Alert archive / California / Flood Watches in 2021

Flood Watch 3, NWS Eureka, CA

January 31, 20214 counties in California

NWS Eureka, CA issued this flood watch at Jan 31, 2021, 4:28 AM PST for 4 counties in California. It took effect at Jan 31, 2021, 10:00 AM PST. It was in force for 19 hr.

The area

The counties it named.

The facts

Issued
Jan 31, 2021, 4:28 AM PST (12:28 UTC)
In effect from
Jan 31, 2021, 10:00 AM PST
Expired
Feb 1, 2021, 5:16 AM PST
In force
19 hr
Issued by
NWS Eureka, CA
Flood severity
None

Counties Del Norte County, CA, Humboldt County, CA, Mendocino County, CA, Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 60 km from the middle of the area, began a volume at 12:27 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, 0.5 hours before the alert went out and 204 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 2021-01-31Temperature 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, Medford/Jackson, OR at 12:00Z on 2021-01-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 square meters per square second.1939Sfc1 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
1633 m above ground
0-6 km bulk shear
0 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
0 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

713 
WGUS66 KEKA 311228
FFAEKA

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Eureka CA
428 AM PST Sun Jan 31 2021



.An atmospheric river will focus near the northwest California
coast much of Sunday and Monday, before shifting eastward across
our area with a cold front late Monday or Monday night. Periods of
moderate to heavy rainfall will result, on top of areas where
soils have been saturated from recent rains, and heavy snowpack is
present. The focus of the heavier rain has shifted a bit farther
north and west though, lowering the threat for much of Mendocino
County.

CAZ101>106-108>111-312030-
/O.CAN.KEKA.FA.A.0002.000000T0000Z-210202T1200Z/
/O.NEW.KEKA.FA.A.0003.210131T1800Z-210202T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal Del Norte-Del Norte Interior-Northern Humboldt Coast-
Southwestern Humboldt-Northern Humboldt Interior-
Southern Humboldt Interior-Southern Trinity-Mendocino Coast-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
428 AM PST Sun Jan 31 2021

...FLOOD WATCH IN EFFECT FROM 10 AM PST THIS MORNING THROUGH LATE
MONDAY NIGHT...

The National Weather Service in Eureka has issued a

* Flood Watch for a portion of northwest California, including 
  the following areas, Coastal Del Norte, Del Norte Interior, 
  Mendocino Coast, Northeastern Mendocino Interior, Northern 
  Humboldt Coast, Northern Humboldt Interior, Northwestern 
  Mendocino Interior, Southern Humboldt Interior, Southern 
  Trinity, and Southwestern Humboldt. 

* From 10 AM PST this morning through late Monday night

*  2 to 4 inches of rain is expected from today through Monday 
   night across coastal and valley locations. 5 to 7 inches 
   expected across southwest facing mountains and ridges. Heavy 
   rain combined with saturated soil and melting snow across the 
   mountains will contribute toward possible flooding. 


* Low lying areas, creeks, streams, culverts, and portions of
  urban areas may experience flooding due to heavy rainfall.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flood Watch means there is a potential for flooding based on
current forecasts. You should monitor later forecasts and be
alert for possible flood warnings. Those living in areas prone to
flooding should be prepared to take action should flooding
develop.

&&
 


$$
JJW
3 follow-up statements
040 
WGUS66 KEKA 311753
FFAEKA

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Eureka CA
953 AM PST Sun Jan 31 2021

.An atmospheric river will focus near the northwest California
coast today, the bulk of heavier rains today and tonight will be
limited to southwest Humboldt and Del Norte County, before 
shifting eastward across the rest of our area with a cold front 
on Monday. Periods of moderate to heavy rainfall are still
expected through tonight in southwest Humboldt and Del Norte, with
more widespread moderate to occasionally heavy rain on Monday. Soils
have been saturated from recent rains, and heavy snowpack is 
present across much of the mountainous terrain, enhancing the risk
of flooding in the flood watch area. The duration and amounts of
any heavier rain is now less than earlier expected for the
northern Humboldt coast and Mendocino County. 


CAZ103-109>111-311900-
/O.CAN.KEKA.FA.A.0003.210131T1800Z-210202T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Humboldt Coast-Mendocino Coast-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
953 AM PST Sun Jan 31 2021

...FLOOD WATCH IS CANCELLED...

The Flood Watch for a portion of northwest California has been
cancelled. The main area of moderate to heavier rain is
shifting just offshore today, and the bulk of the latest forecast
guidance keeps heavier rain just offshore until Monday morning 
(with the exception of southwest Humboldt and Del Norte County).
Total rainfall through Monday night of 1 to 2 inches, with locally
over 3 inches in the mountains of northern Humboldt and northwest
Mendocino, is still forecast, but the risk of flooding has
diminished. 

$$

CAZ105-106-108-010200-
/O.EXT.KEKA.FA.A.0003.210201T1400Z-210202T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Humboldt Interior-Southern Humboldt Interior-
Southern Trinity-
953 AM PST Sun Jan 31 2021

...FLOOD WATCH NOW IN EFFECT FROM MONDAY MORNING THROUGH LATE
MONDAY NIGHT...

