|Hurricane Barbara||Winds: 65 kt|
|Pressure: 977 mbar|
|Advisory 22 / 2:00 AM PDT Fri July 5, 2019|
Barbara continues to weaken. Infrared satellite imagery shows the central dense overcast waning in size and the convection on the southern side of the mid-level center has eroded significantly revealing the low-level center and the degree of vertical tilt within the system. Dvorak estimates remain, surprisingly the same at 06z as they were six hours prior, with SAB at T4.5/77kt and T5.0/90kt from TAFB. UW-CIMSS ADT CI values have fallen to T4.9/88kt, but given the current weakening trend, these estimates have been thrown out and the initial intensity has been set to 65 kts based on subjective estimates, keeping Barbara a minimal hurricane for this advisory.
Southwesterly shear is beginning to significantly affect Barbara, displacing the mid-level center to the northeast of the low-level circulation, which will adversely affect the system. Combined with sub-25C sea surface temperatures and decreasing relative humidity, the storm is expected to continue weakening at a rapid pace, perhaps even faster today than it has so far. This will bring the system to the breaking point by day 2, by which point it is expected to be a remnant low.
Barbara continues its northwest motion this morning, which it is expected to continue throughout the day, but as the storm quickly loses strength and the vertical tilt takes the low-level center out from under the mid-levels of the system into the influence of the easterly trade winds, the system should begin to turn more westerly shortly. A ridge will build in to the north today as well, which will also amplify this westerly to south of westerly motion. The weakened storm or its remnants will continue on a south of west track toward Hawaii which it will approach around day 4, but will likely have dissipated by then, resulting in only minimal impact.
FORECAST MAX WINDS
INIT 05/0900Z 65 KT 75 MPH
12H 05/1800Z 50 KT 55 MPH
24H 06/0600Z 35 KT 40 MPH
36H 06/1800Z 30 KT 35 MPH
48H 07/0600Z 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 08/0600Z 20 KT 25 MPH...POST-TROP/REMNT LOW96H 09/0600Z...DISSIPATED