Alert archive / California / Flash Flood Watches in 2017

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

January 20, 201711 counties in California

NWS San Francisco Bay Area, CA issued this flash flood watch at Jan 20, 2017, 1:27 PM PST for 11 counties in California. It took effect at Jan 22, 2017, 12:00 AM PST. It was in force for 38 hr.

The area

The counties it named.

The facts

Issued
Jan 20, 2017, 1:27 PM PST (21:27 UTC)
In effect from
Jan 22, 2017, 12:00 AM PST
Expired
Jan 23, 2017, 2:17 PM PST
In force
38 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 21:29 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Oakland, CA (KOAK), launched 12:00Z, 9.5 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.

Skew-T log-pSkew-T log-p diagram, Oakland, CA at 12:00Z on 2017-01-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Oakland, CA at 12:00Z on 2017-01-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 501 square meters per square second.1939587897117Sfc1 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
774 m above ground
0-6 km bulk shear
73 kt
0-1 km storm-relative helicity
501 m²/s²
0-3 km storm-relative helicity
746 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

491 
WGUS66 KMTR 202127
FFAMTR

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
127 PM PST FRI JAN 20 2017

...FLASH FLOOD WATCH FOR THE ENTIRE SAN FRANCISCO BAY AREA AND
CENTRAL COAST...

.THE THIRD IN A SERIES OF STRONG STORMS IS EXPECTED TO PRODUCE
PERIODS OF MODERATE TO HEAVY RAIN SATURDAY NIGHT THROUGH SUNDAY
MORNING. THIS ADDITIONAL RAIN ON ALREADY SATURATED SOILS WILL
LIKELY LEAD TO FLASH FLOODING OF AREA STREAMS AND RIVERS AS WELL
AS IN LOCAL URBAN AREAS. 

CAZ006-505>513-516>518-528>530-211200-
/O.NEW.KMTR.FF.A.0004.170122T0800Z-170123T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN FRANCISCO-
COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE-
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
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-
SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN ANTONIO-
SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST-
MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY
INCLUDING PINNACLES NATIONAL MONUMENT-
NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL VALLEY-
NORTHERN MONTEREY BAY-SOUTHERN MONTEREY BAY AND BIG SUR COAST-
INCLUDING THE CITIES OF...SAN FRANCISCO...TAMALPAIS-HOMESTEAD...
SAUSALITO...SANTA ROSA...SOUTH SANTA ROSA...NAPA...SAN RAFAEL...
PETALUMA...NOVATO...ROHNERT PARK...ANGWIN...
LAGUNITAS-FOREST KNOLLS...WOODACRE...OAKLAND...FREMONT...
HAYWARD...DALY CITY...BERKELEY...PACIFICA...CONCORD...ANTIOCH...
LIVERMORE...WALNUT CREEK...PLEASANTON...PITTSBURG...SAN RAMON...
BLACKHAWK...SCOTTS VALLEY...BOULDER CREEK...DAY VALLEY...
SAN JOSE...GREENFIELD...KING CITY...SALINAS...SANTA CRUZ...
WATSONVILLE...LIVE OAK...SEASIDE...MONTEREY...MARINA
127 PM PST FRI JAN 20 2017

...FLASH FLOOD WATCH IN EFFECT FROM LATE SATURDAY NIGHT THROUGH
SUNDAY 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...EAST BAY HILLS AND THE DIABLO 
  RANGE...EAST BAY INTERIOR VALLEYS...MOUNTAINS OF SAN BENITO 
  COUNTY AND INTERIOR MONTEREY COUNTY INCLUDING PINNACLES 
  NATIONAL MONUMENT...NORTH BAY INTERIOR VALLEYS...NORTH BAY 
  MOUNTAINS...NORTHERN MONTEREY BAY...NORTHERN SALINAS 
  VALLEY/HOLLISTER VALLEY AND CARMEL VALLEY...SAN FRANCISCO... 
  SAN FRANCISCO BAY SHORELINE...SAN FRANCISCO PENINSULA COAST... 
  SANTA CLARA VALLEY INCLUDING SAN JOSE...SANTA CRUZ MOUNTAINS...
   SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST... 
  SOUTHERN MONTEREY BAY AND BIG SUR COAST AND SOUTHERN SALINAS 
  VALLEY/ARROYO SECO AND LAKE SAN ANTONIO. 

* FROM LATE SATURDAY NIGHT THROUGH SUNDAY AFTERNOON

* PERIODS OF HEAVY RAIN ON SATURATED SOILS WILL IMPACT THE REGION
  FROM LATE SATURDAY NIGHT THROUGH SUNDAY AFTERNOON. ADDITIONAL
  RAINFALL AMOUNTS FROM 0.75 TO 1.5 INCHES ARE POSSIBLE AT LOWER
  ELEVATIONS WITH 2 TO 4 INCHES ACROSS HIGHER TERRAIN.

