224
FXUS66 KMFR 081309
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
609 AM PDT WED OCT 8 2025
DISCUSSION
CONFIDENCE IS HIGHER THAT OUR WEATHER FOR THE NEXT
WEEK, AND POSSIBLY THE NEXT 10 DAYS, WILL BE DOMINATED BY TWO
BROAD, SLOW-MOVING UPPER LEVEL TROUGHS. THE FIRST TROUGH IS NOW
OFFSHORE OF WASHINGTON AND EXPECTED TO EXIT EAST OF OUR AREA LATE
SATURDAY. THE SECOND TROUGH WILL FOLLOW CLOSELY BEHIND AND FOLLOW
A SIMILAR TRACK SUNDAY INTO WEDNESDAY.
THE FIRST SIGN OF THIS CHANGE TO A LOW PRESSURE DOMINATED PATTERN
IS THE OVERNIGHT INFLUX OF STRATUS INTO COOS AND WESTERN DOUGLAS
COUNTIES. THIS STRATUS IS EXPECTED TO LIFT AND GET SOME BREAKS IN
THE LATE MORNING AND AFTERNOON, WHILE MOST OF OUR AREA SEES A LATE
DAY INCREASE IN MID AND UPPER LEVEL CLOUDS. THERE WILL ALSO BE
SEVERAL DEGREES OF COOLING, COMPARED TO YESTERDAY AFTERNOON, AND
GUSTY, BREEZY SOUTHWEST TO WEST AFTERNOON WINDS. THESE WINDS WILL
BE STRONGEST EAST OF THE CASCADES. LATE IN THE DAY AND OVERNIGHT,
THOUGH PARTICULARLY IN THE EVENING, ISOLATED SHOWERS MAY DEVELOP,
WITH THE HIGHEST PROBABILITY OVER THE CASCADES.
AFTER TODAY, ALL OF OUR AREA WILL HAVE TEMPERATURES TRENDING MUCH
COOLER, WITH RAIN CHANCES, AND PERIODS OF GUSTY WINDS. RAIN
CHANCES ARE EXPECTED TO BE HIGHEST ON FRIDAY AND MONDAY. THIS
INCLUDES SLIGHT CHANCES OF THUNDERSTORMS FOR PORTIONS OF OUR AREA
ON BOTH OF THOSE DAYS.
OUR WEATHER TOMORROW WILL STILL HAVE SOME SIMILARITY TO TODAY, BUT
WITH ADDITIONAL COOLING, A SHIFT TO GUSTY SOUTH WINDS FOR THE
SHASTA VALLEY AND EAST SIDE IN THE AFTERNOON, AND A GENERAL
INCREASE IN CLOUD COVER WITH A HIGHER PROBABILITY OF MAINLY LIGHT
SHOWERS, MAINLY FROM THE COAST TO THE CASCADES.
THE MAIN FRONT IS EXPECTED TO TRACK INLAND ON FRIDAY MORNING AND
LOOKS TO WEAKEN SLIGHTLY BEFORE IT TRACKS ACROSS THE EAST SIDE
LATE IN THE DAY INTO FRIDAY NIGHT. RAINFALL AMOUNTS ARE LIKELY TO
BE HIGHEST FOR COOS AND WESTERN SISKIYOU COUNTIES FROM AROUND A
HALF INCH TO AN INCH AND A QUARTER. MEANTIME, AMOUNTS OF A QUARTER
TO A HALF INCH ARE EXPECTED TO BE COMMON ELSEWHERE FROM THE COAST
TO THE CASCADES, AND LESS THAN A QUARTER OF AN INCH ON THE EAST
SIDE.
SATURDAY SHOULD BE CHARACTERIZED BY THE TROUGH STARTING THE DAY
OVER OUR AREA WITH ANOTHER DISTURBANCE IN THE NORTHWEST FLOW ALOFT
BRINGING LIGHTER SHOWERS. NEW PRECIPITATION AMOUNTS ARE EXPECTED
TO BE LESS THAN A QUARTER OF AN INCH, AND FOR MANY SITES WILL BE
LESS THAN A TENTH OF AN INCH. THE HIGHEST AMOUNTS ARE EXPECTED
FOR WEST TO NORTHWEST FACING SLOPES, INCLUDING KALMIOPSIS
WILDERNESS AND THE CASCADES.
UNCERTAINTY IN THE FORECAST DETAILS INCREASES BY A NOTCH FOR
SUNDAY WITH DIFFERENCES IN THE ARRIVAL TIME AND SOUTHERN EXTENT OF
THE STRONGER, WETTER PORTION OF A COLD FRONT. THIS FRONT WILL BE
ASSOCIATED WITH THE SECOND TROUGH, WITH THE TROUGH EXPECTED TO
MOVE OFF THE WASHINGTON COAST DURING THE DAY. AS SUCH, THE HIGHEST
PROBABILITY OF RAIN WILL BE FOR COOS, DOUGLAS, AND NORTHERN
KLAMATH COUNTIES, AND AREAS NORTHWARD.
