881
FXUS66 KMFR 261137
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
437 AM PDT WED AUG 26 2026
UPDATED AVIATION DISCUSSION
AVIATION...26/12Z TAFS
MARINE LAYER STRATUS WILL MAINTAIN
WIDESPREAD MVFR CEILINGS ALONG THE COAST NORTH OF CAPE BLANCO AND
INTO THE COQUILLE BASIN. MVFR CEILINGS ARE MORE PATCHY SOUTH OF CAPE
BLANCO AND MORE PERSISTENT FROM BROOKINGS SOUTHWARD. MVFR CEILINGS
ARE EXPECTED IN THE UMPQUA BASIN AROUND SUNRISE. THE MARINE LAYER
WILL PEEL BACK TO THE COAST AGAIN LATER THIS MORNING, BUT MVFR
CEILINGS ARE LIKELY TO PERSIST ALONG THE IMMEDIATE COAST THROUGH THE
AFTERNOON. ELSEWHERE, FOR INLAND TAF SITES, OTHER THAN HIGH CLOUDS,
VFR CONDITIONS WILL PREVAIL WITH TYPICAL SUMMER TIME DIURNAL
BREEZES.
PREV DISCUSSION
/ISSUED 254 AM PDT WED AUG 26 2026/
KEY MESSAGES...
* TEMPERATURES TREND COOLER TODAY, TRENDING COOLER THROUGH THE WEEK
INTO THE WEEKEND.
* WEATHER PATTERN LARGELY INFLUENCED BY UPPER LEVEL TROUGHING,
RESULTING IN GUSTY WINDS IN THE AFTERNOONS/EVENINGS.
* HEIGHTENED FIRE WEATHER CONCERNS ACROSS THE EAST SIDE THROUGH
THURSDAY DUE TO GUSTY WINDS AND LOW RH.
DISCUSSION...SOUTHWEST FLOW PERSISTS OVER THE REGION TODAY WITH
PERSISTENT HIGH PRESSURE OVER THE THE DESERT SOUTHWEST AND LOW
PRESSURE OFFSHORE. THIS LOW PRESSURE WILL GRADUALLY MOVE INLAND
INTO THE PACIFIC NORTHWEST OVER THE REMAINDER OF THE WEEK...A
PATTERN QUITE SIMILAR TO THAT OF LAST WEEK. WITH THIS TROUGH,
TEMPERATURES WILL GRADUALLY TREND COOLER OVER THE REMAINDER OF THE
WEEK, EVENTUALLY SETTLING INTO THE 80S AREA WIDE (EXCEPT FOR THE
COAST) FOR THE WEEKEND BEHIND THE TROUGH PASSAGE. PERSISTENT
ONSHORE FLOW WILL BRING THE NIGHTLY RETURN OF MARINE LAYER
INTRUSIONS ALONG THE COAST, AND EVENTUALLY INTO THE UMPQUA BASIN
THURSDAY MORNING. EXPECT PERIODS OF INCREASED MID AND HIGH LEVEL
CLOUD COVER AS SHORTWAVES PASS THROUGH IN SOUTHWEST FLOW AHEAD OF
THIS TROUGH.
ASIDE FROM THE COOLER TEMPERATURES, THE MAIN CONCERN WITH THIS
TROUGH WILL BE INCREASED AFTERNOON WINDS EACH DAY THROUGH THURSDAY.
THIS WILL BRING HEIGHTENED FIRE WEATHER CONCERNS EACH
AFTERNOON/EVENING AS DAILY WINDS INCREASE AND RHS REMAIN FAIRLY LOW.
FIRE WEATHER CONCERNS DIMINISH SOME FRIDAY ONWARD AS RHS TREND
HIGHER, BUT WITH NO PRECIPITATION EXPECTED ANYTIME SOON, FIRE DANGER
REMAINS VERY HIGH ACROSS THE REGION. PLEASE REMEMBER TO DO YOUR PART
AND PREVENT A SPARK. ONE LESS SPARK, ONE LESS FIRE.
