Eastern Pacific Basin Tropical Cyclones

Tropical Storm Agatha Forecast Discussion


000
WTPZ41 KNHC 280858
TCDEP1

Tropical Storm Agatha Discussion Number   2
NWS National Hurricane Center Miami FL       EP012022
400 AM CDT Sat May 28 2022

Convection associated with Tropical Depression One-E has become 
better organized since the last advisory, with a small central 
dense overcast forming and increasing outer banding in the 
southeastern semicircle.  Satellite intensity estimates from SAB 
and TAFB were 30 and 35 kt at 06Z, and based on the increased 
organization since that time the initial intensity is increased to 
35 kt.  Thus, the depression is being upgraded to Tropical Storm 
Agatha.

Agatha has slowed its forward speed with the initial motion now 
270/3 kt.  The combination of a mid- to upper-level trough moving 
eastward across northern Mexico and a mid- to upper-level ridge 
building east of the storm should cause Agatha to turn 
northwestward during the next 12 h or so, followed by recurvature to 
the northeast.  This track should bring the center of the cyclone 
near or over the southern coast of Mexico between the 48-60 h 
points.  The guidance is in generally good agreement on this 
scenario, although there is some spread near landfall due to 
differences on how the track guidance models have Agatha 
interacting with the Mexican mountains.  The new forecast track is 
in the center of the guidance envelope and has only minor 
adjustments from the previous forecast.

Agatha is expected to be in a moist environment with light wind 
shear, significant upper-level divergence, and warm sea surface 
temperatures until landfall.  This should allow steady to rapid 
strengthening, and the SHIPS model rapid intensification index 
shows a 70 percent chance of the storm strengthening 55 kt during 
the next 48 h.  The intensity forecast thus calls for the cyclone 
to strengthen to a possibly conservative peak intensity of 85 kt by 
60 h, which is at the upper edge of the guidance envelope.  Rapid 
weakening is expected after landfall as Agatha moves over the 
mountains of southern Mexico.  There is a possibility that the 
remnants of Agatha could emerge over the Bay of Campeche by 120 h, 
but at this time it appears unlikely the system will still be a 
tropical cyclone.

A Hurricane Watch has been issued for portions of the southern 
coast of Mexico.  Additional watches and warnings will be required 
for this area later today.

Key Messages:

1. There is an increasing risk of tropical-storm-force and
hurricane-force winds along portions of the southern coast of Mexico
in the next two to three days, and a Hurricane Watch is now in 
effect for portions of this area.  Interests in this area should 
closely monitor the progress of this system and updates to the 
forecast.

2. Heavy rains associated with Agatha will develop over portions of 
southern Mexico by Sunday and continue through Tuesday.  This will 
pose a threat of potentially life-threatening flash flooding and 
mudslides.


FORECAST POSITIONS AND MAX WINDS

INIT  28/0900Z 12.9N  98.1W   35 KT  40 MPH
 12H  28/1800Z 13.0N  98.5W   45 KT  50 MPH
 24H  29/0600Z 13.4N  98.7W   60 KT  70 MPH
 36H  29/1800Z 13.9N  98.6W   70 KT  80 MPH
 48H  30/0600Z 14.6N  98.1W   80 KT  90 MPH
 60H  30/1800Z 15.3N  97.3W   85 KT 100 MPH
 72H  31/0600Z 16.2N  96.2W   65 KT  75 MPH...INLAND
 96H  01/0600Z 17.9N  94.7W   25 KT  30 MPH...INLAND
120H  02/0600Z...DISSIPATED

$$
Forecaster Beven/Bucci



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