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Tropical Storm Mario Discussion Number   9
NWS National Hurricane Center Miami FL       EP132025
200 PM MST Sun Sep 14 2025
 
A large, cold convective burst formed over the center of Mario 
around 13Z this morning and subsequently expanded, and the burst has 
persisted since that time.  A 1657 UTC ASCAT-B pass showed several 
34-38 kt vectors within 30 miles of Mario's center.  The latest 
subjective Dvorak estimates are 3.0/45 kt from TAFB and 2.0/30 kt 
from SAB, while recent UW-CIMSS objective intensity estimates are in 
the 40-45 kt range.  Winds at Socorro Island, located less than 30 n 
mi west-southwest of the center, are up to 20 kt gusting to 29 kt, 
with a 1006 mb pressure.  The initial intensity is increased to 40 
kt for this advisory.
 
The aforementioned ASCAT pass and surface observations from Socorro 
Island have been helpful at estimating the initial position of 
Mario, which is slightly to the east of the previous NHC forecast.  
The current motion of the cyclone is estimated to be slowly toward 
the west-northwest at 300/6 kt. This general motion should continue 
for the next few days as Mario is primarily steered by deep-layer 
ridging centered over Mexico.  The GFS and Google DeepMind models 
are on the right, or north side of the guidance envelope, whereas 
the ECMWF and HCCA lie on the left or southern side of the guidance. 
 The latest NHC forecast is adjusted slightly to the right, or east, 
of the previous official forecast, fairly close to a blend of the 
latest HCCA and TVCE models.

Mario will continue to be in a favorable environment for 
strengthening for another 24-30 hours, with low shear under 10 kt, 
warm sea-surface temperatures, and plenty of mid-level moisture.  By 
hour 30, the sea-surface temperatures will be below 27C and then 
below 26C by hour 36.  Around the same time, southwesterly shear 
will begin increasing while the mid-level moisture and instability 
plummet.  These conditions favor the commencement of weakening on 
Monday night.  All model guidance, including the latest hi-res 
hurricane models, do not show more than about 10 kt of additional 
strengthening.  In fact, the latest intensity forecast is at the 
high end of the model guidance envelope through 24 h.  Given the 
favorable environment for the next 24 h, a higher peak intensity in 
the 55-60 kt range should not be ruled out.  By 36 h, the NHC 
forecast is similar to the previous one, which is closer to the 
middle of the guidance envelope.  The cyclone should become a 
remnant low in 48-60 h and dissipate just beyond 72 h.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  14/2100Z 18.9N 110.7W   40 KT  45 MPH
 12H  15/0600Z 19.6N 111.9W   45 KT  50 MPH
 24H  15/1800Z 20.4N 113.9W   50 KT  60 MPH
 36H  16/0600Z 21.5N 115.9W   45 KT  50 MPH
 48H  16/1800Z 22.8N 117.9W   35 KT  40 MPH
 60H  17/0600Z 24.0N 119.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  17/1800Z 24.9N 121.2W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  18/1800Z...DISSIPATED
 
$$
Forecaster Hagen
 
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