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

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
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





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.