Alert archive / California / Flood Watches in 2021

Flood Watch 1, NWS San Diego, CA

December 13, 20214 counties in California

NWS San Diego, CA issued this flood watch at Dec 13, 2021, 10:42 AM PST for 4 counties in California. It took effect at Dec 14, 2021, 6:00 AM PST. It was in force for 15 hr.

The area

The counties it named.

The facts

Issued
Dec 13, 2021, 10:42 AM PST (18:42 UTC)
In effect from
Dec 14, 2021, 6:00 AM PST
Expired
Dec 14, 2021, 9:00 PM PST
In force
15 hr
Issued by
NWS San Diego, CA
Flood severity
None

Counties Orange County, CA, Riverside County, CA, San Bernardino County, CA, San Diego County, CA

The nearest sounding before it

San Diego, CA (KNKX), launched 12:00Z, 6.7 hours before the alert went out and 124 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, San Diego, CA at 12:00Z on 2021-12-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 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, San Diego, CA at 12:00Z on 2021-12-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.19395878Sfc1 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
8 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
795 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
133 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

204 
WGUS66 KSGX 131842
FFASGX

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service San Diego CA
1042 AM PST Mon Dec 13 2021

CAZ043-048-050-055>058-060-552-554-140245-
/O.NEW.KSGX.FA.A.0001.211214T1400Z-211215T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Diego County Coastal Areas-San Bernardino and Riverside County
Valleys-The Inland Empire-San Diego County Valleys-San Bernardino
County Mountains-Riverside County Mountains-Santa Ana Mountains and
Foothills-San Diego County Mountains-Apple and Lucerne Valleys-
Orange County Coastal Areas-Orange County Inland Areas-
Including the cities of Vista, Ontario, Santee, Idyllwild-Pine Cove, 
Fontana, Garden Grove, Fullerton, Lucerne Valley, Apple Valley, 
Hesperia, Santa Ana, National City, Riverside, Poway, Big Bear Lake, 
Oceanside, Big Bear City, San Diego, Lake Arrowhead, Irvine, El 
Cajon, Newport Beach, Escondido, Chula Vista, Crestline, San 
Clemente, Wrightwood, Corona, Anaheim, Huntington Beach, 
Victorville, San Bernardino, Moreno Valley, Mission Viejo, Laguna 
Beach, Julian, Pine Valley, Orange, Costa Mesa, La Mesa, Encinitas, 
Running Springs, San Marcos, Carlsbad, and Rancho Cucamonga
1042 AM PST Mon Dec 13 2021

...FLOOD WATCH IN EFFECT FROM TUESDAY MORNING THROUGH TUESDAY 
EVENING...

* WHAT...Flash flooding on Tuesday is possible due to excessive 
  rainfall through the day with isolated afternoon thunderstorms. 
  Rainfall rates of 0.50-0.60 inches per hour expected Tuesday. 
  Higher rainfall rates are expected on coastal mountain slopes, 
  particularly the San Bernardino Mountains, with rainfall rates of 
  0.75 inches an hour expected.

* WHERE...A portion of Southern California, including the following 
  areas, Apple and Lucerne Valleys, Orange County Coastal Areas, 
  Orange County Inland Areas, Riverside County Mountains below 5000 
  feet, San Bernardino County Mountains below 5000 feet, San 
  Bernardino and Riverside County Valleys-The Inland Empire, San 
  Diego County Coastal Areas, San Diego County Mountains below 5000 
  feet, San Diego County Valleys and Santa Ana Mountains and 
  Foothills. This Watch includes the Apple, El Dorado and Bond burn 
  scars.

* WHEN...From Tuesday morning through Tuesday evening.

* IMPACTS...Excessive runoff may result in flooding of rivers, 
  creeks, streams, and other low-lying and flood-prone locations. 
  Debris flows and flash flooding are possible near recent burn 
  scars, including the Apple, El Dorado and Bond burn scars.

* ADDITIONAL DETAILS...
  - A winter storm will bring significant precipitation to the
    area. Forecast rainfall amounts across the area include 1-1.5
    inches west of the mountains, 2-3 inches along the San Diego
    and Riverside county mountains below 5000 feet, 2-5+ inches
    below 5000 feet in the San Bernardino mountains, and
    0.50-1.25 inches in the High Desert.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood 
Warnings. Those living in areas prone to flooding should be prepared 
to take action should flooding develop.

