000
WTNT44 KNHC 230838
TCDAT4

Tropical Depression Chantal Discussion Number  10
NWS National Hurricane Center Miami FL       AL042019
500 AM AST Fri Aug 23 2019

Chantal's convection has become quite meager, with small
intermittent bursts continuing mainly to the east of the center.
Given the decreasing convective organization, Dvorak Current
Intensity numbers from TAFB and SAB are down to 1.5, and the initial
intensity is therefore lowered to 25 kt.  Large-scale subsidence
and a very dry air mass are making it harder and harder for Chantal
to maintain organized deep convection, and it's likely that the
depression will degenerate into a remnant low within the next 24
hours.  Each of the global models shows the remnant low hanging
around for various periods of time, but the official forecast
continues to show dissipation in 72 hours, which is in closest
agreement with the ECMWF model.

Chantal is moving southeastward, or 140/7 kt.  High pressure in the
lower levels of the atmosphere is expected to jump from the
southwest to the northeast of Chantal during the next couple of
days, which will cause the depression/remnant low to move slowly
southward and then westward before dissipating.  The latest track
guidance (and thus the official forecast) shows a more sweeping
curved trajectory than before, but in the grand scheme of things
the change is not that significant.  The new NHC forecast generally
lies between the TVCX and HCCA consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT  23/0900Z 37.1N  40.9W   25 KT  30 MPH
 12H  23/1800Z 36.3N  40.7W   25 KT  30 MPH
 24H  24/0600Z 35.4N  41.4W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  24/1800Z 35.2N  42.7W   20 KT  25 MPH...POST-TROP/REMNT LOW
 48H  25/0600Z 35.4N  43.8W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  26/0600Z...DISSIPATED

$$
Forecaster Berg