墨西哥西南热带风暴“洛雷娜”(12E.Lorena) - 西北行进，趋向下加利福尼亚

ygsj24

000
WTPZ42 KNHC 022059
TCDEP2

Tropical Storm Lorena Discussion Number   4
NWS National Hurricane Center Miami FL       EP122025
Issued by the NWS Weather Prediction Center College Park MD
200 PM MST Tue Sep 02 2025

A 1548z METOP-B ASCAT pass provided solid coverage of Lorena's
overall wind field with also resulted in a northward adjustment to
the initial position.  Since the ASCAT pass, GOES-East visible
imagery continues to show improving overall organization within an
ideal environment for further strengthening.  Symmetric banding
features support Dvorak DT numbers of 3.0 and 3.5 from TAFB and SAB,
respectively. The recent inner core convection bursting with cloud
tops below -80C further suggest a strengthening trend, even without
recent microwave imagery to analyze its inner core structure.  The
initial intensity is set at 45 kt, as a blend of the two operational
Dvorak estimates, along with other objective intensity estimates.

Since the prior advisory, Lorena is moving a bit faster at 13 kt to
the northwest as its being steered by the southwestern periphery of
the larger scale mid-level ridge.  With the small northward
readjustment of position, the northwestward track will continue
through the next 48 hours, but this brings the center and wind field
closer to Baja California compared to the prior track forecast.  As
such, the overall forecast track is a bit faster and shifted north
and east relative to prior forecast, following trends in the latest
track guidance.  Due to the uncertainty that Tropical Storm force
winds may affect areas along the southwestern coasts of Baja
California Sur, the Government of Mexico has issued Tropical Storm
Watches from Cabo San Lucas northward to Cabo San Lazaro.  Any
further deviations north and/or eastward may result in further
expansion of watches and/or warning conditions over the next 24 to
48 hours. Deep layer vertical shear and overall decaying
sea-surface environment will slow the forward speed, with slow
recurvature expected after 48 hours west of Baja California Sur.
The shear results in an expanding track forecast suite, though will
continue to prior trends and overall means recurving the cyclone
toward the central Baja California with initial landfall forecast
after 72 hours.  What remains of the circulation will cross the
Peninsula tracking northeast with a second landfall along coastal
Sonora towards the end of the forecast period.

Lorena is expected to remain fairly small inner core, though with
ample moisture and warm sea-surface temperatures for the next 24 to
36 h, forecasts are for steady intensification toward hurricane
status by Wednesday. There is some potential that Lorena may rapidly
intensify in the short term given its structure and favorable
environment. As Lorena crosses the 26 C isotherm in 2-3 days,
vertical wind shear will also increase and the overall intensity
should start to weaken by late in the week.  As the cyclone turns
northeastward, slow weakening is expected with eventual dissipation
over Sonora by Saturday. The intensity forecast is on the higher
end of the guidance envelope.


Key Messages:

1.  Heavy rainfall associated with Tropical Storm Lorena will begin
to affect Baja California Sur on Wednesday, and southwestern Sonora
by Thursday. This will increase the risk of life-threatening flash
floods and mudslides, especially in areas of higher terrain.

2. Lorena is forecast to approach the Baja California peninsula
later this week. Due to the uncertainty that Tropical Storm force
winds may affect areas along the southwestern coasts of Baja
California Sur, the Government of Mexico has issued Tropical Storm
Watches from Cabo San Lucas northward to Cabo San Lazaro. Residents
should closely monitor the latest forecast updates and ensure that
they have their preparedness plan in place.

FORECAST POSITIONS AND MAX WINDS

INIT  02/2100Z 19.4N 109.0W   45 KT  50 MPH
12H  03/0600Z 20.6N 110.4W   55 KT  65 MPH
24H  03/1800Z 21.8N 112.0W   65 KT  75 MPH
36H  04/0600Z 22.9N 113.1W   75 KT  85 MPH
48H  04/1800Z 24.1N 113.8W   70 KT  80 MPH
60H  05/0600Z 25.1N 113.8W   55 KT  65 MPH
72H  05/1800Z 26.2N 113.3W   45 KT  50 MPH
96H  06/1800Z 28.4N 111.8W   35 KT  40 MPH
120H  07/1800Z 29.9N 110.3W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Gallina/Papin

ygsj24

000
WTPZ32 KNHC 022340
TCPEP2

BULLETIN
Tropical Storm Lorena Intermediate Advisory Number 4A
NWS National Hurricane Center Miami FL       EP122025
500 PM MST Tue Sep 02 2025

...LORENA STRENGTHENING...


SUMMARY OF 500 PM MST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...19.8N 109.2W
ABOUT 220 MI...350 KM SSE OF CABO SAN LUCAS MEXICO
ABOUT 230 MI...370 KM W OF CABO CORRIENTES MEXICO
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...NW OR 315 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Watch is in effect for...
* West Coast of Baja California Sur from Cabo San Lucas northward
to Cabo San Lazaro

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere in southwestern Mexico and the Baja California
peninsula should monitor the progress of this system.  Additional
watches may be required later tonight or on Wednesday.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 500 PM MST (0000 UTC), the center of Tropical Storm Lorena was
located near latitude 19.8 North, longitude 109.2 West. Lorena is
moving toward the northwest near 15 mph (24 km/h), and this motion
with a gradual decrease in forward speed is expected through
Wednesday night.  A generally northward motion, with an additional
decrease in forward speed, is forecast Thursday and Friday.  On the
forecast track, the center of Lorena is likely to move parallel to
the west coast of the Baja California peninsula on Wednesday and
Thursday and then could approach the coast on Friday.

Maximum sustained winds have increased to near 60 mph (95 km/h)
with higher gusts.  Additional strengthening is forecast during the
next 24 hours, and Lorena is expected to become a hurricane by
Wednesday.  Gradual weakening is forecast to begin on Thursday and
continue into the weekend.

Tropical-storm-force winds extend outward up to 35 miles (55 km)
from the center.

The estimated minimum central pressure is 999 mb (29.50 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Lorena can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDEP2 and WMO header WTPZ42 KNHC.

RAINFALL: Areas of heavy rainfall well east and northeast of Lorena
will continue to impact portions of northwestern Mexico from the
states of Colima to Sinaloa today, with isolated flash flooding
possible in areas of mountainous terrain.

Bands of heavy rainfall are expected to begin impacting Baja
California Sur by Wednesday and southwestern Sonora by Thursday,
with this rainfall potentially persisting through Friday.  Rainfall
totals of 4 to 8 inches, with maximum amounts of 12 inches, are
possible across portions of Baja California Sur and southwestern
Sonora through Friday.  Uncertainty remains with these totals, and
locally higher or lower amounts are possible depending on the track
and strength of the system. Potentially significant flash flooding
is a possibility.

WIND:  Tropical storm conditions are possible within the watch
area by late Wednesday into Thursday.


NEXT ADVISORY
-------------
Next complete advisory at 800 PM MST.

$$
Forecaster Berg