Alert archive / California / Flash Flood Warnings in 2021

Flash Flood Warning 4, NWS San Francisco Bay Area, CA

January 27, 2021Monterey County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 27, 2021, 1:38 AM PST for Monterey County, California. It was in force for 14 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
Jan 27, 2021, 1:38 AM PST (09:38 UTC)
Expired
Jan 27, 2021, 3:30 PM PST
In force
14 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), 124 km from the middle of the area, began a volume at 09:40 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 00:00Z, 9.6 hours before the alert went out and 175 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 00:00Z on 2021-01-27Temperature 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 00:00Z on 2021-01-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 square meters per square second.1939587897Sfc1 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
1284 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
77 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

621 
WGUS56 KMTR 270938
FFWMTR
CAC053-271730-
/O.NEW.KMTR.FF.W.0004.210127T0938Z-210127T1730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
138 AM PST Wed Jan 27 2021

The National Weather Service in San Francisco has issued a

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

* Until 930 AM PST Wednesday.

* At 138 AM PST, Doppler radar and automated rain gauges indicated 
  heavy rain falling over the Dolan Burn Area. Between 1 and 1.5 
  inches of rain have fallen. Flash flooding is ongoing or expected 
  to begin shortly.

Excessive rainfall over the burn area will result in debris flow 
moving through the Dolan Fire burn area. 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 Burn Area.

  SOURCE...Doppler radar and automated gauges.

  IMPACT...Life threatening flash flooding of areas in and around
           the Dolan Burn Area.

* Some locations that will experience flash flooding include...
  Highway 1, Lucia and the Esalen Institute.

This is a life threatening situation for people in or near the Dolan 
Fire burn area. Some drainage basins impacted include...Stony 
Creek...Nacimiento River...San Antonio River...Big Creek North Fork.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life-threatening situation.  If you observe movement of 
soils move to higher ground immediately.

&&

LAT...LON 3597 12145 3594 12147 3601 12150 3605 12159
      3618 12167 3618 12163 3613 12159 3621 12149
      3620 12147 3620 12148 3617 12145 3618 12148
      3615 12148 3615 12142 3613 12138 3600 12126
      3597 12126 3596 12135

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...3-6 INCHES IN 8 HOURS 

$$

RWW
6 follow-up statements
735 
WGUS76 KMTR 271251
FFSMTR

Flash Flood Statement
National Weather Service San Francisco CA
451 AM PST Wed Jan 27 2021

CAC053-271730-
/O.CON.KMTR.FF.W.0004.000000T0000Z-210127T1730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monterey CA-
451 AM PST Wed Jan 27 2021

...FLASH FLOOD WARNING FOR THE DOLAN BURN AREA REMAINS IN EFFECT 
UNTIL 930 AM PST THIS MORNING FOR SOUTHWESTERN MONTEREY COUNTY...

At 451 AM PST, Doppler radar and automated rain gauges indicated 
that heavy rain was falling over the Dolan Burn Area. Between 2 and 
4 inches of rain have fallen. Flash flooding is ongoing or expected 
to begin shortly.

Excessive rainfall over the burn area will result in debris flow 
moving through the Dolan Fire burn area. 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 Burn Area.

SOURCE...Doppler radar and automated gauges.

IMPACT...Life threatening flash flooding of areas in and around
         the Dolan Burn Area.

Some locations that will experience flash flooding include...
  Highway 1, Lucia and the Esalen Institute.

This is a life threatening situation for people in or near the Dolan 
Fire burn area. Some drainage basins impacted include...Stony 
Creek...Nacimiento River...San Antonio River...Big Creek North Fork.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life-threatening situation.  If you observe movement of 
soils move to higher ground immediately.

&&

LAT...LON 3597 12145 3594 12147 3601 12150 3605 12159
      3618 12167 3618 12163 3613 12159 3621 12149
      3620 12147 3620 12148 3617 12145 3618 12148
      3615 12148 3615 12142 3613 12138 3600 12126
      3597 12126 3596 12135

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...2-4 INCHES IN 6 HOURS 

$$

RWW
756 
WGUS76 KMTR 271552
FFSMTR

Flash Flood Statement
National Weather Service San Francisco CA
752 AM PST Wed Jan 27 2021

CAC053-271730-
/O.CON.KMTR.FF.W.0004.000000T0000Z-210127T1730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monterey CA-
752 AM PST Wed Jan 27 2021

...FLASH FLOOD WARNING FOR THE DOLAN BURN AREA REMAINS IN EFFECT 
UNTIL 930 AM PST THIS MORNING FOR SOUTHWESTERN MONTEREY COUNTY...

