000
WTPZ43 KNHC 011441
TCDEP3
 
Tropical Storm Marie Discussion Number   2
NWS National Hurricane Center Miami FL       EP132026
800 AM MST Tue Sep 01 2026
 
This morning's GOES-18 Proxy-VIS satellite imagery indicates that
Marie is gradually becoming better organized.  Deep convection with 
cold cloud tops of -81C is developing over the surface circulation 
center, and a spiral band is wrapping around the center from the 
southwest part of the cyclone.  No changes yet in both the 
subjective and objective satellite intensity guidance, however, so 
the initial intensity is held at 40 kt for this advisory.
 
The ocean is warm, the low- to mid-levels of the atmosphere are
moist, and the deep-layer shear is low.  Subsequently, strengthening
is expected, and Marie should become a hurricane by Wednesday 
night.  By the weekend, the GFS/ECMWF SHIPS statistical intensity 
guidance and the physics-based deterministic models indicate that 
Marie will encounter a drier, stable marine layer air mass while 
traversing progressively cooler oceanic temperatures.  Accordingly, 
the NHC intensity forecast follows suit and shows Marie slowly 
weakening beyond day 4.
 
An earlier 0707 UTC OSCAT-3 scatterometer overpass and a
fortuitous 1247 UTC GPM/GMI image indicated that the surface center 
was a bit farther northeast than previously noted, and near 
the northwestern edge of the deep convective canopy.  Marie's 
initial motion is estimated to be northwestward, or 315/8 kt.  A 
mid-tropospheric subtropical ridge stretching from northern
Mexico westward over the extreme eastern Pacific should steer
the cyclone generally northwestward through Thursday.  
Afterward, the subtropical high should weaken in response to an 
amplifying mid- to upper-level trough approaching the west coast of 
the U.S. This change in the large-scale synoptic pattern is 
expected to slow Marie's forward speed.  For the remainder of the 
forecast, the aforementioned mid- to upper-level trough should fill 
and lift northeastward, allowing the ridge to build and reestablish 
north of Marie and steer the system back toward the west-northwest 
through the weekend.  There's still quite a bit of cross-track 
spread in the model suite beyond day 3, with one cluster indicating 
a north-northwestward motion while another model cluster shows a 
more west-northwestward trajectory.  The official forecast reflects 
slight adjustments to the left of the previous forecast and favors 
a blend of the skilled NOAA HCCA consensus aid and the Google 
DeepMind FNv3 ensemble mean forecast.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  01/1500Z 15.0N 108.7W   40 KT  45 MPH
 12H  02/0000Z 16.0N 109.8W   50 KT  60 MPH
 24H  02/1200Z 17.1N 111.2W   60 KT  70 MPH
 36H  03/0000Z 18.0N 112.4W   70 KT  80 MPH
 48H  03/1200Z 19.0N 113.9W   80 KT  90 MPH
 60H  04/0000Z 19.7N 115.6W   85 KT 100 MPH
 72H  04/1200Z 20.3N 117.0W   85 KT 100 MPH
 96H  05/1200Z 21.4N 119.8W   80 KT  90 MPH
120H  06/1200Z 22.3N 122.0W   75 KT  85 MPH
 
$$
Forecaster Roberts