Alert archive / California / Flood Watches in 2021
Flood Watch 1, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flood watch at Dec 13, 2021, 12:00 PM PST for 11 counties in California. It took effect at Dec 13, 2021, 1:00 PM PST. It was in force for 12 hr.
The area
The counties it named.
The facts
- Issued
- Dec 13, 2021, 12:00 PM PST (20:00 UTC)
- In effect from
- Dec 13, 2021, 1:00 PM PST
- Expired
- Dec 14, 2021, 1:11 AM PST
- In force
- 12 hr
- Issued by
- NWS San Francisco Bay Area, CA
- Flood severity
- None
Counties Alameda County, CA, City and County of San Francisco, CA, Contra Costa County, CA, Marin County, CA, Monterey County, CA, Napa County, CA, San Benito County, CA, San Mateo County, CA, Santa Clara County, CA, Santa Cruz County, CA, Sonoma County, CA
The radar
The San Francisco radar (KMUX), 46 km from the middle of the area, began a volume at 20:04 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, 8.0 hours before the alert went out and 24 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.
- 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
The text
As transmitted.
388
WGUS66 KMTR 132000
FFAMTR
URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service San Francisco CA
1200 PM PST Mon Dec 13 2021
CAZ505>507-140300-
/O.NEW.KMTR.FA.A.0001.211213T2100Z-211214T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal North Bay Including Point Reyes National Seashore-North Bay
Interior Valleys-North Bay Mountains-
Including the cities of Woodacre, Sausalito, Santa Rosa,
Lagunitas-Forest Knolls, Angwin, Rohnert Park, San Rafael,
Tamalpais-Homestead, South Santa Rosa, Petaluma, Napa, and Novato
1200 PM PST Mon Dec 13 2021
...FLOOD WATCH IN EFFECT UNTIL 7 PM PST THIS EVENING...
* WHAT...Flooding caused by excessive rainfall is possible.
* WHERE...A portion of northern California, including the following
areas, Coastal North Bay Including Point Reyes National Seashore,
North Bay Interior Valleys and North Bay Mountains.
* WHEN...Until 7 PM PST this evening.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- High resolution models are showing a line of heavy rain
moving through the region with the potential of producing
periods of heavy rain this afternoon and through the early
evening hours.
- 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.
&&
$$
CAZ006-508>513-529-140400-
/O.NEW.KMTR.FA.A.0001.211214T0000Z-211214T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Francisco-San Francisco Bay Shoreline-San Francisco Peninsula
Coast-East Bay Interior Valleys-East Bay Hills and the Diablo Range-
Santa Cruz Mountains-Santa Clara Valley Including San Jose-Northern
Monterey Bay-
Including the cities of Livermore, Scotts Valley, Pacifica, San
Francisco, Hayward, Watsonville, Fremont, Live Oak, Santa Cruz, San
Ramon, Antioch, Berkeley, San Jose, Blackhawk, Walnut Creek, Daly
City, Boulder Creek, Concord, Day Valley, Pittsburg, Pleasanton, and
Oakland
1200 PM PST Mon Dec 13 2021
...FLOOD WATCH IN EFFECT FROM 4 PM THIS AFTERNOON TO 10 PM PST THIS
EVENING...
* WHAT...Flooding caused by excessive rainfall is possible.
* WHERE...A portion of northern California, including the following
areas, East Bay Hills and the Diablo Range, East Bay Interior
Valleys, Northern Monterey Bay, San Francisco, San Francisco Bay
Shoreline, San Francisco Peninsula Coast, Santa Clara Valley
Including San Jose and Santa Cruz Mountains.
* WHEN...From 4 PM this afternoon to 10 PM PST this evening.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- High resolution models are showing a line of heavy rain
moving through the region with the potential of producing
periods of heavy rain late this afternoon and through this
evening.
- 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.
&&
$$
CAZ517-530-140400-
/O.NEW.KMTR.FA.A.0001.211214T0300Z-211214T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
/O.CON.KMTR.FF.A.0004.000000T0000Z-211214T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Santa Lucia Mountains and Los Padres National Forest-Southern
Monterey Bay and Big Sur Coast-
Including the cities of Marina, Monterey, and Seaside
1200 PM PST Mon Dec 13 2021
...FLASH FLOOD WATCH FOR THE DOLAN BURN AREA REMAINS IN EFFECT
THROUGH LATE TONIGHT...
...FLOOD WATCH IN EFFECT FROM 7 PM PST THIS EVENING THROUGH LATE
TONIGHT...
* WHAT...Flash flooding and debris flows caused by excessive
rainfall continue to be possible over the Dolan burn area.
* WHERE...A portion of northern California, including the following
areas, Santa Lucia Mountains and Los Padres National Forest and
Southern Monterey Bay and Big Sur Coast.
* WHEN...Through late tonight.
* IMPACTS...Heavy rainfall over the Dolan burn area is expected up
to and during the period of the watch. Residents near the Dolan
burn area should prepare for potential flooding impacts. Be sure
to stay up to date with information from local authorities. Heavy
rainfall could trigger flash flooding of low-lying areas,
urbanized street flooding, and debris flows in and near recent
wildfire burn scars. Soils remain moist and excessive runoff may
result in flooding of rivers, creeks, streams, and other low-lying
and flood-prone locations.
* ADDITIONAL DETAILS...
- National Weather Service Meteorologists are forecasting heavy
rainfall over the Dolan burn area, which may lead to flash
flooding and debris flows.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.
Local emergency services are monitoring the situation and will issue
a public statement as conditions warrant. PLAN NOW so you will know
what to do in an emergency. Keep informed by listening to local
radio and television for statements and possible warnings. Follow
the advice of public safety officials.
&&
* WHAT...Flooding caused by excessive rainfall is possible.
