000
WTPZ41 KNHC 160242
TCDEP1
 
Tropical Storm Karina Discussion Number  13
NWS National Hurricane Center Miami FL       EP162020
Issued by NWS Central Pacific Hurricane Center Honolulu HI
800 PM PDT Tue Sep 15 2020
 
Satellite imagery shows that Karina's outflow has improved over the 
past 6 hours, but persistent deep convection over the low-level 
center has shown some signs of warming/weakening in the last couple 
hours. The initial intensity for this advisory is maintained at 50 
kt, primarily based on a blend of subjective Dvorak intensity 
estimates of 45-55 kt from SAB/TAFB/HFO. 

Karina is moving toward the northwest at 10 kt (310/10 kt), steered 
by a mid- and upper-level ridge to the northeast and north, 
respectively. Although some relaxation of the recent northeasterly 
to easterly shear is expected to continue in the short-term, 
gradual weakening is expected as Karina is now over sub-26C water. 
As Karina rounds the southwestern portion of the deep-layer ridge in 
about 24 hours, south to southwesterly shear is expected to 
increase as the cyclone moves over even cooler waters and ingests 
increasingly dry air. This will lead to the demise of the cyclone, 
and Karina is expected to degenerate to a remnant low in a couple 
of days, dissipating shortly thereafter. 

As the system weakens, it will be steered by the low-level 
northeasterly trade wind flow supplied by a surface high centered to 
the distant northwest, causing a slowing in forward speed, and a 
turn toward the west and southwest. The new official track forecast 
has changed little from the previous, and lies very close to the 
dynamical consensus TVCE. The new intensity forecast is little 
changed, and closely follows both the statistical and dynamical 
guidance. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  16/0300Z 21.3N 123.0W   50 KT  60 MPH
 12H  16/1200Z 22.1N 124.2W   45 KT  50 MPH
 24H  17/0000Z 23.0N 125.6W   40 KT  45 MPH
 36H  17/1200Z 23.4N 126.7W   35 KT  40 MPH
 48H  18/0000Z 23.5N 127.8W   30 KT  35 MPH
 60H  18/1200Z 23.2N 129.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  19/0000Z 22.5N 130.2W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  20/0000Z...DISSIPATED
 
$$
Forecaster Birchard