500 PM HST Tue Aug 27 2024
Deep convection associated with Gilma has continued to decrease,
with only a small cluster currently remaining in the southeastern
quadrant. The various subjective and objective satellite intensity
estimates thus continue to indicate rapid weakening, with the range
of intensities now from 35-55 kt. Based on these estimates, the
initial intensity is reduced to 45 kt in best agreement with the
CIMSS satellite consensus.
Gilma should cross a tongue of colder sea surface temperatures
during the next 12 h, and that, combined with increasing shear,
should continue the current weakening. After that time, while the
sea surface temperatures increase a little along the forecast track,
even stronger shear and dry air entrainment should keep Gilma
weakening. The new intensity forecast calls for the system to
degenerate to a remnant low by 48 h and to weaken to a trough
between 72-96 h.
The initial motion is now 270/11 kt. A ridge north of Gilma will
continue to steer the cyclone westward to west-northwestward until
it dissipates. There has been little change in the track guidance,
and the new forecast track is similar to the previous track.
FORECAST POSITIONS AND MAX WINDS
INIT 28/0300Z 18.5N 143.3W 45 KT 50 MPH
12H 28/1200Z 18.7N 145.0W 40 KT 45 MPH
24H 29/0000Z 19.1N 147.3W 35 KT 40 MPH
36H 29/1200Z 19.6N 149.4W 30 KT 35 MPH
48H 30/0000Z 20.1N 151.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
60H 30/1200Z 20.7N 154.0W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 31/0000Z 21.2N 156.4W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 01/0000Z...DISSIPATED
500 PM HST Tue Aug 27 2024
Hector this evening continues to produce a large area of deep
convection, though this activity is struggling to become better
organized and wrap around the circulation center, possibly due to
continued 15-20 kt westerly shear helping to entrain very dry
mid-level air near its center. Subjective and objective intensity
estimates remain largely unchanged this evening, and the initial
intensity will remain 45 kt for this advisory.
The tropical storm continues to move off to the west-northwest at
285/10 kt. The mid-level ridge currently steering Hector is expected
to weaken somewhat as a mid- to upper-level weakness forms north of
Hector. However, the cyclone is also likely to become more
vertically shallow and thus steered more by a low-level ridge that
will remain in place to the north. Thus, the track forecast shows
Hector bending back more westward over the next several days. The
latest NHC track forecast is very close to the previous advisory and
lies in the middle of the guidance envelope.
The overall environment near Hector currently is not all that
favorable for much additional strengthening. The current moderate
shear is not forecast to let up much as Hector also moves over the
cold wake left behind by Gilma, which itself has dramatically
weakened as it encountered less favorable conditions. Thus,
weakening continues to be forecast with Hector, in good agreement
with the intensity guidance. Both the GFS and ECMWF still show the
cyclone losing its remaining organized convection after 48 hours,
and the NHC forecast shows the system becoming a post-tropical
remnant low before it crosses into the Central Pacific basin.
FORECAST POSITIONS AND MAX WINDS
INIT 28/0300Z 18.2N 131.0W 45 KT 50 MPH
12H 28/1200Z 18.4N 132.6W 40 KT 45 MPH
24H 29/0000Z 18.6N 134.7W 35 KT 40 MPH
36H 29/1200Z 18.6N 137.0W 30 KT 35 MPH
48H 30/0000Z 18.5N 139.8W 30 KT 35 MPH...POST-TROP/REMNT LOW
60H 30/1200Z 18.4N 142.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 31/0000Z...DISSIPATED
500 PM HST Tue Aug 27 2024 Deep convection associated with Gilma has continued to decrease, with only a small cluster currently remaining in the southeastern quadrant. The various subjective and objective satellite intensity estimates thus continue to indicate rapid weakening, with the range of intensities now from 35-55 kt. Based on these estimates, the initial intensity is reduced to 45 kt in best agreement with the CIMSS satellite consensus. Gilma should cross a tongue of colder sea surface temperatures during the next 12 h, and that, combined with increasing shear, should continue the current weakening. After that time, while the sea surface temperatures increase a little along the forecast track, even stronger shear and dry air entrainment should keep Gilma weakening. The new intensity forecast calls for the system to degenerate to a remnant low by 48 h and to weaken to a trough between 72-96 h. The initial motion is now 270/11 kt. A ridge north of Gilma will continue to steer the cyclone westward to west-northwestward until it dissipates. There has been little change in the track guidance, and the new forecast track is similar to the previous track. FORECAST POSITIONS AND MAX WINDS INIT 28/0300Z 18.5N 143.3W 45 KT 50 MPH 12H 28/1200Z 18.7N 145.0W 40 KT 45 MPH 24H 29/0000Z 19.1N 147.3W 35 KT 40 MPH 36H 29/1200Z 19.6N 149.4W 30 KT 35 MPH 48H 30/0000Z 20.1N 151.7W 30 KT 35 MPH...POST-TROP/REMNT LOW 60H 30/1200Z 20.7N 154.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 31/0000Z 21.2N 156.4W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 01/0000Z...DISSIPATED
