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Hurricane Barbara Discussion Number  18
NWS National Hurricane Center Miami FL       EP022019
1100 AM HST Thu Jul 04 2019

The eye of Barbara has gradually been filling in during the day,
with eyewall convection eroding somewhat on the south side.  In
addition, the cloud pattern has become elongated to the north -- a
sign that southwesterly shear is affecting the circulation. A blend
of the satellite intensity estimates, with more weight on the
subjective estimates, gives 85 kt as the initial wind speed. Barbara
should rapidly weaken over the next day or so due to cool waters,
increasing southwesterly shear, and dry air entrainment. The cyclone
is forecast to weaken into a tropical storm by 24 hours and
degenerate into a post-tropical cyclone near or just before it
enters the Central Pacific basin. The new NHC prediction is similar
to the previous one, close to the model consensus.

Barbara continues moving northwestward, or 310/10 kt. This general
path is forecast until tomorrow when a mid-level ridge builds to
north of the cyclone, causing a slightly faster west-northwestward
motion.  As Barbara weakens, it should turn westward and accelerate
on Saturday, steered by the low-level flow. The overall model
guidance envelope is virtually unchanged from the previous one, and
no significant changes were made to the forecast. All of the models
dissipate the cyclone east of the Hawaiian Islands, although the
remnants could move across that area in 4-5 days.

FORECAST POSITIONS AND MAX WINDS

INIT  04/2100Z 16.7N 130.8W   85 KT 100 MPH
 12H  05/0600Z 17.6N 132.1W   70 KT  80 MPH
 24H  05/1800Z 18.6N 134.1W   55 KT  65 MPH
 36H  06/0600Z 19.1N 136.6W   45 KT  50 MPH
 48H  06/1800Z 19.2N 139.3W   35 KT  40 MPH...POST-TROPICAL
 72H  07/1800Z 18.9N 145.6W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  08/1800Z 18.9N 152.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  09/1800Z...DISSIPATED

$$
Forecaster Blake

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