678
FXUS66 KMFR 271757
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
1057 AM PDT TUE OCT 27 2026
UPDATED AVIATION DISCUSSION
AVIATION...27/18Z TAFS
A TROUGH IS MOVING THROUGH AREAS NEAR
AND WEST OF THE CASCADES LATE THIS MORNING WITH MOST OF THE
PRECIPITATION OCCURRING IN SW OREGON. LIGHT TO MODERATE RAIN,
MVFR CEILINGS AND HIGHER TERRAIN OBSCURATION WILL ACCOMPANY THIS
DISTURBANCE WITH LOCAL IFR CONDITIONS AT TIMES IN AREAS OF
HEAVIER PRECIPITATION. AS THIS SYSTEM SHIFTS EAST OF THE CASCADES
THIS AFTERNOON, PRECIPITATION WILL BECOME MORE SPARSE/SHOWERY AND
CONDITIONS SHOULD IMPROVE. CONDITIONS SHOULD MOSTLY REMAIN VFR IN
SOUTH CENTRAL OREGON AND FAR NORTHERN CALIFORNIA, THOUGH MAY
BRIEFLY LOWER TO MVFR IN ANY SHOWER. CONDITIONS SHOULD IMPROVE TO
VFR ALL AREAS THIS EVENING.
LATE TONIGHT INTO WEDNESDAY MORNING, AFTER 09Z, ANOTHER WEAKER
TROUGH WILL BRING LIGHT RAIN TO THE COAST NORTH OF CAPE BLANCO WITH
A SIMILAR MIX OF IFR/MVFR FOR COOS AND DOUGLAS COUNTIES. VFR WILL
PERSIST ELSEWHERE, EXCEPT THERE IS A 20-30% POSSIBILITY OF IFR FOG
IN SOME VALLEYS AROUND SUNRISE. -SPILDE
PREV DISCUSSION
/ISSUED 559 AM PDT TUE OCT 27 2026/
KEY MESSAGES...
* PERSISTENT LOW PRESSURE THIS WEEK BRINGS SEASONABLY ACTIVE
WEATHER WITH MAINLY LOW IMPACTS.
* THE MOST SIGNIFICANT RAINFALL OF THE REMAINDER OF THE WEEK WILL
BE MAINLY ALONG AND WEST OF THE CASCADES THIS MORNING. SNOW
LEVELS AROUND 5000-5500 FT, WITH A COUPLE OF INCHES OF SNOW
POSSIBLE AROUND THE DIAMOND LAKE/CRATER LAKE AREA. A FEW LIGHTER
SHOWERS LINGER THIS AFTERNOON.
* TEMPERATURES RELATIVELY STEADY THROUGH THE WEEK, FLUCTUATING IN
A RANGE FROM AROUND 10 DEGREES BELOW NORMAL TO NEAR NORMAL.
* EXCELLENT MODEL AGREEMENT THROUGH FRIDAY WITH OCCASIONAL LIGHT
SHOWER CHANCES, MAINLY FOR COOS AND DOUGLAS COUNTIES NORTHWARD
DURING WEDNESDAY AND ALSO THURSDAY NIGHT.
* EITHER A WEAK OR VERY WEAK SYSTEM MOVES INLAND ON SATURDAY.
LIGHT SHOWER CHANCES ON SATURDAY WILL BE HIGHEST AT THE COAST,
POSSIBLY EXTENDING INLAND DURING THE AFTERNOON OR EVENING.
* HIGH PRESSURE WILL LIKELY BRING DRYING AND MODEST WARMING FOR
SUNDAY THROUGH TUESDAY.
DISCUSSION...LOW PRESSURE OFF THE CENTRAL OREGON COAST WILL TRACK
EASTWARD TODAY. RAINFALL WILL BE FOCUSED ON SOUTHWEST OREGON
THROUGH AROUND 10 AM THIS MORNING, THEN LIGHTER SHOWERS TAPER OFF
DURING THE REMAINDER OF THE DAY. AROUND A QUARTER TO HALF INCH OF
RAIN IS EXPECTED FOR COOS AND DOUGLAS COUNTIES, WITH UP TO A
QUARTER OF AN INCH FOR CURRY COUNTY, UP TO A TENTH OF AN INCH FOR
JOSEPHINE AND JACKSON COUNTIES, AND A MEASUREABLE AMOUNT FOR
NORTHERN KLAMATH AND FAR WESTERN SISKIYOU COUNTIES. THIS INCLUDES
UP TO 2 INCHES OF SNOW FOR THE SOUTHERN OREGON CASCADES WITH A
SNOW LEVEL AROUND 5500 FEET FALLING TO 5000 FEET.
A BROADER AREA OF LOW PRESSURE, NOW OVER NORTHERN BRITISH
COLUMBIA, WILL RETROGRADE SLIGHTLY, TRACKING SOUTH-SOUTHWEST
TOWARD VANCOUVER ISLAND BY TOMORROW/WEDNESDAY. ASSOCIATED SHOWERS
IN THE ONSHORE FLOW PATTERN WILL BE FOCUSED NORTH OF OUR AREA.
