489
FXUS66 KMTR 140448
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
948 PM PDT SUN APR 13 2025
..NEW AVIATION, MARINE
SYNOPSIS
ISSUED AT 1246 PM PDT SUN APR 13 2025
QUIET WEATHER IS ON TAP WITH A WARMING TREND STARTING TODAY AND
CONTINUING INTO THE EARLY PORTION OF THE WEEK. FOR MIDWEEK TO LATE
WEEK, A BRIEF COOLING TREND IS EXPECTED WITH THE POTENTIAL FOR WARMER
WEATHER RETURNING FOR THE WEEKEND.
UPDATE
ISSUED AT 845 PM PDT SUN APR 13 2025
THE FORECAST REMAINS ON TRACK WITH NO UPDATES NEEDED THIS EVENING.
SATELLITE IMAGERY SHOWS AN OTTER EDDY IN THE MONTEREY BAY WITH
STRATUS GENERALLY SHIFTING TO THE SOUTH. AN INTERESTING UPPER-
LEVEL PATTERN WILL YIELD INTERESTING STRATUS COVERAGE TONIGHT.
WITH THE REGION BEING LARGELY UNDER SPLIT FLOW WITH A CUTOFF-LOW
UNDERCUTTING A SHORTWAVE RIDGE, THE SMALLEST AMOUNT OF FORCING
WILL DICTATE STRATUS COVERAGE. AS SUCH, HREF AND NBM SUGGEST THAT
STRATUS WILL MAKE A TRIUMPHANT RETURN IN THE EARLY MORNING HOURS OF
MONDAY, PRIMARILY TO COASTAL LOCATIONS.
SARMENT
SHORT TERM
(THIS EVENING THROUGH MONDAY)
ISSUED AT 1246 PM PDT SUN APR 13 2025
SATELLITE SHOWS MOSTLY CLEAR SKIES THROUGHOUT THE REGION.
TEMPERATURES REPORTED ABOUT 5-10 DEGREES ABOVE NORMAL TODAY, WHICH
IS ON TRACK AS THE UPPER LEVEL RIDGING PROMOTES THE WARMING TREND
GOING INTO MONDAY. TONIGHT TEMPERATURES IS EXPECTED TO DROP TO
MOSTLY 50S, BUT MAX TEMPERATURES ON MONDAY ARE EXPECTED TO REACH MID
70S TO MID 80S IN THE INTERIOR REGIONS, AND UPPER 60S TO LOW 70S
ALONG THE COAST. KEEP IN MIND THAT THE WARM TEMPERATURES HAVE PUT
MOST OF OUR INLAND AREAS UNDER A MINOR HEATRISK FOR THOSE EXTREMELY
SENSITIVE TO HEAT. PLEASE TAKE THE PROPER PRECAUTIONS AND STAY
HYDRATED.
LONG TERM
(MONDAY NIGHT THROUGH NEXT SATURDAY)
ISSUED AT 1246 PM PDT SUN APR 13 2025
THE UPPER LEVEL PATTERN BEGINS TO CHANGE ON TUESDAY AS A LOW
PRESSURE SYSTEM THAT SITS OFF THE COAST OF SOUTHERN CA, STARTS TO
GRADUALLY MOVE NORTHEAST AND PUSH THE RIDGE OUT TO THE EAST. THIS
WILL ALLOW SOME COOLER TEMPERATURES, ONSHORE WINDS, AND INCREASE IN
CLOUD COVER. NBM CONTINUES TO SHOW CHANCES FOR THUNDERSTORMS IS LESS
THAN 10% AND THE GFS AND NAM SHOWS PWAT VALUES REMAINING UNDER 0.80"
FOR OUR AREA ON TUESDAY THROUGH THURSDAY, BUT SPC DOES HAVE MOST OF
THE EASTERN PORTION OF CA HIGHLIGHTED FOR POSSIBLE ISOLATED
THUNDERSTORMS DUE TO INSTABILITY FROM THE COLD AIR MASS AND DAYTIME
HEATING. AS WE GET CLOSER TO MID-WEEK AND CONTINUE TO MONITOR THE
PLACEMENT OF THE TROUGH, CONFIDENCE WILL INCREASE ON DETERMINING THE
CHANCES FOR THUNDERSTORMS. CLUSTER ANALYSIS DOES FAVOR A RIDGE
PUSHING IN FROM THE EASTERN PACIFIC, BRINGING ANOTHER CHANCE FOR
WARMER TEMPERATURES AND DRIER CONDITION THIS UPCOMING WEEKEND.
