257
FXUS66 KMFR 172118
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
218 PM PDT WED SEP 17 2025
DISCUSSION
TODAY HAS SOME OF THE WARMEST AFTERNOON TEMPERATURES
FOR AREAS EAST OF THE CASCADES AS THE THERMAL TROUGH CONTINUES
MOVING INLAND. TEMPERATURES ARE IN THE 70S AND 80S EAST TODAY. THE
WARMEST LOCATIONS WEST OF THE CASCADES WILL BE IN THE ROGUE
VALLEY. MEDFORD IS AT 84 DEGREES AS OF 1 PM, AND IS EXPECTED TO
WARM TO 90 LATER THIS AFTERNOON.
TROPICAL STORM MARIO IS LOOKING TO INTERACT WITH THE MAIN FLOW
TOMORROW AND CAUSE AN UPPER TROUGH TO THE NORTHWEST TO SLOW ITS
MOVEMENT EAST. THERE ARE STILL MODEL DISAGREEMENTS, EVEN IN THE
CAMS. THEREFORE, A 10-25% CHANCE FOR SHOWERS HAS BEEN ADDED FOR MORE
OF SISKIYOU AND MODOC COUNTIES TOMORROW NIGHT INTO FRIDAY. ON FRIDAY
THIS 15-25% CHANCE COULD EXPAND NORTHWARD TOWARDS THE
OREGON/CALIFORNIA BORDER. SISKIYOU AND MODOC COUNTIES AND SOUTHERN
KLAMATH AND LAKE COUNTIES WILL HAVE A 10-20% CHANCE FOR LIGHTNING
FRIDAY AS THE LOW MOVES CLOSER TO THE AREA.
THERE IS ALSO ONLY SOME AGREEMENT ON LOCATION FOR RAIN CHANCES
SATURDAY. WHILE MODELS ALIGN MORE FOR NORTHERN CALIFORNIA TO SEE
RAIN SATURDAY, MORE UNCERTAINTY LIES NEAR AND EAST OF THE CASCADES.
FOR NOW, THERE IS A 15-25% CHANCE FOR SHOWERS NEAR THE TRINITY HORN.
OTHER THAN THESE RAIN CHANCES, THINGS WILL REMAIN CONSTANT WITH NEAR
TO SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. THE NEXT
TIMEFRAME TO WATCH FOR WOULD BE INTO THE MIDDLE OF NEXT WEEK AS AN
UPPER TROUGH SWINGS DOWN INTO THE PNW. AS OF THIS AFTERNOON UPDATE,
WE ARE SHOWING THE MORE BULLISH MODELS THAT HAVE THE PRECIPITATION
COMING IN BY TUESDAY AFTERNOON.
AVIATION...17/18Z TAFS
LIFR CONDITIONS PERSIST ALONG THE COAST
SOUTH OF GOLD BEACH AND OVER THE MARINE WATERS WITH MVFR CEILINGS
JUST OFFSHORE NORTH OF CAPE BLANCO. CONDITIONS ARE IMPROVING ALONG
THE COAST, BUT THIS IMPROVEMENT WILL LIKELY ONLY LAST THROUGH THE
AFTERNOON WHEN GUSTY NORTH WINDS ARE AT THEIR STRONGEST. IFR/LIFR
CONDITIONS ARE EXPECTED TO RETURN TO THE COAST NORTH OF CAPE BLANCO
THIS EVENING AND PERSIST INTO THURSDAY MORNING.
VFR CONDITIONS WILL PREVAIL FOR INLAND LOCATIONS WITH TYPICAL
DIURNAL BREEZES TODAY. /BR-Y
MARINE...UPDATED 215 PM PDT WEDNESDAY, SEPTEMBER 17, 2025
TONIGHT, GUSTY NORTHERLY WINDS BUILD ACROSS AREA WATERS. STEEP TO
VERY STEEP SEAS ARE EXPECTED NORTH OF CAPE BLANCO, WITH POSSIBLE
GALE GUSTS SOUTH OF CAPE BLANCO. THESE CONDITIONS CONTINUE THROUGH
AT LEAST FRIDAY MORNING BUT COULD LINGER INTO THE EVENING HOURS.
FIRE WEATHER
UPDATED 200 PM PDT WEDNESDAY, SEPTEMBER 17,
2025...SEASONABLY HOT TEMPERATURES WITH LOW DAY TIME RHS (TEENS-20S)
WILL CONTINUE TODAY, BUT TEMPERATURES WILL TREND SOMEWHAT LOWER AND
RHS SOMEWHAT HIGHER WEST OF THE CASCADES THIS AFTERNOON. EAST OF THE
CASCADES, CONDITIONS TODAY WILL BE SIMILAR TO THOSE OF YESTERDAY.
