917
FXUS66 KMFR 291147
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
447 AM PDT TUE SEP 29 2026
KEY MESSAGES
* WARM AND DRY WEATHER REMAINS IN THE FORECAST.
* MARINE STRATUS LOOKS TO DEVELOP TONIGHT, WITH THIS LAYER
POSSIBLY REACHING INTO THE UMPQUA VALLEY.
* THE WARMEST TEMPERATURES OF THE FORECAST PERIOD ARE EXPECTED ON
SATURDAY AND SUNDAY, REACHING ABOUT 10 DEGREES ABOVE SEASONAL
NORMS ACROSS THE AREA.
DISCUSSION
A STABLE ATMOSPHERIC PATTERN WILL BRING SEASONAL
TEMPERATURES AND DRY CONDITIONS ACROSS NORTHERN CALIFORNIA AND
SOUTHERN OREGON TODAY. FOR TODAY, THAT WILL BRING VALLEY
TEMPERATURES IN JACKSON, JOSEPHINE, AND SISKIYOU COUNTIES TO THE
HIGH 70S TO LOW 80S. COASTAL CITIES, THE UMPQUA VALLEY, AND EAST
SIDE VALLEYS AND BASINS LOOK TO BE IN THE MID 70S.
HIGH PRESSURE LOOKS TO SETTLE IN THE SOUTHWESTERN UNITED STATES IN
THE MIDDLE OF THE WEEK, BUILDING A RESILIENT RIDGE THAT WILL BRING
SLOWLY INCREASING TEMPERATURES THROUGH THE WEEK AND WEEKEND AHEAD.
ZONAL FLOW OVER THE TOP OF THE RIDGE WILL KEEP DAYTIME HIGHS ABOUT 5
DEGREES ABOVE NORMAL LEVELS FOR WEDNESDAY THROUGH FRIDAY. A SLIGHT
NORTHWEST ORIENTATION TO MID LEVEL FLOW COULD PUSH MARINE STRATUS
INTO THE UMPQUA VALLEY ON EARLY WEDNESDAY MORNING, BUT THIS WILL
HAVE LITTLE IMPACT ON THE DAY'S CONDITIONS.
GOING IN TO THE WEEKEND, CURRENT DETERMINISTIC IMAGERY SHOWS HIGH
PRESSURE PUSHING FARTHER NORTH AND OVER THE AREA. THIS LOOKS TO
NUDGE TEMPERATURES TO ABOUT 10 DEGREES OVER NORMAL LEVELS. THE
OREGON COAST HAS FORECAST HIGHS IN THE LOW TO MID 70S. THE UMPQUA
VALLEY LOOKS TO BE IN THE MID 80S WHILE OTHER WEST SIDE VALLEYS WILL
APPROACH OR EXCEED 90 DEGREES. TO THE EAST, VALLEYS AND BASINS COULD
SEE TEMPERATURES IN THE HIGH 70S TO MID 80S THROUGH THE WEEKEND.
THESE HIGHS COULD APPROACH RECORD LEVELS IN SOME AREAS, ESPECIALLY IN
AREAS IN OR NEAR NORTHERN CALIFORNIA.
LONG-TERM METEOGRAMS DO SHOW SOME DIVERGENCE BEYOND SUNDAY, WITH GFS
ENSEMBLE GUIDANCE SHOWING A STEADY COOLING TREND NEXT WEEK WHILE THE
ECMWF KEEPS WARM TEMPERATURES IN THE FORECAST. PRECIPITATION
EXPECTATIONS REMAIN SLIGHT BEYOND DAY 7, WITH ABOUT 10% OF ECMWF
MEMBERS EXPECTING SOME AMOUNT OF COASTAL PRECIPITATION WHILE THE GFS
KEEPS THINGS DRY INTO MID OCTOBER. -TAD
AVIATION...29/12Z TAFS
WHILE SATELLITE IMAGERY SHOWS SOME
DEVELOPMENT AROUND NORTH BEND EARLY THIS MORNING, SO FAR THESE
CLOUDS HAVE NOT SPREAD OVER THE TERMINAL. A SLIGHT CHANCE REMAINS,
BUT SUNRISE WOULD CLEAR ANYTHING THAT MANAGES TO DEVELOP. MARINE
STRATUS IS EXPECTED TO DEVELOP NORTH OF CAPE BLANCO THIS EVENING OR
EARLY TONIGHT AND BRING IFR/LIFR LEVELS, WITH GUIDANCE SUGGESTING
THAT STRATUS COULD REACH INTO THE UMPQUA VALLEY NEAR THE END OF THIS
TAF PERIOD AND BRING MVFR CEILINGS.
OTHER AREAS LOOK TO REMAIN AT VFR LEVELS THROUGH THE TAF PERIOD. -TAD
MARINE...UPDATED 400 AM PDT TUESDAY, SEPTEMBER 29, 2026
STEEP SEAS WILL CONTINUE SOUTH OF CAPE BLANCO AT LEAST THROUGH
WEDNESDAY EVENING, AND POSSIBLY THROUGH FRIDAY EVENING. WINDS AND
SEAS EASE SLIGHTLY OVERNIGHT INTO TUESDAY MORNING. BUT, WEST-
NORTHWEST SWELL WILL BUILD AND NORTH WINDS WILL INCREASE AGAIN SOUTH
OF CAPE BLANCO ON TUESDAY AFTERNOON. WIND SPEEDS WILL REACH A PEAK
ON WEDNESDAY EVENING.
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 PM PDT
WEDNESDAY FOR PZZ356-376.
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