Alert archive / California / Flash Flood Watches in 2021

Flash Flood Watch 1, NWS San Francisco Bay Area, CA

January 24, 20217 counties in California

NWS San Francisco Bay Area, CA issued this flash flood watch at Jan 24, 2021, 5:19 PM PST for 7 counties in California. It took effect at Jan 26, 2021, 4:00 PM PST. It was in force for 49 hr.

The area

The counties it named.

The facts

Issued
Jan 24, 2021, 5:19 PM PST (01:19 UTC)
In effect from
Jan 26, 2021, 4:00 PM PST
Expired
Jan 28, 2021, 5:00 PM PST
In force
49 hr
Issued by
NWS San Francisco Bay Area, CA
Flood severity
None

Counties Marin County, CA, Monterey County, CA, Napa County, CA, San Mateo County, CA, Santa Clara County, CA, Santa Cruz County, CA, Sonoma County, CA

The radar

The San Francisco radar (KMUX), 53 km from the middle of the area, began a volume at 01:21 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, 1.3 hours before the alert went out and 412 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 2021-01-25Temperature 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 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 2021-01-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -24 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1671 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-24 m²/s²
0-3 km storm-relative helicity
-30 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

046 
WGUS66 KMTR 250119
FFAMTR

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service San Francisco CA
519 PM PST Sun Jan 24 2021

CAZ505>507-509-512-517-251330-
/O.NEW.KMTR.FF.A.0001.210127T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal North Bay Including Point Reyes National Seashore-North Bay
Interior Valleys-North Bay Mountains-San Francisco Peninsula Coast-
Santa Cruz Mountains-Santa Lucia Mountains and Los Padres National
Forest-
Including the cities of Woodacre, Sausalito, Santa Rosa, Boulder 
Creek, Day Valley, Lagunitas-Forest Knolls, Angwin, Rohnert Park, 
San Rafael, Tamalpais-Homestead, South Santa Rosa, Pacifica, 
Petaluma, Napa, Novato, and Scotts Valley
519 PM PST Sun Jan 24 2021

...FLASH FLOOD WATCH IN EFFECT FROM TUESDAY AFTERNOON THROUGH 
THURSDAY AFTERNOON...

The National Weather Service in San Francisco has issued a

* Flash Flood Watch for a portion of western California, including 
  the following areas, Coastal North Bay Including Point Reyes 
  National Seashore, North Bay Interior Valleys, North Bay 
  Mountains, San Francisco Peninsula Coast, Santa Cruz Mountains and 
  Santa Lucia Mountains and Los Padres National Forest.

* From Tuesday afternoon through Thursday afternoon

* A moderate atmospheric river will impact the region Tuesday 
  through Thursday bringing prolonged periods of moderate to heavy 
  rain along with gusty south winds. The brunt of the storm is 
  forecast to occur between Tuesday evening through Wednesday.

* High confidence that thresholds for debris flows will be met for 
  the following 2020 burn scars: Meyers, Walbridge, Glass, 
  Hennessey, Woodward, CZU, Carmel/River, and Dolan.
  For non-burn scar areas, there could be rapid ponding of water in 
  urban areas, and low lying areas with poor drainage. We also 
  cannot rule out slides or wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders.

&&

$$

BB
13 follow-up statements
047 
WGUS66 KMTR 251312
FFAMTR

Flood Watch
National Weather Service San Francisco CA
512 AM PST Mon Jan 25 2021

CAZ505>507-509-512-517-252300-
/O.CON.KMTR.FF.A.0001.210127T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal North Bay Including Point Reyes National Seashore-North Bay
Interior Valleys-North Bay Mountains-San Francisco Peninsula Coast-
Santa Cruz Mountains-Santa Lucia Mountains and Los Padres National
Forest-
Including the cities of Woodacre, Sausalito, Santa Rosa, Boulder 
Creek, Day Valley, Lagunitas-Forest Knolls, Angwin, Rohnert Park, 
San Rafael, Tamalpais-Homestead, South Santa Rosa, Pacifica, 
Petaluma, Napa, Novato, and Scotts Valley
512 AM PST Mon Jan 25 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM TUESDAY AFTERNOON 
THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* A portion of western California, including the following areas, 
  Coastal North Bay Including Point Reyes National Seashore, North 
  Bay Interior Valleys, North Bay Mountains, San Francisco Peninsula 
  Coast, Santa Cruz Mountains and Santa Lucia Mountains and Los 
  Padres National Forest.

