Alert archive / California / Red Flag Warnings in 2011

Red Flag Warning 4, NWS San Francisco Bay Area, CA

October 31, 2011

NWS San Francisco Bay Area, CA issued this red flag warning at Oct 31, 2011, 9:52 AM PDT. It took effect at Nov 1, 2011, 6:00 AM PDT. It was in force for 27 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Oct 31, 2011, 9:52 AM PDT (16:52 UTC)
In effect from
Nov 1, 2011, 6:00 AM PDT
Expired
Nov 2, 2011, 9:00 AM PDT
In force
27 hr
Issued by
NWS San Francisco Bay Area, CA

The text

As transmitted, in the capitals the NWS used until 2016.

704 
WWUS86 KMTR 311652
RFWMTR

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
952 AM PDT MON OCT 31 2011

...RED FLAG WARNING IN EFFECT FOR THE NORTH AND EAST BAY
HILLS FROM 6 AM TUESDAY MORNING THROUGH 6 AM WEDNESDAY MORNING...

.AN UPPER LEVEL TROUGH WILL DIG INTO THE GREAT BASIN TONIGHT INTO
EARLY TUESDAY. IN THE WAKE OF THIS TROUGH A SURFACE HIGH WILL
RAPIDLY BUILD OVER THE PACIFIC NORTHWEST AND NORTHERN NEVADA. THIS
WILL RESULT IN MODERATE TO STRONG NORTH TO NORTHEAST WINDS OVER
THE NORTH AND EAST BAY HILLS FROM TUESDAY MORNING THROUGH WEDNESDAY
MORNING. AT THE SAME TIME...MUCH DRIER AIR WILL MOVE INTO THE
AREA...RESULTING IN VERY POOR TO NO RELATIVE HUMIDITY RECOVERIES
TUESDAY NIGHT ACROSS THE HILLS OF THE NORTH AND EAST BAY. WINDS
ARE FORECAST TO RAPIDLY DIMINISH AFTER SUNRISE WEDNESDAY AS
ONSHORE FLOW RETURNS.

CAZ507-511-312300-
/O.UPG.KMTR.FW.A.0004.111101T1300Z-111102T1800Z/
/O.NEW.KMTR.FW.W.0004.111101T1300Z-111102T1300Z/
NORTH BAY MOUNTAINS-EAST BAY HILLS AND DIABLO RANGE-
952 AM PDT MON OCT 31 2011

...RED FLAG WARNING IN EFFECT FROM 6 AM TUESDAY TO 6 AM PDT
WEDNESDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE NORTH AND
EAST BAY HILLS...

THE NATIONAL WEATHER SERVICE IN SAN FRANCISCO HAS ISSUED A RED
FLAG WARNING FOR WIND AND LOW RELATIVE HUMIDITY...WHICH IS IN
EFFECT FROM 6 AM TUESDAY TO 6 AM PDT WEDNESDAY. 

* AFFECTED AREA...THE NORTH AND EAST BAY HILLS ABOVE 1000 FEET.

* WINDS...NORTH TO NORTHEAST WINDS 15 TO 25 MPH WITH FREQUENT
  GUSTS 35 TO 40 MPH. STRONGEST WINDS EXPECTED DURING THE PEAK
  HEATING HOURS OF TUESDAY AFTERNOON AND EVENING.

* RELATIVE HUMIDITY...BETWEEN 30-45 PERCENT EARLY TUESDAY MORNING
  LOWER TO 15-20% TUESDAY AFTERNOON WITH LITTLE OR NO RELATIVE
  HUMIDITY RECOVERY THROUGH WEDNESDAY MORNING.

* IMPACTS...ANY FIRE STARTS DURING THE PERIOD OF STRONG WINDS AND
  LOW HUMIDITY WILL BE DIFFICULT TO SUPPRESS WITH RAPID RATES OF
  SPREAD. PRESCRIBED AND BACKYARD BURNERS SHOULD USE EXTREME
  CAUTION DURING THIS RED FLAG EVENT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS
ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF
STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL
CREATE EXPLOSIVE FIRE GROWTH POTENTIAL.

