245 
abio10 pgtw 121800
msgid/genadmin/joint typhoon wrncen Pearl Harbor hi//
subj/significant tropical weather advisory for the Indian
/Ocean/121800z-131800zfeb2012//
ref/a/msg/joint typhoon wrncen Pearl Harbor hi/121351zfeb2012//
ampn/ref a is a tropical cyclone warning.//
Rmks/
1. North Indian Ocean area (Malay Peninsula west to coast of Africa):
   a. Tropical cyclone summary: none.
   B. Tropical disturbance summary: none.
2. South Indian Ocean area (135e west to coast of Africa):
   a. Tropical cyclone summary:
      (1) at 121200z, tropical cyclone 12s (giovanna) was located
near 17.7s 56.6e, approximately 200 nm north-northeast of La
Reunion, had tracked westward at 10 knots over the past six hours.
Maximum sustained surface winds were estimated at 100 knots gusting
to 125 knots. See ref a (wtxs31 pgtw 121500) for further details.
      (2) no other tropical cyclones.
   B. Tropical disturbance summary:
      (1) the area of convection previously located near 11.5s
104.7e, is now located near 12.1s 100.0e, approximately 145 nm east
of Cocos Island, Australia. A 12-hour enhanced infrared satellite
imagery animation shows the formative banding along the west-south
perimeter of the system has deepened and arced tighter into a well-
defined low level circulation center (LLCC). Additionally, a series
of microwave satellite images depicts steady consolidation of
convective bands wrapping into the llcc; the latest, a 121455z AMSU-
b pass, depicts a full wrap of low level reflectivities flanked to
the south by a spiraling feeder band. Upper level analysis reveals,
the disturbance is 5 degrees equatorward of a ridge axis in a zone
of light to moderate (05-15 knot) easterly vertical wind shear
(vws). As the system gets closer to the ridge axis, the vws is
expected to weaken. Also, water vapor satellite animation indicates
improving poleward outflow. Maximum sustained surface winds are
estimated at 20 to 25 knots. Minimum sea level pressure is estimated
to be near 1005 mb. In view of the improving upper level
environment, the potential for the development of a significant
tropical cyclone within the next 24 hours is upgraded to medium.
      (2) no other suspect areas.//