792 WTPZ45 KNHC 222057 TCDEP5 Tropical Depression Ten-E Discussion Number 1 NWS National Hurricane Center Miami FL EP102024 300 PM CST Sun Sep 22 2024 Convection has gradually become better organized today in association with an area of low pressure that the NHC has been monitoring off the coast of southern Mexico. A recent scatterometer pass shows the circulation is closed, with a well-defined center and peak winds of about 30 kt over the southern semicircle. Therefore, a new tropical depression has formed in the eastern Pacific basin. The depression is nearly stationary, but a slow northeastward drift is expected to begin later tonight. The track forecast is challenging, as there is a large spread in the guidance regarding the potential path of the system. Much of the track guidance shows the system moving generally east-northeastward as it becomes captured within the broader circulation of a developing Central American Gyre. However, a couple of global models (ECMWF and UKMET) instead show a northward drift over the next couple of days. The NHC track forecast favors the first scenario, and generally lies between the simple and corrected consensus aids. However, this track forecast is of low confidence given the large spread in the models, and adjustments will likely be required with future issuances. The moist, unstable environment and very warm waters should be conducive for some strengthening of the system during the next couple of days. The NHC intensity forecast lies between the IVCN and HCCA aids, but it should be noted that there are some models indicating the system could reach hurricane strength. While this is not explicitly forecast, it certainly cannot be ruled out given the environmental and oceanic conditions, and interests along the coast of southern Mexico should monitor the latest forecast updates. The peak intensity of the system will be highly dependent on how long the cyclone remains over water before reaching the coast, which is quite uncertain given the track challenges described above. Based on this forecast, the government of Mexico has issued a Tropical Storm Watch for the southern coast of Mexico from Punta Maldonado to Salina Cruz. KEY MESSAGES: 1. Slow-moving Tropical Depression Ten-E will bring very heavy rainfall to coastal portions of southern and southwestern Mexico through the upcoming week. This heavy rainfall will bring a risk of significant flash flooding and mudslides to the Mexican States of Chiapas and Oaxaca, particularly in areas near the coast. 2. The depression is forecast to become a tropical storm while moving near the coast of southern Mexico on Monday or Tuesday. A Tropical Storm Watch has been issued for a portion of the coastline, where tropical storm conditions could begin on Tuesday. 3. The system could strengthen more than forecast if it remains over water. Interests along the coast of southern Mexico should monitor the latest forecast updates, as a Hurricane Watch could be required for a portion of the coastline later tonight or on Monday. FORECAST POSITIONS AND MAX WINDS INIT 22/2100Z 13.8N 98.7W 30 KT 35 MPH 12H 23/0600Z 14.0N 98.6W 35 KT 40 MPH 24H 23/1800Z 14.4N 98.2W 45 KT 50 MPH 36H 24/0600Z 14.8N 97.5W 50 KT 60 MPH 48H 24/1800Z 15.0N 96.6W 55 KT 65 MPH 60H 25/0600Z 15.3N 95.6W 55 KT 65 MPH 72H 25/1800Z 16.1N 94.1W 55 KT 65 MPH 96H 26/1800Z 17.1N 92.9W 20 KT 25 MPH...INLAND 120H 27/1800Z...DISSIPATED $$ Forecaster Reinhart
Tropical Depression Ten-E Forecast Discussion
22
Sep