Alert archive / California / Flash Flood Warnings in 2021

Flash Flood Warning 10, NWS Reno, NV

August 13, 2021Lassen County, Plumas County, California

NWS Reno, NV issued this flash flood warning at Aug 13, 2021, 5:19 PM PDT for Lassen County, Plumas County, California. It was in force for 116 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 13, 2021, 5:19 PM PDT (00:19 UTC)
Expired
Aug 13, 2021, 7:15 PM PDT
In force
116 min
Issued by
NWS Reno, NV
Area
Storm-based polygon
Flood severity
None

Counties Lassen County, CA, Plumas County, CA

The radar

The Beale AFB radar (KBBX), 115 km from the middle of the area, began a volume at 00:20 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

Reno, NV (KREV), launched 00:00Z, 0.3 hours before the alert went out and 231 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, Reno, NV at 00:00Z on 2021-08-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 54 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, Reno, NV at 00:00Z on 2021-08-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 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
54 J/kg
Mixed-layer CIN
-217 J/kg
Mixed-layer LCL
2997 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
243 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

155 
WGUS55 KREV 140019
FFWREV
CAC035-063-140215-
/O.NEW.KREV.FF.W.0010.210814T0019Z-210814T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Reno NV
519 PM PDT Fri Aug 13 2021

The National Weather Service in Reno has issued a

* Flash Flood Warning for...
  The Sheep Fire burn scar in...
  Southwestern Lassen County in northern California...
  Plumas County in northern California...

* Until 715 PM PDT.

* At 519 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain over the Sheep Fire Burn Scar. Flash flooding is 
  ongoing or expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the Light's Creek Drainage. The debris flow can 
consist of rock, mud, vegetation and other loose materials.

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

  SOURCE...Radar.

  IMPACT...Flooding of areas in and around the Sheep Fire Burn
           Scar.

* Some locations that will experience flash flooding include...
  mainly rural areas of Southwestern Lassen and Plumas Counties

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 Sheep Fire 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.

The drainage leads into the ongoing Dixie Wildfire.

&&

LAT...LON 4030 12078 4032 12075 4032 12073 4030 12071
      4029 12070 4027 12071 4021 12076 4018 12085

FLASH FLOOD...RADAR INDICATED

$$

DJ
1 follow-up statement
950 
WGUS75 KREV 140213
FFSREV

Flash Flood Statement
National Weather Service Reno NV
713 PM PDT Fri Aug 13 2021

CAC035-063-140223-
/O.EXP.KREV.FF.W.0010.000000T0000Z-210814T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lassen CA-Plumas CA-
713 PM PDT Fri Aug 13 2021

...FLASH FLOOD WARNING FOR THE SHEEP FIRE BURN SCAR WILL EXPIRE AT 
715 PM PDT THIS EVENING FOR SOUTHWESTERN LASSEN AND PLUMAS 
COUNTIES...

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

LAT...LON 4030 12078 4032 12075 4032 12073 4030 12071
      4029 12070 4027 12071 4021 12076 4018 12085

$$

TF

The office that day

Everything else NWS Reno, NV issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 14, 1:46 AM PDTHeat AdvisoryREVModoc69 hr

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.