* From Tuesday afternoon through Thursday afternoon

* A moderate atmospheric river will impact the region Tuesday 
  through Thursday bringing prolonged periods of moderate to heavy 
  rain along with gusty south winds. The brunt of the storm is 
  forecast to occur between Tuesday evening through Wednesday.

* High confidence that thresholds for debris flows will be met for 
  the following 2020 burn scars: Meyers, Walbridge, Glass, 
  Hennessey, Woodward, CZU Lightning Complex, Carmel/River, and 
  Dolan.
  For non-burn scar areas, there could be rapid ponding of water in 
  urban areas, and low lying areas with poor drainage. We also 
  cannot rule out slides or wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders.

&&

$$

MM
778 
WGUS66 KMTR 252221
FFAMTR

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service San Francisco CA
221 PM PST Mon Jan 25 2021

CAZ511-260630-
/O.EXA.KMTR.FF.A.0001.210127T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
East Bay Hills and the Diablo Range-
Including the cities of Blackhawk
221 PM PST Mon Jan 25 2021

...FLASH FLOOD WATCH IN EFFECT FROM TUESDAY AFTERNOON THROUGH 
THURSDAY AFTERNOON...

The National Weather Service in San Francisco has expanded the

* Flash Flood Watch to include a portion of western California, 
  including the following area, East Bay Hills and the Diablo Range.

* From Tuesday afternoon through Thursday afternoon

* A moderate atmospheric river will impact the region Tuesday 
  through Thursday bringing prolonged periods of moderate to heavy 
  rain along with strong, potentially damaging southerly winds. The 
  brunt of the storm is forecast to occur between Tuesday evening 
  through Wednesday.

* High confidence that thresholds for debris flows will be met for 
  the following 2020 burn scars: SCU Lightning Complex. For non-burn 
  scar areas, there could be rapid ponding of water in urban areas, 
  and low lying areas with poor drainage. We also cannot rule out 
  slides or wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CAZ505>507-509-512-517-260630-
/O.CON.KMTR.FF.A.0001.210127T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal North Bay Including Point Reyes National Seashore-North Bay
Interior Valleys-North Bay Mountains-San Francisco Peninsula Coast-
Santa Cruz Mountains-Santa Lucia Mountains and Los Padres National
Forest-
Including the cities of Woodacre, Sausalito, Santa Rosa, Boulder 
Creek, Day Valley, Lagunitas-Forest Knolls, Angwin, Rohnert Park, 
San Rafael, Tamalpais-Homestead, South Santa Rosa, Pacifica, 
Petaluma, Napa, Novato, and Scotts Valley
221 PM PST Mon Jan 25 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM TUESDAY AFTERNOON 
THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* A portion of western California, including the following areas, 
  Coastal North Bay Including Point Reyes National Seashore, North 
  Bay Interior Valleys, North Bay Mountains, San Francisco Peninsula 
  Coast, Santa Cruz Mountains and Santa Lucia Mountains and Los 
  Padres National Forest.

* From Tuesday afternoon through Thursday afternoon

* A moderate atmospheric river will impact the region Tuesday 
  through Thursday bringing prolonged periods of moderate to heavy 
  rain along with strong, potentially damaging southerly winds. The 
  brunt of the storm is forecast to occur between Tuesday evening 
  through Wednesday.

* High confidence that thresholds for debris flows will be met for 
  the following 2020 burn scars: Meyers, Walbridge, Glass, 
  Hennessey, Woodward, CZU Lightning Complex, Carmel/River, and 
  Dolan. For non-burn scar areas, there could be rapid ponding of 
  water in urban areas, and low lying areas with poor drainage. We 
  also cannot rule out slides or wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

RGass
795 
WGUS66 KMTR 260607
FFAMTR

Flood Watch
National Weather Service San Francisco CA
1007 PM PST Mon Jan 25 2021

CAZ505>507-509-511-512-517-261700-
/O.CON.KMTR.FF.A.0001.210127T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal North Bay Including Point Reyes National Seashore-North Bay
Interior Valleys-North Bay Mountains-San Francisco Peninsula Coast-
East Bay Hills and the Diablo Range-Santa Cruz Mountains-Santa Lucia
Mountains and Los Padres National Forest-
Including the cities of Woodacre, Sausalito, Santa Rosa, Boulder 
Creek, Day Valley, Lagunitas-Forest Knolls, Blackhawk, Angwin, 
Rohnert Park, San Rafael, Tamalpais-Homestead, South Santa Rosa, 
Pacifica, Petaluma, Napa, Novato, and Scotts Valley
1007 PM PST Mon Jan 25 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM TUESDAY AFTERNOON 
THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* A portion of western California, including the following areas, 
  Coastal North Bay Including Point Reyes National Seashore, East 
  Bay Hills and the Diablo Range, North Bay Interior Valleys, North 
  Bay Mountains, San Francisco Peninsula Coast, Santa Cruz Mountains 
  and Santa Lucia Mountains and Los Padres National Forest.

