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Tropical Depression Nineteen-E Discussion Number 2
NWS National Hurricane Center Miami FL EP192020
1000 PM CDT Mon Oct 05 2020
Tropical Depression Nineteen-E is beginning to show better signs of
organization tonight. Recent satellite imagery depicts a burst of
deep convection near the estimated center of the depression with
cloud top temperatures colder than -70 degrees Celsius. This trend,
along with recent UW-CIMSS ADT estimates, suggests the system may
be nearing tropical storm strength. The initial intensity is
perhaps conservatively held at 30 kt for this advisory based on
earlier T2.0 classifications from TAFB and SAB.
The estimated initial motion of the depression remains 340/6 kt.
This general motion should continue through the overnight hours as
the system is steered by a mid-level ridge over southern Mexico.
As the ridge weakens through the middle of the week, the steering
currents will break down and the system will likely meander well
offshore of the southwestern coast of Mexico for several days. By
days 4-5, global models indicate the ridge should rebuild over
southern Mexico, which would eventually support a northwestward
motion late in the forecast period. The NHC forecast track shows
little change with this advisory, and remains close to the HFIP
corrected consensus HCCA.
The intensity forecast remains challenging with above average spread
in the guidance. The environmental conditions generally appear
favorable, with low to moderate deep-layer wind shear and warm sea
surface temperatures. The statistical-dynamical SHIPS guidance
indicates gradual strengthening will occur over the next several
days. However, global models including the GFS and ECMWF, along with
the HWRF and HMON, forecast little intensity change or even
weakening as the system meanders well offshore. This could be a
product of the system struggling to separate from the Intertropical
Convergence Zone (ITCZ), or possible upwelling as it drifts over the
same general area for several days. Given these mixed signals in the
guidance, the NHC intensity forecast remains close to the previous
advisory and only shows modest strengthening during the forecast
period. This forecast still lies slightly above the IVCN and HCCA
consensus aids.
FORECAST POSITIONS AND MAX WINDS
INIT 06/0300Z 13.3N 105.6W 30 KT 35 MPH
12H 06/1200Z 13.8N 106.1W 35 KT 40 MPH
24H 07/0000Z 14.0N 106.6W 35 KT 40 MPH
36H 07/1200Z 13.8N 106.6W 35 KT 40 MPH
48H 08/0000Z 13.7N 106.5W 35 KT 40 MPH
60H 08/1200Z 13.9N 106.5W 35 KT 40 MPH
72H 09/0000Z 14.1N 106.6W 40 KT 45 MPH
96H 10/0000Z 14.5N 107.5W 40 KT 45 MPH
120H 11/0000Z 15.0N 108.5W 40 KT 45 MPH
$$
Forecaster Reinhart/Zelinsky
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