000 WTPZ42 KNHC 260239 TCDEP2 HURRICANE SANDRA DISCUSSION NUMBER 10 NWS NATIONAL HURRICANE CENTER MIAMI FL EP222015 800 PM MST WED NOV 25 2015 The intensification of Sandra seems to have slowed during the past few hours. The cloud tops in the eyewall have continued to cool with temperatures now colder than -80C. However, as this has occurred the eye has become less distinct. Satellite intensity estimates are 115 kt from SAB and 102 kt from TAFB, and there is a recent CIMSS ADT estimate of 110 kt. A blend of these data is used for the initial intensity of 105 kt. The initial motion is now 320/7. Sandra is moving around the western end of a mid- to upper-level ridge over southern Mexico, and during the next 96 hours it should move into southwesterly flow between the ridge and a deep-layer trough over the western United States. While the guidance is generally in good agreement with this scenario, there remains some spread between the slower and farther west ECMWF and the faster and farther east GFS. As seen in the previous advisory, this is due to the GFS keeping Sandra a stronger system than does the ECMWF. The new track forecast is more or less an update of the previous forecast, but remains slower than the model consensus in deference to the ECMWF, whose weaker forecast again looks more realistic at this time. The new forecast has the center of Sandra passing near the southern end of the Baja California peninsula between 48-72 hours and subsequently moving into mainland Mexico between 72-96 hours. Some additional strengthening is possible tonight. After that, Sandra is expected to encounter rapidly increasing southwesterly vertical wind shear, which should cause rapid weakening as the center approaches Baja California and mainland Mexico. The new intensity forecast is near the intensity consensus IVCN through 48 hours, and then it is a little stronger than the guidance at 72 hours. After Sandra makes landfall in Mexico, it is forecast to dissipate quickly over the mountains. Although Sandra is forecast to weaken, it is still too soon to know exactly how it will affect portions of the southern Baja California peninsula or the west coast of mainland Mexico. Watches will not be required on this advisory. However, interests in those areas should continue to monitor the progress of Sandra. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 13.6N 110.4W 105 KT 120 MPH 12H 26/1200Z 14.9N 110.9W 110 KT 125 MPH 24H 27/0000Z 16.7N 111.2W 100 KT 115 MPH 36H 27/1200Z 18.5N 110.9W 85 KT 100 MPH 48H 28/0000Z 20.4N 110.3W 70 KT 80 MPH 72H 29/0000Z 24.0N 108.5W 35 KT 40 MPH 96H 30/0000Z 28.0N 107.0W 20 KT 25 MPH...POST-TROP/INLAND 120H 01/0000Z...DISSIPATED $$ Forecaster Beven