* From Tuesday afternoon through Thursday afternoon

* A moderate atmospheric river will impact the region Tuesday 
  through Thursday bringing prolonged periods of moderate to heavy 
  rain along with strong, potentially damaging southerly winds. The 
  brunt of the storm is forecast to occur between Tuesday evening 
  through Wednesday.

* High confidence that thresholds for debris flows will be met for 
  the following 2020 burn scars: Meyers, Walbridge, Glass, 
  Hennessey, Woodward, CZU Lightning Complex, SCU Lightning Complex, 
  Carmel/River, and Dolan. For non-burn scar areas, there could be 
  rapid ponding of water in urban areas, and low lying areas with 
  poor drainage. We also cannot rule out slides or wash outs in 
  areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

MM
144 
WGUS66 KMTR 261843
FFAMTR

Flood Watch
National Weather Service San Francisco CA
1043 AM PST Tue Jan 26 2021

CAZ505>507-509-511-512-517-270500-
/O.CON.KMTR.FF.A.0001.210127T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal North Bay Including Point Reyes National Seashore-North Bay
Interior Valleys-North Bay Mountains-San Francisco Peninsula Coast-
East Bay Hills and the Diablo Range-Santa Cruz Mountains-Santa Lucia
Mountains and Los Padres National Forest-
Including the cities of Woodacre, Sausalito, Santa Rosa, Boulder 
Creek, Day Valley, Lagunitas-Forest Knolls, Blackhawk, Angwin, 
Rohnert Park, San Rafael, Tamalpais-Homestead, South Santa Rosa, 
Pacifica, Petaluma, Napa, Novato, and Scotts Valley
1043 AM PST Tue Jan 26 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM 4 PM PST THIS AFTERNOON 
THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* A portion of western California, including the following areas, 
  Coastal North Bay Including Point Reyes National Seashore, East 
  Bay Hills and the Diablo Range, North Bay Interior Valleys, North 
  Bay Mountains, San Francisco Peninsula Coast, Santa Cruz Mountains 
  and Santa Lucia Mountains and Los Padres National Forest.

* From 4 PM PST this afternoon through Thursday afternoon

* A moderate atmospheric river will impact the region today through 
  Thursday bringing prolonged periods of moderate to heavy rain 
  along with strong, potentially damaging southerly winds. The brunt 
  of the storm is forecast to occur between Tuesday evening through 
  Wednesday.

* High confidence that thresholds for debris flows will be met for 
  the following 2020 burn scars: Meyers, Walbridge, Glass, 
  Hennessey, Woodward, CZU Lightning Complex, SCU Lightning Complex, 
  Carmel/River, and Dolan. For non-burn scar areas, there could be 
  rapid ponding of water in urban areas, and low lying areas with 
  poor drainage. We also cannot rule out slides or wash outs in 
  areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CW
408 
WGUS66 KMTR 270438
FFAMTR

Flood Watch
National Weather Service San Francisco CA
838 PM PST Tue Jan 26 2021

CAZ505>507-509-511-512-517-271400-
/O.CON.KMTR.FF.A.0001.000000T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal North Bay Including Point Reyes National Seashore-North Bay
Interior Valleys-North Bay Mountains-San Francisco Peninsula Coast-
East Bay Hills and the Diablo Range-Santa Cruz Mountains-Santa Lucia
Mountains and Los Padres National Forest-
Including the cities of Woodacre, Sausalito, Santa Rosa, Boulder 
Creek, Day Valley, Lagunitas-Forest Knolls, Blackhawk, Angwin, 
Rohnert Park, San Rafael, Tamalpais-Homestead, South Santa Rosa, 
Pacifica, Petaluma, Napa, Novato, and Scotts Valley
838 PM PST Tue Jan 26 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* A portion of western California, including the following areas, 
  Coastal North Bay Including Point Reyes National Seashore, East 
  Bay Hills and the Diablo Range, North Bay Interior Valleys, North 
  Bay Mountains, San Francisco Peninsula Coast, Santa Cruz Mountains 
  and Santa Lucia Mountains and Los Padres National Forest.