* WHERE...A portion of northern California, including the following
areas, Santa Lucia Mountains and Los Padres National Forest and
Southern Monterey Bay and Big Sur Coast.
* WHEN...From 7 PM PST this evening through late tonight.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- High resolution models are showing a line of heavy rain
moving through the region with the potential of producing
periods of heavy rain this evening and through late tonight.
- 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.
&&
$$
CAZ516-518-528-140400-
/O.NEW.KMTR.FA.A.0001.211214T0300Z-211214T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Southern Salinas Valley/Arroyo Seco and Lake San Antonio-Mountains
Of San Benito County And Interior Monterey County Including
Pinnacles National Park-Northern Salinas Valley/Hollister Valley and
Carmel Valley-
Including the cities of Salinas, Greenfield, and King City
1200 PM PST Mon Dec 13 2021
...FLOOD WATCH IN EFFECT FROM 7 PM PST THIS EVENING THROUGH LATE
TONIGHT...
* WHAT...Flooding caused by excessive rainfall is possible.
* WHERE...A portion of northern California, including the following
areas, Mountains Of San Benito County And Interior Monterey County
Including Pinnacles National Park, Northern Salinas
Valley/Hollister Valley and Carmel Valley and Southern Salinas
Valley/Arroyo Seco and Lake San Antonio.
* WHEN...From 7 PM PST this evening through late tonight.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- High resolution models are showing a line of heavy rain
moving through the region with the potential of producing
periods of heavy rain this evening and through late tonight.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be alert for possible Flood
Warnings. Those living in areas prone to flooding should be prepared
to take action should flooding develop.
&&
$$
MTR4 follow-up statements
184
WGUS66 KMTR 132052
FFAMTR
URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service San Francisco CA
1252 PM PST Mon Dec 13 2021
CAZ509-512-529-140600-
/O.EXB.KMTR.FF.A.0004.211214T0000Z-211214T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
/O.CON.KMTR.FA.A.0001.211214T0000Z-211214T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Francisco Peninsula Coast-Santa Cruz Mountains-Northern Monterey
Bay-
Including the cities of Boulder Creek, Day Valley, Watsonville, Live
Oak, Scotts Valley, Santa Cruz, and Pacifica
1252 PM PST Mon Dec 13 2021
...FLASH FLOOD WATCH FOR THE CZU LIGHTNING COMPLEX BURN AREA IN
EFFECT FROM 4 PM THIS AFTERNOON TO 10 PM PST THIS EVENING...
...FLOOD WATCH REMAINS IN EFFECT FROM 4 PM THIS AFTERNOON TO 10 PM
PST THIS EVENING...
* WHAT...Flash flooding and debris flows caused by excessive
rainfall are possible over the CZU Lightning Complex burn area.
* WHERE...A portion of northern California, including the following
areas, Northern Monterey Bay, San Francisco Peninsula Coast and
Santa Cruz Mountains.
* WHEN...From 4 PM this afternoon to 10 PM PST this evening.
* IMPACTS...Heavy rainfall over the CZU Lightning Complex burn area
is expected up to and during the period of the watch. Residents
near the CZU Lightning Complex burn area should prepare for
potential flooding impacts. Be sure to stay up to date with
information from local authorities. Heavy rainfall could trigger
flash flooding of low-lying areas, urbanized street flooding, and
debris flows in and near recent wildfire burn scars. Soils remain
moist and excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Significant runoff may cause flooding of creeks and rivers. Storm
drains and ditches may become clogged with debris.
* ADDITIONAL DETAILS...
- National Weather Service Meteorologists are forecasting heavy
rainfall over the CZU Lightning Complex burn area, which may
lead to flash flooding and debris flows.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.
&&
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
areas, Northern Monterey Bay, San Francisco Peninsula Coast and
Santa Cruz Mountains.
* WHEN...From 4 PM this afternoon to 10 PM PST this evening.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- National Weather Service Meteorologists are forecasting heavy
rainfall over the CZU burn area, which may lead to flash
flooding and debris flows.
- 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.
&&
$$
CAZ528-141100-
/O.EXA.KMTR.FF.A.0004.000000T0000Z-211214T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
/O.CON.KMTR.FA.A.0001.211214T0300Z-211214T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Salinas Valley/Hollister Valley and Carmel Valley-
Including the cities of Salinas
1252 PM PST Mon Dec 13 2021
...FLASH FLOOD WATCH FOR THE CARMEL, RIVER, AND WILLOW BURN AREAS IN
EFFECT THROUGH LATE TONIGHT...
...FLOOD WATCH REMAINS IN EFFECT FROM 7 PM PST THIS EVENING THROUGH
LATE TONIGHT...
* WHAT...Flash flooding and debris flows caused by excessive
rainfall are possible over the Carmel, River and Willow burn areas.
* WHERE...A portion of northern California, including the following
area, Northern Salinas Valley/Hollister Valley and Carmel Valley.
* WHEN...Through late tonight.
* IMPACTS...Heavy rainfall over the Carmel, River and Willow burn
areas is expected up to and during the period of the watch.
Residents near the Carmel, River and Willow burn areas should
prepare for potential flooding impacts. Be sure to stay up to date
with information from local authorities. Heavy rainfall could
trigger flash flooding of low-lying areas, urbanized street
flooding, and debris flows in and near recent wildfire burn scars.
Soils remain moist and excessive runoff may result in flooding of
rivers, creeks, streams, and other low-lying and flood-prone
locations. Significant runoff may cause flooding of creeks and
rivers. Storm drains and ditches may become clogged with debris.
* ADDITIONAL DETAILS...
- National Weather Service Meteorologists are forecasting heavy
rainfall over the Carmel, River and Willow burn areas, which
may lead to flash flooding and debris flows.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.
Local emergency services are monitoring the situation and will issue
a public statement as conditions warrant. PLAN NOW so you will know
what to do in an emergency. Keep informed by listening to local
radio and television for statements and possible warnings. Follow
the advice of public safety officials.
