Tropical Depression Fifteen-E Forecast Discussion
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280 WTPZ45 KNHC 150234 TCDEP5 Tropical Depression Fifteen-E Discussion Number 6 NWS National Hurricane Center Miami FL EP152026 800 PM PDT Mon Sep 14 2026 Visible satellite imagery continues to show the exposed center of Tropical Depression Fifteen-E well to the west of the convective area, due to westerly vertical wind shear of 10 to 15 kt affecting the system. In fact, the center has ran out farther ahead to the west of the convection compared to earlier today, now about 40-45 n mi from the nearest deep convection. The latest subjective and objective satellite intensity estimates range from 29-35 kt. An earlier ASCAT-B overpass at 14/1630 UTC showed peak vectors of 27 kt located 60 to 80 n mi from the center in the eastern semicircle. The initial intensity is held at 30 kt since the tropical cyclone has not become any better organized since the time of the ASCAT pass. Satellite fixes over the past 12 to 18 hours have been a bit erratic, but generally indicate a motion slightly south of due west, or 260 degrees at 9 knots. Ridging to the northwest of the depression should keep it on a similar heading for the next couple of days. By late Wednesday, global models show the orientation of the ridge changing slightly, which should cause the depression to turn to a direction between west and west-northwest with a slight increase in forward speed for the remainder of the forecast period. The latest NHC track forecast is a bit south of the previous one, and lies between the farther north TVCN and the farther south HCCA and GDMI. It should be noted that the cross track spread is quite large from hour 24 onward, and confidence in the track forecast is below average. The environment is generally unfavorable for significant strengthening due to the moderate northwesterly vertical wind shear advecting some dry air into the center of the depression. Even though this shear should decrease some over the next 24 h, the intensity models are in good agreement that this system is unlikely to strengthen beyond a low-end tropical storm. Given how far any convection is from the center currently, and that the system should start weakening in a couple of days as it reaches a drier environment, significant intensification appears unlikely. The depression could potentially become post-tropical or dissipate sooner than this forecast indicates. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 16.5N 121.6W 30 KT 35 MPH 12H 15/1200Z 16.3N 122.9W 30 KT 35 MPH 24H 16/0000Z 16.2N 124.7W 35 KT 40 MPH 36H 16/1200Z 16.1N 126.6W 35 KT 40 MPH 48H 17/0000Z 16.1N 128.8W 35 KT 40 MPH 60H 17/1200Z 16.3N 131.1W 30 KT 35 MPH 72H 18/0000Z 16.6N 133.6W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 19/0000Z 17.2N 138.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 20/0000Z...DISSIPATED $$ Forecaster Hagen