At 752 AM PST, Doppler radar and automated rain gauges indicated 
that heavy rain was falling over the Dolan Burn Area. Between 2 and 
5 inches of rain have fallen. Flash flooding is ongoing or expected 
to begin shortly.

Excessive rainfall over the burn area will result in debris flow 
moving through the Dolan Fire burn area. 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 Burn Area.

SOURCE...Doppler radar and automated gauges.

IMPACT...Life threatening flash flooding of areas in and around
         the Dolan Burn Area.

Some locations that will experience flash flooding include...
  Lucia and Esalen Institute.

This is a life threatening situation for people in or near the Dolan 
Fire burn area. Some drainage basins impacted include...Stony 
Creek...Nacimiento River...San Antonio River...Big Creek North Fork.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life-threatening situation.  If you observe movement of 
soils move to higher ground immediately.

&&

LAT...LON 3597 12145 3594 12147 3601 12150 3605 12159
      3618 12167 3618 12163 3613 12159 3621 12149
      3620 12147 3620 12148 3617 12145 3618 12148
      3615 12148 3615 12142 3613 12138 3600 12126
      3597 12126 3596 12135

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...2.5-4.5 INCHES IN 6 HOURS 

$$

Palmer
201 
WGUS56 KMTR 271721
FFWMTR
CAC053-271930-
/O.EXT.KMTR.FF.W.0004.000000T0000Z-210127T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
921 AM PST Wed Jan 27 2021

The National Weather Service in San Francisco has extended the

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

* Until 1130 AM PST.

* At 921 AM PST, Doppler radar and automated rain gauges indicated 
  heavy rain falling over the Dolan Burn Area. Between 3 and 5 
  inches of rain have fallen. Flash flooding is ongoing or expected 
  to begin shortly.

Excessive rainfall over the burn area will result in debris flow 
moving through the Dolan Fire burn area. 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 Burn Area.

  SOURCE...Doppler radar and automated gauges.

  IMPACT...Life threatening flash flooding of areas in and around
           the Dolan Burn Area.

* Some locations that will experience flash flooding include...
  Lucia and Esalen Institute.

This is a life threatening situation for people in or near the Dolan 
Fire burn area. Some drainage basins impacted include...Stony 
Creek...Nacimiento River...San Antonio River...Big Creek North Fork.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life-threatening situation.  If you observe movement of 
soils move to higher ground immediately.

&&

LAT...LON 3597 12145 3594 12147 3601 12150 3605 12159
      3618 12167 3618 12163 3613 12159 3621 12149
      3620 12147 3620 12148 3617 12145 3618 12148
      3615 12148 3615 12142 3613 12138 3600 12126
      3597 12126 3596 12135

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...2-5 INCHES IN 6 HOURS 

$$

Palmer
696 
WGUS56 KMTR 271917
FFWMTR
CAC053-272130-
/O.EXT.KMTR.FF.W.0004.000000T0000Z-210127T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
1117 AM PST Wed Jan 27 2021

The National Weather Service in San Francisco has extended the

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

* Until 130 PM PST.

* At 1117 AM PST, Doppler radar and automated rain gauges indicated 
  the atmospheric river stalled over the Dolan Burn Area, with 
  moderate to heavy rain falling. Between 3 and 5.5 inches of rain 
  have already fallen. The public is reporting of a mud slide across 
  Highway 1 at mile marker 27. Therefore, flash flooding is ongoing 
  and will likely continue.

Excessive rainfall over the burn area will result in debris flow 
moving through the Dolan Fire burn area. 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 Burn Area.

  SOURCE...Doppler radar and automated gauges.

  IMPACT...Life threatening flash flooding of areas in and around
           the Dolan Burn Area.

* Some locations that will experience flash flooding include...
  Lucia and Esalen Institute.

This is a life threatening situation for people in or near the Dolan 
Fire burn area. Some drainage basins impacted include...Stony 
Creek...Nacimiento River...San Antonio River...Big Creek North Fork.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life-threatening situation.  If you observe movement of 
soils move to higher ground immediately.

