ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM
 
Potential Tropical Cyclone Four-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP042025
300 PM CST Thu Jun 12 2025
 
Showers and thunderstorms associated with an area of low pressure
located south of Mexico, that the National Hurricane Center has been
monitoring have increased and are showing signs of organization.
While some mid-level rotation is evident in visible satellite images
near the northeast edge of ongoing convection, the low-level
circulation remains broad and elongated. However, the system is
expected to become a tropical storm tonight or tomorrow, and it is
possible that it will bring tropical storm conditions to land areas
within the next 36 to 48 hours. Therefore, the National Hurricane
Center is initiating Potential Tropical Cyclone advisories for this
disturbance.
 
The initial motion is more uncertain than normal since the system is 
still in the formative stage, but the best estimate is 
west-northwestward at about 6 kt. A northwestward to 
west-northwestward motion is anticipated during the next few days as 
the system moves parallel to the coast of southwestern Mexico, being 
steered by a mid-level ridge. Model guidance is in fairly good 
agreement with the overall track evolution, although minor track 
shifts may cause greater impacts to the coast of Mexico. The NHC 
forecast lies near the simple consensus aids. Since the disturbance 
currently lacks a well-defined center, users are reminded that the 
track forecast uncertainty is typically larger in these situations, 
and future track adjustments may be required.
 
The models suggest a more well-defined center should develop 
overnight or tomorrow. Once the system becomes better organized and 
develops an inner core, the environmental conditions appear 
favorable for strengthening during the next couple of days, with 
warm sea surface temperatures and abundant moisture. However, the 
system will be dealing with some easterly to northeasterly wind 
shear. The NHC forecast shows steady strengthening over the next few 
days, although there are some guidance aids such as HCCA and the 
hurricane regional models that lie above the current NHC forecast. 
Given some uncertainty in how quickly the system consolidates and 
the limiting wind shear, the NHC forecast lies near the simple 
intensity consensus aids. Beyond day 4, environmental conditions 
will become hostile which should lead to weakening, and the system 
should struggle to produce convection moving into cooler SSTs and a 
more stable air mass. The current NHC forecast has the system 
becoming a remnant low at that time, and calls for dissipation by 
day 5.
 
Based on the NHC forecast, Tropical Storm Watches have been issued
for portions of southwestern Mexico.
 
KEY MESSAGES:
 
1. The outer bands of Potential Tropical Cyclone Four-E may bring 
locally heavy rainfall to the Mexican states of Guerrero, Michoacan, 
and Colima through this weekend. Isolated flooding and mudslides, 
especially in areas of steep terrain, are possible.
 
2. The disturbance is forecast to be at tropical storm strength when 
it moves near the southwestern coast of Mexico on Saturday. Tropical 
storm conditions are possible over portions of that area.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  12/2100Z 11.3N 100.2W   30 KT  35 MPH...POTENTIAL TROP CYCLONE
 12H  13/0600Z 12.0N 100.4W   35 KT  40 MPH...TROPICAL CYCLONE
 24H  13/1800Z 13.3N 101.3W   45 KT  50 MPH
 36H  14/0600Z 14.3N 102.7W   55 KT  65 MPH
 48H  14/1800Z 15.5N 104.3W   60 KT  70 MPH
 60H  15/0600Z 16.5N 106.2W   60 KT  70 MPH
 72H  15/1800Z 17.1N 108.2W   50 KT  60 MPH
 96H  16/1800Z 17.3N 112.2W   30 KT  35 MPH...POST-TROPICAL
120H  17/1800Z...DISSIPATED
 
$$
Forecaster Kelly
 
NNNN