MODELS AGREE THAT THIS SECOND TROUGH WILL STILL AFFECT OUR AREA
MONDAY THROUGH AT LEAST EARLY TUESDAY. BUT, A SLOWER PROGRESSION
IS POSSIBLE. THE POSITION OF THE TROUGH WILL DICTATE RAIN AND
THUNDER CHANCES, BUT THERE IS SUPPORT FOR EXPECTING RAINFALL
AMOUNTS ON MONDAY TO RESEMBLE THOSE FROM FRIDAY.
A COOL, SHOWERY AIRMASS IS THE MOST LIKELY SCENARIO FOR TUESDAY
INTO WEDNESDAY. HIGH TEMPERATURES AROUND DAY 6/7 ARE EXPECTED TO
BE AROUND 20 DEGREES COLDER THAN THOSE OF YESTERDAY. -DW
AVIATION...08/12Z TAFS
LIGHT, DOWNSLOPE NORTHEAST WINDS ALONG THE
CURRY COUNTY COAST HAVE PRODUCED ENOUGH DRYING TO PRODUCE A BREAK IN
THE STRATUS. MVFR STRATUS DOES EXTEND OVER THE COAST AND COASTAL
WATERS FROM CAPE BLANCO NORTHWARD, AND ACROSS COOS AND WESTERN
DOUGLAS COUNTIES. THIS INCLUDES THE COQUILLE, CAMAS, AND LOWER
UMPQUA VALLEYS. THIS CONDITION IS EXPECTED TO PERSIST THROUGH AROUND
18Z THIS MORNING, BEFORE THE COASTAL STRATUS LIFTS, EXPECTED TO RISE
JUST ENOUGH TO BECOME VFR. ALSO, THE MVFR STRATUS MAY BRIEFLY REACH
ROSEBURG/KRBG AROUND 14-17Z THIS MORNING.
ELSEWHERE, CLEAR SKIES ARE EXPECTED TO PERSIST INTO THIS AFTERNOON.
A CHANGE IN OUR WEATHER WILL BE APPARENT ACROSS THE AREA LATER THIS
AFTERNOON WITH GUSTY SOUTHWEST TO WEST BREEZES AND INCREASING MID
AND HIGH LEVEL CLOUDS. BY 00Z, EARLY THIS EVENING, WEAK INSTABILITY
MAY BE SUFFICIENT TO GENERATE A FEW SHOWERS OVER AND NEAR THE
CASCADES.
MVFR IS EXPECTED TO RETURN TO THE COAST AROUND 06Z THIS EVENING, AND
CONTINUE INTO THURSDAY MORNING. -DW
MARINE...UPDATED 200 AM PDT WEDNESDAY, OCTOBER 8, 2025
A
COMBINATION OF NORTHERLY WINDS AND NORTHWEST SWELL WILL CONTINUE TO
BUILD STEEP SEAS THROUGH EARLY THURSDAY MORNING. THE INCREASE WILL
BE MODEST, WITH CONDITIONS JUST BARELY SUFFICIENT TO WARRANT THE
SMALL CRAFT ADVISORY.
A LOW PRESSURE SYSTEM LOOKS TO BRING SHOWERS FROM THURSDAY INTO
SATURDAY. THE FIRST ASSOCIATED FRONT WILL BE WEAK, THOUGH WITH A
SHIFT TO SOUTHERLY WINDS EXPECTED EARLY THURSDAY. THE DECREASE IN
WINDS FOR THURSDAY WILL RESULT IN A LONGER WAVE PERIOD. A STRONGER
DISTURBANCE EARLY FRIDAY INTO FRIDAY NIGHT WILL BE ACCOMPANIED BY A
SLIGHT CHANCE OF THUNDERSTORMS, AND MAY BRING A RETURN OF STEEP SEAS
AND ADVISORY STRENGTH SOUTHERLY WINDS.
SEAS BECOME SWELL DOMINATED SATURDAY THEN BUILD SUNDAY, AHEAD OF
ANOTHER LOW PRESSURE SYSTEM. NORTHERLY WINDS ARE EXPECTED BY
SATURDAY NIGHT WITH RAIN CHANCES CONTINUING. THE STRONGEST FRONT
WITH THIS NEXT SYSTEM IS LIKELY MONDAY INTO MONDAY EVENING, WITH
ANOTHER SLIGHT CHANCE OF THUNDERSTORMS AND A POSSIBLE RETURN OF
STEEP SEAS. -DW
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 5 AM PDT THURSDAY
FOR PZZ350-356-370-376.
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