WTPA42 PHFO 271532

TCDCP2



TROPICAL STORM ULIKA DISCUSSION NUMBER   5

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP192016

500 AM HST TUE SEP 27 2016



Satellite imagery indicates that Tropical Storm Ulika (oo-Lee-kah)

has become better organized overnight, with persistent deep

convection being maintained over the low-level circulation center.

Microwave imagery from a 27/1029Z GCOM and 27/1210Z AMSUB pass

support a strengthening system, showing an eyewall feature

developing. The latest Dvorak intensity estimates from PHFO, SAB,

and JTWC range from 2.0/30kt to 3.0/45kt, with the ADT from UW-CIMSS

showing 3.3/51kt. Based on the improving satellite presentation, the

initial intensity has been increased to 45 kt with this advisory.



The initial motion of the system is based on satellite

animations, and is set at 035 degrees at 4 kt. The system is

expected to continue to track toward the northeast, into a weakness

in the mid and upper-level ridge resulting from an upper level low

to the north of the cyclone, through tonight. Ulika is expected to

make a turn toward the north on Wednesday and Wednesday night,

followed by a turn toward the west Thursday as increasing westerly

vertical wind shear results in a more shallow system steered by the

low level trade wind flow. The system is expected to continue on a

westward track with a gradual increase in forward speed through the

end of the week, and weaken into a remnant low on Friday or Friday

night. The official forecast track has been nudged to the east of of

the previous advisory due to the increasingly deep and stronger

system, and is close to the multi-model GFEX and TVCN consensus

guidance.



Some intensification of Ulika is expected during the next 12 to 24

hours as the system remains over 28C SSTs, with minimal dry air

entrainment and weak vertical wind shear. In fact, SHIPS guidance

shows a 35 percent probability of rapid intensification of 25 kt or

more in 24 hours, so the system could increase more than currently

forecast. Wind shear is then forecast to increase Wednesday through

Thursday as upper level winds strengthen over the system. This

should lead to steady weakening, with the tropical cyclone becoming

a remnant low Friday or Friday night. The intensity forecast was

adjusted upward from the previous advisory and follows a blend of

the SHIPS, IVCN and HWRF guidance.





FORECAST POSITIONS AND MAX WINDS



INIT  27/1500Z 12.4N 140.0W   45 KT  50 MPH

 12H  28/0000Z 12.9N 139.7W   55 KT  65 MPH

 24H  28/1200Z 13.8N 139.3W   55 KT  65 MPH

 36H  29/0000Z 14.7N 139.0W   55 KT  65 MPH

 48H  29/1200Z 15.6N 139.1W   45 KT  50 MPH

 72H  30/1200Z 16.8N 141.1W   35 KT  40 MPH

 96H  01/1200Z 17.0N 144.5W   30 KT  35 MPH...POST-TROP/REMNT LOW

120H  02/1200Z 17.0N 149.0W   25 KT  30 MPH...POST-TROP/REMNT LOW



$$

Forecaster Jelsema