Alert archive / California / Flash Flood Watches in 2018

Flash Flood Watch 3, NWS Eureka, CA

November 27, 2018Mendocino County, California

NWS Eureka, CA issued this flash flood watch at Nov 27, 2018, 2:04 PM PST for Mendocino County, California. It took effect at Nov 28, 2018, 10:00 PM PST. It was in force for 18 hr.

The area

The counties it named.

The facts

Issued
Nov 27, 2018, 2:04 PM PST (22:04 UTC)
In effect from
Nov 28, 2018, 10:00 PM PST
Expired
Nov 29, 2018, 4:00 PM PST
In force
18 hr
Issued by
NWS Eureka, CA
Flood severity
None

County Mendocino County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 139 km from the middle of the area, began a volume at 22:07 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, 10.1 hours before the alert went out and 218 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 2018-11-27Temperature 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 2018-11-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.19395878Sfc1 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
916 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
144 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

370 
WGUS66 KEKA 272204
FFAEKA

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Eureka CA
204 PM PST Tue Nov 27 2018


CAZ107-110-113-280615-
/O.NEW.KEKA.FF.A.0003.181129T0600Z-181129T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-Northwestern Mendocino Interior-
Southeastern Mendocino Interior-
204 PM PST Tue Nov 27 2018

...FLASH FLOOD WATCH IN EFFECT FROM WEDNESDAY EVENING THROUGH
THURSDAY MORNING FOR THE CARR, DELTA, AND MENDOCINO COMPLEX
WILDFIRE BURN AREAS...

The National Weather Service in Eureka has issued a

* Flash Flood Watch for a portion of northwest California,
  including the Carr and Delta burn areas in Northern Trinity
  County, and the Mendocino Complex burn area in Northwestern
  Mendocino Interior and Southeastern Mendocino Interior. 

* From Wednesday evening through Thursday morning.

* Flash floods and debris flows will be a particular threat in the
  wildfire burn areas mentioned above. Heavy rainfall at times is
  possible over the burn areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

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

&&

$$
7 follow-up statements
377 
WGUS66 KEKA 280613
FFAEKA

Flood Watch
National Weather Service Eureka CA
1013 PM PST Tue Nov 27 2018


CAZ107-110-113-281415-
/O.CON.KEKA.FF.A.0003.181129T0600Z-181129T1800Z/
/00000.0.OT.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-Northwestern Mendocino Interior-
Southeastern Mendocino Interior-
1013 PM PST Tue Nov 27 2018

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM WEDNESDAY EVENING
THROUGH THURSDAY MORNING FOR THE CARR, DELTA, AND MENDOCINO 
COMPLEX WILDFIRE BURN AREAS...

The Flash Flood Watch continues for

* Flash Flood Watch for a portion of northwest California,
  including the Carr and Delta burn areas in Northern Trinity
  County, and the Mendocino Complex burn area in Northwestern
  Mendocino Interior and Southeastern Mendocino Interior. 

* From Wednesday evening through Thursday morning

* Flash floods and debris flows will be a particular threat in the
  wildfire burn areas mentioned above. Heavy rainfall at times is
  possible over the burn areas. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

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

&&

$$
827 
WGUS66 KEKA 281139
FFAEKA

Flood Watch
National Weather Service Eureka CA
339 AM PST Wed Nov 28 2018

CAZ107-110-113-282315-
/O.CON.KEKA.FF.A.0003.181129T0600Z-181129T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-Northwestern Mendocino Interior-
Southeastern Mendocino Interior-
339 AM PST Wed Nov 28 2018
 
...FLASH FLOOD WATCH REMAINS IN EFFECT FROM THIS EVENING THROUGH 
THURSDAY MORNING FOR THE CARR, DELTA, AND MENDOCINO COMPLEX 
WILDFIRE BURN AREAS...

The Flash Flood Watch continues for

* Flash Flood Watch for a portion of northwest California,
  including the Carr and Delta burn areas in Northern Trinity
  County, and the Mendocino Complex burn area in Northwestern
  Mendocino Interior and Southeastern Mendocino Interior. 

* From this evening through Thursday morning

* Flash floods and debris flows will be a particular threat in the
  wildfire burn areas mentioned above. Heavy rainfall at times is
  possible over the burn areas. 


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

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

&&

$$
795 
WGUS66 KEKA 282224
FFAEKA

Flood Watch
National Weather Service Eureka CA
224 PM PST Wed Nov 28 2018


CAZ107-110-113-290630-
/O.CON.KEKA.FF.A.0003.181129T0600Z-181129T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-Northwestern Mendocino Interior-
Southeastern Mendocino Interior-
224 PM PST Wed Nov 28 2018

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM THIS EVENING THROUGH 
THURSDAY MORNING FOR THE CARR, DELTA, AND MENDOCINO COMPLEX 
WILDFIRE BURN AREAS...

