The satellite presentation of Flossie has continued to improve this
evening, with a hint of an eye now possibly developing in the past
hour or so. The latest subjective Dvorak intensity estimates came in
at T4.0/65 knots and T3.5/55 knots from SAB and TAFB respectively.
The objective intensity estimates range from 56 to 62 knots at 00z
and have since increased to between 62 and 74 knots. Based on these
data and the improved satellite appearance, the initial intensity
has been raised to 65 knots for this advisory package, making
Flossie a hurricane.
Flossie is heading toward the west-northwest or 300/09 knots. This
motion with a gradual decrease in forward speed is expected during
the next several days as the cyclone is steered into a weakness in
the mid-level ridge to the northwest. The track forecast is very
close to the previous advisory and is closely aligned with a
blend of the latest HCCA, TVCE and FSSE consensus aids.
The environment will remain very conducive for strengthening during
the next 36 hours, with warm sea surface temperatures of 28/29C,
abundant mid-level moisture, and light vertical wind shear. In
fact, the latest SHIPS RI probabilities show a greater than 60%
chance of a 25-knot increase in 24 hours, and the official
forecast reflects this. Additional strengthening is forecast
through 36 hours, with the cyclone beginning to weaken by 48 hours
as it moves over cooler water. Rather rapid weakening will then
follow as Flossie moves over progressively cooler water and begins
to entrain dry mid-level air. The system is forecast to become a
post-tropical low by 72 hours and a post-tropical remnant low at
96 hours. The intensity forecast is on the high end of the
intensity aids, closest to SHIPS and NNIC, which show rapid
intensification.
KEY MESSAGES:
1. The outer bands of Tropical Storm Flossie should bring locally
heavy rainfall to coastal portions of the Mexican states of
Guerrero, Michoacán, Colima, and Jalisco through Wednesday.
Life-threatening flooding and mudslides are possible, particularly
in steep terrain.
2. Tropical storm conditions are expected in portions of the
tropical storm warning area in southwestern Mexico, tonight
through Tuesday.
FORECAST POSITIONS AND MAX WINDS
INIT 01/0300Z 16.5N 104.3W 65 KT 75 MPH
12H 01/1200Z 17.4N 105.7W 75 KT 85 MPH
24H 02/0000Z 18.2N 107.3W 90 KT 105 MPH
36H 02/1200Z 18.9N 108.7W 95 KT 110 MPH
48H 03/0000Z 19.5N 109.7W 85 KT 100 MPH
60H 03/1200Z 20.0N 110.4W 65 KT 75 MPH
72H 04/0000Z 21.0N 111.4W 50 KT 60 MPH...POST-TROPICAL
96H 05/0000Z 23.0N 113.5W 30 KT 35 MPH...POST-TROP/REMNT LOW
120H 06/0000Z 24.3N 116.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
$$
Forecaster Jelsema
