Alert archive / California / Heat Advisories in 2021

Heat Advisory 2, NWS Los Angeles, CA

June 17, 2021Los Angeles County, California

NWS Los Angeles, CA issued this heat advisory at Jun 17, 2021, 9:05 PM PDT for Los Angeles County, California. It was in force for 48 hr.

The area

The counties it named.

The facts

Issued
Jun 17, 2021, 9:05 PM PDT (04:05 UTC)
Expired
Jun 19, 2021, 9:00 PM PDT
In force
48 hr
Issued by
NWS Los Angeles, CA

County Los Angeles County, CA

The radar

The Santa Ana Mts radar (KSOX), 71 km from the middle of the area, began a volume at 04:07 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 4.1 hours before the alert went out and 184 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, San Diego, CA at 00:00Z on 2021-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 00:00Z on 2021-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -30 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2583 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-30 m²/s²
0-3 km storm-relative helicity
18 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

190 
WWUS76 KLOX 180405
NPWLOX

URGENT - WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
905 PM PDT Thu Jun 17 2021

CAZ088-181215-
/O.EXP.KLOX.EH.W.0001.000000T0000Z-210618T0400Z/
/O.NEW.KLOX.HT.Y.0002.210618T0405Z-210619T0400Z/
Santa Clarita Valley-
Including the cities of Santa Clarita, Newhall, and Valencia
905 PM PDT Thu Jun 17 2021

...HEAT ADVISORY IN EFFECT UNTIL 9 PM PDT FRIDAY...
...EXCESSIVE HEAT WARNING HAS EXPIRED...

* WHAT...Temperatures up to around 100 degrees.

* WHERE...Santa Clarita Valley.

* WHEN...Until 9 PM PDT Friday.

* IMPACTS...Hot temperatures may cause heat illnesses to occur.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ036-044>046-547-548-180515-
/O.EXP.KLOX.HT.Y.0001.000000T0000Z-210618T0400Z/
Santa Ynez Valley-Ventura County Interior Valleys-
Ventura County Coastal Valleys-
Santa Monica Mountains Recreational Area-
Los Angeles County San Fernando Valley-
Los Angeles County San Gabriel Valley-
Including the cities of Solvang, Santa Ynez, Santa Paula, 
Fillmore, Ojai, Piru, Thousand Oaks, Simi Valley, Moorpark, 
Newbury Park, Woodland Hills, Northridge, Burbank, 
Universal City, Pasadena, San Gabriel, and Pomona
905 PM PDT Thu Jun 17 2021

...HEAT ADVISORY HAS EXPIRED...

Cooler temperatures are forecast to occur over the coming days and
the heat advisory will be allowed to expire.

$$

CAZ052>054-181215-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
Santa Barbara County Mountains-Ventura County Mountains-
Los Angeles County Mountains excluding the Santa Monica Range-
Including the cities of San Marcos Pass, 
San Rafael Wilderness Area, Dick Smith Wilderness Area, 
Lockwood Valley, Mount Pinos, Acton, Mount Wilson, and Sandberg
905 PM PDT Thu Jun 17 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SATURDAY...

* WHAT...Dangerously hot conditions with temperatures up to 110.

* WHERE...Los Angeles, Ventura and Santa Barbara County 
  Mountains.

* WHEN...Until 9 PM PDT Saturday.

* IMPACTS...Extreme heat will significantly increase the potential
  for heat related illnesses, particularly for those working or
  participating in outdoor activities.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ059-181215-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
Antelope Valley-
Including the cities of Lancaster and Palmdale
905 PM PDT Thu Jun 17 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SATURDAY...

* WHAT...Dangerously hot conditions with temperatures up to 113.

* WHERE...Antelope Valley.

* WHEN...Until 9 PM PDT Saturday.

* IMPACTS...Extreme heat will significantly increase the potential
  for heat related illnesses, particularly for those working or
  participating in outdoor activities.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ037-038-051-181215-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
San Luis Obispo County Interior Valleys-Cuyama Valley-
San Luis Obispo County Mountains-
Including the cities of Paso Robles, Atascadero, Cuyama, 
and Black Mountain
905 PM PDT Thu Jun 17 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SATURDAY...

