235
FXUS66 KMFR 131222
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
422 AM PST SAT DEC 13 2025
DISCUSSION
THIS MORNING, SATELLITE IMAGERY AND SURFACE
OBSERVATIONS SHOW THAT FOG AND LOW STRATUS HAS FILLED THE VALLEYS
WEST OF THE CASCADES ONCE AGAIN. HIGHER CLOUDS OVERHEAD ARE ALSO
DISPLAYING A CLOCKWISE ROTATION, CENTERED SOMEWHERE OVER LAKE
COUNTY; SHOWING THE RIDGE AXIS IS SHIFTING TO THE EAST. THIS RIDGE
REMAINS IN CONTROL OVER THE AREA, BUT IT WILL SOON LOSE THAT
CONTROL AS THE STORM TRACK MAKES A SHIFT TOWARDS SOUTHERN OREGON
AND FAR NORTHERN CALIFORNIA IN JUST A FEW MORE DAYS.
WITH THE RIDGE STILL OVERHEAD, DRY AND MILD WEATHER CONTINUES (WHERE
LOW CLOUDS AND FOG ARE ABSENT). THE LOW CLOUDS AND FOG IN THE
WEST SIDE VALLEYS COULD BECOME DENSE IN PLACES, ESPECIALLY AROUND
SUNRISE, AND WILL BE SLOW TO ERODE/LIFT, WHICH WILL KEEP
AFTERNOON TEMPERATURES IN CHECK AGAIN TODAY. IT'S NOT OUT OF THE
QUESTION THAT FOG AND LOW STRATUS IN SOME VALLEYS WILL PERSIST
ALL THE WAY THROUGH THE AFTERNOON AS WELL, AND NEVER CLEAR BEFORE
SETTLING SOLIDLY IN AGAIN TONIGHT.
THE UPPER RIDGE WILL WEAKEN SLIGHTLY AS A WEAK FRONT MOVES IN FROM
THE WEST SUNDAY. GIVEN THE WEAK SHORTWAVE AND SURFACE FRONT WILL
BE RUNNING INTO THE STRONGER UPPER RIDGING, THE MOST LIKELY
SCENARIO IS THE FRONT WILL WEAKEN AND DISSIPATE AS IT REACHES THE
COAST SUNDAY AFTERNOON, WITH MAYBE SOME DRIZZLE ALONG THE COAST
NORTH OF CAPE BLANCO, BUT MEASURABLE RAIN IS UNLIKELY.
A SECOND FRONT THEN ARRIVES QUICKLY ON THE HEELS OF THE
DISSIPATING ONE, ARRIVING SUNDAY NIGHT INTO MONDAY WITH RAIN AND
GUSTY WINDS. THIS WILL BE A WARM SYSTEM, AND SNOW LEVELS WILL BE
RATHER HIGH, CLOSE TO 10000 FT, SO NO WINTER IMPACTS ARE EXPECTED.
THAT BEING SAID, ANOTHER POTENT FRONT WITH PLENTY OF WIND AND
PRECIPITATION ARRIVES TUESDAY, AND THIS ONE WILL INTRODUCE COLDER
AIR, LOWERING SNOW LEVELS TO BELOW 4000 FEET BY WEDNESDAY
EVENING. A SERIES OF FRONTS WILL THEN CONTINUE TO IMPACT THE AREA,
ONE AFTER THE OTHER, FOR THE REST OF THE WEEK. DETAILS ON EACH
SYSTEM ARE UNCERTAIN, BUT WITH PLENTY OF PRECIPITATION, AND SNOW
LEVELS DOWN TO OR BELOW PASS LEVELS, WINTER IMPACTS WILL BECOME A
CONCERN. ALL IN ALL, IT APPEARS THAT THE WEATHER WILL BECOME
RATHER BUSY AROUND HERE, JUST IN TIME FOR HOLIDAY TRAVEL.
LOOKING BEYOND NEXT WEEK LEADING UP TO CHRISTMAS HOLIDAY, THERE'S
INCREASING EVIDENCE THAT'S BEING SUPPORTED BY THE ECMWF, GEFS
ENSEMBLE MEANS AND CLUSTERS, WE'LL BE HEADING INTO A COLDER AND
WET PATTERN WITH STORMS ORIGINATING FROM THE GULF OF ALASKA AS WE
GET TOWARDS THE CHRISTMAS HOLIDAY. -BPN
AVIATION...13/12Z TAFS
VERY LITTLE CHANGE IN THE PATTERN IS
LIKELY IN THE NEXT 24 HOURS. AREAS OF LOW STRATUS AND FOG ARE
PRESENT IN VALLEYS WEST OF THE CASCADES, RESULTING IN IFR/LIFR
CONDITIONS AT MEDFORD, ROSEBURG, AND OTHER AREA TERMINALS. THESE
CONDITIONS WILL PERSIST THROUGH 18-20Z SATURDAY. SOME AREAS, SUCH AS
MEDFORD AND GRANTS PASS MAY SEE LITTLE OR NO CLEARING, AND JUST SEE
CEILINGS LIFT HIGHER LATE IN THE AFTERNOON TO MVFR.
ALONG THE COAST AND JUST OFFSHORE. VFR CONDITIONS ARE LIKELY TO
PERSIST, BUT SOME LOCALIZED FOG AND STRATUS IS POSSIBLE.
EAST OF THE CASCADES, GUIDANCE SUGGEST FREEZING FOG AND LOW VERTICAL
VISIBILITY COULD DEVELOP AGAIN IN THE KLAMATH BASIN, INCLUDING
KLAMATH FALLS EARLY THIS MORNING, WHICH WOULD QUICKLY CLEAR TO VFR
BY MID TO LATE MORNING. -BPN
MARINE...UPDATED 200 AM PST SATURDAY, DECEMBER 13, 2025
WINDS
SHIFT TOT HE SOUTH TODAY, THEN INCREASE THROUGH SUNDAY AS A FRONTAL
SYSTEM APPROACHES THE AREA. CONDITIONS ARE LIKELY TO REMAIN BELOW
ADVISORY CRITERIA THROUGH SUNDAY AFTERNOON, BUT A BRIEF PERIOD OF
STEEP SEAS IS POSSIBLE NORTH OF CAPE ARAGO EARLY SUNDAY.
WORSENING CONDITIONS ARE EXPECTED LATE SUNDAY INTO MONDAY AS LOW
PRESSURE DEEPENS OVER THE NORTH PACIFIC AND A COLD FRONT SWINGS
THROUGH THE WATERS SUNDAY NIGHT INTO MONDAY. MORE WIDESPREAD
ADVISORY LEVEL CONDITIONS ARE EXPECTED TO RETURN LATE SUNDAY INTO
MONDAY, WITH GALES AND VERY STEEP SEAS POSSIBLE BY EARLY MONDAY
MORNING. ADDITIONAL FRONTAL SYSTEMS WILL MAINTAIN ACTIVE WEATHER
WITH ELEVATED WINDS AND SEAS THROUGH NEXT WEEK. -BPN
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FROM 1 PM SUNDAY TO 1
AM PST MONDAY FOR PZZ350-356-370-376.
GALE WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY EVENING FOR
PZZ350-356-370-376.
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