BUT, COOS AND DOUGLAS COUNTIES SHOULD RECEIVE A MEASUREABLE AMOUNT
OF SHOWERS UNDER PERSISTENT CLOUD COVER. ELSEWHERE, BREAKS IN THE
CLOUD COVER ARE EXPECTED AND SHOULD ALLOW FOR HIGH TEMPERATURES
TO REACH A FEW TO SEVERAL DEGREES HIGHER THAN TODAY.
THE LOW WILL MEANDER A BIT FARTHER SOUTH ON THURSDAY, WITH OUR
REGION LIKELY TO BE BETWEEN SHORTWAVES FOR A REDUCED CHANCE OF
LIGHT COASTAL SHOWERS. COMPARED TO THE GFS, THE ECMWF DOES
INDICATE A BIT MORE LOW LEVEL MOISTURE THAT WOULD BE SUFFICIENT TO
GENERATE VERY LIGHT SHOWERS NORTH OF CAPE BLANCO. THE BLENDED 40%
PROBABILITY OF RAIN AND TRACE TO A BARELY MEASUREABLE HUNDREDTH
OR SO IS APPROPRIATE.
THE LOW IS EXPECTED TO REMAIN OFFSHORE OF WASHINGTON AND NORTHERN
OREGON, WITH A SLIGHT BACKING TO MORE OF A DUE SOUTHWEST FLOW
ALOFT ON THURSDAY NIGHT THROUGH FRIDAY NIGHT. THIS WILL KEEP THE
MORE FAVORABLE DYNAMICS AND DEEPER MOISTURE AIMED NORTH OF OUR
AREA. THE RESULT IS A FRIDAY THAT SHOULD RESEMBLE THURSDAY.
FOR NOW, THE STORY FOR SATURDAY IS MUCH THE SAME AS IT WAS
YESTERDAY. UNCERTAINTY INCREASES A BIT, ENOUGH TO MAKE THE
DIFFERENCE BETWEEN WHETHER LIGHT OR VERY LIGHT SHOWERS REMAIN
CONFINED TO THE COAST, OR EXTEND TO THE CASCADES WITH A SLIGHT
CHANCE POSSIBLY WARRANTED FOR THE EAST SIDE. FOR THE DAYLIGHT
HOURS, THE PROBABILITY WILL BE HIGHEST FOR (AND POSSIBLY LIMITED
TO) THE COAST. THE ECMWF SUITE OF SOLUTIONS INDICATING A HIGHER
PROBABILITY OF WEST SIDE FOCUSED RAIN, A SHARPER TROUGH, THAN THE
GEFS. THIS WOULD MEAN AROUND 0.05 TO 0.10 INCHES FOR THE COAST
RATHER THAN A TRACE TO 0.02 INCHES. TOWARD SUNSET INTO THE EVENING,
RAIN CHANCES COULD SPREAD FARTHER INLAND. THIS UNCERTAINTY IS
EXPRESSED BY 20-30% RAIN CHANCES BEING MAINLY WEST AND NORTH OF
JACKSON COUNTY FOR THE AFTERNOON, AHEAD OF A MORE WIDESPREAD
SLIGHT CHANCE TO CHANCE FOR THE EVENING.
DESPITE THE DIFFERENCES IN STRENGTH, MODELS ARE IN GOOD AGREEMENT
ON SLIGHT RAIN CHANCES LINGERING EAST OF THE CASCADES LATE
SATURDAY NIGHT AHEAD OF RIDGING EARLY NEXT WEEK. THE RIDGE WILL
PROVIDE DRYING AND MODEST WARMING SUNDAY INTO TUESDAY. FROM LATE
DAY 7 THROUGH DAY 10, MODEL UNCERTAINTY QUICKLY INCREASES WITH A
NEAR EVEN SPLIT BETWEEN WHETHER RIDGING WILL LINGER INTO MID-WEEK,
OR SHIFT TO THE ROCKIES WITH A RETURN TO WET WEATHER FOR THE
PACIFIC NORTHWEST.
MARINE...UPDATED 130 AM PDT TUESDAY, OCTOBER 27, 2026...UNSETTLED
WEATHER WITH OCCASIONAL SHOWERS WILL CONTINUE THROUGH THE WEEK.
WINDS ARE EXPECTED TO REMAIN BELOW ADVISORY STRENGTH. A SERIES OF
SEASONABLY WEAK DISTURBANCES WILL PRODUCE THE STRONGEST NORTHWEST
WINDS IN THE WASHINGTON AND NORTHERN OREGON OFFSHORE WATERS, WHICH
WILL PUSH FRESH SWELL INTO THE SOUTHERN OREGON WATERS. WAVE HEIGHTS
WILL BE JUST HIGH ENOUGH AND STEEP ENOUGH TO REACH SMALL CRAFT
ADVISORY CRITERIA. FRESH WEST-NORTHWEST SWELL DOMINATED SEAS
CONTINUE FOR OUR AREA THROUGH THIS EVENING. THE ACTIVE PATTERN IS
EXPECTED TO PERSIST LATE IN THE WEEK WITH SLIGHT, GRADUAL
IMPROVEMENT IN CONDITIONS. THE OUTLOOK IS THAT A LONG PERIOD WEST-
NORTHWEST SWELL MAY BUILD FROM 2 FT AT 21 SECONDS LATE SUNDAY TO
6-8 FT AT 17 SECONDS ON MONDAY.
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 5 PM PDT THIS
AFTERNOON FOR PZZ350-356-370-376.
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