520
FXUS66 KMFR 291811
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
1111 AM PDT WED APR 29 2026
..UPDATED AVIATION DISCUSSION FOR 18Z TAFS
AVIATION...29/18Z TAFS
LINGERING CLOUDS ARE CLEARING OUT OF THE
UMPQUA VALLEY, LEADING TO VFR LEVELS ACROSS THE AREA UNDER A STABLE
UPPER PATTERN. GUSTY WINDS ARE EXPECTED ALONG THE OREGON COAST THIS
AFTERNOON BEFORE EASING IN THE EVENING, WITH MARINE STRATUS BRINGING
MVFR LEVELS BY EARLY THURSDAY MORNING. VFR LEVELS LOOK TO CONTINUE
FOR OTHER AREAS THROUGH THE TAF PERIOD. -TAD
PREV DISCUSSION
/ISSUED 333 AM PDT WED APR 29 2026/
KEY MESSAGES...
-UPPER RIDGING BUILDS INTO THE AREA TODAY RESULTING IN ABOVE
NORMAL WARMTH THROUGH LATE WEEK.
-ABOVE NORMAL TEMPS LIKELY CONTINUE THIS WEEKEND.
-UPPER TROUGH FORMS INTO A CLOSED LOW OFFSHORE FRIDAY.
-SHOWER AND T-STORM CHANCES INCREASE FRIDAY/SATURDAY, PEAK
SUNDAY/MONDAY AS THE LOW MOVES ONSHORE INTO CALIFORNIA.
-COOLER TEMPERATURES MONDAY/TUESDAY; SHOWERS/STORMS LINGER,
ESPECIALLY CASCADES EASTWARD TUESDAY.
-UPPER RIDGE REBUILDS BY MID NEXT WEEK.
DISCUSSION...HIGH PRESSURE ALOFT WILL BUILD INTO THE AREA TODAY.
THERE IS STILL A WEAK TROUGH THAT WILL SWING DOWN EAST OF THE
CASCADES AND THIS COULD LEAD TO SOME CUMULUS OVER THE EAST SIDE
ALONG WITH SOME VIRGA, BUT PRECIPITATION CHANCES ARE LOW (10% OR
LESS). OTHER THAN SOME LOW CLOUDS FOR COASTAL VALLEYS AND THE
UMPQUA BASIN THIS MORNING, EXPECT MAINLY SUNNY SKIES ELSEWHERE
TODAY. FOR THE AREA AS A WHOLE, HIGH TEMPERATURES WILL BE A FEW
TO SEVERAL DEGREES HIGHER THAN YESTERDAY. WITH A THERMAL TROUGH
SETTING UP IN NORCAL, WE EXPECT SOME BREEZY NORTH WINDS ALONG THE
COAST IN THE AFTERNOON/EVENING.
THE RIDGE WILL MOVE IN OVERHEAD ON THURSDAY AND THEN PUSH INLAND
INTO THE INTERMOUNTAIN WEST AND THE GREAT BASIN ON FRIDAY. THIS
WILL MAINTAIN THE WARMTH IN OUR AREA WITH HIGH TEMPS GENERALLY
5-15F ABOVE NORMAL. WE'D LIKE TO REMIND EVERYONE THAT EVEN WHEN
THE AIR IS WARM, AREA WATERWAYS ARE STILL QUITE COLD THIS TIME OF
YEAR. WATER TEMPERATURES ARE ONLY IN THE UPPER 40S AND 50S! SO,
ALWAYS WEAR A LIFE JACKET, DON'T SWIM ALONE AND HAVE A FLOTATION
DEVICE READY JUST IN CASE.
MEANWHILE, AN UPPER TROUGH IN THE NORTHEAST PACIFIC WILL BE
"SQUEEZED" SOUTHEASTWARD ALONG 130W AS ANOTHER STRONG RIDGE
AMPLIFIES OUT NEAR 140W. THIS WILL CAUSE THE TROUGH TO DEVELOP
INTO A CLOSED LOW OFF THE PACNW FRIDAY, WHICH WILL SETTLE
SOUTHWARD AND BE OFFSHORE OF THE CALIFORNIA COAST THIS WEEKEND.