* WHAT...Dangerously hot conditions with temperatures up to 108.

* WHERE...San Luis Obispo County Interior Valleys, Cuyama Valley 
  and San Luis Obispo County Mountains.

* WHEN...Until 9 PM PDT Saturday.

* IMPACTS...Extreme heat will significantly increase the potential
  for heat related illnesses, particularly for those working or
  participating in outdoor activities.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

Hall
6 follow-up statements
004 
WWUS76 KLOX 181005
NPWLOX

URGENT - WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
305 AM PDT Fri Jun 18 2021

CAZ052>054-182200-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
Santa Barbara County Mountains-Ventura County Mountains-
Los Angeles County Mountains excluding the Santa Monica Range-
Including the cities of San Marcos Pass, 
San Rafael Wilderness Area, Dick Smith Wilderness Area, 
Lockwood Valley, Mount Pinos, Acton, Mount Wilson, and Sandberg
305 AM PDT Fri Jun 18 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SATURDAY...

* WHAT...Dangerously hot conditions with temperatures up to 109.

* WHERE...Los Angeles, Ventura and Santa Barbara County 
  Mountains.

* WHEN...Until 9 PM PDT Saturday.

* IMPACTS...Extreme heat will significantly increase the 
  potential for heat related illnesses, particularly for those 
  working or participating in outdoor activities.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ059-182200-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
Antelope Valley-
Including the cities of Lancaster and Palmdale
305 AM PDT Fri Jun 18 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SATURDAY...

* WHAT...Dangerously hot conditions with temperatures up to 112.

* WHERE...Antelope Valley.

* WHEN...Until 9 PM PDT Saturday.

* IMPACTS...Extreme heat will significantly increase the 
  potential for heat related illnesses, particularly for those 
  working or participating in outdoor activities.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ037-038-051-182200-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
San Luis Obispo County Interior Valleys-Cuyama Valley-
San Luis Obispo County Mountains-
Including the cities of Paso Robles, Atascadero, Cuyama, 
and Black Mountain
305 AM PDT Fri Jun 18 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SATURDAY...

* WHAT...Dangerously hot conditions with temperatures up to 107.

* WHERE...San Luis Obispo County Interior Valleys, Cuyama Valley 
  and San Luis Obispo County Mountains.

* WHEN...Until 9 PM PDT Saturday.

* IMPACTS...Extreme heat will significantly increase the 
  potential for heat related illnesses, particularly for those 
  working or participating in outdoor activities.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ088-182200-
/O.CON.KLOX.HT.Y.0002.000000T0000Z-210619T0400Z/
Santa Clarita Valley-
Including the cities of Santa Clarita, Newhall, and Valencia
305 AM PDT Fri Jun 18 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM PDT THIS EVENING...

* WHAT...Temperatures up to around 101 degrees.

* WHERE...Santa Clarita Valley.

* WHEN...Until 9 PM PDT this evening.

* IMPACTS...Hot temperatures may cause heat illnesses to occur.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

Kaplan/ASR
795 
WWUS76 KLOX 181556
NPWLOX

URGENT - WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
856 AM PDT Fri Jun 18 2021

CAZ037-038-051>054-190000-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
San Luis Obispo County Interior Valleys-Cuyama Valley-
San Luis Obispo County Mountains-Santa Barbara County Mountains-
Ventura County Mountains-
Los Angeles County Mountains excluding the Santa Monica Range-
Including the cities of Paso Robles, Atascadero, Cuyama, 
Black Mountain, San Marcos Pass, San Rafael Wilderness Area, 
Dick Smith Wilderness Area, Lockwood Valley, Mount Pinos, Acton, 
Mount Wilson, and Sandberg
856 AM PDT Fri Jun 18 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SATURDAY...

* WHAT...Dangerously hot conditions with daily high temperatures
  between 98 and 108 common and very warm nights.

* WHERE...The mountains and interior valleys of Los Angeles,
  Ventura and Santa Barbara, and San Luis Obispo Counties.

