832
FXUS66 KMTR 150047
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
547 PM PDT MON APR 14 2025
..NEW AVIATION, MARINE
SYNOPSIS
ISSUED AT 311 PM PDT MON APR 14 2025
A PATTERN CHANGE BEGINS ON TUESDAY BRINGING COLDER TEMPERATURES
TUESDAY INTO THURSDAY. WARM TEMPERATURES RETURN BY THE WEEKEND.
SLIGHT CHANCE FOR THUNDERSTORMS WEDNESDAY.
SHORT TERM
(THIS EVENING THROUGH TUESDAY)
ISSUED AT 311 PM PDT MON APR 14 2025
AS THE RIDGE STARTS TO EXIT TO THE EAST AND MAKES WAY FOR THE UPPER
LEVEL LOW TO TAKE INFLUENCE OVER OUR AREA, TEMPERATURES WILL BEGIN
TO LOWER. OVERNIGHT TEMPERATURES WILL SEE ABOUT 2-6 DEGREES
DIFFERENCE FROM LAST NIGHT TO TONIGHT WITH TEMPERATURES IN THE MID
TO HIGH 40S. THE MAX TEMPERATURES ON TUESDAY WILL SHOW A MORE
NOTICEABLE DIFFERENCE WITH A 6-12 DEGREES DIFFERENCE INLAND.
ALONG THE COAST, TEMPERATURES WILL BE IN THE UPPER 50S TO 60S FOR
THE MOST PART, BUT INLAND AREAS WILL DROP TO WIDESPREAD 60S, WITH
HIGHER TERRAIN SEEING UP TO LOW 70S. THE MARINE LAYER WILL REBUILD
TONIGHT BRINGING ANOTHER ROUND OF FOG AND/OR DRIZZLE ALONG THE
COAST EARLY TUESDAY MORNING. THERE IS A CHANCE THAT THE FOG WILL
PUSH FURTHER INLAND NEAR NORTH BAY AND MONTEREY BAY AS WELL.
MODELS DO SHOW A SIGNAL FOR SOME INSTABILITY OVERNIGHT INTO EARLY
TUESDAY MORNING. WHILE THE PROBABILITY OF THUNDERSTORMS (AROUND 15-
20%) PEAKS LATE WEDNESDAY INTO THURSDAY, WE WILL NEED TO MONITOR
TRENDS FOR CONVECTION LATE THIS EVENING AND INTO THE PRE-DAWN HOURS
ON TUESDAY, ALTHOUGH PROBABILITY IS VERY LOW. STEEP MID-LEVEL LAPSE
RATES ON THE ORDER OF 8 C/KM ARE ANTICIPATED TO OVERSPREAD THE
REGION FROM THE SOUTH AND SOUTHEAST AND PRECIPITABLE WATER VALUES
WILL INCH ABOVE 0.75", BUT THE BULK OF THE UPPER LEVEL MOISTURE
REMAINS DISPLACED FROM THE LIFT. THEREFORE, WE WILL CONTINUE TO
MONITOR THE TRENDS FOR TONIGHT INTO TUESDAY MORNING.
LONG TERM
(TUESDAY NIGHT THROUGH NEXT SUNDAY)
ISSUED AT 311 PM PDT MON APR 14 2025
THE UPPER LEVEL LOW THAT SITS OFF THE COAST OF SOUTHERN CA CONTINUES
TO STRENGTHEN AND WILL GRADUALLY MOVE INLAND. THIS WILL ALLOW FOR A
RETURN OF PREDOMINATELY ONSHORE FLOW AND COLDER TEMPERATURES, ALONG
WITH AN INCREASE IN CLOUD COVER AND MOISTURE FROM THE SOUTH. MODELS
CONTINUE TO SHOW AGREEMENT THAT THE LOW PRESSURE SYSTEM WILL BRING
SOME UNSTABLE ATMOSPHERE OVER OUR AREA WEDNESDAY AFTERNOON AND
CONDITIONS LOOK A BIT MORE FAVORABLE FOR HIGH-BASED CONVECTION.
ALSO, SPC HAS HIGHLIGHTED OUR AREA UNDER A GENERAL RISK FOR
THUNDERSTORM. THEREFORE, WE HAVE ADDED A CHANCE (15-20%) FOR
ISOLATED THUNDERSTORMS FOR WEDNESDAY, ESPECIALLY IN THE AFTERNOON.