THE MID-LEVELS WILL BE TOO DRY TO SUPPORT ANY THUNDERSTORM
DEVELOPMENT THIS WEEK, AND WHILE NO WIDESPREAD PRECIPITATION IS NOT
EXPECTED THROUGH THE FORECAST PERIOD, SOME OF THE GUIDANCE IS
SHOWING SOME TROPICAL MOISTURE BEING SWEPT INTO THE WESTERLIES ON
FRIDAY. CURRENT GUIDANCE BRINGS THIS MOISTURE INTO CENTRAL
CA/NORTHWESTERN NEVADA, WHICH COULD CLIP THE SOUTHEASTERN PORTIONS
OF THE FORECAST AREA OR REMAIN JUST SOUTH, DEPENDING ON HOW IT
INTERACTS WITH THE TROUGH PASSING INLAND AT THE SAME TIME. OVERALL,
THE THUNDERSTORM THREAT IS MINIMAL, BUT IT'S SOMETHING WORTH
WATCHING THIS WEEK.
BROAD TROUGHING WILL REMAIN OVER THE WESTERN CONUS OVER THE WEEKEND
AND INTO EARLY NEXT WEEK. DRY CONDITIONS LIKELY CONTINUE FOR MOST
AREAS WITH TEMPERATURES NEAR TO A FEW DEGREES BELOW NORMAL. THERE
ARE SOME INDICATIONS IN THE EXTENDED GUIDANCE FOR THE POTENTIAL FOR
A MORE WET FRONT TO MOVE ONSHORE AT SOME POINT NEXT WEEK (MID-LATTER
HALF). IT CERTAINLY DOESN'T LOOK LIKE A WIDESPREAD PRECIPITATION
SCENARIO, BUT MORE OF A WEAKENING FRONT AS IT MOVES ONSHORE
SCENARIO. THIS SCENARIO FOCUSES THE HIGHEST CHANCES FOR
PRECIPITATION (ONLY LIGHT AMOUNTS AT THAT) ALONG THE COAST, INTO THE
UMPQUA BASIN AND AREAS NORTHWARD. OF THE 00Z/26 ENSEMBLE SOLUTIONS,
ABOUT 50% SHOW SOME AMOUNT OF PRECIP ALONG THE COAST AND IN THE
UMPQUA BASIN, WITH ABOUT 15-25% SHOWING LIGHTER AMOUNTS FARTHER
INLAND (MEDFORD, KLAMATH FALLS, MT SHASTA CITY). THE GEFS SUITE IS
MORE BULLISH WITH INLAND/SOUTHWARD EXTENT COMPARED TO THE EC SUITE.
IT'S STILL EARLY IN THE FORECAST PERIOD TO HAVE ANY CONFIDENCE IN
THIS COMING TO FRUITION, AND OFTEN TIMES, WE SEE THESE PRECIP
CHANCES LOWER AS THE TIME GETS CLOSER, OR GET PUSHED LATER IN TIME
OVER FUTURE MODEL RUNS. CONFIDENCE IS HIGHER FOR CONTINUED COOLER
TEMPERATURES THROUGH NEXT WEEK, BUT WE'LL JUST HAVE TO WAIT AND SEE
HOW PRECIPITATION CHANCES TREND.
MARINE...UPDATED 130 AM PDT WEDNESDAY, AUGUST 26, 2026...RELATIVELY
CALM CONDITIONS WITH LIGHT WINDS AND LOW SEAS ARE EXPECTED THROUGH
THE WEEK. SOUTHERLY WINDS WILL PERSIST TODAY, THEN TURN NORTHERLY ON
THURSDAY. NORTH WINDS INCREASE ON FRIDAY SOUTH OF CAPE BLANCO, BUT
WIND DRIVEN SEAS LIKELY HOLD OFF UNTIL THE WEEKEND.
FIRE WEATHER...UPDATED 200 AM PDT WEDNESDAY, AUGUST 25, 2026...
