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Hurricane Linda Discussion Number  10
NWS National Hurricane Center Miami FL       EP122021
900 AM MDT Thu Aug 12 2021
 
Linda has been trying to form an eye in conventional satellite 
imagery during the past few hours, but that feature has been 
obscured by the development of new convective bursts near the 
center.  An AMSR2 microwave pass from 0850 UTC indicated that the 
structure remains well organized, if not a little tilted with 
height due to shear, and a ragged mid-level eye feature was noted.  
Objective intensity estimates are at hurricane strength--T4.4/75 kt 
from the UW-CIMSS ADT and 66 kt from SATCON--but subjective CI 
numbers from TAFB and SAB remain at 3.5/55 kt.  Given the continued 
attempts at eye formation, I have elected to lean on the side of the 
objective numbers and increase the initial intensity to 65 kt, 
making Linda a hurricane.
 
The AMSR2 pass revealed that Linda has been moving a little to the
right of the previous forecast track, and the initial motion is
estimated to be west-northwestward, or 300/7 kt.  Mid-tropospheric
ridging located over northern Mexico should keep Linda on a
west-northwestward track for the next 2 to 3 days.  After that
time, another ridge is forecast to slide westward from California
out over the Pacific, which should have a blocking influence on
Linda and cause it to turn back toward the west.  In fact, by day 5,
most of the track models are showing a south-of-due-west motion.
On the whole, the guidance is showing a normal amount of spread, and 
the NHC track forecast has only been shifted slightly eastward and 
northward through day 3 to account for the adjustment of the initial 
position.  This solution is very close to the HCCA and TVCE 
consensus aids.

Moderate northerly to north-northeasterly shear continues to affect 
the cyclone, and the effect of this shear was seen in the slight 
offset of the low- and mid-level centers in microwave imagery.  The 
shear is forecast to subside slightly during the next couple of 
days while the hurricane moves over warm waters of 28-29 degrees 
Celsius and within an environment of upper-level divergence.  The 
limiting effects of the shear are likely to support gradual 
strengthening during the next couple of days, and the NHC intensity 
forecast is within the relatively tightly packed guidance suite 
during that time.  During the 3-5 day period, shear is expected to 
decrease substantially, but less conducive thermodynamic conditions 
should cause Linda to gradually lose intensity, potentially 
weakening to a tropical storm by day 5.

FORECAST POSITIONS AND MAX WINDS
 
INIT  12/1500Z 14.8N 107.7W   65 KT  75 MPH
 12H  13/0000Z 15.6N 109.1W   65 KT  75 MPH
 24H  13/1200Z 16.6N 111.2W   70 KT  80 MPH
 36H  14/0000Z 17.7N 113.4W   75 KT  85 MPH
 48H  14/1200Z 18.6N 115.5W   80 KT  90 MPH
 60H  15/0000Z 19.2N 117.6W   80 KT  90 MPH
 72H  15/1200Z 19.4N 119.6W   75 KT  85 MPH
 96H  16/1200Z 19.1N 123.4W   65 KT  75 MPH
120H  17/1200Z 19.0N 127.2W   55 KT  65 MPH
 
$$
Forecaster Berg
 
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