Alert archive / California / Excessive Heat Warnings in 2021

Excessive Heat Warning 3, NWS Eureka, CA

July 7, 2021Lake County, Mendocino County, Trinity County, California

NWS Eureka, CA issued this excessive heat warning at Jul 7, 2021, 12:08 PM PDT for Lake County, Mendocino County, Trinity County, California. It took effect at Jul 9, 2021, 12:00 PM PDT. It was in force for 3 days. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 7, 2021, 12:08 PM PDT (19:08 UTC)
In effect from
Jul 9, 2021, 12:00 PM PDT
Expired
Jul 12, 2021, 8:00 PM PDT
In force
3 days
Issued by
NWS Eureka, CA

Counties Lake County, CA, Mendocino County, CA, Trinity County, CA

The radar

The Beale AFB radar (KBBX), 128 km from the middle of the area, began a volume at 19:07 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

Oakland, CA (KOAK), launched 12:00Z, 7.1 hours before the alert went out and 235 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, Oakland, CA at 12:00Z on 2021-07-07Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Oakland, CA at 12:00Z on 2021-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -23 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
1141 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-23 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

648 
WWUS76 KEKA 071908
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1208 PM PDT Wed Jul 7 2021

CAZ107-108-110-111-113>115-080315-
/O.UPG.KEKA.EH.A.0004.210709T1900Z-210712T0700Z/
/O.NEW.KEKA.EH.W.0003.210709T1900Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
1208 PM PDT Wed Jul 7 2021

...EXCESSIVE HEAT WARNING IN EFFECT FROM NOON FRIDAY TO MIDNIGHT
PDT SUNDAY NIGHT...

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

* WHERE...Northern Trinity, Southern Trinity, Northwestern 
  Mendocino Interior, Northeastern Mendocino Interior, 
  Southeastern Mendocino Interior, Northern Lake and Southern 
  Lake Counties.

* WHEN...From noon Friday to midnight PDT Sunday night.

* 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.

&&

$$
18 follow-up statements
831 
WWUS76 KEKA 080301
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
801 PM PDT Wed Jul 7 2021

CAZ107-108-110-111-113>115-081115-
/O.CON.KEKA.EH.W.0003.210709T1900Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
801 PM PDT Wed Jul 7 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT FROM NOON FRIDAY TO
MIDNIGHT PDT SUNDAY NIGHT...

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

* WHERE...Northern Trinity, Southern Trinity, Northwestern 
  Mendocino Interior, Northeastern Mendocino Interior, 
  Southeastern Mendocino Interior, Northern Lake and Southern 
  Lake Counties.

* WHEN...From noon Friday to midnight PDT Sunday night.

* 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.

&&

$$
734 
WWUS76 KEKA 080912
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
212 AM PDT Thu Jul 8 2021

CAZ107-108-110-111-113>115-081715-
/O.CON.KEKA.EH.W.0003.210709T1900Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
212 AM PDT Thu Jul 8 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT FROM NOON FRIDAY TO
MIDNIGHT PDT SUNDAY NIGHT...

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

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino 
  Interior, Northern Lake, Southern Lake and Northern Trinity 
  Counties.

* WHEN...From noon Friday to midnight PDT Sunday night.

* 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.

&&

$$
778 
WWUS76 KEKA 081327
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
627 AM PDT Thu Jul 8 2021

CAZ107-108-110-111-113>115-082130-
/O.CON.KEKA.EH.W.0003.210709T1900Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
627 AM PDT Thu Jul 8 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT FROM NOON FRIDAY TO
MIDNIGHT PDT SUNDAY NIGHT...

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

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino 
  Interior, Northern Lake, Southern Lake and Northern Trinity 
  Counties.

* WHEN...From noon Friday to midnight PDT Sunday night.

* 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.

&&

$$
152 
WWUS76 KEKA 082133
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
233 PM PDT Thu Jul 8 2021

CAZ107-108-110-111-113>115-090545-
/O.CON.KEKA.EH.W.0003.210709T1900Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
233 PM PDT Thu Jul 8 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT FROM NOON FRIDAY TO
MIDNIGHT PDT SUNDAY NIGHT...

* WHAT...Dangerously hot conditions with temperatures up to 111 
  expected.

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino 
  Interior, Northern Lake, Southern Lake and Northern Trinity 
  Counties.

* WHEN...From noon Friday to midnight PDT Sunday night.

* 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.

&&

$$
582 
WWUS76 KEKA 090547
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1047 PM PDT Thu Jul 8 2021

CAZ107-108-110-111-113>115-091400-
/O.CON.KEKA.EH.W.0003.210709T1900Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
1047 PM PDT Thu Jul 8 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT FROM NOON FRIDAY TO
MIDNIGHT SUNDAY NIGHT...