The Flood Watch is now in effect for

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

* From Monday morning through late Monday night

* An additional 1 to 3 inches of rain is expected through Monday
  night across coastal and valley locations. 3 to 5 inches
  expected across southwest facing mountains and ridges, much of
  which will fall on Monday. Heavy rain combined with saturated 
  soil and melting snow across the mountains will contribute 
  toward possible flooding. 

* Low lying areas, creeks, streams, culverts, and portions of 
  urban areas may experience flooding due to heavy rainfall. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flood Watch means there is a potential for flooding based on
current forecasts. You should monitor later forecasts and be
alert for possible flood warnings. Those living in areas prone to
flooding should be prepared to take action should flooding
develop.

&&

$$

CAZ101-102-104-010200-
/O.CON.KEKA.FA.A.0003.210131T1800Z-210202T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal Del Norte-Del Norte Interior-Southwestern Humboldt-
953 AM PST Sun Jan 31 2021

...FLOOD WATCH REMAINS IN EFFECT THROUGH LATE MONDAY NIGHT...

The Flood Watch continues for

* A portion of northwest California, including the following 
  areas, Coastal Del Norte, Del Norte Interior, and Southwestern 
  Humboldt. 

* Through late Monday night

* 3 to 4 inches of rain is expected through Monday night across 
  coastal and valley locations. 5 to 7 inches expected across 
  southwest facing mountains and ridges. Heavy rain combined with 
  saturated soil (and melting snow across the mountains) will 
  contribute toward possible flooding. 

* Low lying areas, creeks, streams, culverts, and portions of 
  urban areas may experience flooding due to heavy rainfall. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flood Watch means there is a potential for flooding based on
current forecasts. You should monitor later forecasts and be
alert for possible flood warnings. Those living in areas prone to
flooding should be prepared to take action should flooding
develop.

&&

$$
224 
WGUS66 KEKA 010210
FFAEKA

Flood Watch
National Weather Service Eureka CA
610 PM PST Sun Jan 31 2021

CAZ101-102-104>106-108-011415-
/O.CON.KEKA.FA.A.0003.000000T0000Z-210202T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal Del Norte-Del Norte Interior-Southwestern Humboldt-Northern
Humboldt Interior-Southern Humboldt Interior-Southern Trinity-
610 PM PST Sun Jan 31 2021

...FLOOD WATCH REMAINS IN EFFECT THROUGH LATE MONDAY NIGHT...

The Flood Watch continues for

* A portion of northwest California, including the following areas, 
  Coastal Del Norte, Del Norte Interior, Northern Humboldt Interior, 
  Southern Humboldt Interior, Southern Trinity and Southwestern 
  Humboldt.

* Through late Monday night

* A total of 2 to 4 inches of rain is expected through Monday night 
  across coastal locations. Total of 4 to 6 inches expected across
  southwest facing mountains and ridges. Heavy rain combined with 
  saturated soil (and melting snow across the mountains) will 
  contribute toward possible flooding.

* Low lying areas, creeks, streams, culverts, and portions of 
  urban areas may experience flooding due to heavy rainfall. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flood Watch means there is a potential for flooding based on
current forecasts. You should monitor later forecasts and be
alert for possible flood warnings. Those living in areas prone to
flooding should be prepared to take action should flooding
develop.

&&

$$

CB
328 
WGUS66 KEKA 011316
FFAEKA

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Eureka CA
516 AM PST Mon Feb 1 2021


CAZ101-102-104>106-108-012130-
/O.CAN.KEKA.FA.A.0003.000000T0000Z-210202T1200Z/
/O.NEW.KEKA.FA.A.0004.210201T1800Z-210202T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal Del Norte-Del Norte Interior-Southwestern Humboldt-
Northern Humboldt Interior-Southern Humboldt Interior-
Southern Trinity-
516 AM PST Mon Feb 1 2021

...FLOOD WATCH IN EFFECT FROM 10 AM PST THIS MORNING THROUGH LATE
TONIGHT...

The National Weather Service in Eureka has issued a

* Flood Watch for a portion of northwest California, including 
  the following areas, Coastal Del Norte, Del Norte Interior, 
  Northern Humboldt Interior, Southern Humboldt Interior, 
  Southern Trinity, and Southwestern Humboldt. 

* From 10 AM PST this morning through late tonight

* A total of 2 to 4 inches of additional rain is expected through
  Monday night across the area. Heavy rain combined with 
  saturated soil (and melting snow across the mountains) will 
  contribute toward possible flooding. 

* Low lying areas, creeks, streams, culverts, and portions of
  urban areas may experience flooding due to heavy rainfall. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flood Watch means there is a potential for flooding based on
current forecasts. You should monitor later forecasts and be
alert for possible flood warnings. Those living in areas prone to
flooding should be prepared to take action should flooding
develop.

&&


$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 31, 8:43 AM PSTSmall Craft AdvisoryEKA52 hr

Nearby

Flood Watches in California, 2021Every flood watch 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.