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Remnants Of Kate Discussion Number  19
NWS National Hurricane Center Miami FL       AL102021
500 PM AST Wed Sep 01 2021
 
Kate's structure this afternoon has deteriorated further. While
occasional bursts of deep convection are still occuring to the south
of a broad area of low-level cyclonic rotation, this activity lacks
much organization. Recent visible satellite imagery also suggests
that the low-level circulation is in the process of opening up into
a trough, with little if any northerly cloud motions being observed
to the west of the estimated center. In addition, I have been
fortunate to receive some in-situ data from the NASA-DC8 aircraft
that earlier preformed a research mission into Kate. Dropsonde data
launched near the center indicated that the surface pressure was
near 1012 mb, which is only a few millibars lower than the
environmental ambient pressure. The dropsondes launched west of the
center also failed to find any northerly surface winds. The
combination of these data suggest that Kate's center is losing
definition and no longer possesses a well-defined circulation.
Therefore, the system no longer meets the definition of a tropical
cyclone, and this will be the final advisory. Maximum sustained
winds have also been lowered to 25-kt based on the surface winds
from dropsonde data provided by the DC8 aircraft to the east of the
center.
 
The remnants of Kate have accelerated to the north-northwest today
with the estimated motion at 340/13 kt, likely as the low-level
vorticity maxima has become fully decoupled from the mid-level
vortex located well to the south and east. This motion should
continue until Kate completely fades away while embedded in
the synoptic environment near a low-level subtropical ridge.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  01/2100Z 28.5N  52.9W   25 KT  30 MPH
 12H  02/0600Z...DISSIPATED
 
$$
Forecaster Papin
 
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