658
WTPZ43 KNHC 010840
TCDEP3

Tropical Storm Marie Discussion Number   1
NWS National Hurricane Center Miami FL       EP132026
200 AM MST Tue Sep 01 2026

Satellite imagery indicates that the deep convection associated with
the disturbance offshore of southwestern Mexico has become better
organized over the past several hours. A 0327 UTC ASCAT-B pass
showed a well-defined circulation and peak winds of around 40 kt in
the southeastern quadrant. The scatterometer data also indicated
that the tropical-storm-force wind field is confined primarily to
the southern semicircle of the circulation. A subjective Dvorak
classification from TAFB was T2.5/35 kt. Based on these data,
advisories are being initiated on Tropical Storm Marie with an
initial intensity of 40 kt.

Marie is moving northwestward, or 315/8 kt. The subtropical ridge
extending westward from northern Mexico should steer Marie
northwestward during the next several days. The ridge is forecast to
gradually weaken as a broad upper-level trough deepens along the
U.S. West Coast, which should also result in some decrease in the
cyclone`s forward speed. By days 4 and 5, the upper trough is
forecast to begin filling while the mid- to upper-level ridge builds
to the north of Marie, causing the cyclone to gradually turn toward
the west-northwest. The track guidance remains tightly clustered
through about day 3, but there is increasing cross-track spread
thereafter, with some models maintaining a more northward trajectory
and others showing a sharper west-northwestward turn. The NHC track
forecast favors the west-northwestward turn shown by the multi-model
consensus (HCCA) and the Google DeepMind ensemble mean, but
confidence is lower near the end of the forecast period due to the
increasing guidance spread.

Environmental conditions appear favorable for Marie to steadily
strengthen during the next few days. The cyclone is forecast to
remain over warm waters and within an environment of low vertical
wind shear and sufficient mid-level moisture. These conditions
should allow Marie to become a hurricane in a couple of days, with
additional strengthening forecast thereafter. By days 4 and 5,
however, Marie is forecast to encounter a progressively drier
environment while moving over gradually decreasing sea surface
temperatures. These less favorable conditions should bring an end to
the strengthening trend and result in gradual weakening by the end
of the forecast period. The NHC intensity forecast shows Marie
reaching a peak intensity of around 80 kt in about 3 days, and lies
near the middle of the intensity guidance envelope.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0900Z 13.8N 108.9W   40 KT  45 MPH
 12H  01/1800Z 14.8N 109.9W   50 KT  60 MPH
 24H  02/0600Z 16.0N 111.3W   60 KT  70 MPH
 36H  02/1800Z 17.0N 112.5W   70 KT  80 MPH
 48H  03/0600Z 18.0N 114.0W   75 KT  85 MPH
 60H  03/1800Z 18.8N 115.5W   80 KT  90 MPH
 72H  04/0600Z 19.4N 117.0W   80 KT  90 MPH
 96H  05/0600Z 20.9N 119.6W   80 KT  90 MPH
120H  06/0600Z 22.1N 122.1W   70 KT  80 MPH

$$
Forecaster Gibbs