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Tropical Storm Agatha Discussion Number   6
NWS National Hurricane Center Miami FL       EP012022
400 AM CDT Sun May 29 2022

During the past several hours, Agatha has somewhat shaken off the 
effects of shear and dry air intrusion noted in the last advisory.  
The convective pattern has improved in infrared satellite imagery, 
and just-received GMI microwave data show that the low- and 
mid-level centers have become better aligned.  In addition, 37 GHz 
microwave data show improved low-level convective banding near the 
center, although there is not a closed ring of convection at this 
time.  The initial intensity is increased to 60 kt based on a blend 
of the subjective Dvorak satellite intensity estimates from TAFB and 
SAB along with the CIMSS ADT and satellite consensus estimates.

The motion has continued to be a bit erratic during the past several 
hours, with the current motion estimated at 330/3 kt.  Agatha is 
expected to turn northeastward later today as it becomes embedded in 
southwesterly flow between a mid- to upper-level trough over 
northern Mexico and a mid- to upper-level ridge to the east of the 
cyclone.  This motion should bring the center of Agatha over the 
coast of southern Mexico on Monday.  The track guidance is in good 
agreement on this scenario, although the latest model runs are a 
little slower than the previous runs.  The new forecast track is in 
the middle of the guidance envelope and has only minor adjustments 
from the previous forecast.

The intensity forecast has gotten a little more uncertain.  It now 
appears that Agatha will experience light to moderate westerly shear 
until landfall, which is somewhat less favorable of an environment 
than previously expected.  However, the storm is in a generally 
moist environment with significant upper-level divergence, and it is 
over warm sea surface temperatures.  While the intensity guidance 
has again trended slightly lower, the rapid intensification index of 
the SHIPS model continues to indicate high probabilities of rapid 
strengthening, with a 55-60 percent chance of a 45-kt increase 
between now and landfall.  Given the uncertainty, the intensity 
forecast is again nudged slightly downward to follow the upper edge 
of the intensity guidance.  However, it is possible it is 
conservative.  After landfall, Agatha is expected to quickly weaken 
and dissipate as it crosses Mexico.
 
Key Messages:
 
1. Dangerous coastal flooding from storm surge accompanied by large
and destructive waves is expected near and the east of where Agatha
makes landfall.
 
2. Hurricane conditions are expected in the hurricane warning area
in southern Mexico on Monday, with tropical storm conditions
beginning there tonight.  Tropical storm conditions are expected in 
the tropical storm warning area on Monday.
 
3. Heavy rains associated with Agatha will develop over portions of 
southern Mexico later today and continue through Tuesday. This will 
pose a threat of potentially life-threatening flash flooding and 
mudslides.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  29/0900Z 14.1N  98.8W   60 KT  70 MPH
 12H  29/1800Z 14.4N  98.7W   65 KT  75 MPH
 24H  30/0600Z 14.9N  98.0W   75 KT  85 MPH
 36H  30/1800Z 15.5N  97.1W   80 KT  90 MPH
 48H  31/0600Z 16.3N  96.1W   55 KT  65 MPH...INLAND
 60H  31/1800Z 17.1N  95.1W   25 KT  30 MPH...INLAND
 72H  01/0600Z...DISSIPATED
 
$$
Forecaster Beven
 
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