664
FXUS66 KMFR 092130
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
230 PM PDT SUN AUG 9 2026
KEY MESSAGES
* WARM TEMPERATURES CONTINUE BUT DECREASE DAY TO DAY UNTIL
SEASONABLE CONDITIONS ARE PRESENT IN THE MIDDLE OF THE WEEK.
* DRY WEATHER AND ELEVATED AFTERNOON BREEZES ARE BEHIND CONTINUING
FIRE WEATHER CONCERNS.
* PERIODS OF SMOKE ACCUMULATION ARE EXPECTED OVER KLAMATH, LAKE,
AND MODOC COUNTIES.
* THUNDERSTORM CHANCES REMAIN IN THE FORECAST, BUT APPEAR OVERALL
SLIGHT AT THIS MOMENT.
DISCUSSION
ZONAL FLOW WITH A SLIGHTLY SOUTHWEST ORIENTATION IS
PRESENT IN THE UPPER PATTERN, WHICH WILL BRING STEADILY DECREASING
TEMPERATURES UNTIL MOST AREAS SEE SEASONAL CONDITIONS BY THE MIDDLE
OF THE WEEK AHEAD. ATMOSPHERIC MOISTURE REMAINS LOW IN THIS PERIOD
OF THE FORECAST, WHICH WILL KEEP INLAND SKIES GENERALLY CLEAR.
ONSHORE FLOW WILL KEEP A PATTERN OF MARINE STRATUS BUILDUP AND
EROSION ALONG THE COAST, WHICH MAY KEEP DAYTIME TEMPERATURES COOLER
THAN EXPECTED IN AREAS WHERE CLOUD LAYERS ENDURE INTO THE AFTERNOON.
WHILE THERE ARE NO FEATURES THAT LOOK TO CAUSE GUSTY INLAND WINDS, A
SERIES OF WEAK DISTURBANCES FOLLOWING THE UPPER FLOW WILL HELP TO
KEEP AFTERNOON BREEZES SLIGHT ELEVATED. THIS COMBINATION OF DRY
CONDITIONS AND ELEVATED BREEZES WILL KEEP FIRE WEATHER CONCERNS
ELEVATED FOR THE TIME BEING.
IN SPITE OF THOSE ELEVATED BREEZES, SMOKE REMAINS TRAPPED IN SOME
LOW-LYING AREAS. WITH WESTERLY OR SOUTHWESTERLY FLOW ALOFT AND
CURRENTLY DECREASED FIRE ACTIVITY, ADDITIONAL SMOKE REACHING WEST
SIDE VALLEYS IS NOT EXPECTED. CALM OVERNIGHT CONDITIONS LOOK TO
ALLOW FOR PERIODS OF SMOKE ACCUMULATION OVER KLAMATH, LAKE, AND
MODOC COUNTIES.
A SOMEWHAT INTRICATE UPPER PATTERN DEVELOPS TOWARDS THE END OF THE
WEEK, WITH A CUTOFF LOW DROPPING TO THE SOUTH AND BUILDING A TROUGH
NEAR THE PACIFIC COAST. THIS PATTERN MAY BRING SOME MONSOONAL
MOISTURE AS WELL AS PERIODS OF INSTABILITY WHICH MAKES THUNDERSTORMS
A CONCERN, BUT AGREEMENT ON IF, WHERE, AND WHEN ACTIVITY DEVELOPS IN
THE CWA IS SPARSE. DETERMINISTIC IMAGERY FOR THURSDAY THROUGH THE
WEEKEND SHOWS THE MAIN MOISTURE PLUME SHIFTED EASTWARD COMPARED TO
MODEL DATA FROM 24 HOURS AGO. THUNDERSTORM TRIGGERS ARE ALSO
SOMEWHAT LACKING AT THE MOMENT, LEADING TO GENERALLY ISOLATED
AFTERNOON AND EVENTING THUNDERSTORMS EAST OF THE CASCADES IN MODEL
IMAGERY. BUT CONFIDENCE IN ANY SPECIFIC OUTCOME REMAINS SLIGHT,
AS ANY CHANGE TO THE EXPECTED CONDITIONS COULD RESULT IN MORE
ACTIVITY OR THE COMPLETE ABSENCE OF ANY THUNDERSTORM DEVELOPMENT
THROUGH THE WEEKEND. -TAD
AVIATION...09/18Z TAFS
WILDFIRE SMOKE AT KLAMATH FALLS WILL BRING
VISIBILITY REDUCTIONS IN HAZE AND EVEN SOME HIGHER CEILINGS FROM THE
AIRPORT EASTWARD INTO EARLY THIS AFTERNOON, BUT NW WINDS SHOULD
BRING VFR AGAIN BY AROUND 21-22Z. ONCE THE SUN SETS, THE INVERSION
SHOULD REDEVELOP AND SMOKE WILL SETTLE BACK IN OVER THE AIRPORT
LATER THIS EVENING WITH POTENTIAL FOR MVFR CEILINGS/VISIBILITY
AGAIN.
