ZCZC MIATCDEP5 ALL
TTAA00 KNHC DDHHMM
 
Tropical Storm Lidia Discussion Number  17
NWS National Hurricane Center Miami FL       EP152023
300 AM MDT Sat Oct 07 2023

Scatterometer and microwave data indicate that Lidia remains a 
sheared tropical storm.  The center of the storm is on the eastern 
edge of an intense convective cloud shield, much as it has been 
for days now.  The initial intensity is reduced to 55 kt on this 
advisory, representing a compromise between coarse scatterometer 
data indicating 40-45 kt, and much higher satellite estimates.  

The center of Lidia has either moved or re-formed a bit to the 
south, and it seems to be moving westward at about 4 kt.  Lidia 
should slowly turn to the northwest and north during the next day 
or two while ridging weakens nearby.  After that time, a trough 
diving in from the eastern Pacific and northwestern Mexico should 
force the storm northeastward with increasing forward speed, in the 
general direction of west-central Mexico.  There is still a very 
large difference in the forward speeds of the guidance, with the 
GFS-based guidance much faster than the rest of the suite. Overall, 
most of the models are leaning toward a faster solution, and the 
next NHC track forecast is adjusted northeastward from the last 
one, though still well behind the GFS model.  

Persistent easterly shear is not forecast to abate during the next 
couple of days, thus little change in Lidia's intensity is 
anticipated during that time.  This shear could relax while the 
cyclone approaches Mexico, and gradual strengthening is shown then 
while Lidia moves over very warm waters, though some of the 
guidance increase the shear again before landfall.  There continues 
to be a large spread in the intensity models, from major hurricane 
strength to a tropical storm near landfall, resulting from the high 
track and environmental uncertainty.  The new forecast is reduced 
during the short term, consistent with the model trend, and is about 
the same as the last one at longer range.  This is considered a 
low-confidence prediction due to the reliance on the track forecast 
and the huge model spread.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  07/0900Z 16.0N 111.9W   55 KT  65 MPH
 12H  07/1800Z 16.1N 112.4W   55 KT  65 MPH
 24H  08/0600Z 16.6N 112.8W   55 KT  65 MPH
 36H  08/1800Z 17.3N 112.8W   55 KT  65 MPH
 48H  09/0600Z 17.9N 112.5W   55 KT  65 MPH
 60H  09/1800Z 18.5N 111.6W   60 KT  70 MPH
 72H  10/0600Z 19.2N 110.0W   65 KT  75 MPH
 96H  11/0600Z 21.0N 106.7W   60 KT  70 MPH
120H  12/0600Z 24.0N 102.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
$$
Forecaster Blake
 
NNNN