Eastern Pacific Basin Tropical Cyclones

Hurricane Kay Forecast Discussion


000
WTPZ42 KNHC 070856
TCDEP2

Hurricane Kay Discussion Number  12
NWS National Hurricane Center Miami FL       EP122022
300 AM MDT Wed Sep 07 2022

Kay appears to be slightly better organized in satellite imagery
this morning with an eye that has become a little better defined
and a convective band with cloud tops as cold as -70 to -80C
wrapping around the center.  There is a larger-than-normal spread
between the subjective and objective Dvorak estimates this morning
so there is more uncertainty regarding the hurricane's initial
intensity than usual.  The initial intensity has been raised to
85 kt, commensurate with the recent increase in organization.  An
Air Force Reserve reconnaissance aircraft is scheduled to
investigate Kay this afternoon.

Kay is located over sea surface temperatures of 28-29 degrees
Celsius, and the vertical wind shear has decreased over the past 24
hours and become less than 10 kt over the storm.  These conditions 
should allow for some strengthening today. By tonight, Kay will be 
moving over decreasing SSTs, and a weakening trend should begin 
shortly thereafter.  However, Kay is expected to remain a hurricane 
when it passes near the west-central coast of the Baja peninsula on 
Thursday and Thursday night.  After that time, sharply decreasing 
SSTs should produce a faster rate of weakening, and Kay is forecast 
to become a post-tropical cyclone after it passes near northern Baja 
California by day 4. The NHC intensity forecast is above most of 
the guidance at 12 hours, and then closely follows the SHIPS model 
during the weakening phase of the forecast.

Kay has turned north-northwestward and is moving 330/10 kt.  A 
ridge to the east of Kay should steer the storm north-northwestward 
during the next few days.  This will take the core of the hurricane 
near the west-central coast of Baja California on Thursday and 
Friday.  After that time, low-level ridging to the north of Kay 
should cause it to turn westward as it weakens.  The GFS and its 
ensemble mean remain along the east side of the guidance envelope 
while the ECMWF is closer to the center.  The NHC track lies 
between those typically reliable models and is between the TVCE 
and HFIP consensus aids. The updated track is slightly to the right 
of the previous advisory. 

Kay is a very large tropical cyclone.  It is producing an extensive
area of high seas, with swells affecting portions of southwestern
Mexico and the southern Baja California peninsula.  Although Kay is
likely to weaken before it makes its closest approach to the
west-central coast of the Baja peninsula, it is forecast to remain a
large and dangerous hurricane through that time.  In addition, high
wind, surf, and rainfall impacts will extend far from the center so
users should not focus on the exact forecast track.

KEY MESSAGES:

1. Heavy rainfall could lead to flash flooding, including 
landslides, across the Baja California peninsula and portions of 
mainland northwestern Mexico through Saturday morning.  Flash 
flooding is possible across the peninsular ranges of Southern 
California Friday night into Saturday morning.

2. Hurricane conditions are expected along portions of the
west-central Baja California coast on Thursday and Thursday night, 
and a hurricane warning is in effect for that area. 

3. Tropical storm conditions are expected over portions of the
Baja California peninsula beginning this morning, where a
Tropical Storm Warning is in effect.


FORECAST POSITIONS AND MAX WINDS

INIT  07/0900Z 20.2N 112.0W   85 KT 100 MPH
 12H  07/1800Z 21.6N 112.8W   90 KT 105 MPH
 24H  08/0600Z 23.7N 113.6W   85 KT 100 MPH
 36H  08/1800Z 26.0N 114.5W   80 KT  90 MPH
 48H  09/0600Z 27.9N 115.6W   70 KT  80 MPH
 60H  09/1800Z 29.7N 116.8W   55 KT  65 MPH
 72H  10/0600Z 30.8N 118.2W   40 KT  45 MPH
 96H  11/0600Z 31.2N 120.6W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  12/0600Z 30.1N 121.6W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Brown



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