
less.
The initial motion is estimated to be 315/6 kt, within the
southeasterly mid-level flow on the periphery of a subtropical ridge
originating over northern Mexico. The depression should continue on
a northwestward to north-northwestward motion through the 48 hour
period. After that time, the cyclone is forecast to gradually turn
northward in response to a growing weakness in the ridge to the
north, and then turn slowly back toward the northwest in response to
the low-level tradewind flow as a shallow, remnant low. It's worth
noting that the GFS shows the cyclone weakening much more quickly
than the ECMWF, and meandering south of the southern tip the Baja
California peninsula before dissipating over water. The NHC
forecast sides with the multi-model TVCN, and is nudged a bit toward
the left of it, near an average of the ECMWF and GFS global models.
FORECAST POSITIONS AND MAX WINDS
INIT 18/2100Z 17.8N 110.1W 30 KT 35 MPH
12H 19/0600Z 18.5N 110.7W 35 KT 40 MPH
24H 19/1800Z 19.4N 111.3W 35 KT 40 MPH
36H 20/0600Z 20.1N 111.6W 35 KT 40 MPH
48H 20/1800Z 20.6N 111.7W 30 KT 35 MPH
72H 21/1800Z 21.2N 111.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 22/1800Z 21.7N 112.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 23/1800Z 23.5N 114.4W 20 KT 25 MPH...POST-TROP/REMNT LOW
$$
Forecaster Roberts
NNNN
