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000
FXUS66 KMTR 230520
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1020 PM PDT FRI MAY 22 2015

.SYNOPSIS...LOW PRESSURE WILL GRADUALLY EXIT THE AREA TO THE EAST
OVER THE NEXT FEW DAYS...RESULTING IN A SLIGHT WARMING TREND THIS
WEEKEND. PATCHY DRIZZLE IS POSSIBLE IN COASTAL AREAS LATE TONIGHT
AND SUNDAY MORNING...ESPECIALLY SOUTH OF SAN FRANCISCO.
OTHERWISE...DRY WEATHER IS FORECAST THROUGH THE WEEKEND AND WELL
INTO NEXT WEEK.

&&

.DISCUSSION...AS OF 8:50 PM PDT FRIDAY...AN UPPER TROUGH MOVING TO
THE EAST OF CALIFORNIA PRODUCED CONSIDERABLE THUNDERSTORM
ACTIVITY OVER NEVADA AND EASTERN CALIFORNIA TODAY. THE LOW WAS TOO
FAR EAST TO GENERATE ANYTHING MORE THAN A FEW AFTERNOON CUMULUS
BUILD-UPS OVER OUR AREA.

THE LONGWAVE TROUGH POSITION WILL CONTINUE TO SHIFT EASTWARD OVER
THE NEXT FEW DAYS. HOWEVER...A SHORTWAVE TROUGH IS FORECAST TO
TRAVERSE CA FROM NW TO SE ON SATURDAY...TRIGGERING ANOTHER ROUND
OF CONVECTION OVER THE SIERRA NEVADA...AND PERHAPS AS CLOSE TO OUR
FORECAST AREA AS LAKE COUNTY. CONSIDERABLE LOW LEVEL MOISTURE
REMAINS ACROSS OUR AREA...AND AS THE SHORTWAVE APPROACHES FROM THE
NORTHWEST LATER TONIGHT...IT MAY ENHANCE ONSHORE FLOW ENOUGH TO
PRODUCE AREAS OF DRIZZLE IN COASTAL AREAS LATE TONIGHT AND
SATURDAY MORNING...PARTICULARLY IN COASTAL AREAS SOUTH OF THE
GOLDEN GATE.

THE GENERAL TREND OVER THE WEEKEND WILL BE FOR GRADUAL WARMING AND
MORE WIDESPREAD CLEARING AS THE LONGWAVE TROUGH CONTINUES TO MOVE
TO THE EAST AND AN UPPER RIDGE OVER THE EASTERN PAC EDGES CLOSER
TO THE WEST COAST. TEMPERATURES SHOULD CLIMB TO NEAR NORMAL BY SUNDAY.

THE WARMING TREND WILL PROBABLY STALL ON MONDAY AND TUESDAY AS AN
UPPER LOW SETTLES INTO THE PAC NW AND TEMPORARILY WEAKENS THE
RIDGE. WARMING IS THEN LIKELY TO RESUME DURING THE SECOND HALF OF
NEXT WEEK WHEN THE MODELS AGREE THAT THE UPPER RIDGE WILL RE-BUILD
ALONG THE WEST COAST. BUT TEMPERATURES ARE NOT EXPECTED TO WARM
MORE THAN A FEW DEGREES ABOVE NORMAL...AND RELATIVELY COOL
CONDITIONS WILL PERSIST NEAR THE COAST DUE TO CONTINUED ONSHORE
FLOW.

&&

.AVIATION...AS OF 10:07 PM PDT FRIDAY...NOT MUCH CHANGE FROM THE
PREVIOUS DISCUSSION. VFR/MVFR CIGS CONTINUE THIS EVENING WITH A
MIX OF CLOUD LAYERS AROUND THE REGION. LOW LEVEL MOISTURE WILL
LINGER INTO TONIGHT WITH A FEW PATCHES OF DRIZZLE BECOMING
POSSIBLE VERY LATE AT NIGHT. AN UPPER LEVEL HIGH OVER THE EPAC
WILL SLOWLY EDGE IN FROM THE WEST DURING THE PERIOD. SUBSIDENCE
ASSOCIATED WITH THE HIGH WILL RESULT IN A GRADUAL WARMING WITHIN
THE LOWER LEVELS CAUSING THE MARINE LAYER INVERSION TO BECOME RE-
ESTABLISHED OVER THE HOLIDAY WEEKEND. BY LATE SUNDAY NIGHT INTO
MONDAY 850 MB LEVEL TEMPS ARE PREDICTED TO REACH NEAR 15C.

VICINITY OF KSFO...MVFR CIGS. GUSTY WESTERLY WINDS ARE LIKELY TO
RETURN ON SATURDAY.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR/MVFR GRADUALLY DECREASING TO IFR
VERY LATE. PATCHY DRIZZLE POSSIBLE LATE. CLEARING RETURNS BY LATE
SAT MORNING.

&&

.MARINE...AS OF 10:02 PM PDT FRIDAY...HIGH PRESSURE IS STRENGTHENING
OVER THE COASTAL WATERS IN THE WAKE OF A SLUGGISH UPPER LOW. THIS
PATTERN IS LEADING TO GENERALLY DETERIORATING CONDITIONS FROM
INCREASING NORTHWEST WINDS AND BUILDING SEAS. UNFAVORABLE WINDS
AND SEAS ARE FORECAST PERSIST THROUGH THE WEEKEND BEFORE BEGINNING
TO TAPER OFF EARLY NEXT WEEK.

OVERALL FORECAST LOOKS GOOD. MINOR ADJUSTMENTS MADE TO THE FORECAST
WINDS FOR THE SAN FRANCISCO BAY WATERS NORTH OF THE BAY BRIDGE
SATURDAY AFTERNOON AND EVENING....DECIDED TO ADD A SMALL CRAFT
ADVISORY. BUMPED UP FORECAST WINDS A LITTLE FOR SUNDAY...BUT MAY
NOT BE ENOUGH. LATER SHIFTS MAY NEED TO CONSIDER ADDING A SMALL
CRAFT ADVISORY IN FOR LATER SUNDAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM
             SCA...PT ARENA TO PT REYES 0-10 NM
             SCA...PT REYES TO PIGEON PT 0-10 NM

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION: CANEPA
MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
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000
FXUS66 KMTR 230520
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1020 PM PDT FRI MAY 22 2015

.SYNOPSIS...LOW PRESSURE WILL GRADUALLY EXIT THE AREA TO THE EAST
OVER THE NEXT FEW DAYS...RESULTING IN A SLIGHT WARMING TREND THIS
WEEKEND. PATCHY DRIZZLE IS POSSIBLE IN COASTAL AREAS LATE TONIGHT
AND SUNDAY MORNING...ESPECIALLY SOUTH OF SAN FRANCISCO.
OTHERWISE...DRY WEATHER IS FORECAST THROUGH THE WEEKEND AND WELL
INTO NEXT WEEK.

&&

.DISCUSSION...AS OF 8:50 PM PDT FRIDAY...AN UPPER TROUGH MOVING TO
THE EAST OF CALIFORNIA PRODUCED CONSIDERABLE THUNDERSTORM
ACTIVITY OVER NEVADA AND EASTERN CALIFORNIA TODAY. THE LOW WAS TOO
FAR EAST TO GENERATE ANYTHING MORE THAN A FEW AFTERNOON CUMULUS
BUILD-UPS OVER OUR AREA.

THE LONGWAVE TROUGH POSITION WILL CONTINUE TO SHIFT EASTWARD OVER
THE NEXT FEW DAYS. HOWEVER...A SHORTWAVE TROUGH IS FORECAST TO
TRAVERSE CA FROM NW TO SE ON SATURDAY...TRIGGERING ANOTHER ROUND
OF CONVECTION OVER THE SIERRA NEVADA...AND PERHAPS AS CLOSE TO OUR
FORECAST AREA AS LAKE COUNTY. CONSIDERABLE LOW LEVEL MOISTURE
REMAINS ACROSS OUR AREA...AND AS THE SHORTWAVE APPROACHES FROM THE
NORTHWEST LATER TONIGHT...IT MAY ENHANCE ONSHORE FLOW ENOUGH TO
PRODUCE AREAS OF DRIZZLE IN COASTAL AREAS LATE TONIGHT AND
SATURDAY MORNING...PARTICULARLY IN COASTAL AREAS SOUTH OF THE
GOLDEN GATE.

THE GENERAL TREND OVER THE WEEKEND WILL BE FOR GRADUAL WARMING AND
MORE WIDESPREAD CLEARING AS THE LONGWAVE TROUGH CONTINUES TO MOVE
TO THE EAST AND AN UPPER RIDGE OVER THE EASTERN PAC EDGES CLOSER
TO THE WEST COAST. TEMPERATURES SHOULD CLIMB TO NEAR NORMAL BY SUNDAY.

THE WARMING TREND WILL PROBABLY STALL ON MONDAY AND TUESDAY AS AN
UPPER LOW SETTLES INTO THE PAC NW AND TEMPORARILY WEAKENS THE
RIDGE. WARMING IS THEN LIKELY TO RESUME DURING THE SECOND HALF OF
NEXT WEEK WHEN THE MODELS AGREE THAT THE UPPER RIDGE WILL RE-BUILD
ALONG THE WEST COAST. BUT TEMPERATURES ARE NOT EXPECTED TO WARM
MORE THAN A FEW DEGREES ABOVE NORMAL...AND RELATIVELY COOL
CONDITIONS WILL PERSIST NEAR THE COAST DUE TO CONTINUED ONSHORE
FLOW.

&&

.AVIATION...AS OF 10:07 PM PDT FRIDAY...NOT MUCH CHANGE FROM THE
PREVIOUS DISCUSSION. VFR/MVFR CIGS CONTINUE THIS EVENING WITH A
MIX OF CLOUD LAYERS AROUND THE REGION. LOW LEVEL MOISTURE WILL
LINGER INTO TONIGHT WITH A FEW PATCHES OF DRIZZLE BECOMING
POSSIBLE VERY LATE AT NIGHT. AN UPPER LEVEL HIGH OVER THE EPAC
WILL SLOWLY EDGE IN FROM THE WEST DURING THE PERIOD. SUBSIDENCE
ASSOCIATED WITH THE HIGH WILL RESULT IN A GRADUAL WARMING WITHIN
THE LOWER LEVELS CAUSING THE MARINE LAYER INVERSION TO BECOME RE-
ESTABLISHED OVER THE HOLIDAY WEEKEND. BY LATE SUNDAY NIGHT INTO
MONDAY 850 MB LEVEL TEMPS ARE PREDICTED TO REACH NEAR 15C.

VICINITY OF KSFO...MVFR CIGS. GUSTY WESTERLY WINDS ARE LIKELY TO
RETURN ON SATURDAY.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR/MVFR GRADUALLY DECREASING TO IFR
VERY LATE. PATCHY DRIZZLE POSSIBLE LATE. CLEARING RETURNS BY LATE
SAT MORNING.

&&

.MARINE...AS OF 10:02 PM PDT FRIDAY...HIGH PRESSURE IS STRENGTHENING
OVER THE COASTAL WATERS IN THE WAKE OF A SLUGGISH UPPER LOW. THIS
PATTERN IS LEADING TO GENERALLY DETERIORATING CONDITIONS FROM
INCREASING NORTHWEST WINDS AND BUILDING SEAS. UNFAVORABLE WINDS
AND SEAS ARE FORECAST PERSIST THROUGH THE WEEKEND BEFORE BEGINNING
TO TAPER OFF EARLY NEXT WEEK.

OVERALL FORECAST LOOKS GOOD. MINOR ADJUSTMENTS MADE TO THE FORECAST
WINDS FOR THE SAN FRANCISCO BAY WATERS NORTH OF THE BAY BRIDGE
SATURDAY AFTERNOON AND EVENING....DECIDED TO ADD A SMALL CRAFT
ADVISORY. BUMPED UP FORECAST WINDS A LITTLE FOR SUNDAY...BUT MAY
NOT BE ENOUGH. LATER SHIFTS MAY NEED TO CONSIDER ADDING A SMALL
CRAFT ADVISORY IN FOR LATER SUNDAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM
             SCA...PT ARENA TO PT REYES 0-10 NM
             SCA...PT REYES TO PIGEON PT 0-10 NM

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION: CANEPA
MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 230520
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1020 PM PDT FRI MAY 22 2015

.SYNOPSIS...LOW PRESSURE WILL GRADUALLY EXIT THE AREA TO THE EAST
OVER THE NEXT FEW DAYS...RESULTING IN A SLIGHT WARMING TREND THIS
WEEKEND. PATCHY DRIZZLE IS POSSIBLE IN COASTAL AREAS LATE TONIGHT
AND SUNDAY MORNING...ESPECIALLY SOUTH OF SAN FRANCISCO.
OTHERWISE...DRY WEATHER IS FORECAST THROUGH THE WEEKEND AND WELL
INTO NEXT WEEK.

&&

.DISCUSSION...AS OF 8:50 PM PDT FRIDAY...AN UPPER TROUGH MOVING TO
THE EAST OF CALIFORNIA PRODUCED CONSIDERABLE THUNDERSTORM
ACTIVITY OVER NEVADA AND EASTERN CALIFORNIA TODAY. THE LOW WAS TOO
FAR EAST TO GENERATE ANYTHING MORE THAN A FEW AFTERNOON CUMULUS
BUILD-UPS OVER OUR AREA.

THE LONGWAVE TROUGH POSITION WILL CONTINUE TO SHIFT EASTWARD OVER
THE NEXT FEW DAYS. HOWEVER...A SHORTWAVE TROUGH IS FORECAST TO
TRAVERSE CA FROM NW TO SE ON SATURDAY...TRIGGERING ANOTHER ROUND
OF CONVECTION OVER THE SIERRA NEVADA...AND PERHAPS AS CLOSE TO OUR
FORECAST AREA AS LAKE COUNTY. CONSIDERABLE LOW LEVEL MOISTURE
REMAINS ACROSS OUR AREA...AND AS THE SHORTWAVE APPROACHES FROM THE
NORTHWEST LATER TONIGHT...IT MAY ENHANCE ONSHORE FLOW ENOUGH TO
PRODUCE AREAS OF DRIZZLE IN COASTAL AREAS LATE TONIGHT AND
SATURDAY MORNING...PARTICULARLY IN COASTAL AREAS SOUTH OF THE
GOLDEN GATE.

THE GENERAL TREND OVER THE WEEKEND WILL BE FOR GRADUAL WARMING AND
MORE WIDESPREAD CLEARING AS THE LONGWAVE TROUGH CONTINUES TO MOVE
TO THE EAST AND AN UPPER RIDGE OVER THE EASTERN PAC EDGES CLOSER
TO THE WEST COAST. TEMPERATURES SHOULD CLIMB TO NEAR NORMAL BY SUNDAY.

THE WARMING TREND WILL PROBABLY STALL ON MONDAY AND TUESDAY AS AN
UPPER LOW SETTLES INTO THE PAC NW AND TEMPORARILY WEAKENS THE
RIDGE. WARMING IS THEN LIKELY TO RESUME DURING THE SECOND HALF OF
NEXT WEEK WHEN THE MODELS AGREE THAT THE UPPER RIDGE WILL RE-BUILD
ALONG THE WEST COAST. BUT TEMPERATURES ARE NOT EXPECTED TO WARM
MORE THAN A FEW DEGREES ABOVE NORMAL...AND RELATIVELY COOL
CONDITIONS WILL PERSIST NEAR THE COAST DUE TO CONTINUED ONSHORE
FLOW.

&&

.AVIATION...AS OF 10:07 PM PDT FRIDAY...NOT MUCH CHANGE FROM THE
PREVIOUS DISCUSSION. VFR/MVFR CIGS CONTINUE THIS EVENING WITH A
MIX OF CLOUD LAYERS AROUND THE REGION. LOW LEVEL MOISTURE WILL
LINGER INTO TONIGHT WITH A FEW PATCHES OF DRIZZLE BECOMING
POSSIBLE VERY LATE AT NIGHT. AN UPPER LEVEL HIGH OVER THE EPAC
WILL SLOWLY EDGE IN FROM THE WEST DURING THE PERIOD. SUBSIDENCE
ASSOCIATED WITH THE HIGH WILL RESULT IN A GRADUAL WARMING WITHIN
THE LOWER LEVELS CAUSING THE MARINE LAYER INVERSION TO BECOME RE-
ESTABLISHED OVER THE HOLIDAY WEEKEND. BY LATE SUNDAY NIGHT INTO
MONDAY 850 MB LEVEL TEMPS ARE PREDICTED TO REACH NEAR 15C.

VICINITY OF KSFO...MVFR CIGS. GUSTY WESTERLY WINDS ARE LIKELY TO
RETURN ON SATURDAY.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR/MVFR GRADUALLY DECREASING TO IFR
VERY LATE. PATCHY DRIZZLE POSSIBLE LATE. CLEARING RETURNS BY LATE
SAT MORNING.

&&

.MARINE...AS OF 10:02 PM PDT FRIDAY...HIGH PRESSURE IS STRENGTHENING
OVER THE COASTAL WATERS IN THE WAKE OF A SLUGGISH UPPER LOW. THIS
PATTERN IS LEADING TO GENERALLY DETERIORATING CONDITIONS FROM
INCREASING NORTHWEST WINDS AND BUILDING SEAS. UNFAVORABLE WINDS
AND SEAS ARE FORECAST PERSIST THROUGH THE WEEKEND BEFORE BEGINNING
TO TAPER OFF EARLY NEXT WEEK.

OVERALL FORECAST LOOKS GOOD. MINOR ADJUSTMENTS MADE TO THE FORECAST
WINDS FOR THE SAN FRANCISCO BAY WATERS NORTH OF THE BAY BRIDGE
SATURDAY AFTERNOON AND EVENING....DECIDED TO ADD A SMALL CRAFT
ADVISORY. BUMPED UP FORECAST WINDS A LITTLE FOR SUNDAY...BUT MAY
NOT BE ENOUGH. LATER SHIFTS MAY NEED TO CONSIDER ADDING A SMALL
CRAFT ADVISORY IN FOR LATER SUNDAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM
             SCA...PT ARENA TO PT REYES 0-10 NM
             SCA...PT REYES TO PIGEON PT 0-10 NM

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION: CANEPA
MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 230520
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1020 PM PDT FRI MAY 22 2015

.SYNOPSIS...LOW PRESSURE WILL GRADUALLY EXIT THE AREA TO THE EAST
OVER THE NEXT FEW DAYS...RESULTING IN A SLIGHT WARMING TREND THIS
WEEKEND. PATCHY DRIZZLE IS POSSIBLE IN COASTAL AREAS LATE TONIGHT
AND SUNDAY MORNING...ESPECIALLY SOUTH OF SAN FRANCISCO.
OTHERWISE...DRY WEATHER IS FORECAST THROUGH THE WEEKEND AND WELL
INTO NEXT WEEK.

&&

.DISCUSSION...AS OF 8:50 PM PDT FRIDAY...AN UPPER TROUGH MOVING TO
THE EAST OF CALIFORNIA PRODUCED CONSIDERABLE THUNDERSTORM
ACTIVITY OVER NEVADA AND EASTERN CALIFORNIA TODAY. THE LOW WAS TOO
FAR EAST TO GENERATE ANYTHING MORE THAN A FEW AFTERNOON CUMULUS
BUILD-UPS OVER OUR AREA.

THE LONGWAVE TROUGH POSITION WILL CONTINUE TO SHIFT EASTWARD OVER
THE NEXT FEW DAYS. HOWEVER...A SHORTWAVE TROUGH IS FORECAST TO
TRAVERSE CA FROM NW TO SE ON SATURDAY...TRIGGERING ANOTHER ROUND
OF CONVECTION OVER THE SIERRA NEVADA...AND PERHAPS AS CLOSE TO OUR
FORECAST AREA AS LAKE COUNTY. CONSIDERABLE LOW LEVEL MOISTURE
REMAINS ACROSS OUR AREA...AND AS THE SHORTWAVE APPROACHES FROM THE
NORTHWEST LATER TONIGHT...IT MAY ENHANCE ONSHORE FLOW ENOUGH TO
PRODUCE AREAS OF DRIZZLE IN COASTAL AREAS LATE TONIGHT AND
SATURDAY MORNING...PARTICULARLY IN COASTAL AREAS SOUTH OF THE
GOLDEN GATE.

THE GENERAL TREND OVER THE WEEKEND WILL BE FOR GRADUAL WARMING AND
MORE WIDESPREAD CLEARING AS THE LONGWAVE TROUGH CONTINUES TO MOVE
TO THE EAST AND AN UPPER RIDGE OVER THE EASTERN PAC EDGES CLOSER
TO THE WEST COAST. TEMPERATURES SHOULD CLIMB TO NEAR NORMAL BY SUNDAY.

THE WARMING TREND WILL PROBABLY STALL ON MONDAY AND TUESDAY AS AN
UPPER LOW SETTLES INTO THE PAC NW AND TEMPORARILY WEAKENS THE
RIDGE. WARMING IS THEN LIKELY TO RESUME DURING THE SECOND HALF OF
NEXT WEEK WHEN THE MODELS AGREE THAT THE UPPER RIDGE WILL RE-BUILD
ALONG THE WEST COAST. BUT TEMPERATURES ARE NOT EXPECTED TO WARM
MORE THAN A FEW DEGREES ABOVE NORMAL...AND RELATIVELY COOL
CONDITIONS WILL PERSIST NEAR THE COAST DUE TO CONTINUED ONSHORE
FLOW.

&&

.AVIATION...AS OF 10:07 PM PDT FRIDAY...NOT MUCH CHANGE FROM THE
PREVIOUS DISCUSSION. VFR/MVFR CIGS CONTINUE THIS EVENING WITH A
MIX OF CLOUD LAYERS AROUND THE REGION. LOW LEVEL MOISTURE WILL
LINGER INTO TONIGHT WITH A FEW PATCHES OF DRIZZLE BECOMING
POSSIBLE VERY LATE AT NIGHT. AN UPPER LEVEL HIGH OVER THE EPAC
WILL SLOWLY EDGE IN FROM THE WEST DURING THE PERIOD. SUBSIDENCE
ASSOCIATED WITH THE HIGH WILL RESULT IN A GRADUAL WARMING WITHIN
THE LOWER LEVELS CAUSING THE MARINE LAYER INVERSION TO BECOME RE-
ESTABLISHED OVER THE HOLIDAY WEEKEND. BY LATE SUNDAY NIGHT INTO
MONDAY 850 MB LEVEL TEMPS ARE PREDICTED TO REACH NEAR 15C.

VICINITY OF KSFO...MVFR CIGS. GUSTY WESTERLY WINDS ARE LIKELY TO
RETURN ON SATURDAY.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR/MVFR GRADUALLY DECREASING TO IFR
VERY LATE. PATCHY DRIZZLE POSSIBLE LATE. CLEARING RETURNS BY LATE
SAT MORNING.

&&

.MARINE...AS OF 10:02 PM PDT FRIDAY...HIGH PRESSURE IS STRENGTHENING
OVER THE COASTAL WATERS IN THE WAKE OF A SLUGGISH UPPER LOW. THIS
PATTERN IS LEADING TO GENERALLY DETERIORATING CONDITIONS FROM
INCREASING NORTHWEST WINDS AND BUILDING SEAS. UNFAVORABLE WINDS
AND SEAS ARE FORECAST PERSIST THROUGH THE WEEKEND BEFORE BEGINNING
TO TAPER OFF EARLY NEXT WEEK.

OVERALL FORECAST LOOKS GOOD. MINOR ADJUSTMENTS MADE TO THE FORECAST
WINDS FOR THE SAN FRANCISCO BAY WATERS NORTH OF THE BAY BRIDGE
SATURDAY AFTERNOON AND EVENING....DECIDED TO ADD A SMALL CRAFT
ADVISORY. BUMPED UP FORECAST WINDS A LITTLE FOR SUNDAY...BUT MAY
NOT BE ENOUGH. LATER SHIFTS MAY NEED TO CONSIDER ADDING A SMALL
CRAFT ADVISORY IN FOR LATER SUNDAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM
             SCA...PT ARENA TO PT REYES 0-10 NM
             SCA...PT REYES TO PIGEON PT 0-10 NM

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION: CANEPA
MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 230354
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
854 PM PDT FRI MAY 22 2015

.SYNOPSIS...LOW PRESSURE WILL GRADUALLY EXIT THE AREA TO THE EAST
OVER THE NEXT FEW DAYS...RESULTING IN A SLIGHT WARMING TREND THIS
WEEKEND. PATCHY DRIZZLE IS POSSIBLE IN COASTAL AREAS LATE TONIGHT
AND SUNDAY MORNING...ESPECIALLY SOUTH OF SAN FRANCISCO.
OTHERWISE...DRY WEATHER IS FORECAST THROUGH THE WEEKEND AND WELL
INTO NEXT WEEK.

&&

.DISCUSSION...AS OF 8:50 PM PDT FRIDAY...AN UPPER TROUGH MOVING TO
THE EAST OF CALIFORNIA PRODUCED CONSIDERABLE THUNDERSTORM
ACTIVITY OVER NEVADA AND EASTERN CALIFORNIA TODAY. THE LOW WAS TOO
FAR EAST TO GENERATE ANYTHING MORE THAN A FEW AFTERNOON CUMULUS
BUILD-UPS OVER OUR AREA.

THE LONGWAVE TROUGH POSITION WILL CONTINUE TO SHIFT EASTWARD OVER
THE NEXT FEW DAYS. HOWEVER...A SHORTWAVE TROUGH IS FORECAST TO
TRAVERSE CA FROM NW TO SE ON SATURDAY...TRIGGERING ANOTHER ROUND
OF CONVECTION OVER THE SIERRA NEVADA...AND PERHAPS AS CLOSE TO OUR
FORECAST AREA AS LAKE COUNTY. CONSIDERABLE LOW LEVEL MOISTURE
REMAINS ACROSS OUR AREA...AND AS THE SHORTWAVE APPROACHES FROM THE
NORTHWEST LATER TONIGHT...IT MAY ENHANCE ONSHORE FLOW ENOUGH TO
PRODUCE AREAS OF DRIZZLE IN COASTAL AREAS LATE TONIGHT AND
SATURDAY MORNING...PARTICULARLY IN COASTAL AREAS SOUTH OF THE
GOLDEN GATE.

THE GENERAL TREND OVER THE WEEKEND WILL BE FOR GRADUAL WARMING AND
MORE WIDESPREAD CLEARING AS THE LONGWAVE TROUGH CONTINUES TO MOVE
TO THE EAST AND AN UPPER RIDGE OVER THE EASTERN PAC EDGES CLOSER
TO THE WEST COAST. TEMPERATURES SHOULD CLIMB TO NEAR NORMAL BY SUNDAY.

THE WARMING TREND WILL PROBABLY STALL ON MONDAY AND TUESDAY AS AN
UPPER LOW SETTLES INTO THE PAC NW AND TEMPORARILY WEAKENS THE
RIDGE. WARMING IS THEN LIKELY TO RESUME DURING THE SECOND HALF OF
NEXT WEEK WHEN THE MODELS AGREE THAT THE UPPER RIDGE WILL RE-BUILD
ALONG THE WEST COAST. BUT TEMPERATURES ARE NOT EXPECTED TO WARM
MORE THAN A FEW DEGREES ABOVE NORMAL...AND RELATIVELY COOL
CONDITIONS WILL PERSIST NEAR THE COAST DUE TO CONTINUED ONSHORE
FLOW.

&&

.AVIATION...AS OF 5:07 PM PDT FRIDAY...THERE`S A MIX OF CLEAR SKIES
AND AREAS OF CLOUDS AROUND THE REGION THIS AFTERNOON. GENERALLY
CONDITIONS ARE VFR/MVFR. LOW LEVEL MOISTURE WILL LINGER INTO
TONIGHT WITH A FEW PATCHES OF DRIZZLE BECOMING POSSIBLE VERY LATE
AT NIGHT. AN UPPER LEVEL HIGH OVER THE EPAC WILL SLOWLY EDGE IN
FROM THE WEST DURING THE PERIOD. THERE`S NO SIGN OF A MARINE
INVERSION YET PER CHECK OF THE FORT ORD AND BODEGA BAY PROFILERS.
HOWEVER SUBSIDENCE ASSOCIATED WITH THE HIGH WILL RESULT IN A
GRADUAL WARMING WITHIN THE LOWER LEVELS CAUSING THE MARINE LAYER
INVERSION TO BECOME RE-ESTABLISHED OVER THE HOLIDAY WEEKEND. BY
LATE SUNDAY NIGHT INTO MONDAY 850 MB LEVEL TEMPS ARE PREDICTED TO
REACH NEAR 15C.

VICINITY OF KSFO...MVFR CIGS WITH WESTERLY WINDS GUSTY MOSTLY HOLDING
BELOW 20 KNOTS THROUGH THE EVENING. LIGHTER WINDS EXPECTED
OVERNIGHT...BUT A RETURN TO GUSTY WEST WINDS IS VERY LIKELY SAT
AFTERNOON WITH GUSTS UP OVER 20 KNOTS.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR/MVFR GRADUALLY DECREASING TO IFR
VERY LATE. PATCHY DRIZZLE POSSIBLE LATE. CLEARING RETURNS BY LATE
SAT MORNING.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WATERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM FROM 8 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 8 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION: CANEPA
MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 230354
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
854 PM PDT FRI MAY 22 2015

.SYNOPSIS...LOW PRESSURE WILL GRADUALLY EXIT THE AREA TO THE EAST
OVER THE NEXT FEW DAYS...RESULTING IN A SLIGHT WARMING TREND THIS
WEEKEND. PATCHY DRIZZLE IS POSSIBLE IN COASTAL AREAS LATE TONIGHT
AND SUNDAY MORNING...ESPECIALLY SOUTH OF SAN FRANCISCO.
OTHERWISE...DRY WEATHER IS FORECAST THROUGH THE WEEKEND AND WELL
INTO NEXT WEEK.

&&

.DISCUSSION...AS OF 8:50 PM PDT FRIDAY...AN UPPER TROUGH MOVING TO
THE EAST OF CALIFORNIA PRODUCED CONSIDERABLE THUNDERSTORM
ACTIVITY OVER NEVADA AND EASTERN CALIFORNIA TODAY. THE LOW WAS TOO
FAR EAST TO GENERATE ANYTHING MORE THAN A FEW AFTERNOON CUMULUS
BUILD-UPS OVER OUR AREA.

THE LONGWAVE TROUGH POSITION WILL CONTINUE TO SHIFT EASTWARD OVER
THE NEXT FEW DAYS. HOWEVER...A SHORTWAVE TROUGH IS FORECAST TO
TRAVERSE CA FROM NW TO SE ON SATURDAY...TRIGGERING ANOTHER ROUND
OF CONVECTION OVER THE SIERRA NEVADA...AND PERHAPS AS CLOSE TO OUR
FORECAST AREA AS LAKE COUNTY. CONSIDERABLE LOW LEVEL MOISTURE
REMAINS ACROSS OUR AREA...AND AS THE SHORTWAVE APPROACHES FROM THE
NORTHWEST LATER TONIGHT...IT MAY ENHANCE ONSHORE FLOW ENOUGH TO
PRODUCE AREAS OF DRIZZLE IN COASTAL AREAS LATE TONIGHT AND
SATURDAY MORNING...PARTICULARLY IN COASTAL AREAS SOUTH OF THE
GOLDEN GATE.

THE GENERAL TREND OVER THE WEEKEND WILL BE FOR GRADUAL WARMING AND
MORE WIDESPREAD CLEARING AS THE LONGWAVE TROUGH CONTINUES TO MOVE
TO THE EAST AND AN UPPER RIDGE OVER THE EASTERN PAC EDGES CLOSER
TO THE WEST COAST. TEMPERATURES SHOULD CLIMB TO NEAR NORMAL BY SUNDAY.

THE WARMING TREND WILL PROBABLY STALL ON MONDAY AND TUESDAY AS AN
UPPER LOW SETTLES INTO THE PAC NW AND TEMPORARILY WEAKENS THE
RIDGE. WARMING IS THEN LIKELY TO RESUME DURING THE SECOND HALF OF
NEXT WEEK WHEN THE MODELS AGREE THAT THE UPPER RIDGE WILL RE-BUILD
ALONG THE WEST COAST. BUT TEMPERATURES ARE NOT EXPECTED TO WARM
MORE THAN A FEW DEGREES ABOVE NORMAL...AND RELATIVELY COOL
CONDITIONS WILL PERSIST NEAR THE COAST DUE TO CONTINUED ONSHORE
FLOW.

&&

.AVIATION...AS OF 5:07 PM PDT FRIDAY...THERE`S A MIX OF CLEAR SKIES
AND AREAS OF CLOUDS AROUND THE REGION THIS AFTERNOON. GENERALLY
CONDITIONS ARE VFR/MVFR. LOW LEVEL MOISTURE WILL LINGER INTO
TONIGHT WITH A FEW PATCHES OF DRIZZLE BECOMING POSSIBLE VERY LATE
AT NIGHT. AN UPPER LEVEL HIGH OVER THE EPAC WILL SLOWLY EDGE IN
FROM THE WEST DURING THE PERIOD. THERE`S NO SIGN OF A MARINE
INVERSION YET PER CHECK OF THE FORT ORD AND BODEGA BAY PROFILERS.
HOWEVER SUBSIDENCE ASSOCIATED WITH THE HIGH WILL RESULT IN A
GRADUAL WARMING WITHIN THE LOWER LEVELS CAUSING THE MARINE LAYER
INVERSION TO BECOME RE-ESTABLISHED OVER THE HOLIDAY WEEKEND. BY
LATE SUNDAY NIGHT INTO MONDAY 850 MB LEVEL TEMPS ARE PREDICTED TO
REACH NEAR 15C.

VICINITY OF KSFO...MVFR CIGS WITH WESTERLY WINDS GUSTY MOSTLY HOLDING
BELOW 20 KNOTS THROUGH THE EVENING. LIGHTER WINDS EXPECTED
OVERNIGHT...BUT A RETURN TO GUSTY WEST WINDS IS VERY LIKELY SAT
AFTERNOON WITH GUSTS UP OVER 20 KNOTS.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR/MVFR GRADUALLY DECREASING TO IFR
VERY LATE. PATCHY DRIZZLE POSSIBLE LATE. CLEARING RETURNS BY LATE
SAT MORNING.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WATERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM FROM 8 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 8 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION: CANEPA
MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 230009
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
509 PM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CONTINUE TO EXIT THE REGION
AS HIGH PRESSURE BUILDS. THE BUILDING HIGH PRESSURE WILL RESULT
DRIER CONDITIONS AND A SLIGHT WARMING TREND OF THROUGH EARLY NEXT
WEEK.

&&

.DISCUSSION...AS OF 2:50 PM PDT FRIDAY...CHANCE OF PRECIPITATION
CONTINUES TO DIMINISH AS A STORM SYSTEM EXITS AND HIGH PRESSURE
BUILDS. DRIER WEATHER EXPECTED WITH A SLIGHT WARMING TREND THROUGH
EARLY NEXT WEEK.

LATEST SURFACE OBSERVATIONS AND KMUX RADAR IMAGERY BOTH INDICATE
EARLIER SHOWER ACTIVITY HAS DIMINISHED ACROSS THE BAY AREA.
THEREFORE...REMOVED ANY MENTION OF SHOWERS THIS AFTERNOON AND EARLY
THIS EVENING. HOWEVER...THE VISIBLE SATELLITE DOES INDICATE
LINGERING MOISTURE...BUT MAINLY IN THE FORM OF CUMULUS
CLOUDS...ESPECIALLY OVER THE HILLS.

EXPECT THE CUMULUS CLOUDS TO GRADUALLY DISSIPATE AFTER SUNSET AS
DAYTIME HEATING ENDS. HIGH PRESSURE CURRENTLY OVER THE EPAC WILL
SLOWLY BUILDING THROUGH THE WEEKEND WITH A MORE SUMMER LIKE
PATTERN. NIGHT AND MORNING LOW CLOUDS WILL BE COMMON WITH A MORE
DEFINED MARINE LAYER. WILL KEEP THE MENTION OF DRIZZLE EARLY
SATURDAY DUE TO THE AMPLE LOW LEVEL MOISTURE. INTERESTING TO NOTE
AS WELL..THE NAM/GFS BOTH SHOW WIDESPREAD VERY LIGHT PRECIP EARLY
SATURDAY. LOOKS VERY SIMILAR TO WHAT WAS OBSERVED ON TUESDAY WITH
MANY LOCATIONS PICKING UP A HUNDREDTH OR TWO. CONF IS NOT HIGH
ENOUGH TO PUT IN WIDESPREAD DRIZZLE...BETTER SHOT ALONG THE COAST.
DESPITE THE FORECAST WARMING TREND...MUCH OF THE BAY AREA WILL
STILL BE A FEW DEGREES BELOW NORMAL. HIGHS WILL GENERALLY BE 60S
ALONG THE COAST AND 60S/70S INLAND THROUGH.

