067
WTPZ41 KNHC 070856
TCDEP1

Hurricane Priscilla Discussion Number  11
NWS National Hurricane Center Miami FL       EP162025
200 AM MST Tue Oct 07 2025

Priscilla is strengthening early this morning. The inner core
structure has improved, with deep convective cloud tops surrounding
the center of the hurricane. An eye feature has recently emerged in
proxy-visible and infrared satellite images. ASCAT-C data from 04
UTC show the tropical-storm-force wind field remains quite broad,
but the radius of maximum wind appears to have contracted from prior
estimates. The initial intensity is raised to 85 kt, representing a
blend of recent UW-CIMSS DPRINT estimates (79-87 kt) and a 5.0/90 kt
Dvorak classification from TAFB at 06 UTC.

The intensity of Priscilla is likely to peak in the next 12-24 h
while the hurricane remains over warm waters and in a moist,
moderate shear environment. Given the rapidly improving satellite
structure, the NHC forecast shows Priscilla nearing major hurricane
strength later today, in best agreement with the HAFS regional
models. Thereafter, the hurricane is expected to move over
progressively cooler waters and into a drier mid-level environment
while gaining latitude. Thus, the NHC forecast calls for steady
weakening beginning Wednesday and continuing through the rest of the
week. Southwesterly shear is forecast to increase over Priscilla as
it approaches the Baja California peninsula in 96-120 h, and
Priscilla could become post-tropical by late Friday or Saturday if
its convection is stripped away as shown in the GFS and ECMWF
simulated satellite imagery. This enhanced moisture is likely to be
transported northward over portions of the southwestern U.S. late
this week, resulting in the potential for heavy rainfall.

The hurricane is moving northwestward (310/9 kt) around the
southwestern portion of a mid-level ridge over northern Mexico. This
motion should continue for the next couple of days while the center
of Priscilla moves parallel to, but remains offshore of, the
southern Baja California peninsula. By Thursday, an amplifying
trough off the U.S. West Coast is forecast to erode the steering
ridge to the north of Priscilla. The weakness in the ridge should
induce a northward turn later this week and into the weekend. The
updated NHC track forecast lies slightly to the left of the
previous prediction. This is mostly related to an initial position
adjustment based on earlier microwave and scatterometer data that
indicated Priscilla was slightly south of previous estimates.


KEY MESSAGES:

1.  Tropical storm conditions are possible along the Baja California
Sur Pacific coastline within the Tropical Storm Watch area later
today into Wednesday. Interests elsewhere in the Baja California
peninsula should monitor the progress of Priscilla.

2.  Heavy rainfall associated with Priscilla will impact portions of
southern Baja California Sur, which could result in flash flooding,
particularly in areas of higher terrain.

3.  Swells generated by Priscilla are affecting portions of the
coast of southwestern and west-central Mexico as well as the coast
of the southern Baja California peninsula. These swells are likely
to cause life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT  07/0900Z 19.4N 109.5W   85 KT 100 MPH
 12H  07/1800Z 20.0N 110.4W   95 KT 110 MPH
 24H  08/0600Z 20.9N 111.8W   95 KT 110 MPH
 36H  08/1800Z 21.9N 113.0W   85 KT 100 MPH
 48H  09/0600Z 23.0N 114.2W   70 KT  80 MPH
 60H  09/1800Z 24.3N 115.1W   55 KT  65 MPH
 72H  10/0600Z 25.5N 115.4W   45 KT  50 MPH
 96H  11/0600Z 27.7N 115.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  12/0600Z 30.5N 114.0W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Reinhart