* THE PRIMARY IMPACTS WILL BE LOCALIZED PONDING OF WATER ON LOW 
  LYING ROADWAYS WITH POOR DRAINAGE...RAPID RISES ON STREAMS AND 
  CREEKS WITH SOME LIKELY EXCEEDING BANKFULL...SOME RIVER 
  FLOODING...AND POTENTIAL ROCK AND MUD SLIDES. RECENT BURN 
  SCARS WILL ALSO BE SUSCEPTIBLE TO DEBRIS FLOWS DURING PERIODS 
  OF INTENSE RAINFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$
7 follow-up statements
465 
WGUS66 KMTR 211146
FFAMTR

FLOOD WATCH
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
346 AM PST SAT JAN 21 2017

...FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE ENTIRE SAN
FRANCISCO BAY AREA AND CENTRAL COAST...

.THE THIRD IN A SERIES OF STRONG STORM SYSTEMS IS EXPECTED TO
PRODUCE PERIODS OF MODERATE TO HEAVY RAIN LATE TONIGHT THROUGH
SUNDAY MORNING. THIS ADDITIONAL RAIN ON ALREADY SATURATED SOILS
WILL LIKELY LEAD TO FLASH FLOODING OF AREA STREAMS AND RIVERS AS
WELL AS LOCAL URBAN AREAS.

CAZ006-505>513-516>518-528>530-212300-
/O.CON.KMTR.FF.A.0004.170122T0800Z-170123T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN FRANCISCO-
COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE-
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
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-
SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN ANTONIO-
SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST-
MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY
INCLUDING PINNACLES NATIONAL MONUMENT-
NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL VALLEY-
NORTHERN MONTEREY BAY-SOUTHERN MONTEREY BAY AND BIG SUR COAST-
INCLUDING THE CITIES OF...SAN FRANCISCO...TAMALPAIS-HOMESTEAD...
SAUSALITO...SANTA ROSA...SOUTH SANTA ROSA...NAPA...SAN RAFAEL...
PETALUMA...NOVATO...ROHNERT PARK...ANGWIN...
LAGUNITAS-FOREST KNOLLS...WOODACRE...OAKLAND...FREMONT...
HAYWARD...DALY CITY...BERKELEY...PACIFICA...CONCORD...ANTIOCH...
LIVERMORE...WALNUT CREEK...PLEASANTON...PITTSBURG...SAN RAMON...
BLACKHAWK...SCOTTS VALLEY...BOULDER CREEK...DAY VALLEY...
SAN JOSE...GREENFIELD...KING CITY...SALINAS...SANTA CRUZ...
WATSONVILLE...LIVE OAK...SEASIDE...MONTEREY...MARINA
346 AM PST SAT JAN 21 2017

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH
SUNDAY 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...EAST BAY
  INTERIOR VALLEYS...MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR
  MONTEREY COUNTY INCLUDING PINNACLES NATIONAL MONUMENT...NORTH
  BAY INTERIOR VALLEYS...NORTH BAY MOUNTAINS...NORTHERN MONTEREY
  BAY...NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL
  VALLEY...SAN FRANCISCO...SAN FRANCISCO BAY SHORELINE...SAN
  FRANCISCO PENINSULA COAST...SANTA CLARA VALLEY INCLUDING SAN
  JOSE...SANTA CRUZ MOUNTAINS...SANTA LUCIA MOUNTAINS AND LOS
  PADRES NATIONAL FOREST...SOUTHERN MONTEREY BAY AND BIG SUR COAST
  AND SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN ANTONIO.

* FROM LATE TONIGHT THROUGH SUNDAY AFTERNOON

* PERIODS OF HEAVY RAIN ON ALREADY SATURATED SOILS WILL IMPACT
  THE REGION FROM LATE TONIGHT THROUGH SUNDAY AFTERNOON.
  ADDITIONAL RAINFALL AMOUNTS FROM 0.75 TO 1.5 INCHES ARE POSSIBLE
  AT LOWER ELEVATIONS WITH 2 TO 5 INCHES ACROSS THE NORTH BAY AND
  COASTAL SLOPES.

* THE PRIMARY IMPACTS WILL BE LOCALIZED PONDING OF WATER ON LOW
  LYING ROADWAYS WITH POOR DRAINAGE...RAPID RISES ON STREAMS AND
  CREEKS WITH SOME LIKELY EXCEEDING BANKFULL...SOME RIVER
  FLOODING...AND POTENTIAL ROCK AND MUD SLIDES. RECENT BURN SCARS
  WILL ALSO BE SUSCEPTIBLE TO DEBRIS FLOWS DURING PERIODS OF
  INTENSE RAINFALL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$
946 
WGUS66 KMTR 212227
FFAMTR

FLOOD WATCH
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
227 PM PST SAT JAN 21 2017

...FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE ENTIRE SAN
FRANCISCO BAY AREA AND CENTRAL COAST...

