986
FXUS66 KMFR 262158
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
258 PM PDT WED AUG 26 2026
KEY MESSAGES
* HEIGHTENED FIRE WEATHER CONCERNS ACROSS THE EAST SIDE THROUGH
THURSDAY EVENING DUE TO GUSTY WINDS AND LOW RH.
* WEAK INSTABILITY JUST CLIPPING FAR SOUTHEAST PORTIONS OF MODOC
AND LAKE COUNTIES FOR A SLIGHT CHANCE OF THUNDERSTORMS LATE
IN THE DAY ON FRIDAY.
* TEMPERATURES TREND COOLER INTO SATURDAY, AND REMAIN NEAR OR
BELOW NORMAL FOR THE NEXT WEEK.
* WEATHER PATTERN LARGELY INFLUENCED BY UPPER LEVEL TROUGHING,
RESULTING IN GUSTY WINDS IN THE AFTERNOONS/EVENINGS, AND NIGHT
AND MORNING COASTAL STRATUS EXTENDING INTO THE UMPQUA VALLEY FOR
THE EARLY MORNING HOURS.
* STRONG TROUGHING TUESDAY THROUGH THURSDAY NEXT WEEK FOR COASTAL
RAIN CHANCES, WITH THE HIGHEST PROBABILITY NORTH OF OUR AREA.
DISCUSSION
MODEL AGREEMENT/CONFIDENCE IN THE FORECAST IS HIGH
THROUGH MONDAY. A TROUGH WILL BE CENTERED NEAR THE BORDER WITH
CANADA THROUGH SATURDAY, THEN AFTER BRIEF RIDGING/SLIGHT WARMING
AND DRYING ON SUNDAY, A STRONGER TROUGH WILL QUICKLY FOLLOW A
SIMILAR TRACK SOUTHEASTWARD FROM ALASKA BEGINNING MONDAY. THE
EXACT TRACK AND STRENGTH OF THAT TROUGH IS IN QUESTION, BUT IT IS
LIKELY TO BE THE MAIN DRIVER OF OUR WEATHER CONDITIONS DURING NEXT
WEEK.
OVER THESE NEXT SEVERAL DAYS, THE COOLING TREND AND GUSTY, BREEZY
AFTERNOON AND EVENING WINDS WILL CONTINUE. THIS WILL CONTINUE TO
BRING HEIGHTENED FIRE WEATHER CONCERNS, PEAKING DURING THE
AFTERNOON/EVENING, PARTICULARLY ON THURSDAY, WITH STRONGER WINDS
AND RHS REMAINING FAIRLY LOW. FIRE WEATHER CONCERNS DIMINISH SOME
FRIDAY ONWARD AS RHS TREND HIGHER, BUT WITH AFTERNOONS REMAINING
BREEZY, AND NO PRECIPITATION EXPECTED (AT LEAST INTO TUESDAY),
FIRE DANGER REMAINS VERY HIGH ACROSS THE REGION.
THE ONLY EXCEPTION TO A STABLE AIR MASS, WITH DRY MID-LEVELS WILL
BE SOME TROPICAL MOISTURE BEING SWEPT INTO THE WESTERLIES ON
FRIDAY. GUIDANCE BRINGS THIS MOISTURE INTO CENTRAL CA/NORTHWESTERN
NEVADA, THEN JUST CLIPPING THE FAR SOUTHEASTERN PORTIONS OF
LAKE AND MODOC COUNTIES.
THE OUTLOOK IS FOR THE STRONGER TROUGH TO BRING AT LEAST SLIGHT
RAIN CHANCES TO AT LEAST THE COAST AND DOUGLAS COUNTY, AND
NORTHWARD AS EARLY AS TUESDAY, WITH A FOCUS FROM TUESDAY NIGHT
THROUGH WEDNESDAY NIGHT.
AVIATION...26/18Z TAFS
MARINE LAYER STRATUS IS ERODING, BUT WILL
MAINTAIN PATCHY MVFR CEILINGS ALONG THE COAST NORTH OF CAPE BLANCO
AND INTO THE COQUILLE AND LOWER UMPQUA VALLEYS INTO THE EARLY
AFTERNOON. THIS IMPROVEMENT WILL BE BRIEF. A WEAK FRONT WILL BRING A
MORE EXTENSIVE PUSH OF MVFR MARINE STRATUS AFTER 22Z, BOTH EXTENDING
INTO THE COASTAL VALLEYS AND LOWERING TO IFR AT THE COAST EARLY IN
THE EVENING WITH ABOUT A 10% PROBABILITY OF VERY LIGHT SHOWERS AT
THE COAST. THE STRATUS SURGE WILL CONTINUE INTO THE UMPQUA VALLEY
AFTER 05Z, WITH MVFR EXPECTED AT ROSEBURG/KRBG AFTER 10Z, THEN
LINGERING THROUGH THURSDAY MORNING.
