ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM Tropical Storm Lorena Discussion Number 11 NWS National Hurricane Center Miami FL EP152019 900 PM MDT Thu Sep 19 2019 Geostationary satellite data and a recently received SSM/IS overpass suggest that Lorena has gotten a little better organized since the last advisory, with a central dense overcast forming near or over a small mid-level eye seen in the microwave data. However, the various objective and subjective satellite intensity estimates indicate that the cyclone has not yet regained hurricane strength. The initial intensity is thus held at 60 kt. The initial motion is a somewhat uncertain 305/9. Lorena is located between a mid- to upper-level ridge over northern Mexico and Tropical Storm Mario to the south-southwest, while a large mid- to upper-level trough is northwest of Lorena over the western United States and the northeastern Pacific. The potential for Lorena to interact with Mario is producing a large spread in the guidance and a low confidence track forecast. Much of the track guidance, including the GFS, HWRF, HMON, and the GFS ensemble mean show Lorena turning so sharply westward around the north side of Mario that it passes south of the Baja California peninsula. At the other extreme is the older version of the GFS, which forecasts Lorena to moved northwestward up the Gulf of California due mainly to the influence of the Mexican ridge and the U. S. trough. The ECMWF model forecasts a track generally over the Baja California peninsula, while the UKMET shows a track into the southern Gulf of California followed by a westward turn across southern Baja. The new forecast track is similar to the previous track in forecasting Lorena to pass near the southern end of the Baja California peninsula, then move generally northwestward near the west coast of the peninsula. The new track lies well to the right of the various consensus models, but it lies to the left of the ECWMF and the old GFS model. Adjustments to the forecast track may occur once the amount of influence Mario will have on Lorena become more apparent. The intensity forecast is also very uncertain due to the track forecast uncertainties. The new intensity forecast is based on the track forecast that keeps Lorena over the water near the west coast of the the Baja California peninsula, with the cyclone re-gaining hurricane status before it moves over colder sea surface temperatures and eventually dissipates over the cold water. However there are three alternate scenarios. First, the GFS suggests the possibility that Mario will absorb Lorena and cause it to completely dissipate. Second, the older version of the GFS, with its forecast over the warm waters of the Gulf of California, would could allow Lorena to be stronger than currently forecast. Finally, the ECMWF's track over the Baja California Peninsula would also cause Lorena to weaken faster than currently forecast. The forecast track requires new warnings and watches for portions of Baja California del Sur. Additional warnings and watches may be required for this area on Friday. Key Messages: 1. Heavy rainfall will continue over portions of the Mexican states of Michoacan, Colima, and Jalisco during the next day or so. This rainfall may produce life-threatening flash flooding and mudslides. 2. Lorena is forecast to re-strengthen into a hurricane and bring hurricane-force winds and heavy rainfall to a portion of the southern Baja California peninsula beginning on Friday. A Hurricane Warning has been issued, and preparations to protect life and property should be rushed to completion. FORECAST POSITIONS AND MAX WINDS INIT 20/0300Z 22.3N 107.7W 60 KT 70 MPH 12H 20/1200Z 22.6N 108.8W 65 KT 75 MPH 24H 21/0000Z 23.1N 110.2W 70 KT 80 MPH 36H 21/1200Z 23.9N 111.4W 70 KT 80 MPH 48H 22/0000Z 24.8N 112.5W 60 KT 70 MPH 72H 23/0000Z 27.5N 114.8W 35 KT 40 MPH 96H 24/0000Z 29.5N 116.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 25/0000Z...DISSIPATED $$ Forecaster Beven NNNN