&&
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
area, Northern Salinas Valley/Hollister Valley and Carmel Valley.
* WHEN...From 7 PM PST this evening through late tonight.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- National Weather Service Meteorologists are forecasting heavy
rainfall over the Carmel, River and Willow burn areas, which
may lead to flash flooding and debris flows.
- 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.
&&
$$
CAZ517-530-141100-
/O.CON.KMTR.FF.A.0004.000000T0000Z-211214T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
/O.CON.KMTR.FA.A.0001.211214T0300Z-211214T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Santa Lucia Mountains and Los Padres National Forest-Southern
Monterey Bay and Big Sur Coast-
Including the cities of Marina, Monterey, and Seaside
1252 PM PST Mon Dec 13 2021
...FLASH FLOOD WATCH FOR THE DOLAN BURN AREA REMAINS IN EFFECT
THROUGH LATE TONIGHT...
...FLOOD WATCH REMAINS IN EFFECT FROM 7 PM PST THIS EVENING THROUGH
LATE TONIGHT...
* WHAT...Flash flooding and debris flows caused by excessive
rainfall continue to be possible over the Dolan burn area.
* WHERE...A portion of northern California, including the following
areas, Santa Lucia Mountains and Los Padres National Forest and
Southern Monterey Bay and Big Sur Coast.
* WHEN...Through late tonight.
* IMPACTS...Heavy rainfall over the Dolan burn area is expected up
to and during the period of the watch. Residents near the Dolan
burn area should prepare for potential flooding impacts. Be sure
to stay up to date with information from local authorities. Heavy
rainfall could trigger flash flooding of low-lying areas,
urbanized street flooding, and debris flows in and near recent
wildfire burn scars. Soils remain moist and excessive runoff may
result in flooding of rivers, creeks, streams, and other low-lying
and flood-prone locations. Significant runoff may cause flooding
of creeks and rivers. Storm drains and ditches may become clogged
with debris.
* ADDITIONAL DETAILS...
- National Weather Service Meteorologists are forecasting heavy
rainfall over the Dolan burn area, which may lead to flash
flooding and debris flows.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.
Local emergency services are monitoring the situation and will issue
a public statement as conditions warrant. PLAN NOW so you will know
what to do in an emergency. Keep informed by listening to local
radio and television for statements and possible warnings. Follow
the advice of public safety officials.
&&
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
areas, Santa Lucia Mountains and Los Padres National Forest and
Southern Monterey Bay and Big Sur Coast.
* WHEN...From 7 PM PST this evening through late tonight.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- National Weather Service Meteorologists are forecasting heavy
rainfall over the Dolan burn area, which may lead to flash
flooding and debris flows.
- 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.
&&
$$
CAZ505>507-140300-
/O.CON.KMTR.FA.A.0001.211213T2100Z-211214T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal North Bay Including Point Reyes National Seashore-North Bay
Interior Valleys-North Bay Mountains-
Including the cities of Woodacre, Sausalito, Santa Rosa,
Lagunitas-Forest Knolls, Angwin, Rohnert Park, San Rafael,
Tamalpais-Homestead, South Santa Rosa, Petaluma, Napa, and Novato
1252 PM PST Mon Dec 13 2021
...FLOOD WATCH REMAINS IN EFFECT UNTIL 7 PM PST THIS EVENING...
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
areas, Coastal North Bay Including Point Reyes National Seashore,
North Bay Interior Valleys and North Bay Mountains.
* WHEN...Until 7 PM PST this evening.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- High resolution models are showing a line of heavy rain
moving through the region with the potential of producing
periods of heavy rain this afternoon and through the early
evening hours.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be alert for possible Flood
Warnings. Those living in areas prone to flooding should be prepared
to take action should flooding develop.
&&
$$
CAZ006-508-510-511-513-140600-
/O.CON.KMTR.FA.A.0001.211214T0000Z-211214T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Francisco-San Francisco Bay Shoreline-East Bay Interior Valleys-
East Bay Hills and the Diablo Range-Santa Clara Valley Including San
Jose-
Including the cities of Livermore, San Jose, Daly City, Concord,
Pittsburg, Fremont, Pleasanton, Blackhawk, San Ramon, Antioch,
Berkeley, San Francisco, Oakland, Walnut Creek, and Hayward
1252 PM PST Mon Dec 13 2021
...FLOOD WATCH REMAINS IN EFFECT FROM 4 PM THIS AFTERNOON TO 10 PM
PST THIS EVENING...
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
areas, East Bay Hills and the Diablo Range, East Bay Interior
Valleys, San Francisco, San Francisco Bay Shoreline and Santa
Clara Valley Including San Jose.
* WHEN...From 4 PM this afternoon to 10 PM PST this evening.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- High resolution models are showing a line of heavy rain
moving through the region with the potential of producing
periods of heavy rain late this afternoon and through this
evening.
- 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.
&&
$$
CAZ516-518-141100-
/O.CON.KMTR.FA.A.0001.211214T0300Z-211214T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Southern Salinas Valley/Arroyo Seco and Lake San Antonio-Mountains
Of San Benito County And Interior Monterey County Including
Pinnacles National Park-
Including the cities of Greenfield and King City
1252 PM PST Mon Dec 13 2021
...FLOOD WATCH REMAINS IN EFFECT FROM 7 PM PST THIS EVENING THROUGH
LATE TONIGHT...
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
areas, Mountains Of San Benito County And Interior Monterey County
Including Pinnacles National Park and Southern Salinas
Valley/Arroyo Seco and Lake San Antonio.
* WHEN...From 7 PM PST this evening through late tonight.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- High resolution models are showing a line of heavy rain
moving through the region with the potential of producing
periods of heavy rain this evening through late tonight.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be alert for possible Flood
Warnings. Those living in areas prone to flooding should be prepared
to take action should flooding develop.