BEYOND THE HOLIDAY WEEKEND...850MB TEMPS AND 500MB HEIGHTS
CONTINUE TO RISE THROUGH MUCH OF NEXT. AS A RESULT...THE WARMING
TREND WILL LIKELY CONTINUE WITH NEAR NORMAL TEMPERATURES(80S WELL
INLAND). NIGHT AND MORNING CLOUDS WILL REMAIN WITH ONSHORE FLOW.
DRY WEATHER CONTINUES.

&&

.AVIATION...AS OF 5:07 PM PDT FRIDAY...THERE`S A MIX OF CLEAR SKIES
AND AREAS OF CLOUDS AROUND THE REGION THIS AFTERNOON. GENERALLY
CONDITIONS ARE VFR/MVFR. LOW LEVEL MOISTURE WILL LINGER INTO
TONIGHT WITH A FEW PATCHES OF DRIZZLE BECOMING POSSIBLE VERY LATE
AT NIGHT. AN UPPER LEVEL HIGH OVER THE EPAC WILL SLOWLY EDGE IN
FROM THE WEST DURING THE PERIOD. THERE`S NO SIGN OF A MARINE
INVERSION YET PER CHECK OF THE FORT ORD AND BODEGA BAY PROFILERS.
HOWEVER SUBSIDENCE ASSOCIATED WITH THE HIGH WILL RESULT IN A
GRADUAL WARMING WITHIN THE LOWER LEVELS CAUSING THE MARINE LAYER
INVERSION TO BECOME RE-ESTABLISHED OVER THE HOLIDAY WEEKEND. BY
LATE SUNDAY NIGHT INTO MONDAY 850 MB LEVEL TEMPS ARE PREDICTED TO
REACH NEAR 15C.

VICINITY OF KSFO...MVFR CIGS WITH WESTERLY WINDS GUSTY MOSTLY HOLDING
BELOW 20 KNOTS THROUGH THE EVENING. LIGHTER WINDS EXPECTED
OVERNIGHT...BUT A RETURN TO GUSTY WEST WINDS IS VERY LIKELY SAT
AFTERNOON WITH GUSTS UP OVER 20 KNOTS.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR/MVFR GRADUALLY DECREASING TO IFR
VERY LATE. PATCHY DRIZZLE POSSIBLE LATE. CLEARING RETURNS BY LATE
SAT MORNING.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WATERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM FROM 8 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 8 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION: CANEPA
MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 230009
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
509 PM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CONTINUE TO EXIT THE REGION
AS HIGH PRESSURE BUILDS. THE BUILDING HIGH PRESSURE WILL RESULT
DRIER CONDITIONS AND A SLIGHT WARMING TREND OF THROUGH EARLY NEXT
WEEK.

&&

.DISCUSSION...AS OF 2:50 PM PDT FRIDAY...CHANCE OF PRECIPITATION
CONTINUES TO DIMINISH AS A STORM SYSTEM EXITS AND HIGH PRESSURE
BUILDS. DRIER WEATHER EXPECTED WITH A SLIGHT WARMING TREND THROUGH
EARLY NEXT WEEK.

LATEST SURFACE OBSERVATIONS AND KMUX RADAR IMAGERY BOTH INDICATE
EARLIER SHOWER ACTIVITY HAS DIMINISHED ACROSS THE BAY AREA.
THEREFORE...REMOVED ANY MENTION OF SHOWERS THIS AFTERNOON AND EARLY
THIS EVENING. HOWEVER...THE VISIBLE SATELLITE DOES INDICATE
LINGERING MOISTURE...BUT MAINLY IN THE FORM OF CUMULUS
CLOUDS...ESPECIALLY OVER THE HILLS.

EXPECT THE CUMULUS CLOUDS TO GRADUALLY DISSIPATE AFTER SUNSET AS
DAYTIME HEATING ENDS. HIGH PRESSURE CURRENTLY OVER THE EPAC WILL
SLOWLY BUILDING THROUGH THE WEEKEND WITH A MORE SUMMER LIKE
PATTERN. NIGHT AND MORNING LOW CLOUDS WILL BE COMMON WITH A MORE
DEFINED MARINE LAYER. WILL KEEP THE MENTION OF DRIZZLE EARLY
SATURDAY DUE TO THE AMPLE LOW LEVEL MOISTURE. INTERESTING TO NOTE
AS WELL..THE NAM/GFS BOTH SHOW WIDESPREAD VERY LIGHT PRECIP EARLY
SATURDAY. LOOKS VERY SIMILAR TO WHAT WAS OBSERVED ON TUESDAY WITH
MANY LOCATIONS PICKING UP A HUNDREDTH OR TWO. CONF IS NOT HIGH
ENOUGH TO PUT IN WIDESPREAD DRIZZLE...BETTER SHOT ALONG THE COAST.
DESPITE THE FORECAST WARMING TREND...MUCH OF THE BAY AREA WILL
STILL BE A FEW DEGREES BELOW NORMAL. HIGHS WILL GENERALLY BE 60S
ALONG THE COAST AND 60S/70S INLAND THROUGH.

BEYOND THE HOLIDAY WEEKEND...850MB TEMPS AND 500MB HEIGHTS
CONTINUE TO RISE THROUGH MUCH OF NEXT. AS A RESULT...THE WARMING
TREND WILL LIKELY CONTINUE WITH NEAR NORMAL TEMPERATURES(80S WELL
INLAND). NIGHT AND MORNING CLOUDS WILL REMAIN WITH ONSHORE FLOW.
DRY WEATHER CONTINUES.

&&

.AVIATION...AS OF 5:07 PM PDT FRIDAY...THERE`S A MIX OF CLEAR SKIES
AND AREAS OF CLOUDS AROUND THE REGION THIS AFTERNOON. GENERALLY
CONDITIONS ARE VFR/MVFR. LOW LEVEL MOISTURE WILL LINGER INTO
TONIGHT WITH A FEW PATCHES OF DRIZZLE BECOMING POSSIBLE VERY LATE
AT NIGHT. AN UPPER LEVEL HIGH OVER THE EPAC WILL SLOWLY EDGE IN
FROM THE WEST DURING THE PERIOD. THERE`S NO SIGN OF A MARINE
INVERSION YET PER CHECK OF THE FORT ORD AND BODEGA BAY PROFILERS.
HOWEVER SUBSIDENCE ASSOCIATED WITH THE HIGH WILL RESULT IN A
GRADUAL WARMING WITHIN THE LOWER LEVELS CAUSING THE MARINE LAYER
INVERSION TO BECOME RE-ESTABLISHED OVER THE HOLIDAY WEEKEND. BY
LATE SUNDAY NIGHT INTO MONDAY 850 MB LEVEL TEMPS ARE PREDICTED TO
REACH NEAR 15C.

VICINITY OF KSFO...MVFR CIGS WITH WESTERLY WINDS GUSTY MOSTLY HOLDING
BELOW 20 KNOTS THROUGH THE EVENING. LIGHTER WINDS EXPECTED
OVERNIGHT...BUT A RETURN TO GUSTY WEST WINDS IS VERY LIKELY SAT
AFTERNOON WITH GUSTS UP OVER 20 KNOTS.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR/MVFR GRADUALLY DECREASING TO IFR
VERY LATE. PATCHY DRIZZLE POSSIBLE LATE. CLEARING RETURNS BY LATE
SAT MORNING.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WATERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM FROM 8 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 8 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION: CANEPA
MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 230009
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
509 PM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CONTINUE TO EXIT THE REGION
AS HIGH PRESSURE BUILDS. THE BUILDING HIGH PRESSURE WILL RESULT
DRIER CONDITIONS AND A SLIGHT WARMING TREND OF THROUGH EARLY NEXT
WEEK.

&&

.DISCUSSION...AS OF 2:50 PM PDT FRIDAY...CHANCE OF PRECIPITATION
CONTINUES TO DIMINISH AS A STORM SYSTEM EXITS AND HIGH PRESSURE
BUILDS. DRIER WEATHER EXPECTED WITH A SLIGHT WARMING TREND THROUGH
EARLY NEXT WEEK.

LATEST SURFACE OBSERVATIONS AND KMUX RADAR IMAGERY BOTH INDICATE
EARLIER SHOWER ACTIVITY HAS DIMINISHED ACROSS THE BAY AREA.
THEREFORE...REMOVED ANY MENTION OF SHOWERS THIS AFTERNOON AND EARLY
THIS EVENING. HOWEVER...THE VISIBLE SATELLITE DOES INDICATE
LINGERING MOISTURE...BUT MAINLY IN THE FORM OF CUMULUS
CLOUDS...ESPECIALLY OVER THE HILLS.

EXPECT THE CUMULUS CLOUDS TO GRADUALLY DISSIPATE AFTER SUNSET AS
DAYTIME HEATING ENDS. HIGH PRESSURE CURRENTLY OVER THE EPAC WILL
SLOWLY BUILDING THROUGH THE WEEKEND WITH A MORE SUMMER LIKE
PATTERN. NIGHT AND MORNING LOW CLOUDS WILL BE COMMON WITH A MORE
DEFINED MARINE LAYER. WILL KEEP THE MENTION OF DRIZZLE EARLY
SATURDAY DUE TO THE AMPLE LOW LEVEL MOISTURE. INTERESTING TO NOTE
AS WELL..THE NAM/GFS BOTH SHOW WIDESPREAD VERY LIGHT PRECIP EARLY
SATURDAY. LOOKS VERY SIMILAR TO WHAT WAS OBSERVED ON TUESDAY WITH
MANY LOCATIONS PICKING UP A HUNDREDTH OR TWO. CONF IS NOT HIGH
ENOUGH TO PUT IN WIDESPREAD DRIZZLE...BETTER SHOT ALONG THE COAST.
DESPITE THE FORECAST WARMING TREND...MUCH OF THE BAY AREA WILL
STILL BE A FEW DEGREES BELOW NORMAL. HIGHS WILL GENERALLY BE 60S
ALONG THE COAST AND 60S/70S INLAND THROUGH.

BEYOND THE HOLIDAY WEEKEND...850MB TEMPS AND 500MB HEIGHTS
CONTINUE TO RISE THROUGH MUCH OF NEXT. AS A RESULT...THE WARMING
TREND WILL LIKELY CONTINUE WITH NEAR NORMAL TEMPERATURES(80S WELL
INLAND). NIGHT AND MORNING CLOUDS WILL REMAIN WITH ONSHORE FLOW.
DRY WEATHER CONTINUES.

&&

.AVIATION...AS OF 5:07 PM PDT FRIDAY...THERE`S A MIX OF CLEAR SKIES
AND AREAS OF CLOUDS AROUND THE REGION THIS AFTERNOON. GENERALLY
CONDITIONS ARE VFR/MVFR. LOW LEVEL MOISTURE WILL LINGER INTO
TONIGHT WITH A FEW PATCHES OF DRIZZLE BECOMING POSSIBLE VERY LATE
AT NIGHT. AN UPPER LEVEL HIGH OVER THE EPAC WILL SLOWLY EDGE IN
FROM THE WEST DURING THE PERIOD. THERE`S NO SIGN OF A MARINE
INVERSION YET PER CHECK OF THE FORT ORD AND BODEGA BAY PROFILERS.
HOWEVER SUBSIDENCE ASSOCIATED WITH THE HIGH WILL RESULT IN A
GRADUAL WARMING WITHIN THE LOWER LEVELS CAUSING THE MARINE LAYER
INVERSION TO BECOME RE-ESTABLISHED OVER THE HOLIDAY WEEKEND. BY
LATE SUNDAY NIGHT INTO MONDAY 850 MB LEVEL TEMPS ARE PREDICTED TO
REACH NEAR 15C.

VICINITY OF KSFO...MVFR CIGS WITH WESTERLY WINDS GUSTY MOSTLY HOLDING
BELOW 20 KNOTS THROUGH THE EVENING. LIGHTER WINDS EXPECTED
OVERNIGHT...BUT A RETURN TO GUSTY WEST WINDS IS VERY LIKELY SAT
AFTERNOON WITH GUSTS UP OVER 20 KNOTS.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR/MVFR GRADUALLY DECREASING TO IFR
VERY LATE. PATCHY DRIZZLE POSSIBLE LATE. CLEARING RETURNS BY LATE
SAT MORNING.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WATERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM FROM 8 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 8 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION: CANEPA
MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 230009
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
509 PM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CONTINUE TO EXIT THE REGION
AS HIGH PRESSURE BUILDS. THE BUILDING HIGH PRESSURE WILL RESULT
DRIER CONDITIONS AND A SLIGHT WARMING TREND OF THROUGH EARLY NEXT
WEEK.

&&

.DISCUSSION...AS OF 2:50 PM PDT FRIDAY...CHANCE OF PRECIPITATION
CONTINUES TO DIMINISH AS A STORM SYSTEM EXITS AND HIGH PRESSURE
BUILDS. DRIER WEATHER EXPECTED WITH A SLIGHT WARMING TREND THROUGH
EARLY NEXT WEEK.

LATEST SURFACE OBSERVATIONS AND KMUX RADAR IMAGERY BOTH INDICATE
EARLIER SHOWER ACTIVITY HAS DIMINISHED ACROSS THE BAY AREA.
THEREFORE...REMOVED ANY MENTION OF SHOWERS THIS AFTERNOON AND EARLY
THIS EVENING. HOWEVER...THE VISIBLE SATELLITE DOES INDICATE
LINGERING MOISTURE...BUT MAINLY IN THE FORM OF CUMULUS
CLOUDS...ESPECIALLY OVER THE HILLS.

EXPECT THE CUMULUS CLOUDS TO GRADUALLY DISSIPATE AFTER SUNSET AS
DAYTIME HEATING ENDS. HIGH PRESSURE CURRENTLY OVER THE EPAC WILL
SLOWLY BUILDING THROUGH THE WEEKEND WITH A MORE SUMMER LIKE
PATTERN. NIGHT AND MORNING LOW CLOUDS WILL BE COMMON WITH A MORE
DEFINED MARINE LAYER. WILL KEEP THE MENTION OF DRIZZLE EARLY
SATURDAY DUE TO THE AMPLE LOW LEVEL MOISTURE. INTERESTING TO NOTE
AS WELL..THE NAM/GFS BOTH SHOW WIDESPREAD VERY LIGHT PRECIP EARLY
SATURDAY. LOOKS VERY SIMILAR TO WHAT WAS OBSERVED ON TUESDAY WITH
MANY LOCATIONS PICKING UP A HUNDREDTH OR TWO. CONF IS NOT HIGH
ENOUGH TO PUT IN WIDESPREAD DRIZZLE...BETTER SHOT ALONG THE COAST.
DESPITE THE FORECAST WARMING TREND...MUCH OF THE BAY AREA WILL
STILL BE A FEW DEGREES BELOW NORMAL. HIGHS WILL GENERALLY BE 60S
ALONG THE COAST AND 60S/70S INLAND THROUGH.

BEYOND THE HOLIDAY WEEKEND...850MB TEMPS AND 500MB HEIGHTS
CONTINUE TO RISE THROUGH MUCH OF NEXT. AS A RESULT...THE WARMING
TREND WILL LIKELY CONTINUE WITH NEAR NORMAL TEMPERATURES(80S WELL
INLAND). NIGHT AND MORNING CLOUDS WILL REMAIN WITH ONSHORE FLOW.
DRY WEATHER CONTINUES.

&&

.AVIATION...AS OF 5:07 PM PDT FRIDAY...THERE`S A MIX OF CLEAR SKIES
AND AREAS OF CLOUDS AROUND THE REGION THIS AFTERNOON. GENERALLY
CONDITIONS ARE VFR/MVFR. LOW LEVEL MOISTURE WILL LINGER INTO
TONIGHT WITH A FEW PATCHES OF DRIZZLE BECOMING POSSIBLE VERY LATE
AT NIGHT. AN UPPER LEVEL HIGH OVER THE EPAC WILL SLOWLY EDGE IN
FROM THE WEST DURING THE PERIOD. THERE`S NO SIGN OF A MARINE
INVERSION YET PER CHECK OF THE FORT ORD AND BODEGA BAY PROFILERS.
HOWEVER SUBSIDENCE ASSOCIATED WITH THE HIGH WILL RESULT IN A
GRADUAL WARMING WITHIN THE LOWER LEVELS CAUSING THE MARINE LAYER
INVERSION TO BECOME RE-ESTABLISHED OVER THE HOLIDAY WEEKEND. BY
LATE SUNDAY NIGHT INTO MONDAY 850 MB LEVEL TEMPS ARE PREDICTED TO
REACH NEAR 15C.

VICINITY OF KSFO...MVFR CIGS WITH WESTERLY WINDS GUSTY MOSTLY HOLDING
BELOW 20 KNOTS THROUGH THE EVENING. LIGHTER WINDS EXPECTED
OVERNIGHT...BUT A RETURN TO GUSTY WEST WINDS IS VERY LIKELY SAT
AFTERNOON WITH GUSTS UP OVER 20 KNOTS.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR/MVFR GRADUALLY DECREASING TO IFR
VERY LATE. PATCHY DRIZZLE POSSIBLE LATE. CLEARING RETURNS BY LATE
SAT MORNING.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WATERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM FROM 8 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 8 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION: CANEPA
MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 222135
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
235 PM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CONTINUE TO EXIT THE REGION
AS HIGH PRESSURE BUILDS. THE BUILDING HIGH PRESSURE WILL RESULT
DRIER CONDITIONS AND A SLIGHT WARMING TREND OF THROUGH EARLY NEXT
WEEK.

&&

.DISCUSSION...AS OF 2:50 PM PDT FRIDAY...CHANCE OF PRECIPITATION
CONTINUES TO DIMINISH AS A STORM SYSTEM EXITS AND HIGH PRESSURE
BUILDS. DRIER WEATHER EXPECTED WITH A SLIGHT WARMING TREND THROUGH
EARLY NEXT WEEK.

LATEST SURFACE OBSERVATIONS AND KMUX RADAR IMAGERY BOTH INDICATE
EARLIER SHOWER ACTIVITY HAS DIMINISHED ACROSS THE BAY AREA.
THEREFORE...REMOVED ANY MENTION OF SHOWERS THIS AFTERNOON AND EARLY
THIS EVENING. HOWEVER...THE VISIBLE SATELLITE DOES INDICATE
LINGERING MOISTURE...BUT MAINLY IN THE FORM OF CUMULUS
CLOUDS...ESPECIALLY OVER THE HILLS.

EXPECT THE CUMULUS CLOUDS TO GRADUALLY DISSIPATE AFTER SUNSET AS
DAYTIME HEATING ENDS. HIGH PRESSURE CURRENTLY OVER THE EPAC WILL
SLOWLY BUILDING THROUGH THE WEEKEND WITH A MORE SUMMER LIKE
PATTERN. NIGHT AND MORNING LOW CLOUDS WILL BE COMMON WITH A MORE
DEFINED MARINE LAYER. WILL KEEP THE MENTION OF DRIZZLE EARLY
SATURDAY DUE TO THE AMPLE LOW LEVEL MOISTURE. INTERESTING TO NOTE
AS WELL..THE NAM/GFS BOTH SHOW WIDESPREAD VERY LIGHT PRECIP EARLY
SATURDAY. LOOKS VERY SIMILAR TO WHAT WAS OBSERVED ON TUESDAY WITH
MANY LOCATIONS PICKING UP A HUNDREDTH OR TWO. CONF IS NOT HIGH
ENOUGH TO PUT IN WIDESPREAD DRIZZLE...BETTER SHOT ALONG THE COAST.
DESPITE THE FORECAST WARMING TREND...MUCH OF THE BAY AREA WILL
STILL BE A FEW DEGREES BELOW NORMAL. HIGHS WILL GENERALLY BE 60S
ALONG THE COAST AND 60S/70S INLAND THROUGH.

BEYOND THE HOLIDAY WEEKEND...850MB TEMPS AND 500MB HEIGHTS
CONTINUE TO RISE THROUGH MUCH OF NEXT. AS A RESULT...THE WARMING
TREND WILL LIKELY CONTINUE WITH NEAR NORMAL TEMPERATURES(80S WELL
INLAND). NIGHT AND MORNING CLOUDS WILL REMAIN WITH ONSHORE FLOW.
DRY WEATHER CONTINUES.

&&

.AVIATION...AS OF 11:00 AM PDT FRIDAY... A SLUGGISH LOW PRESSURE
SYSTEM OVER SOCAL/VEGAS REGION WILL LEAD TO INCREASED CLOUDINESS
THROUGH THE DAY TODAY. CLOUD BASES HAVE BEEN UP AND DOWN TODAY AS
AIRMASSES INTERACT WITH A GENERAL TREND OF RISING OVER THE LAST
FEW HOURS. MIXED BAG OF DIRTY VFR CIGS OR MVFR EXPECTED TODAY AT
MOST COASTAL INFLUENCED SITES... WITH EARLY RETURN OF MVFR
EXPECTED AOA 02-04Z. IFR CIGS POSSIBLE LATE TONIGHT INTO EARLY
TOMORROW MORNING AT COASTAL INFLUENCED SITES IN WAKE OF UPPER LOW.
PREDOMINATELY ONSHORE FLOW AT MOST SITES THROUGH THE PERIOD.

VICINITY OF KSFO...INTERMITTENT VFR/HIGH BASED MVFR TODAY WITH
EARLY RETURN OF MVFR CIGS THIS EVENING. ONSHORE FLOW 10 TO 15 KT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS... DIRTY VFR WITH BKN-OVC CLOUDS
4000FT AND ABOVE THROUGH THE DAY. MVFR CIGS RETURN 02-04Z WITH IFR
POSBL AFTER 10Z.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WATERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.HYDROLOGY...

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM FROM 8 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 8 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 222135
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
235 PM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CONTINUE TO EXIT THE REGION
AS HIGH PRESSURE BUILDS. THE BUILDING HIGH PRESSURE WILL RESULT
DRIER CONDITIONS AND A SLIGHT WARMING TREND OF THROUGH EARLY NEXT
WEEK.

&&

.DISCUSSION...AS OF 2:50 PM PDT FRIDAY...CHANCE OF PRECIPITATION
CONTINUES TO DIMINISH AS A STORM SYSTEM EXITS AND HIGH PRESSURE
BUILDS. DRIER WEATHER EXPECTED WITH A SLIGHT WARMING TREND THROUGH
EARLY NEXT WEEK.

LATEST SURFACE OBSERVATIONS AND KMUX RADAR IMAGERY BOTH INDICATE
EARLIER SHOWER ACTIVITY HAS DIMINISHED ACROSS THE BAY AREA.
THEREFORE...REMOVED ANY MENTION OF SHOWERS THIS AFTERNOON AND EARLY
THIS EVENING. HOWEVER...THE VISIBLE SATELLITE DOES INDICATE
LINGERING MOISTURE...BUT MAINLY IN THE FORM OF CUMULUS
CLOUDS...ESPECIALLY OVER THE HILLS.

EXPECT THE CUMULUS CLOUDS TO GRADUALLY DISSIPATE AFTER SUNSET AS
DAYTIME HEATING ENDS. HIGH PRESSURE CURRENTLY OVER THE EPAC WILL
SLOWLY BUILDING THROUGH THE WEEKEND WITH A MORE SUMMER LIKE
PATTERN. NIGHT AND MORNING LOW CLOUDS WILL BE COMMON WITH A MORE
DEFINED MARINE LAYER. WILL KEEP THE MENTION OF DRIZZLE EARLY
SATURDAY DUE TO THE AMPLE LOW LEVEL MOISTURE. INTERESTING TO NOTE
AS WELL..THE NAM/GFS BOTH SHOW WIDESPREAD VERY LIGHT PRECIP EARLY
SATURDAY. LOOKS VERY SIMILAR TO WHAT WAS OBSERVED ON TUESDAY WITH
MANY LOCATIONS PICKING UP A HUNDREDTH OR TWO. CONF IS NOT HIGH
ENOUGH TO PUT IN WIDESPREAD DRIZZLE...BETTER SHOT ALONG THE COAST.
DESPITE THE FORECAST WARMING TREND...MUCH OF THE BAY AREA WILL
STILL BE A FEW DEGREES BELOW NORMAL. HIGHS WILL GENERALLY BE 60S
ALONG THE COAST AND 60S/70S INLAND THROUGH.

BEYOND THE HOLIDAY WEEKEND...850MB TEMPS AND 500MB HEIGHTS
CONTINUE TO RISE THROUGH MUCH OF NEXT. AS A RESULT...THE WARMING
TREND WILL LIKELY CONTINUE WITH NEAR NORMAL TEMPERATURES(80S WELL
INLAND). NIGHT AND MORNING CLOUDS WILL REMAIN WITH ONSHORE FLOW.
DRY WEATHER CONTINUES.

&&

.AVIATION...AS OF 11:00 AM PDT FRIDAY... A SLUGGISH LOW PRESSURE
SYSTEM OVER SOCAL/VEGAS REGION WILL LEAD TO INCREASED CLOUDINESS
THROUGH THE DAY TODAY. CLOUD BASES HAVE BEEN UP AND DOWN TODAY AS
AIRMASSES INTERACT WITH A GENERAL TREND OF RISING OVER THE LAST
FEW HOURS. MIXED BAG OF DIRTY VFR CIGS OR MVFR EXPECTED TODAY AT
MOST COASTAL INFLUENCED SITES... WITH EARLY RETURN OF MVFR
EXPECTED AOA 02-04Z. IFR CIGS POSSIBLE LATE TONIGHT INTO EARLY
TOMORROW MORNING AT COASTAL INFLUENCED SITES IN WAKE OF UPPER LOW.
PREDOMINATELY ONSHORE FLOW AT MOST SITES THROUGH THE PERIOD.

VICINITY OF KSFO...INTERMITTENT VFR/HIGH BASED MVFR TODAY WITH
EARLY RETURN OF MVFR CIGS THIS EVENING. ONSHORE FLOW 10 TO 15 KT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS... DIRTY VFR WITH BKN-OVC CLOUDS
4000FT AND ABOVE THROUGH THE DAY. MVFR CIGS RETURN 02-04Z WITH IFR
POSBL AFTER 10Z.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WATERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.HYDROLOGY...

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM FROM 8 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 8 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA








000
FXUS66 KMTR 222135
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
235 PM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CONTINUE TO EXIT THE REGION
AS HIGH PRESSURE BUILDS. THE BUILDING HIGH PRESSURE WILL RESULT
DRIER CONDITIONS AND A SLIGHT WARMING TREND OF THROUGH EARLY NEXT
WEEK.

&&

.DISCUSSION...AS OF 2:50 PM PDT FRIDAY...CHANCE OF PRECIPITATION
CONTINUES TO DIMINISH AS A STORM SYSTEM EXITS AND HIGH PRESSURE
BUILDS. DRIER WEATHER EXPECTED WITH A SLIGHT WARMING TREND THROUGH
EARLY NEXT WEEK.

LATEST SURFACE OBSERVATIONS AND KMUX RADAR IMAGERY BOTH INDICATE
EARLIER SHOWER ACTIVITY HAS DIMINISHED ACROSS THE BAY AREA.
THEREFORE...REMOVED ANY MENTION OF SHOWERS THIS AFTERNOON AND EARLY
THIS EVENING. HOWEVER...THE VISIBLE SATELLITE DOES INDICATE
LINGERING MOISTURE...BUT MAINLY IN THE FORM OF CUMULUS
CLOUDS...ESPECIALLY OVER THE HILLS.

EXPECT THE CUMULUS CLOUDS TO GRADUALLY DISSIPATE AFTER SUNSET AS
DAYTIME HEATING ENDS. HIGH PRESSURE CURRENTLY OVER THE EPAC WILL
SLOWLY BUILDING THROUGH THE WEEKEND WITH A MORE SUMMER LIKE
PATTERN. NIGHT AND MORNING LOW CLOUDS WILL BE COMMON WITH A MORE
DEFINED MARINE LAYER. WILL KEEP THE MENTION OF DRIZZLE EARLY
SATURDAY DUE TO THE AMPLE LOW LEVEL MOISTURE. INTERESTING TO NOTE
AS WELL..THE NAM/GFS BOTH SHOW WIDESPREAD VERY LIGHT PRECIP EARLY
SATURDAY. LOOKS VERY SIMILAR TO WHAT WAS OBSERVED ON TUESDAY WITH
MANY LOCATIONS PICKING UP A HUNDREDTH OR TWO. CONF IS NOT HIGH
ENOUGH TO PUT IN WIDESPREAD DRIZZLE...BETTER SHOT ALONG THE COAST.
DESPITE THE FORECAST WARMING TREND...MUCH OF THE BAY AREA WILL
STILL BE A FEW DEGREES BELOW NORMAL. HIGHS WILL GENERALLY BE 60S
ALONG THE COAST AND 60S/70S INLAND THROUGH.

BEYOND THE HOLIDAY WEEKEND...850MB TEMPS AND 500MB HEIGHTS
CONTINUE TO RISE THROUGH MUCH OF NEXT. AS A RESULT...THE WARMING
TREND WILL LIKELY CONTINUE WITH NEAR NORMAL TEMPERATURES(80S WELL
INLAND). NIGHT AND MORNING CLOUDS WILL REMAIN WITH ONSHORE FLOW.
DRY WEATHER CONTINUES.

&&

.AVIATION...AS OF 11:00 AM PDT FRIDAY... A SLUGGISH LOW PRESSURE
SYSTEM OVER SOCAL/VEGAS REGION WILL LEAD TO INCREASED CLOUDINESS
THROUGH THE DAY TODAY. CLOUD BASES HAVE BEEN UP AND DOWN TODAY AS
AIRMASSES INTERACT WITH A GENERAL TREND OF RISING OVER THE LAST
FEW HOURS. MIXED BAG OF DIRTY VFR CIGS OR MVFR EXPECTED TODAY AT
MOST COASTAL INFLUENCED SITES... WITH EARLY RETURN OF MVFR
EXPECTED AOA 02-04Z. IFR CIGS POSSIBLE LATE TONIGHT INTO EARLY
TOMORROW MORNING AT COASTAL INFLUENCED SITES IN WAKE OF UPPER LOW.
PREDOMINATELY ONSHORE FLOW AT MOST SITES THROUGH THE PERIOD.

VICINITY OF KSFO...INTERMITTENT VFR/HIGH BASED MVFR TODAY WITH
EARLY RETURN OF MVFR CIGS THIS EVENING. ONSHORE FLOW 10 TO 15 KT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS... DIRTY VFR WITH BKN-OVC CLOUDS
4000FT AND ABOVE THROUGH THE DAY. MVFR CIGS RETURN 02-04Z WITH IFR
POSBL AFTER 10Z.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WATERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.HYDROLOGY...

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM FROM 8 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 8 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 222135
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
235 PM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CONTINUE TO EXIT THE REGION
AS HIGH PRESSURE BUILDS. THE BUILDING HIGH PRESSURE WILL RESULT
DRIER CONDITIONS AND A SLIGHT WARMING TREND OF THROUGH EARLY NEXT
WEEK.

&&

.DISCUSSION...AS OF 2:50 PM PDT FRIDAY...CHANCE OF PRECIPITATION
CONTINUES TO DIMINISH AS A STORM SYSTEM EXITS AND HIGH PRESSURE
BUILDS. DRIER WEATHER EXPECTED WITH A SLIGHT WARMING TREND THROUGH
EARLY NEXT WEEK.

LATEST SURFACE OBSERVATIONS AND KMUX RADAR IMAGERY BOTH INDICATE
EARLIER SHOWER ACTIVITY HAS DIMINISHED ACROSS THE BAY AREA.
THEREFORE...REMOVED ANY MENTION OF SHOWERS THIS AFTERNOON AND EARLY
THIS EVENING. HOWEVER...THE VISIBLE SATELLITE DOES INDICATE
LINGERING MOISTURE...BUT MAINLY IN THE FORM OF CUMULUS
CLOUDS...ESPECIALLY OVER THE HILLS.

EXPECT THE CUMULUS CLOUDS TO GRADUALLY DISSIPATE AFTER SUNSET AS
DAYTIME HEATING ENDS. HIGH PRESSURE CURRENTLY OVER THE EPAC WILL
SLOWLY BUILDING THROUGH THE WEEKEND WITH A MORE SUMMER LIKE
PATTERN. NIGHT AND MORNING LOW CLOUDS WILL BE COMMON WITH A MORE
DEFINED MARINE LAYER. WILL KEEP THE MENTION OF DRIZZLE EARLY
SATURDAY DUE TO THE AMPLE LOW LEVEL MOISTURE. INTERESTING TO NOTE
AS WELL..THE NAM/GFS BOTH SHOW WIDESPREAD VERY LIGHT PRECIP EARLY
SATURDAY. LOOKS VERY SIMILAR TO WHAT WAS OBSERVED ON TUESDAY WITH
MANY LOCATIONS PICKING UP A HUNDREDTH OR TWO. CONF IS NOT HIGH
ENOUGH TO PUT IN WIDESPREAD DRIZZLE...BETTER SHOT ALONG THE COAST.
DESPITE THE FORECAST WARMING TREND...MUCH OF THE BAY AREA WILL
STILL BE A FEW DEGREES BELOW NORMAL. HIGHS WILL GENERALLY BE 60S
ALONG THE COAST AND 60S/70S INLAND THROUGH.

BEYOND THE HOLIDAY WEEKEND...850MB TEMPS AND 500MB HEIGHTS
CONTINUE TO RISE THROUGH MUCH OF NEXT. AS A RESULT...THE WARMING
TREND WILL LIKELY CONTINUE WITH NEAR NORMAL TEMPERATURES(80S WELL
INLAND). NIGHT AND MORNING CLOUDS WILL REMAIN WITH ONSHORE FLOW.
DRY WEATHER CONTINUES.

&&

.AVIATION...AS OF 11:00 AM PDT FRIDAY... A SLUGGISH LOW PRESSURE
SYSTEM OVER SOCAL/VEGAS REGION WILL LEAD TO INCREASED CLOUDINESS
THROUGH THE DAY TODAY. CLOUD BASES HAVE BEEN UP AND DOWN TODAY AS
AIRMASSES INTERACT WITH A GENERAL TREND OF RISING OVER THE LAST
FEW HOURS. MIXED BAG OF DIRTY VFR CIGS OR MVFR EXPECTED TODAY AT
MOST COASTAL INFLUENCED SITES... WITH EARLY RETURN OF MVFR
EXPECTED AOA 02-04Z. IFR CIGS POSSIBLE LATE TONIGHT INTO EARLY
TOMORROW MORNING AT COASTAL INFLUENCED SITES IN WAKE OF UPPER LOW.
PREDOMINATELY ONSHORE FLOW AT MOST SITES THROUGH THE PERIOD.

VICINITY OF KSFO...INTERMITTENT VFR/HIGH BASED MVFR TODAY WITH
EARLY RETURN OF MVFR CIGS THIS EVENING. ONSHORE FLOW 10 TO 15 KT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS... DIRTY VFR WITH BKN-OVC CLOUDS
4000FT AND ABOVE THROUGH THE DAY. MVFR CIGS RETURN 02-04Z WITH IFR
POSBL AFTER 10Z.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WATERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.HYDROLOGY...

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM FROM 8 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 8 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA








000
FXUS66 KMTR 221804
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1104 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 08:38 AM PDT FRIDAY...THE OVERALL WEATHER
PICTURE THIS MORNING IS VERY SIMILAR TO YESTERDAY...A MIX OF SUN
AND CLOUDS WITH SCATTERED SHOWERS. THE LONGWAVE PATTERN SHOWS
RIDGING OVER EPAC WITH AN UPPER TROUGH SWINGING THROUGH SOCAL INTO
S NEVADA. THE UPPER LOW IS THE LIKELY CAUSE FOR THIS MORNING/S
LIGHT SHOWER ACTIVITY AS WRAP-AROUND MOISTURE STREAMS OVER THE BAY
AREA. KMUX IMAGERY KEEP MOST SHOWER ACTIVITY CONFINED FROM ROUGHLY
SUNNYVALE SOUTHWARD. RAINFALL AMOUNTS OVER THE PAST 12 HOURS HAVE
MOSTLY BEEN A FEW HUNDREDTHS WITH THE HIGHER AMOUNTS OVER THE
SANTA CRUZ MOUNTAINS.

