564  
FXUS66 KMFR 261304  
AFDMFR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MEDFORD OR  
604 AM PDT SUN APR 26 2026  
   
..UPDATED AVIATION DISCUSSION FOR 12Z TAFS  
 
   
DISCUSSION  
UNSTABLE AIR ALOFT REMAINS THE GUIDING FACTOR FOR  
TODAY'S FORECAST, ALTHOUGH LITTLE IMPACTFUL WEATHER IS EXPECTED.  
DAYTIME HIGHS ACROSS THE CWA LOOK TO BE AT OR JUST BELOW SEASONAL  
VALUES. SLIGHT SHOWER CHANCES (10-20%) DEVELOP ACROSS NORTHERN  
CALIFORNIA AND AREAS EAST OF THE CASCADES THIS AFTERNOON AND  
EVENING. WITH MODELED CAPE VALUES STAYING BELOW 200 J/KG AND A LACK  
OF ABUNDANT ATMOSPHERIC MOISTURE, THUNDERSTORM CHANCES OVER LAKE AND  
KLAMATH COUNTIES ARE NUDGED UP SLIGHTLY BUT REMAIN BELOW 10%. A BAND  
OF 10-20% THUNDERSTORM CHANCES REMAINS ALONG THE SOUTHERN BORDERS OF  
SISKIYOU AND MODOC COUNTIES. SPC ENSEMBLE "PAINTBALL" GUIDANCE,  
WHERE MODELED CELLS OF OVER 40 DBZ ARE SHOWN, HAS DECENT AGREEMENT  
ON ISOLATED TO SCATTERED ACTIVITY ALONG THAT SOUTHERN BORDER WITH  
MORE ISOLATED ACTIVITY ALONG THE LAKE/KLAMATH BORDER. A FEW STRAY  
SHOWERS MAY ALSO DEVELOP OVER EASTERN DOUGLAS COUNTY OR THE  
CASCADES BEFORE ACTIVITY DECREASES INTO THE EVENING HOURS.  
 
THIS UPPER INSTABILITY STARTS TO DRIFT AWAY TO THE EAST TO START THE  
WEEK AHEAD, ALTHOUGH A FEW LOCALIZED SHOWERS ARE POSSIBLE ON MONDAY.  
SEASONAL DAYTIME HIGHS MAY REMAIN THROUGH MONDAY AND TUESDAY BEFORE  
TEMPERATURES WARM ON WEDNESDAY INTO THE END OF THE WEEK. ON  
THURSDAY, NBM PROBABILISTIC GUIDANCE HAS A 50% CHANCE FOR MEDFORD TO  
EXCEED 80 DEGREES. THAT CHANCE DROPS TO 30% ON FRIDAY. OTHER AREAS  
ARE FORECAST TO SEE DAYTIME HIGHS 5 TO 10 DEGREES ABOVE NORMAL  
IN THE MIDDLE AND END OF THE WEEK AS WELL.  
 
THERE'S SOME UNCERTAINTY IN THESE DAYTIME HIGHS, AS DETERMINISTIC  
IMAGERY SHOWS A NUMBER OF SHORTWAVE FEATURES AND SMALL CUTOFF LOWS  
MOVING ALONG THE UPPER FLOW. THESE FEATURES CAN HAVE SOME IMPACT ON  
THE FORECAST, AS THEY CAN HELP KEEP THE UPPER RIDGE FROM BECOMING  
TOO RESILIENT. INDEED, THE SAME NBM PROBABILISTIC GUIDANCE INCLUDES  
A ~40% CHANCE FOR FRIDAY'S HIGH TO BE BELOW 75 DEGREES. CUTOFF LOWS  
ARE WORTH WATCHING FOR, AS SOUTHERLY FLOW AROUND THEM CAN BRING  
INCREASED THUNDERSTORM CHANCES. THESE FEATURES ARE LARGELY ABSENT IN  
DETERMINISTIC IMAGERY DURING THE WEEK, BUT SOME PASS BY NEXT  
WEEKEND. CUTOFF LOWS ARE FICKLE, SO THIS IS MORE OF A NOTE OF  
INTEREST RATHER THAN A CONFIDENT FORECAST OF ACTIVITY FOR NEXT  
WEEKEND. -TAD  
 
 
   
AVIATION...26/12Z TAFS  
ONSHORE FLOW IS BRINGING MVFR CEILINGS TO  
THE OREGON COAST. COASTAL AREAS COULD RETURN TO VFR LEVELS EARLY  
THIS AFTERNOON WITH MVFR CEILINGS EXPECTED TO RETURN IN THE EVENING  
 
MVFR TO IFR CEILINGS ARE PRESENT OVER SOUTHERN SISKIYOU AND MODOC  
COUNTIES. THESE AREAS HAVE 40-60% CHANCE FOR PRECIPITATION THROUGH  
THE MORNING AND AFTERNOON, AS WELL AS 10-20% CHANCE FOR AFTERNOON  
THUNDERSTORMS. ACTIVITY AND CLOUD COVER EASES INTO THE NIGHT, WITH  
VFR LEVELS EXPECTED.  
 
OTHER AREAS WILL GENERALLY SEE VFR LEVELS THROUGH THE TAF PERIOD.  
ISOLATED TO SCATTERED SHOWERS ARE POSSIBLE ALONG AND EAST OF THE  
CASCADES THIS AFTERNOON AND EVENING, AS WELL AS SLIGHT CHANCES OVER  
EASTERN DOUGLAS COUNTY. WHILE SHOWERS ARE GENERALLY NOT EXPECTED TO  
AFFECT AREA TERMINALS, A PASSING SHOWER CAN LOCALLY AFFECT CEILINGS  
AND VISIBILITY. -TAD  
 
 
   
MARINE...UPDATED 300 AM PDT SUNDAY, APRIL 26, 2026  
WINDS AND SWELL  
EASE TO BELOW ADVISORY LEVELS THIS MORNING. NORTH WINDS CONTINUE  
INTO THE WEEK AHEAD, BUT STAY BELOW ADVISORY SPEEDS THROUGH  
MONDAY. GUSTY NORTH WINDS DEVELOP ON TUESDAY MORNING, ESPECIALLY  
SOUTH OF CAPE BLANCO. STEEP SEAS SOUTH OF CAPE BLANCO ARE POSSIBLE  
BY TUESDAY AFTERNOON AND FARTHER NORTH BY WEDNESDAY MORNING. HIGH  
END ADVISORY LEVEL WINDS ARE POSSIBLE LATE IN THE WEEK, WITH  
AREAS OF GALES SOUTH OF GOLD BEACH ALSO POSSIBLE.  
 
 
   
MFR WATCHES/WARNINGS/ADVISORIES  
 
OR...NONE.  
 
CA...NONE.  
 
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 5 AM PDT EARLY  
THIS MORNING FOR PZZ356-376.  
 
 
 
 
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