Hurricane Agatha Discussion Number 10
NWS National Hurricane Center Miami FL EP012022
400 AM CDT Mon May 30 2022
Agatha's satellite presentation has remained fairly steady state
since last evening. The center is embedded beneath a compact
central dense overcast, but there have been no microwave satellite
passes overnight to provide a better view of the hurricane's
structure. Dvorak estimates from TAFB and SAB are also steady,
remaining at T5.0, so Agatha's initial intensity is being held at
what the Air Force Reserve Hurricane Hunter found yesterday--95 kt.
A second and final Hurricane Hunter mission is scheduled for later
this morning, assuming the center isn't too close to the coast and
the plane can navigate a safe distance away from the nearby
mountainous terrain.
We did receive two ASCAT passes a few hours ago, which indicated
that tropical-storm-force winds have begun along the coast of
Oaxaca. The scatterometers also helped to refine Agatha's position,
and the initial motion remains slowly northeastward, or 055/5 kt.
This northeastward motion is expected to continue today, and
Agatha's center should cross the coast of Oaxaca within the next
12-18 hours. The center, or Agatha's remnants, should then continue
northeastward over the Isthmus of Tehuantepec. There have been no
notable shifts in the latest track guidance, thus the new NHC
forecast is very similar to the previous one.
Agatha has another 12 hours or so to take advantage of warm 29
degree Celsius waters. However, the hurricane doesn't seem to have
been able to benefit from the waters during the previous 12 hours,
and it's not entirely clear if it will strengthen before landfall.
One potential negative influence is the nearby coastal mountains of
southern Mexico, which are likely to disrupt the low-level
circulation of the relatively small hurricane. Nearly all of the
intensity models show Agatha weakening immediately, but the NHC
forecast will maintain a steady intensity up until landfall, with
rapid weakening occurring once Agatha makes landfall and moves over
the rough terrain. This forecast does not preclude the possibility
of some intensification before landfall. Dissipation of Agatha's
surface circulation over southern Mexico is now expected by 48
hours.
Key Messages:
1. Extremely dangerous coastal flooding from storm surge,
accompanied by large and destructive waves, is expected near and the
east of where Agatha makes landfall.
2. Life-threatening hurricane-force winds are expected in portions
of the hurricane warning area in Oaxaca, Mexico, starting midday
and continuing through this evening. Tropical storm conditions
have already begun along the coast of Oaxaca and will spread
eastward within the warning area through today and tonight.
3. Heavy rains associated with Agatha will continue over portions of
southern Mexico through Tuesday. This will pose a threat of
potentially life-threatening flash flooding and mudslides.
FORECAST POSITIONS AND MAX WINDS
INIT 30/0900Z 14.8N 97.7W 95 KT 110 MPH
12H 30/1800Z 15.4N 96.8W 95 KT 110 MPH
24H 31/0600Z 16.3N 95.6W 60 KT 70 MPH...INLAND
36H 31/1800Z 16.9N 94.7W 35 KT 40 MPH...INLAND
48H 01/0600Z...DISSIPATED
$$
Forecaster Berg
