Tropical Cyclone Discussion

216
WTPA44 PHFO 090839
TCDCP4
 
Tropical Storm Pena Discussion Number  11
NWS Central Pacific Hurricane Center Honolulu HI   CP042026
Issued by NWS National Hurricane Center Miami FL
1100 PM HST Sun Nov 08 2026
 
Satellite imagery indicates that the convective structure associated 
with Pena has changed little over the past several hours. Deep 
convection has mostly remained confined to intermittent bursts near 
and north of the circulation, likely due to light to moderate 
southerly vertical wind shear affecting it. The latest subjective 
and objective intensities remain in the 35 to 45 kt range. Given 
these intensities and the steady satellite presentation, the initial 
intensity is held at 40 kt. 
 
The initial motion is westward, or 270/8 kt. This general motion is 
expected to continue during the next 48 to 60 h as a low- to 
mid-level ridge builds to the north. Thereafter, a gradual turn 
toward the west-northwest is forecast as a weakness develops in the 
ridge in response to a shortwave trough moving across the 
northwestern Pacific. An increase in forward speed is expected 
around day 3 and should continue into day 4. Track guidance remains 
in good agreement during the next couple of days, but the 
cross-track spread increases thereafter, with some of the regional 
hurricane models maintaining a more westward track. In contrast, the 
GFS, ECMWF, and consensus aids support a gradual turn toward the 
west-northwest. These differences could be partly related to how the 
models handle the cyclone's intensity, with weaker solutions 
becoming increasingly steered by the low-level flow. The NHC track 
forecast is essentially unchanged from the previous prediction and 
lies near the HFIP Corrected Consensus (HCCA). 
 
Light to moderate southerly vertical wind shear and potentially some 
drier mid-level air appear to be limiting Pena's ability to 
strengthen. Although guidance indicates that the shear should 
decrease during the next 12 to 24 h, only a few intensity models 
support modest strengthening over the next several days, possibly 
due to occasional intrusions of dry mid-level air. Toward the end of 
the forecast period, vertical wind shear is expected to increase out 
of the west-southwest, which, combined with increasingly dry 
mid-level air, should favor some weakening. The latest NHC intensity 
forecast is very similar to the previous prediction and lies near 
the middle to upper end of the guidance envelope. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/0900Z 11.3N 158.4W   40 KT  45 MPH
 12H  09/1800Z 11.3N 160.4W   40 KT  45 MPH
 24H  10/0600Z 11.2N 162.6W   40 KT  45 MPH
 36H  10/1800Z 11.0N 164.6W   45 KT  50 MPH
 48H  11/0600Z 11.0N 166.6W   45 KT  50 MPH
 60H  11/1800Z 11.1N 169.3W   45 KT  50 MPH
 72H  12/0600Z 11.4N 171.8W   45 KT  50 MPH
 96H  13/0600Z 12.8N 178.4W   40 KT  45 MPH
120H  14/0600Z 14.3N 177.1E   40 KT  45 MPH