Alert archive / California / Flash Flood Warnings in 2021

Flash Flood Warning 2, NWS Eureka, CA

August 1, 2021Del Norte County, California

NWS Eureka, CA issued this flash flood warning at Aug 1, 2021, 4:02 PM PDT for Del Norte County, California. It was in force for 58 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 1, 2021, 4:02 PM PDT (23:02 UTC)
Expired
Aug 1, 2021, 5:00 PM PDT
In force
58 min
Issued by
NWS Eureka, CA
Area
Storm-based polygon
Flood severity
None

County Del Norte County, CA

The radar

The Medford radar (KMAX), 80 km from the middle of the area, began a volume at 23:01 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, 11.0 hours before the alert went out and 85 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 2021-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 46 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
46 J/kg
Mixed-layer CIN
-456 J/kg
Mixed-layer LCL
1945 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
-10 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

413 
WGUS56 KEKA 012302
FFWEKA
CAC015-020000-
/O.NEW.KEKA.FF.W.0002.210801T2302Z-210802T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Eureka CA
402 PM PDT Sun Aug 1 2021

The National Weather Service in Eureka has issued a

* Flash Flood Warning for...
  The Slater burn scar in...
  Northeastern Del Norte County in northwestern California...

* Until 500 PM PDT.

* At 402 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain over the Slater Burn Scar. Between 0.5 and 1.0 inches 
  of rain have fallen. The expected rainfall rate is 0.75 to 1.5 
  inches in 1 hour. Flash flooding is ongoing or expected to begin 
  shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the Eastern Side of Slater Burn Scar. The debris flow 
can consist of rock, mud, vegetation and other loose materials.

  HAZARD...Flash flooding caused by thunderstorms in and around
           the Slater Burn Scar.

  SOURCE...Radar.

  IMPACT...Flooding of areas in and around the Eastern Half of
           the Slater Burn Scar.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life threatening situation. Heavy rainfall will cause 
extensive and severe flash flooding of creeks...streams...and 
ditches in the Slater Burn Scar. Severe debris flows can also be 
anticipated across roads. Roads and driveways may be washed away in 
places. If you encounter flood waters...climb to safety.

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Move to higher ground now. Act quickly to protect your life.

&&

LAT...LON 4197 12377 4197 12374 4199 12377 4200 12376
      4200 12352 4199 12354 4195 12354 4195 12357
      4192 12356 4190 12360 4191 12364 4196 12363
      4192 12376 4194 12375 4195 12378

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...0.75-1.5 INCHES IN 1 HOUR

$$

JAW
1 follow-up statement
119 
WGUS76 KEKA 012359
FFSEKA

Flash Flood Statement
National Weather Service Eureka CA
459 PM PDT Sun Aug 1 2021

CAC015-020009-
/O.EXP.KEKA.FF.W.0002.000000T0000Z-210802T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Del Norte CA-
459 PM PDT Sun Aug 1 2021

...FLASH FLOOD WARNING FOR THE SLATER BURN SCAR WILL EXPIRE AT 5 PM 
PDT THIS AFTERNOON FOR NORTHEASTERN DEL NORTE COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 4197 12377 4197 12374 4199 12377 4200 12376
      4200 12352 4199 12354 4195 12354 4195 12357
      4192 12356 4190 12360 4191 12364 4196 12363
      4192 12376 4194 12375 4195 12378

$$

JAW

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 6:34 PM PDTAreal Flood AdvisoryEKATrinity79 min

Nearby

Flash Flood Warnings in California, 2021Every flash flood 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.