&&
$$
MTR248
WGUS66 KMTR 140259
FFAMTR
Flood Watch
National Weather Service San Francisco CA
659 PM PST Mon Dec 13 2021
CAZ505>507-140400-
/O.EXP.KMTR.FA.A.0001.000000T0000Z-211214T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coastal North Bay Including Point Reyes National Seashore-North Bay
Interior Valleys-North Bay Mountains-
Including the cities of Woodacre, Sausalito, Santa Rosa,
Lagunitas-Forest Knolls, Angwin, Rohnert Park, San Rafael,
Tamalpais-Homestead, South Santa Rosa, Petaluma, Napa, and Novato
659 PM PST Mon Dec 13 2021
...FLOOD WATCH WILL EXPIRE AT 7 PM PST THIS EVENING...
The Flood Watch will expire for a portion of northern California,
including the following areas, Coastal North Bay Including Point
Reyes National Seashore, North Bay Interior Valleys and North Bay
Mountains.
The flooding threat has ended. Therefore, the Flood Watch will
expire at 7 PM PST this evening.
$$
CAZ517-528-530-141100-
/O.CON.KMTR.FF.A.0004.000000T0000Z-211214T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
/O.CON.KMTR.FA.A.0001.211214T0300Z-211214T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Santa Lucia Mountains and Los Padres National Forest-Northern
Salinas Valley/Hollister Valley and Carmel Valley-Southern Monterey
Bay and Big Sur Coast-
Including the cities of Marina, Monterey, Salinas, and Seaside
659 PM PST Mon Dec 13 2021
...FLASH FLOOD WATCH FOR THE DOLAN BURN AREA REMAINS IN EFFECT UNTIL
1 AM PST TUESDAY...
...FLOOD WATCH REMAINS IN EFFECT UNTIL 3 AM PST TUESDAY...
* WHAT...Flash flooding and debris flows caused by excessive
rainfall continue to be possible over the Dolan burn area.
* WHERE...A portion of northern California, including the following
areas, Northern Salinas Valley/Hollister Valley and Carmel Valley,
Santa Lucia Mountains and Los Padres National Forest and Southern
Monterey Bay and Big Sur Coast.
* WHEN...Until 1 AM PST Tuesday.
* IMPACTS...Heavy rainfall over the Dolan burn area is expected up
to and during the period of the watch. Residents near the Dolan
burn area should prepare for potential flooding impacts. Be sure
to stay up to date with information from local authorities. Heavy
rainfall could trigger flash flooding of low-lying areas,
urbanized street flooding, and debris flows in and near recent
wildfire burn scars. Soils remain moist and excessive runoff may
result in flooding of rivers, creeks, streams, and other low-lying
and flood-prone locations. Significant runoff may cause flooding
of creeks and rivers. Storm drains and ditches may become clogged
with debris.
* ADDITIONAL DETAILS...
- National Weather Service Meteorologists are forecasting heavy
rainfall over the Dolan burn area, which may lead to flash
flooding and debris flows.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.
Local emergency services are monitoring the situation and will issue
a public statement as conditions warrant. PLAN NOW so you will know
what to do in an emergency. Keep informed by listening to local
radio and television for statements and possible warnings. Follow
the advice of public safety officials.
&&
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
areas, Northern Salinas Valley/Hollister Valley and Carmel Valley,
Santa Lucia Mountains and Los Padres National Forest and Southern
Monterey Bay and Big Sur Coast.
* WHEN...Until 3 AM PST Tuesday.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- Periods of moderate to heavy rain will be possible through
late tonight.
- 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.
&&
$$
CAZ509-512-529-140600-
/O.CON.KMTR.FA.A.0001.000000T0000Z-211214T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
/O.CON.KMTR.FF.A.0004.000000T0000Z-211214T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Francisco Peninsula Coast-Santa Cruz Mountains-Northern Monterey
Bay-
Including the cities of Boulder Creek, Day Valley, Watsonville, Live
Oak, Scotts Valley, Santa Cruz, and Pacifica
659 PM PST Mon Dec 13 2021
...FLOOD WATCH REMAINS IN EFFECT UNTIL 10 PM PST THIS EVENING...
...FLASH FLOOD WATCH FOR THE CZU LIGHTNING COMPLEX BURN AREA REMAINS
IN EFFECT UNTIL 10 PM PST THIS EVENING...
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
areas, Northern Monterey Bay, San Francisco Peninsula Coast and
Santa Cruz Mountains.
* WHEN...Until 10 PM PST this evening.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- Periods of moderate to heavy rain will be possible through
this evening.
- 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.
&&
* WHAT...Flash flooding and debris flows caused by excessive
rainfall continue to be possible over the CZU Lightning Complex
burn area.
* WHERE...A portion of northern California, including the following
areas, Northern Monterey Bay, San Francisco Peninsula Coast and
Santa Cruz Mountains.
* WHEN...Until 10 PM PST this evening.
* IMPACTS...Heavy rainfall over the CZU Lightning Complex burn area
is expected up to and during the period of the watch. Residents
near the CZU Lightning Complex burn area should prepare for
potential flooding impacts. Be sure to stay up to date with
information from local authorities. Heavy rainfall could trigger
flash flooding of low-lying areas, urbanized street flooding, and
debris flows in and near recent wildfire burn scars. Soils remain
moist and excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Significant runoff may cause flooding of creeks and rivers. Storm
drains and ditches may become clogged with debris.
* ADDITIONAL DETAILS...
- National Weather Service Meteorologists are forecasting heavy
rainfall over the CZU Lightning Complex burn area, which may
lead to flash flooding and debris flows.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.