.ANOTHER STRONG STORM SYSTEM IS EXPECTED TO PRODUCE PERIODS OF
MODERATE TO HEAVY RAIN LATE TONIGHT THROUGH SUNDAY MORNING. THIS
ADDITIONAL RAIN ON ALREADY SATURATED SOILS WILL LIKELY LEAD TO
FLASH FLOODING OF AREA STREAMS AND RIVERS AS WELL AS LOCAL URBAN
AREAS.

CAZ006-505>513-516>518-528>530-221200-
/O.CON.KMTR.FF.A.0004.170122T0800Z-170123T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN FRANCISCO-
COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE-
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
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-
SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN ANTONIO-
SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST-
MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY
INCLUDING PINNACLES NATIONAL MONUMENT-
NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL VALLEY-
NORTHERN MONTEREY BAY-SOUTHERN MONTEREY BAY AND BIG SUR COAST-
INCLUDING THE CITIES OF...SAN FRANCISCO...TAMALPAIS-HOMESTEAD...
SAUSALITO...SANTA ROSA...SOUTH SANTA ROSA...NAPA...SAN RAFAEL...
PETALUMA...NOVATO...ROHNERT PARK...ANGWIN...
LAGUNITAS-FOREST KNOLLS...WOODACRE...OAKLAND...FREMONT...
HAYWARD...DALY CITY...BERKELEY...PACIFICA...CONCORD...ANTIOCH...
LIVERMORE...WALNUT CREEK...PLEASANTON...PITTSBURG...SAN RAMON...
BLACKHAWK...SCOTTS VALLEY...BOULDER CREEK...DAY VALLEY...
SAN JOSE...GREENFIELD...KING CITY...SALINAS...SANTA CRUZ...
WATSONVILLE...LIVE OAK...SEASIDE...MONTEREY...MARINA
227 PM PST SAT JAN 21 2017

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM MIDNIGHT PST TONIGHT
THROUGH SUNDAY 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...EAST BAY 
  INTERIOR VALLEYS...MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR 
  MONTEREY COUNTY INCLUDING PINNACLES NATIONAL MONUMENT...NORTH 
  BAY INTERIOR VALLEYS...NORTH BAY MOUNTAINS...NORTHERN MONTEREY 
  BAY...NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL 
  VALLEY...SAN FRANCISCO...SAN FRANCISCO BAY SHORELINE...SAN 
  FRANCISCO PENINSULA COAST...SANTA CLARA VALLEY INCLUDING SAN 
  JOSE...SANTA CRUZ MOUNTAINS...SANTA LUCIA MOUNTAINS AND LOS 
  PADRES NATIONAL FOREST...SOUTHERN MONTEREY BAY AND BIG SUR 
  COAST AND SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN 
  ANTONIO. 

* FROM MIDNIGHT PST TONIGHT THROUGH SUNDAY AFTERNOON

* PERIODS OF HEAVY RAIN ON ALREADY SATURATED SOILS WILL IMPACT THE
  REGION FROM LATE TONIGHT THROUGH SUNDAY AFTERNOON. ADDITIONAL
  RAINFALL AMOUNTS FROM 1 TO 2 INCHES ARE POSSIBLE AT LOWER
  ELEVATIONS WITH 2 TO 5 INCHES ACROSS THE NORTH BAY AND COASTAL
  SLOPES.

* THE PRIMARY IMPACTS WILL BE LOCALIZED PONDING OF WATER ON LOW 
  LYING ROADWAYS WITH POOR DRAINAGE...RAPID RISES ON STREAMS AND 
  CREEKS WITH SOME LIKELY EXCEEDING BANKFULL...SOME RIVER 
  FLOODING...AND POTENTIAL ROCK AND MUD SLIDES. RECENT BURN 
  SCARS WILL ALSO BE SUSCEPTIBLE TO DEBRIS FLOWS DURING PERIODS 
  OF INTENSE RAINFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$
792 
WGUS66 KMTR 221150
FFAMTR

FLOOD WATCH
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
350 AM PST SUN JAN 22 2017

...FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE ENTIRE SAN
FRANCISCO BAY AREA AND CENTRAL COAST THOUGH THIS AFTERNOON...

.A STRONG COLD FRONT PUSHING THROUGH THE REGION WILL PRODUCE
PERIODS OF MODERATE TO HEAVY RAINFALL THROUGH THIS MORNING. IN
ADDITION, SHOWERS AND THUNDERSTORMS ANTICIPATED THIS AFTERNOON
WILL ALSO PRODUCE BRIEF HEAVY DOWNPOURS. THIS ADDITIONAL RAINFALL
ON ALREADY SATURATED SOILS WILL LIKELY LEAD TO FLASH FLOODING OF
AREA STREAMS AND RIVERS AS WELL AS LOCAL URBAN AREAS.