MARINE STRATUS HAS CLEARED TO VFR AT ALL BUT THE IMMEDIATE SOUTH
COAST LATE THIS MORNING. EVEN THERE, WE EXPECT ENOUGH NE WIND
COMPONENT TO CLEAR THINGS OUT FOR A WHILE THIS AFTERNOON. STRONG,
GUSTY NORTH WINDS UP TO 30 KT WILL OCCUR AT NORTH BEND THIS
AFTERNOON/EVENING. EXPECT THE MARINE LAYER TO RETURN THIS EVENING
WITH MORE IFR STRATUS/FOG DURING THE OVERNIGHT INTO MONDAY MORNING.
MEDFORD AND ROSEBURG WILL BE VFR FOR THE NEXT 24 HOURS WITH JUST
SOME LOCALLY BREEZY WINDS THIS AFTERNOON/EVENING (GUSTS TO 20 KT).
-SPILDE
MARINE...UPDATED 230 PM PDT SUNDAY, AUGUST 9, 2026
GUSTY NORTH
WINDS CONTINUE OVER AREA WATERS, WITH AREAS OF GALE FORCE GUSTS
AND VERY STEEP SEAS SOUTH OF PORT ORFORD. ELSEWHERE, GUSTY WINDS
AND STEEP SEAS ARE EXPECTED. THESE CONDITIONS ARE EXPECTED TO
CONTINUE THROUGH WEDNESDAY EVENING. WINDS LOOK TO EASE ON THURSDAY
BUT UNSETTLED SEAS COULD CONTINUE INTO NEXT WEEKEND. -TAD
FIRE WEATHER...UPDATED 200 PM PDT SUNDAY, AUGUST 9, 2026
WE'LL
STAY IN A PATTERN OF VERY WARM, VERY DRY, AND OCCASIONALLY BREEZY
CONDITIONS TODAY THROUGH MID WEEK. THIS PATTERN INCLUDES OVERNIGHT
BREEZY EAST TO NORTHEAST WINDS AT RIDGE TOPS OF SW OREGON AND NW
CALIFORNIA (MOST NOTABLY THE COAST RANGE AND KALMIOPSIS WILDERNESS)
ALONG WITH POOR TO MODERATE RH RECOVERY. A CHANNELING OF WINDS DOWN
THE CHETCO COULD RESULT IN SOME DRIER/WARMER CONDITIONS ALONG THE SW
OREGON COAST AS WELL.
UPPER LEVEL RIDGING SHIFTING BACK TOWARD THE FOUR CORNERS WILL ALLOW
WESTERLY ZONAL FLOW ALOFT TO BRING LOWER HEIGHTS AND MODEST COOLING
TO INLAND AREAS. GENERALLY, THE TREND WILL BE TO LOWER DAYTIME MAXTS
DOWN BY A DEGREE OR TWO EACH DAY, AND THIS SHOULD SUBSEQUENTLY ALLOW
DAYTIME MINRHS TO BE SLIGHTLY HIGHER. EVEN SO, IT'LL BE DRY AND
UNSTABLE, SO ANY FIRES ON THE LANDSCAPE WILL STILL HAVE THE ABILITY
TO GROW SIGNIFICANTLY, ESPECIALLY DURING THE PEAK BURNING PERIODS
DURING THE AFTERNOONS/EVENINGS. OVERNIGHT RH RECOVERIES HAVEN'T BEEN
GOOD THE LAST COUPLE OF NIGHTS, GENERALLY ONLY IN THE 20-35% RANGE
FOR SOME OF THE UPPER SLOPES AND RIDGES. THERE SHOULD BE SLIGHT
NIGHTLY IMPROVEMENT IN RECOVERIES FROM NW TO SE THROUGH THE PERIOD.
THINGS TREND TOWARD NORMAL FOR MID NEXT WEEK, BUT TEMPERATURES STILL
PROBABLY REMAIN A FEW DEGREES ABOVE NORMAL FOR MOST LOCATIONS.
MODELS AND ENSEMBLE GUIDANCE CONTINUE TO SHOW A WEAKNESS OR UPPER
TROUGH DEVELOPING NEAR OR JUST OFF THE CALIFORNIA COAST WED/THU AND
ALSO SHOW AN INCREASE IN MONSOONAL MOISTURE COMING UP FROM THE SOUTH
LATE WEEK. RIGHT NOW, MODELS HAVE LESSENED THE RISK A BIT, BUT STILL
BRING ISOLATED LIGHTNING CHANCES UP INTO NORCAL AROUND THURSDAY WITH
THE BEST CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS FRI/SAT FROM
NORCAL UP THE CASCADES AND OVER TO THE EAST SIDE. BUT, GIVEN PLENTY
OF UNCERTAINTY IN STRENGTH OF FORCING MECHANISMS AND OVERALL
INSTABILITY, CONFIDENCE HAS NOTCHED DOWNWARD A BIT IN THIS FORECAST
CYCLE. KEEP CHECKING BACK FOR UPDATES SINCE ANY LIGHTNING BRINGS
WITH IT THE RISK OF NEW FIRE STARTS. -SPILDE
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...GALE WARNING UNTIL 11 PM PDT WEDNESDAY FOR
PZZ356-376.
SMALL CRAFT ADVISORY UNTIL 11 PM PDT WEDNESDAY FOR PZZ350-356-
370-376.
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