&&
$$
CAZ006-508-510-511-513-140600-
/O.CON.KMTR.FA.A.0001.000000T0000Z-211214T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Francisco-San Francisco Bay Shoreline-East Bay Interior Valleys-
East Bay Hills and the Diablo Range-Santa Clara Valley Including San
Jose-
Including the cities of Livermore, San Jose, Daly City, Concord,
Pittsburg, Fremont, Pleasanton, Blackhawk, San Ramon, Antioch,
Berkeley, San Francisco, Oakland, Walnut Creek, and Hayward
659 PM PST Mon Dec 13 2021
...FLOOD WATCH REMAINS IN EFFECT UNTIL 10 PM PST THIS EVENING...
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
areas, East Bay Hills and the Diablo Range, East Bay Interior
Valleys, San Francisco, San Francisco Bay Shoreline and Santa
Clara Valley Including San Jose.
* WHEN...Until 10 PM PST this evening.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- Periods of moderate to heavy rain will be possible through
this evening.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be alert for possible Flood
Warnings. Those living in areas prone to flooding should be prepared
to take action should flooding develop.
&&
$$
CAZ516-518-141100-
/O.CON.KMTR.FA.A.0001.211214T0300Z-211214T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Southern Salinas Valley/Arroyo Seco and Lake San Antonio-Mountains
Of San Benito County And Interior Monterey County Including
Pinnacles National Park-
Including the cities of Greenfield and King City
659 PM PST Mon Dec 13 2021
...FLOOD WATCH REMAINS IN EFFECT UNTIL 3 AM PST TUESDAY...
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
areas, Mountains Of San Benito County And Interior Monterey County
Including Pinnacles National Park and Southern Salinas
Valley/Arroyo Seco and Lake San Antonio.
* WHEN...Until 3 AM PST Tuesday.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- Periods of moderate to heavy rain will be possible through
late tonight.
- 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.
&&
$$
MTR735
WGUS66 KMTR 140559
FFAMTR
Flood Watch
National Weather Service San Francisco CA
959 PM PST Mon Dec 13 2021
CAZ509-512-529-140700-
/O.EXP.KMTR.FA.A.0001.000000T0000Z-211214T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
/O.EXP.KMTR.FF.A.0004.000000T0000Z-211214T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Francisco Peninsula Coast-Santa Cruz Mountains-Northern Monterey
Bay-
Including the cities of Boulder Creek, Day Valley, Watsonville, Live
Oak, Scotts Valley, Santa Cruz, and Pacifica
959 PM PST Mon Dec 13 2021
...FLOOD WATCH WILL EXPIRE AT 10 PM PST THIS EVENING...
...FLASH FLOOD WATCH FOR THE CZU LIGHTNING COMPLEX BURN AREA WILL
EXPIRE AT 10 PM PST THIS EVENING...
The Flood Watch will expire for the following areas, Northern
Monterey Bay, San Francisco Peninsula Coast and Santa Cruz Mountains.
The flooding threat continues to diminish. Therefore, the Flood
Watch will expire at 10 PM PST this evening.
The Flash Flood Watch will expire following areas, Northern Monterey
Bay, San Francisco Peninsula Coast and Santa Cruz Mountains.
The flooding threat continues to diminish Therefore, the Flash Flood
Watch will expire at 10 PM PST this evening.
$$
CAZ006-508-510-511-513-140700-
/O.EXP.KMTR.FA.A.0001.000000T0000Z-211214T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Francisco-San Francisco Bay Shoreline-East Bay Interior Valleys-
East Bay Hills and the Diablo Range-Santa Clara Valley Including San
Jose-
Including the cities of Livermore, San Jose, Daly City, Concord,
Pittsburg, Fremont, Pleasanton, Blackhawk, San Ramon, Antioch,
Berkeley, San Francisco, Oakland, Walnut Creek, and Hayward
959 PM PST Mon Dec 13 2021
...FLOOD WATCH WILL EXPIRE AT 10 PM PST THIS EVENING...
The Flood Watch will expire for the following areas, East Bay Hills
and the Diablo Range, East Bay Interior Valleys, San Francisco, San
Francisco Bay Shoreline and Santa Clara Valley Including San Jose.
The flooding threat continues to diminish. Therefore, the Flood
Watch will expire at 10 PM PST this evening.
$$
CAZ517-528-530-141100-
/O.CON.KMTR.FA.A.0001.000000T0000Z-211214T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
/O.CON.KMTR.FF.A.0004.000000T0000Z-211214T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Santa Lucia Mountains and Los Padres National Forest-Northern
Salinas Valley/Hollister Valley and Carmel Valley-Southern Monterey
Bay and Big Sur Coast-
Including the cities of Marina, Monterey, Salinas, and Seaside
959 PM PST Mon Dec 13 2021
...FLOOD WATCH REMAINS IN EFFECT UNTIL 3 AM PST TUESDAY...
...FLASH FLOOD WATCH FOR THE DOLAN BURN AREA REMAINS IN EFFECT UNTIL
1 AM PST TUESDAY...
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
areas, Northern Salinas Valley/Hollister Valley and Carmel Valley,
Santa Lucia Mountains and Los Padres National Forest and Southern
Monterey Bay and Big Sur Coast.
* WHEN...Until 3 AM PST Tuesday.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- Periods of moderate to heavy rain will be possible through
late tonight.
- 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.
&&
* WHAT...Flash flooding and debris flows caused by excessive
rainfall are possible over the Carmel, River and Willow burn areas.
* WHERE...A portion of northern California, including the following
areas, Northern Salinas Valley/Hollister Valley and Carmel Valley,
Santa Lucia Mountains and Los Padres National Forest and Southern
Monterey Bay and Big Sur Coast.
* WHEN...Until 1 AM PST Tuesday.
* IMPACTS...Heavy rainfall over the Carmel, River and Willow burn
areas is expected up to and during the period of the watch.