FOR THE REST OF TODAY...SCATTERED SHOWERS WILL BE POSSIBLE FOR
MUCH OF THE REGION...BUT THE HIGHEST PROBABILITY FOR SHOWERS WILL
BE SOUTH OF SF BAY. AN ADDITIONAL FEW HUNDREDTHS WILL BE
POSSIBLE.

PRECIP CHANCES TAPER OFF OVERNIGHT WITH DRIER AND SLIGHTLY WARMER
WEATHER EXPECTED OVER THE HOLIDAY WEEKEND.

&&

.AVIATION...AS OF 11:00 AM PDT FRIDAY... A SLUGGISH LOW PRESSURE
SYSTEM OVER SOCAL/VEGAS REGION WILL LEAD TO INCREASED CLOUDINESS
THROUGH THE DAY TODAY. CLOUD BASES HAVE BEEN UP AND DOWN TODAY AS
AIRMASSES INTERACT WITH A GENERAL TREND OF RISING OVER THE LAST
FEW HOURS. MIXED BAG OF DIRTY VFR CIGS OR MVFR EXPECTED TODAY AT
MOST COASTAL INFLUENCED SITES... WITH EARLY RETURN OF MVFR
EXPECTED AOA 02-04Z. IFR CIGS POSSIBLE LATE TONIGHT INTO EARLY
TOMORROW MORNING AT COASTAL INFLUENCED SITES IN WAKE OF UPPER LOW.
PREDMINATELY ONSHORE FLOW AT MOST SITES THROUGH THE PERIOD.

VICINITY OF KSFO...INTERMITTANT VFR/HIGH BASED MVFR TODAY WITH
EARLY RETURN OF MVFR CIGS THIS EVENING. ONSHORE FLOW 10 TO 15 KT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS... DIRTY VFR WITH BKN-OVC CLOUDS
4000FT AND ABOVE THROUGH THE DAY. MVFR CIGS RETURN 02-04Z WITH IFR
POSBL AFTER 10Z.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WTERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.HYDROLOGY...

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 221804
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1104 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 08:38 AM PDT FRIDAY...THE OVERALL WEATHER
PICTURE THIS MORNING IS VERY SIMILAR TO YESTERDAY...A MIX OF SUN
AND CLOUDS WITH SCATTERED SHOWERS. THE LONGWAVE PATTERN SHOWS
RIDGING OVER EPAC WITH AN UPPER TROUGH SWINGING THROUGH SOCAL INTO
S NEVADA. THE UPPER LOW IS THE LIKELY CAUSE FOR THIS MORNING/S
LIGHT SHOWER ACTIVITY AS WRAP-AROUND MOISTURE STREAMS OVER THE BAY
AREA. KMUX IMAGERY KEEP MOST SHOWER ACTIVITY CONFINED FROM ROUGHLY
SUNNYVALE SOUTHWARD. RAINFALL AMOUNTS OVER THE PAST 12 HOURS HAVE
MOSTLY BEEN A FEW HUNDREDTHS WITH THE HIGHER AMOUNTS OVER THE
SANTA CRUZ MOUNTAINS.

FOR THE REST OF TODAY...SCATTERED SHOWERS WILL BE POSSIBLE FOR
MUCH OF THE REGION...BUT THE HIGHEST PROBABILITY FOR SHOWERS WILL
BE SOUTH OF SF BAY. AN ADDITIONAL FEW HUNDREDTHS WILL BE
POSSIBLE.

PRECIP CHANCES TAPER OFF OVERNIGHT WITH DRIER AND SLIGHTLY WARMER
WEATHER EXPECTED OVER THE HOLIDAY WEEKEND.

&&

.AVIATION...AS OF 11:00 AM PDT FRIDAY... A SLUGGISH LOW PRESSURE
SYSTEM OVER SOCAL/VEGAS REGION WILL LEAD TO INCREASED CLOUDINESS
THROUGH THE DAY TODAY. CLOUD BASES HAVE BEEN UP AND DOWN TODAY AS
AIRMASSES INTERACT WITH A GENERAL TREND OF RISING OVER THE LAST
FEW HOURS. MIXED BAG OF DIRTY VFR CIGS OR MVFR EXPECTED TODAY AT
MOST COASTAL INFLUENCED SITES... WITH EARLY RETURN OF MVFR
EXPECTED AOA 02-04Z. IFR CIGS POSSIBLE LATE TONIGHT INTO EARLY
TOMORROW MORNING AT COASTAL INFLUENCED SITES IN WAKE OF UPPER LOW.
PREDMINATELY ONSHORE FLOW AT MOST SITES THROUGH THE PERIOD.

VICINITY OF KSFO...INTERMITTANT VFR/HIGH BASED MVFR TODAY WITH
EARLY RETURN OF MVFR CIGS THIS EVENING. ONSHORE FLOW 10 TO 15 KT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS... DIRTY VFR WITH BKN-OVC CLOUDS
4000FT AND ABOVE THROUGH THE DAY. MVFR CIGS RETURN 02-04Z WITH IFR
POSBL AFTER 10Z.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WTERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.HYDROLOGY...

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 221804
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1104 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 08:38 AM PDT FRIDAY...THE OVERALL WEATHER
PICTURE THIS MORNING IS VERY SIMILAR TO YESTERDAY...A MIX OF SUN
AND CLOUDS WITH SCATTERED SHOWERS. THE LONGWAVE PATTERN SHOWS
RIDGING OVER EPAC WITH AN UPPER TROUGH SWINGING THROUGH SOCAL INTO
S NEVADA. THE UPPER LOW IS THE LIKELY CAUSE FOR THIS MORNING/S
LIGHT SHOWER ACTIVITY AS WRAP-AROUND MOISTURE STREAMS OVER THE BAY
AREA. KMUX IMAGERY KEEP MOST SHOWER ACTIVITY CONFINED FROM ROUGHLY
SUNNYVALE SOUTHWARD. RAINFALL AMOUNTS OVER THE PAST 12 HOURS HAVE
MOSTLY BEEN A FEW HUNDREDTHS WITH THE HIGHER AMOUNTS OVER THE
SANTA CRUZ MOUNTAINS.

FOR THE REST OF TODAY...SCATTERED SHOWERS WILL BE POSSIBLE FOR
MUCH OF THE REGION...BUT THE HIGHEST PROBABILITY FOR SHOWERS WILL
BE SOUTH OF SF BAY. AN ADDITIONAL FEW HUNDREDTHS WILL BE
POSSIBLE.

PRECIP CHANCES TAPER OFF OVERNIGHT WITH DRIER AND SLIGHTLY WARMER
WEATHER EXPECTED OVER THE HOLIDAY WEEKEND.

&&

.AVIATION...AS OF 11:00 AM PDT FRIDAY... A SLUGGISH LOW PRESSURE
SYSTEM OVER SOCAL/VEGAS REGION WILL LEAD TO INCREASED CLOUDINESS
THROUGH THE DAY TODAY. CLOUD BASES HAVE BEEN UP AND DOWN TODAY AS
AIRMASSES INTERACT WITH A GENERAL TREND OF RISING OVER THE LAST
FEW HOURS. MIXED BAG OF DIRTY VFR CIGS OR MVFR EXPECTED TODAY AT
MOST COASTAL INFLUENCED SITES... WITH EARLY RETURN OF MVFR
EXPECTED AOA 02-04Z. IFR CIGS POSSIBLE LATE TONIGHT INTO EARLY
TOMORROW MORNING AT COASTAL INFLUENCED SITES IN WAKE OF UPPER LOW.
PREDMINATELY ONSHORE FLOW AT MOST SITES THROUGH THE PERIOD.

VICINITY OF KSFO...INTERMITTANT VFR/HIGH BASED MVFR TODAY WITH
EARLY RETURN OF MVFR CIGS THIS EVENING. ONSHORE FLOW 10 TO 15 KT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS... DIRTY VFR WITH BKN-OVC CLOUDS
4000FT AND ABOVE THROUGH THE DAY. MVFR CIGS RETURN 02-04Z WITH IFR
POSBL AFTER 10Z.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WTERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.HYDROLOGY...

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 221804
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1104 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 08:38 AM PDT FRIDAY...THE OVERALL WEATHER
PICTURE THIS MORNING IS VERY SIMILAR TO YESTERDAY...A MIX OF SUN
AND CLOUDS WITH SCATTERED SHOWERS. THE LONGWAVE PATTERN SHOWS
RIDGING OVER EPAC WITH AN UPPER TROUGH SWINGING THROUGH SOCAL INTO
S NEVADA. THE UPPER LOW IS THE LIKELY CAUSE FOR THIS MORNING/S
LIGHT SHOWER ACTIVITY AS WRAP-AROUND MOISTURE STREAMS OVER THE BAY
AREA. KMUX IMAGERY KEEP MOST SHOWER ACTIVITY CONFINED FROM ROUGHLY
SUNNYVALE SOUTHWARD. RAINFALL AMOUNTS OVER THE PAST 12 HOURS HAVE
MOSTLY BEEN A FEW HUNDREDTHS WITH THE HIGHER AMOUNTS OVER THE
SANTA CRUZ MOUNTAINS.

FOR THE REST OF TODAY...SCATTERED SHOWERS WILL BE POSSIBLE FOR
MUCH OF THE REGION...BUT THE HIGHEST PROBABILITY FOR SHOWERS WILL
BE SOUTH OF SF BAY. AN ADDITIONAL FEW HUNDREDTHS WILL BE
POSSIBLE.

PRECIP CHANCES TAPER OFF OVERNIGHT WITH DRIER AND SLIGHTLY WARMER
WEATHER EXPECTED OVER THE HOLIDAY WEEKEND.

&&

.AVIATION...AS OF 11:00 AM PDT FRIDAY... A SLUGGISH LOW PRESSURE
SYSTEM OVER SOCAL/VEGAS REGION WILL LEAD TO INCREASED CLOUDINESS
THROUGH THE DAY TODAY. CLOUD BASES HAVE BEEN UP AND DOWN TODAY AS
AIRMASSES INTERACT WITH A GENERAL TREND OF RISING OVER THE LAST
FEW HOURS. MIXED BAG OF DIRTY VFR CIGS OR MVFR EXPECTED TODAY AT
MOST COASTAL INFLUENCED SITES... WITH EARLY RETURN OF MVFR
EXPECTED AOA 02-04Z. IFR CIGS POSSIBLE LATE TONIGHT INTO EARLY
TOMORROW MORNING AT COASTAL INFLUENCED SITES IN WAKE OF UPPER LOW.
PREDMINATELY ONSHORE FLOW AT MOST SITES THROUGH THE PERIOD.

VICINITY OF KSFO...INTERMITTANT VFR/HIGH BASED MVFR TODAY WITH
EARLY RETURN OF MVFR CIGS THIS EVENING. ONSHORE FLOW 10 TO 15 KT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS... DIRTY VFR WITH BKN-OVC CLOUDS
4000FT AND ABOVE THROUGH THE DAY. MVFR CIGS RETURN 02-04Z WITH IFR
POSBL AFTER 10Z.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 10:53 AM PDT FRIDAY...NORTHWEST WINDS WILL
INCREASE LATER TODAY AS THE PRESSURE GRADIENT TIGHTENS. SEAS WILL
ALSO BUILD OVER THE NEXT 24 HOURS LEADING TO GENERALLY
DETERIORATING CONDITIONS OVER THE COASTAL WTERS INTO THE WEEKEND.
UNFAVORABLE WINDS AND SEAS PERSIST THROUGH THE WEEKEND BEFORE
BEGINNING TO TAPER OFF EARLY NEXT WEEK.

&&

.HYDROLOGY...

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: DRP

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 221551
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
851 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 08:38 AM PDT FRIDAY...THE OVERALL WEATHER
PICTURE THIS MORNING IS VERY SIMILAR TO YESTERDAY...A MIX OF SUN
AND CLOUDS WITH SCATTERED SHOWERS. THE LONGWAVE PATTERN SHOWS
RIDGING OVER EPAC WITH AN UPPER TROUGH SWINGING THROUGH SOCAL INTO
S NEVADA. THE UPPER LOW IS THE LIKELY CAUSE FOR THIS MORNING/S
LIGHT SHOWER ACTIVITY AS WRAP-AROUND MOISTURE STREAMS OVER THE BAY
AREA. KMUX IMAGERY KEEP MOST SHOWER ACTIVITY CONFINED FROM ROUGHLY
SUNNYVALE SOUTHWARD. RAINFALL AMOUNTS OVER THE PAST 12 HOURS HAVE
MOSTLY BEEN A FEW HUNDREDTHS WITH THE HIGHER AMOUNTS OVER THE
SANTA CRUZ MOUNTAINS.

FOR THE REST OF TODAY...SCATTERED SHOWERS WILL BE POSSIBLE FOR
MUCH OF THE REGION...BUT THE HIGHEST PROBABILITY FOR SHOWERS WILL
BE SOUTH OF SF BAY. AN ADDITIONAL FEW HUNDREDTHS WILL BE
POSSIBLE.

PRECIP CHANCES TAPER OFF OVERNIGHT WITH DRIER AND SLIGHTLY WARMER
WEATHER EXPECTED OVER THE HOLIDAY WEEKEND.


&&

.AVIATION...AS OF 4:49 AM PDT FRIDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUDY
CONDITIONS OVER THE TERMINALS TODAY.

VICINITY OF KSFO...MVFR CIGS BKN-OVC025 ARE EXPECTED TO PREVAIL
TODAY. CONDITIONS ARE ANTICIPATED TO BECOME BKN-OVC015 BY AROUND
0300Z. WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CONDITIONS BKN-OVC025 ARE
ANTICIPATED TO IMPROVE TO VFR SCT025 BKN050 THIS AFTERNOON. OVC015
WILL RETURN BY AROUND 0300Z. WESTERLY WINDS WILL REACH 10 KT THIS
AFTERNOON WITH GUSTS TO 15KT.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:07 AM PDT FRIDAY...GENERALLY LIGHT WINDS WILL
PREVAIL TODAY BUT ARE EXPECTED TO INCREASE OUT OF THE NORTHWEST
THIS EVENING AS THE SURFACE PRESSURE GRADIENT INCREASES. THE
INCREASING WINDS WILL RESULT IN DETERIORATING SEA CONDITIONS.
WINDS ARE ANTICIPATED TO STAY UP THIS WEEKEND BUT THE FORECAST
CALLS FOR DECREASING WINDS AND IMPROVING SEA CONDITIONS FOR
MEMORIAL DAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA








000
FXUS66 KMTR 221551
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
851 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 08:38 AM PDT FRIDAY...THE OVERALL WEATHER
PICTURE THIS MORNING IS VERY SIMILAR TO YESTERDAY...A MIX OF SUN
AND CLOUDS WITH SCATTERED SHOWERS. THE LONGWAVE PATTERN SHOWS
RIDGING OVER EPAC WITH AN UPPER TROUGH SWINGING THROUGH SOCAL INTO
S NEVADA. THE UPPER LOW IS THE LIKELY CAUSE FOR THIS MORNING/S
LIGHT SHOWER ACTIVITY AS WRAP-AROUND MOISTURE STREAMS OVER THE BAY
AREA. KMUX IMAGERY KEEP MOST SHOWER ACTIVITY CONFINED FROM ROUGHLY
SUNNYVALE SOUTHWARD. RAINFALL AMOUNTS OVER THE PAST 12 HOURS HAVE
MOSTLY BEEN A FEW HUNDREDTHS WITH THE HIGHER AMOUNTS OVER THE
SANTA CRUZ MOUNTAINS.

FOR THE REST OF TODAY...SCATTERED SHOWERS WILL BE POSSIBLE FOR
MUCH OF THE REGION...BUT THE HIGHEST PROBABILITY FOR SHOWERS WILL
BE SOUTH OF SF BAY. AN ADDITIONAL FEW HUNDREDTHS WILL BE
POSSIBLE.

PRECIP CHANCES TAPER OFF OVERNIGHT WITH DRIER AND SLIGHTLY WARMER
WEATHER EXPECTED OVER THE HOLIDAY WEEKEND.


&&

.AVIATION...AS OF 4:49 AM PDT FRIDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUDY
CONDITIONS OVER THE TERMINALS TODAY.

VICINITY OF KSFO...MVFR CIGS BKN-OVC025 ARE EXPECTED TO PREVAIL
TODAY. CONDITIONS ARE ANTICIPATED TO BECOME BKN-OVC015 BY AROUND
0300Z. WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CONDITIONS BKN-OVC025 ARE
ANTICIPATED TO IMPROVE TO VFR SCT025 BKN050 THIS AFTERNOON. OVC015
WILL RETURN BY AROUND 0300Z. WESTERLY WINDS WILL REACH 10 KT THIS
AFTERNOON WITH GUSTS TO 15KT.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:07 AM PDT FRIDAY...GENERALLY LIGHT WINDS WILL
PREVAIL TODAY BUT ARE EXPECTED TO INCREASE OUT OF THE NORTHWEST
THIS EVENING AS THE SURFACE PRESSURE GRADIENT INCREASES. THE
INCREASING WINDS WILL RESULT IN DETERIORATING SEA CONDITIONS.
WINDS ARE ANTICIPATED TO STAY UP THIS WEEKEND BUT THE FORECAST
CALLS FOR DECREASING WINDS AND IMPROVING SEA CONDITIONS FOR
MEMORIAL DAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA









000
FXUS66 KMTR 221149
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
449 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 3:20 AM PDT FRIDAY...THE UPPER LEVEL LOW THAT
BROUGHT SOME LIGHT SHOWERS TO THE AREA YESTERDAY HAS NOW MOVED TO
THE SOUTH AND IS CURRENTLY OFF THE SOUTHERN CALIFORNIA COAST. SOME
WRAP-AROUND MOISTURE IS KEEPING SHOWER ACTIVITY GOING IN THE NORTHERN
SIERRA AS WELL AS OVER THE SAN LUIS OBISPO/KERN COUNTY BORDER. A
SLIGHT CHANCE OF LIGHT RAIN SHOWERS IS POSSIBLE AGAIN TODAY OVER
PORTIONS OF THE DISTRICT TODAY...AND INTO THIS EVENING ACROSS THE
FAR EASTERN SECTIONS. HIGHS TODAY ARE EXPECTED TO BE SIMILAR TO
THOSE ON THURSDAY...COOL WITH LOWER 60S AT THE COAST TO THE 70S
INLAND.

THE UPPER LOW IS PROGGED TO MOVE OVER NORTHERN ARIZONA BY LATE
FRIDAY NIGHT...AND SHOWER CHANCES ACROSS OUR DISTRICT WILL
DIMINISH. THERE MAY BE SOME PATCHY COASTAL DRIZZLE SATURDAY
MORNING BUT THAT WILL BE IT.

A SLIGHT WARMING TREND IS INDICATED BEGINNING SATURDAY AND
CONTINUING INTO EARLY NEXT WEEK AS WEAK HIGH PRESSURE BUILDS ALONG
THE COAST. THE MARINE LAYER WILL BECOME EVEN MORE COMPRESSED
ALLOWING AREAS AWAY FROM THE COAST TO WARM BACK UP TO NEAR NORMAL
VALUES. MEDIUM RANGE MODELS INDICATE CONTINUED DRY CONDITIONS
WITH NEAR NORMAL TEMPERATURES THROUGH NEXT WEEK.

&&

.AVIATION...AS OF 4:49 AM PDT FRIDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUDY
CONDITIONS OVER THE TERMINALS TODAY.

VICINITY OF KSFO...MVFR CIGS BKN-OVC025 ARE EXPECTED TO PREVAIL
TODAY. CONDITIONS ARE ANTICIPATED TO BECOME BKN-OVC015 BY AROUND
0300Z. WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CONDITIONS BKN-OVC025 ARE
ANTICIPATED TO IMPROVE TO VFR SCT025 BKN050 THIS AFTERNOON. OVC015
WILL RETURN BY AROUND 0300Z. WESTERLY WINDS WILL REACH 10 KT THIS
AFTERNOON WITH GUSTS TO 15KT.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:07 AM PDT FRIDAY...GENERALLY LIGHT WINDS WILL
PREVAIL TODAY BUT ARE EXPECTED TO INCREASE OUT OF THE NORTHWEST
THIS EVENING AS THE SURFACE PRESSURE GRADIENT INCREASES. THE
INCREASING WINDS WILL RESULT IN DETERIORATING SEA CONDITIONS.
WINDS ARE ANTICIPATED TO STAY UP THIS WEEKEND BUT THE FORECAST
CALLS FOR DECREASING WINDS AND IMPROVING SEA CONDITIONS FOR
MEMORIAL DAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 221149
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
449 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 3:20 AM PDT FRIDAY...THE UPPER LEVEL LOW THAT
BROUGHT SOME LIGHT SHOWERS TO THE AREA YESTERDAY HAS NOW MOVED TO
THE SOUTH AND IS CURRENTLY OFF THE SOUTHERN CALIFORNIA COAST. SOME
WRAP-AROUND MOISTURE IS KEEPING SHOWER ACTIVITY GOING IN THE NORTHERN
SIERRA AS WELL AS OVER THE SAN LUIS OBISPO/KERN COUNTY BORDER. A
SLIGHT CHANCE OF LIGHT RAIN SHOWERS IS POSSIBLE AGAIN TODAY OVER
PORTIONS OF THE DISTRICT TODAY...AND INTO THIS EVENING ACROSS THE
FAR EASTERN SECTIONS. HIGHS TODAY ARE EXPECTED TO BE SIMILAR TO
THOSE ON THURSDAY...COOL WITH LOWER 60S AT THE COAST TO THE 70S
INLAND.

THE UPPER LOW IS PROGGED TO MOVE OVER NORTHERN ARIZONA BY LATE
FRIDAY NIGHT...AND SHOWER CHANCES ACROSS OUR DISTRICT WILL
DIMINISH. THERE MAY BE SOME PATCHY COASTAL DRIZZLE SATURDAY
MORNING BUT THAT WILL BE IT.

A SLIGHT WARMING TREND IS INDICATED BEGINNING SATURDAY AND
CONTINUING INTO EARLY NEXT WEEK AS WEAK HIGH PRESSURE BUILDS ALONG
THE COAST. THE MARINE LAYER WILL BECOME EVEN MORE COMPRESSED
ALLOWING AREAS AWAY FROM THE COAST TO WARM BACK UP TO NEAR NORMAL
VALUES. MEDIUM RANGE MODELS INDICATE CONTINUED DRY CONDITIONS
WITH NEAR NORMAL TEMPERATURES THROUGH NEXT WEEK.

&&

.AVIATION...AS OF 4:49 AM PDT FRIDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUDY
CONDITIONS OVER THE TERMINALS TODAY.

VICINITY OF KSFO...MVFR CIGS BKN-OVC025 ARE EXPECTED TO PREVAIL
TODAY. CONDITIONS ARE ANTICIPATED TO BECOME BKN-OVC015 BY AROUND
0300Z. WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CONDITIONS BKN-OVC025 ARE
ANTICIPATED TO IMPROVE TO VFR SCT025 BKN050 THIS AFTERNOON. OVC015
WILL RETURN BY AROUND 0300Z. WESTERLY WINDS WILL REACH 10 KT THIS
AFTERNOON WITH GUSTS TO 15KT.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:07 AM PDT FRIDAY...GENERALLY LIGHT WINDS WILL
PREVAIL TODAY BUT ARE EXPECTED TO INCREASE OUT OF THE NORTHWEST
THIS EVENING AS THE SURFACE PRESSURE GRADIENT INCREASES. THE
INCREASING WINDS WILL RESULT IN DETERIORATING SEA CONDITIONS.
WINDS ARE ANTICIPATED TO STAY UP THIS WEEKEND BUT THE FORECAST
CALLS FOR DECREASING WINDS AND IMPROVING SEA CONDITIONS FOR
MEMORIAL DAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 221149
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
449 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 3:20 AM PDT FRIDAY...THE UPPER LEVEL LOW THAT
BROUGHT SOME LIGHT SHOWERS TO THE AREA YESTERDAY HAS NOW MOVED TO
THE SOUTH AND IS CURRENTLY OFF THE SOUTHERN CALIFORNIA COAST. SOME
WRAP-AROUND MOISTURE IS KEEPING SHOWER ACTIVITY GOING IN THE NORTHERN
SIERRA AS WELL AS OVER THE SAN LUIS OBISPO/KERN COUNTY BORDER. A
SLIGHT CHANCE OF LIGHT RAIN SHOWERS IS POSSIBLE AGAIN TODAY OVER
PORTIONS OF THE DISTRICT TODAY...AND INTO THIS EVENING ACROSS THE
FAR EASTERN SECTIONS. HIGHS TODAY ARE EXPECTED TO BE SIMILAR TO
THOSE ON THURSDAY...COOL WITH LOWER 60S AT THE COAST TO THE 70S
INLAND.

THE UPPER LOW IS PROGGED TO MOVE OVER NORTHERN ARIZONA BY LATE
FRIDAY NIGHT...AND SHOWER CHANCES ACROSS OUR DISTRICT WILL
DIMINISH. THERE MAY BE SOME PATCHY COASTAL DRIZZLE SATURDAY
MORNING BUT THAT WILL BE IT.

A SLIGHT WARMING TREND IS INDICATED BEGINNING SATURDAY AND
CONTINUING INTO EARLY NEXT WEEK AS WEAK HIGH PRESSURE BUILDS ALONG
THE COAST. THE MARINE LAYER WILL BECOME EVEN MORE COMPRESSED
ALLOWING AREAS AWAY FROM THE COAST TO WARM BACK UP TO NEAR NORMAL
VALUES. MEDIUM RANGE MODELS INDICATE CONTINUED DRY CONDITIONS
WITH NEAR NORMAL TEMPERATURES THROUGH NEXT WEEK.

&&

.AVIATION...AS OF 4:49 AM PDT FRIDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUDY
CONDITIONS OVER THE TERMINALS TODAY.

VICINITY OF KSFO...MVFR CIGS BKN-OVC025 ARE EXPECTED TO PREVAIL
TODAY. CONDITIONS ARE ANTICIPATED TO BECOME BKN-OVC015 BY AROUND
0300Z. WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CONDITIONS BKN-OVC025 ARE
ANTICIPATED TO IMPROVE TO VFR SCT025 BKN050 THIS AFTERNOON. OVC015
WILL RETURN BY AROUND 0300Z. WESTERLY WINDS WILL REACH 10 KT THIS
AFTERNOON WITH GUSTS TO 15KT.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:07 AM PDT FRIDAY...GENERALLY LIGHT WINDS WILL
PREVAIL TODAY BUT ARE EXPECTED TO INCREASE OUT OF THE NORTHWEST
THIS EVENING AS THE SURFACE PRESSURE GRADIENT INCREASES. THE
INCREASING WINDS WILL RESULT IN DETERIORATING SEA CONDITIONS.
WINDS ARE ANTICIPATED TO STAY UP THIS WEEKEND BUT THE FORECAST
CALLS FOR DECREASING WINDS AND IMPROVING SEA CONDITIONS FOR
MEMORIAL DAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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000
FXUS66 KMTR 221149
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
449 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 3:20 AM PDT FRIDAY...THE UPPER LEVEL LOW THAT
BROUGHT SOME LIGHT SHOWERS TO THE AREA YESTERDAY HAS NOW MOVED TO
THE SOUTH AND IS CURRENTLY OFF THE SOUTHERN CALIFORNIA COAST. SOME
WRAP-AROUND MOISTURE IS KEEPING SHOWER ACTIVITY GOING IN THE NORTHERN
SIERRA AS WELL AS OVER THE SAN LUIS OBISPO/KERN COUNTY BORDER. A
SLIGHT CHANCE OF LIGHT RAIN SHOWERS IS POSSIBLE AGAIN TODAY OVER
PORTIONS OF THE DISTRICT TODAY...AND INTO THIS EVENING ACROSS THE
FAR EASTERN SECTIONS. HIGHS TODAY ARE EXPECTED TO BE SIMILAR TO
THOSE ON THURSDAY...COOL WITH LOWER 60S AT THE COAST TO THE 70S
INLAND.

THE UPPER LOW IS PROGGED TO MOVE OVER NORTHERN ARIZONA BY LATE
FRIDAY NIGHT...AND SHOWER CHANCES ACROSS OUR DISTRICT WILL
DIMINISH. THERE MAY BE SOME PATCHY COASTAL DRIZZLE SATURDAY
MORNING BUT THAT WILL BE IT.

A SLIGHT WARMING TREND IS INDICATED BEGINNING SATURDAY AND
CONTINUING INTO EARLY NEXT WEEK AS WEAK HIGH PRESSURE BUILDS ALONG
THE COAST. THE MARINE LAYER WILL BECOME EVEN MORE COMPRESSED
ALLOWING AREAS AWAY FROM THE COAST TO WARM BACK UP TO NEAR NORMAL
VALUES. MEDIUM RANGE MODELS INDICATE CONTINUED DRY CONDITIONS
WITH NEAR NORMAL TEMPERATURES THROUGH NEXT WEEK.

&&

.AVIATION...AS OF 4:49 AM PDT FRIDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUDY
CONDITIONS OVER THE TERMINALS TODAY.

VICINITY OF KSFO...MVFR CIGS BKN-OVC025 ARE EXPECTED TO PREVAIL
TODAY. CONDITIONS ARE ANTICIPATED TO BECOME BKN-OVC015 BY AROUND
0300Z. WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CONDITIONS BKN-OVC025 ARE
ANTICIPATED TO IMPROVE TO VFR SCT025 BKN050 THIS AFTERNOON. OVC015
WILL RETURN BY AROUND 0300Z. WESTERLY WINDS WILL REACH 10 KT THIS
AFTERNOON WITH GUSTS TO 15KT.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:07 AM PDT FRIDAY...GENERALLY LIGHT WINDS WILL
PREVAIL TODAY BUT ARE EXPECTED TO INCREASE OUT OF THE NORTHWEST
THIS EVENING AS THE SURFACE PRESSURE GRADIENT INCREASES. THE
INCREASING WINDS WILL RESULT IN DETERIORATING SEA CONDITIONS.
WINDS ARE ANTICIPATED TO STAY UP THIS WEEKEND BUT THE FORECAST
CALLS FOR DECREASING WINDS AND IMPROVING SEA CONDITIONS FOR
MEMORIAL DAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

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000
FXUS66 KMTR 221020
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
320 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 3:20 AM PDT FRIDAY...THE UPPER LEVEL LOW THAT
BROUGHT SOME LIGHT SHOWERS TO THE AREA YESTERDAY HAS NOW MOVED TO
THE SOUTH AND IS CURRENTLY OFF THE SOUTHERN CALIFORNIA COAST. SOME
WRAP-AROUND MOISTURE IS KEEPING SHOWER ACTIVITY GOING IN THE NORTHERN
SIERRA AS WELL AS OVER THE SAN LUIS OBISPO/KERN COUNTY BORDER. A
SLIGHT CHANCE OF LIGHT RAIN SHOWERS IS POSSIBLE AGAIN TODAY OVER
PORTIONS OF THE DISTRICT TODAY...AND INTO THIS EVENING ACROSS THE
FAR EASTERN SECTIONS. HIGHS TODAY ARE EXPECTED TO BE SIMILAR TO
THOSE ON THURSDAY...COOL WITH LOWER 60S AT THE COAST TO THE 70S
INLAND.

THE UPPER LOW IS PROGGED TO MOVE OVER NORTHERN ARIZONA BY LATE
FRIDAY NIGHT...AND SHOWER CHANCES ACROSS OUR DISTRICT WILL
DIMINISH. THERE MAY BE SOME PATCHY COASTAL DRIZZLE SATURDAY
MORNING BUT THAT WILL BE IT.

A SLIGHT WARMING TREND IS INDICATED BEGINNING SATURDAY AND
CONTINUING INTO EARLY NEXT WEEK AS WEAK HIGH PRESSURE BUILDS ALONG
THE COAST. THE MARINE LAYER WILL BECOME EVEN MORE COMPRESSED
ALLOWING AREAS AWAY FROM THE COAST TO WARM BACK UP TO NEAR NORMAL
VALUES. MEDIUM RANGE MODELS INDICATE CONTINUED DRY CONDITIONS
WITH NEAR NORMAL TEMPERATURES THROUGH NEXT WEEK.

&&

.AVIATION...AS OF 9:00 PM PDT THURSDAY...THERE WAS LOCAL CLEARING
OF THE LOW CLOUDS AROUND SFO EARLY THIS EVENING BUT CLOUDS ARE
EXPECTED TO FILL BACK IN OVERNIGHT AS A DEEP MOIST LAYER IS OVER
THE AREA. CIGS WILL STAY THROUGH A GOOD PART OF THE DAY FRIDAY AS
AN UPPER LEVEL LOW MOVES INLAND OVER SOUTHERN CALIFORNIA.

VICINITY OF KSFO...MVFR CIGS WITH POSSIBLE CLEARING LATE FRIDAY AFTERNOON.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH FRIDAY. POSSIBLE
CLEARING LATE FRIDAY AFTERNOON.

&&

.MARINE...AS OF 02:07 AM PDT FRIDAY...GENERALLY LIGHT WINDS WILL
PREVAIL TODAY BUT ARE EXPECTED TO INCREASE OUT OF THE NORTHWEST
THIS EVENING AS THE SURFACE PRESSURE GRADIENT INCREASES. THE
INCREASING WINDS WILL RESULT IN DETERIORATING SEA CONDITIONS.
WINDS ARE ANTICIPATED TO STAY UP THIS WEEKEND BUT THE FORECAST
CALLS FOR DECREASING WINDS AND IMPROVING SEA CONDITIONS FOR
MEMORIAL DAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: W PI
MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSBAYAREA
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000
FXUS66 KMTR 221020
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
320 AM PDT FRI MAY 22 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 3:20 AM PDT FRIDAY...THE UPPER LEVEL LOW THAT
BROUGHT SOME LIGHT SHOWERS TO THE AREA YESTERDAY HAS NOW MOVED TO
THE SOUTH AND IS CURRENTLY OFF THE SOUTHERN CALIFORNIA COAST. SOME
WRAP-AROUND MOISTURE IS KEEPING SHOWER ACTIVITY GOING IN THE NORTHERN
SIERRA AS WELL AS OVER THE SAN LUIS OBISPO/KERN COUNTY BORDER. A
SLIGHT CHANCE OF LIGHT RAIN SHOWERS IS POSSIBLE AGAIN TODAY OVER
PORTIONS OF THE DISTRICT TODAY...AND INTO THIS EVENING ACROSS THE
FAR EASTERN SECTIONS. HIGHS TODAY ARE EXPECTED TO BE SIMILAR TO
THOSE ON THURSDAY...COOL WITH LOWER 60S AT THE COAST TO THE 70S
INLAND.

THE UPPER LOW IS PROGGED TO MOVE OVER NORTHERN ARIZONA BY LATE
FRIDAY NIGHT...AND SHOWER CHANCES ACROSS OUR DISTRICT WILL
DIMINISH. THERE MAY BE SOME PATCHY COASTAL DRIZZLE SATURDAY
MORNING BUT THAT WILL BE IT.

A SLIGHT WARMING TREND IS INDICATED BEGINNING SATURDAY AND
CONTINUING INTO EARLY NEXT WEEK AS WEAK HIGH PRESSURE BUILDS ALONG
THE COAST. THE MARINE LAYER WILL BECOME EVEN MORE COMPRESSED
ALLOWING AREAS AWAY FROM THE COAST TO WARM BACK UP TO NEAR NORMAL
VALUES. MEDIUM RANGE MODELS INDICATE CONTINUED DRY CONDITIONS
WITH NEAR NORMAL TEMPERATURES THROUGH NEXT WEEK.

&&

.AVIATION...AS OF 9:00 PM PDT THURSDAY...THERE WAS LOCAL CLEARING
OF THE LOW CLOUDS AROUND SFO EARLY THIS EVENING BUT CLOUDS ARE
EXPECTED TO FILL BACK IN OVERNIGHT AS A DEEP MOIST LAYER IS OVER
THE AREA. CIGS WILL STAY THROUGH A GOOD PART OF THE DAY FRIDAY AS
AN UPPER LEVEL LOW MOVES INLAND OVER SOUTHERN CALIFORNIA.

