348
FXUS66 KMFR 141745
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
1045 AM PDT SUN SEP 14 2025
UPDATED AVIATION DISCUSSION
AVIATION...14/18Z TAFS
A DEPARTING SYSTEM WILL MAINTAIN A MIX OF
LOW END VFR/MVFR CONDITIONS, WITH AREAS OF IFR ALONG THE COAST,
WIDESPREAD MOUNTAIN OBSCURATIONS, AND ISOLATED SHOWERS ACROSS
SOUTHWEST OR THROUGH AROUND 21Z. FROM AROUND 20-21Z ONWARD,
CONDITIONS WILL IMPROVE TO MAINLY VFR AS SHOWERS DIMINISH AND CLOUD
COVER BREAKS UP. SOUTH OF THE OR/CA BORDER, VFR CONDITIONS PREVAIL
AND WILL DO SO THROUGH THE TAF PERIOD.
OFFSHORE FLOW SETS UP TONIGHT AND THIS SHOULD LIMIT THE EXTENT OF
IFR/LIFR DEVELOPMENT ALONG THE COAST AND INTO THE UMPQUA BASIN. WITH
RECENT RAINFALL, HOWEVER, EXPECT AT LEAST PATCHY AREAS OF IFR/LIFR
DEVELOPMENT IN THE COASTAL RIVER VALLEYS TONIGHT INTO EARLY MONDAY
MORNING, WITH VFR EXPECTED ELSEWHERE OVERNIGHT. /BR-Y
PREV DISCUSSION
/ISSUED 641 AM PDT SUN SEP 14 2025/
DISCUSSION...THE MAJORITY OF PRECIPITATION TO OCCUR WITH A FAST
MOVING COLD FRONT OCCURRED OVERNIGHT, INCLUDING ISOLATED
THUNDERSTORMS IN SOUTHERN OREGON. AMOUNTS IN COOS, DOUGLAS, AND
CURRY COUNTIES WERE COMMONLY AROUND 0.15 TO 1.00 INCHES. SHOWERS
WILL LINGER THIS MORNING, GRADUALLY TAPERING OFF THROUGH THE
AFTERNOON.
A PROGRESSIVE PATTERN CONTINUES WITH AN UPPER RIDGE GUIDING
CONDITIONS TO START THE WORK WEEK. THE MAIN IMPACT WILL BE
ANOTHER ROUND OF WARMER TEMPERATURES. EAST WINDS MAY BE WITH WEST
SIDE VALLEYS PEAKING IN THE HIGH 80S TO LOW 90S ON TUESDAY. EAST
SIDE AREAS ARE FORECAST TO BE IN THE LOW TO MID 80S ON TUESDAY AND
WEDNESDAY. FIRE WEATHER CONCERNS DUE TO VERY DRY CONDITIONS AND
GUSTY WINDS REMAIN IN THIS PERIOD AND ARE ADDRESSED IN THE
DISCUSSION BELOW.
AN UPPER TROUGH COULD BRING NEAR-SEASONAL TEMPERATURES TO END NEXT
WEEK. MOST OF THE ACTIVITY WITH THIS TROUGH LOOK TO PASS TO THE
NORTH OF THE AREAS. HOWEVER, SOUTHWEST FLOW AROUND THE TROUGH MAY
ALLOW FOR ISOLATED THUNDERSTORMS IN NORTHERN CALIFORNIA OR EAST OF
THE CASCADES ON FRIDAY AFTERNOON AND EVENING. DETAILS FOR THIS
PERIOD REMAIN COARSE. BEYOND FRIDAY, MODELS CONTINUE TO DIVERGE IN
OVERALL PATTERN. METEOGRAM GUIDANCE GENERALLY INDICATES TEMPERATURES
STAYING AT OR JUST ABOVE SEASONAL LEVELS AND LONG-TERM
PRECIPITATION SIGNALS REMAIN SCRAMBLED. -TAD
MARINE...UPDATED 200 AM PDT SUNDAY, SEPTEMBER 14, 2025...