CAZ006-505>513-516>518-528>530-230000-
/O.CON.KMTR.FF.A.0004.000000T0000Z-170123T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN FRANCISCO-
COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE-
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
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-
SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN ANTONIO-
SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST-
MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY
INCLUDING PINNACLES NATIONAL MONUMENT-
NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL VALLEY-
NORTHERN MONTEREY BAY-SOUTHERN MONTEREY BAY AND BIG SUR COAST-
INCLUDING THE CITIES OF...SAN FRANCISCO...TAMALPAIS-HOMESTEAD...
SAUSALITO...SANTA ROSA...SOUTH SANTA ROSA...NAPA...SAN RAFAEL...
PETALUMA...NOVATO...ROHNERT PARK...ANGWIN...
LAGUNITAS-FOREST KNOLLS...WOODACRE...OAKLAND...FREMONT...
HAYWARD...DALY CITY...BERKELEY...PACIFICA...CONCORD...ANTIOCH...
LIVERMORE...WALNUT CREEK...PLEASANTON...PITTSBURG...SAN RAMON...
BLACKHAWK...SCOTTS VALLEY...BOULDER CREEK...DAY VALLEY...
SAN JOSE...GREENFIELD...KING CITY...SALINAS...SANTA CRUZ...
WATSONVILLE...LIVE OAK...SEASIDE...MONTEREY...MARINA
350 AM PST SUN JAN 22 2017

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THIS 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...EAST BAY 
  INTERIOR VALLEYS...MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR 
  MONTEREY COUNTY INCLUDING PINNACLES NATIONAL MONUMENT...NORTH 
  BAY INTERIOR VALLEYS...NORTH BAY MOUNTAINS...NORTHERN MONTEREY 
  BAY...NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL 
  VALLEY...SAN FRANCISCO...SAN FRANCISCO BAY SHORELINE...SAN 
  FRANCISCO PENINSULA COAST...SANTA CLARA VALLEY INCLUDING SAN 
  JOSE...SANTA CRUZ MOUNTAINS...SANTA LUCIA MOUNTAINS AND LOS 
  PADRES NATIONAL FOREST...SOUTHERN MONTEREY BAY AND BIG SUR 
  COAST AND SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN 
  ANTONIO. 

* THROUGH THIS AFTERNOON.

* PERIODS OF HEAVY RAIN ON ALREADY SATURATED SOILS WILL IMPACT THE
  REGION THROUGH THIS AFTERNOON. 

* THE PRIMARY IMPACTS WILL BE LOCALIZED PONDING OF WATER ON LOW 
  LYING ROADWAYS WITH POOR DRAINAGE...RAPID RISES ON STREAMS AND 
  CREEKS WITH SOME LIKELY EXCEEDING BANKFULL...SOME RIVER 
  FLOODING...AND POTENTIAL ROCK AND MUD SLIDES. RECENT BURN 
  SCARS WILL ALSO BE SUSCEPTIBLE TO DEBRIS FLOWS DURING PERIODS 
  OF INTENSE RAINFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$
914 
WGUS66 KMTR 222011
FFAMTR

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1211 PM PST SUN JAN 22 2017

...FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE ENTIRE SAN
FRANCISCO BAY AREA AND CENTRAL COAST THOUGH MONDAY EVENING...

.A COLD FRONT PUSHED THROUGH THE REGION EARLY SUNDAY MORNING
BRINING PERIODS OF MODERATE TO HEAVY RAINFALL. THE AREA IS NOW IN
THE UNSTABLE POST FRONTAL ENVIRONMENT. SHOWERS AND
THUNDERSTORMS ARE ANTICIPATED TO MOVE INLAND THIS AFTERNOON BEFORE
STRENGTHENING INTO THIS EVENING. ADDITIONAL SHOWERS AND
THUNDERSTORMS WILL MOVE THROUGH THE AREA TONIGHT AND THROUGH
MONDAY. THIS ADDITIONAL RAINFALL ON ALREADY SATURATED SOILS AND
FULL RESERVOIRS WILL LIKELY LEAD TO FLASH FLOODING OF AREA STREAMS
AND RIVERS AS WELL AS LOCALIZED URBAN AREAS. MUD/ROCK SLIDES AND
DOWNED TREES SHOULD ALSO BE EXPECTED... ESPECIALLY DURING INTENSE
BURSTS OF RAINFALL THAT OCCUR DURING THUNDERSTORMS.

CAZ006-505>513-516>518-528>530-240200-
/O.EXT.KMTR.FF.A.0004.000000T0000Z-170124T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN FRANCISCO-
COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE-
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
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-
SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN ANTONIO-
SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST-
MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY
INCLUDING PINNACLES NATIONAL MONUMENT-
NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL VALLEY-
NORTHERN MONTEREY BAY-SOUTHERN MONTEREY BAY AND BIG SUR COAST-
INCLUDING THE CITIES OF...SAN FRANCISCO...TAMALPAIS-HOMESTEAD...
SAUSALITO...SANTA ROSA...SOUTH SANTA ROSA...NAPA...SAN RAFAEL...
PETALUMA...NOVATO...ROHNERT PARK...ANGWIN...
LAGUNITAS-FOREST KNOLLS...WOODACRE...OAKLAND...FREMONT...
HAYWARD...DALY CITY...BERKELEY...PACIFICA...CONCORD...ANTIOCH...
LIVERMORE...WALNUT CREEK...PLEASANTON...PITTSBURG...SAN RAMON...
BLACKHAWK...SCOTTS VALLEY...BOULDER CREEK...DAY VALLEY...
SAN JOSE...GREENFIELD...KING CITY...SALINAS...SANTA CRUZ...
WATSONVILLE...LIVE OAK...SEASIDE...MONTEREY...MARINA
1211 PM PST SUN JAN 22 2017

...FLASH FLOOD WATCH NOW IN EFFECT THROUGH MONDAY AFTERNOON...

