792 WTPZ42 KNHC 060250 TCDEP2 Tropical Storm John Discussion Number 2 NWS National Hurricane Center Miami FL EP122018 900 PM MDT Sun Aug 05 2018 Convection associated with Tropical Depression Twelve-E has continued to become better organized, although recent microwave satellite data suggest the low-level center is elongated from northwest to southeast. Satellite intensity estimates from TAFB and SAB have increased to 35 kt, and based on these the depression is upgraded to Tropical Storm John. The initial motion is 315/7. A westward-moving mid- to upper-level trough over northern Mexico has weakened the subtropical ridge over the northeastern Pacific, and the large-scale models are in good agreement that John will move northwestward at an increasing forward speed toward this weakness. A complicating factor is that John may interact with Tropical Storm Ileana to the east. However, John is much larger than Ileana, and the most likely impact of this interaction is that John could move a little slower than currently forecast. The new forecast track is a little to the north of the previous track after 48 h, but is otherwise similar to the previous forecast. The new track also lies just south of the cluster of consensus models. John is expected to be in an environment of very warm SSTs, low shear, and a moist atmosphere through about 60 h. This environment is quite favorable for rapid intensification (RI), as indicated by high probabilities in the SHIPS RI index, and it is likely that RI will begin as soon as the inner core of the storm becomes better organized. The NHC forecast calls for the storm to become a hurricane in 24-36 h and to reach a peak intensity of 95 kt in about three days. After that, the forecast track takes John over rapidly cooling sea surface temperatures, which should cause at least a steady weakening. The intensity forecast is in best agreement with the intensity consensus. It should be noted, however, that the SHIPS and LGEM models both show more intensification than the official forecast and make John a major hurricane in about three days. FORECAST POSITIONS AND MAX WINDS INIT 06/0300Z 14.9N 106.2W 35 KT 40 MPH 12H 06/1200Z 15.6N 107.0W 45 KT 50 MPH 24H 07/0000Z 16.3N 107.9W 60 KT 70 MPH 36H 07/1200Z 17.3N 108.9W 75 KT 85 MPH 48H 08/0000Z 18.5N 110.3W 90 KT 105 MPH 72H 09/0000Z 21.5N 113.5W 95 KT 110 MPH 96H 10/0000Z 24.0N 118.0W 65 KT 75 MPH 120H 11/0000Z 26.0N 122.0W 40 KT 45 MPH $$ Forecaster Beven