Tropical Cyclone Discussion

040
WTPA44 PHFO 070840
TCDCP4
 
Tropical Storm Pena Discussion Number   3
NWS Central Pacific Hurricane Center Honolulu HI   CP042026
Issued by NWS National Hurricane Center Miami FL
1100 PM HST Fri Nov 06 2026

The latest satellite imagery indicates that Pena has re-developed
convective banding closer to the cyclone's center. In addition, a 
just-received GMI overpass suggests that the low-level structure 
has become better defined, with the possible formation of a small 
inner core.  Satellite intensity estimates have generally nudged 
upward a little since the last advisory, and based on this trend 
the initial intensity is increased to 45 kt. The latest 
scatterometer overpass missed the inner core, but did show an area 
of 25-30 kt winds 60-150 n mi away from the center in the eastern 
semicircle.
 
The initial motion is westward or 275/10 kt. Pena should be steered 
generally westward for the next several days by a large low- to 
mid-level ridge to the north of the cyclone, with a west- 
northwestward motion possible near the end of the forecast period. 
The track forecast guidance is in generally good agreement with 
this scenario, although some of the models show a south of west 
motion during the 24-60 h period. The new track forecast is similar 
to the previous forecast through 72 h and is a little south of the 
previous forecast at 96 and 120 h.
 
The intensity forecast still has some confidence issues.  The
overall environment still seems to be favorable, with warm sea
surface temperatures, a moist air mass, and light shear for at
least the next four days. This results in the statistical-
dynamical guidance showing steady strengthening. However, the
dynamical model guidance is in poor agreement on how much
strengthening will occur and if there will be any strengthening at
all. To highlight the spread of just the global models, the ECMWF
shows strengthening through the next five days, the GFS and the
Canadian show little development through three days followed by
some strengthening, and the UKMET shows essentially no
strengthening at all during the forecast period.  Given the lack of
model consensus even on trends in the forecast intensities, the 
intensity forecast calls for gradual strengthening in best 
agreement with the SHIPS model. The new forecast is an update of
the previous forecast.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  07/0900Z 11.4N 152.4W   45 KT  50 MPH
 12H  07/1800Z 11.4N 153.9W   50 KT  60 MPH
 24H  08/0600Z 11.4N 155.7W   55 KT  65 MPH
 36H  08/1800Z 11.2N 157.5W   60 KT  70 MPH
 48H  09/0600Z 11.2N 159.2W   60 KT  70 MPH
 60H  09/1800Z 11.2N 160.9W   60 KT  70 MPH
 72H  10/0600Z 11.3N 162.9W   60 KT  70 MPH
 96H  11/0600Z 11.6N 167.3W   65 KT  75 MPH
120H  12/0600Z 12.9N 173.4W   65 KT  75 MPH