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Tropical Depression Eleven Forecast Discussion

WTNT41 KNHC 281436

Tropical Depression Eleven Discussion Number   1
NWS National Hurricane Center Miami FL       AL112022
1100 AM AST Wed Sep 28 2022

Over the past 24 hours, convection has been gradually increasing in 
organization with the well-defined area of low pressure located 
several hundred miles to the west of the Cabo Verde islands. 
Overnight, we received Metop-B and C scatterometer data that 
confirmed a closed cyclonic circulation, with peak winds up to at 
least 30 kt in the deeper convection to the east of the center 
location. There were even a few higher wind retrievals, but these 
may have been rain contaminated in the intense convection. Since 
that time, the convection has remained persistent, and TAFB has been 
providing a subjective intensity estimate of T2.0/30-kt for the last 
12-18 hours. A more recent scatterometer pass also indicates the 
circulation remains closed and well-defined. Thus, the system can be 
considered a tropical depression, and the maximum sustained winds 
will be set at 30-kt for this advisory. 

After meandering in the same location for the last 2-4 days, the 
depression now appears to be finally gaining some latitude with the 
estimated motion at 350/8-kt. The very slow motion over the past few 
days was related to a large weakness in the steering flow due to a 
broad and expansive upper-level trough to the north. Low to 
mid-level ridging is finally starting to nose in from the east over 
the past 24 hours, and the ongoing northward motion is expected to 
continue with a gradual turn more north-northwestward. The guidance 
is in fairly good agreement with this solution, and the initial NHC 
forecast track follows closely with the reliable consensus aids TVCN 
and HFIP corrected consensus approach (HCCA). 

The depression has a short window to intensify a bit more in the 
short-term, while the vertical wind shear remains under 10 kt for 
the next 12-18 hours. However, as the storm gains latitude, it will 
quickly become highly sheared from the aforementioned upper-level 
trough that lies along its track. Thus, only slight strengthening is 
shown in the 12-h forecast followed by a steady state or weakening 
tropical cyclone in the 24-48 hour forecast period. The system is 
expected to open up into a trough by 72 hours as it succumbs to the 
highly unfavorable environment, and this could occur sooner than 
forecasted. The NHC intensity forecast is in good agreement with the 
majority of the guidance, and also lies near the HCCA aid. 


INIT  28/1500Z 16.1N  34.4W   30 KT  35 MPH
 12H  29/0000Z 17.1N  35.0W   35 KT  40 MPH
 24H  29/1200Z 19.0N  36.3W   35 KT  40 MPH
 36H  30/0000Z 20.8N  38.1W   35 KT  40 MPH
 48H  30/1200Z 23.8N  39.3W   30 KT  35 MPH
 60H  01/0000Z 26.4N  39.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  01/1200Z...DISSIPATED

Forecaster Papin

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