&&

$$

CO
4 follow-up statements
872 
WGUS66 KSGX 132126
FFASGX

Flood Watch
National Weather Service San Diego CA
126 PM PST Mon Dec 13 2021

CAZ043-048-050-055>058-060-552-554-140615-
/O.CON.KSGX.FA.A.0001.211214T1400Z-211215T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Diego County Coastal Areas-San Bernardino and Riverside County
Valleys-The Inland Empire-San Diego County Valleys-San Bernardino
County Mountains-Riverside County Mountains-Santa Ana Mountains and
Foothills-San Diego County Mountains-Apple and Lucerne Valleys-
Orange County Coastal Areas-Orange County Inland Areas-
Including the cities of Vista, Ontario, Santee, Idyllwild-Pine Cove, 
Fontana, Garden Grove, Fullerton, Lucerne Valley, Apple Valley, 
Hesperia, Santa Ana, National City, Riverside, Poway, Big Bear Lake, 
Oceanside, Big Bear City, San Diego, Lake Arrowhead, Irvine, El 
Cajon, Newport Beach, Escondido, Chula Vista, Crestline, San 
Clemente, Wrightwood, Corona, Anaheim, Huntington Beach, 
Victorville, San Bernardino, Moreno Valley, Mission Viejo, Laguna 
Beach, Julian, Pine Valley, Orange, Costa Mesa, La Mesa, Encinitas, 
Running Springs, San Marcos, Carlsbad, and Rancho Cucamonga
126 PM PST Mon Dec 13 2021

...FLOOD WATCH REMAINS IN EFFECT FROM TUESDAY MORNING THROUGH 
TUESDAY EVENING...

* WHAT...Flash flooding on Tuesday is possible due to excessive 
  rainfall through the day with isolated afternoon thunderstorms. 
  Rainfall rates of 0.50-0.60 inches per hour expected Tuesday. 
  Higher rainfall rates are expected on coastal mountain slopes, 
  particularly the San Bernardino Mountains, with rainfall rates of 
  0.75 inches an hour expected.

* WHERE...A portion of Southern California, including the following 
  areas, Apple and Lucerne Valleys, Orange County Coastal Areas, 
  Orange County Inland Areas, Riverside County Mountains, San 
  Bernardino County Mountains, San Bernardino and Riverside County 
  Valleys-The Inland Empire, San Diego County Coastal Areas, San 
  Diego County Mountains, San Diego County Valleys and Santa Ana 
  Mountains and Foothills. This Watch includes the Apple, El Dorado 
  and Bond burn scars.

* WHEN...From Tuesday morning through Tuesday evening.

* IMPACTS...Excessive runoff may result in flooding of rivers, 
  creeks, streams, and other low-lying and flood-prone locations. 
  Debris flows and flash flooding are possible near recent burn 
  scars, including the Apple, El Dorado and Bond burn scars.

* ADDITIONAL DETAILS...
  - A winter storm will bring significant precipitation to the
    area. Forecast rainfall amounts across the area include 1-1.5
    inches west of the mountains, 2-3 inches along the San Diego
    and Riverside county mountains below 5000 feet, 2-5+ inches
    below 5000 feet in the San Bernardino mountains, and 0.50-1
    inch in the High Desert.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood 
Warnings. Those living in areas prone to flooding should be prepared 
to take action should flooding develop.

&&

$$

CO
501 
WGUS66 KSGX 140500
FFASGX

Flood Watch
National Weather Service San Diego CA
900 PM PST Mon Dec 13 2021

CAZ043-048-050-055>058-060-552-554-141400-
/O.CON.KSGX.FA.A.0001.211214T1400Z-211215T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Diego County Coastal Areas-San Bernardino and Riverside County
Valleys-The Inland Empire-San Diego County Valleys-San Bernardino
County Mountains-Riverside County Mountains-Santa Ana Mountains and
Foothills-San Diego County Mountains-Apple and Lucerne Valleys-
Orange County Coastal Areas-Orange County Inland Areas-
Including the cities of Vista, Ontario, Santee, Idyllwild-Pine Cove, 
Fontana, Garden Grove, Fullerton, Lucerne Valley, Apple Valley, 
Hesperia, Santa Ana, National City, Riverside, Poway, Big Bear Lake, 
Oceanside, Big Bear City, San Diego, Lake Arrowhead, Irvine, El 
Cajon, Newport Beach, Escondido, Chula Vista, Crestline, San 
Clemente, Wrightwood, Corona, Anaheim, Huntington Beach, 
Victorville, San Bernardino, Moreno Valley, Mission Viejo, Laguna 
Beach, Julian, Pine Valley, Orange, Costa Mesa, La Mesa, Encinitas, 
Running Springs, San Marcos, Carlsbad, and Rancho Cucamonga
900 PM PST Mon Dec 13 2021

...FLOOD WATCH REMAINS IN EFFECT FROM 6 AM TUESDAY THROUGH TUESDAY 
EVENING...

