Alert archive / California / Flash Flood Watches in 2023

Flash Flood Watch 3, NWS Eureka, CA

August 30, 2023Del Norte County, Humboldt County, California

NWS Eureka, CA issued this flash flood watch at Aug 30, 2023, 10:51 AM PDT for Del Norte County, Humboldt County, California. It took effect at Sep 1, 2023, 8:00 AM PDT. It was in force for 13 hr.

The area

The counties it named.

The facts

Issued
Aug 30, 2023, 10:51 AM PDT (17:51 UTC)
In effect from
Sep 1, 2023, 8:00 AM PDT
Expired
Sep 1, 2023, 9:25 PM PDT
In force
13 hr
Issued by
NWS Eureka, CA
Flood severity
None

Counties Del Norte County, CA, Humboldt County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 86 km from the middle of the area, began a volume at 17:52 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

Medford/Jackson, OR (KMFR), launched 12:00Z, 5.9 hours before the alert went out and 158 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, Medford/Jackson, OR at 12:00Z on 2023-08-30Temperature 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, Medford/Jackson, OR at 12:00Z on 2023-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 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
1036 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
-22 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

516 
WGUS66 KEKA 301751
FFAEKA

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Eureka CA
1051 AM PDT Wed Aug 30 2023

.An upper disturbance will yield a period of late summer rainfall 
across Trinity County during Friday. Heavier showers and embedded 
thunderstorms combined with slow storm motions will result in a 
threat for locally heavy rainfall across the River Complex burn 
scar. The threat for debris flows will exist, particularly across 
Coffee Creek.

CAZ107-310200-
/O.NEW.KEKA.FF.A.0003.230901T1500Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-
1051 AM PDT Wed Aug 30 2023

...FLASH FLOOD WATCH FOR THE RIVER COMPLEX BURN SCAR IN EFFECT FROM 
FRIDAY MORNING THROUGH FRIDAY EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall are possible over the River Complex burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Northern Trinity.

* WHEN...From Friday morning through Friday evening.

* IMPACTS...Heavy rainfall over the River Complex burn scar near an 
  inch per hour will be possible up to and during the period of the 
  watch. The threat for debris flows due to heavy rainfall will be 
  highest across Coffee Creek. Be sure to stay up to date with 
  information from local authorities. Heavy rainfall could trigger 
  flash flooding of low-lying areas, urbanized street flooding, and 
  debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the River Complex burn scar, which may lead to
    flash flooding and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JMG
10 follow-up statements
161 
WGUS66 KEKA 302117
FFAEKA

Flood Watch
National Weather Service Eureka CA
217 PM PDT Wed Aug 30 2023

CAZ107-310530-
/O.CON.KEKA.FF.A.0003.230901T1500Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-
217 PM PDT Wed Aug 30 2023

...FLASH FLOOD WATCH FOR THE RIVER COMPLEX BURN SCAR REMAINS IN 
EFFECT FROM FRIDAY MORNING THROUGH FRIDAY EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the River Complex burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Northern Trinity.

* WHEN...From Friday morning through Friday evening.

* IMPACTS...Heavy rainfall over the River Complex burn scar with 
  precipitation rates near an inch per hour will be possible during 
  the period of the watch. The threat for debris flows due to heavy 
  rainfall will be highest across the Coffee Creek drainage basin. 
  Be sure to stay up to date with information from local 
  authorities. Heavy rainfall could trigger flash flooding and 
  debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the burn scar, which may lead to flash flooding
    and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JMG
748 
WGUS66 KEKA 310831
FFAEKA

Flood Watch
National Weather Service Eureka CA
131 AM PDT Thu Aug 31 2023

CAZ107-312215-
/O.CON.KEKA.FF.A.0003.230901T1500Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-
131 AM PDT Thu Aug 31 2023

...FLASH FLOOD WATCH FOR THE RIVER COMPLEX BURN SCAR REMAINS IN 
EFFECT FROM FRIDAY MORNING THROUGH FRIDAY EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the River Complex burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Northern Trinity.

* WHEN...From Friday morning through Friday evening.