* WHEN...Until 9 PM PDT Saturday.

* IMPACTS...Extreme heat will significantly increase the potential
  for heat related illnesses for anyone, especially for sensitive
  populations including the very young, the very old, and active
  outdoors for many hours.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ059-190000-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
Antelope Valley-
Including the cities of Lancaster and Palmdale
856 AM PDT Fri Jun 18 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SATURDAY...

* WHAT...Dangerously hot conditions with daily high temperatures
  between 104 and 112 common and very warm nights.

* WHERE...Antelope Valley.

* WHEN...Until 9 PM PDT Saturday.

* IMPACTS...Extreme heat will significantly increase the potential
  for heat related illnesses for anyone, especially for sensitive
  populations including the very young, the very old, and active
  outdoors for many hours.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ088-190000-
/O.EXT.KLOX.HT.Y.0002.000000T0000Z-210620T0400Z/
Santa Clarita Valley-
Including the cities of Santa Clarita, Newhall, and Valencia
856 AM PDT Fri Jun 18 2021

...HEAT ADVISORY NOW IN EFFECT UNTIL 9 PM PDT SATURDAY...

* WHAT...Daily high temperatures between 96 and 102 common.

* WHERE...Santa Clarita Valley.

* WHEN...Until 9 PM PDT Saturday.

* IMPACTS...Persistently hot conditions will increase the risk for
  heat-related illness for sensitive populations including the 
  very young, the very old, and those active outdoors for many 
  hours.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$
929 
WWUS76 KLOX 182043
NPWLOX

URGENT - WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
143 PM PDT Fri Jun 18 2021

CAZ059-191300-
/O.EXT.KLOX.EH.W.0001.000000T0000Z-210621T0400Z/
Antelope Valley-
Including the cities of Lancaster and Palmdale
143 PM PDT Fri Jun 18 2021

...EXCESSIVE HEAT WARNING NOW IN EFFECT UNTIL 9 PM PDT SUNDAY...

* WHAT...Dangerously hot conditions with daily high temperatures 
  between 103 and 111 common and very warm nights.

* WHERE...Antelope Valley.

* WHEN...Until 9 PM PDT Sunday, hottest through Saturday.

* IMPACTS...Extreme heat will significantly increase the risk for
  heat related illnesses for anyone, especially for sensitive 
  populations including the very young, the very old, and active 
  outdoors for many hours.

* ADDITIONAL DETAILS...This warning was extended through Sunday.
  Much improved conditions expected Monday through Wednesday.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ037-038-051>054-191300-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
San Luis Obispo County Interior Valleys-Cuyama Valley-
San Luis Obispo County Mountains-Santa Barbara County Mountains-
Ventura County Mountains-
Los Angeles County Mountains excluding the Santa Monica Range-
Including the cities of Paso Robles, Atascadero, Cuyama, 
Black Mountain, San Marcos Pass, San Rafael Wilderness Area, 
Dick Smith Wilderness Area, Lockwood Valley, Mount Pinos, Acton, 
Mount Wilson, and Sandberg
143 PM PDT Fri Jun 18 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SATURDAY...

* WHAT...Dangerously hot conditions with daily high temperatures 
  between 97 and 107 common and very warm nights.

* WHERE...The mountains and interior valleys of Los Angeles, 
  Ventura and Santa Barbara, and San Luis Obispo Counties.

* WHEN...Until 9 PM PDT Saturday.

* IMPACTS...Extreme heat will significantly increase the risk for
  heat-related illnesses for anyone, especially for sensitive 
  populations including the very young, the very old, and active 
  outdoors for many hours.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ088-191300-
/O.CON.KLOX.HT.Y.0002.000000T0000Z-210620T0400Z/
Santa Clarita Valley-
Including the cities of Santa Clarita, Newhall, and Valencia
143 PM PDT Fri Jun 18 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM PDT SATURDAY...

* WHAT...Daily high temperatures between 96 and 102 common.

* WHERE...Santa Clarita Valley.

* WHEN...Until 9 PM PDT Saturday.