THE FLASH FLOOD WATCH IS NOW IN EFFECT 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...EAST BAY 
  INTERIOR VALLEYS...MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR 
  MONTEREY COUNTY INCLUDING PINNACLES NATIONAL MONUMENT...NORTH 
  BAY INTERIOR VALLEYS...NORTH BAY MOUNTAINS...NORTHERN MONTEREY 
  BAY...NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL 
  VALLEY...SAN FRANCISCO...SAN FRANCISCO BAY SHORELINE...SAN 
  FRANCISCO PENINSULA COAST...SANTA CLARA VALLEY INCLUDING SAN 
  JOSE...SANTA CRUZ MOUNTAINS...SANTA LUCIA MOUNTAINS AND LOS 
  PADRES NATIONAL FOREST...SOUTHERN MONTEREY BAY AND BIG SUR 
  COAST AND SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN 
  ANTONIO. 

* THROUGH MONDAY AFTERNOON

* PERIODS OF HEAVY RAIN ON ALREADY SATURATED SOILS AND FULL
  RESERVOIRS WILL IMPACT THE REGION BEGINNING THIS AFTERNOON AND
  LASTING THROUGH MONDAY.

* THE PRIMARY IMPACTS WILL BE LOCALIZED PONDING OF WATER ON LOW 
  LYING ROADWAYS WITH POOR DRAINAGE...RAPID RISES ON STREAMS AND 
  CREEKS WITH SOME LIKELY EXCEEDING BANKFULL...SOME RIVER 
  FLOODING...AND POTENTIAL ROCK AND MUD SLIDES. RECENT BURN 
  SCARS WILL ALSO BE SUSCEPTIBLE TO DEBRIS FLOWS DURING PERIODS 
  OF INTENSE RAINFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$
DRP
381 
WGUS66 KMTR 231046
FFAMTR

FLOOD WATCH
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
246 AM PST MON JAN 23 2017

...FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE ENTIRE SAN
FRANCISCO BAY AREA AND CENTRAL COAST THROUGH MONDAY EVENING...

.SCATTERED TO NUMEROUS SHOWERS AND POSSIBLE THUNDERSTORMS WILL
IMPACT THE REGION THROUGH THIS EVENING. ANY ADDITIONAL RAINFALL,
ESPECIALLY BRIEF HEAVY DOWNPOURS IN STRONGER SHOWERS OR
THUNDERSTORMS, WILL LIKELY RESULT IN FLASH FLOODING OF AREA
STREAMS AND RIVERS AS WELL AS LOCALIZED URBAN AREAS. MUD/ROCK
SLIDES AND DOWNED TREES SHOULD ALSO BE EXPECTED, ESPECIALLY DURING
INTENSE BURSTS OF RAINFALL THAT OCCUR DURING ANY THUNDERSTORMS.

CAZ006-505>513-516>518-528>530-240200-
/O.CON.KMTR.FF.A.0004.000000T0000Z-170124T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN FRANCISCO-
COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE-
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
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-
SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN ANTONIO-
SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST-
MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY
INCLUDING PINNACLES NATIONAL MONUMENT-
NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL VALLEY-
NORTHERN MONTEREY BAY-SOUTHERN MONTEREY BAY AND BIG SUR COAST-
INCLUDING THE CITIES OF...SAN FRANCISCO...TAMALPAIS-HOMESTEAD...
SAUSALITO...SANTA ROSA...SOUTH SANTA ROSA...NAPA...SAN RAFAEL...
PETALUMA...NOVATO...ROHNERT PARK...ANGWIN...
LAGUNITAS-FOREST KNOLLS...WOODACRE...OAKLAND...FREMONT...
HAYWARD...DALY CITY...BERKELEY...PACIFICA...CONCORD...ANTIOCH...
LIVERMORE...WALNUT CREEK...PLEASANTON...PITTSBURG...SAN RAMON...
BLACKHAWK...SCOTTS VALLEY...BOULDER CREEK...DAY VALLEY...
SAN JOSE...GREENFIELD...KING CITY...SALINAS...SANTA CRUZ...
WATSONVILLE...LIVE OAK...SEASIDE...MONTEREY...MARINA
246 AM PST MON JAN 23 2017

