Tropical Storm 28w (Twenty-eight) now develops heading Iwo To

At 050000z, tropical storm 28w (twentyeight) was located
near 23.4n 144.6e, approximately 195 nm east-southeast of iwo to,
and had tracked east-northeastward at 18 knots over the past six
hours. Maximum sustained surface winds were estimated at 35 knots
gusting to 45 knots. See ref a (wtpn31 pgtw 050300) for the final
warning on this system.

Advisory:

816

wtpn31 pgtw 050300
msgid/genadmin/navmarfcstcen Pearl Harbor hi/jtwc//
subj/tropical cyclone warning//
rmks/
1. Tropical storm 28w (twentyeigh) warning nr 001
upgraded from tropical depression 28w
01 active tropical cyclone in northwestpac
Max sustained winds based on one-minute average
wind radii valid over open water only
---
warning position:
050000z --- near 23.4n 144.6e
movement past six hours - 065 degrees at 18 kts
position accurate to within 060 nm
position based on center located by satellite
present wind distribution:
Max sustained winds - 035 kt, gusts 045 kt
wind radii valid over open water only
becoming extratropical
repeat posit: 23.4n 144.6e
---
forecasts:
12 hrs, valid at:
051200z --- 26.0n 147.4e
Max sustained winds - 035 kt, gusts 045 kt
wind radii valid over open water only
extratropical
vector to 24 hr posit: 050 deg/ 24 kts
---
24 hrs, valid at:
060000z --- 28.9n 151.8e
Max sustained winds - 035 kt, gusts 045 kt
wind radii valid over open water only
extratropical
---
remarks:
050300z position near 24.1n 145.3e.
Tropical Storm (TS) 28w (twentyeight), located approximately 195 nm
east-southeast of iwo to, has tracked east-northeastward at 18 knots
over the past six hours. Over the last 12 hours, animated infrared
and multispectral satellite imagery show sustained deep convection
near the low level circulation center (LLCC) despite vertical wind
shear in excess of 30 knots. Additionally, a 042039z SSMI microwave
image shows improved wrapping into the system center as well as a
symmetric LLCC. Recent AMSU cross sections also depict the continued
presence of a warm core. At 040000z, Dvorak estimates from pgtw have
come up to 35 knots and knes reported an estimate of 35 knots at
041500z. Ts 28w is currently also showing signs of beginning an
extratropical transition. The warm anomalies in the AMSU cross
sections have dropped from two degrees at 040900z to one degree at
041600z. Additionally, the greatest extent of deep convection has
shifted to the northeast of the system center and total precipitable
water (tpw) products show the intrusion of dry air from the west-
southwest as well as an encroaching frontal zone located to the
northwest. Ts 28w should complete its transition into a baroclinic
system over the next 12 hours as it tracks under increasingly
unfavorable vertical wind shear, over sea surface temperatures less
than 26 degrees celcius, and the inflow of cooler, drier air breaks
down the warm core aloft. This is the final warning on this system
by the Joint Typhoon Warning Center (navmarfcstcen). The system will
be closely monitored for signs of regeneration. Maximum significant
wave height at 050000z is 12 feet.//