Eastern Pacific Basin Tropical Cyclones

Hurricane Kay Forecast Discussion


000
WTPZ42 KNHC 081443
TCDEP2

Hurricane Kay Discussion Number  17
NWS National Hurricane Center Miami FL       EP122022
900 AM MDT Thu Sep 08 2022

Kay continues to lose organization in satellite imagery, as there
is no longer an eye present and the central convection continues to
decrease.  The various subjective and objective satellite intensity
estimates are in the 65-77 kt range, and based on this the initial
intensity is held at a possibly generous 75 kt.  An Air Force
Reserve Hurricane Hunter aircraft is currently enroute to
investigate Kay.

Kay is now over 23C sea surface temperatures and will be traversing
progressively cooler SSTs over the next couple of days.  That,
along with land interaction and a gradually drying mid-level air
mass, is expected to cause gradual weakening over the next couple of
days. However, Kay is forecast to remain a hurricane when it passes
near or over the west-central coast of the Baja California peninsula
in about 12 h, and remain a tropical storm as it passes just west
of the northwestern portion of the peninsula on Friday.  The cyclone
is expected to lose its convection and become post-tropical between 
48-60 h, and then decay to a remnant low pressure area by 72 h.

Kay continues to move north-northwestward or 345/13 kt. There is no 
change to the previous track forecast philosophy.  A mid-level 
ridge to the east of Kay should steer it on a north-northwestward
heading during the next 24 to 36 hours.  After that time, a weaker
and more vertically shallow Kay is expected to turn more westward,
and eventually southward to the southeast of a low-level ridge over
the eastern Pacific.  The track guidance has changed little since 
the last advisory, so the new track forecast has only minor 
adjustments from the previous forecast.

Kay remains a very large tropical cyclone. It is producing an 
extensive area of high seas, with swells affecting portions of 
southwestern Mexico, the Gulf of California, and the Baja California 
peninsula.  Although Kay is likely to weaken before it makes 
landfall or moves very close 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. As the center of Kay passes just offshore, heavy rainfall could 
lead to flash flooding, including landslides, across the Baja 
California peninsula and portions of mainland northwestern Mexico 
through Saturday morning.  Flash, urban, and small stream flooding 
is likely across Southern California beginning Friday, especially in 
and near the peninsular ranges. Flash, urban, and small stream 
flooding is possible beginning Friday in Southwest Arizona.

2. Hurricane conditions are expected along portions of the
west-central Baja California coast later this morning through
this evening, and a hurricane warning is in effect for that area.

3. Tropical storm conditions are occurring over portions of the
Baja California peninsula, and these conditions are expected
to spread northward during the next day or so, where a
Tropical Storm Warning is in effect.


FORECAST POSITIONS AND MAX WINDS

INIT  08/1500Z 25.8N 113.8W   75 KT  85 MPH
 12H  09/0000Z 27.6N 114.6W   65 KT  75 MPH...INLAND
 24H  09/1200Z 29.6N 116.0W   55 KT  65 MPH...OVER WATER
 36H  10/0000Z 30.9N 117.5W   45 KT  50 MPH
 48H  10/1200Z 31.5N 118.9W   40 KT  45 MPH
 60H  11/0000Z 31.7N 119.9W   35 KT  40 MPH...POST-TROPICAL
 72H  11/1200Z 31.3N 120.8W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  12/1200Z 30.0N 121.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  13/1200Z 28.5N 120.0W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Beven



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