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

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...EAST BAY 
  INTERIOR VALLEYS...MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR 
  MONTEREY COUNTY INCLUDING PINNACLES NATIONAL MONUMENT...NORTH 
  BAY INTERIOR VALLEYS...NORTH BAY MOUNTAINS...NORTHERN MONTEREY 
  BAY...NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL 
  VALLEY...SAN FRANCISCO...SAN FRANCISCO BAY SHORELINE...SAN 
  FRANCISCO PENINSULA COAST...SANTA CLARA VALLEY INCLUDING SAN 
  JOSE...SANTA CRUZ MOUNTAINS...SANTA LUCIA MOUNTAINS AND LOS 
  PADRES NATIONAL FOREST...SOUTHERN MONTEREY BAY AND BIG SUR 
  COAST AND SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN 
  ANTONIO. 

* THROUGH THIS EVENING.

* PERIODS OF HEAVY RAIN, POTENTIALLY HEAVY AT TIMES, ON ALREADY
  SATURATED SOILS AND FULL RESERVOIRS WILL IMPACT THE REGION
  THROUGH THIS EVENING.

* THE PRIMARY IMPACTS WILL BE LOCALIZED PONDING OF WATER ON LOW 
  LYING ROADWAYS WITH POOR DRAINAGE...RAPID RISES ON STREAMS AND 
  CREEKS WITH SOME LIKELY EXCEEDING BANKFULL...SOME RIVER 
  FLOODING...AND POTENTIAL ROCK AND MUD SLIDES. RECENT BURN 
  SCARS WILL ALSO BE SUSCEPTIBLE TO DEBRIS FLOWS DURING PERIODS 
  OF INTENSE RAINFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$
689 
WGUS66 KMTR 231053 CCA
FFAMTR

FLOOD WATCH...CORRECTED
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
253 AM PST MON JAN 23 2017

...FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE ENTIRE SAN
FRANCISCO BAY AREA AND CENTRAL COAST THROUGH MONDAY EVENING...

.SCATTERED TO NUMEROUS SHOWERS AND POSSIBLE THUNDERSTORMS WILL
IMPACT THE REGION THROUGH THIS EVENING. ANY ADDITIONAL RAINFALL,
ESPECIALLY BRIEF HEAVY DOWNPOURS IN STRONGER SHOWERS OR
THUNDERSTORMS, WILL LIKELY RESULT IN FLASH FLOODING OF AREA
STREAMS AND RIVERS AS WELL AS LOCALIZED URBAN AREAS. MUD/ROCK
SLIDES AND DOWNED TREES SHOULD ALSO BE EXPECTED, ESPECIALLY DURING
INTENSE BURSTS OF RAINFALL THAT OCCUR DURING ANY THUNDERSTORMS.

CAZ006-505>513-516>518-528>530-232300-
/O.COR.KMTR.FF.A.0004.000000T0000Z-170124T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN FRANCISCO-
COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE-
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
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-
SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN ANTONIO-
SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST-
MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY
INCLUDING PINNACLES NATIONAL MONUMENT-
NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL VALLEY-
NORTHERN MONTEREY BAY-SOUTHERN MONTEREY BAY AND BIG SUR COAST-
INCLUDING THE CITIES OF...SAN FRANCISCO...TAMALPAIS-HOMESTEAD...
SAUSALITO...SANTA ROSA...SOUTH SANTA ROSA...NAPA...SAN RAFAEL...
PETALUMA...NOVATO...ROHNERT PARK...ANGWIN...
LAGUNITAS-FOREST KNOLLS...WOODACRE...OAKLAND...FREMONT...
HAYWARD...DALY CITY...BERKELEY...PACIFICA...CONCORD...ANTIOCH...
LIVERMORE...WALNUT CREEK...PLEASANTON...PITTSBURG...SAN RAMON...
BLACKHAWK...SCOTTS VALLEY...BOULDER CREEK...DAY VALLEY...
SAN JOSE...GREENFIELD...KING CITY...SALINAS...SANTA CRUZ...
WATSONVILLE...LIVE OAK...SEASIDE...MONTEREY...MARINA
253 AM PST MON JAN 23 2017

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

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...EAST BAY 
  INTERIOR VALLEYS...MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR 
  MONTEREY COUNTY INCLUDING PINNACLES NATIONAL MONUMENT...NORTH 
  BAY INTERIOR VALLEYS...NORTH BAY MOUNTAINS...NORTHERN MONTEREY 
  BAY...NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL 
  VALLEY...SAN FRANCISCO...SAN FRANCISCO BAY SHORELINE...SAN 
  FRANCISCO PENINSULA COAST...SANTA CLARA VALLEY INCLUDING SAN 
  JOSE...SANTA CRUZ MOUNTAINS...SANTA LUCIA MOUNTAINS AND LOS 
  PADRES NATIONAL FOREST...SOUTHERN MONTEREY BAY AND BIG SUR 
  COAST AND SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN 
  ANTONIO. 

* THROUGH THIS EVENING.

