Pacific Hurricane and Tropical Cyclone Track Updates

Hurricane Rick Forecast Discussion



735 
WTPZ42 KNHC 240839 CCA
TCDEP2

Hurricane Rick Discussion Number   8...Corrected
NWS National Hurricane Center Miami FL       EP172021
400 AM CDT Sun Oct 24 2021

Corrected typo in the first Key Message 

The overall satellite presentation of the hurricane has not changed
much overnight.  Rick's center is embedded within a small central
dense overcast, and an earlier SSMIS microwave overpass suggests
that the small eye was slightly better defined. An Air Force Reserve
Hurricane Hunter aircraft investigating Rick overnight has found
that the hurricane has not strengthened since the mission yesterday
afternoon.  Although the aircraft did not measure flight-level winds
as strong as during the previous mission, a dropsonde released in
the southwestern eyewall measure mean winds in the lowest 150 m that
still support an intensity of 75 kt.  The aircraft reported that the
minimum pressure is around 980 mb, which is close to the pressure
reported yesterday afternoon.

It is surprising that Rick has not intensified over the past 6-12
hours as the hurricane remains in a low shear environment and the
outflow is well established.  Given the expected favorable
upper-level wind pattern and warm sea surface temperatures along the
track of Rick, strengthening is forecast to resume today.  Since
Rick has not strengthened as much as expected and it only has about
12-18 hours before southwesterly shear is forecast to increase over
the storm, the updated intensity forecast calls for a lower peak
intensity than before and is at the high end of the guidance
envelope.  As Rick approaches the coast of southern Mexico tonight,
the aforementioned increase in southwesterly shear and land
interaction could case some weakening.  After landfall, rapid
weakening will occur as the cyclone moves over the mountainous
terrain of Mexico, and Rick is expected to dissipate Monday night or
Tuesday.

The overnight aircraft fixes were a little east of the earlier
satellite-based position estimates, yielding a more northward
long-term motion estimate of 355/3 kt.  Rick is forecast to move
northward or north-northwestward at a slightly faster forward speed
toward a weakness in the subtropical ridge over Mexico.  This motion
should bring the center of the hurricane to the coast of southern
Mexico within the hurricane warning area tonight or early Monday,
and inland over southern or southwestern Mexico on Monday.  The
dynamical models are in relatively good agreement on this scenario,
and the official forecast lies near the various consensus aids.  The
new track forecast is a little right of the previous advisory due to
the more eastward initial position.


Key Messages:

1. Rick is forecast to strengthen today and reach the coast of
southern Mexico tonight or early Monday, bringing life-threatening
storm surge and dangerous hurricane-force winds within a portion of
the Hurricane Warning area from Tecpan de Galeana to Punta San
Telmo.  Residents in this area should follow any advice given by
local officials.

2. Rick is expected to bring tropical storm conditions to portions
of the southern and southwestern coasts of Mexico beginning today
from east of Tecpan de Galeana to Acapulco, and by Monday morning
from west of Punta San Telmo to Manzanillo, where a Tropical
Storm Warning is in effect.

3. Heavy rains associated with Rick are expected to move into the
Mexican states of Guerrero and Michoacan today, and could persist
through Monday night.  This rainfall will likely produce flash
flooding and mudslides.


FORECAST POSITIONS AND MAX WINDS

INIT  24/0900Z 15.6N 101.7W   75 KT  85 MPH
 12H  24/1800Z 16.2N 101.8W   90 KT 105 MPH
 24H  25/0600Z 17.2N 102.0W   85 KT 100 MPH
 36H  25/1800Z 18.4N 102.6W   60 KT  70 MPH...INLAND
 48H  26/0600Z 20.2N 103.7W   30 KT  35 MPH...POST-TROP/INLAND
 60H  26/1800Z...DISSIPATED

$$
Forecaster Brown




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