000
WTNT42 KNHC 252037
TCDAT2

Tropical Storm Karen Discussion Number  15
NWS National Hurricane Center Miami FL       AL122019
500 PM AST Wed Sep 25 2019

An Air Force Reserve Hurricane Hunter aircraft investigating Karen
found maximum 850-mb flight-level winds of 43 kt, and SFMR-measured
winds of 34 kt.  Although those surface winds were coincident with
some heavy rains, which makes them questionable, it is assumed that
there are still some tropical-storm-force winds somewhere within
the circulation.  The initial intensity has been lowered to 35 kt.

Karen has turned toward the north-northeast with an initial motion
of 015/12 kt.  The cyclone is positioned between a mid-level high
centered over the central Atlantic and a mid- to upper-level low
spinning just east of the Bahamas.  The steering flow between these
two features should keep Karen on a generally northeastward
trajectory during the next 48 hours.  Around that time, a blocking
ridge is expected to build to the north of Karen, causing it to make
a clockwise loop and move west-southwestward by days 4 and 5.
Compared to the previous cycle, the track models are allowing Karen
to get farther to the northeast before it makes its loop, which ends
up slowing down the 4- and 5-day NHC forecast points.  Even with
that change, however, the forecast path of Karen is relatively
unchanged from before.

It's probably time to put more weight on the dynamical models for
Karen's future intensity.  The cyclone has continued to struggle
in its environment, which is essentially what those models have been
indicating all along.  Even the statistical-dynamical models, which
are explicitly showing strengthening, indicate that the environment
won't be very favorable, with convergence aloft and a dry mid-level
air mass.  Because of those factors, and the lower initial
intensity, the NHC intensity forecast has been lowered considerably
from this morning's forecast.  It still allows for the possibility
of some strengthening, but if model trends continue, the official
forecast could be lowered further in subsequent advisories.  And if
the global models are correct, Karen could even lose deep
convection, and hence become post-tropical, in about 3 days.


FORECAST POSITIONS AND MAX WINDS

INIT  25/2100Z 22.9N  64.3W   35 KT  40 MPH
 12H  26/0600Z 24.6N  63.9W   35 KT  40 MPH
 24H  26/1800Z 26.5N  63.0W   35 KT  40 MPH
 36H  27/0600Z 27.6N  61.8W   40 KT  45 MPH
 48H  27/1800Z 27.9N  60.8W   40 KT  45 MPH
 72H  28/1800Z 27.5N  60.5W   40 KT  45 MPH
 96H  29/1800Z 26.5N  63.5W   40 KT  45 MPH
120H  30/1800Z 26.0N  67.0W   35 KT  40 MPH

$$
Forecaster Berg