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 022352
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
452 PM PDT TUE SEP 2 2014

.SYNOPSIS...DRY CONDITIONS WILL PERSIST THROUGH THE PERIOD ALONG
WITH TEMPERATURES NEAR OR SLIGHTLY BELOW NORMAL. OVERNIGHT CLOUDS
CAN BE EXPECTED IN MOST LOCATIONS.

&&

.DISCUSSION...AS OF 3:00 PM PDT TUESDAY...ONSHORE FLOW AT THE
SURFACE ALONG WITH A 2000 FOOT MARINE LAYER HAS BENN ENOUGH TODAY TO
KEEP CLOUDS GOING ALONG MOST OF THE COAST THIS AFTERNOON. IN
ADDITION, THE STRONGER WINDS OFF THE COOLER WATERS HAVE HELPED TO
COOL ALMOST ALL LOCATIONS. OVER THE NORTH BAY SOME SPOTS AREA
RUNNING MORE THAN 20 DEGREES COOLER THAN THIS TIME YESTERDAY.
ANOTHER ROUND OF WIDESPREAD CLOUDS IS ANTICIPATED TONIGHT ALONG
THE COAST PLUS ADJACENT VALLEYS. DRIZZLE IS ALSO POSSIBLE ALONG
THE COAST TONIGHT.

SYNOPTICALLY FOR THE WEEK A LONGWAVE TROF WILL ADVANCE TO NEAR OUR
CWA AND REMAIN FAIRLY STATIONARY INTO THE WEEKEND. WITH A 2000
PLUS MARINE LAYER EXPECTED PLUS ONSHORE FLOW AT THE SURFACE, TEMPS
SHOULD END UP BEING A FEW DEGREES COOLER THAN NORMAL -- ESPECIALLY
FOR INLAND SPOTS. EXPECT 60S AND 70S AT THE COAST WITH MID 70S TO
UPPER 80 FOR MOST INLAND LOCATIONS.

FOR NEXT WEEK THE ECMWF BUILD A RIDGE OF HIGH PRESSURE BACK INTO
OUR AREA WITH GUIDANCE SUGGESTING ANOTHER ROUND OF ABOVE NORMAL
TEMPERATURES.
&&

.AVIATION...AS OF 4:50 PM PDT TUESDAY...THERE`S PLENTY OF COASTAL
STRATUS SOUTH OF CAPE MENDOCINO ALL THE WAY TO POINT CONCEPTION AS
SEEN ON VISIBLE IMAGERY. THE MARINE LAYER IS APPROXIMATELY 2000
FEET DEEP PER THE BODEGA BAY AND FORT ORD PROFILERS. PATCHY LIGHT
DRIZZLE IS INDICATED IN KMRY...KSNS TAFS AS WELL AS IN SOME OF THE
BAY AREA TAFS FOR TONIGHT. STS-UKI PRESS GRADIENT IS QUITE ROBUST
BETWEEN 2 AND 3 MB THIS AFTERNOON...SUGGESTING POTENTIAL FOR A
DECENT STRATUS PUSH INTO THE NORTH BAY COUNTIES THIS EVENING. A
DEEPER LAYER OF STRATUS WILL LIKELY HOLD LONGER IN THE NORTH BAY
ON WEDNESDAY.

VICINITY OF KSFO...LIGHTER NORTHERLY WINDS COMBINED WITH SLIGHTLY
MORE ROBUST ONSHORE GRADIENTS AND A MODERATELY DEEP MARINE LAYER
SUGGESTS A HIGHER POTENTIAL FOR EARLY RETURN AT KSFO. AGREE WITH
THE CWSU FORECASTER TIMING STRATUS RETURN THIS EVE BY 05Z. OFFSETTING
THE EARLY RETURN POTENTIAL IS A SOMEWHAT STRONGER SOUTHERLY COMPONENT
EVIDENT IN THE SURFACE WIND IN THE APPROACH ZONE WHICH MAY HELP
DELAY STRATUS JUST A LITTLE THIS EVENING...BUT BEGINNING FORECAST
TEMPO BKN CIG 05Z-07Z IS A GOOD PLACE TO START.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...THERE`S A SOLID LAYER OF STRATUS
CLOUDS OVER THE MONTEREY BAY PER SATELLITE PICTURES. MVFR CEILINGS
WILL LIKELY LOWER TO IFR BY 04Z. LIGHT DRIZZLE IS POSSIBLE IN THE
OVERNIGHT HOURS AS WELL. LOW CONFIDENCE ON CEILINGS MIXING OUT WED
MORNING HOWEVER LOW LEVEL CYCLONIC CIRCULATION OVER THE INNER COASTAL
WATERS JUST NORTH OF THE MONTEREY BAY COULD BRING IN A STRONGER
SOUTHERLY COMPONENT TO THE WIND WHICH USUALLY HELPS SHIFT THE
MAJORITY OF STRATUS NORTH TO SANTA CRUZ SIDE OF THE BAY AND ALLOWS
FOR EASIER MIXING/CLEARING OVER THE SOUTHERN HALF OF THE MONTEREY
BAY.

&&

.MARINE...AS OF 5:00 AM PDT TUESDAY...HIGH PRESSURE CONTINUES OFF
THE PACIFIC NORTHWEST COAST. A THERMAL TROUGH WILL SHIFT TO THE
COAST RESULTING IN DECREASING WINDS OVER THE AREA EXCEPT FOR THE
OUTER WATERS NORTH OF POINT REYES.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 9 PM

&&

$$

PUBLIC FORECAST: BELL
AVIATION: CANEPA
MARINE: W PI

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.