Tropical Storm Hector Forecast Discussion

654 
WTPZ43 KNHC 281433
TCDEP3

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