* Through Thursday afternoon

* A moderate atmospheric river will impact the region today through 
  Thursday bringing prolonged periods of moderate to heavy rain 
  along with strong, potentially damaging southerly winds. The brunt 
  of the storm is forecast to impact the region tonight through 
  Wednesday.

* High confidence that thresholds for debris flows will be met for 
  the following 2020 burn scars: Meyers, Walbridge, Glass, 
  Hennessey, Woodward, CZU Lightning Complex, SCU Lightning Complex, 
  Carmel/River, and Dolan. For non-burn scar areas, there could be 
  rapid ponding of water in urban areas, and low lying areas with 
  poor drainage. We also cannot rule out slides or wash outs in 
  areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CW
612 
WGUS66 KMTR 271059
FFAMTR

Flood Watch
National Weather Service San Francisco CA
259 AM PST Wed Jan 27 2021

CAZ505>507-509-271200-
/O.CAN.KMTR.FF.A.0001.000000T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal North Bay Including Point Reyes National Seashore-North Bay
Interior Valleys-North Bay Mountains-San Francisco Peninsula Coast-
Including the cities of Woodacre, Sausalito, Santa Rosa, 
Lagunitas-Forest Knolls, Angwin, Rohnert Park, San Rafael, 
Tamalpais-Homestead, South Santa Rosa, Pacifica, Petaluma, Napa, and 
Novato
259 AM PST Wed Jan 27 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for a portion of Northern California, 
including the following areas, Coastal North Bay Including Point 
Reyes National Seashore, North Bay Interior Valleys, North Bay 
Mountains and San Francisco Peninsula Coast has been cancelled.

The Flood Watch is cancelled.

$$

CAZ511-512-517-271900-
/O.CON.KMTR.FF.A.0001.000000T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
East Bay Hills and the Diablo Range-Santa Cruz Mountains-Santa Lucia
Mountains and Los Padres National Forest-
Including the cities of Scotts Valley, Day Valley, Boulder Creek, 
and Blackhawk
259 AM PST Wed Jan 27 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* A portion of western California, including the following areas, 
  East Bay Hills and the Diablo Range, Santa Cruz Mountains and 
  Santa Lucia Mountains and Los Padres National Forest.

* Through Thursday afternoon

* Even though the period of heaviest rains have ended the 
  atmospheric river may stall over Monterey county and rotate 
  northward over the CZU and SCU Lightning Complex burn area later 
  tonight into early Thursday. More flash flood warnings may need to 
  be issued over the next 24 hours.

* Moderate to high confidence that thresholds for debris flows will 
  be met for the following 2020 burn scars: CZU Lightning Complex, 
  SCU Lightning Complex, Carmel/River, and Dolan. For non-burn scar 
  areas, there could be rapid ponding of water in urban areas, and 
  low lying areas with poor drainage. We also cannot rule out slides 
  or wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

RWW
549 
WGUS66 KMTR 271848
FFAMTR

Flood Watch
National Weather Service San Francisco CA
1048 AM PST Wed Jan 27 2021

CAZ511-512-517-280615-
/O.CON.KMTR.FF.A.0001.000000T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
East Bay Hills and the Diablo Range-Santa Cruz Mountains-Santa Lucia
Mountains and Los Padres National Forest-
Including the cities of Scotts Valley, Day Valley, Boulder Creek, 
and Blackhawk
1048 AM PST Wed Jan 27 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* A portion of western California, including the following areas, 
  East Bay Hills and the Diablo Range, Santa Cruz Mountains and 
  Santa Lucia Mountains and Los Padres National Forest.

* Through Thursday afternoon

* Even though the period of heaviest rains have ended the 
  atmospheric river may stall over Monterey county and rotate 
  northward over the CZU and SCU Lightning Complex burn area later 
  tonight into early Thursday. More flash flood warnings may need to 
  be issued over the next 24 hours.

