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 141201
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
501 AM PDT MON JUL 14 2014

.SYNOPSIS...THE WARMING TREND IS FORECAST TO PEAK THIS AFTERNOON
ALONG WITH AN INCREASE IN MID/HIGH LEVEL CLOUDS SPREADING
NORTHWARD OVER THE REGION. AS THE HIGH PRESSURE RIDGE TO OUR EAST
WEAKENS BY MIDWEEK...NEAR SEASONAL CONDITIONS WILL RETURN FOR THE
REMAINDER OF THE WORK WEEK.

&&

.DISCUSSION...AS OF 04:30 AM PDT MONDAY...STRONG MID/UPPER LEVEL
RIDGE CONTINUES TO BE CENTERED OVER NEVADA THIS MORNING WITH VERY
WARM 850MB TEMPERATURES ACROSS THE REGION. WITH THIS WARM AIR MASS
ALOFT...TEMPERATURES ARE IN THE 80S THIS MORNING IN THE HIGHER
ELEVATIONS. OTHERWISE...TEMPERATURES ARE GENERALLY IN THE 50S FOR
MOST LOCATIONS AWAY FROM THE HILLS/MOUNTAINS. IN ADDITION...THE
MARINE LAYER IS BELOW 1000 FT AT THIS HOUR ALONG WITH NORTHERLY
WINDS IN THE BOUNDARY LAYER. THIS HAS KEPT STRATUS FROM FORMING
ACROSS MUCH OF THE REGION...ONLY PATCHY LOW CLOUDS OVER HALF MOON
BAY AND PORTIONS OF THE MONTEREY PENINSULA.

WITH THE VERY WARM TEMPERATURES OFF THE SURFACE AND MOSTLY CLEAR
SKIES...TEMPERATURES WILL RAPIDLY WARM BY EARLY AFTERNOON.
EXPECTING MOST LOCATIONS TO BE WARMER THAN YESTERDAY...ESPECIALLY
INLAND. MEANWHILE...AS THE RIDGE TO OUR EAST SHIFTS SLIGHTLY
NORTHWARD...MONSOONAL MOISTURE WILL CONTINUE TO ADVECT
NORTHWESTWARD ACROSS SOUTHERN CALIFORNIA AND ACROSS THE CENTRAL
COAST THIS AFTERNOON. THIS WILL RESULT IN AN INCREASE IN MID/HIGH
LEVEL CLOUDS AND COULD HELP INHIBIT MAXIMUM WARMING. CONTINUE TO
BELIEVE THE NEEDED LIFT AND INSTABILITY WILL BE LACKING THIS
AFTERNOON/EVENING TO PRODUCE ELEVATED CONVECTION ACROSS OUR
REGION. HAVING SAID THAT...IT IS NOT COMPLETELY OUT OF THE
QUESTION FOR ISOLATED ACTIVITY TO DEVELOP OVER SOUTHERN MONTEREY
AND SAN BENITO COUNTIES GIVEN THE INCREASED MID-LEVEL MOISTURE.
SOMETHING WE WILL NEED TO KEEP AN EYE ON FOR THE REMAINDER OF THE
DAY.

OTHERWISE...THE MID/UPPER LEVEL RIDGE IS FORECAST TO WEAKEN OVER
THE REGION TUESDAY THROUGH THE END OF THE WEEK. THIS SHOULD ALLOW
FOR THE MARINE INFLUENCE TO RETURN BY MIDWEEK. TEMPERATURES WILL
COOL BACK TO NEAR SEASONAL AVERAGES AND THE MARINE LAYER WILL
LIKELY ALLOW FOR THE DEVELOPMENT OF OVERNIGHT/EARLY MORNING
STRATUS TO SPREAD INLAND. IN ADDITION...A DRIER AIR MASS ALOFT
WILL RETURN AND SCOUR OUT THE MID/HIGH LEVEL CLOUDS BY LATE IN THE
WEEK.

&&

.AVIATION...AS OF 4:50 AM PDT MONDAY...LOW CLOUD PATCHES ON THE
IMMEDIATE COAST WILL QUICKLY MIX OUT THIS MORNING. AREA SURFACE
WINDS ARE LIGHT W-NW BUT THERE IS A DEVELOPING SUB-TROPICAL
MOISTURE PLUME ON S-SE MID-UPPER LEVEL WINDS BAY AREA TO SOCAL.
MID LEVEL SATURATED AIR CAN BECOME QUICKLY UNSTABLE IF SUFFICIENT
LIFT IS PRESENT AND MODEL CROSS SECTIONS DO SHOW SOME MID LEVEL
FORCING FROM SOUTH TO NORTH THIS AFTERNOON AND EVENING. HARD TO
SAY WHAT WILL BECOME OF THIS LAYER AS THERE WILL ALSO BE SOME
CONVECTIVE INHIBITION OFFSETTING THE INSTABILITY. NOT CONFIDENT
ENOUGH ABOUT FORECAST TO PLACE VCSH OR VCTS IN 12Z TAFS BUT PILOTS
AND DISPATCHERS SHOULD BE AWARE OF POSSIBLE CHANGEABLE WEATHER
TODAY INCLUDING OUR AREA OF RESPONSIBILITY.

VICINITY OF KSFO...VFR. WEST WINDS 5 TO 15 KNOTS.

KSFO BRIDGE APPROACH...VFR.

MONTEREY BAY AREA TERMINALS...PATCHY IFR EARLY. KMRY REPORTS 400
FEET BUT IT`S THIN...WE CAN SEE THE MOON THROUGH THE LOW CLOUD
COVER. LOW CLOUDS SHOULD MIX OUT FAIRLY QUICKLY THIS MORNING.
OTHERWISE VFR TODAY.

&&

.MARINE...AS OF 04:30 AM PDT MONDAY...HIGH PRESSURE OFF THE WEST
COAST AND THERMAL LOW PRESSURE OVER THE CALIFORNIA INTERIOR WILL
KEEP MODERATE WINDS ALONG THE COAST TODAY. WINDS WILL DECREASE BY
TONIGHT AS THE THERMAL TROUGH SHIFTS TO THE COAST.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 6 PM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 9 AM
             SCA...PT REYES TO PIGEON PT 10-60 NM
             SCA...PIGEON PT TO PT PINOS 10-60 NM UNTIL 11 AM

&&

$$

PUBLIC FORECAST: RGASS
AVIATION/MARINE: CANEPA

VISIT US AT WEATHER.GOV/SANFRANCISCO

FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
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.