&&

$$

FOR MORE INFORMATION FROM NOAA/NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SANFRANCISCO (ALL LOWER CASE)
6 follow-up statements
437 
WWUS86 KMTR 312117
RFWMTR

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
217 PM PDT MON OCT 31 2011

...RED FLAG WARNING IN EFFECT FOR THE NORTH AND EAST BAY HILLS
FROM 6 AM TUESDAY MORNING THROUGH 6 AM WEDNESDAY MORNING...

.AN UPPER LEVEL TROUGH WILL DIG INTO THE GREAT BASIN TONIGHT INTO
EARLY TUESDAY. IN THE WAKE OF THIS TROUGH A SURFACE HIGH WILL
RAPIDLY BUILD OVER THE PACIFIC NORTHWEST AND NORTHERN NEVADA.
THIS WILL RESULT IN MODERATE TO STRONG NORTH TO NORTHEAST WINDS
OVER THE NORTH AND EAST BAY HILLS FROM TUESDAY MORNING THROUGH
WEDNESDAY MORNING. AT THE SAME TIME...MUCH DRIER AIR WILL MOVE
INTO THE AREA...RESULTING IN VERY POOR TO NO RELATIVE HUMIDITY
RECOVERIES TUESDAY NIGHT ACROSS THE HILLS OF THE NORTH AND EAST
BAY. WINDS ARE FORECAST TO RAPIDLY DIMINISH AFTER SUNRISE
WEDNESDAY AS ONSHORE FLOW RETURNS.

CAZ507-511-011300-
/O.CON.KMTR.FW.W.0004.111101T1300Z-111102T1300Z/
NORTH BAY MOUNTAINS-EAST BAY HILLS AND DIABLO RANGE-
217 PM PDT MON OCT 31 2011

...RED FLAG WARNING REMAINS IN EFFECT FROM 6 AM TUESDAY TO 6 AM
PDT WEDNESDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE NORTH
AND EAST BAY HILLS...

A RED FLAG WARNING REMAINS IN EFFECT FROM 6 AM TUESDAY TO 6 AM
PDT WEDNESDAY. 

* AFFECTED AREA...THE NORTH AND EAST BAY HILLS ABOVE 1000 FEET.
  THE STRONGEST WINDS WILL INITIALLY ARRIVE IN THE NAPA COUNTY
  HILLS BY EARLY TUESDAY AND THEN SPREAD INTO THE EAST BAY HILLS
  DURING THE DAY TUESDAY. BY LATER TUESDAY AFTERNOON AND EVENING
  THE OFFSHORE WINDS WILL REACH THE COASTAL HILLS OF MARIN AND
  SONOMA COUNTY.

* WINDS...NORTH TO NORTHEAST WINDS 15 TO 25 MPH WITH FREQUENT
  GUSTS 35 TO 40 MPH. STRONGEST WINDS EXPECTED DURING THE PEAK
  HEATING HOURS OF TUESDAY AFTERNOON AND EVENING.

* RELATIVE HUMIDITY...BETWEEN 30-45 PERCENT EARLY TUESDAY MORNING
  LOWERING TO 15-20% TUESDAY AFTERNOON WITH LITTLE OR NO RELATIVE
  HUMIDITY RECOVERY THROUGH WEDNESDAY MORNING.

* IMPACTS...ANY FIRE STARTS DURING THE PERIOD OF STRONG WINDS 
  AND LOW HUMIDITY WILL BE DIFFICULT TO SUPPRESS WITH RAPID 
  RATES OF SPREAD. PRESCRIBED AND BACKYARD BURNERS SHOULD USE 
  EXTREME CAUTION DURING THIS RED FLAG EVENT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS
ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF
STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL
CREATE EXPLOSIVE FIRE GROWTH POTENTIAL.

&&

$$

FOR MORE INFORMATION FROM NOAA/NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SANFRANCISCO (ALL LOWER CASE)
219 
WWUS86 KMTR 011116
RFWMTR

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
416 AM PDT TUE NOV 1 2011

...RED FLAG WARNING IN EFFECT FOR THE NORTH AND EAST BAY HILLS
FROM THROUGH 6 AM WEDNESDAY MORNING...