VICINITY OF KSFO...MVFR CIGS WITH POSSIBLE CLEARING LATE FRIDAY AFTERNOON.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH FRIDAY. POSSIBLE
CLEARING LATE FRIDAY AFTERNOON.

&&

.MARINE...AS OF 02:07 AM PDT FRIDAY...GENERALLY LIGHT WINDS WILL
PREVAIL TODAY BUT ARE EXPECTED TO INCREASE OUT OF THE NORTHWEST
THIS EVENING AS THE SURFACE PRESSURE GRADIENT INCREASES. THE
INCREASING WINDS WILL RESULT IN DETERIORATING SEA CONDITIONS.
WINDS ARE ANTICIPATED TO STAY UP THIS WEEKEND BUT THE FORECAST
CALLS FOR DECREASING WINDS AND IMPROVING SEA CONDITIONS FOR
MEMORIAL DAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM FROM 5 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 7 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: W PI
MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
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000
FXUS66 KMTR 220402
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
902 PM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 9:00 PM PDT THURSDAY...UPPER LEVEL LOW JUST
WEST OF THE BIG SUR COAST IS MOVING SOUTHEAST TOWARDS SOUTHERN
CALIFORNIA. THIS LOW LIFTED THE MARINE LAYER ENOUGH TO SQUEEZE OUT
SOME LIGHT SHOWERS AROUND THE SFO BAY AREA AND NEAR THE COAST.
MOST RAINFALL AMOUNTS WERE UNDER ONE-TENTH OF AN INCH EXCEPT THERE
WAS MORE IN THE SANTA CRUZ MOUNTAINS WITH BEN LOMOND PICKING UP
.22 INCHES. A FEW CONVECTIVE SHOWERS POPPED UP THIS AFTERNOON EAST
OF MT HAMILTON AND IN THE SOUTHERN SAN BENITO COUNTY MOUNTAINS.
PRECIPITATION HAS ENDED FOR NOW. INLAND AREAS WERE ONCE AGAIN
ABOUT 5 DEGREES BELOW NORMAL AND SIMILAR TEMPERATURES ARE EXPECTED
FRIDAY.

LATEST OAK SOUNDING SHOWS MOIST LAYER EXTENDS UP TO 6000 FEET.
THIS WILL PRODUCE PARTLY TO MOSTLY CLOUDY SKIES WITH AREAS OF
DRIZZLE OR LIGHT SHOWERS IN THE COASTAL AREAS LATER TONIGHT AND
FRIDAY MORNING. ALSO THERE WILL BE A SLIGHT CHANCE FOR CONVECTIVE
SHOWERS IN THE INTERIOR MOUNTAINS ESPECIALLY IN SAN BENITO COUNTY
ON FRIDAY.

THE UPPER LOW MOVES INTO SOUTHERN NEVADA ON FRIDAY WITH DRIER
NORTHWESTERLY FLOW SETTLING OVER THE AREA BEHIND THE LOW. THE
MARINE LAYER WILL COMPRESS WHICH COULD PRODUCE PATCHY DRIZZLE
FRIDAY NIGHT AND SATURDAY MORNING.

SATURDAY WILL BE SLIGHTLY WARMER AS AN INSIDE SLIDER WILL TRACK
SOUTH ALONG THE SIERRA NEVADA WITH MUCH DRIER AIR ALOFT SETTLING
OVER THE AREA SATURDAY NIGHT THROUGH MONDAY. THE MARINE LAYER WILL
BECOME EVEN MORE COMPRESSED ALLOWING AREAS AWAY FROM THE COAST TO
WARM BACK UP TO NEAR NORMAL VALUES. LONGER RANGE CALLS FOR
CONTINUED DRY CONDITIONS WITH NEAR NORMAL TEMPERATURES THROUGH
NEXT WEEK.

&&

.AVIATION...AS OF 9:00 PM PDT THURSDAY...THERE WAS LOCAL CLEARING
OF THE LOW CLOUDS AROUND SFO EARLY THIS EVENING BUT CLOUDS ARE
EXPECTED TO FILL BACK IN OVERNIGHT AS A DEEP MOIST LAYER IS OVER
THE AREA. CIGS WILL STAY THROUGH A GOOD PART OF THE DAY FRIDAY AS
AN UPPER LEVEL LOW MOVES INLAND OVER SOUTHERN CALIFORNIA.

VICINITY OF KSFO...MVFR CIGS WITH POSSIBLE CLEARING LATE FRIDAY AFTERNOON.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH FRIDAY. POSSIBLE
CLEARING LATE FRIDAY AFTERNOON.

&&

.MARINE...AS OF 9:00 PM PDT THURSDAY...A WEAK STORM SYSTEM WILL
SLIDE TO THE SOUTHEAST TONIGHT INTO FRIDAY WITH GENERALLY LIGHT
NORTHWESTERLY WINDS EXPECTED. NORTHERLY WINDS WILL INCREASE BEHIND
THE DEPARTING STORM SYSTEM FRIDAY EVENING AS THE SURFACE PRESSURE
GRADIENT STRENGTHENS. THE INCREASING WINDS WILL RESULT IN
DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

&&

$$

PUBLIC FORECAST: W PI
AVIATION/MARINE: W PI

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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000
FXUS66 KMTR 220402
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
902 PM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH FRIDAY. SLIGHT WARMING CAN BE EXPECTED OVER THE
WEEKEND AS THE LOW MOVES OUT OF THE AREA.

&&

.DISCUSSION...AS OF 9:00 PM PDT THURSDAY...UPPER LEVEL LOW JUST
WEST OF THE BIG SUR COAST IS MOVING SOUTHEAST TOWARDS SOUTHERN
CALIFORNIA. THIS LOW LIFTED THE MARINE LAYER ENOUGH TO SQUEEZE OUT
SOME LIGHT SHOWERS AROUND THE SFO BAY AREA AND NEAR THE COAST.
MOST RAINFALL AMOUNTS WERE UNDER ONE-TENTH OF AN INCH EXCEPT THERE
WAS MORE IN THE SANTA CRUZ MOUNTAINS WITH BEN LOMOND PICKING UP
.22 INCHES. A FEW CONVECTIVE SHOWERS POPPED UP THIS AFTERNOON EAST
OF MT HAMILTON AND IN THE SOUTHERN SAN BENITO COUNTY MOUNTAINS.
PRECIPITATION HAS ENDED FOR NOW. INLAND AREAS WERE ONCE AGAIN
ABOUT 5 DEGREES BELOW NORMAL AND SIMILAR TEMPERATURES ARE EXPECTED
FRIDAY.

LATEST OAK SOUNDING SHOWS MOIST LAYER EXTENDS UP TO 6000 FEET.
THIS WILL PRODUCE PARTLY TO MOSTLY CLOUDY SKIES WITH AREAS OF
DRIZZLE OR LIGHT SHOWERS IN THE COASTAL AREAS LATER TONIGHT AND
FRIDAY MORNING. ALSO THERE WILL BE A SLIGHT CHANCE FOR CONVECTIVE
SHOWERS IN THE INTERIOR MOUNTAINS ESPECIALLY IN SAN BENITO COUNTY
ON FRIDAY.

THE UPPER LOW MOVES INTO SOUTHERN NEVADA ON FRIDAY WITH DRIER
NORTHWESTERLY FLOW SETTLING OVER THE AREA BEHIND THE LOW. THE
MARINE LAYER WILL COMPRESS WHICH COULD PRODUCE PATCHY DRIZZLE
FRIDAY NIGHT AND SATURDAY MORNING.

SATURDAY WILL BE SLIGHTLY WARMER AS AN INSIDE SLIDER WILL TRACK
SOUTH ALONG THE SIERRA NEVADA WITH MUCH DRIER AIR ALOFT SETTLING
OVER THE AREA SATURDAY NIGHT THROUGH MONDAY. THE MARINE LAYER WILL
BECOME EVEN MORE COMPRESSED ALLOWING AREAS AWAY FROM THE COAST TO
WARM BACK UP TO NEAR NORMAL VALUES. LONGER RANGE CALLS FOR
CONTINUED DRY CONDITIONS WITH NEAR NORMAL TEMPERATURES THROUGH
NEXT WEEK.

&&

.AVIATION...AS OF 9:00 PM PDT THURSDAY...THERE WAS LOCAL CLEARING
OF THE LOW CLOUDS AROUND SFO EARLY THIS EVENING BUT CLOUDS ARE
EXPECTED TO FILL BACK IN OVERNIGHT AS A DEEP MOIST LAYER IS OVER
THE AREA. CIGS WILL STAY THROUGH A GOOD PART OF THE DAY FRIDAY AS
AN UPPER LEVEL LOW MOVES INLAND OVER SOUTHERN CALIFORNIA.

VICINITY OF KSFO...MVFR CIGS WITH POSSIBLE CLEARING LATE FRIDAY AFTERNOON.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH FRIDAY. POSSIBLE
CLEARING LATE FRIDAY AFTERNOON.

&&

.MARINE...AS OF 9:00 PM PDT THURSDAY...A WEAK STORM SYSTEM WILL
SLIDE TO THE SOUTHEAST TONIGHT INTO FRIDAY WITH GENERALLY LIGHT
NORTHWESTERLY WINDS EXPECTED. NORTHERLY WINDS WILL INCREASE BEHIND
THE DEPARTING STORM SYSTEM FRIDAY EVENING AS THE SURFACE PRESSURE
GRADIENT STRENGTHENS. THE INCREASING WINDS WILL RESULT IN
DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

&&

$$

PUBLIC FORECAST: W PI
AVIATION/MARINE: W PI

VISIT US AT WEATHER.GOV/SANFRANCISCO

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000
FXUS66 KMTR 212335
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
435 PM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 02:40 PM PDT THURSDAY...UNSETTLED WEATHER
PATTERNS IN THE SHORT TERM...BUT WARMER AND DRIER WEATHER FOR THE
HOLIDAY WEEKEND.

A MIX OF SUN AND CLOUDS BLANKET THE BAY AREA THIS AFTERNOON. IT
SHOULD ALSO BE NOTED THAT SCATTERED SHOWERS CONTINUE TO IMPACT
PARTS OF THE BAY AREA THIS AFTERNOON AS WELL. A QUICK LOOK AT THE
KMUX RADAR IMAGERY SHOWS RATHER PERSISTENT SHOWER ACTIVITY OVER
THE SANTA CRUZ MTS. BEN LOMOND MT RAWS MEASURED 0.22 INCHES SINCE
THIS MORNING. THERE HAVE ALSO BEEN A FEW TIPS OF THE BUCKET IN
WESTERN SANTA CLARA COUNTY AND THE HIGHER TERRAIN OF MONTEREY
COUNTY THE PAST FEW HOURS. THE SHOWER ACTIVITY IS A RESULT OF A
PASSING/STRENGTHENING UPPER LOW OFF THE CENTRAL COAST. THIS UPPER
LOW WILL BE THE MAIN PRECIP MAKER THIS EVENING THROUGH FRIDAY.

FOR THE REST OF THE DAY...DAYTIME HEATING COMBINE WITH THE UPPER
LOW WILL KEEP SHOWER ACTIVITY GOING. BEST CHC CONTINUES TO BE OVER
TERRAIN FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE A
FEW HUNDREDTHS UP TO A TENTH OR TWO. HAVE NOT SEEN MUCH IN THE WAY
OF LIGHTNING NEAR OUR CWA. HOWEVER...WILL KEEP A MENTION OF
THUNDER OVER THE SOUTHERN GABILAN RANGE WHERE BUILDS ARE GREATEST
ON RADAR AND SATELLITE.

EXPECT ACTIVITY TO DIMINISH AFTER SUNSET...BUT ENOUGH LIFT REMAINS
AS THE UPPER LOW SWINGS INTO SOCAL LATE TONIGHT/EARLY FRIDAY TO
WARRANT A MENTION OF SHOWERS. SCATTERED SHOWERS WILL ONCE AGAIN BE
POSSIBLE ON FRIDAY AS THE UPPER LOW BEGINS TO EJECT INLAND TOWARD
VEGAS. MUCH OF THE REGION REMAINS UNDER MOIST CYCLONIC FLOW.
SIMILAR TO TODAY...BEST CHANCE FOR PRECIP WILL BE OVER TERRAIN
FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE ON THE LIGHT SIDE.

AS WE HEAD INTO THE HOLIDAY WEEKEND...THE UPPER LOW IS NOW EAST
AND HIGH PRESSURE BUILDS IN FROM THE WEST. THIS PATTERN
DEVELOPMENT IS MORE REMINISCENT OF SUMMER. THAT BEING
SAID...PATCHY DRIZZLE WILL BE POSSIBLE SATURDAY MORNING AS THE
MARINE LAYER COMPRESSES. THE UPSHOT WILL BE EARLIER CLEARING OF
CLOUDS. LATEST FORECAST WILL HAVE AN OVERALL WARMING AND DRYING
TREND THROUGH NEXT WEEKEND. DESPITE THE WARMING TREND...THE
FORECAST WILL STILL CALL FOR TEMPERATURES BELOW NORMAL FOR THIS
TIME OF YEAR. HIGHS IN THE 60S NEAR THE COAST AND 70S...POSS LOW
80S INLAND.

&&

.AVIATION...AS OF 3:00 PM PDT THURSDAY...STILL LARGE POCKETS OF
CIGS ACROSS THE AREA AND OVER THE WATER THIS AFTERNOON AND WITH AN
ONSHORE FLOW WOULD EXPECT BKN TO OVC CONDITIONS TO CONTINUE
OVERNIGHT. CIG HEIGHTS WILL GENERALLY BE VFR TO START BUT QUICKLY
DROP TO MVFR AFTER 02Z. POSSIBLE SOME LOCATIONS COULD GO IFR
OVERNIGHT. WESTERLY WINDS WILL DISSIPATE AFTER SUNSET. MODERATE
CONFIDENCE.

VICINITY OF KSFO...MVFR TO POSSIBLE VFR EARLY ON WITH SOLID MVFR
BY 03Z. CIGS HEIGHTS WILL LOWER TO AROUND 015 BY SUNSET AND
CONTINUE OVERNIGHT. POSSIBLE VFR RETURNS BY SATURDAY AFTERNOON.
WINDS OF 250 TO 270 WILL GENERALLY STAY 10 TO 15 KT THROUGH THE
PERIOD. MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR TO START WITH MVFR CONDITIONS
EXPECTED TO RETURN AFTER 03Z. CIGS MAY BRIEFLY DROP DOWN TO IFR
LEVELS AFTER 06Z. WINDS OF 260 TO 280 OF 8 TO 15 KT WILL DISSIPATE
AFTER SUNSET. MODERATE CONFIDENCE.

&&

.MARINE...AS OF 3:00 PM PDT THURSDAY...A WEAK STORM SYSTEM WILL
SLIDE TO THE SOUTHEAST TONIGHT INTO FRIDAY WITH GENERALLY LIGHT
NORTHWESTERLY WINDS EXPECTED. NORTHERLY WINDS WILL INCREASE BEHIND
THE DEPARTING STORM SYSTEM FRIDAY EVENING AS THE SURFACE PRESSURE
GRADIENT STRENGTHENS. THE INCREASING WINDS WILL RESULT IN
DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: BELL

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 212335
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
435 PM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 02:40 PM PDT THURSDAY...UNSETTLED WEATHER
PATTERNS IN THE SHORT TERM...BUT WARMER AND DRIER WEATHER FOR THE
HOLIDAY WEEKEND.

A MIX OF SUN AND CLOUDS BLANKET THE BAY AREA THIS AFTERNOON. IT
SHOULD ALSO BE NOTED THAT SCATTERED SHOWERS CONTINUE TO IMPACT
PARTS OF THE BAY AREA THIS AFTERNOON AS WELL. A QUICK LOOK AT THE
KMUX RADAR IMAGERY SHOWS RATHER PERSISTENT SHOWER ACTIVITY OVER
THE SANTA CRUZ MTS. BEN LOMOND MT RAWS MEASURED 0.22 INCHES SINCE
THIS MORNING. THERE HAVE ALSO BEEN A FEW TIPS OF THE BUCKET IN
WESTERN SANTA CLARA COUNTY AND THE HIGHER TERRAIN OF MONTEREY
COUNTY THE PAST FEW HOURS. THE SHOWER ACTIVITY IS A RESULT OF A
PASSING/STRENGTHENING UPPER LOW OFF THE CENTRAL COAST. THIS UPPER
LOW WILL BE THE MAIN PRECIP MAKER THIS EVENING THROUGH FRIDAY.

FOR THE REST OF THE DAY...DAYTIME HEATING COMBINE WITH THE UPPER
LOW WILL KEEP SHOWER ACTIVITY GOING. BEST CHC CONTINUES TO BE OVER
TERRAIN FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE A
FEW HUNDREDTHS UP TO A TENTH OR TWO. HAVE NOT SEEN MUCH IN THE WAY
OF LIGHTNING NEAR OUR CWA. HOWEVER...WILL KEEP A MENTION OF
THUNDER OVER THE SOUTHERN GABILAN RANGE WHERE BUILDS ARE GREATEST
ON RADAR AND SATELLITE.

EXPECT ACTIVITY TO DIMINISH AFTER SUNSET...BUT ENOUGH LIFT REMAINS
AS THE UPPER LOW SWINGS INTO SOCAL LATE TONIGHT/EARLY FRIDAY TO
WARRANT A MENTION OF SHOWERS. SCATTERED SHOWERS WILL ONCE AGAIN BE
POSSIBLE ON FRIDAY AS THE UPPER LOW BEGINS TO EJECT INLAND TOWARD
VEGAS. MUCH OF THE REGION REMAINS UNDER MOIST CYCLONIC FLOW.
SIMILAR TO TODAY...BEST CHANCE FOR PRECIP WILL BE OVER TERRAIN
FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE ON THE LIGHT SIDE.

AS WE HEAD INTO THE HOLIDAY WEEKEND...THE UPPER LOW IS NOW EAST
AND HIGH PRESSURE BUILDS IN FROM THE WEST. THIS PATTERN
DEVELOPMENT IS MORE REMINISCENT OF SUMMER. THAT BEING
SAID...PATCHY DRIZZLE WILL BE POSSIBLE SATURDAY MORNING AS THE
MARINE LAYER COMPRESSES. THE UPSHOT WILL BE EARLIER CLEARING OF
CLOUDS. LATEST FORECAST WILL HAVE AN OVERALL WARMING AND DRYING
TREND THROUGH NEXT WEEKEND. DESPITE THE WARMING TREND...THE
FORECAST WILL STILL CALL FOR TEMPERATURES BELOW NORMAL FOR THIS
TIME OF YEAR. HIGHS IN THE 60S NEAR THE COAST AND 70S...POSS LOW
80S INLAND.

&&

.AVIATION...AS OF 3:00 PM PDT THURSDAY...STILL LARGE POCKETS OF
CIGS ACROSS THE AREA AND OVER THE WATER THIS AFTERNOON AND WITH AN
ONSHORE FLOW WOULD EXPECT BKN TO OVC CONDITIONS TO CONTINUE
OVERNIGHT. CIG HEIGHTS WILL GENERALLY BE VFR TO START BUT QUICKLY
DROP TO MVFR AFTER 02Z. POSSIBLE SOME LOCATIONS COULD GO IFR
OVERNIGHT. WESTERLY WINDS WILL DISSIPATE AFTER SUNSET. MODERATE
CONFIDENCE.

VICINITY OF KSFO...MVFR TO POSSIBLE VFR EARLY ON WITH SOLID MVFR
BY 03Z. CIGS HEIGHTS WILL LOWER TO AROUND 015 BY SUNSET AND
CONTINUE OVERNIGHT. POSSIBLE VFR RETURNS BY SATURDAY AFTERNOON.
WINDS OF 250 TO 270 WILL GENERALLY STAY 10 TO 15 KT THROUGH THE
PERIOD. MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR TO START WITH MVFR CONDITIONS
EXPECTED TO RETURN AFTER 03Z. CIGS MAY BRIEFLY DROP DOWN TO IFR
LEVELS AFTER 06Z. WINDS OF 260 TO 280 OF 8 TO 15 KT WILL DISSIPATE
AFTER SUNSET. MODERATE CONFIDENCE.

&&

.MARINE...AS OF 3:00 PM PDT THURSDAY...A WEAK STORM SYSTEM WILL
SLIDE TO THE SOUTHEAST TONIGHT INTO FRIDAY WITH GENERALLY LIGHT
NORTHWESTERLY WINDS EXPECTED. NORTHERLY WINDS WILL INCREASE BEHIND
THE DEPARTING STORM SYSTEM FRIDAY EVENING AS THE SURFACE PRESSURE
GRADIENT STRENGTHENS. THE INCREASING WINDS WILL RESULT IN
DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: BELL

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 212335
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
435 PM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 02:40 PM PDT THURSDAY...UNSETTLED WEATHER
PATTERNS IN THE SHORT TERM...BUT WARMER AND DRIER WEATHER FOR THE
HOLIDAY WEEKEND.

A MIX OF SUN AND CLOUDS BLANKET THE BAY AREA THIS AFTERNOON. IT
SHOULD ALSO BE NOTED THAT SCATTERED SHOWERS CONTINUE TO IMPACT
PARTS OF THE BAY AREA THIS AFTERNOON AS WELL. A QUICK LOOK AT THE
KMUX RADAR IMAGERY SHOWS RATHER PERSISTENT SHOWER ACTIVITY OVER
THE SANTA CRUZ MTS. BEN LOMOND MT RAWS MEASURED 0.22 INCHES SINCE
THIS MORNING. THERE HAVE ALSO BEEN A FEW TIPS OF THE BUCKET IN
WESTERN SANTA CLARA COUNTY AND THE HIGHER TERRAIN OF MONTEREY
COUNTY THE PAST FEW HOURS. THE SHOWER ACTIVITY IS A RESULT OF A
PASSING/STRENGTHENING UPPER LOW OFF THE CENTRAL COAST. THIS UPPER
LOW WILL BE THE MAIN PRECIP MAKER THIS EVENING THROUGH FRIDAY.

FOR THE REST OF THE DAY...DAYTIME HEATING COMBINE WITH THE UPPER
LOW WILL KEEP SHOWER ACTIVITY GOING. BEST CHC CONTINUES TO BE OVER
TERRAIN FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE A
FEW HUNDREDTHS UP TO A TENTH OR TWO. HAVE NOT SEEN MUCH IN THE WAY
OF LIGHTNING NEAR OUR CWA. HOWEVER...WILL KEEP A MENTION OF
THUNDER OVER THE SOUTHERN GABILAN RANGE WHERE BUILDS ARE GREATEST
ON RADAR AND SATELLITE.

EXPECT ACTIVITY TO DIMINISH AFTER SUNSET...BUT ENOUGH LIFT REMAINS
AS THE UPPER LOW SWINGS INTO SOCAL LATE TONIGHT/EARLY FRIDAY TO
WARRANT A MENTION OF SHOWERS. SCATTERED SHOWERS WILL ONCE AGAIN BE
POSSIBLE ON FRIDAY AS THE UPPER LOW BEGINS TO EJECT INLAND TOWARD
VEGAS. MUCH OF THE REGION REMAINS UNDER MOIST CYCLONIC FLOW.
SIMILAR TO TODAY...BEST CHANCE FOR PRECIP WILL BE OVER TERRAIN
FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE ON THE LIGHT SIDE.

AS WE HEAD INTO THE HOLIDAY WEEKEND...THE UPPER LOW IS NOW EAST
AND HIGH PRESSURE BUILDS IN FROM THE WEST. THIS PATTERN
DEVELOPMENT IS MORE REMINISCENT OF SUMMER. THAT BEING
SAID...PATCHY DRIZZLE WILL BE POSSIBLE SATURDAY MORNING AS THE
MARINE LAYER COMPRESSES. THE UPSHOT WILL BE EARLIER CLEARING OF
CLOUDS. LATEST FORECAST WILL HAVE AN OVERALL WARMING AND DRYING
TREND THROUGH NEXT WEEKEND. DESPITE THE WARMING TREND...THE
FORECAST WILL STILL CALL FOR TEMPERATURES BELOW NORMAL FOR THIS
TIME OF YEAR. HIGHS IN THE 60S NEAR THE COAST AND 70S...POSS LOW
80S INLAND.

&&

.AVIATION...AS OF 3:00 PM PDT THURSDAY...STILL LARGE POCKETS OF
CIGS ACROSS THE AREA AND OVER THE WATER THIS AFTERNOON AND WITH AN
ONSHORE FLOW WOULD EXPECT BKN TO OVC CONDITIONS TO CONTINUE
OVERNIGHT. CIG HEIGHTS WILL GENERALLY BE VFR TO START BUT QUICKLY
DROP TO MVFR AFTER 02Z. POSSIBLE SOME LOCATIONS COULD GO IFR
OVERNIGHT. WESTERLY WINDS WILL DISSIPATE AFTER SUNSET. MODERATE
CONFIDENCE.

VICINITY OF KSFO...MVFR TO POSSIBLE VFR EARLY ON WITH SOLID MVFR
BY 03Z. CIGS HEIGHTS WILL LOWER TO AROUND 015 BY SUNSET AND
CONTINUE OVERNIGHT. POSSIBLE VFR RETURNS BY SATURDAY AFTERNOON.
WINDS OF 250 TO 270 WILL GENERALLY STAY 10 TO 15 KT THROUGH THE
PERIOD. MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR TO START WITH MVFR CONDITIONS
EXPECTED TO RETURN AFTER 03Z. CIGS MAY BRIEFLY DROP DOWN TO IFR
LEVELS AFTER 06Z. WINDS OF 260 TO 280 OF 8 TO 15 KT WILL DISSIPATE
AFTER SUNSET. MODERATE CONFIDENCE.

&&

.MARINE...AS OF 3:00 PM PDT THURSDAY...A WEAK STORM SYSTEM WILL
SLIDE TO THE SOUTHEAST TONIGHT INTO FRIDAY WITH GENERALLY LIGHT
NORTHWESTERLY WINDS EXPECTED. NORTHERLY WINDS WILL INCREASE BEHIND
THE DEPARTING STORM SYSTEM FRIDAY EVENING AS THE SURFACE PRESSURE
GRADIENT STRENGTHENS. THE INCREASING WINDS WILL RESULT IN
DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: BELL

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 212142
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
242 PM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 02:40 PM PDT THURSDAY...UNSETTLED WEATHER
PATTERNS IN THE SHORT TERM...BUT WARMER AND DRIER WEATHER FOR THE
HOLIDAY WEEKEND.

A MIX OF SUN AND CLOUDS BLANKET THE BAY AREA THIS AFTERNOON. IT
SHOULD ALSO BE NOTED THAT SCATTERED SHOWERS CONTINUE TO IMPACT
PARTS OF THE BAY AREA THIS AFTERNOON AS WELL. A QUICK LOOK AT THE
KMUX RADAR IMAGERY SHOWS RATHER PERSISTENT SHOWER ACTIVITY OVER
THE SANTA CRUZ MTS. BEN LOMOND MT RAWS MEASURED 0.22 INCHES SINCE
THIS MORNING. THERE HAVE ALSO BEEN A FEW TIPS OF THE BUCKET IN
WESTERN SANTA CLARA COUNTY AND THE HIGHER TERRAIN OF MONTEREY
COUNTY THE PAST FEW HOURS. THE SHOWER ACTIVITY IS A RESULT OF A
PASSING/STRENGTHENING UPPER LOW OFF THE CENTRAL COAST. THIS UPPER
LOW WILL BE THE MAIN PRECIP MAKER THIS EVENING THROUGH FRIDAY.

FOR THE REST OF THE DAY...DAYTIME HEATING COMBINE WITH THE UPPER
LOW WILL KEEP SHOWER ACTIVITY GOING. BEST CHC CONTINUES TO BE OVER
TERRAIN FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE A
FEW HUNDREDTHS UP TO A TENTH OR TWO. HAVE NOT SEEN MUCH IN THE WAY
OF LIGHTNING NEAR OUR CWA. HOWEVER...WILL KEEP A MENTION OF
THUNDER OVER THE SOUTHERN GABILAN RANGE WHERE BUILDS ARE GREATEST
ON RADAR AND SATELLITE.

EXPECT ACTIVITY TO DIMINISH AFTER SUNSET...BUT ENOUGH LIFT REMAINS
AS THE UPPER LOW SWINGS INTO SOCAL LATE TONIGHT/EARLY FRIDAY TO
WARRANT A MENTION OF SHOWERS. SCATTERED SHOWERS WILL ONCE AGAIN BE
POSSIBLE ON FRIDAY AS THE UPPER LOW BEGINS TO EJECT INLAND TOWARD
VEGAS. MUCH OF THE REGION REMAINS UNDER MOIST CYCLONIC FLOW.
SIMILAR TO TODAY...BEST CHANCE FOR PRECIP WILL BE OVER TERRAIN
FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE ON THE LIGHT SIDE.

AS WE HEAD INTO THE HOLIDAY WEEKEND...THE UPPER LOW IS NOW EAST
AND HIGH PRESSURE BUILDS IN FROM THE WEST. THIS PATTERN
DEVELOPMENT IS MORE REMINISCENT OF SUMMER. THAT BEING
SAID...PATCHY DRIZZLE WILL BE POSSIBLE SATURDAY MORNING AS THE
MARINE LAYER COMPRESSES. THE UPSHOT WILL BE EARLIER CLEARING OF
CLOUDS. LATEST FORECAST WILL HAVE AN OVERALL WARMING AND DRYING
TREND THROUGH NEXT WEEKEND. DESPITE THE WARMING TREND...THE
FORECAST WILL STILL CALL FOR TEMPERATURES BELOW NORMAL FOR THIS
TIME OF YEAR. HIGHS IN THE 60S NEAR THE COAST AND 70S...POSS LOW
80S INLAND.

&&

.AVIATION...AS OF 11:00 AM PDT THURSDAY...WIDESPREAD CLOUDS TODAY
ALONG WITH A DEEP ALBEIT POORLY DEFINED MARINE LAYER PLUS ONSHORE
SURFACE FLOW WILL KEEPS CIGS GOING IN ALL SPOTS THROUGH THE
PERIOD. DID MAKE SOME ADJUSTMENTS TO THE TAFS FROM THE PREVIOUS
PACKAGE TO KEEP CIGS LOWER IN MOST SPOTS. MVFR GENERALLY EXPECTED
TONIGHT. WINDS SPEEDS MOSTLY UNDER 15 KT EXCEPT AT SFO. A FEW LIGHT
SHOWERS ALSO POSSIBLE THROUGH THE PERIOD. MODERATE CONFIDENCE.

VICINITY OF KSFO...STILL SHOWING BKN015 ON THE 5 MINUTE OB
ALTHOUGH CAMS ARE SHOWING DEFINITE BREAKS AND LIFTING. WIDESPREAD
CLOUDS THROUGH THE AREA ALONG WITH WESTERLY FLOW AT THE SURFACE
SHOULD KEEPS CIGS GOING ALL DAY UNDER 5KFT. WESTERLY WINDS FROM
21Z TO 02Z AROUND 15 KT FROM 260 TO 280. MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR THROUGH THE PERIOD DUE TO
PERSISTENT ONSHORE FLOW PLUS DEEP MARINE LAYER. SPEEDS WILL PICK
UP THROUGH THE DAY WITH WESTERLY VALUES OF 8 TO 12 KT AFTER 20Z.
LOCALLY HIGHER GUSTS TO KSNS POSSIBLE. MODERATE CONFIDENCE.

&&

.MARINE...AS OF 11:00 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: BELL

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 212142
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
242 PM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 02:40 PM PDT THURSDAY...UNSETTLED WEATHER
PATTERNS IN THE SHORT TERM...BUT WARMER AND DRIER WEATHER FOR THE
HOLIDAY WEEKEND.

A MIX OF SUN AND CLOUDS BLANKET THE BAY AREA THIS AFTERNOON. IT
SHOULD ALSO BE NOTED THAT SCATTERED SHOWERS CONTINUE TO IMPACT
PARTS OF THE BAY AREA THIS AFTERNOON AS WELL. A QUICK LOOK AT THE
KMUX RADAR IMAGERY SHOWS RATHER PERSISTENT SHOWER ACTIVITY OVER
THE SANTA CRUZ MTS. BEN LOMOND MT RAWS MEASURED 0.22 INCHES SINCE
THIS MORNING. THERE HAVE ALSO BEEN A FEW TIPS OF THE BUCKET IN
WESTERN SANTA CLARA COUNTY AND THE HIGHER TERRAIN OF MONTEREY
COUNTY THE PAST FEW HOURS. THE SHOWER ACTIVITY IS A RESULT OF A
PASSING/STRENGTHENING UPPER LOW OFF THE CENTRAL COAST. THIS UPPER
LOW WILL BE THE MAIN PRECIP MAKER THIS EVENING THROUGH FRIDAY.

FOR THE REST OF THE DAY...DAYTIME HEATING COMBINE WITH THE UPPER
LOW WILL KEEP SHOWER ACTIVITY GOING. BEST CHC CONTINUES TO BE OVER
TERRAIN FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE A
FEW HUNDREDTHS UP TO A TENTH OR TWO. HAVE NOT SEEN MUCH IN THE WAY
OF LIGHTNING NEAR OUR CWA. HOWEVER...WILL KEEP A MENTION OF
THUNDER OVER THE SOUTHERN GABILAN RANGE WHERE BUILDS ARE GREATEST
ON RADAR AND SATELLITE.

EXPECT ACTIVITY TO DIMINISH AFTER SUNSET...BUT ENOUGH LIFT REMAINS
AS THE UPPER LOW SWINGS INTO SOCAL LATE TONIGHT/EARLY FRIDAY TO
WARRANT A MENTION OF SHOWERS. SCATTERED SHOWERS WILL ONCE AGAIN BE
POSSIBLE ON FRIDAY AS THE UPPER LOW BEGINS TO EJECT INLAND TOWARD
VEGAS. MUCH OF THE REGION REMAINS UNDER MOIST CYCLONIC FLOW.
SIMILAR TO TODAY...BEST CHANCE FOR PRECIP WILL BE OVER TERRAIN
FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE ON THE LIGHT SIDE.

AS WE HEAD INTO THE HOLIDAY WEEKEND...THE UPPER LOW IS NOW EAST
AND HIGH PRESSURE BUILDS IN FROM THE WEST. THIS PATTERN
DEVELOPMENT IS MORE REMINISCENT OF SUMMER. THAT BEING
SAID...PATCHY DRIZZLE WILL BE POSSIBLE SATURDAY MORNING AS THE
MARINE LAYER COMPRESSES. THE UPSHOT WILL BE EARLIER CLEARING OF
CLOUDS. LATEST FORECAST WILL HAVE AN OVERALL WARMING AND DRYING
TREND THROUGH NEXT WEEKEND. DESPITE THE WARMING TREND...THE
FORECAST WILL STILL CALL FOR TEMPERATURES BELOW NORMAL FOR THIS
TIME OF YEAR. HIGHS IN THE 60S NEAR THE COAST AND 70S...POSS LOW
80S INLAND.

&&

.AVIATION...AS OF 11:00 AM PDT THURSDAY...WIDESPREAD CLOUDS TODAY
ALONG WITH A DEEP ALBEIT POORLY DEFINED MARINE LAYER PLUS ONSHORE
SURFACE FLOW WILL KEEPS CIGS GOING IN ALL SPOTS THROUGH THE
PERIOD. DID MAKE SOME ADJUSTMENTS TO THE TAFS FROM THE PREVIOUS
PACKAGE TO KEEP CIGS LOWER IN MOST SPOTS. MVFR GENERALLY EXPECTED
TONIGHT. WINDS SPEEDS MOSTLY UNDER 15 KT EXCEPT AT SFO. A FEW LIGHT
SHOWERS ALSO POSSIBLE THROUGH THE PERIOD. MODERATE CONFIDENCE.

