264
WTPZ42 KNHC 031458
TCDEP2

Hurricane Lorena Discussion Number   7
NWS National Hurricane Center Miami FL       EP122025
800 AM MST Wed Sep 03 2025

Satellite imagery and radar data from the Los Cabos radar in Mexico
indicate that Lorena continues to become better organized. Radar
imagery shows Lorena`s eye becoming better defined, with a
completely closed and circular eyewall.  Dvorak estimates from TAFB
and SAB were both T-4.0/65 kt, with the UW-CIMSS numbers ranging
from 55-68 kt.  However, the improvement over the last few hours
seen in radar images and GOES West satellite images suggest that
Lorena is likely stronger now.  The initial intensity is estimated
at 70 kt, and it is possible this may be a bit conservative.  An Air
Force Reserve reconnaissance aircraft is currently enroute to
Lorena, which should provide a better estimate of the intensity
in a couple of hours from now.

Lorena has rapidly intensified over the past 24 hours.  Continued
rapid strengthening is likely for another 12 to 18 hours as Lorena
remains over warm water and in low wind shear conditions, and the
peak intensity forecast of 85 kt is maintained.  By 24 hours, the
hurricane is expected to cross the 26C sea-surface temperature
isotherm while southwesterly wind shear also begins to significantly
increase.  These conditions are expected to lead to rapid weakening
beginning by Thursday afternoon.  The official forecast is above
most of the intensity guidance for the first 24 hours, but is closer
to the consensus aids thereafter.

The initial motion is faster now toward the northwest, or 320/14 kt.
Not much has changed with the track forecast reasoning.  There are
still two camps of models.  The majority of the guidance, including
the GFS, shows Lorena progressing faster and farther east, with
landfall in Baja California Sur followed by a turn toward the
northeast.  But a significant minority of models, including the
ECMWF, CMC, and UKMET, slow down Lorena immediately, with a track
farther west, and then dissipate the system over water without
making landfall.  The steering is such that a stronger cyclone would
be more likely to be in the faster and farther east camp of models.
However, if the hurricane rapidly weakens by Thursday night and
starts to decouple due to the aforementioned increasing
southwesterly shear, then the low-level circulation could
potentially get left behind.  The new NHC forecast shows a faster
forward motion over the next 36 hours with a track slightly to the
right of the previous NHC track.  Due to the rightward shift, the
chance of tropical storm force winds impacting portions of Baja
California Sur is increasing.  Additionally, there is very high
confidence that heavy rainfall amounts leading to significant
flooding will occur in Baja California Sur, especially since the
southwesterly upper-level winds favor deep convection to the right
side of Lorena by late Thursday.  At 48 h and beyond, the new NHC
forecast is similar to, but slightly to the left of, the previous
NHC forecast track.


Key Messages:

1.  Heavy rainfall associated with Tropical Storm Lorena will
continue to impact Baja California Sur, moving into southeastern
Baja California and southwestern Sonora by Thursday, and
contributing to heavy rainfall concerns across Arizona from late
Wednesday through Friday. This will increase the risk of
life-threatening flash floods and mudslides across Mexico,
especially in areas of higher terrain. Isolated to scattered
instances of flash flooding are possible across Arizona through
Friday.

2. The center of Lorena is forecast to move parallel to, but
offshore of, the southwest coast of the Baja Peninsula today, and
then move closer to the west-central coast of the peninsula on
Thursday.  Regardless of the exact track, tropical storm conditions
are likely along portions of the coast of Baja California Sur where
a Tropical Storm Warning has been issued.  Tropical Storm conditions
are also possible through tonight along the southwestern coast of
Baja California Sur where a Tropical Storm Watch is in effect.
Interests elsewhere in Baja California Sur should closely monitor
the latest forecast updates.

3. Life-threatening surf and rip current conditions will affect
portions of the southern and western coasts of Baja California Sur
during the next couple of days.


FORECAST POSITIONS AND MAX WINDS

INIT  03/1500Z 22.3N 111.6W   70 KT  80 MPH
 12H  04/0000Z 23.4N 112.7W   85 KT 100 MPH
 24H  04/1200Z 24.5N 113.7W   80 KT  90 MPH
 36H  05/0000Z 25.6N 113.9W   65 KT  75 MPH
 48H  05/1200Z 26.4N 113.9W   50 KT  60 MPH
 60H  06/0000Z 27.5N 113.5W   40 KT  45 MPH
 72H  06/1200Z 28.4N 112.8W   35 KT  40 MPH
 96H  07/1200Z 30.4N 110.6W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  08/1200Z...DISSIPATED

$$
Forecaster Hagen