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Tropical Storm Rosa Intermediate Advisory Number 23A
NWS National Hurricane Center Miami FL       EP202018
500 PM PDT Sun Sep 30 2018

...ROSA WEAKENS TO A TROPICAL STORM...
...FLOODING RAINS EXPECTED OVER PORTIONS OF NORTHWESTERN MEXICO AND
THE WESTERN UNITED STATES...


SUMMARY OF 500 PM PDT...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...25.6N 118.0W
ABOUT 235 MI...380 KM SW OF PUNTA EUGENIA MEXICO
ABOUT 420 MI...675 KM SSW OF SAN FELIPE MEXICO
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...NNE OR 25 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...985 MB...29.09 INCHES


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

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* West coast of the Baja California peninsula from Punta Abreojos
to Cabo San Quintin

A Tropical Storm Watch is in effect for...
* East coast of the Baja California peninsula from Bahia de los
Angeles to San Felipe

Interests elsewhere in the northern and central Baja California
peninsula and northwestern Sonora should monitor the progress of
Rosa.

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


DISCUSSION AND OUTLOOK
----------------------
At 500 PM PDT (0000 UTC), the center of Tropical Storm Rosa was
located near latitude 25.6 North, longitude 118.0 West.  Rosa is
moving toward the north-northeast near 12 mph (19 km/h).  This
general motion is expected to continue through Tuesday.  On the
forecast track, the center of Rosa will approach the central and
northern Baja California peninsula on Monday.  Rosa's remnants will
then move across the Desert Southwest on Tuesday.

Maximum sustained winds have decreased to near 70 mph (110 km/h)
with higher gusts.  Additional weakening is forecast during the next
couple of days while Rosa approaches and moves over the northern
Baja California peninsula.  Rosa is expected to dissipate over
northwestern Mexico or the southwestern United States by Tuesday.

Tropical-storm-force winds extend outward up to 160 miles (260 km)
from the center.  An automated weather station on Isla Alijos,
located about 180 miles (290 km) off the coast of Baja California
Sur, reported a sustained wind of 49 mph (79 km/h) and a gust to 53
mph (85 km/h) during the past few hours.

The estimated minimum central pressure is 985 mb (29.09 inches).


HAZARDS AFFECTING LAND
----------------------
RAINFALL:  From late Sunday through Wednesday Rosa is expected to
produce the following total rainfall accumulations:

Baja California and northwestern Sonora: 3 to 6 inches, isolated
10 inches.

Central and Southern Arizona: 2 to 4 inches. Isolated 6 inch totals
are possible in the mountains of Central Arizona.

Rest of the Desert Southwest, Central Rockies, and Great Basin:
1 to 2 inches, isolated 4 inches.

These rainfall amounts may produce life-threatening flash flooding.
Dangerous debris flows and landslides are also possible in
mountainous terrain.

WIND:  Tropical storm conditions are expected to first reach the
coast within the warning area by Monday morning.  Tropical storm
conditions are possible within the watch area by late Monday.

SURF:  Swells generated by Rosa will affect portions of the coasts
of southwestern Mexico, most of the west coast of the Baja
California peninsula, and southern California through Tuesday.
These swells are likely to cause life-threatening surf and rip
current conditions.  Please consult products from your
local weather office.


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

$$
Forecaster Berg

NNNN