134
FXUS66 KMFR 210109
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
609 PM PDT SUN SEP 20 2026
..UPDATED THE AVIATION SECTION
AVIATION...21/00Z TAFS
EARLY THIS EVENING, A MIX OF IFR/LIFR IS
PRESENT AT THE COAST NORTH OF PORT ORFORD, AND NEAR BROOKINGS. THIS
STRATUS WILL EXPAND INTO THE COQUILLE AND LOWER UMPQUA VALLEYS AFTER
06Z, THEN INTO THE CENTRAL PORTION OF THE UMPQUA VALLEY (INCLUDING
ROSEBURG)AFTER 10Z. CONDITIONS WILL BEGIN TO IMPROVE AFTER 15Z,
MAINLY INLAND. VFR IS EXPECTED AT ROSEBURG BY 18Z. BREAKS IN THE
STRATUS ARE EXPECTED AT THE COAST IN THE AFTERNOON, ALONG WITH
LIFTING TO MVFR AS A PREDOMINANT CONDITIONS. HOWEVER, CEILINGS WILL
MOSTLY PERSIST THROUGH THE DAY.
VFR WILL CONTINUE ELSEWHERE THROUGH MONDAY AFTERNOON. A FEW CUMULUS
BUILDUPS ARE EXPECTED IN THE AFTERNOON IN NORTHERN CALIFORNIA AND
EAST OF THE CASCADES, WITH A SHOWER OR ISOLATED THUNDERSTORM
POSSIBLE LATE IN THE DAY IN SOUTHEAST SISKIYOU COUNTY.
MARINE...UPDATED 230 PM PDT SUNDAY, SEPTEMBER 20, 2026
GUSTY
NORTH WINDS WILL MAINTAIN STEEP SEAS SOUTH OF CAPE BLANCO INTO
TONIGHT. WINDS AND SEAS WILL INCREASE FURTHER INTO MONDAY EVENING.
MODELS ARE AMBITIOUS WITH SOME HIGH AND VERY STEEP WIND WAVES AROUND
8 TO 9 FEET, WHICH SHOULD PUSH US INTO HAZARDOUS SEAS CRITERIA.
WINDS EASE SOME ON TUESDAY AND CONDITIONS SHOULD IMPROVE NORTH OF
CAPE BLANCO AS SEAS BECOME LESS STEEP AND TRANSITION TO SWELL
DOMINATED. STEEP TO VERY STEEP SEAS PERSIST SOUTH OF CAPE BLANCO
THROUGH TUESDAY, WITH CONDITIONS LIKELY IMPROVING FOR THE LATTER
HALF OF THE WEEK.
PREV DISCUSSION
/ISSUED 243 PM PDT SUN SEP 20 2026/
KEY MESSAGES...
* WARM AND DRY WEATHER CONTINUES.
* THERE IS A 40-60% CHANCE OF RAIN THURSDAY NIGHT INTO FRIDAY.
* TEMPERATURES TREND COOLER BY THE WEEKEND.
DISCUSSION...
COASTAL STRATUS AND SOME HIGHER CLOUDS ARE THE MAIN WEATHER
FEATURES THIS AFTERNOON AS HIGH PRESSURE REMAINS IN CONTROL.
TEMPERATURES ARE JUST A TAD WARMER THAN NORMAL AS WE'RE
FORECASTING A HIGH OF 91 HERE IN MEDFORD AND 85 IS THE NORMAL HIGH
AT MFR AROUND MID TO LATE SEPTEMBER.
OTHERWISE, MORE COASTAL CLOUDS AND FOG WILL COVER THE COAST
TONIGHT WITH A STRONG MARINE PUSH. TEMPERATURES WILL TREND
SLIGHTLY LOWER ON MONDAY AS THE 500 MB RIDGE WEAKENS A BIT. A
CLOSED LOW WILL ALSO MOVE INTO CENTRAL CALIFORNIA ON MONDAY
AFTERNOON. SOME UPPER LEVEL ENERGY WILL ROTATE INTO NORTHERN
CALIFORNIA FROM THE EAST BY MONDAY AFTERNOON. WE'LL PROBABLY SEE
SOME CUMULUS BUILD UPS AND THERE IS A VERY LOW CHANCE FOR A SHOWER
OR TWO.
HEADING INTO TUESDAY AND WEDNESDAY, WE'LL BE UNDER ZONAL FLOW
WITH A DEEP TROUGH IN THE GULF OF ALASKA. TEMPERATURES SHOULD
TREND SLIGHTLY LOWER INTO THE UPPER 70'S WITHIN VALLEYS WEST AND
EAST OF THE CASCADES. BY THURSDAY, THE EVOLUTION OF THE WEATHER
PATTERN BECOMES A LITTLE MORE UNCERTAIN.
ABOUT 30 TO 40% OF ENSEMBLE MEMBERS HAVE A WEAKER SURFACE LOW
SPINNING UP ALONG A BAROCLINIC ZONE IN THE PACIFIC. THAT LOW AND
UPPER LEVEL TROUGH WILL PROBABLY MOVE INTO THE PACIFIC NORTHWEST
AROUND THE THURSDAY TO FRIDAY TIME PERIOD. HOWEVER, ANOTHER 30 TO
40% OF ENSEMBLE MEMBERS KEEP THINGS QUITE DRY FROM THURSDAY INTO
FRIDAY. IT SEEMS LIKE THERE IS LESS AVAILABLE MOISTURE IN THIS
SET OF ENSEMBLE MEMBERS. THERE ARE ALSO QUESTIONS WHERE THE BULK
OF THE RAIN COULD FALL. SOME ENSEMBLE MEMBERS TARGET WASHINGTON
AND AREAS WELL TO OUR NORTH VERSUS SOUTHERN OREGON. IN ANY CASE,
STILL A LOT TO SORT OUT AROUND THURSDAY NIGHT INTO FRIDAY.
AFTER FRIDAY, CONDITIONS WILL DRY OUT WITH TEMPERATURES MOVING
NOTABLY COOLER WITH FALL LIKE TEMPERATURES.
-SMITH
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 PM PDT MONDAY
FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING FROM 2 PM TO 11 PM PDT MONDAY FOR PZZ356-
376.
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