000
WTPA41 PHFO 280851
TCDCP1
 
Tropical Storm Fausto Discussion Number  38
NWS Central Pacific Hurricane Center Honolulu HI   EP062026
Issued by NWS National Hurricane Center Miami FL
1100 PM HST Mon Jul 27 2026

Fausto has been struggling this evening as it moves into an
environment of stronger west-southwesterly vertical wind shear and
is already embedded in a very dry airmass, with mid-level relative
humidity values below 40 percent.  An Air Force Reserve
reconnaissance aircraft currently flying a mission in Fausto found
maximum 700 mb flight-level winds of 57 kt over the northeast
quadrant of the cyclone, and recent fixes indicate that the central
pressure has risen to near 1000 mb, up a few mb from the previous
flight.  The aircraft data and well as recent GPMI, AMSR-2, and
WSF-M microwave overpasses are in agreement that the vortex is 
tilted with height, with the low-level center located to the west of 
the mid-level center.  A recently received ASCAT pass shows that 
Fausto has a large area of light winds near the center, and 
strongest winds are located about 60 n mi to the north-northeast of 
the center.  Based on recent center fixes, the low-level center is 
now under the very southern edge of the main convective mass, so it 
wouldn't be surprising if the center becomes exposed over the next 
12 h as Fausto moves into an environment of stronger wind shear.  
The initial intensity is lowered to 55 kt for this advisory, which 
could be slightly generous.
 
Fausto is still moving toward the west-northwest at about the same
speed, about 285/13 kt.  There is little change to the track
forecast philosophy.  Fausto should continue to be steered on a
general west-northwestward track by the mid- to low level
environmental flow for the next several days.  The latest official
track forecast is practically unchanged from the previous NHC
advisory, and is closest to the HFIP Corrected Consensus (HCCA) as
well as the Google DeepMind ensemble mean.  On this track, Fausto
should pass to the north of the Hawaiian Islands Tuesday night
through late Wednesday.
 
Fausto is currently experiencing west-southwesterly wind shear of
20-25 kt, and the shear is forecast to increase to 30 kt in about 12
h, and to near 40 kt by hour 36.  This, combined with mid-level
relative humidity values remaining in the 30 to 35 percent range,
will lead to continued weakening of Fausto.  GFS and ECMWF simulated
satellite imagery indicate that by 36 h, Fausto may only be
producing a few puffs of convection, and the official forecast
still shows a 35-kt tropical storm at that time.  After 36 h, the
vortex should continue to spin down while possibility continuing to
produce intermittent bursts of convection.  Global models show the
system opening up into a trough around, or just after 72 h.  The
NHC intensity forecast is similar to the previous one and is near
the middle of the guidance envelope.  It is possible that Fausto
could dissipate a little sooner than forecast.
 
 
Key Messages:
 
1. Fausto is expected to continue weakening as it approaches the
Hawaiian Islands this week. Although the current forecast indicates
that the strongest winds and heaviest rainfall will remain north of
the islands, interests across Hawaii should continue to monitor the
progress of Fausto.
 
2. Surf generated by Fausto will continue to build westward
across Hawaii along exposed east-facing shores through Tuesday
as Fausto approaches and begins to pass north of the islands.
Large surf and strong currents will lead to dangerous conditions
along exposed shores. Please consult products from your local
weather office.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  28/0900Z 21.7N 150.3W   55 KT  65 MPH
 12H  28/1800Z 22.1N 152.1W   45 KT  50 MPH
 24H  29/0600Z 22.6N 154.4W   40 KT  45 MPH
 36H  29/1800Z 23.1N 156.8W   35 KT  40 MPH
 48H  30/0600Z 23.7N 159.4W   35 KT  40 MPH
 60H  30/1800Z 24.2N 162.0W   30 KT  35 MPH
 72H  31/0600Z 24.7N 164.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  01/0600Z...DISSIPATED
 
$$
Forecaster Hagen