* Moderate to high confidence that thresholds for debris flows will 
  be met for the following 2020 burn scars: CZU Lightning Complex, 
  SCU Lightning Complex, Carmel/River, and Dolan. For non-burn scar 
  areas, there could be rapid ponding of water in urban areas, and 
  low lying areas with poor drainage. We also cannot rule out slides 
  or wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CW
790 
WGUS66 KMTR 271919
FFAMTR

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service San Francisco CA
1119 AM PST Wed Jan 27 2021

CAZ507-280615-
/O.EXA.KMTR.FF.A.0001.000000T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
North Bay Mountains-
Including the cities of Woodacre, Lagunitas-Forest Knolls, and Angwin
1119 AM PST Wed Jan 27 2021

...FLASH FLOOD WATCH FOR THE HENNESSEY PORTION OF THE LNU LIGHTNING 
COMPLEX BURN AREA IN EFFECT THROUGH THURSDAY AFTERNOON...

The National Weather Service in San Francisco has expanded the

* Flash Flood Watch to include a portion of western California, 
  including the following area, North Bay Mountains.

* Through Thursday afternoon

* National Weather Service Meteorologists are forecasting moderate 
  to heavy rainfall over the Hennessey portion of the LNU Lightning 
  Complex burn area, which may lead to flash flooding and debris 
  flows.

* Periods of light to moderate rainfall are expected through the day 
  today over the Hennessey portion of the LNU Lightning Complex burn 
  area. Rain rates and intensities are expected to increase as a 
  secondary boundary sets up over the burn area by mid to late 
  evening. Moderate to heavy rainfall is expected to accompany 
  embedded thunderstorms that develop along the boundary this 
  evening through Thursday afternoon. Residents near the Hennessey 
  portion of the LNU Lightning Complex burn area should prepare for 
  potential flooding impacts. Be sure to stay up to date with 
  information from local authorities.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CAZ511-512-517-280615-
/O.CON.KMTR.FF.A.0001.000000T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
East Bay Hills and the Diablo Range-Santa Cruz Mountains-Santa Lucia
Mountains and Los Padres National Forest-
Including the cities of Scotts Valley, Day Valley, Boulder Creek, 
and Blackhawk
1119 AM PST Wed Jan 27 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* A portion of western California, including the following areas, 
  East Bay Hills and the Diablo Range, Santa Cruz Mountains and 
  Santa Lucia Mountains and Los Padres National Forest.

* Through Thursday afternoon

* Even though the period of heaviest rains have ended the 
  atmospheric river may stall over Monterey county and rotate 
  northward over the CZU and SCU Lightning Complex burn area later 
  tonight into early Thursday. More flash flood warnings may need to 
  be issued over the next 24 hours.

* Moderate to high confidence that thresholds for debris flows will 
  be met for the following 2020 burn scars: CZU Lightning Complex, 
  SCU Lightning Complex, Carmel/River, and Dolan. For non-burn scar 
  areas, there could be rapid ponding of water in urban areas, and 
  low lying areas with poor drainage. We also cannot rule out slides 
  or wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CW
386 
WGUS66 KMTR 271940
FFAMTR

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service San Francisco CA
1140 AM PST Wed Jan 27 2021

CAZ506-280615-
/O.EXA.KMTR.FF.A.0001.000000T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
North Bay Interior Valleys-
Including the cities of Rohnert Park, Santa Rosa, San Rafael, South 
Santa Rosa, Petaluma, Napa, and Novato
1140 AM PST Wed Jan 27 2021

...FLASH FLOOD WATCH FOR THE WALBRIDGE PORTION OF THE LNU LIGHTNING 
COMPLEX BURN AREA IN EFFECT THROUGH THURSDAY AFTERNOON...

The National Weather Service in San Francisco has expanded the

* Flash Flood Watch to include a portion of western California, 
  including the following area, North Bay Interior Valleys.

* Through Thursday afternoon

* National Weather Service Meteorologists are forecasting moderate 
  to heavy rainfall over the Walbridge portion of the LNU Lightning 
  Complex burn area, which may lead to flash flooding and debris 
  flows.

* Periods of light to moderate rainfall are expected through the day 
  today over the Walbridge portion of the LNU Lightning Complex burn 
  area. Rain rates and intensities are expected to increase as a 
  secondary boundary sets up over the burn area by mid to late 
  evening. Moderate to heavy rainfall is expected to accompany 
  embedded thunderstorms that develop along the boundary this 
  evening through Thursday afternoon. Residents near the Walbridge 
  portion of the LNU Lightning Complex burn area should prepare for 
  potential flooding impacts. Be sure to stay up to date with 
  information from local authorities.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CAZ511-512-517-280615-
/O.CON.KMTR.FF.A.0001.000000T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
East Bay Hills and the Diablo Range-Santa Cruz Mountains-Santa Lucia
Mountains and Los Padres National Forest-
Including the cities of Scotts Valley, Day Valley, Boulder Creek, 
and Blackhawk
1140 AM PST Wed Jan 27 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* A portion of western California, including the following areas, 
  East Bay Hills and the Diablo Range, Santa Cruz Mountains and 
  Santa Lucia Mountains and Los Padres National Forest.

