Tropical Weather Discussion

000 

abio10 pgtw 230300
msgid/genadmin/joint typhoon wrncen Pearl Harbor hi//
subj/significant tropical weather advisory for the Indian Ocean
/reissued/230300z-231800zapr2018//
ref/a/msg/joint typhoon wrncen Pearl Harbor hi/220721zapr18//
ref/b/msg/joint typhoon wrncen Pearl Harbor hi/230252zapr18//
narr/ref a is a tropical cyclone formation alert. Ref b is a
/tropical cyclone formation alert reissued.//
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: none.
   B. Tropical disturbance summary:
      (1) the area of convection (invest 96s) previously located
near 4.9s 80.0e, is now located near 4.5s 81.5e, approximately 568
nm east-northeast of Diego Garcia. Animated multispectral satellite
imagery depicts a broad, slowly-consolidating low-level circulation
center (LLCC) with deep convective banding over the southern
semicircle wrapping into the western semicircle of the LLCC. A
220233z NOAA-18 89ghz image indicates fragmented deep convective
banding and broad shallow banding, however, a recent scatsat image
shows 25 to 30 knot winds associated with the aforementioned deep
convective banding. Upper-level analysis indicates low to moderate
(15 to 25 knots) vertical wind shear offset by near-radial outflow
and strong divergence aloft associated with a point source
positioned over the system. Additionally, SST values of 29 to 30c
are conducive for further development. Dynamic model guidance
depicts a generally south-southeastward to southward track over the
next two days with gradual strengthening.  Maximum sustained
surface winds are estimated at 25 to 30 knots. Minimum sea level
pressure is estimated to be near 1004 mb. The potential for the
development of a significant tropical cyclone within the next 24
hours remains high. See ref a (wtxs21 pgtw 220730) for further
details.
      (2) the area of convection (invest 93s) previously located
near 11.1s 50.6e, is now located near 12.9s 51.4e, approximately
550 nm north-northwest of La Reunion. Animated enhanced infrared
imagery and a 230007z ssmis 91 ghz microwave image depict an
obscured low level circulation center (LLCC) with the majority of
the convection located in the southern and eastern quadrants.
Environmental analysis shows that the system is located in a
favorable development area with low (10-15 knots) vertical wind
shear, strong poleward outflow, and warm sea surface temperatures
(28-29 c). Global models are split on continued intensification by
tau 24 as the system passes just off the Madagascar coastline on a
south-southeastward trajectory. Maximum sustained surface winds are
estimated at 25 to 30 knots. Minimum sea level pressure is
estimated to be near 1000 mb. The potential for the development of
a significant tropical cyclone within the next 24 hours remains
high. See ref b (wtxs22 pgtw 230300) for further details.
      (3) no other suspect areas.
3. Justification for reissue: area in para 2.B.(1) remains high and
tropical cyclone formation alert reissued.//

View All Hurricanes and Tropical Cyclones

Category 6

Welcome to Category 6. This is the collective home for Weather Underground's featured writeups by Dr. Jeff Masters (right), Bob Henson (left), Chris Burt, and other regular contributors.

Learn more about and the hurricane season in our hurricane archive.

View All Hurricanes and Tropical Cyclones

Hurricane Archive

All Atlantic Storms (1851-2018)

Named Storms for 2016

Historical Hurricane Statistics


Articles of Interest