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Tropical Storm Hector Discussion Number 12
NWS National Hurricane Center Miami FL EP082024
500 AM HST Wed Aug 28 2024
GOES-18 proxy-vis imagery shows that the low-level center of Hector
is exposed to the southwest of a large area of deep convection. A
28/1040 UTC ATMS microwave pass also supports the analysis of the
exposed center located to the southwest of the convection. An
ASCAT-B pass from 28/0608 UTC showed wind vectors up to 38 kt to the
north of the center. However, the ASCAT data also shows that the
wind structure on the south side is becoming weak and elongated.
Although the scatterometer data still shows some weak west winds on
the south side, Hector could be close to opening up into a trough.
Subjective current intensity estimates are 45 kt from both TAFB and
SAB. Objective intensity estimates from UW-CIMSS are a bit lower,
ranging from 35 to 44 kt. The initial intensity is held at 45 kt
for this advisory.
The center of Hector is becoming a bit more ambiguous as there
appears to be a couple of weak swirls, and the best estimate of the
motion is westward, or 275/9 kt. The cyclone should continue moving
close to due west, steered by a low- to mid-level subtropical ridge
to its north. The new NHC forecast is just a tad slower than the
previous official forecast and is close to the TVCE consensus aid.
Moderate west-southwesterly wind shear has already caused the
convective area to be displaced well to the northeast of the
center. Given that Hector is expected to continue traveling within
an environment of marginal SSTs, dry air, and moderate
southwesterly shear, the NHC forecast will continue to show
weakening, in agreement with the latest intensity consensus
guidance. Simulated satellite imagery from the GFS and ECMWF
models suggests that Hector should lose its convection on Thursday,
and the official forecast continues to show Hector degenerating to
a remnant low at that time. Most of the global models show the
remnants of Hector opening up into a trough by Friday. However,
given the recent deteriorating surface wind structure observed on
ASCAT and GOES-18 proxy vis imagery, it would not be surprising if
Hector dissipated sooner than forecast.
FORECAST POSITIONS AND MAX WINDS
INIT 28/1500Z 18.3N 132.9W 45 KT 50 MPH
12H 29/0000Z 18.4N 134.5W 40 KT 45 MPH
24H 29/1200Z 18.5N 136.8W 35 KT 40 MPH
36H 30/0000Z 18.5N 139.4W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 30/1200Z 18.4N 142.3W 30 KT 35 MPH...POST-TROP/REMNT LOW
60H 31/0000Z...DISSIPATED
$$
Forecaster Hagen/Reinhart/Konarik
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