* Through Thursday afternoon

* Even though the period of heaviest rains have ended the 
  atmospheric river may stall over Monterey county and rotate 
  northward over the CZU and SCU Lightning Complex burn area later 
  tonight into early Thursday. More flash flood warnings may need to 
  be issued over the next 24 hours.

* Moderate to high confidence that thresholds for debris flows will 
  be met for the following 2020 burn scars: CZU Lightning Complex, 
  SCU Lightning Complex, Carmel/River, and Dolan. For non-burn scar 
  areas, there could be rapid ponding of water in urban areas, and 
  low lying areas with poor drainage. We also cannot rule out slides 
  or wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CAZ507-280615-
/O.CON.KMTR.FF.A.0001.000000T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
North Bay Mountains-
Including the cities of Woodacre, Lagunitas-Forest Knolls, and Angwin
1140 AM PST Wed Jan 27 2021

...FLASH FLOOD WATCH FOR THE HENNESSEY PORTION OF THE LNU LIGHTNING 
COMPLEX BURN AREA REMAINS IN EFFECT THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* The Walbridge portion of the LNU Lightning Complex burn area in a 
  portion of western California, including the following area, North 
  Bay Mountains.

* Through Thursday afternoon

* National Weather Service Meteorologists are forecasting moderate 
  to heavy rainfall over the Hennessey portion of the LNU Lightning 
  Complex burn area, which may lead to flash flooding and debris 
  flows.

* Periods of light to moderate rainfall are expected through the day 
  today over the Hennessey portion of the LNU Lightning Complex burn 
  area. Rain rates and intensities are expected to increase as a 
  secondary boundary sets up over the burn area by mid to late 
  evening. Moderate to heavy rainfall is expected to accompany 
  embedded thunderstorms that develop along the boundary this 
  evening through Thursday afternoon. Residents near the Hennessey 
  portion of the LNU Lightning Complex burn area should prepare for 
  potential flooding impacts. Be sure to stay up to date with 
  information from local authorities.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CW
140 
WGUS66 KMTR 272026
FFAMTR

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service San Francisco CA
1226 PM PST Wed Jan 27 2021

CAZ506-507-280600-
/O.EXT.KMTR.FF.A.0001.000000T0000Z-210129T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
North Bay Interior Valleys-North Bay Mountains-
Including the cities of Rohnert Park, Santa Rosa, Lagunitas-Forest 
Knolls, Angwin, San Rafael, Woodacre, South Santa Rosa, Petaluma, 
Napa, and Novato
1226 PM PST Wed Jan 27 2021

...FLASH FLOOD WATCH FOR THE 2020 BURN AREAS IN NAPA AND SONOMA 
COUNTIES NOW IN EFFECT THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch is now in effect for

* A portion of western California, including the following areas, 
  North Bay Interior Valleys and North Bay Mountains.

* Through Thursday afternoon

* National Weather Service Meteorologists are forecasting periods of 
  moderate to heavy rainfall over the 2020 Burn Areas in Napa and 
  Sonoma Counties, which may lead to flash flooding and debris flows.

* Periods of light to moderate rainfall are expected through the day 
  today over the 2020 Burn Areas in Napa and Sonoma Counties. Rain 
  rates and intensities are expected to increase as a secondary 
  boundary sets up over the burn area by mid to late evening. 
  Moderate to heavy rainfall is expected to accompany embedded 
  thunderstorms that develop along the boundary this evening through 
  Thursday afternoon. Residents near the 2020 Burn Areas in Napa and 
  Sonoma Counties should prepare for potential flooding impacts. Be 
  sure to stay up to date with information from local authorities.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CAZ511-512-517-280600-
/O.CON.KMTR.FF.A.0001.000000T0000Z-210129T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
East Bay Hills and the Diablo Range-Santa Cruz Mountains-Santa Lucia
Mountains and Los Padres National Forest-
Including the cities of Scotts Valley, Day Valley, Boulder Creek, 
and Blackhawk
1226 PM PST Wed Jan 27 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* A portion of western California, including the following areas, 
  East Bay Hills and the Diablo Range, Santa Cruz Mountains and 
  Santa Lucia Mountains and Los Padres National Forest.

