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

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 252128
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
228 PM PDT SAT APR 25 2015

.SYNOPSIS...HIGH PRESSURE WILL PRODUCE WARM AND DRY CONDITIONS ON
SUNDAY AND MONDAY. A COOLING TREND WILL DEVELOP BY THE MIDDLE OF
NEXT WEEK AS A DRY UPPER TROUGH DEVELOPS OVER NORTHERN CALIFORNIA.

&&

.DISCUSSION...AS OF 03:00 PM PDT SATURDAY... THE COLD FRONT AND
ASSOCIATED PRECIPITATION BAND WHICH SWEPT THROUGH THE AREA
OVERNIGHT HAS NOW EXITED THE REGION TO THE SOUTH AND EAST. RAINFALL
TOTALS WERE IMPRESSIVE CONSIDERING THE SPEED AT WHICH THE FRONT
PUSHED THROUGH. THE PRECIPITABLE WATER PLUME ASSOCIATED WITH THIS
FRONTAL PASSAGE WAS AROUND 160% OF NORMAL. PRECIPITATION AMOUNTS
WERE HIGHEST OVER THE BIG SUR COASTLINE WHERE SEVERAL HIGH
ELEVATION LOCATIONS REPORTED OVER TWO INCHES OF RAINFALL AND PICO
BLANCO REPORTED 2.52 INCHES OF RAIN. RAINFALL TOTALS BETWEEN A
QUARTER AND THREE QUARTERS OF AN INCH WERE OBSERVED THROUGHOUT
MANY LOW LYING URBAN AREAS. SEE THE LATEST PNSMTR FOR ADDITIONAL
CITY BY CITY RAINFALL TOTAL OBSERVATIONS.

VISIBLE SATELLITE IMAGERY SHOWS RAPID CLEARING IN THE POST FRONTAL
ENVIRONMENT OVER THE FORECAST AREA... LEADING TO MOSTLY TO PARTLY
SUNNY CONDITIONS. TEMPERATURES ARE RUNNING A FEW DEGREES COOLER
THIS AFTERNOON VERSUS YESTERDAY AS A RESULT OF THE COOLER AIR MASS
IN THE WAKE OF THE FRONT. SFO-WMC HAS DWINDLED FROM 10MB ONSHORE
24 HOURS AGO TO 5 MB ONSHORE AS OF AN HOUR AGO. WINDS ARE EXPECTED
TO INCREASE ALONG THE COAST AS THE UPPER LOW RESPONSIBLE FOR THIS
MORNINGS RAIN ROTATES INTO THE GREAT BASIN... WHICH WILL CONTRAST
SHARPLY WITH THE HIGH PRESSURE SET TO PUSH INLAND SUNDAY. THIS
HIGH PRESSURE WILL RESULT IN A GENERAL WARMING AND DRYING TREND
WHICH WILL PEAK ON MONDAY. HIGH TEMPERATURES ARE EXPECTED TO BE IN
THE 60S ALONGSHORE TO 80S INLAND WHEN THE RIDGE APEX ALIGNS WITH
THE AREA MONDAY. THE HIGH PRESSURE RIDGE PROGRESSES DOWNSTREAM BY
MIDWEEK AND GIVE WAY TO A WEAK TROUGH TO THE NORTH. THIS WILL
PROMOTE MARGINAL COOLING BUT CONTINUE THE DRY TREND THROUGH THE
REMAINDER OF THE WORKWEEK. COASTAL STRATUS WILL ATTEMPT TO RETURN MONDAY
NIGHT/TUESDAY MORNING.


&&

.AVIATION...AS OF 11:25 AM PDT SATURDAY...FOR 18Z TAFS. REGION IS
IN POST FRONTAL REGIME WITH GUSTY NW ONSHORE WINDS ALLOWING SOME
CLOUDS TO PILE UP ALONG THE COASTAL HILLS. IN GENERAL EXPECT
CLOUDS TO BECOME SCATTERED THROUGH THE AFTERNOON EXCEPT NEAR
MONTEREY BAY WHERE BKN CIGS MAY PREVAIL. OTHER ISSUE WILL BE
STRONG WESTERLY WINDS WITH GUSTS TO 30 KT ALREADY AT KSFO. WINDS
WILL GRADUALLY EASE THIS EVENING AND ENOUGH BOUNDARY LAYER
MOISTURE FOR LOW CLOUDS TO REFORM. EXPECT MORE RAPID CLEARING
SUNDAY MORNING.

VICINITY OF KSFO...LATEST OBS AND WEB-CAMS NOW SHOWING SCT CLOUDS.
EXPECT THIS TO PREVAIL THROUGH THE DAY. WEST WINDS ALREADY GUSTING
TO 30 KT AND EXPECT THIS TO CONTINUE AT LEAST THROUGH SUNSET.

CONFIDENCE IS MODERATE TO HIGH.

SFO BRIDGE APPROACH...SIMILAR TO KSFO. BUT WINDS NOT QUITE AS
STRONG.

MONTEREY BAY AREA TERMINALS..NW ONSHORE WINDS ALLOWING LOW CLOUDS
TO PILE UP ON MONTEREY PENINSULA THIS AFTERNOON. CURRENT OVC006 AT
KMRY SHOULD LIFT ABOVE 1000 FEET BUT CIGS MAY PREVAIL AT KMRY AND
KSNS THROUGH THE DAY. HAVE PUT A TEMPO SCT GROUP FOR THIS AFTERNOON.
EXPECT LOW CIGS TO REFORM OVERNIGHT.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 01:51 PM PDT SATURDAY...GUSTY NW WINDS WILL
CONTINUE TODAY THROUGH SUNDAY BEHIND LAST NIGHTS COLD FRONTAL
PASSAGE. MODERATE NORTHERLY WINDS ARE FORECAST TO PREVAIL THROUGH
MIDWEEK AS HIGH PRESSURE BUILDS OVER THE EASTERN PACIFIC AND THE
SURFACE PRESSURE GRADIENT STRENGTHENS. THE STRENGTHENING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PIGEON PT TO PT PINOS 0-10 NM
             SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM
             SCA...PIGEON PT TO PT PINOS 10-60 NM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
             SCA...PT ARENA TO PT REYES 0-10 NM
             SCA...PT REYES TO PIGEON PT 0-10 NM
             SCA...MONTEREY BAY UNTIL 9 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM
             SCA...SF BAY SOUTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: DRP
AVIATION/MARINE: RWW

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.