000
WTNT42 KNHC 262035
TCDAT2

Tropical Storm Karen Discussion Number  19
NWS National Hurricane Center Miami FL       AL122019
500 PM AST Thu Sep 26 2019

Data from aircraft reconnaissance, ASCAT, and NOAA buoy 41049
indicate that Karen's circulation is becoming increasingly
elongated.  A combination of data from these platforms also
supports maintaining an initial intensity of 40 kt for now.  The
deterioration of Karen's structure suggests that weakening is
imminent, especially with an expected increase in northerly shear
during the next day or so.  The GFS and ECMWF models--via their
simulated infrared satellite fields--are unanimous in showing Karen
losing its organized deep convection in about 36 hours.  Based on
that, the new NHC forecast depicts Karen as becoming a remnant low
in 48 hours.  Due to a significant increase in southwesterly shear
by day 4, the system is expected to open up into a surface trough by
day 5.

Fixes suggest that Karen is slowing down a bit and turning to the
right, with an initial motion of 025/10 kt.  The steering flow will
be evolving over the next couple of days with high pressure
building to the north of Karen over the western Atlantic.  This
will cause the cyclone to almost come to a stop in about 36 hours,
and then turn to the west by 48 hours until dissipation on day 5.
This is the same forecast reasoning as before, and the new NHC
forecast is just an update of the previous one.


FORECAST POSITIONS AND MAX WINDS

INIT  26/2100Z 27.2N  62.9W   40 KT  45 MPH
 12H  27/0600Z 27.9N  61.8W   35 KT  40 MPH
 24H  27/1800Z 28.2N  60.6W   35 KT  40 MPH
 36H  28/0600Z 28.1N  60.3W   30 KT  35 MPH
 48H  28/1800Z 28.0N  61.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  29/1800Z 27.9N  63.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  30/1800Z 27.9N  66.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  01/1800Z...DISSIPATED

$$
Forecaster Berg