000
WTPZ43 KNHC 090846
TCDEP3
 
Tropical Storm Cosme Discussion Number   4
NWS National Hurricane Center Miami FL       EP032025
200 AM MST Mon Jun 09 2025
 
The satellite presentation of Cosme has continued to gradually 
improve since the previous advisory, with sustained deep convection 
holding over the low-level center. A timely 09/0524Z ASCAT pass 
helped with the initial intensity and 34 kt wind radii estimates, 
with several wind barbs showing 40 to 45 knot winds. The latest 
subjective Dvorak intensity estimates from TAFB and SAB were T3.0/45 
knots and T2.5/35 knots respectively. Meanwhile, the objective 
Dvorak satellite estimates range from 40 to 50 knots. The initial 
intensity has been adjusted up to 45 knots with this advisory 
package, in line with the most recent ASCAT pass.

Cosme is moving toward west-northwest at 8 kt. This general motion 
is expected to continue during the next 24 hours to the south of a 
mid-level ridge, with a gradual slowing in forward speed. Tonight 
and Tuesday Barbara is forecast to erode the mid-level ridge to the 
north of Cosme, resulting in a further slowing in motion and a shift 
to the north. An increase in forward speed and a motion to the 
north-northeast is expected Tuesday night, with Cosme forecast to 
become a post-tropical remnant low on Wednesday. The latest track 
forecast is very close to that of the previous advisory and is 
generally a blend of the consensus guidance.

Environmental conditions continue to look conducive for 
strengthening of Cosme during the next 24 hours or so. Vertical wind 
shear will lighten up some while the system passes over 27/28C water 
with abundant deep layer moisture. The intensity forecast is similar 
to the previous advisory, bringing Cosme close to hurricane strength 
late today or tonight. Beyond 24 hours, vertical wind shear is 
forecast to increase and mid-level moisture is forecast to decrease, 
which should lead to a gradual weakening of Cosme. A more rapid 
weakening is then expected by Wednesday as the system moves over 
much cooler water, with Cosme expected to dissipate by 96 hours.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/0900Z 14.2N 112.8W   45 KT  50 MPH
 12H  09/1800Z 14.6N 113.5W   55 KT  65 MPH
 24H  10/0600Z 15.0N 114.2W   60 KT  70 MPH
 36H  10/1800Z 15.4N 114.2W   55 KT  65 MPH
 48H  11/0600Z 16.5N 113.4W   45 KT  50 MPH
 60H  11/1800Z 17.9N 113.1W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  12/0600Z 19.0N 113.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  13/0600Z...DISSIPATED
 
$$
Forecaster Jelsema/Hagen