* IMPACTS...Persistently hot conditions will increase the risk 
  for heat-related illness for sensitive populations including 
  the very young, the very old, and those active outdoors for 
  many hours.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$
573 
WWUS76 KLOX 191021
NPWLOX

URGENT - WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
321 AM PDT Sat Jun 19 2021

CAZ037-038-051>054-192230-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
San Luis Obispo County Interior Valleys-Cuyama Valley-
San Luis Obispo County Mountains-Santa Barbara County Mountains-
Ventura County Mountains-
Los Angeles County Mountains excluding the Santa Monica Range-
Including the cities of Paso Robles, Atascadero, Cuyama, 
Black Mountain, San Marcos Pass, San Rafael Wilderness Area, 
Dick Smith Wilderness Area, Lockwood Valley, Mount Pinos, Acton, 
Mount Wilson, and Sandberg
321 AM PDT Sat Jun 19 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT THIS
EVENING...

* WHAT...Dangerously hot conditions with daily high temperatures 
  between 97 and 107 common and very warm nights.

* WHERE...The mountains and interior valleys of Los Angeles, 
  Ventura and Santa Barbara, and San Luis Obispo Counties.

* WHEN...Until 9 PM PDT this evening.

* IMPACTS...Extreme heat will significantly increase the risk for
  heat-related illnesses for anyone, especially for sensitive
  populations including the very young, the very old, and active
  outdoors for many hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ059-192230-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210621T0400Z/
Antelope Valley-
Including the cities of Lancaster and Palmdale
321 AM PDT Sat Jun 19 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SUNDAY...

* WHAT...Dangerously hot conditions with daily high temperatures 
  between 103 and 111 common and very warm nights.

* WHERE...Antelope Valley.

* WHEN...Until 9 PM PDT Sunday.

* IMPACTS...Extreme heat will significantly increase the risk 
  for heat related illnesses for anyone, especially for 
  sensitive populations including the very young, the very old, 
  and active outdoors for many hours.

* ADDITIONAL DETAILS...This warning was extended through Sunday.
  Cooler conditions expected Monday through Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ088-192230-
/O.CON.KLOX.HT.Y.0002.000000T0000Z-210620T0400Z/
Santa Clarita Valley-
Including the cities of Santa Clarita, Newhall, and Valencia
321 AM PDT Sat Jun 19 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM PDT THIS EVENING...

* WHAT...Daily high temperatures between 96 and 102 common.

* WHERE...Santa Clarita Valley.

* WHEN...Until 9 PM PDT this evening.

* IMPACTS...Persistently hot conditions will increase the risk for
  heat-related illness for sensitive populations including the
  very young, the very old, and those active outdoors for many
  hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

Rorke
769 
WWUS76 KLOX 192219
NPWLOX

URGENT - WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
319 PM PDT Sat Jun 19 2021

CAZ037-038-051>054-200400-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
San Luis Obispo County Interior Valleys-Cuyama Valley-
San Luis Obispo County Mountains-Santa Barbara County Mountains-
Ventura County Mountains-
Los Angeles County Mountains excluding the Santa Monica Range-
Including the cities of Paso Robles, Atascadero, Cuyama, 
Black Mountain, San Marcos Pass, San Rafael Wilderness Area, 
Dick Smith Wilderness Area, Lockwood Valley, Mount Pinos, Acton, 
Mount Wilson, and Sandberg
319 PM PDT Sat Jun 19 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT THIS
EVENING...

* WHAT...Dangerously hot conditions with daily high temperatures 
  between 97 and 107 degrees common and very warm nights.

* WHERE...The mountains and interior valleys of Los Angeles, 
  Ventura and Santa Barbara, and San Luis Obispo Counties.

* WHEN...Until 9 PM PDT this evening.

* IMPACTS...Extreme heat will significantly increase the risk for
  heat-related illnesses for anyone, especially for sensitive
  populations including the very young, the very old, and active
  outdoors for many hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ059-200630-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210621T0400Z/
Antelope Valley-
Including the cities of Lancaster and Palmdale
319 PM PDT Sat Jun 19 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SUNDAY...