VICINITY OF KSFO...STILL SHOWING BKN015 ON THE 5 MINUTE OB
ALTHOUGH CAMS ARE SHOWING DEFINITE BREAKS AND LIFTING. WIDESPREAD
CLOUDS THROUGH THE AREA ALONG WITH WESTERLY FLOW AT THE SURFACE
SHOULD KEEPS CIGS GOING ALL DAY UNDER 5KFT. WESTERLY WINDS FROM
21Z TO 02Z AROUND 15 KT FROM 260 TO 280. MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR THROUGH THE PERIOD DUE TO
PERSISTENT ONSHORE FLOW PLUS DEEP MARINE LAYER. SPEEDS WILL PICK
UP THROUGH THE DAY WITH WESTERLY VALUES OF 8 TO 12 KT AFTER 20Z.
LOCALLY HIGHER GUSTS TO KSNS POSSIBLE. MODERATE CONFIDENCE.

&&

.MARINE...AS OF 11:00 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: BELL

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA








000
FXUS66 KMTR 212142
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
242 PM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 02:40 PM PDT THURSDAY...UNSETTLED WEATHER
PATTERNS IN THE SHORT TERM...BUT WARMER AND DRIER WEATHER FOR THE
HOLIDAY WEEKEND.

A MIX OF SUN AND CLOUDS BLANKET THE BAY AREA THIS AFTERNOON. IT
SHOULD ALSO BE NOTED THAT SCATTERED SHOWERS CONTINUE TO IMPACT
PARTS OF THE BAY AREA THIS AFTERNOON AS WELL. A QUICK LOOK AT THE
KMUX RADAR IMAGERY SHOWS RATHER PERSISTENT SHOWER ACTIVITY OVER
THE SANTA CRUZ MTS. BEN LOMOND MT RAWS MEASURED 0.22 INCHES SINCE
THIS MORNING. THERE HAVE ALSO BEEN A FEW TIPS OF THE BUCKET IN
WESTERN SANTA CLARA COUNTY AND THE HIGHER TERRAIN OF MONTEREY
COUNTY THE PAST FEW HOURS. THE SHOWER ACTIVITY IS A RESULT OF A
PASSING/STRENGTHENING UPPER LOW OFF THE CENTRAL COAST. THIS UPPER
LOW WILL BE THE MAIN PRECIP MAKER THIS EVENING THROUGH FRIDAY.

FOR THE REST OF THE DAY...DAYTIME HEATING COMBINE WITH THE UPPER
LOW WILL KEEP SHOWER ACTIVITY GOING. BEST CHC CONTINUES TO BE OVER
TERRAIN FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE A
FEW HUNDREDTHS UP TO A TENTH OR TWO. HAVE NOT SEEN MUCH IN THE WAY
OF LIGHTNING NEAR OUR CWA. HOWEVER...WILL KEEP A MENTION OF
THUNDER OVER THE SOUTHERN GABILAN RANGE WHERE BUILDS ARE GREATEST
ON RADAR AND SATELLITE.

EXPECT ACTIVITY TO DIMINISH AFTER SUNSET...BUT ENOUGH LIFT REMAINS
AS THE UPPER LOW SWINGS INTO SOCAL LATE TONIGHT/EARLY FRIDAY TO
WARRANT A MENTION OF SHOWERS. SCATTERED SHOWERS WILL ONCE AGAIN BE
POSSIBLE ON FRIDAY AS THE UPPER LOW BEGINS TO EJECT INLAND TOWARD
VEGAS. MUCH OF THE REGION REMAINS UNDER MOIST CYCLONIC FLOW.
SIMILAR TO TODAY...BEST CHANCE FOR PRECIP WILL BE OVER TERRAIN
FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE ON THE LIGHT SIDE.

AS WE HEAD INTO THE HOLIDAY WEEKEND...THE UPPER LOW IS NOW EAST
AND HIGH PRESSURE BUILDS IN FROM THE WEST. THIS PATTERN
DEVELOPMENT IS MORE REMINISCENT OF SUMMER. THAT BEING
SAID...PATCHY DRIZZLE WILL BE POSSIBLE SATURDAY MORNING AS THE
MARINE LAYER COMPRESSES. THE UPSHOT WILL BE EARLIER CLEARING OF
CLOUDS. LATEST FORECAST WILL HAVE AN OVERALL WARMING AND DRYING
TREND THROUGH NEXT WEEKEND. DESPITE THE WARMING TREND...THE
FORECAST WILL STILL CALL FOR TEMPERATURES BELOW NORMAL FOR THIS
TIME OF YEAR. HIGHS IN THE 60S NEAR THE COAST AND 70S...POSS LOW
80S INLAND.

&&

.AVIATION...AS OF 11:00 AM PDT THURSDAY...WIDESPREAD CLOUDS TODAY
ALONG WITH A DEEP ALBEIT POORLY DEFINED MARINE LAYER PLUS ONSHORE
SURFACE FLOW WILL KEEPS CIGS GOING IN ALL SPOTS THROUGH THE
PERIOD. DID MAKE SOME ADJUSTMENTS TO THE TAFS FROM THE PREVIOUS
PACKAGE TO KEEP CIGS LOWER IN MOST SPOTS. MVFR GENERALLY EXPECTED
TONIGHT. WINDS SPEEDS MOSTLY UNDER 15 KT EXCEPT AT SFO. A FEW LIGHT
SHOWERS ALSO POSSIBLE THROUGH THE PERIOD. MODERATE CONFIDENCE.

VICINITY OF KSFO...STILL SHOWING BKN015 ON THE 5 MINUTE OB
ALTHOUGH CAMS ARE SHOWING DEFINITE BREAKS AND LIFTING. WIDESPREAD
CLOUDS THROUGH THE AREA ALONG WITH WESTERLY FLOW AT THE SURFACE
SHOULD KEEPS CIGS GOING ALL DAY UNDER 5KFT. WESTERLY WINDS FROM
21Z TO 02Z AROUND 15 KT FROM 260 TO 280. MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR THROUGH THE PERIOD DUE TO
PERSISTENT ONSHORE FLOW PLUS DEEP MARINE LAYER. SPEEDS WILL PICK
UP THROUGH THE DAY WITH WESTERLY VALUES OF 8 TO 12 KT AFTER 20Z.
LOCALLY HIGHER GUSTS TO KSNS POSSIBLE. MODERATE CONFIDENCE.

&&

.MARINE...AS OF 11:00 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: BELL

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 212142
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
242 PM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 02:40 PM PDT THURSDAY...UNSETTLED WEATHER
PATTERNS IN THE SHORT TERM...BUT WARMER AND DRIER WEATHER FOR THE
HOLIDAY WEEKEND.

A MIX OF SUN AND CLOUDS BLANKET THE BAY AREA THIS AFTERNOON. IT
SHOULD ALSO BE NOTED THAT SCATTERED SHOWERS CONTINUE TO IMPACT
PARTS OF THE BAY AREA THIS AFTERNOON AS WELL. A QUICK LOOK AT THE
KMUX RADAR IMAGERY SHOWS RATHER PERSISTENT SHOWER ACTIVITY OVER
THE SANTA CRUZ MTS. BEN LOMOND MT RAWS MEASURED 0.22 INCHES SINCE
THIS MORNING. THERE HAVE ALSO BEEN A FEW TIPS OF THE BUCKET IN
WESTERN SANTA CLARA COUNTY AND THE HIGHER TERRAIN OF MONTEREY
COUNTY THE PAST FEW HOURS. THE SHOWER ACTIVITY IS A RESULT OF A
PASSING/STRENGTHENING UPPER LOW OFF THE CENTRAL COAST. THIS UPPER
LOW WILL BE THE MAIN PRECIP MAKER THIS EVENING THROUGH FRIDAY.

FOR THE REST OF THE DAY...DAYTIME HEATING COMBINE WITH THE UPPER
LOW WILL KEEP SHOWER ACTIVITY GOING. BEST CHC CONTINUES TO BE OVER
TERRAIN FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE A
FEW HUNDREDTHS UP TO A TENTH OR TWO. HAVE NOT SEEN MUCH IN THE WAY
OF LIGHTNING NEAR OUR CWA. HOWEVER...WILL KEEP A MENTION OF
THUNDER OVER THE SOUTHERN GABILAN RANGE WHERE BUILDS ARE GREATEST
ON RADAR AND SATELLITE.

EXPECT ACTIVITY TO DIMINISH AFTER SUNSET...BUT ENOUGH LIFT REMAINS
AS THE UPPER LOW SWINGS INTO SOCAL LATE TONIGHT/EARLY FRIDAY TO
WARRANT A MENTION OF SHOWERS. SCATTERED SHOWERS WILL ONCE AGAIN BE
POSSIBLE ON FRIDAY AS THE UPPER LOW BEGINS TO EJECT INLAND TOWARD
VEGAS. MUCH OF THE REGION REMAINS UNDER MOIST CYCLONIC FLOW.
SIMILAR TO TODAY...BEST CHANCE FOR PRECIP WILL BE OVER TERRAIN
FAVORED LOCATIONS. RAINFALL AMOUNTS WILL GENERALLY BE ON THE LIGHT SIDE.

AS WE HEAD INTO THE HOLIDAY WEEKEND...THE UPPER LOW IS NOW EAST
AND HIGH PRESSURE BUILDS IN FROM THE WEST. THIS PATTERN
DEVELOPMENT IS MORE REMINISCENT OF SUMMER. THAT BEING
SAID...PATCHY DRIZZLE WILL BE POSSIBLE SATURDAY MORNING AS THE
MARINE LAYER COMPRESSES. THE UPSHOT WILL BE EARLIER CLEARING OF
CLOUDS. LATEST FORECAST WILL HAVE AN OVERALL WARMING AND DRYING
TREND THROUGH NEXT WEEKEND. DESPITE THE WARMING TREND...THE
FORECAST WILL STILL CALL FOR TEMPERATURES BELOW NORMAL FOR THIS
TIME OF YEAR. HIGHS IN THE 60S NEAR THE COAST AND 70S...POSS LOW
80S INLAND.

&&

.AVIATION...AS OF 11:00 AM PDT THURSDAY...WIDESPREAD CLOUDS TODAY
ALONG WITH A DEEP ALBEIT POORLY DEFINED MARINE LAYER PLUS ONSHORE
SURFACE FLOW WILL KEEPS CIGS GOING IN ALL SPOTS THROUGH THE
PERIOD. DID MAKE SOME ADJUSTMENTS TO THE TAFS FROM THE PREVIOUS
PACKAGE TO KEEP CIGS LOWER IN MOST SPOTS. MVFR GENERALLY EXPECTED
TONIGHT. WINDS SPEEDS MOSTLY UNDER 15 KT EXCEPT AT SFO. A FEW LIGHT
SHOWERS ALSO POSSIBLE THROUGH THE PERIOD. MODERATE CONFIDENCE.

VICINITY OF KSFO...STILL SHOWING BKN015 ON THE 5 MINUTE OB
ALTHOUGH CAMS ARE SHOWING DEFINITE BREAKS AND LIFTING. WIDESPREAD
CLOUDS THROUGH THE AREA ALONG WITH WESTERLY FLOW AT THE SURFACE
SHOULD KEEPS CIGS GOING ALL DAY UNDER 5KFT. WESTERLY WINDS FROM
21Z TO 02Z AROUND 15 KT FROM 260 TO 280. MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR THROUGH THE PERIOD DUE TO
PERSISTENT ONSHORE FLOW PLUS DEEP MARINE LAYER. SPEEDS WILL PICK
UP THROUGH THE DAY WITH WESTERLY VALUES OF 8 TO 12 KT AFTER 20Z.
LOCALLY HIGHER GUSTS TO KSNS POSSIBLE. MODERATE CONFIDENCE.

&&

.MARINE...AS OF 11:00 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: BELL

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA








000
FXUS66 KMTR 211802
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1102 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 08:45 AM PDT THURSDAY...DEEP STRATUS DECK
COVERS MUCH OF THE BAY AREA THIS MORNING...MOSTLY CLOUDY START TO
THE DAY. INTERESTING TO NOTE THE CLOUDS ARE NOT YOUR TYPICAL
MARINE LAYER...SODARS AND PROFILERS DO NOT INDICATE A DEFINED
MARINE LAYER. THE KOAK SOUNDING ON THE OTHER HAND DOES SHOW A
MOIST LOWER 5K FEET. SYNOPTICALLY SPEAKING...A WEAK UPPER LEVEL
DISTURBANCE IS CURRENTLY SITTING OFF THE SF BAY COAST. THE
ASSOCIATED LIFT AND MOIST LOWER 5K FT HELPED TO PRODUCE SOME LIGHT
SHOWERS OVERNIGHT WITH SEVERAL STATIONS MEASURING UP TO A TENTH.

FOR THE REST OF TODAY...ANOTHER STRONGER UPPER LOW IS FORECAST TO
DROP SOUTHWARD THROUGH THE BASE OF A BROAD UPPER TROUGH. THE
UPPER LOW CAN BE SEEN ON THE WATER VAPOR NEAR 130W. LATEST SHORT
TERM MODELS...THE HRRR AND RAP BOTH INDICATE INCREASED SHOWER
ACTIVITY THIS AFTERNOON AS THE UPPER LOW DEEPENS OFF THE COAST.
THE BEST CHANCE FOR SHOWERS WILL BE OVER TERRAIN FAVORED
LOCATIONS. IN FACT...THE LATEST NAM/HRRR INDICATE A LITTLE BIT OF
SFC INSTABILITY OVER THE E BAY HILLS AND THE GABILAN RANGE THIS
AFTERNOON. THEREFORE COULD NOT TOTALLY RULE OUT SOME THUNDER AS WELL.

GIVEN THE UNCERTAINTY OF ACTUAL LOCATIONS FOR SHOWER
ACTIVITY...LATEST FORECAST HAS BLANKET COVERAGE OF SHOWERS THIS
AFTERNOON. NO MAJOR UPDATE IS NEEDED AT THIS TIME...BUT WILL LIKE
TWEAK THE WEATHER GRIDS TO BETTER REFLECT REALITY THIS AFTERNOON.

&&

.PREV DISCUSSION...AS OF 3:58 AM PDT THURSDAY...THE TROUGH AND
UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY WITH
HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE EASTERN
PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND FOR
SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER TROUGH
WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 11:00 AM PDT THURSDAY...WIDESPREAD CLOUDS TODAY
ALONG WITH A DEEP ALBEIT POORLY DEFINED MARINE LAYER PLUS ONSHORE
SURFACE FLOW WILL KEEPS CIGS GOING IN ALL SPOTS THROUGH THE
PERIOD. DID MAKE SOME ADJUSTMENTS TO THE TAFS FROM THE PREVIOUS
PACKAGE TO KEEP CIGS LOWER IN MOST SPOTS. MVFR GENERALLY EXPECTED
TONIGHT. WINDS SPEEDS MOSTLY UNDER 15 KT EXCEPT AT SFO. A FEW LIGHT
SHOWERS ALSO POSSIBLE THROUGH THE PERIOD. MODERATE CONFIDENCE.

VICINITY OF KSFO...STILL SHOWING BKN015 ON THE 5 MINUTE OB
ALTHOUGH CAMS ARE SHOWING DEFINITE BREAKS AND LIFTING. WIDESPREAD
CLOUDS THROUGH THE AREA ALONG WITH WESTERLY FLOW AT THE SURFACE
SHOULD KEEPS CIGS GOING ALL DAY UNDER 5KFT. WESTERLY WINDS FROM
21Z TO 02Z AROUND 15 KT FROM 260 TO 280. MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR THROUGH THE PERIOD DUE TO
PERSISTENT ONSHORE FLOW PLUS DEEP MARINE LAYER. SPEEDS WILL PICK
UP THROUGH THE DAY WITH WESTERLY VALUES OF 8 TO 12 KT AFTER 20Z.
LOCALLY HIGHER GUSTS TO KSNS POSSIBLE. MODERATE CONFIDENCE.

&&

.MARINE...AS OF 11:00 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: BELL

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 211802
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1102 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 08:45 AM PDT THURSDAY...DEEP STRATUS DECK
COVERS MUCH OF THE BAY AREA THIS MORNING...MOSTLY CLOUDY START TO
THE DAY. INTERESTING TO NOTE THE CLOUDS ARE NOT YOUR TYPICAL
MARINE LAYER...SODARS AND PROFILERS DO NOT INDICATE A DEFINED
MARINE LAYER. THE KOAK SOUNDING ON THE OTHER HAND DOES SHOW A
MOIST LOWER 5K FEET. SYNOPTICALLY SPEAKING...A WEAK UPPER LEVEL
DISTURBANCE IS CURRENTLY SITTING OFF THE SF BAY COAST. THE
ASSOCIATED LIFT AND MOIST LOWER 5K FT HELPED TO PRODUCE SOME LIGHT
SHOWERS OVERNIGHT WITH SEVERAL STATIONS MEASURING UP TO A TENTH.

FOR THE REST OF TODAY...ANOTHER STRONGER UPPER LOW IS FORECAST TO
DROP SOUTHWARD THROUGH THE BASE OF A BROAD UPPER TROUGH. THE
UPPER LOW CAN BE SEEN ON THE WATER VAPOR NEAR 130W. LATEST SHORT
TERM MODELS...THE HRRR AND RAP BOTH INDICATE INCREASED SHOWER
ACTIVITY THIS AFTERNOON AS THE UPPER LOW DEEPENS OFF THE COAST.
THE BEST CHANCE FOR SHOWERS WILL BE OVER TERRAIN FAVORED
LOCATIONS. IN FACT...THE LATEST NAM/HRRR INDICATE A LITTLE BIT OF
SFC INSTABILITY OVER THE E BAY HILLS AND THE GABILAN RANGE THIS
AFTERNOON. THEREFORE COULD NOT TOTALLY RULE OUT SOME THUNDER AS WELL.

GIVEN THE UNCERTAINTY OF ACTUAL LOCATIONS FOR SHOWER
ACTIVITY...LATEST FORECAST HAS BLANKET COVERAGE OF SHOWERS THIS
AFTERNOON. NO MAJOR UPDATE IS NEEDED AT THIS TIME...BUT WILL LIKE
TWEAK THE WEATHER GRIDS TO BETTER REFLECT REALITY THIS AFTERNOON.

&&

.PREV DISCUSSION...AS OF 3:58 AM PDT THURSDAY...THE TROUGH AND
UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY WITH
HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE EASTERN
PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND FOR
SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER TROUGH
WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 11:00 AM PDT THURSDAY...WIDESPREAD CLOUDS TODAY
ALONG WITH A DEEP ALBEIT POORLY DEFINED MARINE LAYER PLUS ONSHORE
SURFACE FLOW WILL KEEPS CIGS GOING IN ALL SPOTS THROUGH THE
PERIOD. DID MAKE SOME ADJUSTMENTS TO THE TAFS FROM THE PREVIOUS
PACKAGE TO KEEP CIGS LOWER IN MOST SPOTS. MVFR GENERALLY EXPECTED
TONIGHT. WINDS SPEEDS MOSTLY UNDER 15 KT EXCEPT AT SFO. A FEW LIGHT
SHOWERS ALSO POSSIBLE THROUGH THE PERIOD. MODERATE CONFIDENCE.

VICINITY OF KSFO...STILL SHOWING BKN015 ON THE 5 MINUTE OB
ALTHOUGH CAMS ARE SHOWING DEFINITE BREAKS AND LIFTING. WIDESPREAD
CLOUDS THROUGH THE AREA ALONG WITH WESTERLY FLOW AT THE SURFACE
SHOULD KEEPS CIGS GOING ALL DAY UNDER 5KFT. WESTERLY WINDS FROM
21Z TO 02Z AROUND 15 KT FROM 260 TO 280. MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR THROUGH THE PERIOD DUE TO
PERSISTENT ONSHORE FLOW PLUS DEEP MARINE LAYER. SPEEDS WILL PICK
UP THROUGH THE DAY WITH WESTERLY VALUES OF 8 TO 12 KT AFTER 20Z.
LOCALLY HIGHER GUSTS TO KSNS POSSIBLE. MODERATE CONFIDENCE.

&&

.MARINE...AS OF 11:00 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: BELL

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 211802
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1102 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 08:45 AM PDT THURSDAY...DEEP STRATUS DECK
COVERS MUCH OF THE BAY AREA THIS MORNING...MOSTLY CLOUDY START TO
THE DAY. INTERESTING TO NOTE THE CLOUDS ARE NOT YOUR TYPICAL
MARINE LAYER...SODARS AND PROFILERS DO NOT INDICATE A DEFINED
MARINE LAYER. THE KOAK SOUNDING ON THE OTHER HAND DOES SHOW A
MOIST LOWER 5K FEET. SYNOPTICALLY SPEAKING...A WEAK UPPER LEVEL
DISTURBANCE IS CURRENTLY SITTING OFF THE SF BAY COAST. THE
ASSOCIATED LIFT AND MOIST LOWER 5K FT HELPED TO PRODUCE SOME LIGHT
SHOWERS OVERNIGHT WITH SEVERAL STATIONS MEASURING UP TO A TENTH.

FOR THE REST OF TODAY...ANOTHER STRONGER UPPER LOW IS FORECAST TO
DROP SOUTHWARD THROUGH THE BASE OF A BROAD UPPER TROUGH. THE
UPPER LOW CAN BE SEEN ON THE WATER VAPOR NEAR 130W. LATEST SHORT
TERM MODELS...THE HRRR AND RAP BOTH INDICATE INCREASED SHOWER
ACTIVITY THIS AFTERNOON AS THE UPPER LOW DEEPENS OFF THE COAST.
THE BEST CHANCE FOR SHOWERS WILL BE OVER TERRAIN FAVORED
LOCATIONS. IN FACT...THE LATEST NAM/HRRR INDICATE A LITTLE BIT OF
SFC INSTABILITY OVER THE E BAY HILLS AND THE GABILAN RANGE THIS
AFTERNOON. THEREFORE COULD NOT TOTALLY RULE OUT SOME THUNDER AS WELL.

GIVEN THE UNCERTAINTY OF ACTUAL LOCATIONS FOR SHOWER
ACTIVITY...LATEST FORECAST HAS BLANKET COVERAGE OF SHOWERS THIS
AFTERNOON. NO MAJOR UPDATE IS NEEDED AT THIS TIME...BUT WILL LIKE
TWEAK THE WEATHER GRIDS TO BETTER REFLECT REALITY THIS AFTERNOON.

&&

.PREV DISCUSSION...AS OF 3:58 AM PDT THURSDAY...THE TROUGH AND
UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY WITH
HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE EASTERN
PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND FOR
SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER TROUGH
WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 11:00 AM PDT THURSDAY...WIDESPREAD CLOUDS TODAY
ALONG WITH A DEEP ALBEIT POORLY DEFINED MARINE LAYER PLUS ONSHORE
SURFACE FLOW WILL KEEPS CIGS GOING IN ALL SPOTS THROUGH THE
PERIOD. DID MAKE SOME ADJUSTMENTS TO THE TAFS FROM THE PREVIOUS
PACKAGE TO KEEP CIGS LOWER IN MOST SPOTS. MVFR GENERALLY EXPECTED
TONIGHT. WINDS SPEEDS MOSTLY UNDER 15 KT EXCEPT AT SFO. A FEW LIGHT
SHOWERS ALSO POSSIBLE THROUGH THE PERIOD. MODERATE CONFIDENCE.

VICINITY OF KSFO...STILL SHOWING BKN015 ON THE 5 MINUTE OB
ALTHOUGH CAMS ARE SHOWING DEFINITE BREAKS AND LIFTING. WIDESPREAD
CLOUDS THROUGH THE AREA ALONG WITH WESTERLY FLOW AT THE SURFACE
SHOULD KEEPS CIGS GOING ALL DAY UNDER 5KFT. WESTERLY WINDS FROM
21Z TO 02Z AROUND 15 KT FROM 260 TO 280. MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR THROUGH THE PERIOD DUE TO
PERSISTENT ONSHORE FLOW PLUS DEEP MARINE LAYER. SPEEDS WILL PICK
UP THROUGH THE DAY WITH WESTERLY VALUES OF 8 TO 12 KT AFTER 20Z.
LOCALLY HIGHER GUSTS TO KSNS POSSIBLE. MODERATE CONFIDENCE.

&&

.MARINE...AS OF 11:00 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: BELL

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 211802
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1102 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 08:45 AM PDT THURSDAY...DEEP STRATUS DECK
COVERS MUCH OF THE BAY AREA THIS MORNING...MOSTLY CLOUDY START TO
THE DAY. INTERESTING TO NOTE THE CLOUDS ARE NOT YOUR TYPICAL
MARINE LAYER...SODARS AND PROFILERS DO NOT INDICATE A DEFINED
MARINE LAYER. THE KOAK SOUNDING ON THE OTHER HAND DOES SHOW A
MOIST LOWER 5K FEET. SYNOPTICALLY SPEAKING...A WEAK UPPER LEVEL
DISTURBANCE IS CURRENTLY SITTING OFF THE SF BAY COAST. THE
ASSOCIATED LIFT AND MOIST LOWER 5K FT HELPED TO PRODUCE SOME LIGHT
SHOWERS OVERNIGHT WITH SEVERAL STATIONS MEASURING UP TO A TENTH.

FOR THE REST OF TODAY...ANOTHER STRONGER UPPER LOW IS FORECAST TO
DROP SOUTHWARD THROUGH THE BASE OF A BROAD UPPER TROUGH. THE
UPPER LOW CAN BE SEEN ON THE WATER VAPOR NEAR 130W. LATEST SHORT
TERM MODELS...THE HRRR AND RAP BOTH INDICATE INCREASED SHOWER
ACTIVITY THIS AFTERNOON AS THE UPPER LOW DEEPENS OFF THE COAST.
THE BEST CHANCE FOR SHOWERS WILL BE OVER TERRAIN FAVORED
LOCATIONS. IN FACT...THE LATEST NAM/HRRR INDICATE A LITTLE BIT OF
SFC INSTABILITY OVER THE E BAY HILLS AND THE GABILAN RANGE THIS
AFTERNOON. THEREFORE COULD NOT TOTALLY RULE OUT SOME THUNDER AS WELL.

GIVEN THE UNCERTAINTY OF ACTUAL LOCATIONS FOR SHOWER
ACTIVITY...LATEST FORECAST HAS BLANKET COVERAGE OF SHOWERS THIS
AFTERNOON. NO MAJOR UPDATE IS NEEDED AT THIS TIME...BUT WILL LIKE
TWEAK THE WEATHER GRIDS TO BETTER REFLECT REALITY THIS AFTERNOON.

&&

.PREV DISCUSSION...AS OF 3:58 AM PDT THURSDAY...THE TROUGH AND
UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY WITH
HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE EASTERN
PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND FOR
SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER TROUGH
WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 11:00 AM PDT THURSDAY...WIDESPREAD CLOUDS TODAY
ALONG WITH A DEEP ALBEIT POORLY DEFINED MARINE LAYER PLUS ONSHORE
SURFACE FLOW WILL KEEPS CIGS GOING IN ALL SPOTS THROUGH THE
PERIOD. DID MAKE SOME ADJUSTMENTS TO THE TAFS FROM THE PREVIOUS
PACKAGE TO KEEP CIGS LOWER IN MOST SPOTS. MVFR GENERALLY EXPECTED
TONIGHT. WINDS SPEEDS MOSTLY UNDER 15 KT EXCEPT AT SFO. A FEW LIGHT
SHOWERS ALSO POSSIBLE THROUGH THE PERIOD. MODERATE CONFIDENCE.

VICINITY OF KSFO...STILL SHOWING BKN015 ON THE 5 MINUTE OB
ALTHOUGH CAMS ARE SHOWING DEFINITE BREAKS AND LIFTING. WIDESPREAD
CLOUDS THROUGH THE AREA ALONG WITH WESTERLY FLOW AT THE SURFACE
SHOULD KEEPS CIGS GOING ALL DAY UNDER 5KFT. WESTERLY WINDS FROM
21Z TO 02Z AROUND 15 KT FROM 260 TO 280. MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR THROUGH THE PERIOD DUE TO
PERSISTENT ONSHORE FLOW PLUS DEEP MARINE LAYER. SPEEDS WILL PICK
UP THROUGH THE DAY WITH WESTERLY VALUES OF 8 TO 12 KT AFTER 20Z.
LOCALLY HIGHER GUSTS TO KSNS POSSIBLE. MODERATE CONFIDENCE.

&&

.MARINE...AS OF 11:00 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: BELL

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 211548
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
848 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 08:45 AM PDT THURSDAY...DEEP STRATUS DECK
COVERS MUCH OF THE BAY AREA THIS MORNING...MOSTLY CLOUDY START TO
THE DAY. INTERESTING TO NOTE THE CLOUDS ARE NOT YOUR TYPICAL
MARINE LAYER...SODARS AND PROFILERS DO NOT INDICATE A DEFINED
MARINE LAYER. THE KOAK SOUNDING ON THE OTHER HAND DOES SHOW A
MOIST LOWER 5K FEET. SYNOPTICALLY SPEAKING...A WEAK UPPER LEVEL
DISTURBANCE IS CURRENTLY SITTING OFF THE SF BAY COAST. THE
ASSOCIATED LIFT AND MOIST LOWER 5K FT HELPED TO PRODUCE SOME LIGHT
SHOWERS OVERNIGHT WITH SEVERAL STATIONS MEASURING UP TO A TENTH.

FOR THE REST OF TODAY...ANOTHER STRONGER UPPER LOW IS FORECAST TO
DROP SOUTHWARD THROUGH THE BASE OF A BROAD UPPER TROUGH. THE
UPPER LOW CAN BE SEEN ON THE WATER VAPOR NEAR 130W. LATEST SHORT
TERM MODELS...THE HRRR AND RAP BOTH INDICATE INCREASED SHOWER
ACTIVITY THIS AFTERNOON AS THE UPPER LOW DEEPENS OFF THE COAST.
THE BEST CHANCE FOR SHOWERS WILL BE OVER TERRAIN FAVORED
LOCATIONS. IN FACT...THE LATEST NAM/HRRR INDICATE A LITTLE BIT OF
SFC INSTABILITY OVER THE E BAY HILLS AND THE GABILAN RANGE THIS
AFTERNOON. THEREFORE COULD NOT TOTALLY RULE OUT SOME THUNDER AS WELL.

GIVEN THE UNCERTAINTY OF ACTUAL LOCATIONS FOR SHOWER
ACTIVITY...LATEST FORECAST HAS BLANKET COVERAGE OF SHOWERS THIS
AFTERNOON. NO MAJOR UPDATE IS NEEDED AT THIS TIME...BUT WILL LIKE
TWEAK THE WEATHER GRIDS TO BETTER REFLECT REALITY THIS AFTERNOON.

&&

.PREV DISCUSSION...AS OF 3:58 AM PDT THURSDAY...THE TROUGH AND
UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY WITH
HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE EASTERN
PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND FOR
SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER TROUGH
WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 4:57 AM PDT THURSDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUD COVER
OVER THE TERMINALS TODAY. HOWEVER...A SMALLER SCALE LOW PRESSURE
SYSTEM WORKING ITS WAY TOWARDS THE CENTRAL CALIFORNIA COAST WILL
LIFT THE CLOUD DECK A BIT LATER THIS MORNING INTO THE AFTERNOON
HOURS PROVIDING THE AREA WITH A POSSIBILITY OF SHOWERS.

VICINITY OF KSFO...MVFR CIGS BKN-OVC030 ARE EXPECTED TO IMPROVE TO
VFR BKN-OVC035-050 LATER THIS MORNING INTO THE AFTERNOON HOURS. A
PERIOD OF BKN015 WILL BE POSSIBLE DURING THE EARLY MORNING HOURS. A
SLIGHT CHANCE OF SHOWERS IS ALSO IN THE GENERAL AREA FORECAST.
WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS BKN-OVC030 ARE EXPECTED
TO PREVAIL TODAY WITH A PERIOD OF BKN012 POSSIBLE EARLY THIS
MORNING. A SLIGHT CHANCE OF SHOWERS IS IN THE GENERAL AREA
FORECAST FOR THE LATE MORNING AFTERNOON HOURS. WESTERLY WINDS WILL
REACH 10 KT THIS AFTERNOON WITH STRONGER GUSTS IN THE SALINAS
VALLEY.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 211548
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
848 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 08:45 AM PDT THURSDAY...DEEP STRATUS DECK
COVERS MUCH OF THE BAY AREA THIS MORNING...MOSTLY CLOUDY START TO
THE DAY. INTERESTING TO NOTE THE CLOUDS ARE NOT YOUR TYPICAL
MARINE LAYER...SODARS AND PROFILERS DO NOT INDICATE A DEFINED
MARINE LAYER. THE KOAK SOUNDING ON THE OTHER HAND DOES SHOW A
MOIST LOWER 5K FEET. SYNOPTICALLY SPEAKING...A WEAK UPPER LEVEL
DISTURBANCE IS CURRENTLY SITTING OFF THE SF BAY COAST. THE
ASSOCIATED LIFT AND MOIST LOWER 5K FT HELPED TO PRODUCE SOME LIGHT
SHOWERS OVERNIGHT WITH SEVERAL STATIONS MEASURING UP TO A TENTH.

FOR THE REST OF TODAY...ANOTHER STRONGER UPPER LOW IS FORECAST TO
DROP SOUTHWARD THROUGH THE BASE OF A BROAD UPPER TROUGH. THE
UPPER LOW CAN BE SEEN ON THE WATER VAPOR NEAR 130W. LATEST SHORT
TERM MODELS...THE HRRR AND RAP BOTH INDICATE INCREASED SHOWER
ACTIVITY THIS AFTERNOON AS THE UPPER LOW DEEPENS OFF THE COAST.
THE BEST CHANCE FOR SHOWERS WILL BE OVER TERRAIN FAVORED
LOCATIONS. IN FACT...THE LATEST NAM/HRRR INDICATE A LITTLE BIT OF
SFC INSTABILITY OVER THE E BAY HILLS AND THE GABILAN RANGE THIS
AFTERNOON. THEREFORE COULD NOT TOTALLY RULE OUT SOME THUNDER AS WELL.

GIVEN THE UNCERTAINTY OF ACTUAL LOCATIONS FOR SHOWER
ACTIVITY...LATEST FORECAST HAS BLANKET COVERAGE OF SHOWERS THIS
AFTERNOON. NO MAJOR UPDATE IS NEEDED AT THIS TIME...BUT WILL LIKE
TWEAK THE WEATHER GRIDS TO BETTER REFLECT REALITY THIS AFTERNOON.

&&

.PREV DISCUSSION...AS OF 3:58 AM PDT THURSDAY...THE TROUGH AND
UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY WITH
HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE EASTERN
PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND FOR
SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER TROUGH
WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 4:57 AM PDT THURSDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUD COVER
OVER THE TERMINALS TODAY. HOWEVER...A SMALLER SCALE LOW PRESSURE
SYSTEM WORKING ITS WAY TOWARDS THE CENTRAL CALIFORNIA COAST WILL
LIFT THE CLOUD DECK A BIT LATER THIS MORNING INTO THE AFTERNOON
HOURS PROVIDING THE AREA WITH A POSSIBILITY OF SHOWERS.

VICINITY OF KSFO...MVFR CIGS BKN-OVC030 ARE EXPECTED TO IMPROVE TO
VFR BKN-OVC035-050 LATER THIS MORNING INTO THE AFTERNOON HOURS. A
PERIOD OF BKN015 WILL BE POSSIBLE DURING THE EARLY MORNING HOURS. A
SLIGHT CHANCE OF SHOWERS IS ALSO IN THE GENERAL AREA FORECAST.
WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS BKN-OVC030 ARE EXPECTED
TO PREVAIL TODAY WITH A PERIOD OF BKN012 POSSIBLE EARLY THIS
MORNING. A SLIGHT CHANCE OF SHOWERS IS IN THE GENERAL AREA
FORECAST FOR THE LATE MORNING AFTERNOON HOURS. WESTERLY WINDS WILL
REACH 10 KT THIS AFTERNOON WITH STRONGER GUSTS IN THE SALINAS
VALLEY.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: MM
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA








000
FXUS66 KMTR 211156
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
456 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 3:58 AM PDT THURSDAY...COASTAL CLOUDS HAVE
SPREAD INLAND AND COVER MOST OF THE CWA AT THIS TIME. GENERALLY
CEILINGS ARE HIGH...FROM 1500 TO 3000 FEET...AND INTERMITTENT
LIGHT RAIN OR DRIZZLE HAS BEEN NOTED AROUND OAKLAND AND SAN
FRANCISCO FOR THE PAST FEW HOURS. SO FAR DOWNTOWN SAN FRANCISCO
HAS PICKED UP 0.05 INCHES SINCE LATE LAST EVENING.