Residents near the Carmel, River and Willow burn areas should
prepare for potential flooding impacts. Be sure to stay up to date
with information from local authorities. Heavy rainfall could
trigger flash flooding of low-lying areas, urbanized street
flooding, and debris flows in and near recent wildfire burn scars.
Soils remain moist and excessive runoff may result in flooding of
rivers, creeks, streams, and other low-lying and flood-prone
locations. Significant runoff may cause flooding of creeks and
rivers. Storm drains and ditches may become clogged with debris.
* ADDITIONAL DETAILS...
- National Weather Service Meteorologists are forecasting heavy
rainfall over the Carmel, River and Willow burn areas, which
may lead to flash flooding and debris flows.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.
Local emergency services are monitoring the situation and will issue
a public statement as conditions warrant. PLAN NOW so you will know
what to do in an emergency. Keep informed by listening to local
radio and television for statements and possible warnings. Follow
the advice of public safety officials.
&&
$$
CAZ516-518-141100-
/O.CON.KMTR.FA.A.0001.000000T0000Z-211214T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Southern Salinas Valley/Arroyo Seco and Lake San Antonio-Mountains
Of San Benito County And Interior Monterey County Including
Pinnacles National Park-
Including the cities of Greenfield and King City
959 PM PST Mon Dec 13 2021
...FLOOD WATCH REMAINS IN EFFECT UNTIL 3 AM PST TUESDAY...
* WHAT...Flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of northern California, including the following
areas, Mountains Of San Benito County And Interior Monterey County
Including Pinnacles National Park and Southern Salinas
Valley/Arroyo Seco and Lake San Antonio.
* WHEN...Until 3 AM PST Tuesday.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Creeks and streams may rise out of their banks. Flooding may occur
in poor drainage and urban areas. Low-water crossings may be
flooded. Storm drains and ditches may become clogged with debris.
Extensive street flooding and flooding of creeks and rivers are
possible.
* ADDITIONAL DETAILS...
- Periods of moderate to heavy rain will be possible through
late tonight.
- 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.
&&
$$
Gass253 WGUS66 KMTR 140911 FFAMTR Flood Watch National Weather Service San Francisco CA 111 AM PST Tue Dec 14 2021 CAZ517-528-530-141015- /O.CAN.KMTR.FA.A.0001.000000T0000Z-211214T1100Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ /O.EXP.KMTR.FF.A.0004.000000T0000Z-211214T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Santa Lucia Mountains and Los Padres National Forest-Northern Salinas Valley/Hollister Valley and Carmel Valley-Southern Monterey Bay and Big Sur Coast- Including the cities of Marina, Monterey, Salinas, and Seaside 111 AM PST Tue Dec 14 2021 ...FLASH FLOOD WATCH FOR THE DOLAN BURN AREA HAS EXPIRED... ...FLOOD WATCH IS CANCELLED... The Flash Flood Watch has expired for a portion of northern California, including the following areas, Northern Salinas Valley/Hollister Valley and Carmel Valley, Santa Lucia Mountains and Los Padres National Forest and Southern Monterey Bay and Big Sur Coast. The Flood Watch is cancelled for a portion of northern California, including the following areas, Northern Salinas Valley/Hollister Valley and Carmel Valley, Santa Lucia Mountains and Los Padres National Forest and Southern Monterey Bay and Big Sur Coast. The threat for flooding continues to diminish and is no longer expected to pose a threat. Please continue to heed remaining road closures. $$ CAZ516-518-141015- /O.CAN.KMTR.FA.A.0001.000000T0000Z-211214T1100Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Southern Salinas Valley/Arroyo Seco and Lake San Antonio-Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park- Including the cities of Greenfield and King City 111 AM PST Tue Dec 14 2021 ...FLOOD WATCH IS CANCELLED... The Flood Watch is cancelled for a portion of northern California, including the following areas, Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park and Southern Salinas Valley/Arroyo Seco and Lake San Antonio. The threat for flooding continues to diminish and is no longer expected to pose a threat. Please continue to heed remaining road closures. $$ Gass
What forecasters said that day
The local office's own words before this flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS San Francisco Bay Area, CA wrote its last area forecast discussion before this flood watch went out at Dec 13, 12:00 PM PST, 0 minutes earlier.
Area forecast discussion, Dec 13, 12:00 PM PST, 0 minutes before
Area Forecast Discussion
National Weather Service San Francisco Bay Area
1200 PM PST Mon Dec 13 2021
.SYNOPSIS...
A potent weather system will impact the region today bringing
strong winds, locally heavy rain, and hazardous marine
conditions. Another weaker system arrives for mid week bringing
light precipitation and much colder temperatures by Friday night.
&&
.DISCUSSION...as of 11:57 AM PST Monday...Late morning update..A
relatively quiet early morning has become much more active over
the last 2 hours as rainfall intensity has increased over the SF
Bay and areas to the south. KMUX radar showed an intense rain band
cross over the CZU burn scar triggering the issuance of a Flash
Flood Warning in the last hour. An hourly rain gauge report at Ben
Lomond indicated .75"/hr precip rate, which exceeds the burn scar
threshold of .70"/hr. No signs of rain activity letting up on
radar, though are seeing a gradual shift away from the Bay Area
towards the Central Coast, which will receive the brunt of the
storm impacts today and tonight. Areal Flood Advisories are also
in effect elsewhere in Santa Cruz County, San Mateo County and
around the SF Bay Shoreline as numerous reports of flooded
roadways have been coming in. Also seeing some reports of small
mudslides/debris flows in Santa Cruz County. A Flash Flood Watch
is still in effect for the Dolan Burn Scar in Monterey County,
along with a High Wind Warning for Monterey/San Benito Counties
through 9 p.m. and a Wind Advisory for the SF Bay Area (excluding
North Bay) through 4 p.m. A cold unstable airmass will filter into
the area from the north later today, setting off convection and
some stronger winds. More flood watch products likely to be issued
covering Santa Cruz and Monterey Counties today. Stay tuned.
