Eastern Pacific Basin Tropical Cyclones

Tropical Storm Kay Forecast Discussion


009 
WTPZ42 KNHC 042036
TCDEP2

Tropical Storm Kay Discussion Number   2
NWS National Hurricane Center Miami FL       EP122022
400 PM CDT Sun Sep 04 2022

Satellite data indicate that the depression has strengthened into 
Tropical Storm Kay.  Although the convective pattern is still a bit 
ragged, banding features have improved on the south side of the 
cyclone. A pair of ASCAT passes from a few hours ago showed peak 
winds around 35 kt to the northeast of the center.  Based on that 
data and the T2.5 Dvorak classification from TAFB, the initial 
intensity is increased a little to 35 kt.  Kay is a large storm with 
its cloud field extending several hundred miles across, and some of 
the outer bands are moving across the coast of southwestern Mexico.

The center is located a little to the north of the previous track, 
and the estimated motion is now 290/11 kt. This general motion is 
expected to continue for the next couple of days, keeping the core 
of the system south of the coast of southwestern Mexico during that 
time.  Thereafter, the models all show a turn to the northwest and 
then the north.  Overall, there has been little change in the model 
guidance this cycle and the solutions remain relatively tightly 
clustered.  Despite the tightly-clustered guidance, the GFS and 
ECMWF ensemble spreads encompass as far east as the Gulf of 
California and as far west as a few hundred miles west of the Baja 
California peninsula.  The NHC track forecast is a little to the 
north of the previous one in the short term, due to the initial 
position and motion, but ends up close to the previous track beyond 
48 h.

Kay is likely to strengthen during the next few days while it 
remains over warm water and embedded in a very moist environment. 
Although the Rapid Intensification Indices in the SHIPS model are 
relatively high, rapid intensification in the short term appears 
unlikely given the broad structure of the cyclone and expected 
moderate shear.  The new NHC intensity forecast is largely 
consistent with the previous one and shows steady strengthening 
during the next 2 to 3 days.  Beyond that time, weakening is 
expected due to cooler SSTs.  Regardless of the details, Kay is 
expected to be a significant hurricane near Baja in a few days.

KEY MESSAGES:

1. Although Kay is expected to stay offshore, heavy rainfall could
lead to localized flash flooding in portions of southwestern Mexico.

2. Interests in the Baja California peninsula should closely monitor 
Kay as tropical storm or hurricane watches could be required tonight 
or on Monday.


FORECAST POSITIONS AND MAX WINDS

INIT  04/2100Z 14.8N 102.5W   35 KT  40 MPH
 12H  05/0600Z 15.1N 104.1W   45 KT  50 MPH
 24H  05/1800Z 15.6N 106.0W   55 KT  65 MPH
 36H  06/0600Z 16.4N 107.8W   65 KT  75 MPH
 48H  06/1800Z 17.6N 109.5W   75 KT  85 MPH
 60H  07/0600Z 19.2N 110.9W   85 KT 100 MPH
 72H  07/1800Z 21.1N 112.0W   85 KT 100 MPH
 96H  08/1800Z 24.9N 113.6W   75 KT  85 MPH
120H  09/1800Z 28.3N 115.5W   55 KT  65 MPH

$$
Forecaster Cangialosi




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