000 WTPZ45 KNHC 062048 TCDEP5 HURRICANE JULIO DISCUSSION NUMBER 12 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102014 200 PM PDT WED AUG 06 2014 Satellite imagery shows that Julio has become a little better organized, with multiple convective bands near the center and an eye possibly trying to form. The latest SSM/IS overpass, though, suggests the eyewall is still open to the north. The satellite intensity estimates from TAFB and SAB are 77 kt and 65 kt, so the initial intensity remains at a possibly-conservative 65 kt. The cirrus outflow remains good over the southwestern semicircle and poor elsewhere. The initial motion is now 290/15, which is a little to the right of the previous advisory. The NHC model guidance is in good agreement on Julio moving along the southern periphery of a deep-layer ridge to its north for the next 72 hours or so. After that, a weakness in the ridge is forecast to develop north of the Hawaiian Islands, and Julio is expected to turn more northwestward. Based on current trends, Julio is likely to be a little north of the previous forecast during the first 48 hours or so. However, at the later times the dynamical models have shifted southward since their previous forecasts, with the most notable shift by the GFS. The consensus models and the center of the guidance envelope have also shifted southward at 96-120 hours. The new track forecast will also be adjusted southward at those times, but it lies a little to the north of the consensus models. The NOAA G-IV jet is currently flying a synoptic surveillance mission for Hurricane Iselle, and this data is also expected to help subsequent forecasts of Julio. The dynamical models have come into reasonably good agreement that Julio will remain in a light vertical wind shear environment through the forecast period. Thus, the intensity is most likely going to be controlled by sea surface temperatures and nearby dry air. While Julio is moving over gradually decreasing sea surface temperatures, some additional strengthening is possible during the next 12 hours or so. After that, the cyclone is expected to traverse sea surface temperatures of 25C-26C and gradually move into a drier air mass. This should cause a gradual weakening for the rest of the forecast period. The new intensity forecast is adjusted slightly from the previous forecast and is in best agreement with the intensity consensus. It should be noted that despite the marginal sea surface temperatures and moisture, none of the dynamical models forecast Julio to dissipate during the next 5 days. Indeed, the GFDL and HWRF are stronger than the current forecast at 96-120 hours. FORECAST POSITIONS AND MAX WINDS INIT 06/2100Z 15.8N 131.8W 65 KT 75 MPH 12H 07/0600Z 16.3N 134.2W 70 KT 80 MPH 24H 07/1800Z 16.9N 137.4W 70 KT 80 MPH 36H 08/0600Z 17.4N 140.3W 70 KT 80 MPH 48H 08/1800Z 18.0N 143.3W 65 KT 75 MPH 72H 09/1800Z 19.5N 148.5W 60 KT 70 MPH 96H 10/1800Z 21.5N 154.0W 55 KT 65 MPH 120H 11/1800Z 24.5N 158.5W 50 KT 60 MPH $$ Forecaster Beven