264 WTPZ45 KNHC 250835 TCDEP5 Tropical Storm Juliette Discussion Number 3 NWS National Hurricane Center Miami FL EP102025 200 AM MST Mon Aug 25 2025 Since the time of the previous NHC advisory, the sheared convective burst associated with the tropical cyclone has grown larger, with a large area of cloud tops colder than -80C on GOES-West infrared imagery. Furthermore, the low level center, which had been exposed to the east of the burst, appears to have moved underneath the eastern edge of the convection. This suggests the moderate northeasterly vertical wind shear is weakening. The UW-CIMSS objective intensity estimates have been steadily increasing, and are now in the 32-35 kt range. TAFB provided a subjective Dvorak estimate of 35 kt, and an ASCAT pass from 25/0441 UTC showed a few 35 kt vectors in the deep convection that might have been a bit rain-inflated. Regardless of the accuracy of the ASCAT data, given the improving satellite presentation and persistence of the large, cold convective mass, the depression is upgraded to Tropical Storm Juliette with a 35-kt intensity. Juliette is moving west-northwestward, or 290/11 kt on the south side of a subtropical high. This general motion is expected to continue during the next day or so. After that time, a gradual turn to the northwest is forecast as the system is influenced by a weakness in the subtropical ridge. The model guidance has shifted to the left and a bit faster compared to the previous cycle, and so has the NHC forecast. The latest official forecast is in best agreement with the HFIP corrected consensus (HCCA) model. Spread in the model guidance increases by day 3, and the NHC forecast shows the cyclone slowing down at that time, similar to consensus aids. Environmental conditions appear favorable for Juliette to strengthen for at least 36-42 more hours. The 10-kt northeasterly vertical shear being experienced by the cyclone should diminish to single digits later today, while the system traverses warm ocean waters. By 48 h, Juliette should reach colder waters and a more stable atmosphere, and these conditions will induce weakening. The latest NHC intensity forecast is slightly higher than the previous one and lies at the high end of the model guidance at 36-48 h. The reason for this is that with the shift in the forecast track to the left, Juliette should have a few additional hours to strengthen before it reaches the less favorable conditions. With the decreasing shear later today, there should be enough time for Juliette to become a high-end tropical storm. FORECAST POSITIONS AND MAX WINDS INIT 25/0900Z 16.8N 111.8W 35 KT 40 MPH 12H 25/1800Z 17.5N 113.5W 40 KT 45 MPH 24H 26/0600Z 18.4N 115.5W 45 KT 50 MPH 36H 26/1800Z 19.4N 117.3W 55 KT 65 MPH 48H 27/0600Z 20.6N 118.9W 55 KT 65 MPH 60H 27/1800Z 21.9N 120.2W 45 KT 50 MPH 72H 28/0600Z 23.2N 121.1W 35 KT 40 MPH 96H 29/0600Z 25.0N 122.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 30/0600Z 25.9N 122.9W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Hagen
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