Issued at 200 PM MST Thu May 29 2025
808 WTPZ41 KNHC 292033 TCDEP1 Tropical Storm Alvin Discussion Number 5 NWS National Hurricane Center Miami FL EP012025 200 PM MST Thu May 29 2025 Satellite imagery depicts that Alvin has continued to become better organized throughout the day, showing convective banding and a central dense overcast with cold cloud tops near -75C located over the low-level center. An earlier scatterometer pass shows wind speeds around 45 kt. Given the improving convective structure since that pass, and increasing objective satellite intensity estimates, the initial intensity has increased to 50 kt for this advisory. The initial motion is 320/10 kt. The storm is expected to continue moving toward the northwest today, then begin turning toward the north-northwest tomorrow as it moves around a ridge centered over central Mexico. By tomorrow night, Alvin will begin moving northward as it is influenced by a mid-level cut-off low. The NHC track forecast is very near the previous one. The storm will remain within a favorable environment of warm sea surface temperatures and low wind shear over the next 12 hours or so. Given the latest convective trends and conducive conditions, the peak intensity forecast has increased this cycle to 60 kt. Tomorrow, Alvin will begin to move into a hostile environment with cooler SSTs, higher wind shear, and a drier mid-level airmass which will induce weakening. Latest model derived IR imagery from both the ECMWF and GFS depict the system becoming devoid of convection, and the latest NHC forecast depicts the system becoming a remnant low in 48 h. Thus, there is high confidence that the system will weaken to a remnant low before it nears the Baja California Peninsula. FORECAST POSITIONS AND MAX WINDS INIT 29/2100Z 15.1N 107.2W 50 KT 60 MPH 12H 30/0600Z 16.0N 108.0W 60 KT 70 MPH 24H 30/1800Z 17.6N 108.7W 50 KT 60 MPH 36H 31/0600Z 19.1N 109.0W 40 KT 45 MPH 48H 31/1800Z 20.5N 109.1W 35 KT 40 MPH...POST-TROPICAL 60H 01/0600Z 22.0N 109.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 01/1800Z...DISSIPATED $$ Forecaster Kelly/Mora