* IMPACTS...Heavy rainfall over the River Complex burn scar with 
  precipitation rates near an inch per hour will be possible during 
  the period of the watch. The threat for debris flows due to heavy 
  rainfall will be highest across the Coffee Creek drainage basin. 
  Be sure to stay up to date with information from local 
  authorities. Heavy rainfall could trigger flash flooding and 
  debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the River Complex burn scar, which may lead to
    flash flooding and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

SEC
129 
WGUS66 KEKA 312034
FFAEKA

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Eureka CA
134 PM PDT Thu Aug 31 2023

CAZ102-010445-
/O.EXB.KEKA.FF.A.0003.230901T1800Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Del Norte Interior-
134 PM PDT Thu Aug 31 2023

...FLASH FLOOD WATCH FOR THE SMITH RIVER AND SLATER BURN SCAR IN 
EFFECT FROM FRIDAY MORNING THROUGH FRIDAY EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall will be possible over the Smith River and Slater burn 
  scars.

* WHERE...A portion of northwest California, including the following 
  area, Del Norte Interior.

* WHEN...From Friday morning through Friday evening.

* IMPACTS...Heavy rainfall over the Smith River and Slater burn 
  scars with rainfal rates at or above a half inch per half hour 
  will be possible during the period of the watch. Residents near 
  the Smith River and Slater burn scar should prepare for potential 
  flooding impacts. Be sure to stay up to date with information from 
  local authorities. Heavy rainfall could trigger flash flooding and 
  debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the burn scar, which may lead to flash flooding
    and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ107-010445-
/O.CON.KEKA.FF.A.0003.230901T1500Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-
134 PM PDT Thu Aug 31 2023

...FLASH FLOOD WATCH FOR THE RIVER COMPLEX BURN SCAR REMAINS IN 
EFFECT FROM FRIDAY MORNING THROUGH FRIDAY EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the River Complex burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Northern Trinity.

* WHEN...From Friday morning through Friday evening.

* IMPACTS...Heavy rainfall over the River Complex burn scar with 
  rainfall rates near an inch per hour will be possible during the 
  period of the watch. The threat for debris flows due to heavy 
  rainfall will be highest across the Coffee Creek drainage basin. 
  Be sure to stay up to date with information from local 
  authorities. Heavy rainfall could trigger flash flooding and 
  debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the burn scar, which may lead to flash flooding
    and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JMG
163 
WGUS66 KEKA 312151
FFAEKA

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Eureka CA
251 PM PDT Thu Aug 31 2023

CAZ105-106-010600-
/O.EXA.KEKA.FF.A.0003.230901T1800Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Humboldt Interior-Southern Humboldt Interior-
251 PM PDT Thu Aug 31 2023

...FLASH FLOOD WATCH FOR THE PILOT AND 3-9 BURN SCAR IN EFFECT FROM 
FRIDAY MORNING THROUGH FRIDAY EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the Pilot and 3-9 burn scar.

* WHERE...A portion of northwest California, including the following 
  areas, Northern Humboldt Interior and Southern Humboldt Interior.

* WHEN...From Friday morning through Friday evening.

* IMPACTS...Heavy rainfall over the Pilot and 3-9 burn scar 
  thunderstorms with heavy rainfall in are expected up to and during 
  the period of the watch. Residents near the Pilot and 3-9 burn 
  scar should prepare for potential flooding impacts. Be sure to 
  stay up to date with information from local authorities. Heavy 
  rainfall could trigger flash flooding of low-lying areas, 
  urbanized street flooding, and debris flows in and near recent 
  wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the Pilot and 3-9 fire burn scars, which may
    lead to flash flooding and debris flows. Rain rates may
    exceed 0.5 inches in one hour.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ107-010600-
/O.CON.KEKA.FF.A.0003.230901T1500Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-
251 PM PDT Thu Aug 31 2023

...FLASH FLOOD WATCH FOR THE RIVER COMPLEX BURN SCAR REMAINS IN 
EFFECT FROM FRIDAY MORNING THROUGH FRIDAY EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the River Complex burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Northern Trinity.

* WHEN...From Friday morning through Friday evening.

