Thread: Tropical Storm Lisa - East Atlantic - formerly TD14

That didn't last too long ...

Tropical Storm Lisa

000
wtnt34 knhc 251444
tcpat4
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tropical storm lisa advisory number 20
nws tpc/national hurricane center miami fl al142010
1100 am ast sat sep 25 2010

...lisa weakens to a tropical storm over the far eastern atlantic...


Summary of 1100 am ast...1500 utc...information
-----------------------------------------------
location...22.7n 28.2w
about 540 mi...865 km nnw of the cape verde islands
about 1060 mi...1705 km s of the azores
maximum sustained winds...70 mph...110 km/hr
present movement...n or 350 degrees at 12 mph...19 km/hr
minimum central pressure...990 mb...29.23 inches


watches and warnings
--------------------
there are no coastal watches or warnings in effect.


Discussion and 48-hour outlook
------------------------------
at 1100 am ast...1500 utc...the center of tropical storm lisa was
located near latitude 22.7 north...longitude 28.2 west. Lisa is
moving toward the north near 12 mph...19 km/hr...and this general
motion is forecast to continue through this afternoon. A gradual
turn toward north-northwest is expected later tonight or on sunday.

Maximum sustained winds are near 70 mph...110 km/hr...with higher
gusts. Gradual weakening is forecast during the next 48 hours.

Lisa is a small tropical cyclone. Tropical-storm-force winds extend
outward up to 60 miles...95 km from the center.

Estimated minimum central pressure is 990 mb...29.23 inches.


Hazards affecting land
----------------------
none.


Next advisory
-------------
next complete advisory...500 pm ast.

$$
forecaster stewart

Tropical storm lisa discussion number 21
nws tpc/national hurricane center miami fl al142010
500 pm ast sat sep 25 2010

conventional and microwave satellite imagery indicate westerly shear
is taking its toll on lisa with its upper-level anticyclone now
displaced more than 100 nmi to the east of the low-level center. As
a result...satellite intensity estimates have been rapidly
decreasing during the past 6 hours. The initial intensity of 45 kt
is based on a blend of satellite intensity estimates t3.5/55 kt
from tafb...t1.5/25 kt from sab...and an adt value of t3.0/45 kt
from uw-cimss.

The initial motion estimate is 350/10. Lisa remains on track and the
cyclone is expected to turn toward the north-northwest during the
next 12 hours or so...and continue that motion for the remainder of
the forecast period. The nhc model guidance is much more convergent
now...and the official forecast track is similar to the previous
advisory track and is a little to the right of the model consensus.

Westerly to southwesterly vertical shear is forecast to increase to
more than 30 kt by 24 hours...which could hasten the ongoing
weakening trend. The gfs-based ships model indicates dissipation by
48 hours...but the official forecast delays dissipation due to
intermittent bursts of deep convection possibly keeping the
circulation alive a little bit longer...which is similar to the
lgem...hwrf...and gfdl solutions. The official intensity forecast
is similar to the previous advisory and is a blend of the nhc
objective intensity guidance.


Forecast positions and max winds

initial 25/2100z 23.7n 28.4w 45 kt
12hr vt 26/0600z 24.7n 28.6w 40 kt
24hr vt 26/1800z 26.1n 28.8w 35 kt
36hr vt 27/0600z 27.4n 29.0w 30 kt
48hr vt 27/1800z 28.6n 29.3w 30 kt
72hr vt 28/1800z 30.7n 30.0w 25 kt...post-trop/remnt low
96hr vt 29/1800z 32.5n 30.5w 25 kt...post-trop/remnt low
120hr vt 30/1800z...dissipated

$$
forecaster stewart

wtnt44 knhc 260843
tcdat4
tropical depression lisa discussion number 23
nws tpc/national hurricane center miami fl al142010
500 am ast sun sep 26 2010

strong southwesterly shear continues to take a toll on lisa as the
center of the cyclone is exposed to the southwest of a small area
of remaining thunderstorm activity. The initial intensity is
lowered to 30 kt...based on a blend of dvorak satellite estimates
and an earlier ascat pass. The shear...along with dry air and cool
ssts...should cause continued weakening...and lisa is forecast to
degenerate to a remnant low in 12-24 hours.

The initial motion estimate is 345/8. A north-northwestward motion
is expected during the next few days as the cyclone moves between a
trough over the eastern atlantic and a ridge near northwestern
africa. The guidance has generally shifted westward this cycle...
And the official forecast has been adjusted in that direction.
Late in the forecast period...a surface high is expected to build
northwest of the azores which will likely cause the remnant low to
slow down and turn northwestward before it dissipates.


Forecast positions and max winds

initial 26/0900z 25.1n 29.0w 30 kt
12hr vt 26/1800z 26.0n 29.5w 25 kt
24hr vt 27/0600z 27.2n 30.2w 25 kt...post-trop/remnt low
36hr vt 27/1800z 28.5n 30.9w 25 kt...post-trop/remnt low
48hr vt 28/0600z 29.8n 31.3w 25 kt...post-trop/remnt low
72hr vt 29/0600z 31.5n 31.3w 25 kt...post-trop/remnt low
96hr vt 30/0600z 32.0n 31.5w 20 kt...post-trop/remnt low
120hr vt 01/0600z...dissipated

$$
forecaster brown

Wtnt44 knhc 262038
tcdat4
tropical depression lisa discussion number 25
nws tpc/national hurricane center miami fl al142010
500 pm ast sun sep 26 2010

a small area of deep convection is lingering over the northeastern
portion of the circulation of lisa. This convection...however...is
located over 100 n mi from the low-level center. In fact...deep
convection has not been within 100 n mi of the center for about the
last 11 hours. Therefore...lisa no longer qualifies as a tropical
cyclone and this is the last advisory issued by the national
hurricane center. Southwesterly shear of at least 30 kt is
expected to continue for the next day or so. This...coupled with a
stable atmosphere and a relatively cool ocean should prevent
regeneration.

The initial motion estimate is 335/6. The remnant low is expected
to continue moving north-northwestward to northward for the next
few days within the low-level flow.

Forecast positions and max winds

initial 26/2100z 26.1n 29.4w 25 kt...post-trop/remnt low
12hr vt 27/0600z 26.8n 30.1w 25 kt...post-trop/remnt low
24hr vt 27/1800z 27.9n 31.0w 25 kt...post-trop/remnt low
36hr vt 28/0600z 29.1n 31.4w 25 kt...post-trop/remnt low
48hr vt 28/1800z 30.2n 31.4w 20 kt...post-trop/remnt low
72hr vt 29/1800z 31.4n 31.1w 20 kt...post-trop/remnt low
96hr vt 30/1800z...dissipated

$$
forecaster cangialosi

So long, Lisa