Tropical Cyclone Discussion
330 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