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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
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