(full maps & details) 5am Hurricane Updates (full maps & details)

HURRICANE ERICK (at it’s closest currently projected approach to Kohala, Flossie should be downgraded to Tropical Storm with winds around 60mph.)

500 AM HST Wed Jul 31 2019

Satellite imagery continues to show Hurricane Erick becoming less
well organized. The eye has become ragged and the area of coldest
cloud tops over the center continues to shrink and become less
symmetrical. Subjective Dvorak current intensity estimates were
6.0/115 kt from JTWC and 5.5/102 kt from SAB and PHFO, while ADT is
5.0. The initial intensity estimate for this advisory has been
decreased slightly to 105 kt. Erick remains a category 3 hurricane
on the Saffir-Simpson Hurricane Wind Scale. Erick continues moving
slightly north of west with little change in forward speed. The
initial motion estimate for this advisory is 280 degrees at 13 mph.

There has been little change in the philosophy for the forecast
track or intensity. Guidance remains consistent showing Erick
tracking slightly north of west for the next 48 hours as it
moves south of a strong subtropical ridge, passing south of the Big
Island of Hawaii Thursday night. After passing the islands, Erick
will gradually turn towards the northwest. This track will take
Erick into an area of stronger vertical wind shear associated with a
persistent trough aloft. That environment is expected to produce
steady weakening.

FORECAST POSITIONS AND MAX WINDS

INIT 31/1500Z 14.5N 147.5W 105 KT 120 MPH
12H 01/0000Z 14.8N 149.0W 95 KT 110 MPH
24H 01/1200Z 15.3N 151.3W 80 KT 90 MPH
36H 02/0000Z 15.9N 153.7W 65 KT 75 MPH
48H 02/1200Z 16.4N 156.2W 50 KT 60 MPH
72H 03/1200Z 17.6N 160.8W 40 KT 45 MPH
96H 04/1200Z 19.5N 164.0W 35 KT 40 MPH
120H 05/1200Z 21.0N 166.0W 30 KT 35 MPH

HURRICANE FLOSSIE

500 AM HST Wed Jul 31 2019

Flossie has the structure of a strongly sheared cyclone. Several
recent microwave passes have revealed that Flossie’s center is
displaced to the northwest of all of its deep convection, and IR
imagery shows a sharp cloud-top temperature gradient in the
northwest quadrant of the hurricane. A blend of Final-T and CI
numbers from TAFB and SAB is the basis for the initial intensity of
65 kt, however it is certainly possible that Flossie is weaker than
that.

Given the current structure of Flossie (or lack thereof), a
substantial change was made to the intensity forecast. The global
models indicate that the current shear affecting the cyclone will
likely continue for another 24 h or so and Flossie is now forecast
to become a tropical storm during that time. In fact, the
statistical guidance suggests that Flossie will merely gradually
weaken for the next 5 days. On the other hand, the GFS, ECMWF, and
regional hurricane models indicate that the upper-level environment
could become more favorable in a few days, so some
re-intensification is possible at that time. The NHC forecast now
closely follows the intensity consensus through 48 h and then blends
back toward the previous forecast at 72 h and beyond, still favoring
the dynamical models at that time.

On the other hand, very little adjustment was required to the track
forecast. The initial motion is 285/13 kt, and a persistent
mid-level ridge to the north should keep Flossie moving
west-northwestward or westward at a steady forward speed for the
next 4 to 5 days. The track guidance remains very tightly clustered,
and the NHC forecast is very close the typically reliable TVCE and
HCCA aids.

FORECAST POSITIONS AND MAX WINDS

INIT 31/1500Z 14.0N 125.8W 65 KT 75 MPH
12H 01/0000Z 14.5N 127.7W 60 KT 70 MPH
24H 01/1200Z 15.2N 130.3W 60 KT 70 MPH
36H 02/0000Z 15.8N 133.0W 65 KT 75 MPH
48H 02/1200Z 16.2N 135.7W 65 KT 75 MPH
72H 03/1200Z 17.2N 141.3W 75 KT 85 MPH
96H 04/1200Z 17.8N 146.5W 75 KT 85 MPH
120H 05/1200Z 19.0N 151.5W 60 KT 70 MPH