* WHAT...Dangerously hot conditions with daily high temperatures 
  between 103 and 111 degrees common and very warm nights.

* WHERE...Antelope Valley.

* WHEN...Until 9 PM PDT Sunday.

* IMPACTS...Extreme heat will significantly increase the risk 
  for heat related illnesses for anyone, especially for 
  sensitive populations including the very young, the very old, 
  and active outdoors for many hours.

* ADDITIONAL DETAILS...Cooler conditions expected Monday through 
  Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ088-200400-
/O.CON.KLOX.HT.Y.0002.000000T0000Z-210620T0400Z/
Santa Clarita Valley-
Including the cities of Santa Clarita, Newhall, and Valencia
319 PM PDT Sat Jun 19 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM PDT THIS EVENING...

* WHAT...Daily high temperatures between 96 and 102 degrees 
  common.

* WHERE...Santa Clarita Valley.

* WHEN...Until 9 PM PDT this evening.

* IMPACTS...Persistently hot conditions will increase the risk for
  heat-related illness for sensitive populations including the
  very young, the very old, and those active outdoors for many
  hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

Hall
739 
WWUS76 KLOX 200354
NPWLOX

URGENT - WEATHER MESSAGE
National Weather Service Los Angeles/Oxnard CA
854 PM PDT Sat Jun 19 2021

CAZ037-038-051>054-200500-
/O.EXP.KLOX.EH.W.0001.000000T0000Z-210620T0400Z/
San Luis Obispo County Interior Valleys-Cuyama Valley-
San Luis Obispo County Mountains-Santa Barbara County Mountains-
Ventura County Mountains-
Los Angeles County Mountains excluding the Santa Monica Range-
Including the cities of Paso Robles, Atascadero, Cuyama, 
Black Mountain, San Marcos Pass, San Rafael Wilderness Area, 
Dick Smith Wilderness Area, Lockwood Valley, Mount Pinos, Acton, 
Mount Wilson, and Sandberg
854 PM PDT Sat Jun 19 2021

...EXCESSIVE HEAT WARNING WILL EXPIRE AT 9 PM PDT THIS EVENING...

Conditions will continue to cool on Sunday and the Excessive Heat
Warning will be allowed to expire.

$$

CAZ088-200500-
/O.EXP.KLOX.HT.Y.0002.000000T0000Z-210620T0400Z/
Santa Clarita Valley-
Including the cities of Santa Clarita, Newhall, and Valencia
854 PM PDT Sat Jun 19 2021

...HEAT ADVISORY WILL EXPIRE AT 9 PM PDT THIS EVENING...

Conditions will continue to cool on Sunday and the Heat Advisory 
will be allowed to expire.

$$

CAZ059-201200-
/O.CON.KLOX.EH.W.0001.000000T0000Z-210621T0400Z/
Antelope Valley-
Including the cities of Lancaster and Palmdale
854 PM PDT Sat Jun 19 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM PDT
SUNDAY...

* WHAT...Dangerously hot conditions with daily high temperatures 
  between 103 and 111 degrees common and very warm nights.

* WHERE...Antelope Valley.

* WHEN...Until 9 PM PDT Sunday.

* IMPACTS...Extreme heat will significantly increase the risk 
  for heat related illnesses for anyone, especially for 
  sensitive populations including the very young, the very old, 
  and active outdoors for many hours.

* ADDITIONAL DETAILS...Cooler conditions expected Monday through 
  Wednesday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

Hall

What forecasters said that day

The local office's own words before this heat advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Los Angeles, CA wrote its last area forecast discussion before this heat advisory went out at Jun 17, 1:38 PM PDT, 7 hours 27 minutes earlier.

Area forecast discussion, Jun 17, 1:38 PM PDT, 7 hours 27 minutes before
Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
138 PM PDT Thu Jun 17 2021

.SYNOPSIS...17/130 PM.

High pressure aloft will continue to dominate the weather pattern
across southwest California through Saturday. Hot conditions will
continue during this time across interior areas. Areas of low
clouds will be confined to the coast. A cooling trend is expected
over the weekend and into early next week with more extensive
night through morning low clouds and fog.