The Flash Flood Watch continues for

* Flash Flood Watch for a portion of northwest California,
  including the Carr and Delta burn areas in Northern Trinity
  County, and the Mendocino Complex burn area in Northwestern
  Mendocino Interior and Southeastern Mendocino Interior. 

* From this evening through Thursday morning

* Flash floods and debris flows will be a particular threat in the
  wildfire burn areas mentioned above. Heavy rainfall at times is
  possible over the burn areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

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

&&

$$
752 
WGUS66 KEKA 290648
FFAEKA

Flood Watch
National Weather Service Eureka CA
1048 PM PST Wed Nov 28 2018

CAZ107-110-113-291500-
/O.CON.KEKA.FF.A.0003.000000T0000Z-181129T1800Z/
/00000.0.OT.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-Northwestern Mendocino Interior-
Southeastern Mendocino Interior-
1048 PM PST Wed Nov 28 2018

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 10 AM PST THURSDAY
FOR THE CARR, DELTA, AND MENDOCINO COMPLEX WILDFIRE BURN AREAS...

The Flash Flood Watch continues for

* Flash Flood Watch for a portion of northwest California,
  including the Carr and Delta burn areas in Northern Trinity
  County, and the Mendocino Complex burn area in Northwestern
  Mendocino Interior and Southeastern Mendocino Interior. 

* Until 10 AM PST Thursday

* Flash floods and debris flows will be a particular threat in the
  wildfire burn areas mentioned above. Heavy rainfall at times is
  possible over the burn areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

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

&&

$$
570 
WGUS66 KEKA 291118
FFAEKA

Flood Watch
National Weather Service Eureka CA
318 AM PST Thu Nov 29 2018

CAZ107-110-113-291800-
/O.CON.KEKA.FF.A.0003.000000T0000Z-181129T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-Northwestern Mendocino Interior-
Southeastern Mendocino Interior-
318 AM PST Thu Nov 29 2018

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 10 AM PST THIS MORNING
FOR THE CARR, DELTA, AND MENDOCINO COMPLEX WILDFIRE BURN AREAS...

The Flash Flood Watch continues for

* Flash Flood Watch for a portion of northwest California,
  including the Carr and Delta burn areas in Northern Trinity
  County, and the Mendocino Complex burn area in Northwestern
  Mendocino Interior and Southeastern Mendocino Interior. 

* Until 10 AM PST Thursday

* Flash floods and debris flows will be a particular threat in the
  wildfire burn areas mentioned above. Heavy rainfall at times is
  possible over the burn areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

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

&&

$$
668 
WGUS66 KEKA 291611
FFAEKA

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Eureka CA
811 AM PST Thu Nov 29 2018

CAZ107-110-113-300000-
/O.EXT.KEKA.FF.A.0003.000000T0000Z-181130T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-Northwestern Mendocino Interior-
Southeastern Mendocino Interior-
811 AM PST Thu Nov 29 2018

...FLASH FLOOD WATCH NOW IN EFFECT UNTIL 4 PM PST THIS
AFTERNOON FOR THE CARR, DELTA, AND MENDOCINO COMPLEX WILDFIRE BURN
AREAS...

The Flash Flood Watch is now in effect for

* Flash Flood Watch for a portion of northwest California,
  including the Carr and Delta burn areas in Northern Trinity
  County, and the Mendocino Complex burn area in Northwestern
  Mendocino Interior and Southeastern Mendocino Interior. 

* Until 4 PM PST this afternoon

* Flash floods and debris flows due to heavy rain will be a
  particular threat in the wildfire burn areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

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

&&

$$
687 
WGUS66 KEKA 300004
FFAEKA

Flood Watch
National Weather Service Eureka CA
404 PM PST Thu Nov 29 2018

CAZ107-110-113-300115-
/O.EXP.KEKA.FF.A.0003.000000T0000Z-181130T0000Z/
/00000.0.OT.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Trinity-Northwestern Mendocino Interior-
Southeastern Mendocino Interior-
404 PM PST Thu Nov 29 2018

...FLASH FLOOD WATCH HAS EXPIRED...

The Flash Flood Watch for a portion of northwest California including
the Carr and Delta burn areas in Northern Trinity County, and the
Mendocino Complex burn area in Northwestern Mendocino Interior 
and Southeastern Mendocino Interior has expired. Light rain
showers will remain possible over these areas through this
evening.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 26, 9:00 PM PSTHigh Surf AdvisoryEKADel Norte, Humboldt, Mendocino38 hr
Nov 27, 10:10 AM PSTGale WatchEKA17 hr
Nov 27, 2:10 PM PSTWind AdvisoryEKAMendocino56 hr

Nearby

Flash Flood Watches in California, 2018Every flash flood watch in 2018

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.