.STRONG NORTHERLY WINDS ARE ALREADY DEVELOPING ACROSS THE NORTH
AND EAST BAY HILLS EARLY THIS MORNING. NORTH TO NORTHEAST WINDS
WILL CONTINUE TO INCREASE THROUGH THE DAY AS HUMIDITY VALUES
CONTINUE TO DRY OUT. THE STRONGEST WINDS WILL END BY THIS EVENING
BUT VERY DRY AIR WILL STAY IN PLACE AT LEAST THROUGH WEDNESDAY MORNING.

CAZ507-511-012315-
/O.CON.KMTR.FW.W.0004.111101T1300Z-111102T1300Z/
NORTH BAY MOUNTAINS-EAST BAY HILLS AND DIABLO RANGE-
416 AM PDT TUE NOV 1 2011

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 AM PDT WEDNESDAY
FOR WIND AND LOW RELATIVE HUMIDITY FOR THE NORTH AND EAST BAY
HILLS...

A RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 AM PDT WEDNESDAY. 

* AFFECTED AREA...THE NORTH AND EAST BAY HILLS ABOVE 1000 FEET.
  THE STRONGEST WINDS WILL INITIALLY ARRIVE IN THE NAPA COUNTY
  HILLS EARLY THIS MORNING AND THEN SPREAD INTO THE EAST BAY HILLS
  DURING THE MID-MORNING HOURS. BY THIS AFTERNOON THE OFFSHORE
  WINDS WILL REACH THE COASTAL HILLS OF MARIN AND SONOMA COUNTY.

* WINDS...NORTH 15 TO 25 MPH WITH FREQUENT GUSTS 35 TO 40 MPH.

* RELATIVE HUMIDITY...30 TO 40 PERCENT AT SUNRISE...LOWERING 12 TO
  25 PERCENT THROUGH THE DAY WITH LITTLE OR NO HUMIDITY RECOVERY TONIGHT.

* IMPACTS...ANY FIRE STARTS DURING THE PERIOD OF STRONG WINDS 
  AND LOW HUMIDITY WILL BE DIFFICULT TO SUPPRESS WITH RAPID 
  RATES OF SPREAD. PRESCRIBED AND BACKYARD BURNERS SHOULD USE 
  EXTREME CAUTION DURING THIS RED FLAG EVENT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS
ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF
STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL
CREATE EXPLOSIVE FIRE GROWTH POTENTIAL.

&&

$$

FOR MORE INFORMATION FROM NOAA/NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SANFRANCISCO (ALL LOWER CASE)
926 
WWUS86 KMTR 012317
RFWMTR

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
417 PM PDT TUE NOV 1 2011

...RED FLAG WARNING IN EFFECT FOR THE NORTH AND EAST BAY HILLS
FROM THROUGH 6 AM WEDNESDAY MORNING...

.STRONG NORTHERLY WINDS WILL CONTINUE ACROSS THE NORTH AND EAST
BAY HILLS THROUGH THIS AFTERNOON AND EARLY EVENING AS HUMIDITY
VALUES CONTINUE TO DROP. WINDS WILL GRADUALLY DIMINISH OVERNIGHT
BUT VERY DRY AIR WILL STAY IN PLACE AT LEAST THROUGH WEDNESDAY
MORNING.

CAZ507-511-020730-
/O.CON.KMTR.FW.W.0004.000000T0000Z-111102T1300Z/
NORTH BAY MOUNTAINS-EAST BAY HILLS AND DIABLO RANGE-
417 PM PDT TUE NOV 1 2011

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 AM PDT WEDNESDAY
FOR WIND AND LOW RELATIVE HUMIDITY FOR THE NORTH AND EAST BAY
HILLS...

A RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 AM PDT WEDNESDAY. 

* AFFECTED AREA...THE NORTH AND EAST BAY HILLS ABOVE 1000 FEET.
  STRONG WINDS WILL CONTINUE ACROSS THE NORTH AND EAST BAY HILLS
  THROUGH THIS AFTERNOON AND EARLY EVENING AS HUMIDITY VALUES
  CONTINUE TO DROP. WINDS WILL GRADUALLY DIMINISH OVERNIGHT.

