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Tropical Storm Karina Discussion Number   6
NWS National Hurricane Center Miami FL       EP162020
200 AM PDT Mon Sep 14 2020

Karina continues to be a sheared cyclone with the deep convection 
displaced to the southwest of the exposed low-level center.  Recent 
scatterometer data showed winds up to 40 kt in the southern 
semicircle, and thus the initial intensity remains 40 kt.

The cyclone has moved more westward during the past several hours, 
possibly due to reformation of the center closer to the convection. 
This motion of 280/11 is expected to be short-lived, as all of the 
available track guidance indicates that Karina should turn 
northwestward during the next 24 h, with a northwestward to 
west-northwestward then expected through 96 h. After that, the 
cyclone or its remnants are expected to turn back to the west.  The 
new forecast track is adjusted to the west of the previous track 
based on the current position and motion, and it lies a bit to the 
left of the various consensus models.  The 96 h point has been 
nudged a little to the north of the previous forecast based on a 
northward shift of the guidance at that time.

While Karina is likely to continue to feel the effects of 
northeasterly vertical shear for the next 36 h or so, the new 
forecast track gives it a little more time over warmer water.  
Thus, the intensity forecast keeps the door open for some 
strengthening for 24 h or so.  After that, the center should move 
over cooler water, which should cause the cyclone to weaken to a 
remnant low by 96 h and dissipate by 120 h.  The new intensity 
forecast has only minor tweaks from the previous forecast.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  14/0900Z 17.9N 118.2W   40 KT  45 MPH
 12H  14/1800Z 18.4N 119.3W   45 KT  50 MPH
 24H  15/0600Z 19.3N 120.5W   45 KT  50 MPH
 36H  15/1800Z 20.2N 121.8W   40 KT  45 MPH
 48H  16/0600Z 21.3N 123.2W   35 KT  40 MPH
 60H  16/1800Z 22.0N 124.6W   30 KT  35 MPH
 72H  17/0600Z 22.6N 125.7W   30 KT  35 MPH
 96H  18/0600Z 23.0N 127.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  19/0600Z...DISSIPATED
 
$$
Forecaster Beven
 
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