THE UPPER LEVEL TROUGH LOCATED WEST OF SAN FRANCISCO WILL CONTINUE
TO PROVIDE COOL AND OCCASIONALLY UNSTABLE AIRMASS TO THE AREA.
UPPER LOW CENTERS WITHIN THE TROUGH WILL ROTATE AROUND THE TROUGH
AND OFFER EPISODES OF LIGHT RAIN OR DRIZZLE DURING THE MORNING AS
WELL AS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS IN THE
AFTERNOONS...ESPECIALLY ACROSS THE SOUTHERN INTERIOR. THE TROUGH
AND UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY
WITH HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE
EASTERN PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND
FOR SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER
TROUGH WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 4:57 AM PDT THURSDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUD COVER
OVER THE TERMINALS TODAY. HOWEVER...A SMALLER SCALE LOW PRESSURE
SYSTEM WORKING ITS WAY TOWARDS THE CENTRAL CALIFORNIA COAST WILL
LIFT THE CLOUD DECK A BIT LATER THIS MORNING INTO THE AFTERNOON
HOURS PROVIDING THE AREA WITH A POSSIBILITY OF SHOWERS.

VICINITY OF KSFO...MVFR CIGS BKN-OVC030 ARE EXPECTED TO IMPROVE TO
VFR BKN-OVC035-050 LATER THIS MORNING INTO THE AFTERNOON HOURS. A
PERIOD OF BKN015 WILL BE POSSIBLE DURING THE EARLY MORNING HOURS. A
SLIGHT CHANCE OF SHOWERS IS ALSO IN THE GENERAL AREA FORECAST.
WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS BKN-OVC030 ARE EXPECTED
TO PREVAIL TODAY WITH A PERIOD OF BKN012 POSSIBLE EARLY THIS
MORNING. A SLIGHT CHANCE OF SHOWERS IS IN THE GENERAL AREA
FORECAST FOR THE LATE MORNING AFTERNOON HOURS. WESTERLY WINDS WILL
REACH 10 KT THIS AFTERNOON WITH STRONGER GUSTS IN THE SALINAS
VALLEY.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 211156
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
456 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 3:58 AM PDT THURSDAY...COASTAL CLOUDS HAVE
SPREAD INLAND AND COVER MOST OF THE CWA AT THIS TIME. GENERALLY
CEILINGS ARE HIGH...FROM 1500 TO 3000 FEET...AND INTERMITTENT
LIGHT RAIN OR DRIZZLE HAS BEEN NOTED AROUND OAKLAND AND SAN
FRANCISCO FOR THE PAST FEW HOURS. SO FAR DOWNTOWN SAN FRANCISCO
HAS PICKED UP 0.05 INCHES SINCE LATE LAST EVENING.

THE UPPER LEVEL TROUGH LOCATED WEST OF SAN FRANCISCO WILL CONTINUE
TO PROVIDE COOL AND OCCASIONALLY UNSTABLE AIRMASS TO THE AREA.
UPPER LOW CENTERS WITHIN THE TROUGH WILL ROTATE AROUND THE TROUGH
AND OFFER EPISODES OF LIGHT RAIN OR DRIZZLE DURING THE MORNING AS
WELL AS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS IN THE
AFTERNOONS...ESPECIALLY ACROSS THE SOUTHERN INTERIOR. THE TROUGH
AND UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY
WITH HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE
EASTERN PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND
FOR SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER
TROUGH WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 4:57 AM PDT THURSDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUD COVER
OVER THE TERMINALS TODAY. HOWEVER...A SMALLER SCALE LOW PRESSURE
SYSTEM WORKING ITS WAY TOWARDS THE CENTRAL CALIFORNIA COAST WILL
LIFT THE CLOUD DECK A BIT LATER THIS MORNING INTO THE AFTERNOON
HOURS PROVIDING THE AREA WITH A POSSIBILITY OF SHOWERS.

VICINITY OF KSFO...MVFR CIGS BKN-OVC030 ARE EXPECTED TO IMPROVE TO
VFR BKN-OVC035-050 LATER THIS MORNING INTO THE AFTERNOON HOURS. A
PERIOD OF BKN015 WILL BE POSSIBLE DURING THE EARLY MORNING HOURS. A
SLIGHT CHANCE OF SHOWERS IS ALSO IN THE GENERAL AREA FORECAST.
WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS BKN-OVC030 ARE EXPECTED
TO PREVAIL TODAY WITH A PERIOD OF BKN012 POSSIBLE EARLY THIS
MORNING. A SLIGHT CHANCE OF SHOWERS IS IN THE GENERAL AREA
FORECAST FOR THE LATE MORNING AFTERNOON HOURS. WESTERLY WINDS WILL
REACH 10 KT THIS AFTERNOON WITH STRONGER GUSTS IN THE SALINAS
VALLEY.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 211156
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
456 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 3:58 AM PDT THURSDAY...COASTAL CLOUDS HAVE
SPREAD INLAND AND COVER MOST OF THE CWA AT THIS TIME. GENERALLY
CEILINGS ARE HIGH...FROM 1500 TO 3000 FEET...AND INTERMITTENT
LIGHT RAIN OR DRIZZLE HAS BEEN NOTED AROUND OAKLAND AND SAN
FRANCISCO FOR THE PAST FEW HOURS. SO FAR DOWNTOWN SAN FRANCISCO
HAS PICKED UP 0.05 INCHES SINCE LATE LAST EVENING.

THE UPPER LEVEL TROUGH LOCATED WEST OF SAN FRANCISCO WILL CONTINUE
TO PROVIDE COOL AND OCCASIONALLY UNSTABLE AIRMASS TO THE AREA.
UPPER LOW CENTERS WITHIN THE TROUGH WILL ROTATE AROUND THE TROUGH
AND OFFER EPISODES OF LIGHT RAIN OR DRIZZLE DURING THE MORNING AS
WELL AS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS IN THE
AFTERNOONS...ESPECIALLY ACROSS THE SOUTHERN INTERIOR. THE TROUGH
AND UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY
WITH HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE
EASTERN PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND
FOR SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER
TROUGH WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 4:57 AM PDT THURSDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUD COVER
OVER THE TERMINALS TODAY. HOWEVER...A SMALLER SCALE LOW PRESSURE
SYSTEM WORKING ITS WAY TOWARDS THE CENTRAL CALIFORNIA COAST WILL
LIFT THE CLOUD DECK A BIT LATER THIS MORNING INTO THE AFTERNOON
HOURS PROVIDING THE AREA WITH A POSSIBILITY OF SHOWERS.

VICINITY OF KSFO...MVFR CIGS BKN-OVC030 ARE EXPECTED TO IMPROVE TO
VFR BKN-OVC035-050 LATER THIS MORNING INTO THE AFTERNOON HOURS. A
PERIOD OF BKN015 WILL BE POSSIBLE DURING THE EARLY MORNING HOURS. A
SLIGHT CHANCE OF SHOWERS IS ALSO IN THE GENERAL AREA FORECAST.
WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS BKN-OVC030 ARE EXPECTED
TO PREVAIL TODAY WITH A PERIOD OF BKN012 POSSIBLE EARLY THIS
MORNING. A SLIGHT CHANCE OF SHOWERS IS IN THE GENERAL AREA
FORECAST FOR THE LATE MORNING AFTERNOON HOURS. WESTERLY WINDS WILL
REACH 10 KT THIS AFTERNOON WITH STRONGER GUSTS IN THE SALINAS
VALLEY.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSBAYAREA
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000
FXUS66 KMTR 211156
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
456 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 3:58 AM PDT THURSDAY...COASTAL CLOUDS HAVE
SPREAD INLAND AND COVER MOST OF THE CWA AT THIS TIME. GENERALLY
CEILINGS ARE HIGH...FROM 1500 TO 3000 FEET...AND INTERMITTENT
LIGHT RAIN OR DRIZZLE HAS BEEN NOTED AROUND OAKLAND AND SAN
FRANCISCO FOR THE PAST FEW HOURS. SO FAR DOWNTOWN SAN FRANCISCO
HAS PICKED UP 0.05 INCHES SINCE LATE LAST EVENING.

THE UPPER LEVEL TROUGH LOCATED WEST OF SAN FRANCISCO WILL CONTINUE
TO PROVIDE COOL AND OCCASIONALLY UNSTABLE AIRMASS TO THE AREA.
UPPER LOW CENTERS WITHIN THE TROUGH WILL ROTATE AROUND THE TROUGH
AND OFFER EPISODES OF LIGHT RAIN OR DRIZZLE DURING THE MORNING AS
WELL AS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS IN THE
AFTERNOONS...ESPECIALLY ACROSS THE SOUTHERN INTERIOR. THE TROUGH
AND UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY
WITH HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE
EASTERN PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND
FOR SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER
TROUGH WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 4:57 AM PDT THURSDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUD COVER
OVER THE TERMINALS TODAY. HOWEVER...A SMALLER SCALE LOW PRESSURE
SYSTEM WORKING ITS WAY TOWARDS THE CENTRAL CALIFORNIA COAST WILL
LIFT THE CLOUD DECK A BIT LATER THIS MORNING INTO THE AFTERNOON
HOURS PROVIDING THE AREA WITH A POSSIBILITY OF SHOWERS.

VICINITY OF KSFO...MVFR CIGS BKN-OVC030 ARE EXPECTED TO IMPROVE TO
VFR BKN-OVC035-050 LATER THIS MORNING INTO THE AFTERNOON HOURS. A
PERIOD OF BKN015 WILL BE POSSIBLE DURING THE EARLY MORNING HOURS. A
SLIGHT CHANCE OF SHOWERS IS ALSO IN THE GENERAL AREA FORECAST.
WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS BKN-OVC030 ARE EXPECTED
TO PREVAIL TODAY WITH A PERIOD OF BKN012 POSSIBLE EARLY THIS
MORNING. A SLIGHT CHANCE OF SHOWERS IS IN THE GENERAL AREA
FORECAST FOR THE LATE MORNING AFTERNOON HOURS. WESTERLY WINDS WILL
REACH 10 KT THIS AFTERNOON WITH STRONGER GUSTS IN THE SALINAS
VALLEY.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 211058
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
358 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 3:58 AM PDT THURSDAY...COASTAL CLOUDS HAVE
SPREAD INLAND AND COVER MOST OF THE CWA AT THIS TIME. GENERALLY
CEILINGS ARE HIGH...FROM 1500 TO 3000 FEET...AND INTERMITTENT
LIGHT RAIN OR DRIZZLE HAS BEEN NOTED AROUND OAKLAND AND SAN
FRANCISCO FOR THE PAST FEW HOURS. SO FAR DOWNTOWN SAN FRANCISCO
HAS PICKED UP 0.05 INCHES SINCE LATE LAST EVENING.

THE UPPER LEVEL TROUGH LOCATED WEST OF SAN FRANCISCO WILL CONTINUE
TO PROVIDE COOL AND OCCASIONALLY UNSTABLE AIRMASS TO THE AREA.
UPPER LOW CENTERS WITHIN THE TROUGH WILL ROTATE AROUND THE TROUGH
AND OFFER EPISODES OF LIGHT RAIN OR DRIZZLE DURING THE MORNING AS
WELL AS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS IN THE
AFTERNOONS...ESPECIALLY ACROSS THE SOUTHERN INTERIOR. THE TROUGH
AND UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY
WITH HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE
EASTERN PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND
FOR SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER
TROUGH WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 10:44 PM PDT WEDNESDAY...LOW CLOUD ARE FILLING
IN ACROSS THE REGION WITH BORDERLINE IFR/MVFR CIGS BEING REPORTED.
ONSHORE FLOW WILL PREVAIL THROUGH TONIGHT WITH GUSTIER WINDS
FORECAST THURSDAY AFTERNOON. THE LOW SITUATED OVER THE REGION IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...BORDERLINE IFR/MVFR CIGS EXPECTED THROUGH
TONIGHT. CIGS ARE EXPECTED TO LIFT A BIT THURSDAY RESULTING IN
-DZ AND VCSH. ONSHORE FLOW WILL PREVAIL.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED THROUGH MUCH OF
THE FORECAST PERIOD. ONSHORE FLOW WILL CONTINUE. -DZ AND VCSH POSS
THURSDAY MORNING.

&&

.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: CW
MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 211058
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
358 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 3:58 AM PDT THURSDAY...COASTAL CLOUDS HAVE
SPREAD INLAND AND COVER MOST OF THE CWA AT THIS TIME. GENERALLY
CEILINGS ARE HIGH...FROM 1500 TO 3000 FEET...AND INTERMITTENT
LIGHT RAIN OR DRIZZLE HAS BEEN NOTED AROUND OAKLAND AND SAN
FRANCISCO FOR THE PAST FEW HOURS. SO FAR DOWNTOWN SAN FRANCISCO
HAS PICKED UP 0.05 INCHES SINCE LATE LAST EVENING.

THE UPPER LEVEL TROUGH LOCATED WEST OF SAN FRANCISCO WILL CONTINUE
TO PROVIDE COOL AND OCCASIONALLY UNSTABLE AIRMASS TO THE AREA.
UPPER LOW CENTERS WITHIN THE TROUGH WILL ROTATE AROUND THE TROUGH
AND OFFER EPISODES OF LIGHT RAIN OR DRIZZLE DURING THE MORNING AS
WELL AS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS IN THE
AFTERNOONS...ESPECIALLY ACROSS THE SOUTHERN INTERIOR. THE TROUGH
AND UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY
WITH HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE
EASTERN PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND
FOR SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER
TROUGH WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 10:44 PM PDT WEDNESDAY...LOW CLOUD ARE FILLING
IN ACROSS THE REGION WITH BORDERLINE IFR/MVFR CIGS BEING REPORTED.
ONSHORE FLOW WILL PREVAIL THROUGH TONIGHT WITH GUSTIER WINDS
FORECAST THURSDAY AFTERNOON. THE LOW SITUATED OVER THE REGION IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...BORDERLINE IFR/MVFR CIGS EXPECTED THROUGH
TONIGHT. CIGS ARE EXPECTED TO LIFT A BIT THURSDAY RESULTING IN
-DZ AND VCSH. ONSHORE FLOW WILL PREVAIL.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED THROUGH MUCH OF
THE FORECAST PERIOD. ONSHORE FLOW WILL CONTINUE. -DZ AND VCSH POSS
THURSDAY MORNING.

&&

.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: CW
MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA








000
FXUS66 KMTR 211058
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
358 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 3:58 AM PDT THURSDAY...COASTAL CLOUDS HAVE
SPREAD INLAND AND COVER MOST OF THE CWA AT THIS TIME. GENERALLY
CEILINGS ARE HIGH...FROM 1500 TO 3000 FEET...AND INTERMITTENT
LIGHT RAIN OR DRIZZLE HAS BEEN NOTED AROUND OAKLAND AND SAN
FRANCISCO FOR THE PAST FEW HOURS. SO FAR DOWNTOWN SAN FRANCISCO
HAS PICKED UP 0.05 INCHES SINCE LATE LAST EVENING.

THE UPPER LEVEL TROUGH LOCATED WEST OF SAN FRANCISCO WILL CONTINUE
TO PROVIDE COOL AND OCCASIONALLY UNSTABLE AIRMASS TO THE AREA.
UPPER LOW CENTERS WITHIN THE TROUGH WILL ROTATE AROUND THE TROUGH
AND OFFER EPISODES OF LIGHT RAIN OR DRIZZLE DURING THE MORNING AS
WELL AS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS IN THE
AFTERNOONS...ESPECIALLY ACROSS THE SOUTHERN INTERIOR. THE TROUGH
AND UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY
WITH HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE
EASTERN PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND
FOR SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER
TROUGH WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 10:44 PM PDT WEDNESDAY...LOW CLOUD ARE FILLING
IN ACROSS THE REGION WITH BORDERLINE IFR/MVFR CIGS BEING REPORTED.
ONSHORE FLOW WILL PREVAIL THROUGH TONIGHT WITH GUSTIER WINDS
FORECAST THURSDAY AFTERNOON. THE LOW SITUATED OVER THE REGION IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...BORDERLINE IFR/MVFR CIGS EXPECTED THROUGH
TONIGHT. CIGS ARE EXPECTED TO LIFT A BIT THURSDAY RESULTING IN
-DZ AND VCSH. ONSHORE FLOW WILL PREVAIL.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED THROUGH MUCH OF
THE FORECAST PERIOD. ONSHORE FLOW WILL CONTINUE. -DZ AND VCSH POSS
THURSDAY MORNING.

&&

.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: CW
MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 211058
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
358 AM PDT THU MAY 21 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 3:58 AM PDT THURSDAY...COASTAL CLOUDS HAVE
SPREAD INLAND AND COVER MOST OF THE CWA AT THIS TIME. GENERALLY
CEILINGS ARE HIGH...FROM 1500 TO 3000 FEET...AND INTERMITTENT
LIGHT RAIN OR DRIZZLE HAS BEEN NOTED AROUND OAKLAND AND SAN
FRANCISCO FOR THE PAST FEW HOURS. SO FAR DOWNTOWN SAN FRANCISCO
HAS PICKED UP 0.05 INCHES SINCE LATE LAST EVENING.

THE UPPER LEVEL TROUGH LOCATED WEST OF SAN FRANCISCO WILL CONTINUE
TO PROVIDE COOL AND OCCASIONALLY UNSTABLE AIRMASS TO THE AREA.
UPPER LOW CENTERS WITHIN THE TROUGH WILL ROTATE AROUND THE TROUGH
AND OFFER EPISODES OF LIGHT RAIN OR DRIZZLE DURING THE MORNING AS
WELL AS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS IN THE
AFTERNOONS...ESPECIALLY ACROSS THE SOUTHERN INTERIOR. THE TROUGH
AND UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY
WITH HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE
EASTERN PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND
FOR SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER
TROUGH WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 10:44 PM PDT WEDNESDAY...LOW CLOUD ARE FILLING
IN ACROSS THE REGION WITH BORDERLINE IFR/MVFR CIGS BEING REPORTED.
ONSHORE FLOW WILL PREVAIL THROUGH TONIGHT WITH GUSTIER WINDS
FORECAST THURSDAY AFTERNOON. THE LOW SITUATED OVER THE REGION IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...BORDERLINE IFR/MVFR CIGS EXPECTED THROUGH
TONIGHT. CIGS ARE EXPECTED TO LIFT A BIT THURSDAY RESULTING IN
-DZ AND VCSH. ONSHORE FLOW WILL PREVAIL.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED THROUGH MUCH OF
THE FORECAST PERIOD. ONSHORE FLOW WILL CONTINUE. -DZ AND VCSH POSS
THURSDAY MORNING.

&&

.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: CW
MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA








000
FXUS66 KMTR 210544
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1044 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 9:00 PM PDT WEDNESDAY...UPPER LEVEL TROUGH JUST
WEST OF SAN FRANCISCO BROUGHT ANOTHER DAY OF COOL TEMPERATURES TO
THE AREA. STRATUS BURNED OFF IN SOME AREAS THIS AFTERNOON BUT OAK
SOUNDING SHOWS A DEEP MARINE LAYER AROUND 3000 FEET SO LOW CLOUDS
WILL REDEVELOP AND EXTEND WELL INLAND TONIGHT.

A STRONG DISTURBANCE APPROACHING THE BACK SIDE OF THE TROUGH WILL
INTENSIFY THE TROUGH AND PUSH IT TOWARDS SOUTHERN CALIFORNIA ON THURSDAY.
THIS WILL HELP DEEPEN THE MARINE LAYER EVEN MORE ON THURSDAY...TO
THE POINT WHERE THERE COULD BE LOCAL DRIZZLE OR LIGHT SHOWERS.
THIS ALSO RENEWS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS OVER
THE MOUNTAINS WITH THE BEST CHANCES OVER THE SAN BENITO COUNTY
MOUNTAINS. THE LATEST HRRR AND WRF MODELS SHOW SCATTERED PRECIP
AMOUNTS OF 1 TO 3 HUNDREDTHS OF AN INCH NEAR THE COAST AND LIGHT
CONVECTIVE PRECIP IN THE SAN BENITO COUNTY MOUNTAINS.

SLIGHT PRECIP CHANCES CONTINUE INTO FRIDAY AS THE LOW MOVES INLAND
OVER SOUTHERN CALIFORNIA BUT THUNDERSTORM CHANCES WILL BE
DIMINISHED ON THE BACK SIDE OF THE LOW. PRECIP CHANCES END FRIDAY
NIGHT.

PREVIOUS MODEL RUNS INDICATED AN UPPER LEVEL RIDGE BUILDING OFF
THE COAST THIS WEEKEND BUT LATEST MODELS ARE BRINGING ANOTHER
UPPER LEVEL DISTURBANCE ALONG THE BACK SIDE OF THE LOW THROUGH
THE NORTHERN CALIFORNIA INTERIOR ON SATURDAY WITH ONLY WEAK
RIDGING SUNDAY AND MONDAY. DRY WEATHER IS STILL EXPECTED AND
TEMPERATURES SHOULD STILL WARM UP SATURDAY THROUGH MONDAY BUT NOT
AS MUCH AS ORIGINALLY THOUGHT.

&&

.AVIATION...AS OF 10:44 PM PDT WEDNESDAY...LOW CLOUD ARE FILLING
IN ACROSS THE REGION WITH BORDERLINE IFR/MVFR CIGS BEING REPORTED.
ONSHORE FLOW WILL PREVAIL THROUGH TONIGHT WITH GUSTIER WINDS
FORECAST THURSDAY AFTERNOON. THE LOW SITUATED OVER THE REGION IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...BORDERLINE IFR/MVFR CIGS EXPECTED THROUGH
TONIGHT. CIGS ARE EXPECTED TO LIFT A BIT THURSDAY RESULTING IN
-DZ AND VCSH. ONSHORE FLOW WILL PREVAIL.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED THROUGH MUCH OF
THE FORECAST PERIOD. ONSHORE FLOW WILL CONTINUE. -DZ AND VCSH POSS
THURSDAY MORNING.

&&

.MARINE...AS OF 8:44 PM PDT WEDNESDAY...UNSETTLED WEATHER IS
EXPECTED OVER THE COASTAL WATERS AS A STORM SYSTEM WILL MOVE
THROUGH THE REGION THURSDAY AND FRIDAY. LIGHT TO MODERATE
NORTHERLY WINDS WILL CONTINUE AS THE STORM SYSTEM SLIDES THROUGH.
NORTHERLY WINDS WILL INCREASE FRIDAY AND OVER THE WEEKEND AS THE
NORTHERLY PRESSURE GRADIENT INCREASES.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

$$

PUBLIC FORECAST: W PI
AVIATION/MARINE: CW

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 210544
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1044 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 9:00 PM PDT WEDNESDAY...UPPER LEVEL TROUGH JUST
WEST OF SAN FRANCISCO BROUGHT ANOTHER DAY OF COOL TEMPERATURES TO
THE AREA. STRATUS BURNED OFF IN SOME AREAS THIS AFTERNOON BUT OAK
SOUNDING SHOWS A DEEP MARINE LAYER AROUND 3000 FEET SO LOW CLOUDS
WILL REDEVELOP AND EXTEND WELL INLAND TONIGHT.

A STRONG DISTURBANCE APPROACHING THE BACK SIDE OF THE TROUGH WILL
INTENSIFY THE TROUGH AND PUSH IT TOWARDS SOUTHERN CALIFORNIA ON THURSDAY.
THIS WILL HELP DEEPEN THE MARINE LAYER EVEN MORE ON THURSDAY...TO
THE POINT WHERE THERE COULD BE LOCAL DRIZZLE OR LIGHT SHOWERS.
THIS ALSO RENEWS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS OVER
THE MOUNTAINS WITH THE BEST CHANCES OVER THE SAN BENITO COUNTY
MOUNTAINS. THE LATEST HRRR AND WRF MODELS SHOW SCATTERED PRECIP
AMOUNTS OF 1 TO 3 HUNDREDTHS OF AN INCH NEAR THE COAST AND LIGHT
CONVECTIVE PRECIP IN THE SAN BENITO COUNTY MOUNTAINS.

SLIGHT PRECIP CHANCES CONTINUE INTO FRIDAY AS THE LOW MOVES INLAND
OVER SOUTHERN CALIFORNIA BUT THUNDERSTORM CHANCES WILL BE
DIMINISHED ON THE BACK SIDE OF THE LOW. PRECIP CHANCES END FRIDAY
NIGHT.

PREVIOUS MODEL RUNS INDICATED AN UPPER LEVEL RIDGE BUILDING OFF
THE COAST THIS WEEKEND BUT LATEST MODELS ARE BRINGING ANOTHER
UPPER LEVEL DISTURBANCE ALONG THE BACK SIDE OF THE LOW THROUGH
THE NORTHERN CALIFORNIA INTERIOR ON SATURDAY WITH ONLY WEAK
RIDGING SUNDAY AND MONDAY. DRY WEATHER IS STILL EXPECTED AND
TEMPERATURES SHOULD STILL WARM UP SATURDAY THROUGH MONDAY BUT NOT
AS MUCH AS ORIGINALLY THOUGHT.

&&

.AVIATION...AS OF 10:44 PM PDT WEDNESDAY...LOW CLOUD ARE FILLING
IN ACROSS THE REGION WITH BORDERLINE IFR/MVFR CIGS BEING REPORTED.
ONSHORE FLOW WILL PREVAIL THROUGH TONIGHT WITH GUSTIER WINDS
FORECAST THURSDAY AFTERNOON. THE LOW SITUATED OVER THE REGION IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...BORDERLINE IFR/MVFR CIGS EXPECTED THROUGH
TONIGHT. CIGS ARE EXPECTED TO LIFT A BIT THURSDAY RESULTING IN
-DZ AND VCSH. ONSHORE FLOW WILL PREVAIL.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED THROUGH MUCH OF
THE FORECAST PERIOD. ONSHORE FLOW WILL CONTINUE. -DZ AND VCSH POSS
THURSDAY MORNING.

&&

.MARINE...AS OF 8:44 PM PDT WEDNESDAY...UNSETTLED WEATHER IS
EXPECTED OVER THE COASTAL WATERS AS A STORM SYSTEM WILL MOVE
THROUGH THE REGION THURSDAY AND FRIDAY. LIGHT TO MODERATE
NORTHERLY WINDS WILL CONTINUE AS THE STORM SYSTEM SLIDES THROUGH.
NORTHERLY WINDS WILL INCREASE FRIDAY AND OVER THE WEEKEND AS THE
NORTHERLY PRESSURE GRADIENT INCREASES.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

$$

PUBLIC FORECAST: W PI
AVIATION/MARINE: CW

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 210544
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1044 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 9:00 PM PDT WEDNESDAY...UPPER LEVEL TROUGH JUST
WEST OF SAN FRANCISCO BROUGHT ANOTHER DAY OF COOL TEMPERATURES TO
THE AREA. STRATUS BURNED OFF IN SOME AREAS THIS AFTERNOON BUT OAK
SOUNDING SHOWS A DEEP MARINE LAYER AROUND 3000 FEET SO LOW CLOUDS
WILL REDEVELOP AND EXTEND WELL INLAND TONIGHT.

A STRONG DISTURBANCE APPROACHING THE BACK SIDE OF THE TROUGH WILL
INTENSIFY THE TROUGH AND PUSH IT TOWARDS SOUTHERN CALIFORNIA ON THURSDAY.
THIS WILL HELP DEEPEN THE MARINE LAYER EVEN MORE ON THURSDAY...TO
THE POINT WHERE THERE COULD BE LOCAL DRIZZLE OR LIGHT SHOWERS.
THIS ALSO RENEWS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS OVER
THE MOUNTAINS WITH THE BEST CHANCES OVER THE SAN BENITO COUNTY
MOUNTAINS. THE LATEST HRRR AND WRF MODELS SHOW SCATTERED PRECIP
AMOUNTS OF 1 TO 3 HUNDREDTHS OF AN INCH NEAR THE COAST AND LIGHT
CONVECTIVE PRECIP IN THE SAN BENITO COUNTY MOUNTAINS.

SLIGHT PRECIP CHANCES CONTINUE INTO FRIDAY AS THE LOW MOVES INLAND
OVER SOUTHERN CALIFORNIA BUT THUNDERSTORM CHANCES WILL BE
DIMINISHED ON THE BACK SIDE OF THE LOW. PRECIP CHANCES END FRIDAY
NIGHT.

PREVIOUS MODEL RUNS INDICATED AN UPPER LEVEL RIDGE BUILDING OFF
THE COAST THIS WEEKEND BUT LATEST MODELS ARE BRINGING ANOTHER
UPPER LEVEL DISTURBANCE ALONG THE BACK SIDE OF THE LOW THROUGH
THE NORTHERN CALIFORNIA INTERIOR ON SATURDAY WITH ONLY WEAK
RIDGING SUNDAY AND MONDAY. DRY WEATHER IS STILL EXPECTED AND
TEMPERATURES SHOULD STILL WARM UP SATURDAY THROUGH MONDAY BUT NOT
AS MUCH AS ORIGINALLY THOUGHT.

&&

.AVIATION...AS OF 10:44 PM PDT WEDNESDAY...LOW CLOUD ARE FILLING
IN ACROSS THE REGION WITH BORDERLINE IFR/MVFR CIGS BEING REPORTED.
ONSHORE FLOW WILL PREVAIL THROUGH TONIGHT WITH GUSTIER WINDS
FORECAST THURSDAY AFTERNOON. THE LOW SITUATED OVER THE REGION IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...BORDERLINE IFR/MVFR CIGS EXPECTED THROUGH
TONIGHT. CIGS ARE EXPECTED TO LIFT A BIT THURSDAY RESULTING IN
-DZ AND VCSH. ONSHORE FLOW WILL PREVAIL.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED THROUGH MUCH OF
THE FORECAST PERIOD. ONSHORE FLOW WILL CONTINUE. -DZ AND VCSH POSS
THURSDAY MORNING.

&&

.MARINE...AS OF 8:44 PM PDT WEDNESDAY...UNSETTLED WEATHER IS
EXPECTED OVER THE COASTAL WATERS AS A STORM SYSTEM WILL MOVE
THROUGH THE REGION THURSDAY AND FRIDAY. LIGHT TO MODERATE
NORTHERLY WINDS WILL CONTINUE AS THE STORM SYSTEM SLIDES THROUGH.
NORTHERLY WINDS WILL INCREASE FRIDAY AND OVER THE WEEKEND AS THE
NORTHERLY PRESSURE GRADIENT INCREASES.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

$$

PUBLIC FORECAST: W PI
AVIATION/MARINE: CW

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 210544
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1044 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 9:00 PM PDT WEDNESDAY...UPPER LEVEL TROUGH JUST
WEST OF SAN FRANCISCO BROUGHT ANOTHER DAY OF COOL TEMPERATURES TO
THE AREA. STRATUS BURNED OFF IN SOME AREAS THIS AFTERNOON BUT OAK
SOUNDING SHOWS A DEEP MARINE LAYER AROUND 3000 FEET SO LOW CLOUDS
WILL REDEVELOP AND EXTEND WELL INLAND TONIGHT.

A STRONG DISTURBANCE APPROACHING THE BACK SIDE OF THE TROUGH WILL
INTENSIFY THE TROUGH AND PUSH IT TOWARDS SOUTHERN CALIFORNIA ON THURSDAY.
THIS WILL HELP DEEPEN THE MARINE LAYER EVEN MORE ON THURSDAY...TO
THE POINT WHERE THERE COULD BE LOCAL DRIZZLE OR LIGHT SHOWERS.
THIS ALSO RENEWS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS OVER
THE MOUNTAINS WITH THE BEST CHANCES OVER THE SAN BENITO COUNTY
MOUNTAINS. THE LATEST HRRR AND WRF MODELS SHOW SCATTERED PRECIP
AMOUNTS OF 1 TO 3 HUNDREDTHS OF AN INCH NEAR THE COAST AND LIGHT
CONVECTIVE PRECIP IN THE SAN BENITO COUNTY MOUNTAINS.

SLIGHT PRECIP CHANCES CONTINUE INTO FRIDAY AS THE LOW MOVES INLAND
OVER SOUTHERN CALIFORNIA BUT THUNDERSTORM CHANCES WILL BE
DIMINISHED ON THE BACK SIDE OF THE LOW. PRECIP CHANCES END FRIDAY
NIGHT.

PREVIOUS MODEL RUNS INDICATED AN UPPER LEVEL RIDGE BUILDING OFF
THE COAST THIS WEEKEND BUT LATEST MODELS ARE BRINGING ANOTHER
UPPER LEVEL DISTURBANCE ALONG THE BACK SIDE OF THE LOW THROUGH
THE NORTHERN CALIFORNIA INTERIOR ON SATURDAY WITH ONLY WEAK
RIDGING SUNDAY AND MONDAY. DRY WEATHER IS STILL EXPECTED AND
TEMPERATURES SHOULD STILL WARM UP SATURDAY THROUGH MONDAY BUT NOT
AS MUCH AS ORIGINALLY THOUGHT.

&&

.AVIATION...AS OF 10:44 PM PDT WEDNESDAY...LOW CLOUD ARE FILLING
IN ACROSS THE REGION WITH BORDERLINE IFR/MVFR CIGS BEING REPORTED.
ONSHORE FLOW WILL PREVAIL THROUGH TONIGHT WITH GUSTIER WINDS
FORECAST THURSDAY AFTERNOON. THE LOW SITUATED OVER THE REGION IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...BORDERLINE IFR/MVFR CIGS EXPECTED THROUGH
TONIGHT. CIGS ARE EXPECTED TO LIFT A BIT THURSDAY RESULTING IN
-DZ AND VCSH. ONSHORE FLOW WILL PREVAIL.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED THROUGH MUCH OF
THE FORECAST PERIOD. ONSHORE FLOW WILL CONTINUE. -DZ AND VCSH POSS
THURSDAY MORNING.

&&

.MARINE...AS OF 8:44 PM PDT WEDNESDAY...UNSETTLED WEATHER IS
EXPECTED OVER THE COASTAL WATERS AS A STORM SYSTEM WILL MOVE
THROUGH THE REGION THURSDAY AND FRIDAY. LIGHT TO MODERATE
NORTHERLY WINDS WILL CONTINUE AS THE STORM SYSTEM SLIDES THROUGH.
NORTHERLY WINDS WILL INCREASE FRIDAY AND OVER THE WEEKEND AS THE
NORTHERLY PRESSURE GRADIENT INCREASES.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

$$

PUBLIC FORECAST: W PI
AVIATION/MARINE: CW

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 210357
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
857 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 9:00 PM PDT WEDNESDAY...UPPER LEVEL TROUGH JUST
WEST OF SAN FRANCISCO BROUGHT ANOTHER DAY OF COOL TEMPERATURES TO
THE AREA. STRATUS BURNED OFF IN SOME AREAS THIS AFTERNOON BUT OAK
SOUNDING SHOWS A DEEP MARINE LAYER AROUND 3000 FEET SO LOW CLOUDS
WILL REDEVELOP AND EXTEND WELL INLAND TONIGHT.

A STRONG DISTURBANCE APPROACHING THE BACK SIDE OF THE TROUGH WILL
INTENSIFY THE TROUGH AND PUSH IT TOWARDS SOUTHERN CALIFORNIA ON THURSDAY.
THIS WILL HELP DEEPEN THE MARINE LAYER EVEN MORE ON THURSDAY...TO
THE POINT WHERE THERE COULD BE LOCAL DRIZZLE OR LIGHT SHOWERS.
THIS ALSO RENEWS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS OVER
THE MOUNTAINS WITH THE BEST CHANCES OVER THE SAN BENITO COUNTY
MOUNTAINS. THE LATEST HRRR AND WRF MODELS SHOW SCATTERED PRECIP
AMOUNTS OF 1 TO 3 HUNDREDTHS OF AN INCH NEAR THE COAST AND LIGHT
CONVECTIVE PRECIP IN THE SAN BENITO COUNTY MOUNTAINS.

SLIGHT PRECIP CHANCES CONTINUE INTO FRIDAY AS THE LOW MOVES INLAND
OVER SOUTHERN CALIFORNIA BUT THUNDERSTORM CHANCES WILL BE
DIMINISHED ON THE BACK SIDE OF THE LOW. PRECIP CHANCES END FRIDAY
NIGHT.

