Alert archive / California / Flash Flood Warnings in 2021

Flash Flood Warning 15, NWS Hanford, CA

August 14, 2021Tulare County, California

NWS Hanford, CA issued this flash flood warning at Aug 14, 2021, 4:57 PM PDT for Tulare County, California. It was in force for 82 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 14, 2021, 4:57 PM PDT (23:57 UTC)
Expired
Aug 14, 2021, 6:19 PM PDT
In force
82 min
Issued by
NWS Hanford, CA
Area
Storm-based polygon
Flood severity
None

County Tulare County, CA

The radar

The San Joaquin Valley radar (KHNX), 105 km from the middle of the area, began a volume at 23:58 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

Vandenberg AFB, CA (KVBG), launched 12:00Z, 12.0 hours before the alert went out and 250 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, Vandenberg AFB, CA at 12:00Z on 2021-08-14Temperature 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, Vandenberg AFB, CA at 12:00Z on 2021-08-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 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
1425 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

465 
WGUS56 KHNX 142357
FFWHNX
CAC107-150130-
/O.NEW.KHNX.FF.W.0015.210814T2357Z-210815T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Joaquin Valley CA
457 PM PDT Sat Aug 14 2021

The National Weather Service in Hanford CA has issued a

* Flash Flood Warning for...
  East central Tulare County in central California...

* Until 630 PM PDT.

* At 454 PM PDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area.  Flash flooding is ongoing or
  expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms in and around the 
           SQF COMPLEX BURN AREA.

  SOURCE...Radar indicated.

  IMPACT...Flooding of areas in and around the SQF COMPLEX BURN 
           AREA.

  The debris flow can consist of rock, mud, vegetation and other 
  loose materials.

* Some locations that will experience flooding include...
  Kern Canyon Ranger Station.

  ESPECIALLY VULNERABLE LOCATIONS INCLUDE: Severely burned areas in 
  steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Heavy rainfall can cause extensive and severe flash flooding of 
creeks and streams. Debris flows may also be anticipated across 
roads. Roadways and bridges may be washed away in places. Stay off 
the roads in the warned area. If you encounter flood waters...climb 
to safety.

Move away from recently burned areas. Life-threatening flooding of
creeks, roads and normally dry arroyos is likely. The heavy rains
will likely trigger rockslides, mudslides and debris flows in steep
terrain, especially in and around these areas.

&&

LAT...LON 3626 11862 3625 11848 3651 11841 3628 11838
      3628 11831 3611 11832 3610 11840 3622 11862

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

KM
2 follow-up statements
936 
WGUS76 KHNX 150008
FFSHNX

Flash Flood Statement
National Weather Service San Joaquin Valley CA
508 PM PDT Sat Aug 14 2021

CAC107-150130-
/O.CON.KHNX.FF.W.0015.000000T0000Z-210815T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Tulare CA-
508 PM PDT Sat Aug 14 2021

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM PDT FOR
EAST CENTRAL TULARE COUNTY...

At 503 PM PDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area.  Flash flooding is ongoing or expected
to begin shortly.

HAZARD...Flash flooding caused by thunderstorms moving west at 5 mph
         in and around the SQF COMPLEX BURNED AREA.

SOURCE...Radar indicated.

IMPACT...Flooding of areas in and around the SQF COMPLEX BURN AREA.

The debris flow can consist of rock, mud, vegetation and other loose 
materials.

Some locations that will experience flooding include...
Kern Canyon Ranger Station.

ESPECIALLY VULNERABLE LOCATIONS INCLUDE: Severely burned areas in 
steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move away from recently burned areas. The heavy rains may trigger 
rockslides, mudslides and debris flows in steep terrain, especially 
in and around these areas.

Remain alert for flooding even in locations not receiving rain.
Arroyos, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3626 11862 3625 11848 3651 11841 3628 11838
      3628 11831 3611 11832 3610 11840 3622 11862

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

KM
461 
WGUS76 KHNX 150119
FFSHNX

Flash Flood Statement
National Weather Service San Joaquin Valley CA
619 PM PDT Sat Aug 14 2021

CAC107-150127-
/O.CAN.KHNX.FF.W.0015.000000T0000Z-210815T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Tulare CA-
619 PM PDT Sat Aug 14 2021

...THE FLASH FLOOD WARNING FOR EAST CENTRAL TULARE COUNTY IS
CANCELLED...

The thunderstorms have ended, although be aware that there may be 
some standing water in the area. 

LAT...LON 3626 11862 3625 11848 3651 11841 3628 11838
      3628 11831 3611 11832 3610 11840 3622 11862

$$

KM

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.