* WHAT...Dangerously hot conditions with temperatures up to 111 
  expected.

* WHERE...Trinity County, Lake County, Southeastern Mendocino 
  Interior, Northwestern Mendocino Interior, Northeastern 
  Mendocino Interior.

* WHEN...From noon Friday to midnight Sunday night.

* 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, schedule 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.

$$
491 
WWUS76 KEKA 091034
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
334 AM PDT Fri Jul 9 2021

CAZ107-108-110-111-113>115-091845-
/O.CON.KEKA.EH.W.0003.210709T1900Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
334 AM PDT Fri Jul 9 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT FROM NOON TODAY TO
MIDNIGHT PDT SUNDAY NIGHT...

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

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino 
  Interior, Northern Lake, Southern Lake and Northern Trinity 
  Counties.

* WHEN...From noon today to midnight PDT Sunday night.

* 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.

&&

$$
697 
WWUS76 KEKA 091831
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1131 AM PDT Fri Jul 9 2021

CAZ107-108-110-111-113>115-100245-
/O.CON.KEKA.EH.W.0003.210709T1900Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
1131 AM PDT Fri Jul 9 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL MIDNIGHT PDT
SUNDAY NIGHT...

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

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino 
  Interior, Northern Lake, Southern Lake and Northern Trinity 
  Counties.

* WHEN...Until midnight PDT Sunday night.

* 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.

&&

$$
793 
WWUS76 KEKA 100344
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
844 PM PDT Fri Jul 9 2021

CAZ107-108-110-111-113>115-101215-
/O.CON.KEKA.EH.W.0003.000000T0000Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
844 PM PDT Fri Jul 9 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL MIDNIGHT PDT
SUNDAY NIGHT...

* WHAT...Dangerously hot conditions with temperatures up to 111.

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino 
  Interior, Northern Lake, Southern Lake and Northern Trinity 
  Counties.

* WHEN...Until midnight PDT Sunday night.

* 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.

&&

$$
060 
WWUS76 KEKA 101027
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
327 AM PDT Sat Jul 10 2021

CAZ107-108-110-111-113>115-101830-
/O.CON.KEKA.EH.W.0003.000000T0000Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
327 AM PDT Sat Jul 10 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL MIDNIGHT PDT
SUNDAY NIGHT...

* WHAT...Dangerously hot conditions with temperatures up to 111.

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino 
  Interior, Northern Lake, Southern Lake and Northern Trinity 
  Counties.

* WHEN...Until midnight PDT Sunday night.

* 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.

&&

$$
217 
WWUS76 KEKA 101829
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1129 AM PDT Sat Jul 10 2021

CAZ107-108-110-111-113>115-110230-
/O.CON.KEKA.EH.W.0003.000000T0000Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
1129 AM PDT Sat Jul 10 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL MIDNIGHT PDT
SUNDAY NIGHT...

* WHAT...Dangerously hot conditions with temperatures up to 111.

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino 
  Interior, Northern Lake, Southern Lake and Northern Trinity 
  Counties.

* WHEN...Until midnight PDT Sunday night.

* 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.

&&

$$
013 
WWUS76 KEKA 110215
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
715 PM PDT Sat Jul 10 2021

CAZ107-108-110-111-113>115-111100-
/O.CON.KEKA.EH.W.0003.000000T0000Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
715 PM PDT Sat Jul 10 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL MIDNIGHT PDT
SUNDAY NIGHT...

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

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino 
  Interior, Northern Lake, Southern Lake and Northern Trinity 
  Counties.

* WHEN...Until midnight PDT Sunday night.

* 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.

&&

$$
286 
WWUS76 KEKA 111016
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
316 AM PDT Sun Jul 11 2021

CAZ107-108-110-111-113>115-111830-
/O.CON.KEKA.EH.W.0003.000000T0000Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
316 AM PDT Sun Jul 11 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL MIDNIGHT PDT
TONIGHT...

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

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino 
  Interior, Northern Lake, Southern Lake and Northern Trinity 
  Counties.

* WHEN...Until midnight PDT tonight.

* 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.

&&

$$
232 
WWUS76 KEKA 111814
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1114 AM PDT Sun Jul 11 2021

CAZ107-108-110-111-113>115-120215-
/O.CON.KEKA.EH.W.0003.000000T0000Z-210712T0700Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Southeastern Mendocino Interior-
Northern Lake-Southern Lake-
1114 AM PDT Sun Jul 11 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL MIDNIGHT PDT
TONIGHT...

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

* WHERE...Southern Trinity, Southeastern Mendocino Interior, 
  Northwestern Mendocino Interior, Northeastern Mendocino 
  Interior, Northern Lake, Southern Lake and Northern Trinity 
  Counties.