* WINDS...NORTH 15 TO 25 MPH WITH GUSTS UP TO 45 MPH.

* RELATIVE HUMIDITY...AS LOW AS 15 PERCENT.

* IMPACTS...ANY FIRE STARTS DURING THE PERIOD OF STRONG WINDS 
  AND LOW HUMIDITY WILL BE DIFFICULT TO SUPPRESS WITH RAPID 
  RATES OF SPREAD. PRESCRIBED AND BACKYARD BURNERS SHOULD USE 
  EXTREME CAUTION DURING THIS RED FLAG EVENT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS
ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF
STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL
CREATE EXPLOSIVE FIRE GROWTH POTENTIAL.

&&

$$

FOR MORE INFORMATION FROM NOAA/NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SANFRANCISCO (ALL LOWER CASE)
831 
WWUS86 KMTR 012319 AAA
RFWMTR

URGENT - FIRE WEATHER MESSAGE...UPDATED
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
419 PM PDT TUE NOV 1 2011

...RED FLAG WARNING IN EFFECT FOR THE NORTH AND EAST BAY HILLS
FROM THROUGH 6 AM WEDNESDAY MORNING...

.STRONG NORTHERLY WINDS WILL CONTINUE ACROSS THE NORTH AND EAST
BAY HILLS THROUGH THIS AFTERNOON AND EARLY EVENING AS HUMIDITY
VALUES CONTINUE TO DROP. WINDS WILL GRADUALLY DIMINISH OVERNIGHT
BUT VERY DRY AIR WILL STAY IN PLACE AT LEAST THROUGH WEDNESDAY
MORNING.

CAZ507-511-021300-
/O.CON.KMTR.FW.W.0004.000000T0000Z-111102T1300Z/
NORTH BAY MOUNTAINS-EAST BAY HILLS AND DIABLO RANGE-
419 PM PDT TUE NOV 1 2011

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 AM PDT WEDNESDAY
FOR WIND AND LOW RELATIVE HUMIDITY FOR THE NORTH AND EAST BAY
HILLS...

A RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 AM PDT WEDNESDAY. 

* AFFECTED AREA...THE NORTH AND EAST BAY HILLS ABOVE 1000 FEET. 
  STRONG WINDS WILL CONTINUE ACROSS THE NORTH AND EAST BAY HILLS 
  THROUGH THIS AFTERNOON AND EARLY EVENING AS HUMIDITY VALUES 
  CONTINUE TO DROP. WINDS WILL GRADUALLY DIMINISH OVERNIGHT. 

* WINDS...NORTH 15 TO 25 MPH WITH GUSTS UP TO 45 MPH.

* RELATIVE HUMIDITY...AS LOW AS 15 PERCENT.

* IMPACTS...ANY FIRE STARTS DURING THE PERIOD OF STRONG WINDS 
  AND LOW HUMIDITY WILL BE DIFFICULT TO SUPPRESS WITH RAPID 
  RATES OF SPREAD. PRESCRIBED AND BACKYARD BURNERS SHOULD USE 
  EXTREME CAUTION DURING THIS RED FLAG EVENT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS
ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF
STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL
CREATE EXPLOSIVE FIRE GROWTH POTENTIAL.

&&

$$

FOR MORE INFORMATION FROM NOAA/NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SANFRANCISCO (ALL LOWER CASE)
002 
WWUS86 KMTR 021224
RFWMTR

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
524 AM PDT WED NOV 2 2011

.GUSTY NORTHEAST WINDS WILL CONTINUE THROUGH THE EARLY MORNING
HOURS ALONG WITH VERY DRY AIR. WINDS WILL DECREASE AFTER MID
MORNING AND BECOME ONSHORE BY LATE AFTERNOON AND THIS EVENING.