PREVIOUS MODEL RUNS INDICATED AN UPPER LEVEL RIDGE BUILDING OFF
THE COAST THIS WEEKEND BUT LATEST MODELS ARE BRINGING ANOTHER
UPPER LEVEL DISTURBANCE ALONG THE BACK SIDE OF THE LOW THROUGH
THE NORTHERN CALIFORNIA INTERIOR ON SATURDAY WITH ONLY WEAK
RIDGING SUNDAY AND MONDAY. DRY WEATHER IS STILL EXPECTED AND
TEMPERATURES SHOULD STILL WARM UP SATURDAY THROUGH MONDAY BUT NOT
AS MUCH AS ORIGINALLY THOUGHT.


&&

.AVIATION...AS OF 5:00 PM PDT WEDNESDAY...A MIX OF LOW AND MID-
LEVEL CLOUDS PREVAILS ONCE AGAIN TODAY AS A LOW PRESSURE SYSTEM
REMAINS OVER THE AREA. CLEARING IS NOT EXPECTED OVER BAY AREA
TERMINALS THIS AFTERNOON WITH CIGS EXPECTED TO FILL BACK IN THIS
EVENING AND OVERNIGHT. ONSHORE FLOW WILL PREVAIL. THE LOW IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...MVFR CIGS EXPECTED THROUGH MUCH OF THE FORECAST
PERIOD. ONSHORE FLOW WILL PREVAIL. -DZ AND VCSH POSS TOMORROW MORNING.


KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED TO RETURN THIS
EVENING AND PERSIST THROUGH MUCH OF THE FORECAST PERIOD. ONSHORE
FLOW WILL CONTINUE. -DZ AND VCSH POSS TOMORROW MORNING.

&&

.MARINE...AS OF 01:09 PM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

$$

PUBLIC FORECAST: W PI
AVIATION: CW
MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA








000
FXUS66 KMTR 210357
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
857 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.

&&

.DISCUSSION...AS OF 9:00 PM PDT WEDNESDAY...UPPER LEVEL TROUGH JUST
WEST OF SAN FRANCISCO BROUGHT ANOTHER DAY OF COOL TEMPERATURES TO
THE AREA. STRATUS BURNED OFF IN SOME AREAS THIS AFTERNOON BUT OAK
SOUNDING SHOWS A DEEP MARINE LAYER AROUND 3000 FEET SO LOW CLOUDS
WILL REDEVELOP AND EXTEND WELL INLAND TONIGHT.

A STRONG DISTURBANCE APPROACHING THE BACK SIDE OF THE TROUGH WILL
INTENSIFY THE TROUGH AND PUSH IT TOWARDS SOUTHERN CALIFORNIA ON THURSDAY.
THIS WILL HELP DEEPEN THE MARINE LAYER EVEN MORE ON THURSDAY...TO
THE POINT WHERE THERE COULD BE LOCAL DRIZZLE OR LIGHT SHOWERS.
THIS ALSO RENEWS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS OVER
THE MOUNTAINS WITH THE BEST CHANCES OVER THE SAN BENITO COUNTY
MOUNTAINS. THE LATEST HRRR AND WRF MODELS SHOW SCATTERED PRECIP
AMOUNTS OF 1 TO 3 HUNDREDTHS OF AN INCH NEAR THE COAST AND LIGHT
CONVECTIVE PRECIP IN THE SAN BENITO COUNTY MOUNTAINS.

SLIGHT PRECIP CHANCES CONTINUE INTO FRIDAY AS THE LOW MOVES INLAND
OVER SOUTHERN CALIFORNIA BUT THUNDERSTORM CHANCES WILL BE
DIMINISHED ON THE BACK SIDE OF THE LOW. PRECIP CHANCES END FRIDAY
NIGHT.

PREVIOUS MODEL RUNS INDICATED AN UPPER LEVEL RIDGE BUILDING OFF
THE COAST THIS WEEKEND BUT LATEST MODELS ARE BRINGING ANOTHER
UPPER LEVEL DISTURBANCE ALONG THE BACK SIDE OF THE LOW THROUGH
THE NORTHERN CALIFORNIA INTERIOR ON SATURDAY WITH ONLY WEAK
RIDGING SUNDAY AND MONDAY. DRY WEATHER IS STILL EXPECTED AND
TEMPERATURES SHOULD STILL WARM UP SATURDAY THROUGH MONDAY BUT NOT
AS MUCH AS ORIGINALLY THOUGHT.


&&

.AVIATION...AS OF 5:00 PM PDT WEDNESDAY...A MIX OF LOW AND MID-
LEVEL CLOUDS PREVAILS ONCE AGAIN TODAY AS A LOW PRESSURE SYSTEM
REMAINS OVER THE AREA. CLEARING IS NOT EXPECTED OVER BAY AREA
TERMINALS THIS AFTERNOON WITH CIGS EXPECTED TO FILL BACK IN THIS
EVENING AND OVERNIGHT. ONSHORE FLOW WILL PREVAIL. THE LOW IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...MVFR CIGS EXPECTED THROUGH MUCH OF THE FORECAST
PERIOD. ONSHORE FLOW WILL PREVAIL. -DZ AND VCSH POSS TOMORROW MORNING.


KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED TO RETURN THIS
EVENING AND PERSIST THROUGH MUCH OF THE FORECAST PERIOD. ONSHORE
FLOW WILL CONTINUE. -DZ AND VCSH POSS TOMORROW MORNING.

&&

.MARINE...AS OF 01:09 PM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

$$

PUBLIC FORECAST: W PI
AVIATION: CW
MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 210035
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
535 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 2:40 PM PDT WEDNESDAY...INLAND AREAS ARE
STARTING TO SEE PARTLY SUNNY SKIES...HOWEVER LOW CLOUDS HAVE BEEN
SLOW TO CLEAR OVER PORTIONS OF THE DISTRICT THIS AFTERNOON...AND
THE SAN FRANCISCO PENINSULA IS STILL OVERCAST. 24 HOUR TEMPERATURE
TRENDS SHOW LITTLE CHANGE COMPARED TO YESTERDAY AT THIS TIME WITH
READINGS RANGING FROM THE UPPER 50S TO THE MID 60S. LIGHTNING
DETECTION NETWORKS HAVE PICKED UP MANY LIGHTNING STRIKES ACROSS
NORTHERN AND EASTERN CALIFORNIA...NORTH AND EAST OF OUR DISTRICT.
VISIBLE SATELLITE IMAGERY SHOWS CUMULUS CLOUD BUILDUPS NOW OVER
THE HIGHER TERRAIN OF SAN BENITO COUNTY...AS WELL AS OVER THE
SANTA LUCIAS. A FEW SHOWERS ARE POSSIBLE THIS EVENING IN THESE AREAS.

LITTLE CHANGE IS EXPECTED IN THE OVERALL PATTERN THROUGH FRIDAY
AS A BROAD LONG-WAVE TROUGH WILL REMAIN OVER THE WEST COAST.
SHORT-WAVE IMPULSES ARE FORECAST TO ROTATE THROUGH THE TROUGH...AND
WILL WILL PROVIDE THE INSTABILITY FOR SHOWER CHANCES THROUGH
FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR EASTERN
SECTIONS IN THE AFTERNOON AND EVENING HOURS. THE AREAL EXTENT OF
THE SHOWER ACTIVITY IS DIFFICULT TO PINPOINT...THUS A BROAD
BRUSHED APPROACH WAS TAKEN.

BY THE WEEKEND...A UPPER LEVEL RIDGE IS PROGGED TO BUILD ALONG
THE WEST COAST DURING THE WEEKEND. THIS WILL USHER IN WARMER
TEMPERATURES SUNDAY. ANOTHER LOW PRESSURE TROUGH OVER THE GREAT
BASIN BY EARLY NEXT WEEK WILL PUSH THE UPPER RIDGE WESTWARD OVER
THE PACIFIC. THUS...TEMPERATURES WILL REMAIN AROUND NORMAL...OR
SLIGHTLY BELOW NORMAL THROUGH NEXT WEEK. PRECIPITATION CHANCES
WILL REMAIN EAST OF OUR FORECAST AREA.

&&

.AVIATION...AS OF 5:00 PM PDT WEDNESDAY...A MIX OF LOW AND MID-
LEVEL CLOUDS PREVAILS ONCE AGAIN TODAY AS A LOW PRESSURE SYSTEM
REMAINS OVER THE AREA. CLEARING IS NOT EXPECTED OVER BAY AREA
TERMINALS THIS AFTERNOON WITH CIGS EXPECTED TO FILL BACK IN THIS
EVENING AND OVERNIGHT. ONSHORE FLOW WILL PREVAIL. THE LOW IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...MVFR CIGS EXPECTED THROUGH MUCH OF THE FORECAST
PERIOD. ONSHORE FLOW WILL PREVAIL. -DZ AND VCSH POSS TOMORROW MORNING.


KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED TO RETURN THIS
EVENING AND PERSIST THROUGH MUCH OF THE FORECAST PERIOD. ONSHORE
FLOW WILL CONTINUE. -DZ AND VCSH POSS TOMORROW MORNING.

&&

.MARINE...AS OF 01:09 PM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: CW
MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 210035
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
535 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 2:40 PM PDT WEDNESDAY...INLAND AREAS ARE
STARTING TO SEE PARTLY SUNNY SKIES...HOWEVER LOW CLOUDS HAVE BEEN
SLOW TO CLEAR OVER PORTIONS OF THE DISTRICT THIS AFTERNOON...AND
THE SAN FRANCISCO PENINSULA IS STILL OVERCAST. 24 HOUR TEMPERATURE
TRENDS SHOW LITTLE CHANGE COMPARED TO YESTERDAY AT THIS TIME WITH
READINGS RANGING FROM THE UPPER 50S TO THE MID 60S. LIGHTNING
DETECTION NETWORKS HAVE PICKED UP MANY LIGHTNING STRIKES ACROSS
NORTHERN AND EASTERN CALIFORNIA...NORTH AND EAST OF OUR DISTRICT.
VISIBLE SATELLITE IMAGERY SHOWS CUMULUS CLOUD BUILDUPS NOW OVER
THE HIGHER TERRAIN OF SAN BENITO COUNTY...AS WELL AS OVER THE
SANTA LUCIAS. A FEW SHOWERS ARE POSSIBLE THIS EVENING IN THESE AREAS.

LITTLE CHANGE IS EXPECTED IN THE OVERALL PATTERN THROUGH FRIDAY
AS A BROAD LONG-WAVE TROUGH WILL REMAIN OVER THE WEST COAST.
SHORT-WAVE IMPULSES ARE FORECAST TO ROTATE THROUGH THE TROUGH...AND
WILL WILL PROVIDE THE INSTABILITY FOR SHOWER CHANCES THROUGH
FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR EASTERN
SECTIONS IN THE AFTERNOON AND EVENING HOURS. THE AREAL EXTENT OF
THE SHOWER ACTIVITY IS DIFFICULT TO PINPOINT...THUS A BROAD
BRUSHED APPROACH WAS TAKEN.

BY THE WEEKEND...A UPPER LEVEL RIDGE IS PROGGED TO BUILD ALONG
THE WEST COAST DURING THE WEEKEND. THIS WILL USHER IN WARMER
TEMPERATURES SUNDAY. ANOTHER LOW PRESSURE TROUGH OVER THE GREAT
BASIN BY EARLY NEXT WEEK WILL PUSH THE UPPER RIDGE WESTWARD OVER
THE PACIFIC. THUS...TEMPERATURES WILL REMAIN AROUND NORMAL...OR
SLIGHTLY BELOW NORMAL THROUGH NEXT WEEK. PRECIPITATION CHANCES
WILL REMAIN EAST OF OUR FORECAST AREA.

&&

.AVIATION...AS OF 5:00 PM PDT WEDNESDAY...A MIX OF LOW AND MID-
LEVEL CLOUDS PREVAILS ONCE AGAIN TODAY AS A LOW PRESSURE SYSTEM
REMAINS OVER THE AREA. CLEARING IS NOT EXPECTED OVER BAY AREA
TERMINALS THIS AFTERNOON WITH CIGS EXPECTED TO FILL BACK IN THIS
EVENING AND OVERNIGHT. ONSHORE FLOW WILL PREVAIL. THE LOW IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...MVFR CIGS EXPECTED THROUGH MUCH OF THE FORECAST
PERIOD. ONSHORE FLOW WILL PREVAIL. -DZ AND VCSH POSS TOMORROW MORNING.


KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED TO RETURN THIS
EVENING AND PERSIST THROUGH MUCH OF THE FORECAST PERIOD. ONSHORE
FLOW WILL CONTINUE. -DZ AND VCSH POSS TOMORROW MORNING.

&&

.MARINE...AS OF 01:09 PM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: CW
MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






000
FXUS66 KMTR 210035
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
535 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 2:40 PM PDT WEDNESDAY...INLAND AREAS ARE
STARTING TO SEE PARTLY SUNNY SKIES...HOWEVER LOW CLOUDS HAVE BEEN
SLOW TO CLEAR OVER PORTIONS OF THE DISTRICT THIS AFTERNOON...AND
THE SAN FRANCISCO PENINSULA IS STILL OVERCAST. 24 HOUR TEMPERATURE
TRENDS SHOW LITTLE CHANGE COMPARED TO YESTERDAY AT THIS TIME WITH
READINGS RANGING FROM THE UPPER 50S TO THE MID 60S. LIGHTNING
DETECTION NETWORKS HAVE PICKED UP MANY LIGHTNING STRIKES ACROSS
NORTHERN AND EASTERN CALIFORNIA...NORTH AND EAST OF OUR DISTRICT.
VISIBLE SATELLITE IMAGERY SHOWS CUMULUS CLOUD BUILDUPS NOW OVER
THE HIGHER TERRAIN OF SAN BENITO COUNTY...AS WELL AS OVER THE
SANTA LUCIAS. A FEW SHOWERS ARE POSSIBLE THIS EVENING IN THESE AREAS.

LITTLE CHANGE IS EXPECTED IN THE OVERALL PATTERN THROUGH FRIDAY
AS A BROAD LONG-WAVE TROUGH WILL REMAIN OVER THE WEST COAST.
SHORT-WAVE IMPULSES ARE FORECAST TO ROTATE THROUGH THE TROUGH...AND
WILL WILL PROVIDE THE INSTABILITY FOR SHOWER CHANCES THROUGH
FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR EASTERN
SECTIONS IN THE AFTERNOON AND EVENING HOURS. THE AREAL EXTENT OF
THE SHOWER ACTIVITY IS DIFFICULT TO PINPOINT...THUS A BROAD
BRUSHED APPROACH WAS TAKEN.

BY THE WEEKEND...A UPPER LEVEL RIDGE IS PROGGED TO BUILD ALONG
THE WEST COAST DURING THE WEEKEND. THIS WILL USHER IN WARMER
TEMPERATURES SUNDAY. ANOTHER LOW PRESSURE TROUGH OVER THE GREAT
BASIN BY EARLY NEXT WEEK WILL PUSH THE UPPER RIDGE WESTWARD OVER
THE PACIFIC. THUS...TEMPERATURES WILL REMAIN AROUND NORMAL...OR
SLIGHTLY BELOW NORMAL THROUGH NEXT WEEK. PRECIPITATION CHANCES
WILL REMAIN EAST OF OUR FORECAST AREA.

&&

.AVIATION...AS OF 5:00 PM PDT WEDNESDAY...A MIX OF LOW AND MID-
LEVEL CLOUDS PREVAILS ONCE AGAIN TODAY AS A LOW PRESSURE SYSTEM
REMAINS OVER THE AREA. CLEARING IS NOT EXPECTED OVER BAY AREA
TERMINALS THIS AFTERNOON WITH CIGS EXPECTED TO FILL BACK IN THIS
EVENING AND OVERNIGHT. ONSHORE FLOW WILL PREVAIL. THE LOW IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...MVFR CIGS EXPECTED THROUGH MUCH OF THE FORECAST
PERIOD. ONSHORE FLOW WILL PREVAIL. -DZ AND VCSH POSS TOMORROW MORNING.


KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED TO RETURN THIS
EVENING AND PERSIST THROUGH MUCH OF THE FORECAST PERIOD. ONSHORE
FLOW WILL CONTINUE. -DZ AND VCSH POSS TOMORROW MORNING.

&&

.MARINE...AS OF 01:09 PM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: CW
MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 210035
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
535 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 2:40 PM PDT WEDNESDAY...INLAND AREAS ARE
STARTING TO SEE PARTLY SUNNY SKIES...HOWEVER LOW CLOUDS HAVE BEEN
SLOW TO CLEAR OVER PORTIONS OF THE DISTRICT THIS AFTERNOON...AND
THE SAN FRANCISCO PENINSULA IS STILL OVERCAST. 24 HOUR TEMPERATURE
TRENDS SHOW LITTLE CHANGE COMPARED TO YESTERDAY AT THIS TIME WITH
READINGS RANGING FROM THE UPPER 50S TO THE MID 60S. LIGHTNING
DETECTION NETWORKS HAVE PICKED UP MANY LIGHTNING STRIKES ACROSS
NORTHERN AND EASTERN CALIFORNIA...NORTH AND EAST OF OUR DISTRICT.
VISIBLE SATELLITE IMAGERY SHOWS CUMULUS CLOUD BUILDUPS NOW OVER
THE HIGHER TERRAIN OF SAN BENITO COUNTY...AS WELL AS OVER THE
SANTA LUCIAS. A FEW SHOWERS ARE POSSIBLE THIS EVENING IN THESE AREAS.

LITTLE CHANGE IS EXPECTED IN THE OVERALL PATTERN THROUGH FRIDAY
AS A BROAD LONG-WAVE TROUGH WILL REMAIN OVER THE WEST COAST.
SHORT-WAVE IMPULSES ARE FORECAST TO ROTATE THROUGH THE TROUGH...AND
WILL WILL PROVIDE THE INSTABILITY FOR SHOWER CHANCES THROUGH
FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR EASTERN
SECTIONS IN THE AFTERNOON AND EVENING HOURS. THE AREAL EXTENT OF
THE SHOWER ACTIVITY IS DIFFICULT TO PINPOINT...THUS A BROAD
BRUSHED APPROACH WAS TAKEN.

BY THE WEEKEND...A UPPER LEVEL RIDGE IS PROGGED TO BUILD ALONG
THE WEST COAST DURING THE WEEKEND. THIS WILL USHER IN WARMER
TEMPERATURES SUNDAY. ANOTHER LOW PRESSURE TROUGH OVER THE GREAT
BASIN BY EARLY NEXT WEEK WILL PUSH THE UPPER RIDGE WESTWARD OVER
THE PACIFIC. THUS...TEMPERATURES WILL REMAIN AROUND NORMAL...OR
SLIGHTLY BELOW NORMAL THROUGH NEXT WEEK. PRECIPITATION CHANCES
WILL REMAIN EAST OF OUR FORECAST AREA.

&&

.AVIATION...AS OF 5:00 PM PDT WEDNESDAY...A MIX OF LOW AND MID-
LEVEL CLOUDS PREVAILS ONCE AGAIN TODAY AS A LOW PRESSURE SYSTEM
REMAINS OVER THE AREA. CLEARING IS NOT EXPECTED OVER BAY AREA
TERMINALS THIS AFTERNOON WITH CIGS EXPECTED TO FILL BACK IN THIS
EVENING AND OVERNIGHT. ONSHORE FLOW WILL PREVAIL. THE LOW IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.

VICINITY OF KSFO...MVFR CIGS EXPECTED THROUGH MUCH OF THE FORECAST
PERIOD. ONSHORE FLOW WILL PREVAIL. -DZ AND VCSH POSS TOMORROW MORNING.


KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED TO RETURN THIS
EVENING AND PERSIST THROUGH MUCH OF THE FORECAST PERIOD. ONSHORE
FLOW WILL CONTINUE. -DZ AND VCSH POSS TOMORROW MORNING.

&&

.MARINE...AS OF 01:09 PM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: CW
MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 202140
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
240 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 2:40 PM PDT WEDNESDAY...INLAND AREAS ARE
STARTING TO SEE PARTLY SUNNY SKIES...HOWEVER LOW CLOUDS HAVE BEEN
SLOW TO CLEAR OVER PORTIONS OF THE DISTRICT THIS AFTERNOON...AND
THE SAN FRANCISCO PENINSULA IS STILL OVERCAST. 24 HOUR TEMPERATURE
TRENDS SHOW LITTLE CHANGE COMPARED TO YESTERDAY AT THIS TIME WITH
READINGS RANGING FROM THE UPPER 50S TO THE MID 60S. LIGHTNING
DETECTION NETWORKS HAVE PICKED UP MANY LIGHTNING STRIKES ACROSS
NORTHERN AND EASTERN CALIFORNIA...NORTH AND EAST OF OUR DISTRICT.
VISIBLE SATELLITE IMAGERY SHOWS CUMULUS CLOUD BUILDUPS NOW OVER
THE HIGHER TERRAIN OF SAN BENITO COUNTY...AS WELL AS OVER THE
SANTA LUCIAS. A FEW SHOWERS ARE POSSIBLE THIS EVENING IN THESE AREAS.

LITTLE CHANGE IS EXPECTED IN THE OVERALL PATTERN THROUGH FRIDAY
AS A BROAD LONG-WAVE TROUGH WILL REMAIN OVER THE WEST COAST.
SHORT-WAVE IMPULSES ARE FORECAST TO ROTATE THROUGH THE TROUGH...AND
WILL WILL PROVIDE THE INSTABILITY FOR SHOWER CHANCES THROUGH
FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR EASTERN
SECTIONS IN THE AFTERNOON AND EVENING HOURS. THE AREAL EXTENT OF
THE SHOWER ACTIVITY IS DIFFICULT TO PINPOINT...THUS A BROAD
BRUSHED APPROACH WAS TAKEN.

BY THE WEEKEND...A UPPER LEVEL RIDGE IS PROGGED TO BUILD ALONG
THE WEST COAST DURING THE WEEKEND. THIS WILL USHER IN WARMER
TEMPERATURES SUNDAY. ANOTHER LOW PRESSURE TROUGH OVER THE GREAT
BASIN BY EARLY NEXT WEEK WILL PUSH THE UPPER RIDGE WESTWARD OVER
THE PACIFIC. THUS...TEMPERATURES WILL REMAIN AROUND NORMAL...OR
SLIGHTLY BELOW NORMAL THROUGH NEXT WEEK. PRECIPITATION CHANCES
WILL REMAIN EAST OF OUR FORECAST AREA.

&&

.AVIATION...AS OF 10:58 AM PDT WEDNESDAY...ATYPICAL STRATUS DECK FOR
THE BAY AREA THIS MORNING. NOT A CLASSIC MARINE LAYER MAKING IT
DIFFICULT TO FINE TUNE THE DETAILS. REGARDLESS...CONF IS PRETTY
HIGH FOR DECENT CLOUD COVER TODAY FOR ALL TERMINALS WITH MVFR CONDITIONS.
SOME CLEARING IS POSSIBLE LATER TODAY...BUT NOT THAT LIKELY FOR SF
BAY AND COAST. MARINE LAYER FILLS BACK IN TONIGHT AS AN UPPER LOW
SLIDES DOWN THE COAST. THE PASSING LOW WILL HELP TO LIFT CIGS
TOMORROW MORNING WITH SCATTERED SHOWERS. GIVEN THE UNCERTAINTY ON
COVERAGE/LOCATION OF SHOWERS DECIDED TO GO WITH VCSH AND REMOVE
SPECIFIC SHRA MENTION. OVER CONF MEDIUM.

VICINITY OF KSFO...MVFR CIGS FOR MUCH OF THE FORECAST. THE TRICKY
PART WILL BE THE EXACT CIG HEIGHT. CIGS WILL CONTINUE TO HOVER
AROUND 1600 FEET AT LEAST THROUGH THIS MORNING. EXPECT SOME
LIFTING THIS AFTERNOON AS THE LOW TRACKS CLOSER TO THE COAST AND
DAYTIME LIFTS THE CIGS.  VCSH POSS TOMORROW MORNING.


KSFO BRIDGE APPROACH...CIGS SLIGHTLY HIGHER OVER THE APPROACH
CLOSE TO 2K FT. OTHERWISE...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH THE PERIOD FOR
KMRY. KSNS COULD SEE A FEW HOURS OF VFR THIS AFTERNOON. CIGS
RETURN TONIGHT.

&&

.MARINE...AS OF 01:09 PM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA











000
FXUS66 KMTR 202140
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
240 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 2:40 PM PDT WEDNESDAY...INLAND AREAS ARE
STARTING TO SEE PARTLY SUNNY SKIES...HOWEVER LOW CLOUDS HAVE BEEN
SLOW TO CLEAR OVER PORTIONS OF THE DISTRICT THIS AFTERNOON...AND
THE SAN FRANCISCO PENINSULA IS STILL OVERCAST. 24 HOUR TEMPERATURE
TRENDS SHOW LITTLE CHANGE COMPARED TO YESTERDAY AT THIS TIME WITH
READINGS RANGING FROM THE UPPER 50S TO THE MID 60S. LIGHTNING
DETECTION NETWORKS HAVE PICKED UP MANY LIGHTNING STRIKES ACROSS
NORTHERN AND EASTERN CALIFORNIA...NORTH AND EAST OF OUR DISTRICT.
VISIBLE SATELLITE IMAGERY SHOWS CUMULUS CLOUD BUILDUPS NOW OVER
THE HIGHER TERRAIN OF SAN BENITO COUNTY...AS WELL AS OVER THE
SANTA LUCIAS. A FEW SHOWERS ARE POSSIBLE THIS EVENING IN THESE AREAS.

LITTLE CHANGE IS EXPECTED IN THE OVERALL PATTERN THROUGH FRIDAY
AS A BROAD LONG-WAVE TROUGH WILL REMAIN OVER THE WEST COAST.
SHORT-WAVE IMPULSES ARE FORECAST TO ROTATE THROUGH THE TROUGH...AND
WILL WILL PROVIDE THE INSTABILITY FOR SHOWER CHANCES THROUGH
FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR EASTERN
SECTIONS IN THE AFTERNOON AND EVENING HOURS. THE AREAL EXTENT OF
THE SHOWER ACTIVITY IS DIFFICULT TO PINPOINT...THUS A BROAD
BRUSHED APPROACH WAS TAKEN.

BY THE WEEKEND...A UPPER LEVEL RIDGE IS PROGGED TO BUILD ALONG
THE WEST COAST DURING THE WEEKEND. THIS WILL USHER IN WARMER
TEMPERATURES SUNDAY. ANOTHER LOW PRESSURE TROUGH OVER THE GREAT
BASIN BY EARLY NEXT WEEK WILL PUSH THE UPPER RIDGE WESTWARD OVER
THE PACIFIC. THUS...TEMPERATURES WILL REMAIN AROUND NORMAL...OR
SLIGHTLY BELOW NORMAL THROUGH NEXT WEEK. PRECIPITATION CHANCES
WILL REMAIN EAST OF OUR FORECAST AREA.

&&

.AVIATION...AS OF 10:58 AM PDT WEDNESDAY...ATYPICAL STRATUS DECK FOR
THE BAY AREA THIS MORNING. NOT A CLASSIC MARINE LAYER MAKING IT
DIFFICULT TO FINE TUNE THE DETAILS. REGARDLESS...CONF IS PRETTY
HIGH FOR DECENT CLOUD COVER TODAY FOR ALL TERMINALS WITH MVFR CONDITIONS.
SOME CLEARING IS POSSIBLE LATER TODAY...BUT NOT THAT LIKELY FOR SF
BAY AND COAST. MARINE LAYER FILLS BACK IN TONIGHT AS AN UPPER LOW
SLIDES DOWN THE COAST. THE PASSING LOW WILL HELP TO LIFT CIGS
TOMORROW MORNING WITH SCATTERED SHOWERS. GIVEN THE UNCERTAINTY ON
COVERAGE/LOCATION OF SHOWERS DECIDED TO GO WITH VCSH AND REMOVE
SPECIFIC SHRA MENTION. OVER CONF MEDIUM.

VICINITY OF KSFO...MVFR CIGS FOR MUCH OF THE FORECAST. THE TRICKY
PART WILL BE THE EXACT CIG HEIGHT. CIGS WILL CONTINUE TO HOVER
AROUND 1600 FEET AT LEAST THROUGH THIS MORNING. EXPECT SOME
LIFTING THIS AFTERNOON AS THE LOW TRACKS CLOSER TO THE COAST AND
DAYTIME LIFTS THE CIGS.  VCSH POSS TOMORROW MORNING.


KSFO BRIDGE APPROACH...CIGS SLIGHTLY HIGHER OVER THE APPROACH
CLOSE TO 2K FT. OTHERWISE...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH THE PERIOD FOR
KMRY. KSNS COULD SEE A FEW HOURS OF VFR THIS AFTERNOON. CIGS
RETURN TONIGHT.

&&

.MARINE...AS OF 01:09 PM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA










000
FXUS66 KMTR 202140
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
240 PM PDT WED MAY 20 2015

.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 2:40 PM PDT WEDNESDAY...INLAND AREAS ARE
STARTING TO SEE PARTLY SUNNY SKIES...HOWEVER LOW CLOUDS HAVE BEEN
SLOW TO CLEAR OVER PORTIONS OF THE DISTRICT THIS AFTERNOON...AND
THE SAN FRANCISCO PENINSULA IS STILL OVERCAST. 24 HOUR TEMPERATURE
TRENDS SHOW LITTLE CHANGE COMPARED TO YESTERDAY AT THIS TIME WITH
READINGS RANGING FROM THE UPPER 50S TO THE MID 60S. LIGHTNING
DETECTION NETWORKS HAVE PICKED UP MANY LIGHTNING STRIKES ACROSS
NORTHERN AND EASTERN CALIFORNIA...NORTH AND EAST OF OUR DISTRICT.
VISIBLE SATELLITE IMAGERY SHOWS CUMULUS CLOUD BUILDUPS NOW OVER
THE HIGHER TERRAIN OF SAN BENITO COUNTY...AS WELL AS OVER THE
SANTA LUCIAS. A FEW SHOWERS ARE POSSIBLE THIS EVENING IN THESE AREAS.

LITTLE CHANGE IS EXPECTED IN THE OVERALL PATTERN THROUGH FRIDAY
AS A BROAD LONG-WAVE TROUGH WILL REMAIN OVER THE WEST COAST.
SHORT-WAVE IMPULSES ARE FORECAST TO ROTATE THROUGH THE TROUGH...AND
WILL WILL PROVIDE THE INSTABILITY FOR SHOWER CHANCES THROUGH
FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR EASTERN
SECTIONS IN THE AFTERNOON AND EVENING HOURS. THE AREAL EXTENT OF
THE SHOWER ACTIVITY IS DIFFICULT TO PINPOINT...THUS A BROAD
BRUSHED APPROACH WAS TAKEN.

BY THE WEEKEND...A UPPER LEVEL RIDGE IS PROGGED TO BUILD ALONG
THE WEST COAST DURING THE WEEKEND. THIS WILL USHER IN WARMER
TEMPERATURES SUNDAY. ANOTHER LOW PRESSURE TROUGH OVER THE GREAT
BASIN BY EARLY NEXT WEEK WILL PUSH THE UPPER RIDGE WESTWARD OVER
THE PACIFIC. THUS...TEMPERATURES WILL REMAIN AROUND NORMAL...OR
SLIGHTLY BELOW NORMAL THROUGH NEXT WEEK. PRECIPITATION CHANCES
WILL REMAIN EAST OF OUR FORECAST AREA.

&&

.AVIATION...AS OF 10:58 AM PDT WEDNESDAY...ATYPICAL STRATUS DECK FOR
THE BAY AREA THIS MORNING. NOT A CLASSIC MARINE LAYER MAKING IT
DIFFICULT TO FINE TUNE THE DETAILS. REGARDLESS...CONF IS PRETTY
HIGH FOR DECENT CLOUD COVER TODAY FOR ALL TERMINALS WITH MVFR CONDITIONS.
SOME CLEARING IS POSSIBLE LATER TODAY...BUT NOT THAT LIKELY FOR SF
BAY AND COAST. MARINE LAYER FILLS BACK IN TONIGHT AS AN UPPER LOW
SLIDES DOWN THE COAST. THE PASSING LOW WILL HELP TO LIFT CIGS
TOMORROW MORNING WITH SCATTERED SHOWERS. GIVEN THE UNCERTAINTY ON
COVERAGE/LOCATION OF SHOWERS DECIDED TO GO WITH VCSH AND REMOVE
SPECIFIC SHRA MENTION. OVER CONF MEDIUM.

VICINITY OF KSFO...MVFR CIGS FOR MUCH OF THE FORECAST. THE TRICKY
PART WILL BE THE EXACT CIG HEIGHT. CIGS WILL CONTINUE TO HOVER
AROUND 1600 FEET AT LEAST THROUGH THIS MORNING. EXPECT SOME
LIFTING THIS AFTERNOON AS THE LOW TRACKS CLOSER TO THE COAST AND
DAYTIME LIFTS THE CIGS.  VCSH POSS TOMORROW MORNING.


KSFO BRIDGE APPROACH...CIGS SLIGHTLY HIGHER OVER THE APPROACH
CLOSE TO 2K FT. OTHERWISE...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH THE PERIOD FOR
KMRY. KSNS COULD SEE A FEW HOURS OF VFR THIS AFTERNOON. CIGS
RETURN TONIGHT.

&&

.MARINE...AS OF 01:09 PM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA











000
FXUS66 KMTR 201759
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1059 AM PDT WED MAY 20 2015

.SYNOPSIS...COOLER THAN NORMAL WEATHER WILL CONTINUE ALONG WITH A
SLIGHT CHANCE FOR SHOWERS THROUGH THE REST OF THE WORK WEEK.
SLIGHT WARMING CAN BE EXPECTED OVER THE WEEKEND INTO NEXT WEEK AS
A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 8:40 AM PDT WEDNESDAY...VISIBLE SATELLITE
IMAGERY SHOWS MARINE STRATUS CLOUDS FILLING ALL INTERIOR VALLEYS
BELOW 2000-3000 FEET. EXPECT CLOUDY TO MOSTLY CLOUDY CONDITIONS TO
PERSIST THROUGH THE MORNING AND INTO THE EARLY AFTERNOON NEAR THE
COAST. AN AREA OF LOW PRESSURE IS OVER THE WEST COAST AND LIGHT
SHOWERS OR DRIZZLE IS POSSIBLE THROUGH THE MORNING HOURS.
TEMPERATURES ARE EXPECTED TO REMAIN COOL ACROSS THE DISTRICT
THROUGH THE WORK WEEK AS THIS AREA OF LOW PRESSURE REMAINS IN
PLACE. HIGHS WILL RANGE FROM THE MID TO UPPER 50S AT THE COAST TO
THE 60S TO LOWER 70S INLAND.

OVERALL SYNOPTIC PATTERN WILL SHOW LITTLE CHANGE THROUGH FRIDAY
AS A BROAD LONGWAVE TROF WILL REMAIN OVERHEAD. SHORT-WAVE IMPULSES
ROTATING THROUGH THE TROUGH WILL PROVIDE INSTABILITY FOR SHOWERS
THROUGH FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR
EASTERN SECTIONS IN THE AFTERNOONS.

A UPPER LEVEL RIDGE WILL BUILD ALONG THE WEST COAST DURING THE
WEEKEND AND SLOWLY MOVE EASTWARD OVER CALIFORNIA. THIS WILL BRING
WARMER TEMPERATURES TO THE DISTRICT BY SUNDAY. WEAK RIDGING OVER
THE STATE WILL KEEP TEMPERATURES NEAR OR SLIGHTLY-BELOW NORMAL
INTO NEXT WEEK.

&&

.AVIATION...AS OF 10:58 AM PDT WEDNESDAY...ATYPICAL STRATUS DECK FOR
THE BAY AREA THIS MORNING. NOT A CLASSIC MARINE LAYER MAKING IT
DIFFICULT TO FINE TUNE THE DETAILS. REGARDLESS...CONF IS PRETTY
HIGH FOR DECENT CLOUD COVER TODAY FOR ALL TERMINALS WITH MVFR CONDITIONS.
SOME CLEARING IS POSSIBLE LATER TODAY...BUT NOT THAT LIKELY FOR SF
BAY AND COAST. MARINE LAYER FILLS BACK IN TONIGHT AS AN UPPER LOW
SLIDES DOWN THE COAST. THE PASSING LOW WILL HELP TO LIFT CIGS
TOMORROW MORNING WITH SCATTERED SHOWERS. GIVEN THE UNCERTAINTY ON
COVERAGE/LOCATION OF SHOWERS DECIDED TO GO WITH VCSH AND REMOVE
SPECIFIC SHRA MENTION. OVER CONF MEDIUM.

