Tropical Storm Wilma Advisory Number 8
Statement as of 11:00 am EDT on October 17, 2005
...Wilma strengthening...Tropical Storm Warning issued for
Honduras...
At 11 am EDT...1500z...the government of Honduras has issued a
Tropical Storm Warning from the Honduras/Nicaragua border westward
to Cabo camaron.
A Tropical Storm Warning and a Hurricane Watch remain in effect for
the Cayman Islands.
For storm information specific to your area...including possible
inland watches and warnings...please monitor products issued
by your local weather office.
At 11 am EDT...1500z...the center of Tropical Storm Wilma was
located near latitude 16.3 north... longitude 80.0 west or about
220 miles... 355 km... south-southeast of Grand Cayman and about
230 miles... 370 km...east-northeast of Cabo Gracias a Dios on the
Nicaragua/Honduras border.
Wilma is moving toward the southwest near 5 mph ... 7 km/hr...and a
gradual turn to the west is expected over the next 24 hours.
Maximum sustained winds are near 45 mph... 75 km/hr...with higher
gusts. Additional strengthening is forecast during the next 24
hours...and Wilma could become a hurricane by tomorrow.
Tropical storm force winds extend outward up to 70 miles
...110 km...mainly to the south of the center.
Estimated minimum central pressure is 998 mb...29.47 inches.
The depression is expected to produce rainfall accumulations of
4 to 6 inches over the Cayman Islands and Jamaica... with isolated
amounts of 8 to 12 inches possible.
Repeating the 11 am EDT position...16.3 N... 80.0 W. Movement
toward...southwest near 5 mph. Maximum sustained
winds... 45 mph. Minimum central pressure... 998 mb.
An intermediate advisory will be issued by the National
Hurricane Center at 2 PM EDT followed by the next
complete advisory at 5 PM EDT.
Forecaster Franklin
Tropical Storm Wilma Discussion Number 8
Statement as of 11:00 am EDT on October 17, 2005
The development trend that we have been anticipating for a couple of
days is underway. Deep convection is being maintained very near
and south of the circulation center...with banding features
developing near the center in the southwest quadrant. Dvorak
classifications from TAFB and SAB were t3.0/45 kt...and a Quikscat
pass at 12z suggests winds are also 40-45 kt. The advisory
intensity is conservatively increased to 40 kt...and I expect
stronger winds when the reconnaissance aircraft arrives early this
afternoon. Oceanic and atmospheric conditions are favorable for
continued strengthening and there has been little change to the
official intensity forecast.
Wilma drove southward overnight but a westward component seems to
have returned...and the initial motion is estimated to be 235/4.
Model guidance has been extraordinarily inconsistent from run to
run and there is presently a huge spread in the guidance. What is
most puzzling is that the models that best anticipated the
southward motion overnight...the GFDL and the GFS...are way out
there on the eastern edge of the guidance envelope with a track
over western Cuba and into the extreme southeastern Gulf of Mexico.
The UKMET...NOGAPS...and ECMWF take Wilma into various parts of the
Yucatan Peninsula. There are important differences in the amount
of mid-level ridging over the western Gulf of Mexico in these
models that is affecting the ability of Wilma to connect with the
westerlies near the end of the forecast period. While it is
tempting to adjust the track to the right based on the recent
changes with the GFS and GFDL models...the fact that the 6z runs of
both models were initialized a bit too far north may mean that they
are too fast with the recurvature scenario. For now...I have made
little change to the official forecast. Clearly...confidence at
the longer ranges is unusually low. While the southward motion
overnight now requires a Tropical Storm Warning for
Honduras...given the uncertainties in track as well as the size of
the cyclonic envelope...it is a little premature to lower the watch
and warning for the Cayman Islands.
Forecaster Franklin
forecast positions and Max winds
initial 17/1500z 16.3n 80.0w 40 kt
12hr VT 18/0000z 16.2n 80.6w 50 kt
24hr VT 18/1200z 16.3n 81.5w 60 kt
36hr VT 19/0000z 16.5n 82.6w 70 kt
48hr VT 19/1200z 17.0n 83.7w 80 kt
72hr VT 20/1200z 18.5n 85.5w 90 kt
96hr VT 21/1200z 20.0n 86.5w 95 kt
120hr VT 22/1200z 22.5n 87.5w 95 kt
$$