Eastern Pacific Basin Tropical Cyclones

Tropical Storm Agatha Forecast Discussion


000
WTPZ41 KNHC 290236
TCDEP1

Tropical Storm Agatha Discussion Number   5
NWS National Hurricane Center Miami FL       EP012022
1000 PM CDT Sat May 28 2022

Conventional satellite imagery would suggest that Agatha has 
continued to intensify, with a strong burst of convection near the 
center.  However, microwave data from the past few hours suggest 
that the structure of Agatha has actually degraded since the last 
advisory.  This data reveals that the low- and mid-level centers of 
the tropical cyclone are not well-aligned, and the small core seen 
earlier has become less distinct.  While the recent Dvorak 
estimates have risen slightly, I'm inclined to leave the intensity 
at 50 kt for this cycle given the microwave information.

It seems like a bit of dry air along with some mid-level shear are 
potentially the reasons for the pause in intensification.  This is 
only expected to be a short-term trend, since the environment 
generally looks to support more strengthening due to substantial 
mid-level moisture in the storm's path along with plenty of warm 
SSTs and low shear.  The model guidance has trended lower on this 
cycle, perhaps placing too much emphasis on the recent lack of 
intensification.  The new forecast is slightly lower than the 
previous one, about 5 kt, but is higher than any of the guidance on 
this cycle, owing to continuity and seemingly conducive large-scale 
conditions before landfall.

The center of Agatha continues to wobble or even re-form near the 
deepest convection, with a long-term motion estimate of 325/3 kt.  
The storm should turn northeastward tomorrow and accelerate due to 
it becoming embedded in low- to middle-level southwesterly flow.  
Recent guidance has shifted somewhat westward near landfall in 
southern Mexico, but this is mostly due to the more westward 
initial position.  The latest NHC track forecast is nudged westward 
near Mexico, lying between the GFS and dynamical model consensus 
TVCE.  Agatha should dissipate over the higher terrain of Mexico in 
about 3 days, although the remnants are likely to move over the 
southwestern Gulf and the Yucatan Peninsula around the middle of 
next week.

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 Sunday night.  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 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  29/0300Z 13.9N  98.7W   50 KT  60 MPH
 12H  29/1200Z 14.1N  98.8W   60 KT  70 MPH
 24H  30/0000Z 14.6N  98.2W   75 KT  85 MPH
 36H  30/1200Z 15.2N  97.4W   85 KT 100 MPH
 48H  31/0000Z 15.9N  96.4W   60 KT  70 MPH...INLAND
 60H  31/1200Z 16.7N  95.4W   30 KT  35 MPH...INLAND
 72H  01/0000Z...DISSIPATED

$$
Forecaster Blake



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