Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

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000
FXUS66 KMTR 292248
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
248 PM PST THU JAN 29 2015

.SYNOPSIS...DRY CONDITIONS ARE EXPECTED TO CONTINUE THROUGH NEXT
WEEK WITH CHANCES OF RAIN ONLY OVER FAR NORTHERN CALIFORNIA. TEMPERATURES
WILL REMAIN SEVERAL DEGREES ABOVE NORMAL FOR THE NEXT SEVEN DAYS
WITH A STRONG HIGH PRESSURE BUILDING IN.

&&

.DISCUSSION...AS OF 02:08 PM PST THURSDAY...
MORNING FOG HAS DISSIPATED AND GIVEN WAY TO WARM TEMPERATURES AND
SUNNY SKIES. READINGS CURRENTLY RANGE FROM THE UPPER 50S TO MID
70S...SEVERAL DEGREES ABOVE NORMAL ACROSS THE BOARD. LOW PRESSURE
DEEPENS TONIGHT ACROSS SOUTHERN CALIFORNIA AND SENDS A SLUG OF
MOISTURE INTO THE SOUTHWESTERN STATES...BUT THIS WILL NOT IMPACT
OUR AREA. WITH MAINLY CLEAR SKIES AND DEWPOINTS IN THE 40S TO LOW
50S WILL EXPECT REDEVELOPMENT OF SOME FOG TONIGHT AND HAVE
INCLUDED A MENTION IN THE SAME AREAS WHERE IT WAS A PROBLEM THIS
MORNING...PRIMARILY IN THE NORTHERN SANTA CLARA VALLEY...ALONG THE
SF BAYSHORE...AND NORTH BAY VALLEYS. THE UPPER LOW IN FAR SOUTHERN
CA WILL STRENGTHEN FRIDAY AND RIDGING WILL BEGIN TO BUILD INTO
NORTHERN CALIFORNIA BEHIND IT...ENSURING OUR AREA REMAINS IN A
QUIET AND DRY WEATHER REGIME. THE LOW WILL DROP SOUTH AS THE
RIDGING INTENSIFIES OVER NORTHERN CALIFORNIA AND HEIGHTS RISE IN
OUR AREA AS TEMPERATURES CONTINUE TO WARM ABOVE NORMAL. A SYSTEM
WILL PUSH INTO THE PACIFIC NORTHWEST BY THE TAIL END OF THE
WEEKEND BUT THE STRONG RIDGE OF HIGH PRESSURE WILL DOMINATE OUR
WEATHER AND HOLD THIS RAINFALL WELL NORTH OF THE AREA...SO HAVE
COMPLETELY REMOVED ANY PRECIP CHANCES FROM THE AREA THIS WEEKEND.
TEMPERATURES WILL BE WELL INTO THE 60S AND 70S THIS WEEKEND WITH
SUNNY SKIES.

THE RIDGE WILL HOLD ACROSS THE AREA INTO NEXT WEEK AS IT NOW
LOOKS TO BE FAIRLY CERTAIN THAT JANUARY WILL END WITH LITTLE OR NO
RAIN ACROSS OUR AREA AND FEBRUARY WILL PICK UP IN THAT SAME THEME.
THROUGH WEDNESDAY THE RIDGE HOLDS AND RAINFALL WILL REMAIN OVER
THE PACIFIC NORTHWEST BUT UNABLE TO MAKE A SOUTHWARD PUSH. THE
EXTENDED MODELS SHOW A MORE SIGNIFICANT TROUGH IN THE PACIFIC BY
THURSDAY AND FRIDAY AND AGAIN SHOW THE RIDGE BREAKING DOWN AND
RAINFALL MOVING INTO THE AREA. THIS EXTENDED MODEL RAIN ON DAYS
7-10 HAS SHOWN UP SEVERAL TIMES THIS MONTH AND NEVER
MATERIALIZED. UNTIL IT GETS CLOSER AND REMAINS IN THE MODELS
CONSISTENTLY AND PERSISTENTLY...IT IS DIFFICULT TO PUT TOO MUCH
STOCK INTO THIS IDEA OF RAIN MOVING BACK INTO THE AREA. WILL
CONTINUE TO WAIT AND SEE...WITH OPTIMISTIC HOPES...BUT THE HARSH
REALITY OF THE PERSISTENT RIDGE IN MIND.

&&

.AVIATION...AS OF 10:00 AM PST THURSDAY... GOES IMAGERY SHOWED TWO
DISTINCT LOW CLOUD DECKS CENTERED NEAR KSQL AND KSJC EARLIER THIS
MORNING. THE DECK NEAR KSFO/SQL HAS CLEARED OUT AND MOVED OVER THE
SOUTH BAY...HOWEVER FEW-SCT LOW CLOUDS MAY LINGER NEAR SAN MATEO
BRIDGE THROUGH 19Z.  THE DENSEST FOG WAS SEEN AT KSJC THIS
MORNING... WITH VISIBILITY DROPPING DOWN TO 1/8SM AND CIGS TO
VV001. WEBCAMS SHOWED IMPROVE VISIBILITY BETWEEN 17-18Z AND NOW
SHOW VASTLY IMPROVED CONDITIONS ON THE WEST SIDE OF TOWN... NR
SUNNYVALE. PATCHY FOG AND LINGERING LOW CLOUDS MAY PERSIST OVER
SANTA CLARA AND ALONG THE I880 CORRIDOR THROUGH 19Z THIS MORNING.
VFR CONDITIONS FOR THE REST OF THE DAY WITH GRADUALLY CLEARING
SKIES AND LIGHT WINDS. MODERATE CONFIDENCE IN IFR CIGS/VISBYS
RETURNING AGAIN TOMORROW MORNING.

VICINITY OF KSFO... VFR THROUGH TODAY WITH A FEW LINGERING LOW
CLOUDS AND NORTHWEST WINDS UP TO 10KT THIS AFTERNOON.

KSFO BRIDGE APPROACH...LINGERING FEW-SCT CLOUDS BTWN 300-700 FEET
THROUGH 19Z. MEDIUM CONFIDENCE.

MONTEREY BAY AREA TERMINALS...VFR TODAY WITH POSSIBLE STRATUS
INTRUSION OVERNIGHT/TOMORROW MORNING.  MEDIUM CONFIDENCE.

CONFIDENCE IS HIGH.

&&

.MARINE...AS OF 02:08 PM PST THURSDAY...NORTH WINDS INCREASE
TODAY...ESPECIALLY OVER THE OUTER WATERS... WITH THE STRONGEST
WINDS BEGINNING TONIGHT AND PERSISTING THROUGH SATURDAY MORNING.
LONG PERIOD SWELL WILL CONTINUE TO ARRIVE THROUGH THE TODAY. THIS
LONG PERIOD SWELL WILL RESULT IN BREAKING WAVES AT REEFS AND
SANDBARS ALONG THE COAST TODAY...ESPECIALLY DURING TIMES OF LOW
TIDE.

&&

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

&&

$$

PUBLIC FORECAST: JOHNSON
AVIATION: DRP
MARINE: LARRY

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