[Tropical] Hurricane Local Statement

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WTUS86 KSGX 181538
HLSSGX
CAZ043-048-050-055>058-060>062-065-552-554-182345-

Hurricane Hilary Local Statement Advisory Number 9
National Weather Service San Diego CA  EP092023
838 AM PDT Fri Aug 18 2023

This product covers EXTREME SOUTHWESTERN CALIFORNIA

Hilary to produce rare and dangerous flash flooding and tropical
storm-force winds.

NEW INFORMATION
---------------

* CHANGES TO WATCHES AND WARNINGS:
    - A Tropical Storm Watch has been issued for Apple and Lucerne
      Valleys, Coachella Valley, Orange County Coastal Areas, Orange
      County Inland Areas, Riverside County Mountains, San Bernardino
      County Mountains, San Bernardino and Riverside County
      Valleys-The Inland Empire, San Diego County Coastal Areas, San
      Diego County Deserts, San Diego County Mountains, San Diego
      County Valleys, San Gorgonio Pass Near Banning, and Santa Ana
      Mountains and Foothills

* CURRENT WATCHES AND WARNINGS:
    - A Tropical Storm Watch is in effect for Apple and Lucerne
      Valleys, Coachella Valley, Orange County Coastal Areas, Orange
      County Inland Areas, Riverside County Mountains, San Bernardino
      County Mountains, San Bernardino and Riverside County
      Valleys-The Inland Empire, San Diego County Coastal Areas, San
      Diego County Deserts, San Diego County Mountains, San Diego
      County Valleys, San Gorgonio Pass Near Banning, and Santa Ana
      Mountains and Foothills

* STORM INFORMATION:
    - About 1130 miles south-southeast of San Mateo Point CA or about
      1070 miles south-southeast of Mouth of Tijuana River CA
    - 17.9N 111.4W
    - Storm Intensity 145 mph
    - Movement Northwest or 305 degrees at 10 mph

SITUATION OVERVIEW
------------------

Hurricane Hilary will weaken to a tropical storm as it approaches
Southern California this weekend. Flash flooding will be possible
across the whole region, with rare and dangerous flooding possible
across the mountains and deserts. Strong, tropical-storm force winds
will be possible Sunday into Monday.

POTENTIAL IMPACTS
-----------------

* FLOODING RAIN:
Prepare for life-threatening rainfall flooding having possible
devastating impacts across Southern California. Potential impacts
include:
    - Extreme rainfall flooding may prompt numerous evacuations and
      rescues.
    - Rivers and tributaries may overwhelmingly overflow their banks in
      many places with deep moving water. Small streams, creeks,
      canals, and ditches may become raging rivers. In mountain areas,
      deadly runoff may rage down valleys while increasing
      susceptibility to rockslides and mudslides. Flood control systems
      and barriers may become stressed.
    - Flood waters can enter numerous structures within multiple
      communities, some structures becoming uninhabitable or washed
      away. Numerous places where flood waters may cover escape
      routes. Streets and parking lots become rivers of raging water
      with underpasses submerged. Driving conditions become very
      dangerous. Numerous road and bridge closures with some weakened
      or washed out.

Prepare for life-threatening rainfall flooding having possible
extensive impacts across Southern California.

* WIND:
Prepare for dangerous wind having possible significant impacts across
Southern California. Potential impacts in this area include:
    - Some damage to roofing and siding materials, along with damage
      to porches, awnings, carports, and sheds. A few buildings
      experiencing window, door, and garage door failures. Mobile
      homes damaged, especially if unanchored. Unsecured lightweight
      objects become dangerous projectiles.
    - Several large trees snapped or uprooted, but with greater
      numbers in places where trees are shallow rooted. Several
      fences and roadway signs blown over.
    - Some roads impassable from large debris, and more within urban
      or heavily wooded places. Hazardous driving conditions on
      bridges and other elevated roadways.
    - Scattered power and communications outages, but more prevalent
      in areas with above ground lines.

Also, prepare for hazardous wind having possible limited impacts
across Southern California.

* TORNADOES:
Prepare for a tornado event having possible limited impacts across
EXTREME SOUTHWESTERN CALIFORNIA. Potential impacts include:
    - The occurrence of isolated tornadoes can hinder the execution
      of emergency plans during tropical events.
    - A few places may experience tornado damage, along with power
      and communications disruptions.
    - Locations could realize roofs peeled off buildings, chimneys
      toppled, mobile homes pushed off foundations or overturned,
      large tree tops and branches snapped off, shallow-rooted trees
      knocked over, moving vehicles blown off roads, and boats pulled
      from moorings.

* SURGE:
Little to no storm surge impacts are anticipated at this time across
EXTREME SOUTHWESTERN CALIFORNIA.

PRECAUTIONARY/PREPAREDNESS ACTIONS
----------------------------------

* EVACUATIONS:
Listen to local official for recommended preparedness actions,
including possible evacuation. If ordered to evacuate, do so
immediately.


* OTHER PREPAREDNESS INFORMATION:
Now is the time to check your emergency plan and emergency supplies
kit and take necessary actions to protect your family and secure your
home or business.

When making safety and preparedness decisions, do not focus on the
exact forecast track since hazards such as flooding rain, damaging
wind gusts, storm surge, and tornadoes extend well away from the
center of the storm.

If in a place that is vulnerable to high wind, such as near large
trees, a manufactured home, upper floors of a high-rise building, or
on a boat, plan to move to safe shelter.

If you live in a place particularly vulnerable to flooding, such as
near the ocean or a large inland lake, in a low-lying or poor
drainage area, in a valley, or near an already swollen river, plan to
move to safe shelter on higher ground.

Always heed the advice of local officials and comply with orders that
are issued. Do not needlessly jeopardize your life or the lives of
others.

When securing your property, outside preparations should be concluded
as soon as possible before conditions deteriorate. The onset of
strong gusty winds or flooding can cause certain preparedness
activities to become unsafe.

Be sure to let friends and family members know of your intentions for
weathering the storm and your whereabouts. Have someone located away
from the threatened area serve as your point of contact. Share vital
contact information with others. Keep cell phones handy and charged.

Check on those who may not be fully aware of the situation or who are
unable to make personal preparations.

If you are a visitor, know the name of the county in which you are
located and where it is relative to current watches and warnings. If
staying at a hotel, ask the management staff about their onsite
disaster plan. Listen for evacuation orders, especially pertaining to
area visitors.

Closely monitor weather.gov, NOAA Weather Radio and local news
outlets for official storm information. Listen for possible changes
to the forecast.

There is a threat from tornadoes with this storm. Have multiple ways
to receive Tornado Warnings. Be ready to shelter quickly.


* ADDITIONAL SOURCES OF INFORMATION:
- For information on appropriate preparations see ready.gov
- For information on creating an emergency plan see getagameplan.org
- For additional disaster preparedness information see redcross.org

NEXT UPDATE
-----------

The next local statement will be issued by the National Weather
Service in San Diego CA around , or sooner if conditions warrant.

$$

EA
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