000 WTPZ45 KNHC 070843 TCDEP5 HURRICANE JULIO DISCUSSION NUMBER 14 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102014 200 AM PDT THU AUG 07 2014 Julio's signature in infrared satellite imagery has improved since the last advisory. The hurricane is compact and symmetric, and the eye has cleared out during the past few hours. Satellite intensity estimates have all increased and are now T5.0/90 kt from TAFB, T4.5/77 kt from SAB, and T5.2/95 kt from the UW-CIMSS ADT. A blend of these data supports increasing the winds to 85 kt on this advisory. The forward speed has increased a bit to 290/15 kt. Julio is expected to remain south of the subtropical ridge for the next few days, which will keep it on a westward to west-northwestward trajectory. Global model fields are now indicating that a break in the ridge currently to the north of Hawaii may fill in just enough over the next few days to keep Julio from turning northwestward at the end of the forecast period. The track guidance is tightly clustered for the first 48 hours. After that time, the ECMWF model is a noticeable outlier compared to the rest of the models, showing Julio taking a more northern route as it is steered around a more strongly depicted mid-level high northeast of Hawaii. The updated NHC forecast is largely unchanged from the previous one and lies just to the northeast of the multi-model consensus TVCE after 72 hours. Julio is essentially straddling the 26C sea surface temperature isotherm and is expected to move over water between 25-26C during the next 3 days or so. Even though water temperatures are marginal for strengthening, Julio has a few other factors going for it. Vertical shear is expected to remain light for another 2 days, and Julio appears to be embedded within a much larger moisture envelope than Iselle has had to work with. In addition, Julio's fast motion may help to mitigate the negative influence of upper-ocean mixing of cooler waters. Therefore, the NHC intensity forecast allows for the possibility of further strengthening during the next 12 hours or so and keeps Julio at hurricane strength for the next 2-3 days. Only gradual weakening is anticipated at the end of the forecast period since Julio will be moving over increasingly warmer waters to the north and west of Hawaii. FORECAST POSITIONS AND MAX WINDS INIT 07/0900Z 16.8N 134.9W 85 KT 100 MPH 12H 07/1800Z 17.2N 137.2W 90 KT 105 MPH 24H 08/0600Z 17.7N 140.3W 85 KT 100 MPH 36H 08/1800Z 18.3N 143.2W 80 KT 90 MPH 48H 09/0600Z 19.0N 146.1W 75 KT 85 MPH 72H 10/0600Z 21.0N 151.5W 60 KT 70 MPH 96H 11/0600Z 23.5N 156.5W 55 KT 65 MPH 120H 12/0600Z 25.0N 161.0W 50 KT 60 MPH $$ Forecaster Berg