&&
.PREV DISCUSSION...as of 3:15 AM PST Monday...
Today through Tuesday:
An expansive mid to upper trough enveloped the northeast Pacific and
Gulf of Alaska this morning with a cold core low centered near
50N/140W. A belt of 45 kt low to mid level southwesterly flow was
located along the leading edge of the trough with a focused moisture
plume angled into the Central California Coast in the form of an
Atmospheric River. A surface cold front was analyzed just south of
the Golden gate. Light to occasionally moderate rain showers were
occurring mostly north of a Watsonville to Gilroy line with rain
rates on the order of 0.1 to 0.3 inches per hour. Heavier showers
were approaching the Big Sur and Monterey Bay coast areas as of
this writing.
Given the progressive flow pattern aloft the cold and unstable
airmass associated with the upper low should filter into the area
later today into Tuesday. This should reinvigorate the storm system
while giving extra "oomph" to the frontal zone in the form of
increased frontogenesis (or forcing for ascent -- which aids in
precipitation development). So not only will the large-scale
dynamics improve with increased differential cyclonic vorticity
advection and jet-level divergence (sources for large-scale lift),
but the low to mid level flow should increase to around 60 kt
later this morning into this afternoon. This keeps a focused
moisture feed (precipitable water anomalies ~2 to 2.5 standard
deviations) into the Central Coast through the remainder of the
day with increasing rain rates anticipated. Of particular concern
is for localized rates in the Santa Lucia range to approach or
possibly exceed 1 inch per hour, which would be problematic for
hydrologically sensitive areas such as the Dolan wildfire burn
scar. For this reason a Flash Flood Watch was issued for this area
yesterday.
In addition to hydrologic concerns (more on that below) this will be
a multi-pronged event with strong winds, hazardous marine and beach
conditions, and the potential for a few thunderstorms. Please see
below for more details on timing, additional rain amounts, and other
impacts expected from this system.
* Rain Timing: As the cold front intensifies today the focus for
moderate to locally heavy rainfall should shift south of the
Golden Gate. This should initially include the Santa Cruz
mountains this morning with a gradual shift towards the Santa
Lucias during the afternoon and evening. This isn't to say that
showers aren't possible elsewhere, but that it appears the
steadiest/highest rain rates should be concentrated along the Big
Sur coast through the afternoon and evening hours. As mentioned
rain rates in this area could approach or exceed 1 inch per hour
with the potential for debris flows in sensitive areas. This
period of higher rain rates may persist into this evening before
decreasing Tuesday morning. Scattered showers and isolated
thunderstorms remain possible into Tuesday before diminishing
during the late morning to early afternoon.
* Rain Amounts: Additional amounts of 1 inch or less are expected
for the North Bay Valleys (higher in the coastal ranges), with
around 1 to 1.25 inches for San Francisco proper and the
South/East Bays. The greatest additional amounts today should be
south of the Golden Gate. This includes 2 to 5 inches for the
Santa Cruz Mountains, 1.5 to 3 inches for Monterey Bay and the
Salinas Valley, and 5 to 8 inches for the Santa Lucia Range.
Isolated amounts of 10-12 inches are possible for the higher peaks
along the Big Sur Coast.
* Potential Hydrologic Impacts: While dry antecedent conditions have
lessened the potential for widespread impacts, notable local
issues remain possible. Among them: 1) minor nuisance flooding of
urban and/or poorly draining areas; 2) localized rockslides in
canyons and steep hillsides; and 3) flash flooding and debris
flows for hydrologically vulnerable areas such as wildfire burn
scars. This concern is greatest for the Dolan burn scar, where a
Flash Flood Watch is in effect. However we will also monitor the
CZU and River burn scars for potential issues today. While
mainstem river flooding isn't currently anticipated, heavy rain
will lead to rapid rises on area rivers, streams, and creeks.
Outside of water related concerns here's a bit more on other local
impacts we're anticipating from this system.
* Wind: strong southerly winds will develop today ahead of an
advancing cold front. Look for sustained speeds in the 20 to 30
mph range for many areas with gusts locally exceeding 60 mph. A
Wind Advisory is in effect for San Francisco and the South/East
Bays into this evening. A High Wind Warning is in effect for
Monterey and San Benito Counties through early tonight. These
winds will create difficult travel for high profile vehicles and
will result in downed trees and power lines.
* Thunderstorms: sufficient instability exists this afternoon into
early Tuesday for a few thunderstorms to develop. This potential
appears greatest for the local waters and North Bay, but chances
could extend south along the coast as well. Lightning, gusty
winds, and small hail would be the primary hazards.
* Mountain Snow: as cooler air filters into the region snow levels
should drop to ~2500-3000 ft late tonight into Tuesday. This
suggests precipitation may end as snow at some of the higher peaks
where light accumulations are possible.
* Marine and Beach Conditions: hazardous conditions are expected
with very steep wind driven seas and gale-force winds developing
across portions of the local waters. High surf is also anticipated
with large breaking waves capable for sweeping people off jetties
and docks and into the ocean.
Wednesday and Beyond:
An active pattern continues with another storm system impacting the
area on Wednesday into Thursday. This system, while weaker than the
previous one, may bring an inch or so of precipitation to parts of
the area. Rain and low elevation snow are possible given the colder
air with this system. Cold temperatures should prevail for late week
with frost and freezing temperatures possible for many areas. More
details to come with future updates.
&&
.AVIATION...as of 10:10 AM PST Monday...For the 18z TAFs.
Extremely dynamic set up today with two cold frontal boundaries
and a robust cold core set to overtake the region today. Periods
of -RA to +RA expected through the day at most terminals as the
secondary enhanced cold front overtakes the weaker surface front.
