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Tropical Storm Ivo Discussion Number 9
NWS National Hurricane Center Miami FL EP092025
200 PM MST Fri Aug 08 2025
Ivo's structure has become more organized during the past few
hours, with inner core banding becoming more pronounced. Recent
WSF-M and GMI microwave data were helpful in confirming the
improved structure, and also showed that Ivo's center was located a
little farther south than previously estimated. Despite the
improved structure, there is a wide range in intensity estimates.
Subjective Dvorak estimates from TAFB and SAB range from 55-65 kt,
while objective numbers from UW-CIMSS are stuck at 40-45 kt. To
add to the quandary, ASCAT data only showed maximum winds of 35 kt,
but it is highly likely that Ivo is too small for the instrument to
effectively sample its maximum winds. For now, Ivo's maximum winds
are set to 55 kt.
The storm has turned westward and continues to slow down with an
initial motion of 275/11 kt. A westward to west-northwestward
trajectory is forecast to continue for the next several days as
strong mid-level ridging remains entrenched to the north. The NHC
track forecast has been shifted south of the previous prediction to
account for the adjustment of the initial position, but otherwise
it is very close to the various multi-model consensus aids.
Some additional strengthening is anticipated during the next 12-24
hours while Ivo remains in an unstable environment with upper-level
divergence, and over waters warmer than 26 degrees Celsius.
While not explicitly shown in the forecast, Ivo could still
become a hurricane between the nominal forecast times. All of
the aforementioned environmental factors turn detrimental in about
36 hours, at which point more significant weakening is expected to
begin. Ivo could lose its deep convection and become post-tropical
in about 60 hours. Dissipation is now shown by day 4 in line with
the ECWMF, UKMET, and Canadian model solutions, with the GFS being
an outlier and continuing the remnant low westward for another day
or so after that.
FORECAST POSITIONS AND MAX WINDS
INIT 08/2100Z 20.4N 111.2W 55 KT 65 MPH
12H 09/0600Z 20.5N 112.5W 60 KT 70 MPH
24H 09/1800Z 20.7N 114.0W 60 KT 70 MPH
36H 10/0600Z 21.0N 115.7W 55 KT 65 MPH
48H 10/1800Z 21.5N 117.5W 45 KT 50 MPH
60H 11/0600Z 21.8N 119.4W 35 KT 40 MPH...POST-TROPICAL
72H 11/1800Z 21.9N 121.5W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 12/1800Z...DISSIPATED
$$
Forecaster Berg
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