Tropical Depression Seven Forecast Discussion

491 
WTNT42 KNHC 130253
TCDAT2

Tropical Depression Seven Discussion Number   7
NWS National Hurricane Center Miami FL       AL072024
1100 PM AST Thu Sep 12 2024

The depression has been holding steady this evening.  After a lull 
in the convective activity which exposed the low-level circulation, 
thunderstorms have been building steadily to the east of the center. 
Unfortunately, the scatterometer pass missed the core of the system 
once again.  The initial intensity remains at 30 kt, close to the 
subjective Dvorak estimates from TAFB and SAB.

A subtropical ridge to the north of the depression is steering the 
system west-northwestward at about 14 kt.  As the ridge weakens 
during the next few days, the cyclone should gradually slow and turn 
more westward.  There is still a large spread in the track guidance 
envelope early next week, which seems partially related to the depth 
of the vortex.  The ECMWF solution shows a much stronger system that 
turns the cyclone to the north sooner compared to the GFS and 
GFS-based regional models showing a weaker system that moves faster 
and stays in the low-level westerly flow.  The latest NHC track 
forecast has been nudged a little to the south and lies between the 
previous prediction and the consensus aids. 

Marginal environmental conditions appear to be preventing the 
depression from making any appreciable intensity changes.  Visible 
satellite imagery from earlier today showed a band of Saharan dust 
wrapping around the northern semicircle of the circulation.  The 
intensity guidance has shifted downward again this cycle, with many 
models showing a steady-to-weakening system over the next 3-4 days.  
By the end of the forecast period, there is quite a bit of spread in 
the intensity guidance as noted earlier.  The latest NHC intensity 
forecast has been decreased slightly but remains on the high side of 
the various aids.


FORECAST POSITIONS AND MAX WINDS

INIT  13/0300Z 18.7N  37.0W   30 KT  35 MPH
 12H  13/1200Z 19.1N  38.5W   35 KT  40 MPH
 24H  14/0000Z 19.4N  40.7W   35 KT  40 MPH
 36H  14/1200Z 19.7N  42.4W   35 KT  40 MPH
 48H  15/0000Z 19.7N  44.0W   35 KT  40 MPH
 60H  15/1200Z 19.7N  45.6W   35 KT  40 MPH
 72H  16/0000Z 19.6N  47.2W   35 KT  40 MPH
 96H  17/0000Z 19.8N  49.1W   40 KT  45 MPH
120H  18/0000Z 20.5N  50.0W   45 KT  50 MPH

$$
Forecaster Bucci