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 280017
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
517 PM PDT THU AUG 27 2015

.SYNOPSIS...LOOK FOR TEMPERATURES TO COOL INTO THE WEEKEND AS AN
UPPER LEVEL TROUGH APPROACHES THE WEST COAST. IN ADDITION...LIGHT
RAIN IS POSSIBLE ACROSS THE NORTHERN PORTION OF THE FORECAST AREA
LATE FRIDAY NIGHT AND SATURDAY MORNING. DRY AND SEASONABLY COOL
WEATHER IS EXPECTED FOR NEXT WEEK.

&&

.DISCUSSION...AS OF 2:00 AM PDT THURSDAY...AS EXPECTED A
VERY COMPRESSED MARINE LAYER PLUS OFFSHORE FLOW AT THE SURFACE
AND DRIER CONDITIONS LEAD TO WARMER TEMPS ACROSS OUR ENTIRE
REGION TODAY. AT THIS MOMENT MANY SPOTS ARE RUNNING 5 TO 10 AHEAD
OF YESTERDAY WITH MANY INLAND SPOTS NOW IN THE MID 80S TO MID 90S.
COASTAL AREAS HAVE SEEN A NICE INCREASE IN TEMPS AS WELL WITH
WIDESPREAD 70S TO LOWER 80S CURRENTLY BEING REPORTED. NORTHERLY
SURFACE FLOW IS FORECAST TO SLIGHTLY DECREASE OVERNIGHT WHICH
SHOULD HELP TO BRING CLOUDS BACK TO NEAR THE COAST OVERNIGHT
ALTHOUGH WITH THE MARINE LAYER STILL NEAR ZERO WOULD NOT EXPECT
MANY CLOUDS IF ANY FOR SPOTS AWAY FROM THE OCEAN. LOWS WILL STAY
VERY WARM FOR HIGHER ELEVATION SPOTS WITH GENERALLY 50S TO MID 60S
FOR URBAN AREAS.

A LONGWAVE TROF THAT IS APPROACHING THE WEST COAST WILL CONTINUE
TO ADVANCE TO THE EAST. MODELS REMAIN IN GOOD AGREEMENT THAT THE
TROF AXIS WILL BE NEAR THE COAST LATER SATURDAY INTO SUNDAY.
RAINFALL ASSOCIATED WITH A COLD FRONT AHEAD OF THE TROF WILL
SPREAD FROM THE PACNW DOWN TO NORCAL THROUGH FRIDAY. BASED OFF OF
THE VARIOUS MODELS LIGHT RAIN MAY MOVE THROUGH THE NORTHERN
PORTION OF THE CWA LATE FRIDAY INTO SATURDAY. ANY RAINFALL WILL
LIKELY BE VERY LIGHT WITH JUST A TRACE TO A FEW HUNDREDTHS AROUND
SAN FRANCISCO. UP TO A TENTH OF AN INCH LOCALLY COULD FALL OVER
THE NORTH BAY MOUNTAINS. DRY WEATHER RETURNS LATE SATURDAY. BIGGER
IMPACT OF THE SYSTEM WILL BE COOLER WEATHER. SOME INLAND SPOTS
WILL BE 15 TO 20 DEGREES COOLER THAN WHAT WE ARE SEEING TODAY.

FOR NEXT WEEK...SIMILAR THINKING TO THE PAST FEW DAYS AS THE
OVERALL CONUS PATTERN HAS A LONGWAVE TROF OVER THE WEST WITH A
RIDGE TO THE EAST. TEMPS WILL AVERAGE COOLER THAN NORMAL. RAINFALL
IS NOT EXPECTED AS THE MAIN STORM TRACK REMAINS WELL TO OUR NORTH.
&&

.AVIATION...AS OF 4:50 PM PDT THURSDAY....INCREASING HIGH CLOUDS
AND VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. LIGHT TO
MODERATE ONSHORE FLOW WITH OCCASIONAL STRONGER GUSTS POSSIBLE THIS
AFTERNOON AND EVENING.

VICINITY OF KSFO...VFR. LIGHT TO MODERATE ONSHORE WINDS WITH
OCCASIONAL STRONGER GUSTS THROUGH THIS AFTERNOON AND EVENING.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR. LIGHT WINDS.

&&

.MARINE...AS OF 2:46 PM PDT THURSDAY...NORTHWEST WINDS WILL
CONTINUE OVER THE COASTAL WATERS TODAY...WITH THE STRONGEST WINDS
FROM PIGEON POINT SOUTHWARD THROUGH THE BIG SUR COASTLINE. WINDS
WILL GRADUALLY WEAKEN OVERNIGHT AND INTO TOMORROW. LONG PERIOD
SWELL HAS BEGUN TO MOVE INTO THE AREA... AND MORE ENERGETIC WEST-
NORTHWESTERLY SWELL WILL IMPACT THE REGION THIS WEEKEND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY UNTIL 9 PM
             SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 9 PM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 3 AM

&&

$$

PUBLIC FORECAST: BELL
AVIATION: CW
MARINE: DRP


VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO

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



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