* IMPACTS...Heavy rainfall over the River Complex burn scar with 
  rainfall rates near an inch per hour will be possible during the 
  period of the watch. The threat for debris flows due to heavy 
  rainfall will be highest across the Coffee Creek drainage basin. 
  Be sure to stay up to date with information from local 
  authorities. Heavy rainfall could trigger flash flooding and 
  debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the River Complex burn scar, which may lead to
    flash flooding and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ102-010600-
/O.CON.KEKA.FF.A.0003.230901T1800Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Del Norte Interior-
251 PM PDT Thu Aug 31 2023

...FLASH FLOOD WATCH FOR THE SMITH RIVER AND SLATER BURN SCAR 
REMAINS IN EFFECT FROM FRIDAY MORNING THROUGH FRIDAY EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall will be possible over the Smith River and Slater burn 
  scars.

* WHERE...A portion of northwest California, including the following 
  area, Del Norte Interior.

* WHEN...From Friday morning through Friday evening.

* IMPACTS...Heavy rainfall over the Smith River and Slater burn 
  scars with rainfall rates at or above a half inch per half hour 
  will be possible during the period of the watch. Residents near 
  the Smith River and Slater burn scar should prepare for potential 
  flooding impacts. Be sure to stay up to date with information from 
  local authorities. Heavy rainfall could trigger flash flooding and 
  debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the burn scar, which may lead to flash flooding
    and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JHW
712 
WGUS66 KEKA 010605
FFAEKA

Flood Watch
National Weather Service Eureka CA
1105 PM PDT Thu Aug 31 2023

CAZ107-011415-
/O.CON.KEKA.FF.A.0003.230901T1500Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-
1105 PM PDT Thu Aug 31 2023

...FLASH FLOOD WATCH FOR THE RIVER COMPLEX BURN SCAR REMAINS IN 
EFFECT FROM 8 AM PDT FRIDAY THROUGH FRIDAY EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the River Complex burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Northern Trinity.

* WHEN...From 8 AM PDT Friday through Friday evening.

* IMPACTS...Heavy rainfall over the River Complex burn scar heavy 
  rainfall near an inch per hour is possible up to and during the 
  period of the watch. The threat for debris flows due to heavy 
  rainfall will be highest across Coffee Creek. Be sure to stay up 
  to date with information from local authorities. Heavy rainfall 
  could trigger flash flooding of low-lying areas, urbanized street 
  flooding, and debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the burn scar, which may lead to flash flooding
    and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ102-011415-
/O.CON.KEKA.FF.A.0003.230901T1800Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Del Norte Interior-
1105 PM PDT Thu Aug 31 2023

...FLASH FLOOD WATCH FOR THE SMITH RIVER AND SLATER BURN SCAR 
REMAINS IN EFFECT FROM 11 AM PDT FRIDAY THROUGH FRIDAY EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the Smith River and Slater 
  burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Del Norte Interior.

* WHEN...From 11 AM PDT Friday through Friday evening.

* IMPACTS...Heavy rainfall over the Smith River and Slater burn scar 
  rainfall rates at or above a half inch per half hour will be 
  possible during the period of the watch. Residents near the Smith 
  River and Slater burn scar should prepare for potential flooding 
  impacts. Be sure to stay up to date with information from local 
  authorities. Heavy rainfall could trigger flash flooding of 
  low-lying areas, urbanized street flooding, and debris flows in 
  and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the burn scar, which may lead to flash flooding
    and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ105-106-011415-
/O.CON.KEKA.FF.A.0003.230901T1800Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Humboldt Interior-Southern Humboldt Interior-
1105 PM PDT Thu Aug 31 2023

...FLASH FLOOD WATCH FOR THE PILOT AND 3-9 BURN SCAR REMAINS IN 
EFFECT FROM 11 AM PDT FRIDAY THROUGH FRIDAY EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the Pilot and 3-9 burn scar.

* WHERE...A portion of northwest California, including the following 
  areas, Northern Humboldt Interior and Southern Humboldt Interior.

* WHEN...From 11 AM PDT Friday through Friday evening.