* WHAT...Flash flooding on Tuesday is possible due to excessive 
  rainfall through the day with isolated afternoon thunderstorms. 
  Rainfall rates of 0.50-0.60 inches per hour expected Tuesday. 
  Higher rainfall rates are expected on coastal mountain slopes, 
  particularly the San Bernardino Mountains, with rainfall rates of 
  0.75 inches an hour expected.

* WHERE...A portion of Southern California, including the following 
  areas, Apple and Lucerne Valleys, Orange County Coastal Areas, 
  Orange County Inland Areas, Riverside County Mountains, San 
  Bernardino County Mountains, San Bernardino and Riverside County 
  Valleys-The Inland Empire, San Diego County Coastal Areas, San 
  Diego County Mountains, San Diego County Valleys and Santa Ana 
  Mountains and Foothills.

* WHEN...From 6 AM Tuesday through Tuesday evening.

* IMPACTS...Excessive runoff may result in flooding of rivers, 
  creeks, streams, and other low-lying and flood-prone locations. 
  Debris flows and flash flooding are possible near recent burn 
  scars, including the Apple, El Dorado and Bond burn scars.

* ADDITIONAL DETAILS...
  - A winter storm will bring significant precipitation to the
    area. Forecast rainfall amounts across the area include 1-1.5
    inches west of the mountains, 2-3 inches along the San Diego
    and Riverside county mountains below 5000 feet, 2-5+ inches
    below 5000 feet in the San Bernardino mountains, and 0.50-1
    inch in the High Desert.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood 
Warnings. Those living in areas prone to flooding should be prepared 
to take action should flooding develop.

&&

$$

Moede
163 
WGUS66 KSGX 141348
FFASGX

Flood Watch
National Weather Service San Diego CA
548 AM PST Tue Dec 14 2021

CAZ043-048-050-055>058-060-552-554-142200-
/O.CON.KSGX.FA.A.0001.211214T1400Z-211215T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Diego County Coastal Areas-San Bernardino and Riverside County
Valleys-The Inland Empire-San Diego County Valleys-San Bernardino
County Mountains-Riverside County Mountains-Santa Ana Mountains and
Foothills-San Diego County Mountains-Apple and Lucerne Valleys-
Orange County Coastal Areas-Orange County Inland Areas-
Including the cities of Vista, Ontario, Santee, Idyllwild-Pine Cove, 
Fontana, Garden Grove, Fullerton, Lucerne Valley, Apple Valley, 
Hesperia, Santa Ana, National City, Riverside, Poway, Big Bear Lake, 
Oceanside, Big Bear City, San Diego, Lake Arrowhead, Irvine, El 
Cajon, Newport Beach, Escondido, Chula Vista, Crestline, San 
Clemente, Wrightwood, Corona, Anaheim, Huntington Beach, 
Victorville, San Bernardino, Moreno Valley, Mission Viejo, Laguna 
Beach, Julian, Pine Valley, Orange, Costa Mesa, La Mesa, Encinitas, 
Running Springs, San Marcos, Carlsbad, and Rancho Cucamonga
548 AM PST Tue Dec 14 2021

...FLOOD WATCH REMAINS IN EFFECT THROUGH THIS EVENING...

* WHAT...Flooding caused by excessive rainfall continues to be 
  possible.

* WHERE...A portion of Southern California, including the following 
  areas, Apple and Lucerne Valleys, Orange County Coastal Areas, 
  Orange County Inland Areas, Riverside County Mountains, San 
  Bernardino County Mountains, San Bernardino and Riverside County 
  Valleys-The Inland Empire, San Diego County Coastal Areas, San 
  Diego County Mountains, San Diego County Valleys and Santa Ana 
  Mountains and Foothills.

* WHEN...Through this evening.