ELSEWHERE, VFR CONDITIONS WILL PREVAIL WITH TYPICAL SUMMER TIME
DIURNAL BREEZES, INCREASING HIGH CLOUDS, AND THE POTENTIAL FOR A FEW
PATCHES OF STRATUS TO EXTEND OVER THE UMPQUA DIVIDE INTO JOSEPHINE
COUNTY/GRANTS PASS EARLY THURSDAY MORNING.
MARINE...UPDATED 200 PM PDT WEDNESDAY, AUGUST 26, 2026
RELATIVELY
CALM CONDITIONS WITH LIGHT WINDS AND LOW SEAS ARE EXPECTED INTO
FRIDAY MORNING. SOUTHERLY WINDS WILL PERSIST TODAY, THEN TURN
NORTHERLY ON THURSDAY. NORTH WINDS INCREASE ON FRIDAY WITH STEEP
SEAS EXPECTED SOUTH OF PORT ORFORD AND WITHIN 30 NM OF SHORE. WINDS
THEN STRENGTHEN FURTHER DURING THE WEEKEND, WITH STEEP SEAS LIKELY
SOUTH OF CAPE BLANCO. WINDS WILL BE STRONGEST DURING THE AFTERNOON
AND EVENING HOURS. CONDITIONS ARE LIKELY TO IMPROVE MONDAY INTO
TUESDAY.
FIRE WEATHER...UPDATED 200 PM PDT WEDNESDAY, AUGUST 26, 2026
CRITICAL FIRE WEATHER CONDITIONS ARE ANTICIPATED EAST OF THE
CASCADES THIS AFTERNOON AND EARLY EVENING AS AN UPPER LEVEL LOW
REMAINS OFF THE WASHINGTON COASTLINE. THIS LOW WILL MOVE EASTWARDS
BY THURSDAY WITH A DRY COLD FRONT MOVING INTO THE OREGON COAST
THURSDAY AFTERNOON. WINDS WILL TREND SLIGHTLY HIGHER WHILE
HUMIDITIES REMAIN VERY LOW AND PERHAPS HIT THE SINGLE DIGITS IN SOME
AREAS. CRITICAL FIRE WEATHER CONDITIONS ARE LIKELY IN MODOC COUNTY
AND MOST OF SOUTHERN LAKE AND KLAMATH COUNTIES THURSDAY. LASTLY, THE
HOT DRY WINDY INDEX HAS SOME CONFIDENCE(~40%) THAT LOCATIONS WILL
EXCEED THE 95TH PERCENTILE FOR LATE AUGUST. OVERALL, PRETTY
CONFIDENT IN A RED FLAG OCCURING IN SOUTHERN LAKE AND KLAMATH
COUNTIES IN ADDITION TO MODOC COUNTY THURSDAY.
BY FRIDAY, SOME TROPICAL MOISTURE WILL HIT CENTRAL CALIFORNIA. THE
LATEST FORECAST IS JUST CLIPPING OUR REGION IN MODOC COUNTY AND
SOUTHERN LAKE COUNTY. THIS HAS RESULTED IN A LOW CHANCE OF SHOWERS
OR THUNDERSTORMS IN THE WARNER MOUNTAINS FRIDAY AFTERNOON. IF STORMS
DO FORM, IT LOOKS LIKE THEY'LL BE MOVING FAST. HOWEVER, THIS
SCENARIO DOESN'T REALLY FIT OUR IDEAL LIGHTNING IGNITION EVENT AS WE
WOULD LIKE TO SEE MORE INSTABILITY.
HEADING INTO SATURDAY, ANOTHER UPPER TROUGH WILL SWING INTO THE
PACIFIC NORTHWEST. WE'RE EXPECTING HUMIDITIES TO BE HIGHER WHILE
WIND GUSTS ARE JUST NOT AS STRONG OVER OUR FORECAST AREA. WHILE FIRE
WEATHER CONDITIONS ARE NOT GREAT, IT DOESN'T APPEAR WE'LL REACH
CRITICAL WIND AND HUMIDITY IN OUR AREA SATURDAY.
THE LAST THING WE WANTED TO NOTE WAS THE IMPROVING RECOVERIES
THURSDAY NIGHT WITH VERY GOOD RECOVERIES FRIDAY NIGHT. SOME OF THIS
IS DUE TO DEEPER WESTERLY FLOW ACROSS THE REGION. HOWEVER, THE
TROPICAL MOISTURE ARRIVING FRIDAY APPEARS TO HELP THINGS
SIGNIFICANTLY FRIDAY NIGHT AS SOME LOCATIONS RECOVER TO 90% IN THE
VALLEYS OF KLAMATH COUNTY.
OVERALL, THURSDAY IS THE DAY OF HIGHEST CONCERN WITH THE FIRE
WEATHER THREATS DECREASING INTO THE WEEKEND.
-SMITH
MFR WATCHES/WARNINGS/ADVISORIES
OR...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR ORZ624-625.
CA...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR CAZ285.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FROM 2 PM TO 11 PM PDT
FRIDAY FOR PZZ356-376.
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