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Tropical Storm Otis Discussion Number 3
NWS National Hurricane Center Miami FL EP182023
1000 PM CDT Sun Oct 22 2023
Convection has been pulsing in the northwestern quadrant of Otis
during the past several hours, with less overall convective
activity than this afternoon. Microwave data and ship reports
suggests the center is southeast of the main area of deep
convection. The initial wind speed is kept at 35 kt, in line with
recent Dvorak T-number estimates.
Otis appears to be moving north-northwest at about 4 kt. The
biggest change to report on this advisory is that there's been a
notable northwest shift in the NHC track forecast. The synoptic
pattern of a trough over northwestern Mexico and a ridge over the
northwestern Caribbean would seem to favor a slow north-northwest
track for the next few days. Much of the GFS-based guidance,
however, appears to be too intertwined with the Intertropical
Convergence Zone, resulting in many of the aids not showing enough
motion during the next few days or even a track southward.
This doesn't seem realistic, and I've adjusted the forecast a large
distance to the northwest, with further northwest track changes
possible on later forecasts.
The storm will likely be in an environment of light-to-moderate
shear, with fairly high mid-level humidity over very warm water.
These conditions should promote gradual strengthening, which is
shown to begin after 12 hours to give the system some time to
re-align vertically. An increase in shear and possible land
interaction is forecast to cause Otis to level off in intensity
around midweek. This NHC intensity prediction is near the higher
end of the guidance, closer to the statistical guidance than the
dynamical models, the latter of which seem to be too low given the
large-scale environment.
FORECAST POSITIONS AND MAX WINDS
INIT 23/0300Z 11.1N 97.3W 35 KT 40 MPH
12H 23/1200Z 11.7N 97.4W 35 KT 40 MPH
24H 24/0000Z 12.6N 97.6W 40 KT 45 MPH
36H 24/1200Z 13.6N 97.9W 45 KT 50 MPH
48H 25/0000Z 14.5N 98.3W 50 KT 60 MPH
60H 25/1200Z 15.2N 98.7W 50 KT 60 MPH
72H 26/0000Z 16.1N 99.3W 50 KT 60 MPH
96H 27/0000Z 17.6N 100.6W 35 KT 40 MPH...INLAND
120H 28/0000Z...DISSIPATED
$$
Forecaster Blake
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