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

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737
FXUS66 KMTR 140616 CCA
AFDMTR

AREA FORECAST DISCUSSION...CORRECTED AVIATION DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1012 PM PST SAT FEB 13 2016

...WARM WEATHER TO RETURN SUNDAY THROUGH TUESDAY...

.SYNOPSIS...HIGH PRESSURE WILL STRENGTHEN OVER CALIFORNIA DURING
THE NEXT FEW DAYS. RECORD HIGH TEMPERATURES ARE POSSIBLE EARLY IN
THE WEEK. ON WEDNESDAY TEMPERATURES WILL COOL AS A TROUGH
APPROACHES WITH RAIN BECOMING LIKELY WEDNESDAY NIGHT INTO
THURSDAY. SHOWERS WILL END BY THURSDAY AFTERNOON...WITH A RETURN
TO DRY WEATHER FRIDAY THROUGH NEXT WEEKEND.

&&

.DISCUSSION...AS OF 9:00 PM PST SATURDAY...PATCHY LOW CLOUDS AND
FOG NEAR MONTEREY BAY FINALLY CLEARED BY LATE AFTERNOON. SKIES
REMAIN CLEAR ACROSS THE ENTIRE FORECAST AREA THIS EVENING EXCEPT
FOR SOME THIN HIGH CLOUDS OVERSPREADING THE SF BAY AREA. DRIER AIR
HAS BEGUN TO MIX INTO THE BOUNDARY LAYER...PARTICULARLY IN THE
NORTH BAY WHERE NORTHERLY WINDS HAVE PICKED UP AND SURFACE
DEWPOINTS ARE UP TO 13 DEGREES BELOW WHAT THEY WERE 24 HOURS AGO.
FURTHER SOUTH...ENOUGH MOISTURE REMAINS IN THE LOW LEVELS FOR
PATCHY FOG AND LOW CLOUDS TO DEVELOP OVERNIGHT...PRIMARILY NEAR
MONTEREY BAY. WHERE FOG DOES DEVELOP LATER TONIGHT...IT WILL
PROBABLY BE DENSE.

AN UPPER LEVEL RIDGE IS FORECAST TO BUILD JUST OFFSHORE TONIGHT
AND SUNDAY...WITH H5 HEIGHTS FORECAST TO REACH 585 DM BY LATE
SUNDAY. SUBSIDENCE UNDER THIS RIDGE WILL PUSH 850 MB TEMPS UP TO
14 DEG C BY SUNDAY AFTERNOON AND AS HIGH AS 16 C BY LATE MONDAY.
AT THE SAME TIME...SURFACE HIGH PRESSURE BUILDING TO OUR NORTH AND
EAST WILL GENERATE MODERATE OFFSHORE FLOW...BRINGING DRIER AIR
INTO OUR REGION. THESE DEVELOPMENTS WILL ALLOW TEMPERATURES TO
CLIMB OVER THE NEXT THREE DAYS...WITH HIGHS FORECAST TO BE
ANYWHERE FROM 10 TO 20 DEGREES WARMER THAN NORMAL. AT LEAST A FEW
DAILY RECORD HIGH TEMPS ARE LIKELY. TEMPERATURES WILL LIKELY PEAK
IN THE NORTH BAY VALLEYS ON SUNDAY AND MONDAY WHEN NORTHERLY FLOW
WILL PRODUCE THE BEST DOWNSLOPE CONDITIONS. WARMEST TEMPS NEAR THE
COAST WILL PROBABLY BE ON MONDAY WHEN OFFSHORE FLOW WILL BE MOST
ROBUST. ELSEWHERE...WARMEST TEMPS WILL BE ON MONDAY AND TUESDAY.

NORTH TO NORTHEAST WINDS WILL INCREASE IN THE HILLS TONIGHT AND
BECOME LOCALLY STRONG AND GUSTY OVER THE HIGHER RIDGES AND PEAKS
BY LATE TONIGHT. BREEZY CONDITIONS IN THE HILLS ARE THEN EXPECTED
TO CONTINUE ON THROUGH MONDAY. LOCAL GUSTS UP TO 40 MPH ARE
POSSIBLE IN THE HILLS FROM LATE TONIGHT THROUGH MONDAY...BUT
WIDESPREAD WIND ADVISORY CONDITIONS ARE NOT EXPECTED. GUSTY
NORTHERLY WINDS WILL MIX LOCALLY DOWN TO NEAR SEA LEVEL AT
TIMES...PARTICULARLY NEAR COASTAL CANYONS AT NIGHT AND IN THE
VALLEYS DURING THE DAYTIME HOURS. BUT FOR THE MOST
PART...STRONGEST WINDS ARE EXPECTED TO BE CONFINED TO THE HILLS.