&&

.SHORT TERM (TDY-SUN)...17/136 PM.

Thunderstorms that rolled through LA County this morning are long
gone, however the air mass remains somewhat unstable. LI's are
around -4 and lapse rates are 9-10C however, CAPE's are relatively
low and bases would be really high anyway. So while chances
aren't zero for additional thunderstorm activity over the
mountains the rest of the day they aren't high enough to include
in the forecast.

For the rest of the forecast not much change. Temperature trends
today were quite variable, running from much cooler along the
Central Coast (by as much as 40 degrees in Morro Bay) to similar
or slightly warmer across the LA/Ventura County coast/valleys.
Today will be the last heat advisory day for the coastal valleys
but interior areas will stick with heat warnings through Saturday.

Marine layer stratus has stuck around the coastal waters and some
beaches this afternoon and is also starting to push to the north
around Pt Conception as a modest southerly surge develops. Low
clouds should spread up through coastal SLO county by early
Friday. It's still very shallow so inland push should be minimal,
but areas of dense fog possible near the coast.

Slow cooling trend expected through the weekend. Low clouds
expected to remain confined to coastal zones as high pressure
should keep it squashed below 1000' or so.

.LONG TERM (MON-THU)...17/128 PM.

A trough moving into northern California early next week will help
increase onshore flow and bring temps back to normal or even a few
degrees below normal in some areas. Marine layer stratus expected
to push into the valleys as soon as Monday and be a regular night
and morning feature there. Coastal areas will struggle to clear
each day, so overall very typical June conditions. Dry southwest
flow aloft will return and bring back drier conditions and push
the tropical moisture back to the southeast. Overall a pretty
quiet week of weather.

&&

.AVIATION...17/1720Z.

At 1630Z, the marine inversion at KLAX was based at 1000 feet.
The top of the inversion was 4200 feet with a temperature of
31 degrees Celsius.

Overall, moderate to high confidence in 18Z TAF package. Current
CIG/VSBY restrictions will clear coastal sites by 20Z with VFR
conditions for all areas this afternoon. For this evening and
overnight, high confidence in return of CIG/VSBY restrictions to
all coastal sites, but low to moderate confidence in timing and
flight category.

KLAX...Moderate confidence in 18Z TAF. High confidence in VFR
conditions through this afternoon. For this evening and overnight,
high confidence in return of CIG/VSBY restrictions, but low
confidence in timing (could be +/- 4 hours of current 03Z
forecast) and flight category (could range from IFR to VLIFR). No
significant easterly wind component is expected.

KBUR...High confidence in 18Z TAF as VFR conditions are
anticipated through the period. Thunderstorms will continue to
move near the airfield through 20z.

&&

.MARINE...17/1206 PM.

For the Outer Waters, moderate to high confidence in current
forecast. High confidence in winds and seas remaining below Small
Craft Advisory (SCA) levels through Saturday. For Sunday through
Tuesday, there is a 30% chance of SCA level winds.

For the Inner Waters north of Point Sal, high confidence in
current forecast. Today through Tuesday, winds and seas are
expected to remain below SCA levels.

For the Inner Waters south of Point Conception, high confidence in
current forecast. Today through Tuesday, winds and seas are
expected to remain below SCA levels.

Patchy dense fog will continue to impact the coastal waters south
of Point Conception through this afternoon.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory in effect until 9 PM PDT this evening for zones
      36-44>46-547. (See LAXNPWLOX).
     Excessive Heat Warning in effect until 9 PM PDT Saturday for
      zones 37-38-51>54-59. (See LAXNPWLOX).
     Excessive Heat Warning in effect until 9 PM PDT this evening
      for zone 88. (See LAXNPWLOX).
PZ...NONE.

&&

.HAZARD POTENTIAL OUTLOOK (SUN-THU).

No significant hazards expected.

&&

PUBLIC...MW
AVIATION...RAT
MARINE...RAT
SYNOPSIS...MW

weather.gov/losangeles

Nearby

Heat Advisories in California, 2021Every heat advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.