ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM TROPICAL STORM FAUSTO DISCUSSION NUMBER 2 NWS NATIONAL HURRICANE CENTER MIAMI FL EP062014 800 PM PDT MON JUL 07 2014 The convective cloud pattern associated with Tropical Storm Fausto has continued to improve with numerous small curved bands having developed in the northern semicircle, while a large curved band has persisted in the southern semicircle. The upper-level outflow is good to excellent, and it has continued to expand and become more symmetrical. The initial intensity has been increased to 40 kt based on the improved cloud pattern, a 1757 UTC ASCAT-B overpass that showed a peak surface wind of 38 kt in the southeastern quadrant, and also the most recent UW-CIMSS ADT satellite intensity estimates of T2.8/41 kt. The initial motion estimate is 275/10 kt. The forecast track was shifted to the right of the previous advisory track, but the forecast reasoning remains unchanged. Fausto should move westward to west-northwestward for the next 72 hours or so as the cyclone skirts the southern periphery of a deep-layer ridge located to its north along 24N-25N latitude. By Days 4 and 5, a mid-tropospheric trough is forecast to dig southward from the north-central Pacific and weaken the ridge between 140W-150W longitude, causing Fausto to turn more northwestward toward the weakness or break in the ridge. As the cyclone gains latitude, it is expected to encounter increasing westerly to southwesterly vertical wind shear and cooler waters by Days 4 and 5, which should weaken the system and cause it to become more shallow and be steered more westward by the strong low-level easterly trade wind flow. The official forecast track is south of the consensus model TCVE due to expected weak northwesterly mid-level wind shear impinging on the vortex column and keeping it farther south closer to the deep convection. This complex steering pattern is depicted well by the HWRF model, which initialized Fausto much better than the other models, and shows a deeper vortex throughout the forecast period. Fausto is expected to remain in a favorable environment of wind shear less than 10 kt, mid-level moisture greater than 70 percent, and sea-surface temperatures in excess of 28C for the next 48 hours or so, which should result in at least gradual strengthening. The HWRF model makes Fausto a hurricane in about 48 hours, which isn't entirely out of the question if convection can wrap around the north side of the low-level center, resulting in a stronger and better developed vortex column. For now, however, the official intensity forecast remains similar to the previous advisory and closely follows the intensity consensus model IVCN due to modest mid-level shear undercutting the favorable upper-level outflow pattern, which is expected to inhibit development somewhat. FORECAST POSITIONS AND MAX WINDS INIT 08/0300Z 9.6N 120.7W 40 KT 45 MPH 12H 08/1200Z 9.9N 122.2W 45 KT 50 MPH 24H 09/0000Z 10.5N 124.6W 50 KT 60 MPH 36H 09/1200Z 11.2N 127.2W 55 KT 65 MPH 48H 10/0000Z 12.1N 129.8W 55 KT 65 MPH 72H 11/0000Z 13.8N 135.0W 55 KT 65 MPH 96H 12/0000Z 15.5N 139.4W 45 KT 50 MPH 120H 13/0000Z 16.8N 143.5W 35 KT 40 MPH $$ Forecaster Stewart NNNN