ZCZC MIATCDEP3 ALL TTAA00 KNHC DDHHMM TROPICAL STORM CARLOS DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032015 1000 AM CDT THU JUN 11 2015 The organization of the tropical cyclone has gradually increased, with a curved band of deep convection wrapping more than half way around the system's center. The intensity is analyzed to be 35 kt based upon a blend of TAFB, SAB, and ADT Dvorak estimates with consideration that the pattern recognition methods were apparently a bit biased high in comparison with the ASCAT scatterometer winds overnight. Thus the system is upgraded to Carlos, the third tropical storm of the season in the Eastern North Pacific. Even though the cyclone is over very warm waters, Carlos is likely to continue to intensify at a moderate pace due to about 15 kt of northeasterly vertical shear expected during the next two to three days. At the longer forecast times, the shear may decrease as Carlos approaches the axis of the upper-tropospheric ridge. However, a dry and more stable environment at that time may preclude substantial intensification. Given that Carlos' track now is projected to remain away from the Mexican coast for at least the short-term, it is less likely that land influences will affect the system. The official intensity forecast is based upon a blend of the LGEM and SHIPS statistical-dynamical models and is slightly lower than that from the previous advisory. Carlos is moving toward the northwest at about 5 kt. Shortly, a developing trough over the Gulf of Mexico will cause the steering pattern to weaken and Carlos should meander northward for the next couple of days. In three to four days, a deep-layered ridge will become re-established north of Carlos and help propel it northwest or west-northwestward at a slow forward speed, paralleling the southwestern Mexican coast. The official track prediction is based upon the TVCN multi-model track consensus and is just slightly southwest of that from the previous advisory. FORECAST POSITIONS AND MAX WINDS INIT 11/1500Z 13.6N 100.4W 35 KT 40 MPH 12H 12/0000Z 14.0N 100.7W 45 KT 50 MPH 24H 12/1200Z 14.2N 100.8W 50 KT 60 MPH 36H 13/0000Z 14.4N 100.7W 60 KT 70 MPH 48H 13/1200Z 14.7N 100.7W 65 KT 75 MPH 72H 14/1200Z 15.6N 101.7W 70 KT 80 MPH 96H 15/1200Z 16.8N 104.1W 70 KT 80 MPH 120H 16/1200Z 17.7N 106.4W 75 KT 85 MPH $$ Forecaster Landsea NNNN