* IMPACTS...Heavy rainfall over the Pilot and 3-9 burn scar 
  thunderstorms with heavy rainfall in are expected up to and during 
  the period of the watch. Residents near the Pilot and 3-9 burn 
  scar should prepare for potential flooding impacts. Be sure to 
  stay up to date with information from local authorities. Heavy 
  rainfall could trigger flash flooding of low-lying areas, 
  urbanized street flooding, and debris flows in and near recent 
  wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the Pilot and 3-9 fire burn scars, which may
    lead to flash flooding and debris flows. Rain rates may
    exceed 0.5 inches in one hour.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

TDJ
573 
WGUS66 KEKA 011401
FFAEKA

Flood Watch
National Weather Service Eureka CA
701 AM PDT Fri Sep 1 2023

CAZ107-012215-
/O.CON.KEKA.FF.A.0003.230901T1500Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-
701 AM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE RIVER COMPLEX BURN SCAR REMAINS IN 
EFFECT THROUGH THIS EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the River Complex burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Northern Trinity.

* WHEN...Through this evening.

* IMPACTS...Heavy rainfall over the River Complex burn scar heavy 
  rainfall near an inch per hours is possible up to and during the 
  period of the watch. The threat for debris flows due to heavy 
  rainfall will be highest across Coffee Creek. should prepare for 
  potential flooding impacts. Be sure to stay up to date with 
  information from local authorities. Heavy rainfall could trigger 
  flash flooding of low-lying areas, urbanized street flooding, and 
  debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the River Complex burn scar, which may lead to
    flash flooding and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ102-012215-
/O.CON.KEKA.FF.A.0003.230901T1800Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Del Norte Interior-
701 AM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE SMITH RIVER AND SLATER BURN SCAR 
REMAINS IN EFFECT FROM 11 AM PDT THIS MORNING THROUGH THIS EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall will be possible over the Smith River and Slater burn 
  scars.

* WHERE...A portion of northwest California, including the following 
  area, Del Norte Interior.

* WHEN...From 11 AM PDT this morning through this evening.

* IMPACTS...Heavy rainfall over the Smith River and Slater burn 
  scars with rainfall rates at or above a half inch per half hour 
  will be possible during the period of the watch. Residents near 
  the Smith River and Slater burn scar should prepare for potential 
  flooding impacts. Be sure to stay up to date with information from 
  local authorities. Heavy rainfall could trigger flash flooding and 
  debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the burn scar, which may lead to flash flooding
    and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ105-106-012215-
/O.CON.KEKA.FF.A.0003.230901T1800Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Humboldt Interior-Southern Humboldt Interior-
701 AM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE PILOT AND 3-9 BURN SCAR REMAINS IN 
EFFECT FROM 11 AM PDT THIS MORNING THROUGH THIS EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the Pilot and 3-9 burn scar.

* WHERE...A portion of northwest California, including the following 
  areas, Northern Humboldt Interior and Southern Humboldt Interior.

* WHEN...From 11 AM PDT this morning through this evening.

* IMPACTS...Heavy rainfall over the Pilot and 3-9 burn scar 
  thunderstorms with heavy rainfall in are expected up to and during 
  the period of the watch. Residents near the Pilot and 3-9 burn 
  scar should prepare for potential flooding impacts. Be sure to 
  stay up to date with information from local authorities. Heavy 
  rainfall could trigger flash flooding of low-lying areas, 
  urbanized street flooding, and debris flows in and near recent 
  wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the Pilot and 3-9 fire burn scars, which may
    lead to flash flooding and debris flows. Rain rates may
    exceed 0.5 inches in one hour.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

SEC
214 
WGUS66 KEKA 011551
FFAEKA

Flood Watch
National Weather Service Eureka CA
851 AM PDT Fri Sep 1 2023

CAZ107-020000-
/O.CON.KEKA.FF.A.0003.000000T0000Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-
851 AM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE RIVER COMPLEX BURN SCAR REMAINS IN 
EFFECT THROUGH THIS EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the River Complex burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Northern Trinity.

* WHEN...Through this evening.

* IMPACTS...Heavy rainfall over the River Complex burn scar near an 
  inch per hour is possible during the period of the watch. The 
  threat for debris flows due to heavy rainfall will be highest 
  across the Coffee Creek drainage basine. Residents should prepare 
  for potential flooding impacts. Be sure to stay up to date with 
  information from local authorities. Heavy rainfall could trigger 
  flash flooding across wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the burn scar, which may lead to flash flooding
    and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ102-020000-
/O.CON.KEKA.FF.A.0003.230901T1800Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Del Norte Interior-
851 AM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE SMITH RIVER AND SLATER BURN SCAR 
REMAINS IN EFFECT THROUGH THIS EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the Smith River and Slater 
  burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Del Norte Interior.