* Through Thursday afternoon

* Even though the period of heaviest rains have ended the 
  atmospheric river may stall over Monterey county and rotate 
  northward over the CZU and SCU Lightning Complex burn area later 
  tonight into early Thursday. More flash flood warnings may need to 
  be issued over the next 24 hours.

* Moderate to high confidence that thresholds for debris flows will 
  be met for the following 2020 burn scars: CZU Lightning Complex, 
  SCU Lightning Complex, Carmel/River, and Dolan. For non-burn scar 
  areas, there could be rapid ponding of water in urban areas, and 
  low lying areas with poor drainage. We also cannot rule out slides 
  or wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CW
593 
WGUS66 KMTR 280606
FFAMTR

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service San Francisco CA
1006 PM PST Wed Jan 27 2021

CAZ511-512-517-281815-
/O.EXT.KMTR.FF.A.0001.000000T0000Z-210129T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
East Bay Hills and the Diablo Range-Santa Cruz Mountains-Santa Lucia
Mountains and Los Padres National Forest-
Including the cities of Scotts Valley, Day Valley, Boulder Creek, 
and Blackhawk
1006 PM PST Wed Jan 27 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch is now in effect for

* A portion of western California, including the following areas, 
  East Bay Hills and the Diablo Range, Santa Cruz Mountains and 
  Santa Lucia Mountains and Los Padres National Forest.

* Through Thursday afternoon

* An atmospheric river will continue to produce moderate to heavy 
  rain across Monterey County through Wednesday Night. Farther 
  north, showers and possible thunderstorms will produce brief heavy 
  rain Wednesday night. Scattered showers and isolated thunderstorms 
  will continue through Thursday.

* Moderate confidence that thresholds for debris flows will be met 
  for the following 2020 burn scars: CZU Lightning Complex, SCU 
  Lightning Complex, Carmel/River, and Dolan. For non-burn scar 
  areas, there could be ponding of water in urban areas, and low 
  lying areas with poor drainage. We also cannot rule out slides or 
  wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CAZ506-507-281815-
/O.CON.KMTR.FF.A.0001.000000T0000Z-210129T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
North Bay Interior Valleys-North Bay Mountains-
Including the cities of Rohnert Park, Santa Rosa, Lagunitas-Forest 
Knolls, Angwin, San Rafael, Woodacre, South Santa Rosa, Petaluma, 
Napa, and Novato
1006 PM PST Wed Jan 27 2021

...FLASH FLOOD WATCH FOR THE 2020 BURN AREAS IN NAPA AND SONOMA 
COUNTIES REMAINS IN EFFECT THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* The 2020 Burn Areas in Napa and Sonoma Counties in a portion of 
  western California, including the following areas, North Bay 
  Interior Valleys and North Bay Mountains.

* Through Thursday afternoon

* Showers and isolated thunderstorms are forecast Wednesday night 
  through Thursday. These showers and thunderstorms may result in 
  brief periods of intense rainfall which could trigger debris flows 
  or flash flooding on the burn scars.

* Rain rates and intensities are expected to increase as showers and 
  isolated thunderstorms increase across the burn areas overnight. 
  Brief heavy rain is possible with showers and thunderstorms 
  through Thursday afternoon. Residents near the 2020 Burn Areas in 
  Napa and Sonoma Counties should prepare for potential flooding 
  impacts. The burn scars include the Hennessey, the Walbridge, and 
  the Glass. Be sure to stay up to date with information from local 
  authorities.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

DD
868 
WGUS66 KMTR 281805
FFAMTR

Flood Watch
National Weather Service San Francisco CA
1005 AM PST Thu Jan 28 2021

CAZ511-512-517-290100-
/O.CON.KMTR.FF.A.0001.000000T0000Z-210129T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
East Bay Hills and the Diablo Range-Santa Cruz Mountains-Santa Lucia
Mountains and Los Padres National Forest-
Including the cities of Scotts Valley, Day Valley, Boulder Creek, 
and Blackhawk
1005 AM PST Thu Jan 28 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 5 PM PST THIS 
AFTERNOON...

The Flash Flood Watch continues for

* A portion of western California, including the following areas, 
  East Bay Hills and the Diablo Range, Santa Cruz Mountains and 
  Santa Lucia Mountains and Los Padres National Forest.

* Until 5 PM PST this afternoon

* National Weather Service Meteorologists are forecasting scattered 
  rain showers with the potential for isolated thunderstorms through 
  Thursday afternoon, which may lead to flash flooding and debris 
  flows.