THIS WILL SET UP A "REX BLOCK" (HIGH OVER LOW) THAT WILL LINGER
OVER THE WEST INTO NEXT WEEK. MOVEMENT OF WEATHER SYSTEMS IN THIS
TYPE OF REGIME WILL BE SLOW. AREAS FARTHER TO THE NORTH AND CLOSER
TO THE UPPER HIGH (NORTHERN OREGON AND WASHINGTON) WILL LARGELY
MAINTAIN A WARM, DRY PATTERN. HOWEVER, AREAS FARTHER SOUTH AND
CLOSER TO THE CLOSED LOW OFFSHORE, WILL SEE A SURGE IN MOISTURE
AND INSTABILITY. THIS COULD LEAD TO A RELATIVELY ACTIVE WEATHER
PATTERN DOWN HERE WITH INCREASING CHANCES FOR SHOWERS AND
THUNDERSTORMS. THIS COULD BEGIN AS EARLY AS FRIDAY
AFTERNOON/EVENING. MODELS ARE SHOWING WEAK INSTABILITY NEAR THE
CASCADES THEN, SO THERE IS A SLIGHT CHANCE OF LATE
AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS THERE AND ALSO PERHAPS
AN ISOLATED SHOWER/T-STORM NEAR THE COAST RANGE MOUNTAINS.
MOISTURE AND FORCING GRADUALLY INCREASE THIS WEEKEND, AND PEAK
SUNDAY INTO MONDAY AS THE LOW EVENTUALLY MOVES ONSHORE INTO
CALIFORNIA TO OUR SOUTH. CURRENTLY, IT STILL LOOKS LIKE SUNDAY
AND MONDAY FEATURE THE MOST WIDESPREAD CHANCES, INCLUDING ALONG
THE COAST. TEMPERATURES WILL COOL DOWN BY MONDAY SINCE WE'LL
GENERALLY BE IN THE CLOUDIER, SHOWERY PATTERN. THE FOCUS FOR
SHOWER/T-STORM ACTIVITY SHIFTS TO EAST OF THE CASCADES ON TUESDAY
AS THE CUT OFF LOW GRADUALLY SHIFTS EASTWARD.
MODELS THEN SHOW UPPER RIDGING RETURNING TOWARD THE MIDDLE OF
NEXT WEEK WITH THE AIR MASS WARMING AGAIN. -SPILDE
AVIATION...28/06Z TAFS...SOME LOW CLOUDS AND PATCHY MVFR IS
POSSIBLE IN THE UMPQUA VALLEY AND ALONG THE COAST TONIGHT AND EARLY
WEDNESDAY. OTHERWISE, VFR CONDITIONS WILL PREVAIL ACROSS THE
FORECAST AREA FOR MOST OF WEDNESDAY.
-SMITH
MARINE...UPDATED 300 AM PDT WEDNESDAY, APRIL 29, 2026....A
THERMAL TROUGH PATTERN WILL BRING STRONG NORTH WINDS THROUGH
SATURDAY. NORTH WINDS WILL REACH PEAK STRENGTH DURING THURSDAY AND
FRIDAY AFTERNOONS. THE STRONGEST WINDS AND VERY STEEP SEAS ARE
EXPECTED SOUTH OF PORT ORFORD THIS AFTERNOON AND EVENING, AND ARE
LIKELY AGAIN THURSDAY AFTERNOON THROUGH AT LEAST FRIDAY EVENING.
MEANTIME, SEAS WILL BE STEEP ELSEWHERE. STEEP, FRESH SWELL MAY
LINGER WHILE WINDS DIMINISH AND TURN SOUTHERLY SATURDAY NIGHT INTO
SUNDAY.
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 8 PM PDT FRIDAY
FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT
THIS EVENING FOR PZZ356-376.
HAZARDOUS SEAS WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
EVENING FOR PZZ356-376.
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