* WHEN...Through this evening.

* IMPACTS...Heavy rainfall over the Smith River and Slater burn 
  scars at or above an inch per hour will be possible during the 
  period of the watch. Residents near the Smith River and Slater 
  burn scars should prepare for potential flooding impacts. Be sure 
  to stay up to date with information from local authorities. Heavy 
  rainfall could trigger flash flooding near recent wildfire burn 
  scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the burn scar, which may lead to flash flooding
    and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ105-106-020000-
/O.CON.KEKA.FF.A.0003.230901T1800Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Humboldt Interior-Southern Humboldt Interior-
851 AM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE PILOT AND 3-9 BURN SCAR REMAINS IN 
EFFECT THROUGH THIS EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the Pilot and 3-9 burn scar.

* WHERE...A portion of northwest California, including the following 
  areas, Northern Humboldt Interior and Southern Humboldt Interior.

* WHEN...Through this evening.

* IMPACTS...Heavy rainfall with rainfall rates near an inch per hour 
  over the Pilot and 3-9 burn scars will be possible with 
  thunderstorms. Residents near the Pilot and 3-9 burn scar should 
  prepare for potential flooding impacts. Be sure to stay up to date 
  with information from local authorities. Heavy rainfall could 
  trigger flash flooding near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the Pilot and 3-9 fire burn scars, which may
    lead to flash flooding and debris flows. Rain rates may
    exceed one inch per hour.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JMG
682 
WGUS66 KEKA 012130
FFAEKA

Flood Watch
National Weather Service Eureka CA
230 PM PDT Fri Sep 1 2023

CAZ107-020530-
/O.CON.KEKA.FF.A.0003.000000T0000Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-
230 PM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE RIVER COMPLEX BURN SCAR REMAINS IN 
EFFECT UNTIL 11 PM PDT THIS EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the River Complex burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Northern Trinity.

* WHEN...Until 11 PM PDT this evening.

* IMPACTS...Heavy rainfall over the River Complex burn scar heavy 
  rainfall near an inch per hour is possible during the period of 
  the watch. The threat for debris flows due to heavy rainfall will 
  be highest across Coffee Creek. Residents should prepare for 
  potential flooding impacts. Be sure to stay up to date with 
  information from local authorities. Heavy rainfall could trigger 
  flash flooding of low-lying areas, urbanized street flooding, and 
  debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the River Complex burn scar, which may lead to
    flash flooding and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ102-020530-
/O.CON.KEKA.FF.A.0003.000000T0000Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Del Norte Interior-
230 PM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE SMITH RIVER AND SLATER BURN SCAR 
REMAINS IN EFFECT UNTIL 11 PM PDT THIS EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall will be possible over the Smith River and Slater burn 
  scars.

* WHERE...A portion of northwest California, including the following 
  area, Del Norte Interior.

* WHEN...Until 11 PM PDT this evening.

* IMPACTS...Heavy rainfall over the Smith River and Slater burn 
  scars near an inch per hour will be possible during the period of 
  the watch. Residents near the Smith River and Slater burn scars 
  should prepare for potential flooding impacts. Be sure to stay up 
  to date with information from local authorities. Heavy rainfall 
  could trigger flash flooding near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the burn scar, which may lead to flash flooding
    and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ105-106-020530-
/O.CON.KEKA.FF.A.0003.000000T0000Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Humboldt Interior-Southern Humboldt Interior-
230 PM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE PILOT AND 3-9 BURN SCAR REMAINS IN 
EFFECT UNTIL 11 PM PDT THIS EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the Pilot and 3-9 burn scar.

* WHERE...A portion of northwest California, including the following 
  areas, Northern Humboldt Interior and Southern Humboldt Interior.

* WHEN...Until 11 PM PDT this evening.

* IMPACTS...Heavy rainfall with rainfall rates near an inch per hour 
  over the Pilot and 3-9 burn scars will be possible with 
  thunderstorms. Residents near the Pilot and 3-9 burn scar should 
  prepare for potential flooding impacts. Be sure to stay up to date 
  with information from local authorities. Heavy rainfall could 
  trigger flash flooding near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the Pilot and 3-9 fire burn scars, which may
    lead to flash flooding and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JMG
619 
WGUS66 KEKA 020030
FFAEKA

Flood Watch
National Weather Service Eureka CA
530 PM PDT Fri Sep 1 2023

CAZ102-020130-
/O.CAN.KEKA.FF.A.0003.000000T0000Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Del Norte Interior-
530 PM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE SMITH RIVER AND SLATER BURN SCAR HAS 
BEEN REPLACED WITH A FLASH FLOOD WARNING...