Gusty southerly winds of up to 25-35kt at terminals is possible
through the day as the secondary boundary nears, with a shift
towards the west later this afternoon to evening and a decrease in
wind speed and an end in the gusts in the wake of the second
front. Then, scattered to widespread showers and isolated
thunderstorms are expected to arrive in the wake of the cold front
later today through the night. These showers and thunderstorms will
be capable of brief heavy downpours, poor visibility, gusty
erratic winds, lightning, and copious amount of small hail. Will
aim to AMD TAF to include the potential for these thunderstorms
at TAF site vicinity as they begin to develop and move. VFR
conditions return temporarily tomorrow morning to early afternoon
before another storm system rolls in between Wednesday into
Thursday.
Vicinity of KSFO...Mostly MVFR conditions with occasional IFR as
stronger FROPA moves through the area today. Southerly to
southwesterly winds will become gusty beginning around 18Z and
lasting through 00Z. Gusts will reach up to 35kts with occasional
gusts up to 40kts. As front passes there could be brief periods of
LIFR visibilities due to +RA. Winds should diminish to AOB 15kts
by 03Z tonight for all Bay Area terminals. -RA should stop around
12Z Tuesday with skies starting to scatter out after 15Z. Potential
for passing showers and thunderstorms later today may bring
additional concerns.
KSFO Bridge Approach...Similar to KSFO.
Monterey Bay...VFR ceilings will fall to MVFR later this morning
as RA to +RA will persist for most of the period. Gusty southerly
winds ahead of FROPA this afternoon and evening with winds
diminishing around 06Z. There will be chances for +RA and LIFR
visibilities as the front moves through this afternoon. Trailing
showers through the evening and overnight period. Improving
conditions through tomorrow morning.
&&
.MARINE...as of 11:57 AM PST Monday...Gusty southerly winds across
the waters will continue through tomorrow. Expect strong and
gusty winds especially across the Monterey Bay and Big Sur coast
today lasting through tonight. Southerly winds will also
strengthen across the San Francisco Bay Monday afternoon and
early evening. Very steep southerly wind waves are expected to
continue today creating hazardous conditions for vessels. A large
longer period WNW swell train has arrived in the waters today and
will peak through Tuesday and bring hazardous conditions through
harbor entrances and the surf zone. The Coast Guard advises all
mariners to ensure their boats are tethered to port prior to the
arrival of this potent storm system.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tday...High Wind Warning...*CAZ516>518-528-530*
Flash Flood Watch...*CAZ517*
Wind Advisory...*CAZ006-508>513-529*
High Surf Advisory...*CAZ006-505-509-529-530*
GLW...Mry Bay
GLW...Pigeon Pt to Pt Pinos 0-10 nm
GLW...Pt Pinos to Pt Piedras Blancas 0-10 nm
SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...Pt Reyes to Pigeon Pt 0-10 nm
SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
SCA...SF Bay
&&
PUBLIC FORECAST: Lorber/SPM
AVIATION: DRP
MARINE: DRP
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Local storm report, Dec 13, 11:38 AM PST, 22 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1138 AM PST MON DEC 13 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1023 AM NON-TSTM WND DMG 4 WNW FELTON 37.06N 122.14W
12/13/2021 SANTA CRUZ CA LAW ENFORCEMENT
POWER LINES DOWN AT ICE CREAM GRADE ROAD AND
WINTER CREEK ROAD. ROADWAY COMPLETELY
BLOCKED.
&&
ACLocal storm report, Dec 13, 11:42 AM PST, 18 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1142 AM PST MON DEC 13 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1043 AM FLOOD 1 SW BOULDER CREEK 37.13N 122.14W
12/13/2021 SANTA CRUZ CA LAW ENFORCEMENT
ROADWAY FLOODING AT 14320 SR236 NEAR BIG
BASIN WAY.
&&
ACLocal storm report, Dec 13, 11:44 AM PST, 16 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1144 AM PST MON DEC 13 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1041 AM FLOOD 9 W FELTON 37.04N 122.23W
12/13/2021 SANTA CRUZ CA LAW ENFORCEMENT
ROADWAY FLOODING ACROSS BRIDGE AT SR 1 N
DIRECTION NEAR SCOTT CREEK.
&&
ACLocal storm report, Dec 13, 11:52 AM PST, 8 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1152 AM PST MON DEC 13 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1054 AM FLOOD 1 W BOULDER CREEK 37.14N 122.14W
12/13/2021 SANTA CRUZ CA LAW ENFORCEMENT
MUD/DIRT/ROCKS FLOWING ONTO ROADWAY NEAR 295
RIDGE DRIVE.
&&
ACLocal storm report, Dec 13, 11:57 AM PST, 3 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1157 AM PST MON DEC 13 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1155 AM FLOOD 4 ENE SCOTTS VALLEY 37.08N 121.95W
12/13/2021 SANTA CRUZ CA LAW ENFORCEMENT
POWER LINES DOWN ACROSS ROAD AT SOQUEL SAN
JOSE RD AND HESTER CREEK RD. TREES ALSO DOWN
IN AREA.
&&
ACLocal storm report, Dec 13, 11:59 AM PST, 1 minute before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1159 AM PST MON DEC 13 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1109 AM NON-TSTM WND DMG 4 WNW FELTON 37.06N 122.15W
12/13/2021 SANTA CRUZ CA LAW ENFORCEMENT
TREES ON POWER LINES OVER ROADWAY AT BONNY
DOON RD AND PINE FLAT RD.
&&
ACThe 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 | MTR | San Mateo, Santa Cruz | 60 min |
| Dec 13, 1:26 PM PST | Areal Flood Advisory | MTR | San Mateo | 11 hr |
| Dec 13, 1:45 PM PST | Flash Flood Warning | MTR | Monterey | 6 hr |
| Dec 13, 2:42 PM PST | Areal Flood Warning | MTR | Santa Cruz | 4 hr |
Nearby
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.