THE MODELS CONTINUE TO SHOW A PACIFIC STORM SYSTEM OF MODERATE
INTENSITY MOVING THROUGH NORTHERN AND CENTRAL CALIFORNIA FROM LATE
WEDNESDAY THROUGH THURSDAY MORNING. THERE APPEARS A REASONABLY
GOOD CHANCE THAT OUR REGION WILL SEE WIDESPREAD RAINFALL FROM THIS
SYSTEM. HOWEVER...THE MODELS CURRENTLY INDICATE THAT THE BEST
MOISTURE AND DYNAMICS WITH THIS SYSTEM WILL BE OUT OF PHASE...WITH
THE GREATEST MOISTURE FOCUSED WELL SOUTH OF OUR AREA AND AWAY FROM
SIGNIFICANT DYNAMICS. THUS...MOST MODEL OUTPUT INDICATE OUR AREA
WILL SEE ONLY LIGHT TO MODERATE AMOUNTS OF RAINFALL...GENERALLY
FROM 0.25" TO 0.75". THE MIDWEEK SYSTEM MAY BE OUR LAST SHOT AT
PRECIPITATION OF ANY SIGNIFICANCE FOR THE NEXT TEN DAYS AS THE
LONGER RANGE MODELS FORECAST THE RIDGE TO REDEVELOP BY NEXT
WEEKEND AND INTO THE FOLLOWING WEEK. AND...RAIN CHANCES LOOK BLEAK
EVEN BEYOND TEN DAYS GIVEN THE 12Z GFS ENSEMBLE MEAN HOLDS THE
RIDGE POSITION NEAR THE WEST COAST THROUGH THE END OF FEBRUARY.

&&

.AVIATION...AS OF 10:12 PM PST SATURDAY...CIRRUS CLOUDS WELL SOUTH
OF A STRONG JET STREAM ENTERING THE PACIFIC NW CONTINUE TO SPILL
INTO THE FORECAST AREA THIS EVENING. STRONG NORTHERLY GRADIENTS
WILL CONTINUE INTO SUNDAY...UKI-STS GRADIENT IS PRESENTLY 2.2 MB
AND SFO-SBA 7.5 MB.

VICINITY OF KSFO....MODERATE TO HIGH CONFIDENCE VFR.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MODERATE TO HIGH CONFIDENCE VFR. A
FEW FOG PATCHES ARE POSSIBLE NEARBY EITHER LATE TONIGHT AND/OR
EARLY SUNDAY MORNING.

&&

.CLIMATE...HERE IS A LIST OF RECORD HIGH TEMPERATURES FROM SUNDAY
FEBRUARY 14 THROUGH TUESDAY FEBRUARY 16. THE RECORD HIGH IS LISTED
FOR EACH DAY ALONG WITH THE YEAR THE RECORD WAS SET (IF THE RECORD
WAS SET ON MORE THAN ONE YEAR...THE MOST RECENT YEAR IS LISTED).

                          SUNDAY         MONDAY         TUESDAY
LOCATION                  FEB 14         FEB 15         FEB 16

SAN FRANCISCO BAY AREA...
  KENTFIELD               84/1930        79/1930        77/1930
  SAN RAFAEL              78/1977        78/1977        77/1977
  NAPA                    81/1930        81/1943        81/1930
  SAN FRANCISCO DOWNTOWN  78/1930        76/1930        75/1930
  SAN FRANCISCO AIRPORT   74/1977        75/2015        69/2007
  OAKLAND MUSEUM          80/1977        80/2015        75/2015
  OAKLAND AIRPORT         72/2013        73/1977        73/1977
  RICHMOND                77/1977        75/1977        75/2015
  LIVERMORE               79/1977        80/1933        78/1977
  MOFFETT FIELD           82/1977        79/1977        73/1977
  SAN JOSE                80/1930        80/1930        78/1930
  GILROY                  80/1996        81/1991        81/1977

MONTEREY BAY AREA...
  MONTEREY                81/1943        79/1977        73/2013
  SANTA CRUZ              82/2015        82/1916        85/1930
  SALINAS                 83/2015        81/2013        80/1977
  SALINAS AIRPORT         84/2015        81/2015        77/2013
  KING CITY               85/1977        86/1977        90/1977

&&

.MARINE...AS OF 9:23 PM PST SATURDAY...STRONG HIGH PRESSURE LOCATED
OVER THE EASTERN PACIFIC WILL BUILD OVER NORTHERN CALIFORNIA
THROUGH THE HOLIDAY WEEKEND. AS A RESULT GUSTY NORTHWESTERLY TO
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS WITH LIGHTER
WINDS OVER THE BAYS. A CHANCE OF RAIN WITH A FRONTAL SYSTEM WILL
MOVE EAST OVER THE AREA LATE WEDNESDAY NIGHT INTO THURSDAY MORNING
OF NEXT WEEK.

&&

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

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: CANEPA
CLIMATE: DYKEMA

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