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Hurricane Linda Discussion Number  23
NWS National Hurricane Center Miami FL       EP122021
1100 AM HST Sun Aug 15 2021
 
Linda now has the classic truck tire or doughnut appearance of an 
annular hurricane in infrared satellite imagery.  The large eye is 
about 35 n mi in diameter, and the surrounding cold cloud tops are 
uniformly 70-90 n mi thick in all quadrants.  The initial intensity 
is lowered slightly to 95 kt based on Dvorak estimates of T5.0/90 kt 
from TAFB and T5.5/102 kt from SAB, and this value also matches the 
latest objective ADT and SATCON estimates.

Linda has almost turned toward the west-southwest with an initial 
motion of 260/10 kt, a result of a strong mid-level high centered 
over California and Nevada.  This feature should push Linda toward 
the west-southwest during the next 24 hours, but a repositioning of 
the high over the North Pacific in a few days will allow the 
hurricane to turn back toward the west by 36 hours and then the 
west-northwest by day 3.  The track models remain in good agreement 
on this scenario.  The NHC track forecast lies near the southern 
edge of the guidance envelope, leaning towards the HCCA consensus 
aid, and it essentially lies right on top of the previous official 
forecast.

With little to no shear expected during the next 5 days, Linda's 
intensity will be driven by thermodynamic factors.  The hurricane's 
west-southwestward motion has it paralleling the sea surface 
temperature gradient, keeping it over waters around 26 degrees 
Celsius for the next 3 days or so.  Since annular hurricanes 
typically weaken only gradually with these types of environmental 
conditions, the NHC intensity forecast is above the various 
intensity consensus aids and leans toward the SHIPS model, which is 
at the upper end of the guidance envelope.  Linda is likely to 
weaken below hurricane intensity after day 3 once it moves over 
much colder waters.  Although not explicitly shown here, it is 
possible that Linda could lose organized deep convection and become 
a post-tropical gale by day 5.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  15/2100Z 18.8N 121.2W   95 KT 110 MPH
 12H  16/0600Z 18.4N 122.5W   90 KT 105 MPH
 24H  16/1800Z 17.8N 124.3W   85 KT 100 MPH
 36H  17/0600Z 17.6N 126.0W   80 KT  90 MPH
 48H  17/1800Z 17.7N 127.7W   75 KT  85 MPH
 60H  18/0600Z 18.1N 129.7W   70 KT  80 MPH
 72H  18/1800Z 18.9N 132.0W   65 KT  75 MPH
 96H  19/1800Z 20.7N 136.7W   55 KT  65 MPH
120H  20/1800Z 22.5N 140.9W   40 KT  45 MPH
 
$$
Forecaster Berg
 
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