VICINITY OF KSFO...MVFR CIGS FOR MUCH OF THE FORECAST. THE TRICKY
PART WILL BE THE EXACT CIG HEIGHT. CIGS WILL CONTINUE TO HOVER
AROUND 1600 FEET AT LEAST THROUGH THIS MORNING. EXPECT SOME
LIFTING THIS AFTERNOON AS THE LOW TRACKS CLOSER TO THE COAST AND
DAYTIME LIFTS THE CIGS.  VCSH POSS TOMORROW MORNING.


KSFO BRIDGE APPROACH...CIGS SLIGHTLY HIGHER OVER THE APPROACH
CLOSE TO 2K FT. OTHERWISE...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH THE PERIOD FOR
KMRY. KSNS COULD SEE A FEW HOURS OF VFR THIS AFTERNOON. CIGS
RETURN TONIGHT.



&&

.MARINE...AS OF 8:25 AM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM NOON

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA








000
FXUS66 KMTR 201759
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1059 AM PDT WED MAY 20 2015

.SYNOPSIS...COOLER THAN NORMAL WEATHER WILL CONTINUE ALONG WITH A
SLIGHT CHANCE FOR SHOWERS THROUGH THE REST OF THE WORK WEEK.
SLIGHT WARMING CAN BE EXPECTED OVER THE WEEKEND INTO NEXT WEEK AS
A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 8:40 AM PDT WEDNESDAY...VISIBLE SATELLITE
IMAGERY SHOWS MARINE STRATUS CLOUDS FILLING ALL INTERIOR VALLEYS
BELOW 2000-3000 FEET. EXPECT CLOUDY TO MOSTLY CLOUDY CONDITIONS TO
PERSIST THROUGH THE MORNING AND INTO THE EARLY AFTERNOON NEAR THE
COAST. AN AREA OF LOW PRESSURE IS OVER THE WEST COAST AND LIGHT
SHOWERS OR DRIZZLE IS POSSIBLE THROUGH THE MORNING HOURS.
TEMPERATURES ARE EXPECTED TO REMAIN COOL ACROSS THE DISTRICT
THROUGH THE WORK WEEK AS THIS AREA OF LOW PRESSURE REMAINS IN
PLACE. HIGHS WILL RANGE FROM THE MID TO UPPER 50S AT THE COAST TO
THE 60S TO LOWER 70S INLAND.

OVERALL SYNOPTIC PATTERN WILL SHOW LITTLE CHANGE THROUGH FRIDAY
AS A BROAD LONGWAVE TROF WILL REMAIN OVERHEAD. SHORT-WAVE IMPULSES
ROTATING THROUGH THE TROUGH WILL PROVIDE INSTABILITY FOR SHOWERS
THROUGH FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR
EASTERN SECTIONS IN THE AFTERNOONS.

A UPPER LEVEL RIDGE WILL BUILD ALONG THE WEST COAST DURING THE
WEEKEND AND SLOWLY MOVE EASTWARD OVER CALIFORNIA. THIS WILL BRING
WARMER TEMPERATURES TO THE DISTRICT BY SUNDAY. WEAK RIDGING OVER
THE STATE WILL KEEP TEMPERATURES NEAR OR SLIGHTLY-BELOW NORMAL
INTO NEXT WEEK.

&&

.AVIATION...AS OF 10:58 AM PDT WEDNESDAY...ATYPICAL STRATUS DECK FOR
THE BAY AREA THIS MORNING. NOT A CLASSIC MARINE LAYER MAKING IT
DIFFICULT TO FINE TUNE THE DETAILS. REGARDLESS...CONF IS PRETTY
HIGH FOR DECENT CLOUD COVER TODAY FOR ALL TERMINALS WITH MVFR CONDITIONS.
SOME CLEARING IS POSSIBLE LATER TODAY...BUT NOT THAT LIKELY FOR SF
BAY AND COAST. MARINE LAYER FILLS BACK IN TONIGHT AS AN UPPER LOW
SLIDES DOWN THE COAST. THE PASSING LOW WILL HELP TO LIFT CIGS
TOMORROW MORNING WITH SCATTERED SHOWERS. GIVEN THE UNCERTAINTY ON
COVERAGE/LOCATION OF SHOWERS DECIDED TO GO WITH VCSH AND REMOVE
SPECIFIC SHRA MENTION. OVER CONF MEDIUM.

VICINITY OF KSFO...MVFR CIGS FOR MUCH OF THE FORECAST. THE TRICKY
PART WILL BE THE EXACT CIG HEIGHT. CIGS WILL CONTINUE TO HOVER
AROUND 1600 FEET AT LEAST THROUGH THIS MORNING. EXPECT SOME
LIFTING THIS AFTERNOON AS THE LOW TRACKS CLOSER TO THE COAST AND
DAYTIME LIFTS THE CIGS.  VCSH POSS TOMORROW MORNING.


KSFO BRIDGE APPROACH...CIGS SLIGHTLY HIGHER OVER THE APPROACH
CLOSE TO 2K FT. OTHERWISE...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH THE PERIOD FOR
KMRY. KSNS COULD SEE A FEW HOURS OF VFR THIS AFTERNOON. CIGS
RETURN TONIGHT.



&&

.MARINE...AS OF 8:25 AM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM NOON

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA









000
FXUS66 KMTR 201540
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
840 AM PDT WED MAY 20 2015

.SYNOPSIS...COOLER THAN NORMAL WEATHER WILL CONTINUE ALONG WITH A
SLIGHT CHANCE FOR SHOWERS THROUGH THE REST OF THE WORK WEEK.
SLIGHT WARMING CAN BE EXPECTED OVER THE WEEKEND INTO NEXT WEEK AS
A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 8:40 AM PDT WEDNESDAY...VISIBLE SATELLITE
IMAGERY SHOWS MARINE STRATUS CLOUDS FILLING ALL INTERIOR VALLEYS
BELOW 2000-3000 FEET. EXPECT CLOUDY TO MOSTLY CLOUDY CONDITIONS TO
PERSIST THROUGH THE MORNING AND INTO THE EARLY AFTERNOON NEAR THE
COAST. AN AREA OF LOW PRESSURE IS OVER THE WEST COAST AND LIGHT
SHOWERS OR DRIZZLE IS POSSIBLE THROUGH THE MORNING HOURS.
TEMPERATURES ARE EXPECTED TO REMAIN COOL ACROSS THE DISTRICT
THROUGH THE WORK WEEK AS THIS AREA OF LOW PRESSURE REMAINS IN
PLACE. HIGHS WILL RANGE FROM THE MID TO UPPER 50S AT THE COAST TO
THE 60S TO LOWER 70S INLAND.

OVERALL SYNOPTIC PATTERN WILL SHOW LITTLE CHANGE THROUGH FRIDAY
AS A BROAD LONGWAVE TROF WILL REMAIN OVERHEAD. SHORT-WAVE IMPULSES
ROTATING THROUGH THE TROUGH WILL PROVIDE INSTABILITY FOR SHOWERS
THROUGH FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR
EASTERN SECTIONS IN THE AFTERNOONS.

A UPPER LEVEL RIDGE WILL BUILD ALONG THE WEST COAST DURING THE
WEEKEND AND SLOWLY MOVE EASTWARD OVER CALIFORNIA. THIS WILL BRING
WARMER TEMPERATURES TO THE DISTRICT BY SUNDAY. WEAK RIDGING OVER
THE STATE WILL KEEP TEMPERATURES NEAR OR SLIGHTLY-BELOW NORMAL
INTO NEXT WEEK.

&&

.AVIATION...AS OF 5:00 AM PDT WEDNESDAY...A PERSISTENT AREA OF
LOW PRESSURE POSITIONED OVER THE CALIFORNIA COAST WILL MAINTAIN
CLOUD COVER OVER THE TERMINALS THROUGH THE FORECAST PERIOD. A LOW
PRESSURE SYSTEM IS WORKING ITS WAY TOWARD THE COAST AND WILL
PROVIDE ENOUGH LIFT TO THE CLOUDS THAT DRIZZLE WILL BE A FACTOR
THIS EVENING.

VICINITY OF KSFO...MVFR CIGS ARE EXPECTED TO PREVAIL TODAY
STARTING OUT WITH BKN012 OVC020. CIGS WILL IMPROVE TO BKN-OVC022
BY AROUND 1900Z. WESTERLY WINDS 8 TO 10 KT WILL INCREASE TO AROUND
15 KT THIS AFTERNOON. DRIZZLE IS EXPECTED OVERNIGHT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS ARE EXPECTED TO PREVAIL
TODAY STARTING OUT THE DAY OVC018 IMPROVING TO BKN022-025 BY
AROUND 2000Z. DRIZZLE IS EXPECTED OVERNIGHT. WESTERLY WINDS WILL
REACH 10 TO 12 KT THIS AFTERNOON WITH GUSTS TO 18 KT POSSIBLE.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 8:25 AM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM NOON

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: LARRY
MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA










000
FXUS66 KMTR 201540
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
840 AM PDT WED MAY 20 2015

.SYNOPSIS...COOLER THAN NORMAL WEATHER WILL CONTINUE ALONG WITH A
SLIGHT CHANCE FOR SHOWERS THROUGH THE REST OF THE WORK WEEK.
SLIGHT WARMING CAN BE EXPECTED OVER THE WEEKEND INTO NEXT WEEK AS
A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 8:40 AM PDT WEDNESDAY...VISIBLE SATELLITE
IMAGERY SHOWS MARINE STRATUS CLOUDS FILLING ALL INTERIOR VALLEYS
BELOW 2000-3000 FEET. EXPECT CLOUDY TO MOSTLY CLOUDY CONDITIONS TO
PERSIST THROUGH THE MORNING AND INTO THE EARLY AFTERNOON NEAR THE
COAST. AN AREA OF LOW PRESSURE IS OVER THE WEST COAST AND LIGHT
SHOWERS OR DRIZZLE IS POSSIBLE THROUGH THE MORNING HOURS.
TEMPERATURES ARE EXPECTED TO REMAIN COOL ACROSS THE DISTRICT
THROUGH THE WORK WEEK AS THIS AREA OF LOW PRESSURE REMAINS IN
PLACE. HIGHS WILL RANGE FROM THE MID TO UPPER 50S AT THE COAST TO
THE 60S TO LOWER 70S INLAND.

OVERALL SYNOPTIC PATTERN WILL SHOW LITTLE CHANGE THROUGH FRIDAY
AS A BROAD LONGWAVE TROF WILL REMAIN OVERHEAD. SHORT-WAVE IMPULSES
ROTATING THROUGH THE TROUGH WILL PROVIDE INSTABILITY FOR SHOWERS
THROUGH FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR
EASTERN SECTIONS IN THE AFTERNOONS.

A UPPER LEVEL RIDGE WILL BUILD ALONG THE WEST COAST DURING THE
WEEKEND AND SLOWLY MOVE EASTWARD OVER CALIFORNIA. THIS WILL BRING
WARMER TEMPERATURES TO THE DISTRICT BY SUNDAY. WEAK RIDGING OVER
THE STATE WILL KEEP TEMPERATURES NEAR OR SLIGHTLY-BELOW NORMAL
INTO NEXT WEEK.

&&

.AVIATION...AS OF 5:00 AM PDT WEDNESDAY...A PERSISTENT AREA OF
LOW PRESSURE POSITIONED OVER THE CALIFORNIA COAST WILL MAINTAIN
CLOUD COVER OVER THE TERMINALS THROUGH THE FORECAST PERIOD. A LOW
PRESSURE SYSTEM IS WORKING ITS WAY TOWARD THE COAST AND WILL
PROVIDE ENOUGH LIFT TO THE CLOUDS THAT DRIZZLE WILL BE A FACTOR
THIS EVENING.

VICINITY OF KSFO...MVFR CIGS ARE EXPECTED TO PREVAIL TODAY
STARTING OUT WITH BKN012 OVC020. CIGS WILL IMPROVE TO BKN-OVC022
BY AROUND 1900Z. WESTERLY WINDS 8 TO 10 KT WILL INCREASE TO AROUND
15 KT THIS AFTERNOON. DRIZZLE IS EXPECTED OVERNIGHT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS ARE EXPECTED TO PREVAIL
TODAY STARTING OUT THE DAY OVC018 IMPROVING TO BKN022-025 BY
AROUND 2000Z. DRIZZLE IS EXPECTED OVERNIGHT. WESTERLY WINDS WILL
REACH 10 TO 12 KT THIS AFTERNOON WITH GUSTS TO 18 KT POSSIBLE.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 8:25 AM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM NOON

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: LARRY
MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA










000
FXUS66 KMTR 201540
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
840 AM PDT WED MAY 20 2015

.SYNOPSIS...COOLER THAN NORMAL WEATHER WILL CONTINUE ALONG WITH A
SLIGHT CHANCE FOR SHOWERS THROUGH THE REST OF THE WORK WEEK.
SLIGHT WARMING CAN BE EXPECTED OVER THE WEEKEND INTO NEXT WEEK AS
A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 8:40 AM PDT WEDNESDAY...VISIBLE SATELLITE
IMAGERY SHOWS MARINE STRATUS CLOUDS FILLING ALL INTERIOR VALLEYS
BELOW 2000-3000 FEET. EXPECT CLOUDY TO MOSTLY CLOUDY CONDITIONS TO
PERSIST THROUGH THE MORNING AND INTO THE EARLY AFTERNOON NEAR THE
COAST. AN AREA OF LOW PRESSURE IS OVER THE WEST COAST AND LIGHT
SHOWERS OR DRIZZLE IS POSSIBLE THROUGH THE MORNING HOURS.
TEMPERATURES ARE EXPECTED TO REMAIN COOL ACROSS THE DISTRICT
THROUGH THE WORK WEEK AS THIS AREA OF LOW PRESSURE REMAINS IN
PLACE. HIGHS WILL RANGE FROM THE MID TO UPPER 50S AT THE COAST TO
THE 60S TO LOWER 70S INLAND.

OVERALL SYNOPTIC PATTERN WILL SHOW LITTLE CHANGE THROUGH FRIDAY
AS A BROAD LONGWAVE TROF WILL REMAIN OVERHEAD. SHORT-WAVE IMPULSES
ROTATING THROUGH THE TROUGH WILL PROVIDE INSTABILITY FOR SHOWERS
THROUGH FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR
EASTERN SECTIONS IN THE AFTERNOONS.

A UPPER LEVEL RIDGE WILL BUILD ALONG THE WEST COAST DURING THE
WEEKEND AND SLOWLY MOVE EASTWARD OVER CALIFORNIA. THIS WILL BRING
WARMER TEMPERATURES TO THE DISTRICT BY SUNDAY. WEAK RIDGING OVER
THE STATE WILL KEEP TEMPERATURES NEAR OR SLIGHTLY-BELOW NORMAL
INTO NEXT WEEK.

&&

.AVIATION...AS OF 5:00 AM PDT WEDNESDAY...A PERSISTENT AREA OF
LOW PRESSURE POSITIONED OVER THE CALIFORNIA COAST WILL MAINTAIN
CLOUD COVER OVER THE TERMINALS THROUGH THE FORECAST PERIOD. A LOW
PRESSURE SYSTEM IS WORKING ITS WAY TOWARD THE COAST AND WILL
PROVIDE ENOUGH LIFT TO THE CLOUDS THAT DRIZZLE WILL BE A FACTOR
THIS EVENING.

VICINITY OF KSFO...MVFR CIGS ARE EXPECTED TO PREVAIL TODAY
STARTING OUT WITH BKN012 OVC020. CIGS WILL IMPROVE TO BKN-OVC022
BY AROUND 1900Z. WESTERLY WINDS 8 TO 10 KT WILL INCREASE TO AROUND
15 KT THIS AFTERNOON. DRIZZLE IS EXPECTED OVERNIGHT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS ARE EXPECTED TO PREVAIL
TODAY STARTING OUT THE DAY OVC018 IMPROVING TO BKN022-025 BY
AROUND 2000Z. DRIZZLE IS EXPECTED OVERNIGHT. WESTERLY WINDS WILL
REACH 10 TO 12 KT THIS AFTERNOON WITH GUSTS TO 18 KT POSSIBLE.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 8:25 AM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM NOON

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: LARRY
MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA











000
FXUS66 KMTR 201540
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
840 AM PDT WED MAY 20 2015

.SYNOPSIS...COOLER THAN NORMAL WEATHER WILL CONTINUE ALONG WITH A
SLIGHT CHANCE FOR SHOWERS THROUGH THE REST OF THE WORK WEEK.
SLIGHT WARMING CAN BE EXPECTED OVER THE WEEKEND INTO NEXT WEEK AS
A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 8:40 AM PDT WEDNESDAY...VISIBLE SATELLITE
IMAGERY SHOWS MARINE STRATUS CLOUDS FILLING ALL INTERIOR VALLEYS
BELOW 2000-3000 FEET. EXPECT CLOUDY TO MOSTLY CLOUDY CONDITIONS TO
PERSIST THROUGH THE MORNING AND INTO THE EARLY AFTERNOON NEAR THE
COAST. AN AREA OF LOW PRESSURE IS OVER THE WEST COAST AND LIGHT
SHOWERS OR DRIZZLE IS POSSIBLE THROUGH THE MORNING HOURS.
TEMPERATURES ARE EXPECTED TO REMAIN COOL ACROSS THE DISTRICT
THROUGH THE WORK WEEK AS THIS AREA OF LOW PRESSURE REMAINS IN
PLACE. HIGHS WILL RANGE FROM THE MID TO UPPER 50S AT THE COAST TO
THE 60S TO LOWER 70S INLAND.

OVERALL SYNOPTIC PATTERN WILL SHOW LITTLE CHANGE THROUGH FRIDAY
AS A BROAD LONGWAVE TROF WILL REMAIN OVERHEAD. SHORT-WAVE IMPULSES
ROTATING THROUGH THE TROUGH WILL PROVIDE INSTABILITY FOR SHOWERS
THROUGH FRIDAY...AS WELL AS ISOLATED THUNDERSTORMS ACROSS THE FAR
EASTERN SECTIONS IN THE AFTERNOONS.

A UPPER LEVEL RIDGE WILL BUILD ALONG THE WEST COAST DURING THE
WEEKEND AND SLOWLY MOVE EASTWARD OVER CALIFORNIA. THIS WILL BRING
WARMER TEMPERATURES TO THE DISTRICT BY SUNDAY. WEAK RIDGING OVER
THE STATE WILL KEEP TEMPERATURES NEAR OR SLIGHTLY-BELOW NORMAL
INTO NEXT WEEK.

&&

.AVIATION...AS OF 5:00 AM PDT WEDNESDAY...A PERSISTENT AREA OF
LOW PRESSURE POSITIONED OVER THE CALIFORNIA COAST WILL MAINTAIN
CLOUD COVER OVER THE TERMINALS THROUGH THE FORECAST PERIOD. A LOW
PRESSURE SYSTEM IS WORKING ITS WAY TOWARD THE COAST AND WILL
PROVIDE ENOUGH LIFT TO THE CLOUDS THAT DRIZZLE WILL BE A FACTOR
THIS EVENING.

VICINITY OF KSFO...MVFR CIGS ARE EXPECTED TO PREVAIL TODAY
STARTING OUT WITH BKN012 OVC020. CIGS WILL IMPROVE TO BKN-OVC022
BY AROUND 1900Z. WESTERLY WINDS 8 TO 10 KT WILL INCREASE TO AROUND
15 KT THIS AFTERNOON. DRIZZLE IS EXPECTED OVERNIGHT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS ARE EXPECTED TO PREVAIL
TODAY STARTING OUT THE DAY OVC018 IMPROVING TO BKN022-025 BY
AROUND 2000Z. DRIZZLE IS EXPECTED OVERNIGHT. WESTERLY WINDS WILL
REACH 10 TO 12 KT THIS AFTERNOON WITH GUSTS TO 18 KT POSSIBLE.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 8:25 AM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM NOON

&&

$$

PUBLIC FORECAST: SIMS
AVIATION: LARRY
MARINE: MM

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
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000
FXUS66 KMTR 201159
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
459 AM PDT WED MAY 20 2015

.SYNOPSIS...COOLER THAN NORMAL WEATHER WILL CONTINUE ALONG WITH A
SLIGHT CHANCE FOR SHOWERS THROUGH THE REST OF THE WORK WEEK.
SLIGHT WARMING CAN BE EXPECTED OVER THE WEEKEND INTO NEXT WEEK AS
A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 3:00 AM PDT WEDNESDAY...WIDESPREAD CLOUDS THIS
MORNING ACROSS OUR AREA WITH A WEAK ONSHORE FLOW ALONG WITH A
POORLY DEFINED ALBEIT DEEP MARINE LAYER. SIMILAR TO
YESTERDAY...WOULD EXPECT TO GET SOME REPORTS OF MODERATE DRIZZLE
OR RAIN LEADING TO SOME WET ROADS FOR THE MORNING COMMUTE. CLOUDS
WILL LIKELY BE SLOW TO DISSIPATE TODAY ALTHOUGH SOME BREAKS ARE
EXPECTED DOWN TO THE COAST. TEMPERATURES WILL ALSO BE SIMILAR TO
TUESDAY WITH HIGHS GENERALLY IN THE UPPER 50S TO MID 60S AT THE
COAST WHILE MID 60S TO LOWER 70S WILL BE COMMON INLAND.

OVERALL SYNOPTIC PATTERN WILL SHOW LITTLE CHANGE THROUGH FRIDAY AS
A BROAD LONGWAVE TROF WILL REMAIN OVERHEAD WHILE PIECES OF ENERGY
ROTATE THROUGH IT AND ACROSS OUR AREA. THIS WILL HELP TO KEEP
TEMPERATURES ON THE COOL SIDE PLUS PROVIDE ENOUGH INSTABILITY TO
KICK OFF A FEW SHOWERS THROUGH FRIDAY. THUNDERSTORMS CONTINUE TO BE A
POSSIBILITY OVER FAR EASTERN PORTIONS WHERE THE INSTABILITY IS THE
GREATEST AND HEATING/SUNSHINE SHOULD BE THE MOST.

A RIDGE WILL BUILD ALONG THE WEST COAST OVER THE WEEKEND AND
SLOWLY PUSH INTO OUR AREA. GUIDANCE HAS SLIGHTLY SLOWED THE
PROGRESSION OF THE RIDGE SUGGESTING THAT WARMER WEATHER COULD TAKE
AN EXTRA DAY TO ARRIVE. BY SUNDAY HIGHS WILL BE 5 TO 10 DEGREES
WARMER THAN CURRENT READINGS ALTHOUGH STILL A BIT COOLER THAN
NORMAL IN MOST SPOTS. HIGHS MAY WARM ANOTHER DEGREE OR TWO FOR
NEXT WORK WEEK AS THE RIDGE FINALLY MAKES ITS WAY INLAND.

NO SIGNS OF A SUBSTANTIAL WARM-UP THROUGH AT LEAST THE END OF NEXT
WEEK. IN FACT...LATEST OPERATIONAL RUNS OF BOTH THE ECMWF AND GFS
BRING ANOTHER LONGWAVE TROF NEAR OUR AREA FOR THE SECOND HALF OF
NEXT WEEK.
&&

.AVIATION...AS OF 5:00 AM PDT WEDNESDAY...A PERSISTENT AREA OF
LOW PRESSURE POSITIONED OVER THE CALIFORNIA COAST WILL MAINTAIN
CLOUD COVER OVER THE TERMINALS THROUGH THE FORECAST PERIOD. A LOW
PRESSURE SYSTEM IS WORKING ITS WAY TOWARD THE COAST AND WILL
PROVIDE ENOUGH LIFT TO THE CLOUDS THAT DRIZZLE WILL BE A FACTOR
THIS EVENING.

VICINITY OF KSFO...MVFR CIGS ARE EXPECTED TO PREVAIL TODAY
STARTING OUT WITH BKN012 OVC020. CIGS WILL IMPROVE TO BKN-OVC022
BY AROUND 1900Z. WESTERLY WINDS 8 TO 10 KT WILL INCREASE TO AROUND
15 KT THIS AFTERNOON. DRIZZLE IS EXPECTED OVERNIGHT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS ARE EXPECTED TO PREVAIL
TODAY STARTING OUT THE DAY OVC018 IMPROVING TO BKN022-025 BY
AROUND 2000Z. DRIZZLE IS EXPECTED OVERNIGHT. WESTERLY WINDS WILL
REACH 10 TO 12 KT THIS AFTERNOON WITH GUSTS TO 18 KT POSSIBLE.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 3:00 AM PDT WEDNESDAY...GENERALLY LIGHT WINDS AND SEAS
ARE EXPECTED THROUGH FRIDAY AS AN AREA OF LOW PRESSURE RESIDES
OVER THE CALIFORNIA COAST. A STORM SYSTEM WILL SLIDE SOUTH ALONG
THE COAST THURSDAY INCREASING THE CHANCE OF SHOWERS INTO FRIDAY.
THE SURFACE PRESSURE GRADIENT WILL STRENGTHEN FRIDAY EVENING AS
THE STORM SYSTEM MOVES OUT OF THE AREA. THE STRENGTHENING SURFACE
PRESSURE GRADIENT WILL RESULT IN INCREASING WINDS AND
DETERIORATING SEA CONDITIONS THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM NOON

&&

$$

PUBLIC FORECAST: BELL
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 201159
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
459 AM PDT WED MAY 20 2015

.SYNOPSIS...COOLER THAN NORMAL WEATHER WILL CONTINUE ALONG WITH A
SLIGHT CHANCE FOR SHOWERS THROUGH THE REST OF THE WORK WEEK.
SLIGHT WARMING CAN BE EXPECTED OVER THE WEEKEND INTO NEXT WEEK AS
A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 3:00 AM PDT WEDNESDAY...WIDESPREAD CLOUDS THIS
MORNING ACROSS OUR AREA WITH A WEAK ONSHORE FLOW ALONG WITH A
POORLY DEFINED ALBEIT DEEP MARINE LAYER. SIMILAR TO
YESTERDAY...WOULD EXPECT TO GET SOME REPORTS OF MODERATE DRIZZLE
OR RAIN LEADING TO SOME WET ROADS FOR THE MORNING COMMUTE. CLOUDS
WILL LIKELY BE SLOW TO DISSIPATE TODAY ALTHOUGH SOME BREAKS ARE
EXPECTED DOWN TO THE COAST. TEMPERATURES WILL ALSO BE SIMILAR TO
TUESDAY WITH HIGHS GENERALLY IN THE UPPER 50S TO MID 60S AT THE
COAST WHILE MID 60S TO LOWER 70S WILL BE COMMON INLAND.

OVERALL SYNOPTIC PATTERN WILL SHOW LITTLE CHANGE THROUGH FRIDAY AS
A BROAD LONGWAVE TROF WILL REMAIN OVERHEAD WHILE PIECES OF ENERGY
ROTATE THROUGH IT AND ACROSS OUR AREA. THIS WILL HELP TO KEEP
TEMPERATURES ON THE COOL SIDE PLUS PROVIDE ENOUGH INSTABILITY TO
KICK OFF A FEW SHOWERS THROUGH FRIDAY. THUNDERSTORMS CONTINUE TO BE A
POSSIBILITY OVER FAR EASTERN PORTIONS WHERE THE INSTABILITY IS THE
GREATEST AND HEATING/SUNSHINE SHOULD BE THE MOST.

A RIDGE WILL BUILD ALONG THE WEST COAST OVER THE WEEKEND AND
SLOWLY PUSH INTO OUR AREA. GUIDANCE HAS SLIGHTLY SLOWED THE
PROGRESSION OF THE RIDGE SUGGESTING THAT WARMER WEATHER COULD TAKE
AN EXTRA DAY TO ARRIVE. BY SUNDAY HIGHS WILL BE 5 TO 10 DEGREES
WARMER THAN CURRENT READINGS ALTHOUGH STILL A BIT COOLER THAN
NORMAL IN MOST SPOTS. HIGHS MAY WARM ANOTHER DEGREE OR TWO FOR
NEXT WORK WEEK AS THE RIDGE FINALLY MAKES ITS WAY INLAND.

NO SIGNS OF A SUBSTANTIAL WARM-UP THROUGH AT LEAST THE END OF NEXT
WEEK. IN FACT...LATEST OPERATIONAL RUNS OF BOTH THE ECMWF AND GFS
BRING ANOTHER LONGWAVE TROF NEAR OUR AREA FOR THE SECOND HALF OF
NEXT WEEK.
&&

.AVIATION...AS OF 5:00 AM PDT WEDNESDAY...A PERSISTENT AREA OF
LOW PRESSURE POSITIONED OVER THE CALIFORNIA COAST WILL MAINTAIN
CLOUD COVER OVER THE TERMINALS THROUGH THE FORECAST PERIOD. A LOW
PRESSURE SYSTEM IS WORKING ITS WAY TOWARD THE COAST AND WILL
PROVIDE ENOUGH LIFT TO THE CLOUDS THAT DRIZZLE WILL BE A FACTOR
THIS EVENING.

VICINITY OF KSFO...MVFR CIGS ARE EXPECTED TO PREVAIL TODAY
STARTING OUT WITH BKN012 OVC020. CIGS WILL IMPROVE TO BKN-OVC022
BY AROUND 1900Z. WESTERLY WINDS 8 TO 10 KT WILL INCREASE TO AROUND
15 KT THIS AFTERNOON. DRIZZLE IS EXPECTED OVERNIGHT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS ARE EXPECTED TO PREVAIL
TODAY STARTING OUT THE DAY OVC018 IMPROVING TO BKN022-025 BY
AROUND 2000Z. DRIZZLE IS EXPECTED OVERNIGHT. WESTERLY WINDS WILL
REACH 10 TO 12 KT THIS AFTERNOON WITH GUSTS TO 18 KT POSSIBLE.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 3:00 AM PDT WEDNESDAY...GENERALLY LIGHT WINDS AND SEAS
ARE EXPECTED THROUGH FRIDAY AS AN AREA OF LOW PRESSURE RESIDES
OVER THE CALIFORNIA COAST. A STORM SYSTEM WILL SLIDE SOUTH ALONG
THE COAST THURSDAY INCREASING THE CHANCE OF SHOWERS INTO FRIDAY.
THE SURFACE PRESSURE GRADIENT WILL STRENGTHEN FRIDAY EVENING AS
THE STORM SYSTEM MOVES OUT OF THE AREA. THE STRENGTHENING SURFACE
PRESSURE GRADIENT WILL RESULT IN INCREASING WINDS AND
DETERIORATING SEA CONDITIONS THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM NOON

&&

$$

PUBLIC FORECAST: BELL
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA







000
FXUS66 KMTR 201159
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
459 AM PDT WED MAY 20 2015

.SYNOPSIS...COOLER THAN NORMAL WEATHER WILL CONTINUE ALONG WITH A
SLIGHT CHANCE FOR SHOWERS THROUGH THE REST OF THE WORK WEEK.
SLIGHT WARMING CAN BE EXPECTED OVER THE WEEKEND INTO NEXT WEEK AS
A RIDGE STARTS TO BUILD INTO OUR AREA.

&&

.DISCUSSION...AS OF 3:00 AM PDT WEDNESDAY...WIDESPREAD CLOUDS THIS
MORNING ACROSS OUR AREA WITH A WEAK ONSHORE FLOW ALONG WITH A
POORLY DEFINED ALBEIT DEEP MARINE LAYER. SIMILAR TO
YESTERDAY...WOULD EXPECT TO GET SOME REPORTS OF MODERATE DRIZZLE
OR RAIN LEADING TO SOME WET ROADS FOR THE MORNING COMMUTE. CLOUDS
WILL LIKELY BE SLOW TO DISSIPATE TODAY ALTHOUGH SOME BREAKS ARE
EXPECTED DOWN TO THE COAST. TEMPERATURES WILL ALSO BE SIMILAR TO
TUESDAY WITH HIGHS GENERALLY IN THE UPPER 50S TO MID 60S AT THE
COAST WHILE MID 60S TO LOWER 70S WILL BE COMMON INLAND.

OVERALL SYNOPTIC PATTERN WILL SHOW LITTLE CHANGE THROUGH FRIDAY AS
A BROAD LONGWAVE TROF WILL REMAIN OVERHEAD WHILE PIECES OF ENERGY
ROTATE THROUGH IT AND ACROSS OUR AREA. THIS WILL HELP TO KEEP
TEMPERATURES ON THE COOL SIDE PLUS PROVIDE ENOUGH INSTABILITY TO
KICK OFF A FEW SHOWERS THROUGH FRIDAY. THUNDERSTORMS CONTINUE TO BE A
POSSIBILITY OVER FAR EASTERN PORTIONS WHERE THE INSTABILITY IS THE
GREATEST AND HEATING/SUNSHINE SHOULD BE THE MOST.

A RIDGE WILL BUILD ALONG THE WEST COAST OVER THE WEEKEND AND
SLOWLY PUSH INTO OUR AREA. GUIDANCE HAS SLIGHTLY SLOWED THE
PROGRESSION OF THE RIDGE SUGGESTING THAT WARMER WEATHER COULD TAKE
AN EXTRA DAY TO ARRIVE. BY SUNDAY HIGHS WILL BE 5 TO 10 DEGREES
WARMER THAN CURRENT READINGS ALTHOUGH STILL A BIT COOLER THAN
NORMAL IN MOST SPOTS. HIGHS MAY WARM ANOTHER DEGREE OR TWO FOR
NEXT WORK WEEK AS THE RIDGE FINALLY MAKES ITS WAY INLAND.

NO SIGNS OF A SUBSTANTIAL WARM-UP THROUGH AT LEAST THE END OF NEXT
WEEK. IN FACT...LATEST OPERATIONAL RUNS OF BOTH THE ECMWF AND GFS
BRING ANOTHER LONGWAVE TROF NEAR OUR AREA FOR THE SECOND HALF OF
NEXT WEEK.
&&

.AVIATION...AS OF 5:00 AM PDT WEDNESDAY...A PERSISTENT AREA OF
LOW PRESSURE POSITIONED OVER THE CALIFORNIA COAST WILL MAINTAIN
CLOUD COVER OVER THE TERMINALS THROUGH THE FORECAST PERIOD. A LOW
PRESSURE SYSTEM IS WORKING ITS WAY TOWARD THE COAST AND WILL
PROVIDE ENOUGH LIFT TO THE CLOUDS THAT DRIZZLE WILL BE A FACTOR
THIS EVENING.

VICINITY OF KSFO...MVFR CIGS ARE EXPECTED TO PREVAIL TODAY
STARTING OUT WITH BKN012 OVC020. CIGS WILL IMPROVE TO BKN-OVC022
BY AROUND 1900Z. WESTERLY WINDS 8 TO 10 KT WILL INCREASE TO AROUND
15 KT THIS AFTERNOON. DRIZZLE IS EXPECTED OVERNIGHT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS ARE EXPECTED TO PREVAIL
TODAY STARTING OUT THE DAY OVC018 IMPROVING TO BKN022-025 BY
AROUND 2000Z. DRIZZLE IS EXPECTED OVERNIGHT. WESTERLY WINDS WILL
REACH 10 TO 12 KT THIS AFTERNOON WITH GUSTS TO 18 KT POSSIBLE.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 3:00 AM PDT WEDNESDAY...GENERALLY LIGHT WINDS AND SEAS
ARE EXPECTED THROUGH FRIDAY AS AN AREA OF LOW PRESSURE RESIDES
OVER THE CALIFORNIA COAST. A STORM SYSTEM WILL SLIDE SOUTH ALONG
THE COAST THURSDAY INCREASING THE CHANCE OF SHOWERS INTO FRIDAY.
THE SURFACE PRESSURE GRADIENT WILL STRENGTHEN FRIDAY EVENING AS
THE STORM SYSTEM MOVES OUT OF THE AREA. THE STRENGTHENING SURFACE
PRESSURE GRADIENT WILL RESULT IN INCREASING WINDS AND
DETERIORATING SEA CONDITIONS THROUGH THE WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM NOON

&&

$$

PUBLIC FORECAST: BELL
AVIATION/MARINE: LARRY

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA






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