SOUTHWEST FLOW WILL PERSIST OVER THE REGION THROUGH MUCH OF THE
WEEK. THE UPPER LEVEL PATTERN WILL LARGELY BE DOMINATED BY AN UPPER
LEVEL TROUGH OVER THE EASTERN PACIFIC THAT WILL MOVE INLAND INTO THE
PACIFIC NORTHWEST. THIS PATTERN IS QUITE SIMILAR TO THAT OF LAST
WEEK, WHEN GUSTY WINDS COMBINED WITH LOW DAYTIME RHS AND BROUGHT
CRITICAL FIRE WEATHER CONDITIONS. THIS WILL AGAIN BE POSSIBLE
THROUGH THURSDAY, POTENTIALLY FRIDAY AS WELL, AS THIS TROUGH BRINGS
GUSTY WINDS IN THE AFTERNOONS/EVENINGS. WITH LOW DAYTIME RHS
EXPECTED, NEAR CRITICAL CONDITIONS ARE POSSIBLE EACH DAY, WITH
CRITICAL CONDITIONS ALSO POSSIBLE IN THE SHASTA VALLEY AND PORTIONS
OF THE EAST SIDE.
RHS WILL TREND LOWER ACROSS THE EAST SIDE TODAY AND THURSDAY WHILE
WINDS WILL TREND A BIT STRONGER AS A DRY FRONT GRADUALLY MOVES
INLAND. THESE TWO DAYS SEEM MOST LIKELY FOR GUSTY WINDS/LOW RH TO
OVERLAP AND RESULT IN CRITICAL CONDITIONS FOR PORTIONS OF THE EAST
SIDE. A RED FLAG WARNING IS IN EFFECT FOR THIS AFTERNOON AND A FIRE
WEATHER WATCH IS IN PLACE FOR THURSDAY AFTERNOON, BOTH FOR FIRE
WEATHER ZONES (FWZS) 285 AND SOUTHERN 624/625. GUSTY WINDS WILL
CONTINUE ON FRIDAY (MAYBE JUST A BIT WEAKER THOUGHT), BUT RHS TREND
UPWARD WHICH COULD LIMIT THE CONCERN FOR CRITICAL FIRE WEATHER
CONDITIONS ON FRIDAY. ANOTHER DRY FRONT/UPPER LEVEL TROUGH PASSES
THROUGH THE REGION ON SATURDAY, BRINGING ANOTHER ROUND OF GUSTY
WINDS, THOUGH GENERALLY WEAKER COMPARED TO THIS WEEK. ALSO, RHS
LIKELY REMAIN ELEVATED ENOUGH THROUGH THE WEEKEND TO LOWER THE
CONCERN FOR CRITICAL FIRE WEATHER CONDITIONS.
MEANWHILE, ONSHORE FLOW WILL GENERALLY MAINTAIN MODERATE TO GOOD
RECOVERIES WITH NIGHTLY MARINE PUSHES FOR COASTAL ZONES. THE
EXCEPTION TO THIS COULD BE THURSDAY MORNING WHEN POOR RECOVERIES ARE
POSSIBLE ALONG THE WARNERS AND SOUTHERN PORTIONS OF THE FREMONT-
WINEMA NATIONAL FOREST. THUNDERSTORMS REMAIN OUT OF THE FORECAST.
GUIDANCE MAINTAINS AN AREA OF INCREASED MOISTURE MOVING INTO CENTRAL
CA/NORTHWEST NV, WHICH COULD BRING SOME PRECIPITATION TO THE
SOUTHEASTERN CORNERS OF MODOC/LAKE COUNTIES ON FRIDAY. INSTABILITY
ISN'T ALL THAT IMPRESSIVE FOR OUR ZONES AT THIS TIME, BUT CAN'T RULE
OUT AN ISOLATED THUNDERSTORM ON FRIDAY FOR THOSE AREAS.
MFR WATCHES/WARNINGS/ADVISORIES
OR...RED FLAG WARNING FROM 11 AM THIS MORNING TO 8 PM PDT THIS
EVENING FOR ORZ624-625.
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
EVENING FOR ORZ624-625.
CA...RED FLAG WARNING FROM 11 AM THIS MORNING TO 8 PM PDT THIS
EVENING FOR CAZ285.
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
EVENING FOR CAZ285.
PACIFIC COASTAL WATERS...NONE.
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