000
WTPZ43 KNHC 151454
TCDEP3

Hurricane Kiko Discussion Number  13
NWS National Hurricane Center Miami FL       EP132019
800 AM PDT Sun Sep 15 2019

Kiko has become a very powerful hurricane overnight, with a warm eye
and strong eyewall convection. The cloud pattern is also fairly
symmetric, except favoring the western semicircle slightly due to
some easterly shear.  The initial wind speed is set to 115 kt, which
matches the latest ADT and TAFB estimates.

The hurricane should be near its peak intensity today while it in is
a low-shear, marginal warm-water environment. While those conditions
don't change that much during the next few days, Kiko is forecast
to be moving fairly slowly over that time, which will likely stir up
some cooler waters and help weaken the convection.  A steadier
weakening is expected at long-range due to an increase in shear. The
new forecast is somewhat lower than the last one, but higher than
the model consensus.  It isn't out of the realm of possibility that
Kiko could transition into an annular hurricane, which tend to
maintain their intensities higher than average, so I'm hesitant to
reduce the forecast too much for now.

Kiko is moving westward at about 6 kt.  A mid-level ridge to the
north of the cyclone is forecast to remain in place for about the
next two days, keeping the hurricane on a slow westward track.  A
weakness or even a break in the ridge is then forecast by all of the
models due to a mid-latitude trough, with perhaps a restrengthening
of the ridge at long range.  There's been a subtle model trend
toward supporting the ridge remaining weak but intact, which would
favor Kiko moving very slowly westward instead of any significant
rightward turn.  The latest NHC prediction places a greater weight
on the UKMET and ECMWF models and their ensembles, which generally
favor the weak ridge scenario.  No significant changes were made to
the previous forecast track, but the long-range track confidence is
low due to the large model spread at that time.

FORECAST POSITIONS AND MAX WINDS

INIT  15/1500Z 17.0N 121.1W  115 KT 130 MPH
 12H  16/0000Z 17.1N 122.0W  110 KT 125 MPH
 24H  16/1200Z 17.3N 123.2W  105 KT 120 MPH
 36H  17/0000Z 17.4N 124.1W   95 KT 110 MPH
 48H  17/1200Z 17.5N 125.0W   85 KT 100 MPH
 72H  18/1200Z 17.5N 126.7W   70 KT  80 MPH
 96H  19/1200Z 18.0N 129.0W   65 KT  75 MPH
120H  20/1200Z 18.5N 131.5W   50 KT  60 MPH

$$
Forecaster Blake