000 WTPZ43 KNHC 100242 TCDEP3 Tropical Storm Julia Discussion Number 15 NWS National Hurricane Center Miami FL EP182022 1000 PM CDT Sun Oct 09 2022 Julia's low-level center has not been easy to locate this evening in infrared satellite imagery, but a couple of SSMIS microwave overpasses between 2300-2331 UTC suggest that the center was located very close to the northwestern coast of Nicaragua. A band of deep convection has developed to the southeast of the estimated center but it lacks significant curvature. Assuming some additional weakening occurred before Julia exited the coast, the initial intensity has been reduced to 35 kt which is in line with the latest Dvorak estimate from TAFB. However, there is larger than normal uncertainty regarding Julia's initial intensity. Hopefully, scatterometer data will provide some clarity on the intensity of the cyclone overnight. Since the northern portion of Julia's circulation is forecast to continue interacting with the mountainous terrain of central America, additional weakening is expected over the next 12 to 24 hours. Forecast wind fields from the GFS, ECMWF, and UKMET indicate that the circulation is likely to lose definition over the next 12 to 18 hours, and by 24 hours Julia is forecast to dissipate as it is absorbed within a broad surface trough/low associated with a Gulf of Tehuantepec gap wind event. Julia's appears to be moving between west and west-northwest at about 13 kt. A west-northwestward motion around the southwestern portion of a mid-level ridge over the southeastern Gulf of Mexico should continue until dissipation occurs. The NHC track forecast is again on the northern side of the model envelope, close to the GFS and ECMWF model fields. After 24 hours, the model trackers latch on to the vorticity associated with the broad circulation mentioned above, and not Julia itself. Key Messages: 1. Julia is forecast to move near the coasts of northwestern Nicaragua, Honduras, and El Salvador through Monday, where tropical storm warnings are in effect. Tropical-force-winds are also possible on Monday along the Pacific coast of Guatemala, where a tropical storm watch is in effect. 2. Life-threatening flash flooding and mudslides are expected across portions of Central America into Monday. Flash flooding is anticipated across the Isthmus of Tehuantepec in Mexico early this week. FORECAST POSITIONS AND MAX WINDS INIT 10/0300Z 12.8N 88.1W 35 KT 40 MPH 12H 10/1200Z 13.4N 90.1W 30 KT 35 MPH 24H 11/0000Z...DISSIPATED $$ Forecaster Brown