NORTHWEST SWELL-INFLUENCED SEAS REMAIN BELOW ADVISORY LEVELS
THROUGH THIS AFTERNOON. A THERMAL TROUGH LOOKS TO DEVELOP THIS
AFTERNOON, BRINGING GUSTY NORTHERLY WINDS AND STEEP SEAS SOUTH OF
CAPE BLANCO THIS EVENING THROUGH MONDAY MORNING. STEEP SEAS WILL
BUILD ACROSS ALL WATERS FROM MONDAY MORNING THROUGH TUESDAY
MORNING BEFORE CONDITIONS IMPROVE THROUGH WEDNESDAY MORNING.
ON WEDNESDAY AFTERNOON, WIND-BUILT UNSETTLED SEAS ARE POSSIBLE AS
WELL. GUSTY NORTHERLY WINDS LOOK TO BUILD ACROSS ALL WATERS, WITH
FORECAST GUSTS APPROACHING GALE SPEEDS OVER WATERS SOUTH OF CAPE
BLANCO ON THURSDAY. THIS PERIOD WILL BE WATCHED CLOSELY AS IT
APPROACHES. -TAD
FIRE WEATHER...UPDATED 200 AM PDT SUNDAY, SEPTEMBER 14,
2025...FIRE WEATHER CONCERNS FAIRLY ARE MINIMAL TODAY. A TROUGH
SWINGS THROUGH THE REGION TODAY, BRINGING BENEFICIAL RAINFALL.
HIGHEST RAINFALL AMOUNTS, ISOLATED THUNDERSTORMS, AND BEST CHANCES
FOR WETTING RAINS ARE IN SOUTHERN OREGON THROUGH AROUND 8 AM THIS
MORNING, ESPECIALLY ALONG THE COAST TO THE COAST RANGE AND INTO THE
UMPQUA BASIN.
BEHIND THIS FRONT, UPPER LEVEL RIDGE BUILDS IN AND A THERMAL TROUGH
DEVELOPS ALONG THE COAST. THIS WILL INDUCE A PERIOD OF
EASTERLY/OFFSHORE FLOW AND BRING ABOUT A SHARP WARMING AND DRYING
TREND FOR THE MONDAY-WEDNESDAY PERIOD. EAST TO NORTHEASTERLY WINDS
DEVELOP SUNDAY NIGHT INTO MONDAY MORNING, BUT RECOVERIES WILL REMAIN
ON THE GOOD SIDE. IT'S NOT UNTIL MONDAY NIGHT/TUESDAY MORNING THAT
RECOVERIES REALLY DROP IN TO THE MODERATE TO LOCALLY POOR RANGE.
CURRENTLY, IT LOOKS LIKE RECOVERIES ARE LOWEST ON TUESDAY MORNING,
BUT AS DRIER AIR SPREADS EASTWARD, MORE AREAS WILL SEE MODERATE TO
LOCALLY POOR RECOVERIES FOR WEDNESDAY MORNING AS WELL. CURRENT
GUIDANCE BOTTOMS OUT RH RECOVERIES IN THE 30-40% RANGE (DOWN TO 25%
FOR SOME OF THE HIGHER PEAKS), AND HAS WINDS GUSTING TO 15-20 MPH.
THIS DOESN'T QUITE REACH CRITERIA FOR WATCH/WARNING PRODUCTS, AND
TYPICALLY IT NEEDS TO BE AT LEAST A FEW NIGHTS IN A ROW TO GET THE
RHS TO REALLY DROP LOW ENOUGH. AS SUCH, WE'LL BE MAINTAINING A
HEADLINE FOR THIS EVENT IN THE FIRE WEATHER PLANNING FORECAST
(FWFMFR). MEANWHILE, DAYTIME HUMIDITIES WILL TREND LOWER WITH
TEENS/LOW 20S COMMON ACROSS THE REGION ON TUESDAY. MIN RHS WILL ALSO
TREND HIGHER ON WEDNESDAY AS THE FLOW BECOMES ONSHORE AGAIN.
A WEAK AND DRY FRONT IS EXPECTED TO MOVE INTO THE AREA LATE
WEDNESDAY. THIS MAY RESULT IN SOME ENHANCED AFTERNOON BREEZES FOR
INLAND AREA. OTHERWISE, EXPECT TEMPERATURES TO TREND LESS WARM
WEDNESDAY INTO THURSDAY.
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FROM 5 PM THIS
AFTERNOON TO 5 AM PDT TUESDAY FOR PZZ350-356-370-376.
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