ZCZC MIATCDEP3 ALL
TTAA00 KNHC DDHHMM
 
Hurricane Hilda Discussion Number   6
NWS National Hurricane Center Miami FL       EP082021
800 PM PDT Sat Jul 31 2021

Hilda has resumed strengthening during the past several hours, 
including the short-lived appearance of an eye in the central 
dense overcast.  Recent 37-GHz microwave imagery confirms an eye 
is developing, but indicates that the eyewall is not yet closed on 
the northeastern side of the eye.  Satellite intensity estimates 
from TAFB and SAB are 77 kt, while the CIMSS satellite consensus is 
near 80 kt.  Based on these data, the initial intensity is increased 
to a possibly conservative 75 kt.

Although Hilda is experiencing some easterly vertical shear, 
conditions are generally conducive for strengthening during the 
next 24 h, and the early part of the intensity forecast has been 
adjusted upward based mainly on current trends.  After that 
time, decreasing moisture and decreasing sea surface temperatures 
along the forecast track should cause steady weakening.  The latter 
part of the intensity forecast has only minor changes from the 
previous forecast and follows the trend of the intensity guidance.

The initial motion is now a little slower at 285/9.  The 
subtropical ridge to the north should steer Hilda generally 
west-northwestward for the next several days, with a more 
northwestward motion around 96 h as the cyclone passes south of a 
weakness in the ridge.  Overall, the guidance envelope has shifted a 
little northward since the previous advisory, and the new forecast 
track is also adjusted northward.  It should be noted, though, that 
the global models continue to show the possibility of erratic motion 
due to Hilda interacting with TD-9E to the west and the weaker, but 
larger, low pressure area to the east.  The most drastic example of 
this is in the Canadian model, which shows Hilda taking a 
significant turn to the south before resuming a northward motion.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  01/0300Z 14.3N 118.7W   75 KT  85 MPH
 12H  01/1200Z 14.7N 120.0W   85 KT 100 MPH
 24H  02/0000Z 15.2N 121.7W   90 KT 105 MPH
 36H  02/1200Z 15.8N 123.1W   85 KT 100 MPH
 48H  03/0000Z 16.4N 124.2W   80 KT  90 MPH
 60H  03/1200Z 17.2N 125.4W   75 KT  85 MPH
 72H  04/0000Z 18.3N 126.8W   65 KT  75 MPH
 96H  05/0000Z 20.0N 130.5W   50 KT  60 MPH
120H  06/0000Z 20.5N 134.0W   40 KT  45 MPH
 
$$
Forecaster Beven
 
NNNN