ONSHORE FLOW HAS RETURNED SO EXPECT MORE TYPICAL DIURNAL BREEZES
TODAY INTO THURSDAY. THERE WILL BE ANOTHER ROUND OF NORTHEASTERLY
WINDS TONIGHT INTO THURSDAY MORNING, BUT RECOVERIES WILL CONTINUE
THE IMPROVING TREND COMPARED TO EARLY IN THE WEEK.
CONFIDENCE HASN'T REALLY IMPROVED MUCH REGARDING THUNDER POTENTIAL
FOR THURSDAY INTO FRIDAY. ANOTHER UPPER LEVEL TROUGH WILL APPROACH
THE REGION TODAY, BUT WILL STALL OFFSHORE IN RESPONSE TO THE
REMNANTS OF TROPICAL STORM MARIO MOVING NORTHWARD ALONG THE
CALIFORNIA COAST. THERE IS STILL UNCERTAINTY REGARDING HOW FAR NORTH
AND WEST THIS MOISTURE MAKES IT, AND THE HIGH RESOLUTION CONVECTION
MODELS SHOW QUITE THE SPREAD ON WHERE SHOWERS/THUNDERSTORMS ARE
POSSIBLE. THEY DO AGREE, HOWEVER, ON MOISTURE NOT ARRIVING UNTIL
THURSDAY NIGHT INTO FRIDAY AND MAINTAIN THE BEST CHANCES SOUTH OF
THE OR/CA BORDER, SO WE'VE INCLUDED THIS IN THE FORECAST UPDATE FOR
THIS AFTERNOON. THERE ARE SOME SOLUTIONS THAT BRING STORMS INTO
JACKSON/JOSEPHINE COUNTIES AND/OR SOUTHERN KLAMATH/LAKE COUNTIES
WHILE OTHERS KEEP THUNDERSTORMS CONFINED SOUTH OF THE OR/CA BORDER,
SO THERE COULD BE UPDATES TO THE FORECAST OVER THE COMING SHIFTS. AT
THIS POINT IT DOESN'T LOOK LIKE A BIG LIGHTNING EVENT, AND IN
COORDINATION WITH LOCAL FIRE AGENCIES, WILL MAINTAIN A HEADLINE FOR
THIS POTENTIAL IN THE FWF UNLESS THE COVERAGE OF LIGHTNING TRENDS
HIGHER OVER THE UPCOMING DAYS.
OVER THE WEEKEND, THE TROPICAL REMNANTS WILL GET SWEPT INTO THE
WESTERLIES ON SATURDAY AS ANOTHER TROUGH PASSES THROUGH THE REGION,
BUT THUNDER CHANCES COULD LINGER ACROSS EASTERN LAKE/MODOC COUNTIES
SATURDAY AFTERNOON. WE EXPECT PERIODS OF ENHANCED BREEZES THIS
WEEKEND AS A FEW DRY FRONTS MOVE THROUGH THE REGION, BUT WE DON'T
EXPECT ANY MEANINGFUL PRECIPITATION THIS WEEKEND...MAYBE SOME LIGHT
PRECIP ACROSS FAR NORTHERN AREAS ON SUNDAY. MEANWHILE A CUT OFF LOW
WILL LINGER OFFSHORE OF CALIFORNIA, FAR ENOUGH WEST THAT WE AREN'T
CONCERNED ABOUT A THUNDERSTORM PATTERN. THIS WILL COME INTO PLAY
AROUND MID-WEEK NEXT WEEK AS IT TOO, FINALLY GETS SWEPT UP INTO THE
MAIN FLOW AND POTENTIALLY BRINGS A MORE WIDESPREAD APPRECIABLE
WETTING RAINFALL IN THE SEPTEMBER 23RD-26TH TIMEFRAME. DETAILS AT
THIS TIME RANGE OF COURSE ARE UNCLEAR, BUT NUMEROUS MEMBERS IN THE
ENSEMBLE SUITE OF SOLUTIONS ARE PINPOINTING THIS TIMEFRAME AS WETTER
AND COOLER. STAY TUNED AS THE TIME DRAWS NEARER. /BR-Y
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS
EVENING FOR PZZ350-356-370-376.
GALE WARNING FROM 11 PM THIS EVENING TO 11 AM PDT FRIDAY FOR
PZZ356-376.
HAZARDOUS SEAS WARNING FROM 11 PM THIS EVENING TO 11 AM PDT
FRIDAY FOR PZZ370.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page