&&

LAT...LON 3597 12145 3594 12147 3601 12150 3605 12159
      3618 12167 3618 12163 3613 12159 3621 12149
      3620 12147 3620 12148 3617 12145 3618 12148
      3615 12148 3615 12142 3613 12138 3600 12126
      3597 12126 3596 12135

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...2-5 INCHES IN 6 HOURS 

$$

Palmer
783 
WGUS56 KMTR 272116
FFWMTR
CAC053-272330-
/O.EXT.KMTR.FF.W.0004.000000T0000Z-210127T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
116 PM PST Wed Jan 27 2021

The National Weather Service in San Francisco has extended the

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

* Until 330 PM PST.

* At 116 PM PST, Doppler radar and automated rain gauges indicated 
  moderate to heavy rain falling over the Dolan Burn Area. Between 3 
  and 6 inches of rain have fallen. The public is reporting of a mud 
  slide across Highway 1 at mile marker 27. Therefore, flash 
  flooding is ongoing and will likely continue.

Excessive rainfall over the burn area will result in debris flow 
moving through the Dolan Fire burn area. 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 Burn Area.

  SOURCE...Doppler radar and automated gauges.

  IMPACT...Life threatening flash flooding of areas in and around
           the Dolan Burn Area.

* Some locations that will experience flash flooding include...
  Lucia and Esalen Institute.

This is a life threatening situation for people in or near the Dolan 
Fire burn area. Some drainage basins impacted include...Stony 
Creek...Nacimiento River...San Antonio River...Big Creek North Fork.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life-threatening situation.  If you observe movement of 
soils move to higher ground immediately.

&&

LAT...LON 3597 12145 3594 12147 3601 12150 3605 12159
      3618 12167 3618 12163 3613 12159 3621 12149
      3620 12147 3620 12148 3617 12145 3618 12148
      3615 12148 3615 12142 3613 12138 3600 12126
      3597 12126 3596 12135

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...0.5-2 INCHES IN 6 HOURS 

$$

Palmer
667 
WGUS76 KMTR 272324
FFSMTR

Flash Flood Statement
National Weather Service San Francisco CA
324 PM PST Wed Jan 27 2021

CAC053-272334-
/O.EXP.KMTR.FF.W.0004.000000T0000Z-210127T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monterey CA-
324 PM PST Wed Jan 27 2021

...FLASH FLOOD WARNING FOR THE DOLAN BURN AREA WILL EXPIRE AT 330 PM 
PST THIS AFTERNOON FOR SOUTHWESTERN MONTEREY COUNTY...

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

A Flash Flood Watch remains in effect until 400 PM PST Thursday for 
a portion of western California.

LAT...LON 3597 12145 3594 12147 3601 12150 3605 12159
      3618 12167 3618 12163 3613 12159 3621 12149
      3620 12147 3620 12148 3617 12145 3618 12148
      3615 12148 3615 12142 3613 12138 3600 12126
      3597 12126 3596 12135

$$

MM

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 26, 9:39 PM PSTFlash Flood Warning Considerable damage threatMTRSonoma81 min
Jan 26, 10:22 PM PSTAreal Flood AdvisoryMTRMarin, Napa, Sonoma4 hr
Jan 26, 10:56 PM PSTFlash Flood Warning Considerable damage threatMTRSan Mateo, Santa Cruz4 hr
Jan 26, 11:18 PM PSTAreal Flood AdvisoryMTRAlameda, City and County of San Francisco, San Mateo, Santa Clara4 hr
Jan 26, 11:46 PM PSTSpecial Marine WarningMTR14 min
Jan 27, 1:31 AM PSTFlash Flood Warning Considerable damage threatMTRMonterey3 hr
Jan 27, 1:45 AM PSTFlash Flood Warning Considerable damage threatMTRMonterey3 hr
Jan 27, 2:06 AM PSTSpecial Marine WarningMTR24 min
Jan 27, 2:18 AM PSTAreal Flood AdvisoryMTRMonterey, Santa Cruz117 min
Jan 27, 2:23 AM PSTGale WarningMTR3 hr
Jan 27, 2:23 AM PSTSmall Craft AdvisoryMTR55 hr
Jan 27, 5:27 AM PSTGale WarningMTR21 hr
Jan 27, 12:03 PM PSTFlash Flood Warning Considerable damage threatMTRMonterey3 hr
Jan 27, 12:05 PM PSTFlash Flood WarningMTRMonterey3 hr
Jan 27, 12:33 PM PSTFlash Flood WarningMTRSan Mateo, Santa Cruz6 hr
Jan 27, 12:53 PM PSTSpecial Marine WarningMTR52 min
Jan 27, 2:11 PM PSTAreal Flood AdvisoryMTRAlameda, Monterey, San Benito, San Mateo, Santa Clara, Santa Cruz5 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.