* These showers and/or thunderstorms may briefly meet thresholds for 
  debris flows over the following 2020 burn scars: CZU Lightning 
  Complex, SCU Lightning Complex, Carmel/River, and Dolan. For 
  non-burn scar areas, there could be ponding of water in urban 
  areas, and low lying areas with poor drainage. We also cannot rule 
  out slides or wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

CAZ506-507-290100-
/O.CON.KMTR.FF.A.0001.000000T0000Z-210129T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
North Bay Interior Valleys-North Bay Mountains-
Including the cities of Rohnert Park, Santa Rosa, Lagunitas-Forest 
Knolls, Angwin, San Rafael, Woodacre, South Santa Rosa, Petaluma, 
Napa, and Novato
1005 AM PST Thu Jan 28 2021

...FLASH FLOOD WATCH FOR THE 2020 BURN AREAS IN NAPA AND SONOMA 
COUNTIES REMAINS IN EFFECT UNTIL 5 PM PST THIS AFTERNOON...

The Flash Flood Watch continues for

* The 2020 Burn Areas in Napa and Sonoma Counties in a portion of 
  western California, including the following areas, North Bay 
  Interior Valleys and North Bay Mountains.

* Until 5 PM PST this afternoon

* National Weather Service Meteorologists are forecasting scattered 
  rain showers with the potential for isolated thunderstorms through 
  Thursday afternoon, which may lead to flash flooding and debris 
  flows.

* These showers and/or thunderstorms may briefly meet thresholds for 
  debris flows over the 2020 Burn Areas in Napa and Sonoma Counties. 
  For non-burn scar areas, there could be ponding of water in urban 
  areas, and low lying areas with poor drainage. We also cannot rule 
  out slides or wash outs in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you live near or on a burn scar: make sure you are signed up for 
your county's reverse 911 or other alert system and have a "go bag" 
ready. Monitor the weather for forecast updates and heed local 
official orders. Do not cross flooded roadways, turn around don't 
drown.

&&

$$

RGass
663 
WGUS66 KMTR 290058
FFAMTR

Flood Watch
National Weather Service San Francisco CA
458 PM PST Thu Jan 28 2021

CAZ506-507-511-512-517-290200-
/O.EXP.KMTR.FF.A.0001.000000T0000Z-210129T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
North Bay Interior Valleys-North Bay Mountains-East Bay Hills and
the Diablo Range-Santa Cruz Mountains-Santa Lucia Mountains and Los
Padres National Forest-
Including the cities of Scotts Valley, Rohnert Park, Santa Rosa, 
Boulder Creek, Day Valley, Lagunitas-Forest Knolls, Blackhawk, 
Angwin, San Rafael, Woodacre, South Santa Rosa, Petaluma, Napa, and 
Novato
458 PM PST Thu Jan 28 2021

...FLASH FLOOD WATCH FOR THE 2020 BURN AREAS WILL EXPIRE AT 5 PM PST 
THIS AFTERNOON...

The Flash Flood Watch for a portion of western California, including 
the following areas, East Bay Hills and the Diablo Range, North Bay 
Interior Valleys, North Bay Mountains, Santa Cruz Mountains and 
Santa Lucia Mountains and Los Padres National Forest will expire AT 
5 PM PST this afternoon.

The Flood Watch will be allowed to expire at 5 PM PST. Flooding and 
debris flows are no longer expected to pose a threat. However, brief 
heavy rain is still possible with showers and possible thunderstorms 
through tonight. Please continue to heed remaining road closures.

$$

DD

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 25, 2:55 AM PSTHigh Wind WatchMTRAlameda, Contra Costa, Marin, Monterey, Napa, San Benito and 5 more12 hr
Jan 25, 1:42 PM PSTStorm WatchMTR13 hr
Jan 25, 2:42 PM PSTFreeze WarningMTRAlameda, Contra Costa, Marin, Monterey, Napa, Santa Clara and 1 more17 hr
Jan 25, 2:42 PM PSTHigh Wind WarningMTRMarin, Monterey, City and County of San Francisco, San Mateo, Santa Clara, Santa Cruz and 1 more45 hr
Jan 25, 2:42 PM PSTWind AdvisoryMTRAlameda, Contra Costa, Marin, Monterey, Napa, San Benito and 3 more61 hr

Nearby

Flash Flood Watches in California, 2021Every flash flood watch 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.