Tropical Storm Erick Forecast Discussion Number 4
Issued at 900 AM CST Tue Jun 17 2025
472 WTPZ45 KNHC 171445 TCDEP5 Tropical Storm Erick Discussion Number 4 NWS National Hurricane Center Miami FL EP052025 900 AM CST Tue Jun 17 2025 Erick's structure continues to show signs of organization, with a partial 0819 UTC AMSR2 microwave pass possibly showing the initial development of an inner core. Subjective Dvorak estimates from TAFB and SAB are T2.5/35 kt, and the latest objective ADT estimate is just over 40 kt. Based on a blend of these data, the initial intensity is raised to 40 kt. Erick appears to have slowed down a bit and is moving west-northwestward (300 degrees) at 8 kt. The storm is reaching the western extent of a mid-level ridge to the north, with a mid-/upper-level trough located over northern Mexico. These features should cause Erick to turn northwestward later today, with that trajectory continuing for the next 3 days. Speed-wise, the cyclone is likely to move at its slowest (around 6 kt) this evening but then gradually accelerate during the next several days. Although the models are in good agreement on the general track of Erick, the storm's parallel trajectory to the coast of Mexico will play an important role in exactly which areas receive the most significant wind and surge impacts. The updated NHC track forecast has been nudged westward, and generally lies between the HCCA and TVCE consensus aids. The environment appears ideal for rapid strengthening. Vertical shear is expected to be very low, with the cyclone moving over waters of around 29 degrees Celsius and within a moist mid-level environment of around 80 percent relative humidity. As a result of these conditions, Rapid intensification (RI) indices are rather high, particular for the 36- and 48-hour periods. The NHC intensity forecast explicitly shows RI occurring while Erick approaches the coast of southern Mexico, with a 48-hour intensity just below major hurricane strength. Despite this increase in the forecast intensity, there are still a few models (including the normally skillful HCCA aid) that show Erick reaching major hurricane strength, and additional upward adjustments in the forecast could be required later today. KEY MESSAGES: 1. Erick is expected to rapidly intensify before reaching the coast of southern Mexico on Thursday, and a hurricane warning is now in effect for portions of the coast of Oaxaca. A hurricane watch is in effect for portions of the Guerrero coast. 2. Erick will produce heavy rainfall across portions of Central America and Southwest Mexico through this week. Life threatening flooding and mudslides are possible, especially in areas of steep terrain. 3. A dangerous storm surge is expected to produce coastal flooding near and to the east of where the center crosses the coast, in areas of onshore winds. FORECAST POSITIONS AND MAX WINDS INIT 17/1500Z 12.3N 94.1W 40 KT 45 MPH 12H 18/0000Z 12.8N 94.9W 55 KT 65 MPH 24H 18/1200Z 13.6N 96.0W 70 KT 80 MPH 36H 19/0000Z 14.7N 97.2W 90 KT 105 MPH 48H 19/1200Z 16.0N 98.5W 95 KT 110 MPH 60H 20/0000Z 17.5N 100.2W 60 KT 70 MPH...INLAND 72H 20/1200Z 18.8N 102.1W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 21/1200Z...DISSIPATED $$ Forecaster Berg/Mora
