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Hurricane Linda Discussion Number  27
NWS National Hurricane Center Miami FL       EP122021
1100 AM HST Mon Aug 16 2021

Linda still has a very striking appearance on visible satellite 
imagery, with a well-defined large eye, and multiple eyewall 
mesovorticies rotating about the mean center. However, the ring of 
cold cloud tops associated with the eyewall has become just a touch 
more ragged over the last few hours, and an earlier SSMIS microwave 
pass at 1518 UTC showed a break in the singular eyewall on the south 
side. The 1800 UTC Dvorak CI numbers were steady from SAB and TAFB, 
but the data-T numbers have decreased a bit from earlier today. In 
addition, the latest UW-CIMSS ADT intensity estimate was down to 
T4.8/85-kt. Therefore, Linda is estimated to be a bit weaker this 
advisory, with maximum sustained winds near 85-kt.
 
The initial motion is beginning to turn a bit more westward, now at 
260/8 kt. A well-established mid-level ridge north of Linda is 
expected to build in gradually to the northeast, allowing the storm 
to begin gaining latitude starting tomorrow. This west-northwest 
track is then expected to continue through the forecast period. The 
latest NHC track forecast is very close to the previous one, and is 
closest to the GEFX consensus, which is a simple blend of the most 
recent GFS and ECMWF forecasts. 
 
As discussed in previous advisories, Linda is expected to remain in 
a low deep-layer vertical-wind-shear environment (below 10 kt) for 
the next 4-5 days. Thus, Linda's intensity forecast is expected to 
be driven by a combination of thermodynamic factors and the 
cyclone's stable annular inner-core structure. While sea-surface 
temperatures (SSTs) are only between 25-26 C under the hurricane 
right now, the forecast track takes Linda back over slightly warmer 
SSTs in the 12-36 h period, and this could delay weakening in the 
short-term. The NHC intensity forecast continues to be above much of 
the intensity guidance, showing little change in intensity over the 
next 24-36 hours. In fact, when Linda moves over slightly warmer 
SSTs tomorrow, it would not be surprising to see a bit of 
restrengthening, assuming nearby dry-air does not disrupt the stable 
eyewall structure. However by 48 hours, SSTs decrease below 26 C in 
earnest and Linda is expected to begin a pronounced weakening trend. 
Towards the end of the forecast, Linda should become devoid of deep 
convection as indicated by the latest GFS and ECMWF IR brightness 
temperature forecast, and Linda is expected to become a 
post-tropical gale by Friday.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  16/2100Z 17.7N 124.6W   85 KT 100 MPH
 12H  17/0600Z 17.6N 125.9W   85 KT 100 MPH
 24H  17/1800Z 17.7N 127.7W   85 KT 100 MPH
 36H  18/0600Z 18.2N 129.8W   85 KT 100 MPH
 48H  18/1800Z 19.0N 132.2W   75 KT  85 MPH
 60H  19/0600Z 19.9N 134.8W   60 KT  70 MPH
 72H  19/1800Z 20.7N 137.5W   50 KT  60 MPH
 96H  20/1800Z 22.0N 142.6W   40 KT  45 MPH...POST-TROPICAL
120H  21/1800Z 23.0N 146.8W   35 KT  40 MPH...POST-TROPICAL
 
$$
Forecaster Papin/Brown
 
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