The Flash Flood Watch for the Smith River and Slater is replaced by 
a Flash Flood Warning for a portion of northwest California, 
including the following area, Del Norte Interior.

Please refer to that bulletin for more information.

$$

CAZ107-020600-
/O.CON.KEKA.FF.A.0003.000000T0000Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-
530 PM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE RIVER COMPLEX BURN SCAR REMAINS IN 
EFFECT UNTIL 11 PM PDT THIS EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the River Complex burn scar.

* WHERE...A portion of northwest California, including the following 
  area, Northern Trinity.

* WHEN...Until 11 PM PDT this evening.

* IMPACTS...Heavy rainfall over the River Complex burn scar heavy 
  rainfall near an inch per hours is possible up to and during the 
  period of the watch. The threat for debris flows due to heavy 
  rainfall will be highest across Coffee Creek. should prepare for 
  potential flooding impacts. Be sure to stay up to date with 
  information from local authorities. Heavy rainfall could trigger 
  flash flooding of low-lying areas, urbanized street flooding, and 
  debris flows in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the River Complex burn scar, which may lead to
    flash flooding and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

CAZ105-106-020600-
/O.CON.KEKA.FF.A.0003.000000T0000Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Humboldt Interior-Southern Humboldt Interior-
530 PM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE PILOT AND 3-9 BURN SCAR REMAINS IN 
EFFECT UNTIL 11 PM PDT THIS EVENING...

* WHAT...Flash flooding and debris flows caused by excessive 
  rainfall continue to be possible over the Pilot and 3-9 burn scar.

* WHERE...A portion of northwest California, including the following 
  areas, Northern Humboldt Interior and Southern Humboldt Interior.

* WHEN...Until 11 PM PDT this evening.

* IMPACTS...Heavy rainfall over the Pilot and 3-9 burn scar 
  thunderstorms with heavy rainfall in are expected up to and during 
  the period of the watch. Residents near the Pilot and 3-9 burn 
  scar should prepare for potential flooding impacts. Be sure to 
  stay up to date with information from local authorities. Heavy 
  rainfall could trigger flash flooding of low-lying areas, 
  urbanized street flooding, and debris flows in and near recent 
  wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the Pilot and 3-9 fire burn scars, which may
    lead to flash flooding and debris flows. Rain rates may
    exceed 0.5 inches in one hour.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

ZVS
878 
WGUS66 KEKA 020425
FFAEKA

Flood Watch
National Weather Service Eureka CA
925 PM PDT Fri Sep 1 2023

CAZ105>107-020530-
/O.CAN.KEKA.FF.A.0003.000000T0000Z-230902T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Humboldt Interior-Southern Humboldt Interior-Northern
Trinity-
925 PM PDT Fri Sep 1 2023

...FLASH FLOOD WATCH FOR THE PILOT AND 3-9 BURN SCAR AND RIVER 
COMPLEX BURN SCAR IS CANCELLED...

The Flash Flood Watch for the Pilot and 3-9 is cancelled for a 
portion of northwest California, including the following areas, 
Northern Humboldt Interior, Northern Trinity and Southern Humboldt 
Interior.

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

$$

ZVS

What forecasters said that day

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

NWS Eureka, CA wrote its last area forecast discussion before this flash flood watch went out at Aug 30, 4:55 AM PDT, 5 hours 56 minutes earlier.

Area forecast discussion, Aug 30, 4:55 AM PDT, 5 hours 56 minutes before
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
455 AM PDT Wed Aug 30 2023

.SYNOPSIS...Breezy north winds will continue through today. Dry
weather will transition to cooler and showery weather Friday
through Sunday.

&&

.DISCUSSION...Skies were mostly clear across much of the area
early this morning. However, low clouds and fog were noted along much
of the North Coast and the Eel River Valley as gusty coastal
northerly winds pooled low-level moisture against the coastal
terrain and up some of the adjacent river valleys. Visibilities were
being reduced to less than one mile in fog at times. Temperatures
mostly ranged from the mid 50s to mid 60s, with some 70+ readings
across parts of Lake County.