* PERIODS OF HEAVY RAIN ON ALREADY SATURATED SOILS AND FULL
  RESERVOIRS WILL IMPACT THE REGION THROUGH THIS EVENING.

* THE PRIMARY IMPACTS WILL BE LOCALIZED PONDING OF WATER ON LOW 
  LYING ROADWAYS WITH POOR DRAINAGE...RAPID RISES ON STREAMS AND 
  CREEKS WITH SOME LIKELY EXCEEDING BANKFULL...SOME RIVER 
  FLOODING...AND POTENTIAL ROCK AND MUD SLIDES. RECENT BURN 
  SCARS WILL ALSO BE SUSCEPTIBLE TO DEBRIS FLOWS DURING PERIODS 
  OF INTENSE RAINFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$
915 
WGUS66 KMTR 232217
FFAMTR

FLOOD WATCH
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
217 PM PST MON JAN 23 2017

...FLASH FLOOD WATCH IS CANCELLED...

.SHOWERS WILL CONTINUE THIS EVENING AND OVERNIGHT. HOWEVER
WIDESPREAD HEAVY RAIN IS NO LONGER EXPECTED.

CAZ006-505>513-516>518-528>530-232330-
/O.CAN.KMTR.FF.A.0004.000000T0000Z-170124T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN FRANCISCO-
COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE-
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
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-
SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN ANTONIO-
SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST-
MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY
INCLUDING PINNACLES NATIONAL MONUMENT-
NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL VALLEY-
NORTHERN MONTEREY BAY-SOUTHERN MONTEREY BAY AND BIG SUR COAST-
INCLUDING THE CITIES OF...SAN FRANCISCO...TAMALPAIS-HOMESTEAD...
SAUSALITO...SANTA ROSA...SOUTH SANTA ROSA...NAPA...SAN RAFAEL...
PETALUMA...NOVATO...ROHNERT PARK...ANGWIN...
LAGUNITAS-FOREST KNOLLS...WOODACRE...OAKLAND...FREMONT...
HAYWARD...DALY CITY...BERKELEY...PACIFICA...CONCORD...ANTIOCH...
LIVERMORE...WALNUT CREEK...PLEASANTON...PITTSBURG...SAN RAMON...
BLACKHAWK...SCOTTS VALLEY...BOULDER CREEK...DAY VALLEY...
SAN JOSE...GREENFIELD...KING CITY...SALINAS...SANTA CRUZ...
WATSONVILLE...LIVE OAK...SEASIDE...MONTEREY...MARINA
217 PM PST MON JAN 23 2017

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR A PORTION OF NORTHERN CALIFORNIA HAS
BEEN CANCELLED. SHOWERS WILL CONTINUE THIS EVENING AND OVERNIGHT
BUT WIDESPREAD HEAVY RAIN IS NO LONGER EXPECTED. THEREFORE THE
FLASH FLOOD WATCH HAS BEEN CANCELLED.

$$

What forecasters said that day

The local office's own words before this flash 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 flash flood watch went out at Jan 20, 9:21 AM PST, 4 hours 6 minutes earlier.

Area forecast discussion, Jan 20, 9:21 AM PST, 4 hours 6 minutes before
Area Forecast Discussion
National Weather Service San Francisco Bay Area
921 AM PST Fri Jan 20 2017

.SYNOPSIS...A cold front is currently exiting the district but
scattered showers are expected to continue today in the unstable
airmass behind the front. In addition, isolated thunderstorms
will be possible. A few showers will then linger into Saturday
morning with another, likely wetter system arriving late Saturday
into Sunday. Given the antecedent conditions from recent rainfall,
this system will have the potential to result in additional
flooding concerns across portions of the region. Showers will then
linger behind this cold front into Monday with dry conditions
returning by Tuesday.

&&

.DISCUSSION...as of 9:21 AM PST Friday...A fast-moving but robust
cold front moved across the district overnight and this morning,
bringing moderate to heavy rains and gusty winds. Right now, the
front has exited the CWA, but there are showers behind the front
in the unstable airmass. KMUX radar is showing several impressive
echoes just off the San Mateo coast and moving across towards the
San Francisco Bay. This shower activity will persist through the
day and gradually taper off overnight. Wind speeds have decreased
and the wind advisory will be allowed to expire at 10 am, if not
cancelled before then.

By Saturday late morning/early afternoon, showers will likely be
ended with a bit of a break in precipitation for a good portion
of the region.

The next system in this series remains on track to impact the
area from late Saturday into Sunday morning. This system appears
to have a deeper moisture tap with PWAT values forecast to range
between 1 to 1.25 inches. Given this, expecting rainfall amounts
to be greater than the previous two systems which will likely
lead to a greater threat for flooding issues. Additional rainfall
amounts from Saturday into Sunday will range from 0.75 to 1.25
inches in most urban areas and upwards of 2 inches in the North
Bay Valleys. Meanwhile, the coastal ranges and North Bay Mountains
will likely see 2 to 4 inches with isolated amounts upwards of 6
inches. Thus, a Flash Flood Watch will likely be considered for
portions of the district if the forecast models remain consistent,
especially considering a few creeks went to flood stage with last
night's storm. Along with the additional rainfall, southerly winds
will also increase and become gusty at times ahead of the frontal
boundary that will sweep through late Saturday night into early
Sunday morning.

