|Hurricane Barbara||Winds: 75 kt|
|Pressure: 969 mbar|
|Advisory 21 / 8:00 PM PDT Thu July 4, 2019|
The demise of Barbara draws nearer. Satellite imagery reveals that the hurricane's eye has finally become cloud filled. The central dense overcast remains surprisingly symmetrical given the assessed amount of wind shear by the SHIPS model. It is worth pointing out that the SHIPS output depends on a large grid size. Therefore, it is possible that SHIPS is assessing high upper-level winds to the southwest of Barbara that have not quite yet reached the hurricane. Nonetheless, current intensity estimates have fallen to T4.5/77kt from SAB and T5.0/90kt from TAFB. UW-CIMSS ADT raw values are in the middle of a freefall now that the eye has become obscured, but the current intensity value is higher at T5.3/97kt. A blend of these values would support holding the initial intensity steady. However, a 0122z microwave pass indicated that the entire southern eyewall of Barbara had been eroded by the presence of dry air. Clearly, that is not the staple of a potent hurricane, and I have elected to side with SAB in assigning a current strength of 75kt.
If downright hostile upper-level winds have not reached Barbara yet, they will in short order. The combination of this wind shear, ocean temperatures under 25C, and mid-level relative humidity values under 55 percent should prompt rapid weakening over the next few days, and Barbara is expected to lose its status as a tropical cyclone in about 48 hours, although this could occur sooner. Dissipation is expected about 4 days from now.
The hurricane is moving northwest and will continue on this motion overnight into tomorrow morning. After that time, mid-level ridging should build to the cyclone's north and force it on a westward trajectory. As Barbara loses intensity, it will be steered by the low-level easterly trade wind flow across the Pacific, moving south of due west until dissipation. This track will bring it close to the Hawaiian Islands, where enhanced rainfall is expected but consequences are not likely to be severe.
FORECAST MAX WINDS
INIT 05/0300Z 75 KT 90 MPH
12H 05/1200Z 55 KT 65 MPH
24H 06/0000Z 40 KT 45 MPH
36H 06/1200Z 30 KT 35 MPH
48H 07/0000Z 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 08/0000Z 20 KT 25 MPH...POST-TROP/REMNT LOW96H 09/0000Z...DISSIPATED