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Tropical Storm Lidia Discussion Number  15
NWS National Hurricane Center Miami FL       EP152023
300 PM MDT Fri Oct 06 2023

Lidia remains sheared, with its low-level center nearly exposed in 
recent visible satellite imagery. Confidence in the center position 
of Lidia is therefore much higher than it was six hours ago. Recent 
Dvorak intensity fixes still appear to be inflated relative to 
Lidia's observed structure. Thus, the intensity estimate is again 
based heavily on objective techniques that incorporate microwave 
data, such as the UW-CIMSS DMINT, which still support an intensity 
near 60 kt.

For the next 2-3 days, confidence in the NHC track and intensity 
forecasts is fairly high. Lidia is forecast to continue moving 
generally westward to west-northwestward today, and then gradually 
turn northward through the weekend. The tropical storm will likely
remain sheared during this time, which should result in only small 
fluctuations in intensity. Lidia could still become a hurricane 
tonight or over the weekend. 

Beyond about 72 h, the forecast uncertainty increases substantially. 
The tropical storm is forecast to interact with a mid-latitude 
short-wave trough, which should cause it to accelerate 
northeastward. The trough interaction will also cause a change in 
the environmental mid- to upper-level wind pattern, resulting in a 
southwesterly shear vector and an increase in upper-level difluence. 
Some models, including both HAFS-A and HAFS-B, indicate that Lidia 
could begin to strengthen at this time, while others keep it 
steady-state and strongly sheared. There is also uncertainty with 
the forward speed of Lidia. For instance, the GFS shows a much 
faster forward speed than most other models. Run-to-run consistency 
of the models in the 4-5 day time frame has been poor today, so only 
very small adjustments were made to the NHC forecast at this time. 
Larger changes may be required over the weekend as the forecast 
becomes clearer.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  06/2100Z 16.4N 111.2W   60 KT  70 MPH
 12H  07/0600Z 16.4N 112.0W   65 KT  75 MPH
 24H  07/1800Z 16.6N 112.8W   65 KT  75 MPH
 36H  08/0600Z 17.0N 113.4W   65 KT  75 MPH
 48H  08/1800Z 17.6N 113.6W   60 KT  70 MPH
 60H  09/0600Z 18.2N 113.4W   60 KT  70 MPH
 72H  09/1800Z 18.7N 112.7W   60 KT  70 MPH
 96H  10/1800Z 19.8N 109.8W   60 KT  70 MPH
120H  11/1800Z 21.5N 107.5W   55 KT  65 MPH
 
$$
Forecaster D. Zelinsky/Delgado
 
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