* IMPACTS...Excessive runoff may result in flooding of rivers, 
  creeks, streams, and other low-lying and flood-prone locations.

* ADDITIONAL DETAILS...
  - A winter storm will bring significant precipitation to the
    area. Forecast rainfall amounts across the area include 1-1.5
    inches west of the mountains, 2-3 inches along the San Diego
    and Riverside county mountains below 5000 feet, 2-6+ inches
    below 5000 feet in the San Bernardino mountains, and
    0.50-1.25 inch in the High Desert.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood 
Warnings. Those living in areas prone to flooding should be prepared 
to take action should flooding develop.

&&

$$

MM
626 
WGUS66 KSGX 142110
FFASGX

Flood Watch
National Weather Service San Diego CA
110 PM PST Tue Dec 14 2021

CAZ043-048-050-055>058-060-552-554-150500-
/O.CON.KSGX.FA.A.0001.000000T0000Z-211215T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Diego County Coastal Areas-San Bernardino and Riverside County
Valleys-The Inland Empire-San Diego County Valleys-San Bernardino
County Mountains-Riverside County Mountains-Santa Ana Mountains and
Foothills-San Diego County Mountains-Apple and Lucerne Valleys-
Orange County Coastal Areas-Orange County Inland Areas-
Including the cities of Vista, Ontario, Santee, Idyllwild-Pine Cove, 
Fontana, Garden Grove, Fullerton, Lucerne Valley, Apple Valley, 
Hesperia, Santa Ana, National City, Riverside, Poway, Big Bear Lake, 
Oceanside, Big Bear City, San Diego, Lake Arrowhead, Irvine, El 
Cajon, Newport Beach, Escondido, Chula Vista, Crestline, San 
Clemente, Wrightwood, Corona, Anaheim, Huntington Beach, 
Victorville, San Bernardino, Moreno Valley, Mission Viejo, Laguna 
Beach, Julian, Pine Valley, Orange, Costa Mesa, La Mesa, Encinitas, 
Running Springs, San Marcos, Carlsbad, and Rancho Cucamonga
110 PM PST Tue Dec 14 2021

...FLOOD WATCH REMAINS IN EFFECT UNTIL 9 PM PST THIS EVENING...

* WHAT...Flooding and localized flash flooding caused by excessive 
  rainfall and isolated thunderstorms continues to be possible 
  through this evening. Rainfall rates of 0.50 to 0.60 inches an 
  hour, locally up to 0.75 inches an hour at times expected through 
  late this afternoon.

* WHERE...A portion of Southern California, including the following 
  areas, Apple and Lucerne Valleys, Orange County Coastal Areas, 
  Orange County Inland Areas, Riverside County Mountains, San 
  Bernardino County Mountains, San Bernardino and Riverside County 
  Valleys-The Inland Empire, San Diego County Coastal Areas, San 
  Diego County Mountains, San Diego County Valleys and Santa Ana 
  Mountains and Foothills. This watch includes the Apple, El Dorado, 
  and Bond burn scars.

* WHEN...Until 9 PM PST this evening.

* IMPACTS...Excessive runoff may result in flooding of rivers, 
  creeks, streams, and other low-lying and flood-prone locations. 
  Debris flow and flash flooding are possible, especially near 
  recent burn scars, including Apple, El Dorado, and Bond burn scars.

* ADDITIONAL DETAILS...
  - A winter storm will bring significant precipitation to the
    area. Additional rainfall amounts of 0.50-1.5 inch west of
    the mountains, 2-3 inches along the San Diego and Riverside
    county mountains below 5000 feet, 2-4 inches below 5000 feet
    in the San Bernardino mountains, and 0.50 inch in the High
    Desert are possible.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood 
Warnings. Those living in areas prone to flooding should be prepared 
to take action should flooding develop.

&&

$$

CO

The office that day

Everything else NWS San Diego, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 12, 5:03 PM PSTGale WarningSGX59 hr
Dec 13, 3:50 AM PSTHigh Wind WarningSGXRiverside, San Bernardino, San Diego44 hr
Dec 13, 3:50 AM PSTWind AdvisorySGXOrange, Riverside, San Bernardino, San Diego44 hr
Dec 13, 3:53 AM PSTWinter Storm WarningSGXRiverside, San Bernardino44 hr
Dec 13, 1:07 PM PSTHigh Surf AdvisorySGXOrange, San Diego49 hr

Nearby

Flood Watches in California, 2021Every 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.