CAZ507-511-021600-
/O.EXT.KMTR.FW.W.0004.000000T0000Z-111102T1600Z/
NORTH BAY MOUNTAINS-EAST BAY HILLS AND DIABLO RANGE-
524 AM PDT WED NOV 2 2011

...RED FLAG WARNING NOW IN EFFECT UNTIL 9 AM PDT THIS MORNING FOR
GUSTY WINDS AND LOW HUMIDITY FOR THE NORTH AND EAST BAY HILLS...

THE RED FLAG WARNING IS NOW IN EFFECT UNTIL 9 AM PDT THIS
MORNING. 

* AFFECTED AREA...THE NORTH AND EAST BAY HILLS ABOVE 1000 FEET.
  GUSTY WINDS WILL CONTINUE ACROSS THE NORTH AND EAST BAY HILLS
  THROUGH THE EARLY MORNING HOURS ALONG WITH VERY LOW HUMIDITY
  VALUES. WINDS WILL DECREASE AFTER MID MORNING AND BECOME ONSHORE
  BY LATE AFTERNOON AND THIS EVENING.

* WINDS...NORTH TO NORTHEAST 10 TO 20 MPH WITH GUSTS UP TO 30 MPH.

* RELATIVE HUMIDITY...AS LOW AS 15 PERCENT.

* IMPACTS...ANY FIRE STARTS DURING THE PERIOD OF STRONG WINDS 
  AND LOW HUMIDITY WILL BE DIFFICULT TO SUPPRESS WITH RAPID 
  RATES OF SPREAD. PRESCRIBED AND BACKYARD BURNERS SHOULD USE 
  EXTREME CAUTION DURING THIS RED FLAG EVENT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS
ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF
STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL
CREATE EXPLOSIVE FIRE GROWTH POTENTIAL.

&&

$$

FOR MORE INFORMATION FROM NOAA/NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SANFRANCISCO (ALL LOWER CASE)
796 
WWUS86 KMTR 021600
RFWMTR

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
900 AM PDT WED NOV 2 2011

...RED FLAG WARNING EXPIRES AT 9 AM THIS MORNING FOR THE NORTH AND
EAST BAY HILLS...

.THE PERIOD OF STRONGEST WINDS HAS PEAKED AND WIND SPEEDS WILL
GRADUALLY DECREASE THROUGH THE REST OF THIS MORNING BEFORE WINDS
SWITCH DIRECTION AND TURN ONSHORE.

CAZ507-511-021700-
/O.EXP.KMTR.FW.W.0004.000000T0000Z-111102T1600Z/
NORTH BAY MOUNTAINS-EAST BAY HILLS AND DIABLO RANGE-
900 AM PDT WED NOV 2 2011

...RED FLAG WARNING WILL EXPIRE AT 9 AM PDT THIS MORNING FOR
GUSTY WINDS AND LOW HUMIDITY FOR THE NORTH AND EAST BAY HILLS...

THE RED FLAG WARNING WILL EXPIRE AT 9 AM PDT THIS MORNING. 

GUSTY NORTHEAST WINDS WILL CONTINUE TO DECREASE THE REST OF THIS
MORNING. BY MIDDAY WINDS WILL SWITCH BACK TO ONSHORE AND HUMIDITY
VALUES WILL SLOWLY RECOVER THROUGH THIS AFTERNOON AND EVENING.
EVEN THOUGH THE PERIOD OF STRONGEST WINDS AND LOWEST HUMIDITY HAS
ENDED FIRE WEATHER INTERESTS SHOULD CONTINUE TO MONITOR THE
LATEST FORECASTS.

A STRONG COLD FRONT WILL MOVE THROUGH THE DISTRICT FROM NORTH TO
SOUTH THURSDAY AFTERNOON WITH SHOWERS...MUCH COLDER TEMPERATURES
AND GUSTY NORTHWEST WINDS.

$$

FOR MORE INFORMATION FROM NOAA/NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SANFRANCISCO (ALL LOWER CASE)

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 30, 8:16 PM PDTGale WarningMTR42 hr
Oct 31, 2:55 AM PDTDense Fog AdvisoryMTRMonterey, San Benito, Santa Cruz6 hr

Nearby

Red Flag Warnings in California, 2011Every red flag warning in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text.