Tropical Storm Lisa Advisory Number 28
Statement as of 5:00 am AST on September 26, 2004
...Lisa posing no immediate threat to land...
At 5 am AST...0900z...the center of Tropical Storm Lisa was located
near latitude 18.4 north...longitude 46.0 west or about 1460
miles...2350 km... west of the Cape Verde Islands.
Lisa is moving toward the north near 8 mph...13 km/hr. A
north-northwestward motion is expected over the next 24 hours.
Maximum sustained winds are near 50 mph... 85 km/hr...with higher
gusts. Little change in strength is forecast during the next
24 hours.
Tropical storm force winds extend outward up to 115 miles
...185 km from the center.
Estimated minimum central pressure is 1001 mb...29.56 inches.
Repeating the 5 am AST position...18.4 N... 46.0 W. Movement
toward...north near 8 mph. Maximum sustained
winds... 50 mph. Minimum central pressure...1001 mb.
The next advisory will be issued by the National
Hurricane Center at 11 am AST.
Forecaster Franklin
-----------------------------------------------------------
Statement as of 5:00 am EDT on September 26, 2004
the location of Lisa is something of a mystery this morning...as
Dvorak position estimates at 06z from TAFB and SAB were about 70
miles apart...and the most recent microwave passes over the cyclone
were not especially helpful in resolving the center. What data do
exist suggest that the center may be a little east of the previous
track...but given the uncertainty I have tried to maintain
continuity with previous estimates. The initial motion is
estimated to be 350/7. Position uncertainty leads to poor
confidence in the Dvorak intensity estimates...and the initial
intensity is held at 45 kt in accord with the Quikscat pass about 9
hours ago. Lisa is somewhere near the northwest side of the deep
convection. Water vapor winds and imagery show a band of
westerlies over and northwest of the storm...and the GFS and UKMET
show this shear should increase over the next day or two. The
intensity forecast shows little change over this period...and is a
little below the SHIPS and GFDL guidance. After that...upper-level
ridging near the cyclone could allow for some intensification.
Lisa is southeast of a deep trough in the central Atlantic...but the
NOGAPS...UKMET...and GFS all agree that this trough should lift out
and leave Lisa behind. Through 72 hours the track model guidance
is pretty tightly clustered on a turn back to the north-northwest
as the trough lifts out. Near the end of the forecast period there
is some divergence in the guidance...with the GFS and NOGAPS
turning Lisa northeastward ahead of the remnants of Jeanne...and
the UKMET and GFDL still showing a westward component of motion.
The FSU superensemble is also on the left side of the guidance
envelope. The official forecast is to the right of the previous
advisory initially to reflect the recent fixes and apparent
motion...but is adjusted to the left late in forecast period to be
in better agreement with the GFDL...superensemble...and global
model consensus.
Forecaster Franklin
forecast positions and Max winds
initial 26/0900z 18.4n 46.0w 45 kt
12hr VT 26/1800z 19.7n 46.3w 50 kt
24hr VT 27/0600z 21.4n 47.0w 50 kt
36hr VT 27/1800z 23.0n 47.7w 50 kt
48hr VT 28/0600z 24.5n 48.5w 55 kt
72hr VT 29/0600z 26.5n 50.0w 65 kt
96hr VT 30/0600z 29.0n 51.5w 65 kt
120hr VT 01/0600z 32.0n 52.0w 65 kt
5 DAY TRACK -- http://www.wunderground.com/tropical/tr ... _5day.html
5 AM LISA -- 50 MPH... but where is center, hmmm?
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