Tropical Storm Kristy Forecast Discussion

050 
WTPZ42 KNHC 220835
TCDEP2

Tropical Storm Kristy Discussion Number   3
NWS National Hurricane Center Miami FL       EP122024
300 AM CST Tue Oct 22 2024

Satellite images indicate that Kristy has continued to gradually 
become better organized during the overnight hours.  A convective 
burst has been occurring over the low-level center, an indication 
that a central core could be forming.  The cyclone also has some 
impressive curved banding to the north and west, although these 
bands are a bit far from the center.  A pair of ASCAT passes from 
22/0346 UTC and 22/0441 UTC showed tropical storm force winds in 
the northern semi-circle, with vectors in the 35 to 38 kt range.  
Since the time of the ASCAT passes, Kristy's convection has become 
better organized, with latest subjective Dvorak intensity estimates 
from TAFB and SAB at a consensus T-3.0/45 kt.  The initial intensity 
is nudged upward to 45 kt for this advisory.

Kristy is estimated to be moving west-northwestward, or 285/13 kt. 
A strong subtropical ridge to the north of the cyclone will steer 
it westward for the next 3 days or so.  Friday into the weekend, a 
turn to the west-northwest or northwest is expected as Kristy rounds 
the western periphery of the mid to upper-level ridge, and a 
mid-latitude upper-level trough approaches from the west.  The track 
forecast is largely unchanged from the previous official forecast 
and lies in the middle of the guidance envelope.  It should be noted 
that there is quite a bit of spread in the track guidance at days 4 
and 5, so confidence in this part of the forecast is a bit below 
average.

Environmental conditions are favorable for steady strengthening, 
and rapid intensification cannot be ruled out.  For the next 
72 h, Kristy will remain within an environment of warm ocean 
temperatures, relatively weak vertical wind shear, and a moist 
troposphere.  Beyond 72 h, southerly or southwesterly vertical wind 
shear will begin to increase over the cyclone, becoming strong in 4 
to 5 days.  Kristy should also cross the 26C isotherm in about 4 
days and move into a much more stable environment.  Therefore, 
weakening should begin in 3 to 4 days, with the potential for rapid 
weakening in 4 to 5 days.  The intensity forecast is largely 
unchanged from the previous prediction, which calls for Kristy to 
peak at 100 kt in a few days, and lies near the middle of the 
guidance envelope.


FORECAST POSITIONS AND MAX WINDS

INIT  22/0900Z 14.2N 104.8W   45 KT  50 MPH
 12H  22/1800Z 14.3N 107.1W   60 KT  70 MPH
 24H  23/0600Z 14.4N 110.4W   70 KT  80 MPH
 36H  23/1800Z 14.3N 113.8W   85 KT 100 MPH
 48H  24/0600Z 14.2N 117.2W   95 KT 110 MPH
 60H  24/1800Z 14.3N 120.3W  100 KT 115 MPH
 72H  25/0600Z 14.8N 123.0W  100 KT 115 MPH
 96H  26/0600Z 17.1N 127.9W   90 KT 105 MPH
120H  27/0600Z 20.3N 131.6W   65 KT  75 MPH

$$
Forecaster Hagen