ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM Hurricane Barbara Discussion Number 7 NWS National Hurricane Center Miami FL EP022019 800 PM PDT Mon Jul 01 2019 Passive microwave imagery over the past 6 hours indicates that the inner-core convection of Barbara has continued to consolidate and a ragged low- to mid-level eye has formed. However, a pronounced dry intrusion has periodically worked its way into the center of the convective cloud mass, resulting in brief erosions of the eyewall. Despite the dry air, bursts of deep convection have been developing near the center and the most recent hi-resolution GOES-17 visible satellite images suggest that a more robust eyewall is possibly developing. Dvorak satellite intensity estimates are T4.5/77 kt from TAFB and SAB, and UW-CIMSS ADT and SATCON values are T4.5/77 kt and 80 kt, respectively. Given the occasional appearance of a ragged cloud-filled eye in visible satellite imagery, the initial intensity has been increased to 85 kt for this advisory, meaning that Barbara has rapidly intensified during the past 24 hours. Barbara's initial motion is 280/13 kt. There remains no significant change to the previous track forecast rationale. Barbara should turn toward the west-northwest shortly, and that general motion is forecast to continue for the next 36-48 hours. After that time, a passing shortwave trough is expected to weaken the ridge to the north of the hurricane, allowing Barbara to move more poleward. In the 96-120 hour period, however, the ridge is forecast to build back in, forcing Barbara back toward the west. The new NHC track forecast is very similar to the previous advisory track, and lies close to a blend of the TVCN, HCCA, and FSSE consensus models. The combination of low vertical wind shear, an expanding upper-level outflow regime, a moist mid-level environment, and SSTs greater than 28 deg C is expected to persist for at least the next 36 hours, allowing Barbara to continue to rapidly strengthen during that time. By 48 hours, however, steady weakening is expected to begin due to a probable eyewall replacement cycle, the beginning of cold upwelling, and increasing southwesterly wind shear. On days 4 and 5, more rapid weakening is forecast due to Barbara moving over sub-26 deg C water temperatures and into vertical wind shear conditions of more than 20 kt. The new official intensity forecast is similar to the previous advisory, and is a little above the consensus guidance throughout the entire forecast period, closer to the Decay-SHIPS model. FORECAST POSITIONS AND MAX WINDS INIT 02/0300Z 11.7N 119.8W 85 KT 100 MPH 12H 02/1200Z 12.3N 121.7W 95 KT 110 MPH 24H 03/0000Z 12.9N 124.0W 110 KT 125 MPH 36H 03/1200Z 13.6N 125.9W 120 KT 140 MPH 48H 04/0000Z 14.4N 127.7W 115 KT 130 MPH 72H 05/0000Z 16.4N 131.0W 85 KT 100 MPH 96H 06/0000Z 18.0N 134.7W 65 KT 75 MPH 120H 07/0000Z 18.7N 139.6W 45 KT 50 MPH $$ Forecaster Stewart NNNN