* WHEN...Until midnight PDT tonight.

* 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.

&&

$$
578 
WWUS76 KEKA 120211
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
711 PM PDT Sun Jul 11 2021

CAZ107-108-111-114-115-121200-
/O.EXT.KEKA.EH.W.0003.000000T0000Z-210713T0300Z/
Northern Trinity-Southern Trinity-Northeastern Mendocino Interior-
Northern Lake-Southern Lake-
711 PM PDT Sun Jul 11 2021

...EXCESSIVE HEAT WARNING NOW IN EFFECT UNTIL 8 PM PDT MONDAY...

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

* WHERE...Southern Trinity, Northeastern Mendocino Interior, 
  Northern Lake, Southern Lake and Northern Trinity Counties.

* WHEN...Until 8 PM PDT Monday.

* 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.

&&

$$

CAZ110-113-120700-
/O.CON.KEKA.EH.W.0003.000000T0000Z-210712T0700Z/
Northwestern Mendocino Interior-Southeastern Mendocino Interior-
711 PM PDT Sun Jul 11 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL MIDNIGHT PDT
TONIGHT...

* WHAT...Hot conditions through this evening.

* WHERE...Southeastern Mendocino Interior and Northwestern 
  Mendocino Interior Counties.

* WHEN...Until midnight PDT tonight.

* 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.

&&

$$
112 
WWUS76 KEKA 120646
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1146 PM PDT Sun Jul 11 2021

CAZ110-113-120800-
/O.EXP.KEKA.EH.W.0003.000000T0000Z-210712T0700Z/
Northwestern Mendocino Interior-Southeastern Mendocino Interior-
1146 PM PDT Sun Jul 11 2021

...EXCESSIVE HEAT WARNING WILL EXPIRE AT MIDNIGHT PDT TONIGHT...

$$

CAZ107-108-111-114-115-121500-
/O.CON.KEKA.EH.W.0003.000000T0000Z-210713T0300Z/
Northern Trinity-Southern Trinity-Northeastern Mendocino Interior-
Northern Lake-Southern Lake-
1146 PM PDT Sun Jul 11 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 8 PM PDT
MONDAY...

* WHAT...Dangerously hot conditions with temperatures up to 106.

* WHERE...Southern Trinity, Northeastern Mendocino Interior, 
  Northern Lake, Southern Lake and Northern Trinity Counties.

* WHEN...Until 8 PM PDT Monday.

* 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.

&&

$$
151 
WWUS76 KEKA 121029
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
329 AM PDT Mon Jul 12 2021

CAZ107-108-111-114-115-121830-
/O.CON.KEKA.EH.W.0003.000000T0000Z-210713T0300Z/
Northern Trinity-Southern Trinity-Northeastern Mendocino Interior-
Northern Lake-Southern Lake-
329 AM PDT Mon Jul 12 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 8 PM PDT THIS
EVENING...

* WHAT...Dangerously hot conditions with temperatures up to 106.

* WHERE...Southern Trinity, Northeastern Mendocino Interior, 
  Northern Trinity, Northern Lake and Southern Lake Counties.

* WHEN...Until 8 PM PDT this evening.

* 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.

&&

$$
905 
WWUS76 KEKA 121820
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1120 AM PDT Mon Jul 12 2021

CAZ107-108-111-114-115-130230-
/O.CON.KEKA.EH.W.0003.000000T0000Z-210713T0300Z/
Northern Trinity-Southern Trinity-Northeastern Mendocino Interior-
Northern Lake-Southern Lake-
1120 AM PDT Mon Jul 12 2021

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 8 PM PDT THIS
EVENING...

* WHAT...Dangerously hot conditions with temperatures up to 106.

* WHERE...Southern Trinity, Northeastern Mendocino Interior, 
  Northern Trinity, Northern Lake and Southern Lake Counties.

* WHEN...Until 8 PM PDT this evening.

* 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.

&&

$$
925 
WWUS76 KEKA 130235
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
735 PM PDT Mon Jul 12 2021

CAZ107-108-111-114-115-130345-
/O.EXP.KEKA.EH.W.0003.000000T0000Z-210713T0300Z/
Northern Trinity-Southern Trinity-Northeastern Mendocino Interior-
Northern Lake-Southern Lake-
735 PM PDT Mon Jul 12 2021

...EXCESSIVE HEAT WARNING WILL EXPIRE AT 8 PM PDT THIS EVENING...

$$

The office that day

Everything else NWS Eureka, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 6, 8:58 PM PDTSmall Craft AdvisoryEKA21 days

Nearby

Excessive Heat Warnings in California, 2021Every excessive heat warning 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.