Aloft, flow is mostly zonal with a small upper low progressing E over
WA. An upper ridge currently stretches from the Pacific across S CA
and AZ. A rapidly amplifying upper trough is forecast to dig along
the Pacific Coast through Thursday. A deepening cut off low is
forecast to develop over W OR on Friday. This feature will move S
over N CA during the weekend before rapidly weakening and lifting
NE-E Sunday night and Monday. This feature will bring cooler and more
showery conditions to the area late in the week and into the weekend.
The highest rainfall amounts continue to be forecast for easternmost
areas- particularly Trinity County, where storm total rainfall may
approach one inch over the roughly 48-hour period from Thursday
evening through Saturday evening. Rainfall amounts closer to the
coast are expected to be closer to a tenth of an inch or less. The
ultimate position of the upper low will affect rainfall distribution
across the area. A path farther to the W would bring more rainfall to
coastal areas. Have introduced isolated thunderstorms to the
forecast, using NBM thunder probabilities of 15% or more to determine
locations of thunder. This may be a bit overdone, as increased cloud
cover will act to reduce instability. The best chance of thunder
looks to be Friday and Saturday afternoons. Storm motion is expected
to be quite slow for any Friday storms, which may lead to locally
heavy rainfall beneath these isolated storms. This is the time period
with the heaviest QPF amounts.

Dry weather is forecast to return late in the weekend into early next
week, with temperatures returning to near normal by Monday. /SEC

&&

.AVIATION...Low clouds and fog along the North Coast are bringing
conditions ranging from MVFR to LIFR at KCEC and KACV. Per ACV
profiler data, the marine layer appears to be around 2500 ft deep.
Conditions are expected to improve later this morning. Some haze will
linger during the morning, but most of this is expected to shift
farther inland later in the morning. Winds have decoupled very
effectively early this morning, but gusty NW winds are forecast to
return around midday. Have continued low-level wind shear at KACV
from mid-afternoon through early evening as winds are forecast to be
even high just above the surface during that time period. Low clouds
and fog are forecast to return early Thursday morning, but the extent
remains uncertain. At KUKI, VFR conditions are expected with
generally light winds. /SEC

&&

.MARINE...Stout northerlies continue in the southern waters where
gale conditions extend through Thursday morning before easing to
small craft conditions. An elongated troughing pattern will keep
northerlies at or near gale conditions for the northern outer waters
as well, building through the morning and peaking by the late
afternoon. The Gale Watch for the northern outer waters has been
upgraded to a Gale Warning starting this afternoon. Thursday evening
will see an overall diminishing in northerly winds with an exception
for the lee of Cape Mendocino, which will ease from localized gale
force gusts by Friday morning. Otherwise, a small mid-period NW
swell continues with a few long period NW and S swells are forecast
over the weekend. Winds will turn light and southerly through the
weekend. A slight sneaker wave threat may develop through Labor Day
weekend if the forecast trends higher in regards to the long period
NW swell. /EYS

&&

.FIRE WEATHER...N to NE winds are presently gusting over 30 mph
across E Lake County with relative humidity values around 30 percent.
So, the existing Red Flag Warning appears to be panning out. This
warning runs into this evening. Local gusts to 35 mph remain likely
for exposed ridges and upper slopes, with humidity values dropping
into the teens during the day. Elsewhere, cooler and more humid
conditions will mitigate the severity of fire weather conditions.

Later this week, cool showery weather will overspread the region
Friday through Sunday. Light beneficial rainfall will occur for
many locations, with up to an inch of accumulation forecast to occur
over portions of Trinity County. /SEC

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...Red Flag Warning until 8 PM this evening for CAZ264-277.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from noon today to 9 AM Thursday
      for PZZ450.
     Gale Warning until 9 AM Thursday for PZZ455-475.
     Small Craft Advisory until 2 PM this afternoon for PZZ470.
     Gale Warning from 2 PM this afternoon to midnight tonight
      for PZZ470.

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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png

Nearby

Flash Flood Watches in California, 2023Every flash flood watch in 2023

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.