Showers will then likely linger into Sunday night and even through
much of the day Monday as the main mid/upper level low drops
southward down along the northern California coast. By Tuesday, the
trough will shift inland while a ridge begins to develop off of
the West Coast. This ridge will maintain dry weather conditions
through the remainder of next week with temperatures near seasonal
averages.

&&

.AVIATION...As of 5:03 AM PST Friday...A very strong and fast moving
cold front is pressing eastward across the forecast area this morning
accompanied by heavy rain and wind. Pressure falls along the coastal
waters and over land have been commonly 2-3 mb per hour since late
last evening /pressure falling rapidly/. Cold unstable air is quickly
moving in this morning, expect a continuation of heavy showers and
t-storm development through this morning and afternoon. IR imagery
shows lots of open cellular clouds to our W-NW, a signature of plenty
instability to arrive today.

Vicinity of KSFO....Airport weather warning valid through 15z, may
need to extend warning if winds remain strong and gusty. Model guidance
indicates possible lull then re-energized westerly winds developing
later this morning into the afternoon. Expect downpours and possible
additional t-storms with reduced visibilities and ceilings to MVFR
possibly briefly IFR visibilities.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Strong and gusty southeast winds prior to
cold front moving through early this morning. MVFR possibly briefly
IFR visibilities in downpours and t-storms.

&&

.MARINE...as of 8:56 AM PST Friday...Strong southerly gale force
winds will continue across the coastal waters through this morning
ahead of an approaching cold front. As a result rough and
hazardous seas will continue through today. After the front passes
this morning winds will shift to the west but remain moderate and
gusty. Winds will increase again Saturday night as another frontal
system approaches. Very large swells arrive Friday afternoon with
swell heights building to 25 to 30 feet Friday night and Saturday.
Rogue waves of 30 feet or greater are possible during this
timeframe.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tday...Wind Advisory...CAZ006-505-507-509-511-512-517-518-529-530
             High Surf Warning...CAZ006-505-509-529-530
             SCA...Mry Bay
             SCA...Pt Arena to Pt Reyes 0-10 nm
             SCA...Pt Reyes to Pigeon Pt 0-10 nm
             SCA...Pigeon Pt to Pt Pinos 0-10 nm
             SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
             SCA...Pt Arena to Pigeon Pt 10-60 nm
             SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
             SCA...Rough Bar Advisory for SF Bar
             SCA...SF Bay

&&

PUBLIC FORECAST: Sims
AVIATION: Canepa
MARINE: CW

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The office that day

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

IssuedProductOfficeCountiesLasted
Jan 19, 9:01 PM PSTGale WarningMTR10 hr
Jan 19, 9:01 PM PSTSmall Craft AdvisoryMTR42 hr
Jan 20, 1:26 AM PSTAreal Flood AdvisoryMTRMarin, Sonoma3 hr
Jan 20, 3:02 AM PSTSpecial Marine WarningMTR43 min
Jan 20, 3:39 AM PSTSpecial Weather StatementMTRSan Mateo36 min
Jan 20, 4:07 AM PSTSpecial Marine WarningMTR23 min
Jan 20, 4:14 AM PSTSpecial Weather StatementMTRAlameda, Contra Costa, San Mateo31 min
Jan 20, 4:49 AM PSTFlash Flood WarningMTRSonoma4 hr
Jan 20, 5:27 AM PSTAreal Flood AdvisoryMTRSan Mateo, Santa Clara, Santa Cruz3 hr
Jan 20, 6:38 AM PSTFlash Flood WarningMTRSanta Cruz6 hr
Jan 20, 7:08 AM PSTFlash Flood WarningMTRSanta Clara6 hr
Jan 20, 7:31 AM PSTAreal Flood WarningMTRSanta Cruz12 hr
Jan 20, 7:55 AM PSTAreal Flood WarningMTRSonoma18 hr
Jan 20, 12:20 PM PSTFlash Flood WarningMTRSan Benito4 hr
Jan 20, 12:51 PM PSTHigh Wind WatchMTRAlameda, Contra Costa, Marin, Monterey, Napa, San Benito and 5 more15 hr
Jan 20, 2:33 PM PSTGale WatchMTR14 hr
Jan 20, 2:33 PM PSTGale WarningMTR42 hr
Jan 20, 3:51 PM PSTAreal Flood AdvisoryMTRSan Benito, Santa Clara70 hr
Jan 20, 3:56 PM PSTAreal Flood WarningMTRSan Benito, Santa Clara72 hr

Nearby

Flash Flood Watches in California, 2017Every flash flood watch in 2017

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.