AVIATION
(06Z TAFS)
ISSUED AT 947 PM PDT SUN APR 13 2025
WINDS CONTINUE TO REDUCE INTO THE NIGHT AND LOOK TO BECOME LIGHT
FOR MOST AREAS. CLOUD COVER WILL MOVE SLOWLY INTO THE REGION FROM
THE SOUTH OVERNIGHT. THIS WILL LEAD TO IFR CIGS FILLING OVER HAF
AND SNS IN THE LATE NIGHT, AND SOME CIGS AFFECTING MRY FOR MONDAY
MORNING. THE NORTH BAY TERMINALS LOOK TO SEE MOMENTS OF FOG INTO
EARLY MONDAY MORNING, AND LASTING THROUGH THE MID MORNING. WHILE
ALL OTHER TERMINALS LOOK TO SEE VFR BY THE END OF MONDAY MORNING,
IFR CIGS CONTINUE FOR HAF BEYOND THE TAF PERIOD. MODERATE WINDS
RETURN FOR MONDAY AFTERNOON, BUT WIND DIRECTIONS WILL BE MORE
AFFECTED BY LOCALIZED EFFECTS. IFR CIGS WILL BUILD INLAND INTO
THAT EVENING.
VICINITY OF SFO...VFR THROUGH THE TAF PERIOD. EXPECT WINDS TO REDUCE
INTO THE EARLY NIGHT BECOMING LIGHT THROUGH THE LATE MORNING. WEST
WINDS WILL INCREASE AGAIN INTO MONDAY AFTERNOON, BUT ONLY TO
MODERATE SPEEDS BEFORE BECOMING LIGHT AGAIN INTO THAT NIGHT.
SFO BRIDGE APPROACH...SIMILAR TO SFO
MONTEREY BAY TERMINALS...WINDS ARE BECOMING LIGHT AROUND THE
TERMINALS. CLOUD COVER IS ROTATING AROUND THE MONTEREY BAY AROUND AN
EDDY, TRANSPORTING CLOUD COVER COUNTER-CLOCKWISE. SAID EDDY PUSHED
IFR CIGS INTO SNS BUT ARE NOW PULLING THEM TOWARD THE NORTHERN
PORTIONS OF THE MONTEREY BAY. LOW CLOUDS MOVE UP THE BIG SUR COAST
AND INTO THE MONTEREY BAY IN THE LATE NIGHT AS THE OSCILLATION
BEGINS TO FALL APART. MRY WILL INITIALLY BE SHELTERED FROM THESE
CLOUDS, WITH SNS FILLING IN THE LATE NIGHT THROUGH MUCH OF THE
MORNING. INCONSISTENT CIGS LOOK TO AFFECT MRY IN THE EARLY TO LATE
MORNING BEFORE CLOUD COVER RETREATS BACK TO INTO THE BAY ITSELF.
AS TERMINALS RETURN TO VFR, MODERATE WINDS BUILD FOR MONDAY
AFTERNOON. IFR CIGS RETURN IN THE EARLY EVENING ON MONDAY AS WINDS
BECOME LIGHT
MARINE
(TONIGHT THROUGH NEXT SATURDAY)
ISSUED AT 947 PM PDT SUN APR 13 2025
WINDS WEAKEN INTO THE NIGHT, BUT BECOME MODERATE AGAIN INTO
MONDAY. MODERATE SEAS OF 7 TO 10 FEET WILL GRADUALLY SUBSIDE
THROUGHOUT THE NIGHT, WITH WAVES FALLING BELOW SMALL CRAFT
CRITERIA. SEAS BUILD TOWARD THE LATTER HALF OF THE WORK WEEK WITH
BREEZY WINDS ARRIVING LATER THAT WEEKEND.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
SHORT TERM...SO
LONG TERM....SO
AVIATION...MURDOCK
MARINE...MURDOCK
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