Tropical Cyclone Discussion

187
WTPA44 PHFO 110836
TCDCP4
 
Tropical Storm Pena Discussion Number  19
NWS Central Pacific Hurricane Center Honolulu HI   CP042026
Issued by NWS National Hurricane Center Miami FL
1100 PM HST Tue Nov 10 2026
 
Convection continues to wax and wane near Pena, with most of the
current activity well north of the center.  A WSFM microwave pass
and a SAR pass from a few hours ago showed the system was moving 
south of west, and all of the tropical-storm-force winds were
north of the center.  The current intensity is kept at 40 kt,
consistent with the SAR data and just above a recently received 
ASCAT scatterometer pass.
 
Pena's motion is estimated to be 260/8 kt. The cyclone continues to
be steered by a high pressure ridge centered over the subtropical 
Central Pacific, and the high should cause the storm to accelerate 
westward during the next few days.  The most notable change is that 
the guidance has shifted slightly to the south, probably because 
the storm is still losing latitude.  The new NHC track forecast is 
nudged in that direction, close to a blend of the Google DeepMind 
ensemble and the HFIP Corrected Consensus models.
 
Despite the storm being over very warm waters with decent mid-level
humidity values, there is some westerly shear noted below the
outflow layer because of stronger low-level flow and weak mid- 
to upper-level flow. The environment is not expected to change much 
during the next few days, but a small increase in shear and 
decrease in moisture is noted by Thursday.  This should be enough 
to cause weakening by then, and the system could dissipate in a few 
days while it is near the International Dateline due to a 
persistence of these unfavorable conditions, or an increase in 
forward speed that causes the weak cyclone to open up into a 
trough.  The intensity forecast is reduced slightly from the last 
one, and the dissipation time has been brought forward, similar to 
the latest global model consensus solution.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  11/0900Z 10.1N 166.7W   40 KT  45 MPH
 12H  11/1800Z 10.0N 168.4W   40 KT  45 MPH
 24H  12/0600Z 10.2N 171.2W   40 KT  45 MPH
 36H  12/1800Z 10.6N 174.3W   35 KT  40 MPH
 48H  13/0600Z 11.0N 177.4W   35 KT  40 MPH
 60H  13/1800Z 11.4N 179.5E   30 KT  35 MPH
 72H  14/0600Z...DISSIPATED