Alert archive / California / Flash Flood Warnings in 2021

Flash Flood Warning 16, NWS San Francisco Bay Area, CA

December 13, 2021Monterey County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Dec 13, 2021, 1:45 PM PST for Monterey County, California. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Dec 13, 2021, 1:45 PM PST (21:45 UTC)
Expired: Dec 13, 2021, 8:00 PM PST
In force: 6 hr
Issued by: NWS San Francisco Bay Area, CA
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Monterey County, CA

The radar

The San Francisco radar (KMUX), 101 km from the middle of the area, began a volume at 21:49 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, 9.8 hours before the alert went out and 170 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 449 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 299 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

104 
WGUS56 KMTR 132145
FFWMTR
CAC053-140400-
/O.NEW.KMTR.FF.W.0016.211213T2145Z-211214T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
145 PM PST Mon Dec 13 2021

The National Weather Service in San Francisco has issued a

* Flash Flood Warning for...
  The Dolan, Carmel, River, Willow burn area in...
  Southwestern Monterey County in central California...

* Until 800 PM PST Monday.

* At 145 PM PST, Doppler radar and automated rain gauges indicated 
  heavy rain falling over the Dolan, Carmel, River, and Willow Burn 
  Areas. Between 2 and 3 inches of rain have fallen. Additional 
  rainfall amounts of 2 to 3 inches are possible in the warned area. 
  Flash flooding is ongoing or expected to begin shortly.

Excessive rainfall over the burn areas will result in debris flow 
moving through the Dolan, Carmel, River, and Willow Fire burn areas. 
The debris flow can consist of rock, mud, vegetation and other loose 
materials.

  HAZARD...Life threatening flash flooding. Heavy rain producing
           flash flooding in and around the Dolan, Carmel, River,
           and Willow Burn Areas.

  SOURCE...Radar and automated gauges.

  IMPACT...Life threatening flash flooding of areas in and around
           the Dolan, Carmel, River, and Willow Burn Areas.

* Some locations that will experience flash flooding include...
  Tassajara Hot Springs, Lucia, Carmel Valley, Esalen Institute and 
  Julia Pfeiffer Burns State Park.

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 Dolan, Carmel, River, and Willow Burn Areas. 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.

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.

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

&&

LAT...LON 3645 12173 3643 12161 3649 12164 3652 12161
      3660 12170 3655 12155 3640 12143 3639 12151
      3615 12148 3613 12138 3597 12126 3594 12147
      3615 12167 3618 12167 3613 12157 3621 12149
      3620 12151 3620 12154 3620 12157 3636 12151

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

MTR

2 follow-up statements

415 
WGUS76 KMTR 140123
FFSMTR

Flash Flood Statement
National Weather Service San Francisco CA
523 PM PST Mon Dec 13 2021

CAC053-140400-
/O.CON.KMTR.FF.W.0016.000000T0000Z-211214T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monterey CA-
523 PM PST Mon Dec 13 2021

...FLASH FLOOD WARNING FOR THE DOLAN, CARMEL, RIVER, WILLOW BURN 
AREA REMAINS IN EFFECT UNTIL 8 PM PST THIS EVENING FOR SOUTHWESTERN 
MONTEREY COUNTY...

At 523 PM PST, Doppler radar and automated rain gauges indicated 
heavy rain falling over the Dolan, Carmel, River, and Willow Burn 
Areas. Between 2 and 3 inches of rain have fallen. Additional 
rainfall amounts of 2 to 3 inches are possible in the warned area. 
Flash flooding is ongoing or expected to begin shortly.

Excessive rainfall over the burn areas will result in debris flow 
moving through the Dolan, Carmel, River, and Willow Fire burn areas. 
The debris flow can consist of rock, mud, vegetation and other loose 
materials.

HAZARD...Life threatening flash flooding. Heavy rain producing
         flash flooding in and around the Dolan, Carmel, River,
         and Willow Burn Areas.

SOURCE...Radar and automated gauges.

IMPACT...Life threatening flash flooding of areas in and around
         the Dolan, Carmel, River, and Willow Burn Areas.

Some locations that will experience flash flooding include...
  Tassajara Hot Springs, Lucia, Carmel Valley, Esalen Institute and 
  Julia Pfeiffer Burns State Park.

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 Dolan, Carmel, River, and Willow Burn Areas. 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.

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.

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

&&

LAT...LON 3645 12173 3643 12161 3649 12164 3652 12161
      3660 12170 3655 12155 3640 12143 3639 12151
      3615 12148 3613 12138 3597 12126 3594 12147
      3615 12167 3618 12167 3613 12157 3621 12149
      3620 12151 3620 12154 3620 12157 3636 12151

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

MTR

993 
WGUS76 KMTR 140359
FFSMTR

Flash Flood Statement
National Weather Service San Francisco CA
759 PM PST Mon Dec 13 2021

CAC053-140409-
/O.EXP.KMTR.FF.W.0016.000000T0000Z-211214T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monterey CA-
759 PM PST Mon Dec 13 2021

...FLASH FLOOD WARNING FOR THE DOLAN, CARMEL, RIVER, WILLOW BURN 
AREA WILL EXPIRE AT 8 PM PST THIS EVENING FOR SOUTHWESTERN MONTEREY 
COUNTY, HOWEVER MORE RAIN IS EXPECTED LATER TONIGHT...


The current warning will expire as there is a break in the rainfall. 
However more rain will likely fall over the burn scars later tonight.

A Flash Flood Watch remains in effect until 100 AM PST for a portion 
of northern California.

A Flood Watch remains in effect until 300 AM PST Tuesday for a 
portion of northern California.

LAT...LON 3645 12173 3643 12161 3649 12164 3652 12161
      3660 12170 3655 12155 3640 12143 3639 12151
      3615 12148 3613 12138 3597 12126 3594 12147
      3615 12167 3618 12167 3613 12157 3621 12149
      3620 12151 3620 12154 3620 12157 3636 12151

$$

ED

The office that day

Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 13, 4:29 AM PST	Areal Flood Advisory	MTR	San Mateo, Santa Clara, Santa Cruz	18 hr
Dec 13, 5:31 AM PST	Areal Flood Advisory	MTR	Alameda, Contra Costa, San Mateo, Santa Clara	7 hr
Dec 13, 9:14 AM PST	Areal Flood Advisory	MTR	City and County of San Francisco, San Mateo, Santa Clara, Santa Cruz	3 hr
Dec 13, 10:45 AM PST	Flash Flood Warning Considerable damage threat	MTR	San Mateo, Santa Cruz	60 min
Dec 13, 12:00 PM PST	Flood Watch	MTR	Alameda, Contra Costa, Marin, Monterey, Napa, San Benito and 5 more	13 hr
Dec 13, 1:26 PM PST	Areal Flood Advisory	MTR	San Mateo	11 hr
Dec 13, 2:42 PM PST	Areal Flood Warning	MTR	Santa Cruz	4 hr

Nearby

Flash Flood Warnings in California, 2021 Every 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.