IN ADDITION, WITH THE DEEPENING OF THE MARINE LAYER, THERE IS A
CHANCE FOR MORNING COASTAL FOG AND DRIZZLE.
ON FRIDAY, CLUSTER ANALYSIS SHOWS A REASONABLE AGREEMENT FOR ANOTHER
RIDGE PUSHING IN FROM THE EAST PACIFIC, BRINGING BACK SOME WARMER
TEMPERATURES AND DRIER CONDITIONS FOR THE WEEKEND. SO FAR, INLAND
AREAS ARE EXPECTED TO REACH IN THE MID TO HIGH 70S, WHICH REFLECTS
CLOSE TO NORMAL AVERAGE TEMPERATURES.
AVIATION
(00Z TAFS)
ISSUED AT 547 PM PDT MON APR 14 2025
MODERATE WINDS REDUCE INTO THE NIGHT BECOMING LIGHT. LOW CLOUDS ARE
ALREADY AFFECTING THE MONTEREY BAY TERMINALS AND HAF. THESE CLOUDS
WILL SLOWLY MOVE FARTHER INLAND OVERNIGHT AFFECTING MOST OF THE TAF
SITES. ADDITIONALLY, TERMINALS ALONG THE COAST AS WELL AS STS LOOK TO
HAVE CIGS FALL TO LIFR LEVELS WITH FOG AFFECTING THOSE SITES THROUGH
A GOOD PORTION OF TUESDAY MORNING. CLOUD COVER BEGINS TO ERODE IN
THE MID TO LATE MORNING, BUT WIDESPREAD CLEARING ISN'T EXPECTED
UNTIL TUESDAY AFTERNOON AS MODERATE WINDS BUILD AND HELP MIX OUT THE
CLOUD COVER.
VICINITY OF SFO...VFR LASTS INTO EARLY TUESDAY. EXPECT WINDS TO
REDUCE INTO THE EARLY NIGHT BECOMING LIGHT AND SLIGHTLY MORE
SOUTHERLY THROUGH THE EARLY AFTERNOON. CIGS FILL OVER THE OAK AND
THE EASTERN PORTIONS OF THE SF BAY, BUT STRUGGLE TO CONSISTENTLY
FILL OVER SFO IN THE MID MORNING BEFORE EXITING IN THE LATE
MORNING. WEST WINDS WILL INCREASE AGAIN INTO TUESDAY AFTERNOON, BUT
ONLY TO MODERATE SPEEDS BEFORE BECOMING LIGHT AGAIN INTO THAT NIGHT.
SFO BRIDGE APPROACH...SIMILAR TO SFO
MONTEREY BAY TERMINALS...MVFR CIGS ARE PUSHING INLAND AROUND THE
MONTEREY BAY COAST, AND HAVE BEGUN TO FILL OVER SNS. THESE CIGS
LOWER TO IFR AS THEY ALSO BEGIN TO AFFECT MRY IN THE EARLY NIGHT.
FOG AND LIFR CIGS ARE EXPECTED INTO THE LATE NIGHT AND LAST THROUGH
MUCH OF THE MORNING WITH LIGHT WINDS. VFR RETURNS INTO TUESDAY
AFTERNOON AS CIGS RETREAT INTO THE BAY AND MODERATE WIND BUILD.
MARINE
(TONIGHT THROUGH NEXT SUNDAY)
ISSUED AT 547 PM PDT MON APR 14 2025
A GENTLE TO MODERATE NORTHWESTERLY BREEZE WILL PERSIST OVER THE
NORTHERN WATERS THROUGH MUCH OF THE WEEK. ACROSS THE SOUTHERN
WATERS, WE WILL SEE A LIGHT TO GENTLE SOUTHERLY BREEZE THROUGH AT
LEAST MIDWEEK. MODERATE SEAS HOLD THROUGH MIDWEEK OR SO, AND THEN
BUILD INTO THE LATTER PORTION OF THE WORK WEEK. NORTHWESTERLY
WINDS WILL INCREASE AS WELL LATE IN THE WEEK AND ANOTHER ROUND OF
SMALL CRAFT ADVISORIES MAY BE NEEDED.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
SHORT TERM...SO
LONG TERM....SO
AVIATION...MURDOCK
MARINE...RGASS
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, X, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
X.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page